Sortix volatile manual

This manual documents Sortix volatile, a development build that has not been officially released. You can instead view this document in the latest official manual.

NAME

openssl — OpenSSL command line tool

SYNOPSIS

openssl

command [command_opt ...] [command_arg ...]

openssl

openssl

no-command

DESCRIPTION

OpenSSL is a cryptography toolkit implementing the Transport Layer Security (TLS) network protocol, as well as related cryptography standards.

The openssl program is a command line tool for using the various cryptography functions of openssl's crypto library from the shell.

The pseudo-commands list-standard-commands, list-message-digest-commands, and list-cipher-commands output a list (one entry per line) of the names of all standard commands, message digest commands, or cipher commands, respectively, that are available in the present openssl utility.

The pseudo-commands list-cipher-algorithms and list-message-digest-algorithms list all cipher and message digest names, one entry per line. Aliases are listed as:

from => to

The pseudo-command list-public-key-algorithms lists all supported public key algorithms.

The pseudo-command no-command tests whether a command of the specified name is available. If command does not exist, it returns 0 and prints no-command; otherwise it returns 1 and prints command. In both cases, the output goes to stdout and nothing is printed to stderr. Additional command line arguments are always ignored. Since for each cipher there is a command of the same name, this provides an easy way for shell scripts to test for the availability of ciphers in the openssl program.

Note: no-command is not able to detect pseudo-commands such as quit, list-...-commands, or no-command itself.

ASN1PARSE

openssl asn1parse: [-i] [-dlimit number] [-dump] [-genconf file] [-genstr str] [-in file] [-inform der | pem | txt] [-length number] [-noout] [-offset number] [-oid file] [-out file] [-strparse offset]

The asn1parse command is a diagnostic utility that can parse ASN.1 structures. It can also be used to extract data from ASN.1 formatted data.

The options are as follows:

CA

openssl ca: [-batch] [-cert file] [-config file] [-create_serial] [-crl_CA_compromise time] [-crl_compromise time] [-crl_hold instruction] [-crl_reason reason] [-crldays days] [-crlexts section] [-crlhours hours] [-crlsec seconds] [-days arg] [-enddate date] [-extensions section] [-extfile file] [-gencrl] [-in file] [-infiles] [-key password] [-keyfile file] [-keyform pem | der] [-md alg] [-msie_hack] [-multivalue-rdn] [-name section] [-noemailDN] [-notext] [-out file] [-outdir directory] [-passin arg] [-policy arg] [-preserveDN] [-revoke file] [-selfsign] [-sigopt nm:v] [-ss_cert file] [-startdate date] [-status serial] [-subj arg] [-updatedb] [-utf8] [-verbose]

The ca command is a minimal certificate authority (CA) application. It can be used to sign certificate requests in a variety of forms and generate certificate revocation lists (CRLs). It also maintains a text database of issued certificates and their status.

The options relevant to CAs are as follows:

-batch: Batch mode. In this mode no questions will be asked and all certificates will be certified automatically.
-cert file: The CA certificate file.
-config file: Specify an alternative configuration file.
-create_serial: If reading the serial from the text file as specified in the configuration fails, create a new random serial to be used as the next serial number.
-days arg: The number of days to certify the certificate for.
-enddate date: Set the expiry date. The format of the date is [YY]YYMMDDHHMMSSZ, with all four year digits required for dates from 2050 onwards.
-extensions section: The section of the configuration file containing certificate extensions to be added when a certificate is issued (defaults to x509_extensions unless the -extfile option is used). If no extension section is present, a V1 certificate is created. If the extension section is present (even if it is empty), then a V3 certificate is created. See the x509v3.cnf(5) manual page for details of the extension section format.
-extfile file: An additional configuration file to read certificate extensions from (using the default section unless the -extensions option is also used).
-in file: An input file containing a single certificate request to be signed by the CA.
-infiles: If present, this should be the last option; all subsequent arguments are assumed to be the names of files containing certificate requests.
-key password: The password used to encrypt the private key. Since on some systems the command line arguments are visible, this option should be used with caution.
-keyfile file: The private key to sign requests with.
-keyform pem | der: Private key file format. The default is pem.
-md alg: The message digest to use. Possible values include md5 and sha1. This option also applies to CRLs.
-msie_hack: This is a legacy option to make ca work with very old versions of the IE certificate enrollment control “certenr3”. It used UniversalStrings for almost everything. Since the old control has various security bugs, its use is strongly discouraged. The newer control “Xenroll” does not need this option.
-multivalue-rdn: This option causes the -subj argument to be interpreted with full support for multivalued RDNs, for example “/DC=org/DC=OpenSSL/DC=users/UID=123456+CN=John Doe”. If -multivalue-rdn is not used, the UID value is set to “123456+CN=John Doe”.
-name section: Specifies the configuration file section to use (overrides default_ca in the ca section).
-noemailDN: The DN of a certificate can contain the EMAIL field if present in the request DN, however it is good policy just having the email set into the altName extension of the certificate. When this option is set, the EMAIL field is removed from the certificate's subject and set only in the, eventually present, extensions. The email_in_dn keyword can be used in the configuration file to enable this behaviour.
-notext: Don't output the text form of a certificate to the output file.
-out file: The output file to output certificates to. The default is standard output. The certificate details will also be printed out to this file in PEM format.
-outdir directory: The directory to output certificates to. The certificate will be written to a file consisting of the serial number in hex with “.pem” appended.
-passin arg: The key password source.
-policy arg: Define the CA “policy” to use. The policy section in the configuration file consists of a set of variables corresponding to certificate DN fields. The values may be one of “match” (the value must match the same field in the CA certificate), “supplied” (the value must be present), or “optional” (the value may be present). Any fields not mentioned in the policy section are silently deleted, unless the -preserveDN option is set, but this can be regarded more of a quirk than intended behaviour.
-preserveDN: Normally, the DN order of a certificate is the same as the order of the fields in the relevant policy section. When this option is set, the order is the same as the request. This is largely for compatibility with the older IE enrollment control which would only accept certificates if their DNs matched the order of the request. This is not needed for Xenroll.
-selfsign: Indicates the issued certificates are to be signed with the key the certificate requests were signed with, given with -keyfile. Certificate requests signed with a different key are ignored. If -gencrl or -ss_cert are given, -selfsign is ignored.

A consequence of using -selfsign is that the self-signed certificate appears among the entries in the certificate database (see the configuration option database) and uses the same serial number counter as all other certificates signed with the self-signed certificate.
-sigopt nm:v: Pass options to the signature algorithm during sign or certify operations. The names and values of these options are algorithm-specific.
-ss_cert file: A single self-signed certificate to be signed by the CA.
-startdate date: Set the start date. The format of the date is [YY]YYMMDDHHMMSSZ, with all four year digits required for dates from 2050 onwards.
-subj arg: Supersedes the subject name given in the request. The arg must be formatted as /type0=value0/type1=value1/type2=...; characters may be escaped by ‘\’ (backslash), no spaces are skipped.
-utf8: Interpret field values read from a terminal or obtained from a configuration file as UTF-8 strings. By default, they are interpreted as ASCII.
-verbose: Print extra details about the operations being performed.

The options relevant to CRLs are as follows:

Many of the options can be set in the ca section of the configuration file (or in the default section of the configuration file), specified using default_ca or -name. The options preserve and msie_hack are read directly from the ca section.

Many of the configuration file options are identical to command line options. Where the option is present in the configuration file and the command line, the command line value is used. Where an option is described as mandatory, then it must be present in the configuration file or the command line equivalent (if any) used.

certificate: The same as -cert. It gives the file containing the CA certificate. Mandatory.
copy_extensions: Determines how extensions in certificate requests should be handled. If set to none or this option is not present, then extensions are ignored and not copied to the certificate. If set to copy, then any extensions present in the request that are not already present are copied to the certificate. If set to copyall, then all extensions in the request are copied to the certificate: if the extension is already present in the certificate it is deleted first.

The copy_extensions option should be used with caution. If care is not taken, it can be a security risk. For example, if a certificate request contains a basicConstraints extension with CA:TRUE and the copy_extensions value is set to copyall and the user does not spot this when the certificate is displayed, then this will hand the requester a valid CA certificate.

This situation can be avoided by setting copy_extensions to copy and including basicConstraints with CA:FALSE in the configuration file. Then if the request contains a basicConstraints extension, it will be ignored.

The main use of this option is to allow a certificate request to supply values for certain extensions such as subjectAltName.
crl_extensions: The same as -crlexts.
crlnumber: A text file containing the next CRL number to use in hex. The CRL number will be inserted in the CRLs only if this file exists. If this file is present, it must contain a valid CRL number.
database: The text database file to use. Mandatory. This file must be present, though initially it will be empty.
default_crl_hours, default_crl_days: The same as the -crlhours and -crldays options. These will only be used if neither command line option is present. At least one of these must be present to generate a CRL.
default_days: The same as the -days option. The number of days to certify a certificate for.
default_enddate: The same as the -enddate option. Either this option or default_days (or the command line equivalents) must be present.
default_md: The same as the -md option. The message digest to use. Mandatory.
default_startdate: The same as the -startdate option. The start date to certify a certificate for. If not set, the current time is used.
email_in_dn: The same as -noemailDN. If the EMAIL field is to be removed from the DN of the certificate, simply set this to “no”. If not present, the default is to allow for the EMAIL field in the certificate's DN.
msie_hack: The same as -msie_hack.
name_opt, cert_opt: These options allow the format used to display the certificate details when asking the user to confirm signing. All the options supported by the x509 utilities' -nameopt and -certopt switches can be used here, except that no_signame and no_sigdump are permanently set and cannot be disabled (this is because the certificate signature cannot be displayed because the certificate has not been signed at this point).

For convenience, the value ca_default is accepted by both to produce a reasonable output.

If neither option is present, the format used in earlier versions of openssl is used. Use of the old format is strongly discouraged because it only displays fields mentioned in the policy section, mishandles multicharacter string types and does not display extensions.
new_certs_dir: The same as the -outdir command line option. It specifies the directory where new certificates will be placed. Mandatory.
oid_file: This specifies a file containing additional object identifiers. Each line of the file should consist of the numerical form of the object identifier followed by whitespace, then the short name followed by whitespace and finally the long name.
oid_section: This specifies a section in the configuration file containing extra object identifiers. Each line should consist of the short name of the object identifier followed by ‘=’ and the numerical form. The short and long names are the same when this option is used.
policy: The same as -policy. Mandatory.
preserve: The same as -preserveDN.
private_key: Same as the -keyfile option. The file containing the CA private key. Mandatory.
serial: A text file containing the next serial number to use in hex. Mandatory. This file must be present and contain a valid serial number.
unique_subject: If the value yes is given, the valid certificate entries in the database must have unique subjects. If the value no is given, several valid certificate entries may have the exact same subject. The default value is yes.

Note that it is valid in some circumstances for certificates to be created without any subject. In cases where there are multiple certificates without subjects this does not count as a duplicate.
x509_extensions: The same as -extensions.

CERTHASH

openssl certhash: [-nv] dir ...

The certhash command calculates a hash value of “.pem” file in the specified directory list and creates symbolic links for each file, where the name of the link is the hash value. See the SSL_CTX_load_verify_locations(3) manual page for how hash links are used.

The links created are of the form “HHHHHHHH.D”, where each ‘H’ is a hexadecimal character and ‘D’ is a single decimal digit. The hashes for CRLs look similar, except the letter ‘r’ appears after the period, like this: “HHHHHHHH.rD”. When processing a directory, certhash will first remove all links that have a name in that syntax and invalid reference.

Multiple objects may have the same hash; they will be indicated by incrementing the ‘D’ value. Duplicates are found by comparing the full SHA256 fingerprint. A warning will be displayed if a duplicate is found.

A warning will also be displayed if there are files that cannot be parsed as either a certificate or a CRL.

The options are as follows:

CIPHERS

openssl ciphers [-hsVv] [-tls1_2] [-tls1_3] [control]

The ciphers command converts the control string from the format documented in SSL_CTX_set_cipher_list(3) into an ordered SSL cipher suite preference list. If no control string is specified, the DEFAULT list is printed.

The options are as follows:

CMS

openssl cms: [-aes128 | -aes192 | -aes256 | -camellia128 | -camellia192 | -camellia256 | -des | -des3 | -rc2-40 | -rc2-64 | -rc2-128] [-CAfile file] [-CApath directory] [-CRLfile file] [-binary] [-certfile file] [-certsout file] [-cmsout] [-compress] [-content file] [-crlfeol] [-data_create] [-data_out] [-debug_decrypt] [-decrypt] [-digest_create] [-digest_verify] [-econtent_type type] [-encrypt] [-EncryptedData_decrypt] [-EncryptedData_encrypt] [-from addr] [-in file] [-inform der | pem | smime] [-inkey file] [-keyform der | pem] [-keyid] [-keyopt nm:v] [-md digest] [-no_attr_verify] [-no_content_verify] [-no_signer_cert_verify] [-noattr] [-nocerts] [-nodetach] [-nointern] [-nooldmime] [-noout] [-nosigs] [-nosmimecap] [-noverify] [-out file] [-outform der | pem | smime] [-passin src] [-print] [-pwri_password arg] [-rctform der | pem | smime] [-receipt_request_all | -receipt_request_first] [-receipt_request_from addr] [-receipt_request_print] [-receipt_request_to addr] [-recip file] [-resign] [-secretkey key] [-secretkeyid id] [-sign] [-sign_receipt] [-signer file] [-stream | -indef | -noindef] [-subject s] [-text] [-to addr] [-uncompress] [-verify] [-verify_receipt file] [-verify_retcode] [cert.pem ...]

The cms command handles S/MIME v3.1 mail. It can encrypt, decrypt, sign and verify, compress and uncompress S/MIME messages.

The MIME message must be sent without any blank lines between the headers and the output. Some mail programs will automatically add a blank line. Piping the mail directly to sendmail is one way to achieve the correct format.

The supplied message to be signed or encrypted must include the necessary MIME headers or many S/MIME clients won't display it properly (if at all). You can use the -text option to automatically add plain text headers.

A "signed and encrypted" message is one where a signed message is then encrypted. This can be produced by encrypting an already signed message.

There are various operation options that set the type of operation to be performed. The meaning of the other options varies according to the operation type.

The remaining options are as follows:

-aes128 | -aes192 | -aes256 | -camellia128 | -camellia192 | -camellia256 | -des | -des3 | -rc2-40 | -rc2-64 | -rc2-128: The encryption algorithm to use. 128-, 192-, or 256-bit AES, 128-, 192-, or 256-bit CAMELLIA, DES (56 bits), triple DES (168 bits), or 40-, 64-, or 128-bit RC2, respectively; if not specified, triple DES is used. Only used with -encrypt and -EncryptedData_encrypt commands.
-binary: Normally the input message is converted to "canonical" format which is effectively using CR/LF as end of line, as required by the S/MIME specification. When this option is present, no translation occurs. This is useful when handling binary data which may not be in MIME format.
-CAfile file: A file containing trusted CA certificates, used with -verify and -verify_receipt.
-CApath directory: A directory containing trusted CA certificates, used with -verify and -verify_receipt. This directory must be a standard certificate directory: that is a hash of each subject name (using x509 -hash) should be linked to each certificate.
-CRLfile file: Allows additional certificate revocation lists to be specified for verification. The CRLs should be in PEM format.
cert.pem ...: One or more certificates of message recipients: used when encrypting a message.
-certfile file: Allows additional certificates to be specified. When signing, these will be included with the message. When verifying, these will be searched for the signer's certificates. The certificates should be in PEM format.
-certsout file: A file that any certificates contained in the message are written to.
-check_ss_sig, -crl_check, -crl_check_all, -extended_crl, -ignore_critical, -issuer_checks, -policy, -policy_check, -purpose, -x509_strict: Set various certificate chain validation options. See the verify command for details.
-content file: A file containing the detached content. This is only useful with the -verify command. This is only usable if the CMS structure is using the detached signature form where the content is not included. This option will override any content if the input format is S/MIME and it uses the multipart/signed MIME content type.
-crlfeol: Output a S/MIME message with CR/LF end of line.
-debug_decrypt: Set the CMS_DEBUG_DECRYPT flag when decrypting. This option should be used with caution, since this can be used to disable the MMA attack protection and return an error if no recipient can be found. See the CMS_decrypt(3) manual page for details of the flag.
-from addr, -subject s, -to addr: The relevant mail headers. These are included outside the signed portion of a message so they may be included manually. If signing then many S/MIME mail clients check the signer's certificate's email address matches that specified in the From: address.
-econtent_type type: Set the encapsulated content type, used with -sign. If not supplied, the Data type is used. The type argument can be any valid OID name in either text or numerical format.
-in file: The input message to be encrypted or signed or the message to be decrypted or verified.
-inform der | pem | smime: The input format for the CMS structure. The default is smime, which reads an S/MIME format message. pem and der format change this to expect PEM and DER format CMS structures instead. This currently only affects the input format of the CMS structure; if no CMS structure is being input (for example with -encrypt or -sign) this option has no effect.
-inkey file: The private key to use when signing or decrypting. This must match the corresponding certificate. If this option is not specified then the private key must be included in the certificate file specified with the -recip or -signer file. When signing, this option can be used multiple times to specify successive keys.
-keyform der | pem: Input private key format. The default is pem.
-keyid: Use subject key identifier to identify certificates instead of issuer name and serial number. The supplied certificate must include a subject key identifier extension. Supported by -sign and -encrypt operations.
-keyopt nm:v: Set customised parameters for the preceding key or certificate for encryption and signing. It can currently be used to set RSA-PSS for signing, RSA-OAEP for encryption or to modify default parameters for ECDH. This option can be used multiple times.
-md digest: The digest algorithm to use when signing or resigning. If not present then the default digest algorithm for the signing key will be used (usually SHA1).
-no_attr_verify: Do not verify the signer's attribute of a signature.
-no_content_verify: Do not verify the content of a signed message.
-no_signer_cert_verify: Do not verify the signer's certificate of a signed message.
-noattr: Do not include attributes. Normally when a message is signed a set of attributes are included which include the signing time and supported symmetric algorithms. With this option they are not included.
-nocerts: Do not include the signer's certificate. This will reduce the size of the signed message but the verifier must have a copy of the signer's certificate available locally (passed using the -certfile option for example).
-nodetach: When signing a message, use opaque signing. This form is more resistant to translation by mail relays but it cannot be read by mail agents that do not support S/MIME. Without this option cleartext signing with the MIME type multipart/signed is used.
-nointern: Only the certificates specified in the -certfile option are used. When verifying a message, normally certificates (if any) included in the message are searched for the signing certificate. The supplied certificates can still be used as untrusted CAs however.
-nooldmime: Output an old S/MIME content type like "application/x-pkcs7-".
-noout: Do not output the parsed CMS structure for the -cmsout operation. This is useful when combined with the -print option or if the syntax of the CMS structure is being checked.
-nosigs: Do not try to verify the signatures on the message.
-nosmimecap: Exclude the list of supported algorithms from signed attributes; other options such as signing time and content type are still included.
-noverify: Do not verify the signer's certificate of a signed message.
-out file: The message text that has been decrypted or verified or the output MIME format message that has been signed or verified.
-outform der | pem | smime: This specifies the output format for the CMS structure. The default is smime, which writes an S/MIME format message. pem and der format change this to write PEM and DER format CMS structures instead. This currently only affects the output format of the CMS structure; if no CMS structure is being output (for example with -verify or -decrypt) this option has no effect.
-passin src: The private key password source.
-print: Print out all fields of the CMS structure for the -cmsout operation. This is mainly useful for testing purposes.
-pwri_password arg: Specify PasswordRecipientInfo (PWRI) password to use. Supported by the -encrypt and -decrypt operations.
-rctform der | pem | smime: Specify the format for a signed receipt for use with the -receipt_verify operation. The default is smime.
-receipt_request_all | -receipt_request_first: Indicate requests should be provided by all recipient or first tier recipients (those mailed directly and not from a mailing list), for the -sign operation to include a signed receipt request. Ignored if -receipt_request_from is included.
-receipt_request_from addr: Add an explicit email address where receipts should be supplied.
-receipt_request_print: Print out the contents of any signed receipt requests for the -verify operation.
-receipt_request_to addr: Add an explicit email address where signed receipts should be sent to. This option must be supplied if a signed receipt is requested.
-recip file: When decrypting a message, this specifies the recipient's certificate. The certificate must match one of the recipients of the message or an error occurs. When encrypting a message, this option may be used multiple times to specify each recipient. This form must be used if customised parameters are required (for example to specify RSA-OAEP). Only certificates carrying RSA, Diffie-Hellman or EC keys are supported by this option.
-secretkey key: Specify symmetric key to use. The key must be supplied in hex format and be consistent with the algorithm used. Supported by the -EncryptedData_encrypt, -EncryptedData_decrypt, -encrypt and -decrypt operations. When used with -encrypt or -decrypt, the supplied key is used to wrap or unwrap the content encryption key using an AES key in the KEKRecipientInfo type.
-secretkeyid id: The key identifier for the supplied symmetric key for KEKRecipientInfo type. This option must be present if the -secretkey option is used with -encrypt. With -decrypt operations the id is used to locate the relevant key; if it is not supplied then an attempt is used to decrypt any KEKRecipientInfo structures.
-signer file: A signing certificate when signing or resigning a message; this option can be used multiple times if more than one signer is required. If a message is being verified then the signers certificates will be written to this file if the verification was successful.
-stream | -indef | -noindef: The -stream and -indef options are equivalent and enable streaming I/O for encoding operations. This permits single pass processing of data without the need to hold the entire contents in memory, potentially supporting very large files. Streaming is automatically set for S/MIME signing with detached data if the output format is smime; it is currently off by default for all other operations. -noindef disable streaming I/O where it would produce an indefinite length constructed encoding. This option currently has no effect.
-text: Add plain text (text/plain) MIME headers to the supplied message if encrypting or signing. If decrypting or verifying, it strips off text headers: if the decrypted or verified message is not of MIME type text/plain then an error occurs.
-verify_retcode: Set verification error code to exit code to indicate what verification error has occurred. Supported by -verify operation only. Exit code value minus 32 shows verification error code. See verify command for the list of verification error code.

The exit codes for cms are as follows:

CRL

openssl crl: [-CAfile file] [-CApath dir] [-crlnumber] [-fingerprint] [-hash] [-hash_old] [-in file] [-inform der | pem] [-issuer] [-lastupdate] [-nameopt option] [-nextupdate] [-noout] [-out file] [-outform der | pem] [-text] [-verify]

The crl command processes CRL files in DER or PEM format.

The options are as follows:

CRL2PKCS7

openssl crl2pkcs7: [-certfile file] [-in file] [-inform der | pem] [-nocrl] [-out file] [-outform der | pem]

The crl2pkcs7 command takes an optional CRL and one or more certificates and converts them into a PKCS#7 degenerate “certificates only” structure.

The options are as follows:

DGST

openssl dgst: [-cdr] [-binary] [-digest] [-hex] [-hmac key] [-keyform pem] [-mac algorithm] [-macopt nm:v] [-out file] [-passin arg] [-prverify file] [-sign file] [-signature file] [-sigopt nm:v] [-verify file] [file ...]

The digest functions output the message digest of a supplied file or files in hexadecimal form. They can also be used for digital signing and verification.

The options are as follows:

DHPARAM

openssl dhparam: [-2 | -5] [-C] [-check] [-dsaparam] [-in file] [-inform der | pem] [-noout] [-out file] [-outform der | pem] [-text] [numbits]

The dhparam command is used to manipulate DH parameter files. Only the older PKCS#3 DH is supported, not the newer X9.42 DH.

The options are as follows:

DSA

openssl dsa: [-aes128 | -aes192 | -aes256 | -des | -des3] [-in file] [-inform der | pem | pvk] [-modulus] [-noout] [-out file] [-outform der | pem | pvk] [-passin arg] [-passout arg] [-pubin] [-pubout] [-pvk-none | -pvk-strong | -pvk-weak] [-text]

The dsa command processes DSA keys. They can be converted between various forms and their components printed out.

Note: This command uses the traditional SSLeay compatible format for private key encryption: newer applications should use the more secure PKCS#8 format using the pkcs8 command.

The options are as follows:

DSAPARAM

openssl dsaparam: [-C] [-genkey] [-in file] [-inform der | pem] [-noout] [-out file] [-outform der | pem] [-text] [numbits]

The dsaparam command is used to manipulate or generate DSA parameter files.

The options are as follows:

EC

openssl ec: [-conv_form arg] [-des] [-des3] [-in file] [-inform der | pem] [-noout] [-out file] [-outform der | pem] [-param_enc arg] [-param_out] [-passin arg] [-passout arg] [-pubin] [-pubout] [-text]

The ec command processes EC keys. They can be converted between various forms and their components printed out. openssl uses the private key format specified in “SEC 1: Elliptic Curve Cryptography” (https://www.secg.org/). To convert an EC private key into the PKCS#8 private key format use the pkcs8 command.

The options are as follows:

ECPARAM

openssl ecparam: [-C] [-check] [-conv_form arg] [-genkey] [-in file] [-inform der | pem] [-list_curves] [-name arg] [-no_seed] [-noout] [-out file] [-outform der | pem] [-param_enc arg] [-text]

The ecparam command is used to manipulate or generate EC parameter files. openssl is not able to generate new groups so ecparam can only create EC parameters from known (named) curves.

The options are as follows:

ENC

openssl enc: -ciphername [-AadePpv] [-base64] [-bufsize number] [-debug] [-in file] [-iter iterations] [-iv IV] [-K key] [-k password] [-kfile file] [-md digest] [-none] [-nopad] [-nosalt] [-out file] [-pass arg] [-pbkdf2] [-S salt] [-salt]

The symmetric cipher commands allow data to be encrypted or decrypted using various block and stream ciphers using keys based on passwords or explicitly provided. Base64 encoding or decoding can also be performed either by itself or in addition to the encryption or decryption. The program can be called either as openssl ciphername or openssl enc -ciphername.

Some of the ciphers do not have large keys and others have security implications if not used correctly. All the block ciphers normally use PKCS#5 padding, also known as standard block padding. If padding is disabled, the input data must be a multiple of the cipher block length.

The options are as follows:

-A: If the -a option is set, then base64 process the data on one line.
-a, -base64: Base64 process the data. This means that if encryption is taking place, the data is base64-encoded after encryption. If decryption is set, the input data is base64-decoded before being decrypted.
-bufsize number: Set the buffer size for I/O.
-d: Decrypt the input data.
-debug: Debug the BIOs used for I/O.
-e: Encrypt the input data. This is the default.
-in file: The input file to read from, or standard input if not specified.
-iter iterations: Use the pbkdf2 key derivation function, with iterations as the number of iterations.
-iv IV: The actual IV (initialisation vector) to use: this must be represented as a string comprised only of hex digits. When only the key is specified using the -K option, the IV must explicitly be defined. When a password is being specified using one of the other options, the IV is generated from this password.
-K key: The actual key to use: this must be represented as a string comprised only of hex digits. If only the key is specified, the IV must also be specified using the -iv option. When both a key and a password are specified, the key given with the -K option will be used and the IV generated from the password will be taken. It probably does not make much sense to specify both key and password.
-k password: The password to derive the key from. Superseded by the -pass option.
-kfile file: Read the password to derive the key from the first line of file. Superseded by the -pass option.
-md digest: Use digest to create a key from a pass phrase. Currently, the default value is sha256.
-none: Use NULL cipher (no encryption or decryption of input).
-nopad: Disable standard block padding.
-nosalt: Don't use a salt in the key derivation routines. This option should never be used since it makes it possible to perform efficient dictionary attacks on the password and to attack stream cipher encrypted data.
-out file: The output file to write to, or standard output if not specified.
-P: Print out the salt, key, and IV used, then immediately exit; don't do any encryption or decryption.
-p: Print out the salt, key, and IV used.
-pass arg: The password source.
-pbkdf2: Use the pbkdf2 key derivation function, with the default of 10000 iterations.
-S salt: The actual salt to use: this must be represented as a string comprised only of hex digits.
-salt: Use a salt in the key derivation routines (the default). When the salt is being used, the first eight bytes of the encrypted data are reserved for the salt: it is randomly generated when encrypting a file and read from the encrypted file when it is decrypted.
-v: Print extra details about the processing.

ERRSTR

openssl errstr errno ...

The errstr command performs error number to error string conversion, generating a human-readable string representing the error code errno. The string is obtained through the ERR_error_string_n(3) function and has the following format:

error:[error code]:[library name]:[function name]:[reason string]

[error code] is an 8-digit hexadecimal number. The remaining fields [library name], [function name], and [reason string] are all ASCII text.

GENDSA

openssl gendsa: [-aes128 | -aes192 | -aes256 | -camellia128 | -camellia192 | -camellia256 | -des | -des3 | -idea] [-out file] [-passout arg] paramfile

The gendsa command generates a DSA private key from a DSA parameter file (typically generated by the openssl dsaparam command). DSA key generation is little more than random number generation so it is much quicker than, for example, RSA key generation.

The options are as follows:

GENPKEY

openssl genpkey: [-algorithm alg] [cipher] [-genparam] [-out file] [-outform der | pem] [-paramfile file] [-pass arg] [-pkeyopt opt:value] [-text]

The genpkey command generates private keys. The use of this program is encouraged over the algorithm specific utilities because additional algorithm options can be used.

The options are as follows:

GENRSA

openssl genrsa: [-3 | -f4] [-aes128 | -aes192 | -aes256 | -camellia128 | -camellia192 | -camellia256 | -des | -des3 | -idea] [-out file] [-passout arg] [numbits]

The genrsa command generates an RSA private key, which essentially involves the generation of two prime numbers. When generating the key, various symbols will be output to indicate the progress of the generation. A ‘.’ represents each number which has passed an initial sieve test; ‘+’ means a number has passed a single round of the Miller-Rabin primality test; ‘*’ means the number has failed primality testing and needs to be generated afresh. A newline means that the number has passed all the prime tests (the actual number depends on the key size).

The options are as follows:

OCSP

openssl ocsp: [-CA file] [-CAfile file] [-CApath directory] [-cert file] [-dgst alg] [-header name value] [-host hostname:port] [-ignore_err] [-index indexfile] [-issuer file] [-ndays days] [-nmin minutes] [-no_cert_checks] [-no_cert_verify] [-no_certs] [-no_chain] [-no_explicit] [-no_intern] [-no_nonce] [-no_signature_verify] [-nonce] [-noverify] [-nrequest number] [-out file] [-path path] [-port portnum] [-req_text] [-reqin file] [-reqout file] [-resp_key_id] [-resp_no_certs] [-resp_text] [-respin file] [-respout file] [-rkey file] [-rother file] [-rsigner file] [-serial num] [-sign_other file] [-signer file] [-signkey file] [-status_age age] [-text] [-timeout seconds] [-trust_other] [-url responder_url] [-VAfile file] [-validity_period nsec] [-verify_other file]

The Online Certificate Status Protocol (OCSP) enables applications to determine the (revocation) state of an identified certificate (RFC 2560).

The ocsp command performs many common OCSP tasks. It can be used to print out requests and responses, create requests and send queries to an OCSP responder, and behave like a mini OCSP server itself.

The options are as follows:

-CAfile file, -CApath directory: A file or path containing trusted CA certificates, used to verify the signature on the OCSP response.
-cert file: Add the certificate file to the request. The issuer certificate is taken from the previous -issuer option, or an error occurs if no issuer certificate is specified.
-dgst alg: Use the digest algorithm alg for certificate identification in the OCSP request. By default SHA1 is used.
-host hostname:port, -path path: Send the OCSP request to hostname on port. -path specifies the HTTP path name to use, or / by default.
-header name value: Add the header name with the specified value to the OCSP request that is sent to the responder. This may be repeated.
-issuer file: The current issuer certificate, in PEM format. Can be used multiple times and must come before any -cert options.
-no_cert_checks: Don't perform any additional checks on the OCSP response signer's certificate. That is, do not make any checks to see if the signer's certificate is authorised to provide the necessary status information: as a result this option should only be used for testing purposes.
-no_cert_verify: Don't verify the OCSP response signer's certificate at all. Since this option allows the OCSP response to be signed by any certificate, it should only be used for testing purposes.
-no_certs: Don't include any certificates in the signed request.
-no_chain: Do not use certificates in the response as additional untrusted CA certificates.
-no_explicit: Don't check the explicit trust for OCSP signing in the root CA certificate.
-no_intern: Ignore certificates contained in the OCSP response when searching for the signer's certificate. The signer's certificate must be specified with either the -verify_other or -VAfile options.
-no_signature_verify: Don't check the signature on the OCSP response. Since this option tolerates invalid signatures on OCSP responses, it will normally only be used for testing purposes.
-nonce, -no_nonce: Add an OCSP nonce extension to a request, or disable an OCSP nonce addition. Normally, if an OCSP request is input using the -respin option no nonce is added: using the -nonce option will force the addition of a nonce. If an OCSP request is being created (using the -cert and -serial options), a nonce is automatically added; specifying -no_nonce overrides this.
-noverify: Don't attempt to verify the OCSP response signature or the nonce values. This is normally only be used for debugging since it disables all verification of the responder's certificate.
-out file: Specify the output file to write to, or standard output if not specified.
-req_text, -resp_text, -text: Print out the text form of the OCSP request, response, or both, respectively.
-reqin file, -respin file: Read an OCSP request or response file from file. These options are ignored if an OCSP request or response creation is implied by other options (for example with the -serial, -cert, and -host options).
-reqout file, -respout file: Write out the DER-encoded certificate request or response to file.
-serial num: Same as the -cert option except the certificate with serial number num is added to the request. The serial number is interpreted as a decimal integer unless preceded by ‘0x’. Negative integers can also be specified by preceding the value with a minus sign.
-sign_other file: Additional certificates to include in the signed request.
-signer file, -signkey file: Sign the OCSP request using the certificate specified in the -signer option and the private key specified by the -signkey option. If the -signkey option is not present, then the private key is read from the same file as the certificate. If neither option is specified, the OCSP request is not signed.
-timeout seconds: Connection timeout to the OCSP responder in seconds.
-trust_other: The certificates specified by the -verify_other option should be explicitly trusted and no additional checks will be performed on them. This is useful when the complete responder certificate chain is not available or trusting a root CA is not appropriate.
-url responder_url: Specify the responder URL. Both HTTP and HTTPS (SSL/TLS) URLs can be specified.
-VAfile file: A file containing explicitly trusted responder certificates. Equivalent to the -verify_other and -trust_other options.
-validity_period nsec, -status_age age: The range of times, in seconds, which will be tolerated in an OCSP response. Each certificate status response includes a notBefore time and an optional notAfter time. The current time should fall between these two values, but the interval between the two times may be only a few seconds. In practice the OCSP responder and clients' clocks may not be precisely synchronised and so such a check may fail. To avoid this the -validity_period option can be used to specify an acceptable error range in seconds, the default value being 5 minutes.

If the notAfter time is omitted from a response, it means that new status information is immediately available. In this case the age of the notBefore field is checked to see it is not older than age seconds old. By default, this additional check is not performed.
-verify_other file: A file containing additional certificates to search when attempting to locate the OCSP response signing certificate. Some responders omit the actual signer's certificate from the response, so this can be used to supply the necessary certificate.

The options for the OCSP server are as follows:

Initially the OCSP responder certificate is located and the signature on the OCSP request checked using the responder certificate's public key. Then a normal certificate verify is performed on the OCSP responder certificate building up a certificate chain in the process. The locations of the trusted certificates used to build the chain can be specified by the -CAfile and -CApath options or they will be looked for in the standard openssl certificates directory.

If the initial verify fails, the OCSP verify process halts with an error. Otherwise the issuing CA certificate in the request is compared to the OCSP responder certificate: if there is a match then the OCSP verify succeeds.

Otherwise the OCSP responder certificate's CA is checked against the issuing CA certificate in the request. If there is a match and the OCSPSigning extended key usage is present in the OCSP responder certificate, then the OCSP verify succeeds.

Otherwise the root CA of the OCSP responder's CA is checked to see if it is trusted for OCSP signing. If it is, the OCSP verify succeeds.

If none of these checks is successful, the OCSP verify fails. What this effectively means is that if the OCSP responder certificate is authorised directly by the CA it is issuing revocation information about (and it is correctly configured), then verification will succeed.

If the OCSP responder is a global responder, which can give details about multiple CAs and has its own separate certificate chain, then its root CA can be trusted for OCSP signing. Alternatively, the responder certificate itself can be explicitly trusted with the -VAfile option.

PASSWD

openssl passwd: [-1 | -apr1 | -crypt] [-in file] [-noverify] [-quiet] [-reverse] [-salt string] [-stdin] [-table] [password]

The passwd command computes the hash of a password.

The options are as follows:

PKCS7

openssl pkcs7: [-in file] [-inform der | pem] [-noout] [-out file] [-outform der | pem] [-print] [-print_certs] [-text]

The pkcs7 command processes PKCS#7 files in DER or PEM format. The PKCS#7 routines only understand PKCS#7 v 1.5 as specified in RFC 2315.

The options are as follows:

PKCS8

openssl pkcs8: [-in file] [-inform der | pem] [-nocrypt] [-noiter] [-out file] [-outform der | pem] [-passin arg] [-passout arg] [-topk8] [-v1 alg] [-v2 alg]

The pkcs8 command processes private keys (both encrypted and unencrypted) in PKCS#8 format with a variety of PKCS#5 (v1.5 and v2.0) and PKCS#12 algorithms. The default encryption is only 56 bits; keys encrypted using PKCS#5 v2.0 algorithms and high iteration counts are more secure.

The options are as follows:

PKCS12

openssl pkcs12: [-aes128 | -aes192 | -aes256 | -camellia128 | -camellia192 | -camellia256 | -des | -des3 | -idea] [-cacerts] [-CAfile file] [-caname name] [-CApath directory] [-certfile file] [-certpbe alg] [-chain] [-clcerts] [-descert] [-export] [-in file] [-info] [-inkey file] [-keyex] [-keypbe alg] [-keysig] [-macalg alg] [-maciter] [-name name] [-nocerts] [-nodes] [-noiter] [-nokeys] [-nomac] [-nomaciter] [-nomacver] [-noout] [-out file] [-passin arg] [-passout arg] [-password arg] [-twopass]

The pkcs12 command allows PKCS#12 files (sometimes referred to as PFX files) to be created and parsed. By default, a PKCS#12 file is parsed; a PKCS#12 file can be created by using the -export option.

The options for parsing a PKCS12 file are as follows:

The options for PKCS12 file creation are as follows:

-CAfile file: CA storage as a file.
-CApath directory: CA storage as a directory. The directory must be a standard certificate directory: that is, a hash of each subject name (using x509 -hash) should be linked to each certificate.
-caname name: Specify the “friendly name” for other certificates. May be used multiple times to specify names for all certificates in the order they appear.
-certfile file: A file to read additional certificates from.
-certpbe alg, -keypbe alg: Specify the algorithm used to encrypt the private key and certificates to be selected. Any PKCS#5 v1.5 or PKCS#12 PBE algorithm name can be used. If a cipher name (as output by the list-cipher-algorithms command) is specified then it is used with PKCS#5 v2.0. For interoperability reasons it is advisable to only use PKCS#12 algorithms.
-chain: Include the entire certificate chain of the user certificate. The standard CA store is used for this search. If the search fails, it is considered a fatal error.
-descert: Encrypt the certificate using triple DES; this may render the PKCS#12 file unreadable by some “export grade” software. By default, the private key is encrypted using triple DES and the certificate using 40-bit RC2.
-export: Create a PKCS#12 file (rather than parsing one).
-in file: The input file to read from, or standard input if not specified. The order doesn't matter but one private key and its corresponding certificate should be present. If additional certificates are present, they will also be included in the PKCS#12 file.
-inkey file: File to read a private key from. If not present, a private key must be present in the input file.
-keyex | -keysig: Specify whether the private key is to be used for key exchange or just signing. Normally, “export grade” software will only allow 512-bit RSA keys to be used for encryption purposes, but arbitrary length keys for signing. The -keysig option marks the key for signing only. Signing only keys can be used for S/MIME signing, authenticode (ActiveX control signing) and SSL client authentication.
-macalg alg: Specify the MAC digest algorithm. The default is SHA1.
-maciter: Included for compatibility only: it used to be needed to use MAC iterations counts but they are now used by default.
-name name: Specify the “friendly name” for the certificate and private key. This name is typically displayed in list boxes by software importing the file.
-nomac: Don't attempt to provide the MAC integrity.
-nomaciter, -noiter: Affect the iteration counts on the MAC and key algorithms.

To discourage attacks by using large dictionaries of common passwords, the algorithm that derives keys from passwords can have an iteration count applied to it: this causes a certain part of the algorithm to be repeated and slows it down. The MAC is used to check the file integrity but since it will normally have the same password as the keys and certificates it could also be attacked. By default, both MAC and encryption iteration counts are set to 2048; using these options the MAC and encryption iteration counts can be set to 1. Since this reduces the file security, you should not use these options unless you really have to. Most software supports both MAC and key iteration counts.
-out file: The output file to write to, or standard output if not specified.
-passin arg: The key password source.
-passout arg: The output file password source.
-password arg: With -export, -password is equivalent to -passout. Otherwise, -password is equivalent to -passin.

PKEY

openssl pkey: [cipher] [-in file] [-inform der | pem] [-noout] [-out file] [-outform der | pem] [-passin arg] [-passout arg] [-pubin] [-pubout] [-text] [-text_pub]

The pkey command processes public or private keys. They can be converted between various forms and their components printed out.

The options are as follows:

PKEYPARAM

openssl pkeyparam [-in file] [-noout] [-out file] [-text]

The pkeyparam command processes public or private keys. The key type is determined by the PEM headers.

The options are as follows:

PKEYUTL

openssl pkeyutl: [-asn1parse] [-certin] [-decrypt] [-derive] [-encrypt] [-hexdump] [-in file] [-inkey file] [-keyform der | pem] [-out file] [-passin arg] [-peerform der | pem] [-peerkey file] [-pkeyopt opt:value] [-pubin] [-rev] [-sigfile file] [-sign] [-verify] [-verifyrecover]

The pkeyutl command can be used to perform public key operations using any supported algorithm.

The options are as follows:

-asn1parse

ASN.1 parse the output data. This is useful when combined with the -verifyrecover option when an ASN.1 structure is signed.

-certin

The input is a certificate containing a public key.

-decrypt

Decrypt the input data using a private key.

-derive

Derive a shared secret using the peer key.

-encrypt

Encrypt the input data using a public key.

-hexdump

Hex dump the output data.

-in file

The input file to read from, or standard input if not specified.

-inkey file

The input key file. By default it should be a private key.

-keyform der | pem

The key format.

-out file

The output file to write to, or standard output if not specified.

-passin arg

The key password source.

-peerform der | pem

The peer key format.

-peerkey file

The peer key file, used by key derivation (agreement) operations.

-pkeyopt opt:value

Set the public key algorithm option opt to value. Unless otherwise mentioned, all algorithms support the format digest:alg, which specifies the digest to use for sign, verify, and verifyrecover operations. The value alg should represent a digest name as used in the EVP_get_digestbyname(3) function.

The RSA algorithm supports the encrypt, decrypt, sign, verify, and verifyrecover operations in general. Some padding modes only support some of these operations however.

The DSA algorithm supports the sign and verify operations. Currently there are no additional options other than digest. Only the SHA1 digest can be used and this digest is assumed by default.

The DH algorithm supports the derive operation and no additional options.

The EC algorithm supports the sign, verify, and derive operations. The sign and verify operations use ECDSA and derive uses ECDH. Currently there are no additional options other than digest. Only the SHA1 digest can be used and this digest is assumed by default.

-pubin

The input file is a public key.

-rev

Reverse the order of the input buffer.

-sigfile file

Signature file (verify operation only).

-sign

Sign the input data and output the signed result. This requires a private key.

-verify

Verify the input data against the signature file and indicate if the verification succeeded or failed.

-verifyrecover

Verify the input data and output the recovered data.

PRIME

openssl prime [-bits n] [-checks n] [-generate] [-hex] [-safe] p

The prime command is used to generate prime numbers, or to check numbers for primality. Results are probabilistic: they have an exceedingly high likelihood of being correct, but are not guaranteed.

The options are as follows:

RAND

openssl rand: [-base64] [-hex] [-out file] num

The rand command outputs num pseudo-random bytes.

The options are as follows:

REQ

openssl req: [-addext ext] [-batch] [-config file] [-days n] [-extensions section] [-in file] [-inform der | pem] [-key keyfile] [-keyform der | pem] [-keyout file] [-md4 | -md5 | -sha1] [-modulus] [-multivalue-rdn] [-nameopt option] [-new] [-newhdr] [-newkey arg] [-nodes] [-noout] [-out file] [-outform der | pem] [-passin arg] [-passout arg] [-pkeyopt opt:value] [-pubkey] [-reqexts section] [-reqopt option] [-set_serial n] [-sigopt nm:v] [-subj arg] [-subject] [-text] [-utf8] [-verbose] [-verify] [-x509]

The req command primarily creates and processes certificate requests in PKCS#10 format. It can additionally create self-signed certificates, for use as root CAs, for example.

The options are as follows:

-addext ext: Add a specific extension to the certificate (if the -x509 option is present) or certificate request. The argument must have the form of a key=value pair as it would appear in a config file. This option can be given multiple times.
-batch: Non-interactive mode.
-config file: Specify an alternative configuration file.
-days n: Specify the number of days to certify the certificate for. The default is 30 days. Used with the -x509 option.
-extensions section, -reqexts section: Specify alternative sections to include certificate extensions (with -x509) or certificate request extensions, allowing several different sections to be used in the same configuration file.
-in file: The input file to read a request from, or standard input if not specified. A request is only read if the creation options -new and -newkey are not specified.
-inform der | pem: The input format.
-key keyfile: The file to read the private key from. It also accepts PKCS#8 format private keys for PEM format files.
-keyform der | pem: The format of the private key file specified in the -key argument. The default is pem.
-keyout file: The file to write the newly created private key to. If this option is not specified, the filename present in the configuration file is used.
-md5 | -sha1 | -sha256: The message digest to sign the request with. This overrides the digest algorithm specified in the configuration file.

Some public key algorithms may override this choice. For instance, DSA signatures always use SHA1.
-modulus: Print the value of the modulus of the public key contained in the request.
-multivalue-rdn: This option causes the -subj argument to be interpreted with full support for multivalued RDNs, for example “/DC=org/DC=OpenSSL/DC=users/UID=123456+CN=John Doe”. If -multivalue-rdn is not used, the UID value is set to “123456+CN=John Doe”.
-nameopt option, -reqopt option: Determine how the subject or issuer names are displayed. option can be a single option or multiple options separated by commas. Alternatively, these options may be used more than once to set multiple options. See the X509 section below for details.
-new: Generate a new certificate request. The user is prompted for the relevant field values. The actual fields prompted for and their maximum and minimum sizes are specified in the configuration file and any requested extensions.

If the -key option is not used, it will generate a new RSA private key using information specified in the configuration file.
-newhdr: Add the word NEW to the PEM file header and footer lines on the outputted request. Some software and CAs need this.
-newkey arg: Create a new certificate request and a new private key. The argument takes one of several forms.

rsa:nbits generates an RSA key nbits in size. If nbits is omitted, the default key size is used.

dsa:file generates a DSA key using the parameters in file.

param:file generates a key using the parameters or certificate in file.

All other algorithms support the form algorithm:file, where file may be an algorithm parameter file, created by the genpkey -genparam command or an X.509 certificate for a key with appropriate algorithm. file can be omitted, in which case any parameters can be specified via the -pkeyopt option.
-nodes: Do not encrypt the private key.
-noout: Do not output the encoded version of the request.
-out file: The output file to write to, or standard output if not specified.
-outform der | pem: The output format.
-passin arg: The key password source.
-passout arg: The output file password source.
-pkeyopt opt:value: Set the public key algorithm option opt to value.
-pubkey: Output the public key.
-reqopt option: Customise the output format used with -text. The option argument can be a single option or multiple options separated by commas. See also the discussion of -certopt in the x509 command.
-set_serial n: Serial number to use when outputting a self-signed certificate. This may be specified as a decimal value or a hex value if preceded by ‘0x’. It is possible to use negative serial numbers but this is not recommended.
-sigopt nm:v: Pass options to the signature algorithm during sign operation. The names and values of these options are algorithm-specific.
-subj arg: Replaces the subject field of an input request with the specified data and output the modified request. arg must be formatted as /type0=value0/type1=value1/type2=...; characters may be escaped by ‘\’ (backslash); no spaces are skipped.
-subject: Print the request subject (or certificate subject if -x509 is specified).
-text: Print the certificate request in plain text.
-utf8: Interpret field values as UTF8 strings, not ASCII.
-verbose: Print extra details about the operations being performed.
-verify: Verify the signature on the request.
-x509: Output a self-signed certificate instead of a certificate request. This is typically used to generate a test certificate or a self-signed root CA. The extensions added to the certificate (if any) are specified in the configuration file. Unless specified using the -set_serial option, 0 is used for the serial number.

The configuration options are specified in the “req” section of the configuration file. The options available are as follows:

attributes

The section containing any request attributes: its format is the same as distinguished_name. Typically these may contain the challengePassword or unstructuredName types. They are currently ignored by the openssl request signing utilities, but some CAs might want them.

default_bits

The default key size, in bits. The default is 2048. It is used if the -new option is used and can be overridden by using the -newkey option.

default_keyfile

The default file to write a private key to, or standard output if not specified. It can be overridden by the -keyout option.

default_md

The digest algorithm to use. Possible values include md5, sha1 and sha256 (the default). It can be overridden on the command line.

distinguished_name

The section containing the distinguished name fields to prompt for when generating a certificate or certificate request. The format is described below.

encrypt_key

If set to “no” and a private key is generated, it is not encrypted. It is equivalent to the -nodes option. For compatibility, encrypt_rsa_key is an equivalent option.

input_password | output_password

The passwords for the input private key file (if present) and the output private key file (if one will be created). The command line options -passin and -passout override the configuration file values.

oid_file

A file containing additional OBJECT IDENTIFIERS. Each line of the file should consist of the numerical form of the object identifier, followed by whitespace, then the short name followed by whitespace and finally the long name.

oid_section

Specify a section in the configuration file containing extra object identifiers. Each line should consist of the short name of the object identifier followed by ‘=’ and the numerical form. The short and long names are the same when this option is used.

prompt

If set to “no”, it disables prompting of certificate fields and just takes values from the config file directly. It also changes the expected format of the distinguished_name and attributes sections.

req_extensions

The configuration file section containing a list of extensions to add to the certificate request. It can be overridden by the -reqexts option.

string_mask

Limit the string types for encoding certain fields. The following values may be used, limiting strings to the indicated types:

utf8

If set to “yes”, field values are interpreted as UTF8 strings.

x509_extensions

The configuration file section containing a list of extensions to add to a certificate generated when the -x509 switch is used. It can be overridden by the -extensions command line switch.

There are two separate formats for the distinguished name and attribute sections. If the -prompt option is set to “no”, then these sections just consist of field names and values. If the -prompt option is absent or not set to “no”, then the file contains field prompting information of the form:

fieldName="prompt" 
fieldName_default="default field value" 
fieldName_min= 2 
fieldName_max= 4

“fieldName” is the field name being used, for example commonName (or CN). The “prompt” string is used to ask the user to enter the relevant details. If the user enters nothing, the default value is used; if no default value is present, the field is omitted. A field can still be omitted if a default value is present, if the user just enters the ‘.’ character.

The number of characters entered must be between the fieldName_min and fieldName_max limits: there may be additional restrictions based on the field being used (for example countryName can only ever be two characters long and must fit in a PrintableString).

Some fields (such as organizationName) can be used more than once in a DN. This presents a problem because configuration files will not recognize the same name occurring twice. To avoid this problem, if the fieldName contains some characters followed by a full stop, they will be ignored. So, for example, a second organizationName can be input by calling it “1.organizationName”.

The actual permitted field names are any object identifier short or long names. These are compiled into openssl and include the usual values such as commonName, countryName, localityName, organizationName, organizationalUnitName, stateOrProvinceName. Additionally, emailAddress is included as well as name, surname, givenName, initials and dnQualifier.

Additional object identifiers can be defined with the oid_file or oid_section options in the configuration file. Any additional fields will be treated as though they were a DirectoryString.

RSA

openssl rsa: [-aes128 | -aes192 | -aes256 | -des | -des3] [-check] [-in file] [-inform der | net | pem | pvk] [-modulus] [-noout] [-out file] [-outform der | net | pem | pvk] [-passin arg] [-passout arg] [-pubin] [-pubout] [-pvk-none | -pvk-strong | -pvk-weak] [-RSAPublicKey_in] [-RSAPublicKey_out] [-text]

The rsa command processes RSA keys. They can be converted between various forms and their components printed out. rsa uses the traditional SSLeay compatible format for private key encryption: newer applications should use the more secure PKCS#8 format using the pkcs8 utility.

The options are as follows:

RSAUTL

openssl rsautl: [-asn1parse] [-certin] [-decrypt] [-encrypt] [-hexdump] [-in file] [-inkey file] [-keyform der | pem] [-oaep | -pkcs | -raw | -x931] [-out file] [-passin arg] [-pubin] [-rev] [-sign] [-verify]

The rsautl command can be used to sign, verify, encrypt and decrypt data using the RSA algorithm.

The options are as follows:

S_CLIENT

openssl s_client: [-4 | -6] [-alpn protocols] [-bugs] [-CAfile file] [-CApath directory] [-cert file] [-certform der | pem] [-check_ss_sig] [-cipher cipherlist] [-connect host[:port]] [-crl_check] [-crl_check_all] [-crlf] [-debug] [-dtls] [-dtls1_2] [-extended_crl] [-groups list] [-host host] [-ign_eof] [-ignore_critical] [-issuer_checks] [-key keyfile] [-keyform der | pem] [-keymatexport label] [-keymatexportlen len] [-legacy_server_connect] [-msg] [-mtu mtu] [-nbio] [-nbio_test] [-no_comp] [-no_ign_eof] [-no_legacy_server_connect] [-no_ticket] [-no_tls1_2] [-no_tls1_3] [-pass arg] [-policy_check] [-port port] [-prexit] [-proxy host:port] [-quiet] [-reconnect] [-servername name] [-serverpref] [-sess_in file] [-sess_out file] [-showcerts] [-starttls protocol] [-state] [-status] [-timeout] [-tls1_2] [-tls1_3] [-tlsextdebug] [-use_srtp profiles] [-verify depth] [-verify_return_error] [-x509_strict] [-xmpphost host]

The s_client command implements a generic SSL/TLS client which connects to a remote host using SSL/TLS.

If a connection is established with an SSL server, any data received from the server is displayed and any key presses will be sent to the server. When used interactively (which means neither -quiet nor -ign_eof have been given), the session will be renegotiated if the line begins with an R; if the line begins with a Q or if end of file is reached, the connection will be closed down.

The options are as follows:

-4: Attempt connections using IPv4 only.
-6: Attempt connections using IPv6 only.
-alpn protocols: Enable the Application-Layer Protocol Negotiation. protocols is a comma-separated list of protocol names that the client should advertise support for.
-bugs: Enable various workarounds for buggy implementations.
-CAfile file: A file containing trusted certificates to use during server authentication and to use when attempting to build the client certificate chain.
-CApath directory: The directory to use for server certificate verification. This directory must be in “hash format”; see -verify for more information. These are also used when building the client certificate chain.
-cert file: The certificate to use, if one is requested by the server. The default is not to use a certificate.
-certform der | pem: The certificate format. The default is pem.
-check_ss_sig, -crl_check, -crl_check_all, -extended_crl, -ignore_critical, -issuer_checks, -policy_check, -x509_strict: Set various certificate chain validation options. See the verify command for details.
-cipher cipherlist: Modify the cipher list sent by the client. Although the server determines which cipher suite is used, it should take the first supported cipher in the list sent by the client. See the ciphers command for more information.
-connect host[:port]: The host and port to connect to. If not specified, an attempt is made to connect to the local host on port 4433. Alternatively, the host and port pair may be separated using a forward-slash character, which is useful for numeric IPv6 addresses.
-crlf: Translate a line feed from the terminal into CR+LF, as required by some servers.
-debug: Print extensive debugging information, including a hex dump of all traffic.
-dtls: Permit any version of DTLS.
-dtls1_2: Permit only DTLS1.2.
-groups list: Set the supported elliptic curve groups to the colon separated list of group NIDs or names as documented in SSL_CTX_set1_groups_list(3).
-host host: The host to connect to. The default is localhost.
-ign_eof: Inhibit shutting down the connection when end of file is reached in the input.
-key keyfile: The private key to use. If not specified, the certificate file will be used.
-keyform der | pem: The private key format. The default is pem.
-keymatexport label: Export keying material using label.
-keymatexportlen len: Export len bytes of keying material (default 20).
-legacy_server_connect, -no_legacy_server_connect: Allow or disallow initial connection to servers that don't support RI.
-msg: Show all protocol messages with hex dump.
-mtu mtu: Set the link layer MTU.
-nbio: Turn on non-blocking I/O.
-nbio_test: Test non-blocking I/O.
-no_ign_eof: Shut down the connection when end of file is reached in the input. Can be used to override the implicit -ign_eof after -quiet.
-no_tls1_2 | -no_tls1_3: Disable the use of TLS1.2 and 1.3, respectively.
-no_ticket: Disable RFC 4507 session ticket support.
-pass arg: The private key password source.
-port port: The port to connect to. The default is 4433.
-prexit: Print session information when the program exits. This will always attempt to print out information even if the connection fails. Normally, information will only be printed out once if the connection succeeds. This option is useful because the cipher in use may be renegotiated or the connection may fail because a client certificate is required or is requested only after an attempt is made to access a certain URL. Note that the output produced by this option is not always accurate because a connection might never have been established.
-proxy host:port: Use the HTTP proxy at host and port. The connection to the proxy is done in cleartext and the -connect argument is given to the proxy. If not specified, localhost is used as final destination. After that, switch the connection through the proxy to the destination to TLS.
-quiet: Inhibit printing of session and certificate information. This implicitly turns on -ign_eof as well.
-reconnect: Reconnect to the same server 5 times using the same session ID; this can be used as a test that session caching is working.
-servername name: Include the TLS Server Name Indication (SNI) extension in the ClientHello message, using the specified server name.
-showcerts: Display the whole server certificate chain: normally only the server certificate itself is displayed.
-serverpref: Use the server's cipher preferences.
-sess_in file: Load TLS session from file. The client will attempt to resume a connection from this session.
-sess_out file: Output TLS session to file.
-starttls protocol: Send the protocol-specific messages to switch to TLS for communication. protocol is a keyword for the intended protocol. Currently, the supported keywords are “ftp”, “imap”, “smtp”, “pop3”, and “xmpp”.
-state: Print the SSL session states.
-status: Send a certificate status request to the server (OCSP stapling). The server response (if any) is printed out.
-timeout: Enable send/receive timeout on DTLS connections.
-tls1_2 | -tls1_3: Permit only TLS1.2 or 1.3 respectively.
-tlsextdebug: Print a hex dump of any TLS extensions received from the server.
-use_srtp profiles: Offer SRTP key management with a colon-separated profile list.
-verify depth: Turn on server certificate verification, with a maximum length of depth. Currently the verify operation continues after errors so all the problems with a certificate chain can be seen. As a side effect the connection will never fail due to a server certificate verify failure.
-verify_return_error: Return verification error.
-xmpphost hostname: When used with -starttls xmpp, specify the host for the "to" attribute of the stream element. If this option is not specified then the host specified with -connect will be used.

S_SERVER

openssl s_server: [-accept port] [-alpn protocols] [-bugs] [-CAfile file] [-CApath directory] [-cert file] [-cert2 file] [-certform der | pem] [-cipher cipherlist] [-context id] [-crl_check] [-crl_check_all] [-crlf] [-dcert file] [-dcertform der | pem] [-debug] [-dhparam file] [-dkey file] [-dkeyform der | pem] [-dpass arg] [-dtls] [-dtls1] [-dtls1_2] [-groups list] [-HTTP] [-id_prefix arg] [-key keyfile] [-key2 keyfile] [-keyform der | pem] [-keymatexport label] [-keymatexportlen len] [-msg] [-mtu mtu] [-naccept num] [-named_curve arg] [-nbio] [-nbio_test] [-no_cache] [-no_dhe] [-no_ecdhe] [-no_ticket] [-no_tls1_2] [-no_tls1_3] [-no_tmp_rsa] [-nocert] [-pass arg] [-quiet] [-servername name] [-servername_fatal] [-serverpref] [-state] [-status] [-status_timeout nsec] [-status_url url] [-status_verbose] [-timeout] [-tls1_2] [-tls1_3] [-tlsextdebug] [-use_srtp profiles] [-Verify depth] [-verify depth] [-verify_return_error] [-WWW] [-www]

The s_server command implements a generic SSL/TLS server which listens for connections on a given port using SSL/TLS.

If a connection request is established with a client and neither the -www nor the -WWW option has been used, then any data received from the client is displayed and any key presses are sent to the client. Certain single letter commands perform special operations:

The options are as follows:

-accept port: Listen on TCP port for connections. The default is port 4433.
-alpn protocols: Enable the Application-Layer Protocol Negotiation. protocols is a comma-separated list of supported protocol names.
-bugs: Enable various workarounds for buggy implementations.
-CAfile file: A file containing trusted certificates to use during client authentication and to use when attempting to build the server certificate chain. The list is also used in the list of acceptable client CAs passed to the client when a certificate is requested.
-CApath directory: The directory to use for client certificate verification. This directory must be in “hash format”; see -verify for more information. These are also used when building the server certificate chain.
-cert file: The certificate to use: most server's cipher suites require the use of a certificate and some require a certificate with a certain public key type. For example, the DSS cipher suites require a certificate containing a DSS (DSA) key. If not specified, the file server.pem will be used.
-cert2 file: The certificate to use for servername.
-certform der | pem: The certificate format. The default is pem.
-cipher cipherlist: Modify the cipher list used by the server. This allows the cipher list used by the server to be modified. When the client sends a list of supported ciphers, the first client cipher also included in the server list is used. Because the client specifies the preference order, the order of the server cipherlist is irrelevant. See the ciphers command for more information.
-context id: Set the SSL context ID. It can be given any string value.
-crl_check, -crl_check_all: Check the peer certificate has not been revoked by its CA. The CRLs are appended to the certificate file. -crl_check_all checks all CRLs of all CAs in the chain.
-crlf: Translate a line feed from the terminal into CR+LF.
-dcert file, -dkey file: Specify an additional certificate and private key; these behave in the same manner as the -cert and -key options except there is no default if they are not specified (no additional certificate or key is used). By using RSA and DSS certificates and keys, a server can support clients which only support RSA or DSS cipher suites by using an appropriate certificate.
-dcertform der | pem, -dkeyform der | pem, -dpass arg: Additional certificate and private key format, and private key password source, respectively.
-debug: Print extensive debugging information, including a hex dump of all traffic.
-dhparam file: The DH parameter file to use. The ephemeral DH cipher suites generate keys using a set of DH parameters. If not specified, an attempt is made to load the parameters from the server certificate file. If this fails, a static set of parameters hard coded into the s_server program will be used.
-dtls: Permit any version of DTLS.
-dtls1_2: Permit only DTLS1.2.
-groups list: Set the supported elliptic curve groups to the colon separated list of group NIDs or names as documented in SSL_CTX_set1_groups_list(3).
-HTTP: Emulate a simple web server. Pages are resolved relative to the current directory. For example if the URL https://myhost/page.html is requested, the file ./page.html will be loaded. The files loaded are assumed to contain a complete and correct HTTP response (lines that are part of the HTTP response line and headers must end with CRLF).
-id_prefix arg: Generate SSL/TLS session IDs prefixed by arg. This is mostly useful for testing any SSL/TLS code that wish to deal with multiple servers, when each of which might be generating a unique range of session IDs.
-key keyfile: The private key to use. If not specified, the certificate file will be used.
-key2 keyfile: The private key to use for servername.
-keyform der | pem: The private key format. The default is pem.
-keymatexport label: Export keying material using label.
-keymatexportlen len: Export len bytes of keying material (default 20).
-msg: Show all protocol messages with hex dump.
-mtu mtu: Set the link layer MTU.
-naccept num: Terminate server after num connections.
-named_curve arg: Specify the elliptic curve name to use for ephemeral ECDH keys. This option is deprecated; use -groups instead.
-nbio: Turn on non-blocking I/O.
-nbio_test: Test non-blocking I/O.
-no_cache: Disable session caching.
-no_dhe: Disable ephemeral DH cipher suites.
-no_ecdhe: Disable ephemeral ECDH cipher suites.
-no_ticket: Disable RFC 4507 session ticket support.
-no_tls1_2 | -no_tls1_3: Disable the use of TLS1.2 and 1.3, respectively.
-no_tmp_rsa: Disable temporary RSA key generation.
-nocert: Do not use a certificate. This restricts the cipher suites available to the anonymous ones (currently just anonymous DH).
-pass arg: The private key password source.
-quiet: Inhibit printing of session and certificate information.
-servername name: Set the TLS Server Name Indication (SNI) extension with name.
-servername_fatal: Send fatal alert if servername does not match. The default is warning alert.
-serverpref: Use server's cipher preferences.
-state: Print the SSL session states.
-status: Enables certificate status request support (OCSP stapling).
-status_timeout nsec: Sets the timeout for OCSP response in seconds.
-status_url url: Sets a fallback responder URL to use if no responder URL is present in the server certificate. Without this option, an error is returned if the server certificate does not contain a responder address.
-status_verbose: Enables certificate status request support (OCSP stapling) and gives a verbose printout of the OCSP response.
-timeout: Enable send/receive timeout on DTLS connections.
-tls1_2 | -tls1_3: Permit only TLS1.2, or 1.3, respectively.
-tlsextdebug: Print a hex dump of any TLS extensions received from the server.
-use_srtp profiles: Offer SRTP key management with a colon-separated profile list.
-verify_return_error: Return verification error.
-WWW: Emulate a simple web server. Pages are resolved relative to the current directory. For example if the URL https://myhost/page.html is requested, the file ./page.html will be loaded.
-www: Send a status message to the client when it connects, including information about the ciphers used and various session parameters. The output is in HTML format so this option will normally be used with a web browser.
-Verify depth, -verify depth: Request a certificate chain from the client, with a maximum length of depth. With -Verify, the client must supply a certificate or an error occurs; with -verify, a certificate is requested but the client does not have to send one.

S_TIME

openssl s_time: [-bugs] [-CAfile file] [-CApath directory] [-cert file] [-cipher cipherlist] [-connect host[:port]] [-key keyfile] [-nbio] [-new] [-no_shutdown] [-reuse] [-time seconds] [-verify depth] [-www page]

The s_time command implements a generic SSL/TLS client which connects to a remote host using SSL/TLS. It can request a page from the server and includes the time to transfer the payload data in its timing measurements. It measures the number of connections within a given timeframe, the amount of data transferred (if any), and calculates the average time spent for one connection.

The options are as follows:

SESS_ID

openssl sess_id: [-cert] [-context ID] [-in file] [-inform der | pem] [-noout] [-out file] [-outform der | pem] [-text]

The sess_id program processes the encoded version of the SSL session structure and optionally prints out SSL session details (for example the SSL session master key) in human-readable format.

The options are as follows:

The output of sess_id is composed as follows:

Since the SSL session output contains the master key, it is possible to read the contents of an encrypted session using this information. Therefore appropriate security precautions should be taken if the information is being output by a “real” application. This is, however, strongly discouraged and should only be used for debugging purposes.

SMIME

openssl smime: [-aes128 | -aes192 | -aes256 | -des | -des3 | -rc2-40 | -rc2-64 | -rc2-128] [-binary] [-CAfile file] [-CApath directory] [-certfile file] [-check_ss_sig] [-content file] [-crl_check] [-crl_check_all] [-decrypt] [-encrypt] [-extended_crl] [-from addr] [-ignore_critical] [-in file] [-indef] [-inform der | pem | smime] [-inkey file] [-issuer_checks] [-keyform der | pem] [-md digest] [-noattr] [-nocerts] [-nochain] [-nodetach] [-noindef] [-nointern] [-nosigs] [-nosmimecap] [-noverify] [-out file] [-outform der | pem | smime] [-passin arg] [-pk7out] [-policy_check] [-recip file] [-resign] [-sign] [-signer file] [-stream] [-subject s] [-text] [-to addr] [-verify] [-x509_strict] [cert.pem ...]

The smime command handles S/MIME mail. It can encrypt, decrypt, sign, and verify S/MIME messages.

The MIME message must be sent without any blank lines between the headers and the output. Some mail programs will automatically add a blank line. Piping the mail directly to an MTA is one way to achieve the correct format.

The supplied message to be signed or encrypted must include the necessary MIME headers or many S/MIME clients won't display it properly (if at all). Use the -text option to automatically add plain text headers.

A “signed and encrypted” message is one where a signed message is then encrypted. This can be produced by encrypting an already signed message.

There are a number of operations that can be performed, as follows:

The remaining options are as follows:

-aes128 | -aes192 | -aes256 | -des | -des3 | -rc2-40 | -rc2-64 | -rc2-128: The encryption algorithm to use. 128-, 192-, or 256-bit AES, DES (56 bits), triple DES (168 bits), or 40-, 64-, or 128-bit RC2, respectively; if not specified, 40-bit RC2 is used. Only used with -encrypt.
-binary: Normally, the input message is converted to “canonical” format which uses CR/LF as end of line, as required by the S/MIME specification. When this option is present, no translation occurs. This is useful when handling binary data which may not be in MIME format.
-CAfile file: A file containing trusted CA certificates; only used with -verify.
-CApath directory: A directory containing trusted CA certificates; only used with -verify. This directory must be a standard certificate directory: that is, a hash of each subject name (using x509 -hash) should be linked to each certificate.
cert.pem ...: One or more certificates of message recipients: used when encrypting a message.
-certfile file: Allows additional certificates to be specified. When signing, these will be included with the message. When verifying, these will be searched for the signers' certificates. The certificates should be in PEM format.
-check_ss_sig, -crl_check, -crl_check_all, -extended_crl, -ignore_critical, -issuer_checks, -policy_check, -x509_strict: Set various certificate chain validation options. See the verify command for details.
-content file: A file containing the detached content. This is only useful with the -verify option, and only usable if the PKCS#7 structure is using the detached signature form where the content is not included. This option will override any content if the input format is S/MIME and it uses the multipart/signed MIME content type.
-from addr, -subject s, -to addr: The relevant mail headers. These are included outside the signed portion of a message so they may be included manually. When signing, many S/MIME mail clients check that the signer's certificate email address matches the From: address.
-in file: The input file to read from.
-indef: Enable streaming I/O for encoding operations. This permits single pass processing of data without the need to hold the entire contents in memory, potentially supporting very large files. Streaming is automatically set for S/MIME signing with detached data if the output format is SMIME; it is currently off by default for all other operations.
-inform der | pem | smime: The input format.
-inkey file: The private key to use when signing or decrypting, which must match the corresponding certificate. If this option is not specified, the private key must be included in the certificate file specified with the -recip or -signer file. When signing, this option can be used multiple times to specify successive keys.
-keyform der | pem: Input private key format. The default is pem.
-md digest: The digest algorithm to use when signing or resigning. If not present then the default digest algorithm for the signing key is used (usually SHA1).
-noattr: Do not include attributes.
-nocerts: Do not include the signer's certificate. This will reduce the size of the signed message but the verifier must have a copy of the signer's certificate available locally (passed using the -certfile option, for example).
-nochain: Do not do chain verification of signers' certificates: that is, don't use the certificates in the signed message as untrusted CAs.
-nodetach: When signing a message, use opaque signing: this form is more resistant to translation by mail relays but it cannot be read by mail agents that do not support S/MIME. Without this option cleartext signing with the MIME type multipart/signed is used.
-noindef: Disable streaming I/O where it would produce an encoding of indefinite length (currently has no effect).
-nointern: Only use certificates specified in the -certfile. The supplied certificates can still be used as untrusted CAs.
-nosigs: Do not try to verify the signatures on the message.
-nosmimecap: Exclude the list of supported algorithms from signed attributes, other options such as signing time and content type are still included.
-noverify: Do not verify the signer's certificate of a signed message.
-out file: The output file to write to.
-outform der | pem | smime: The output format. The default is smime, which writes an S/MIME format message. pem and der change this to write PEM and DER format PKCS#7 structures instead. This currently only affects the output format of the PKCS#7 structure; if no PKCS#7 structure is being output (for example with -verify or -decrypt) this option has no effect.
-passin arg: The key password source.
-recip file: The recipients certificate when decrypting a message. This certificate must match one of the recipients of the message or an error occurs.
-signer file: A signing certificate when signing or resigning a message; this option can be used multiple times if more than one signer is required. If a message is being verified, the signer's certificates will be written to this file if the verification was successful.
-stream: The same as -indef.
-text: Add plain text (text/plain) MIME headers to the supplied message if encrypting or signing. If decrypting or verifying, it strips off text headers: if the decrypted or verified message is not of MIME type text/plain then an error occurs.

The exit codes for smime are as follows:

SPEED

openssl speed: [algorithm] [-decrypt] [-elapsed] [-evp algorithm] [-mr] [-multi number] [-unaligned number]

The speed command is used to test the performance of cryptographic algorithms.

TS

openssl ts: -query [-md4 | -md5 | -ripemd160 | -sha1] [-cert] [-config configfile] [-data file_to_hash] [-digest digest_bytes] [-in request.tsq] [-no_nonce] [-out request.tsq] [-policy object_id] [-text]
openssl ts: -reply [-chain certs_file.pem] [-config configfile] [-in response.tsr] [-inkey private.pem] [-out response.tsr] [-passin arg] [-policy object_id] [-queryfile request.tsq] [-section tsa_section] [-signer tsa_cert.pem] [-text] [-token_in] [-token_out]
openssl ts: -verify [-CAfile trusted_certs.pem] [-CApath trusted_cert_path] [-data file_to_hash] [-digest digest_bytes] [-in response.tsr] [-queryfile request.tsq] [-token_in] [-untrusted cert_file.pem]

The ts command is a basic Time Stamping Authority (TSA) client and server application as specified in RFC 3161 (Time-Stamp Protocol, TSP). A TSA can be part of a PKI deployment and its role is to provide long term proof of the existence of specific data. Here is a brief description of the protocol:

The TSA client computes a one-way hash value for a data file and sends the hash to the TSA.
The TSA attaches the current date and time to the received hash value, signs them and sends the time stamp token back to the client. By creating this token the TSA certifies the existence of the original data file at the time of response generation.
The TSA client receives the time stamp token and verifies the signature on it. It also checks if the token contains the same hash value that it had sent to the TSA.

There is one DER-encoded protocol data unit defined for transporting a time stamp request to the TSA and one for sending the time stamp response back to the client. The ts command has three main functions: creating a time stamp request based on a data file; creating a time stamp response based on a request; and verifying if a response corresponds to a particular request or a data file.

There is no support for sending the requests/responses automatically over HTTP or TCP yet as suggested in RFC 3161. Users must send the requests either by FTP or email.

The -query switch can be used for creating and printing a time stamp request with the following options:

A time stamp response (TimeStampResp) consists of a response status and the time stamp token itself (ContentInfo), if the token generation was successful. The -reply command is for creating a time stamp response or time stamp token based on a request and printing the response/token in human-readable format. If -token_out is not specified the output is always a time stamp response (TimeStampResp), otherwise it is a time stamp token (ContentInfo).

The -verify command is for verifying if a time stamp response or time stamp token is valid and matches a particular time stamp request or data file. The -verify command does not use the configuration file.

Options specified on the command line always override the settings in the config file:

tsa section, default_tsa: This is the main section and it specifies the name of another section that contains all the options for the -reply option. This section can be overridden with the -section command line switch.
oid_file: See ca for a description.
oid_section: See ca for a description.
serial: The file containing the hexadecimal serial number of the last time stamp response created. This number is incremented by 1 for each response. If the file does not exist at the time of response generation, a new file is created with serial number 1. This parameter is mandatory.
signer_cert: TSA signing certificate, in PEM format. The same as the -signer command line option.
certs: A set of PEM-encoded certificates that need to be included in the response. The same as the -chain command line option.
signer_key: The private key of the TSA, in PEM format. The same as the -inkey command line option.
default_policy: The default policy to use when the request does not mandate any policy. The same as the -policy command line option.
other_policies: Comma separated list of policies that are also acceptable by the TSA and used only if the request explicitly specifies one of them.
digests: The list of message digest algorithms that the TSA accepts. At least one algorithm must be specified. This parameter is mandatory.
accuracy: The accuracy of the time source of the TSA in seconds, milliseconds and microseconds. For example, secs:1, millisecs:500, microsecs:100. If any of the components is missing, zero is assumed for that field.
clock_precision_digits: The maximum number of digits, which represent the fraction of seconds, that need to be included in the time field. The trailing zeroes must be removed from the time, so there might actually be fewer digits or no fraction of seconds at all. The maximum value is 6; the default is 0.
ordering: If this option is yes, the responses generated by this TSA can always be ordered, even if the time difference between two responses is less than the sum of their accuracies. The default is no.
tsa_name: Set this option to yes if the subject name of the TSA must be included in the TSA name field of the response. The default is no.
ess_cert_id_chain: The SignedData objects created by the TSA always contain the certificate identifier of the signing certificate in a signed attribute (see RFC 2634, Enhanced Security Services). If this option is set to yes and either the certs variable or the -chain option is specified then the certificate identifiers of the chain will also be included in the SigningCertificate signed attribute. If this variable is set to no, only the signing certificate identifier is included. The default is no.

VERIFY

openssl verify: [-CAfile file] [-CApath directory] [-check_ss_sig] [-CRLfile file] [-crl_check] [-crl_check_all] [-explicit_policy] [-extended_crl] [-help] [-ignore_critical] [-inhibit_any] [-inhibit_map] [-issuer_checks] [-legacy_verify] [-policy_check] [-purpose purpose] [-trusted file] [-untrusted file] [-verbose] [-x509_strict] [certificates]

The verify command verifies certificate chains.

The options are as follows:

-CAfile file: A file of trusted certificates. The file should contain multiple certificates in PEM format, concatenated together.
-CApath directory: A directory of trusted certificates. The certificates, or symbolic links to them, should have names of the form hash.0, where hash is the hashed certificate subject name (see the -hash option of the x509 utility).
-check_ss_sig: Verify the signature on the self-signed root CA. This is disabled by default because it doesn't add any security.
-CRLfile file: The file should contain one or more CRLs in PEM format.
-crl_check: Check end entity certificate validity by attempting to look up a valid CRL. If a valid CRL cannot be found, an error occurs.
-crl_check_all: Check the validity of all certificates in the chain by attempting to look up valid CRLs.
-explicit_policy: Set policy variable require-explicit-policy (RFC 3280).
-extended_crl: Enable extended CRL features such as indirect CRLs and alternate CRL signing keys.
-help: Print a usage message.
-ignore_critical: Ignore critical extensions instead of rejecting the certificate.
-inhibit_any: Set policy variable inhibit-any-policy (RFC 3280).
-inhibit_map: Set policy variable inhibit-policy-mapping (RFC 3280).
-issuer_checks: Print diagnostics relating to searches for the issuer certificate of the current certificate showing why each candidate issuer certificate was rejected. The presence of rejection messages does not itself imply that anything is wrong: during the normal verify process several rejections may take place.
-legacy_verify: Use the legacy X.509 certificate chain verification code.
-policy_check: Enable certificate policy processing.
-purpose purpose: The intended use for the certificate. Without this option no chain verification will be done. Currently accepted uses are sslclient, sslserver, nssslserver, smimesign, smimeencrypt, crlsign, any, and ocsphelper.
-trusted file: A file of trusted certificates. The file should contain multiple certificates.
-untrusted file: A file of untrusted certificates. The file should contain multiple certificates.
-verbose: Print extra information about the operations being performed.
-x509_strict: Disable workarounds for broken certificates which have to be disabled for strict X.509 compliance.
certificates: One or more PEM certificates to verify. If no certificate files are included, an attempt is made to read a certificate from standard input. If the first certificate filename begins with a dash, use a lone dash to mark the last option.

The verify program uses the same functions as the internal SSL and S/MIME verification, with one crucial difference: wherever possible an attempt is made to continue after an error, whereas normally the verify operation would halt on the first error. This allows all the problems with a certificate chain to be determined.

The verify operation consists of a number of separate steps. Firstly a certificate chain is built up starting from the supplied certificate and ending in the root CA. It is an error if the whole chain cannot be built up. The chain is built up by looking up the issuer's certificate of the current certificate. If a certificate is found which is its own issuer, it is assumed to be the root CA.

All certificates whose subject name matches the issuer name of the current certificate are subject to further tests. The relevant authority key identifier components of the current certificate (if present) must match the subject key identifier (if present) and issuer and serial number of the candidate issuer; in addition the keyUsage extension of the candidate issuer (if present) must permit certificate signing.

The lookup first looks in the list of untrusted certificates and if no match is found the remaining lookups are from the trusted certificates. The root CA is always looked up in the trusted certificate list: if the certificate to verify is a root certificate, then an exact match must be found in the trusted list.

The second operation is to check every untrusted certificate's extensions for consistency with the supplied purpose. If the -purpose option is not included, then no checks are done. The supplied or “leaf” certificate must have extensions compatible with the supplied purpose and all other certificates must also be valid CA certificates. The precise extensions required are described in more detail in the X509 section below.

The third operation is to check the trust settings on the root CA. The root CA should be trusted for the supplied purpose. A certificate with no trust settings is considered to be valid for all purposes.

The final operation is to check the validity of the certificate chain. The validity period is checked against the current system time and the notBefore and notAfter dates in the certificate. The certificate signatures are also checked at this point.

If all operations complete successfully, the certificate is considered valid. If any operation fails then the certificate is not valid. When a verify operation fails, the output messages can be somewhat cryptic. The general form of the error message is:

server.pem: /C=AU/ST=Queensland/O=CryptSoft Pty Ltd/CN=Test CA (1024-bit) 
error 24 at 1 depth lookup:invalid CA certificate

The first line contains the name of the certificate being verified, followed by the subject name of the certificate. The second line contains the error number as defined by the X509_V_ERR_* constants in <openssl/x509_vfy.h>, the associated error message documented in X509_STORE_CTX_get_error(3), and the depth. The depth is the number of the certificate being verified when a problem was detected starting with zero for the certificate being verified itself, then 1 for the CA that signed the certificate and so on.

VERSION

openssl version [-abdfpv]

The version command is used to print out version information about openssl.

The options are as follows:

X509

openssl x509: [-C] [-addreject arg] [-addtrust arg] [-alias] [-CA file] [-CAcreateserial] [-CAform der | pem] [-CAkey file] [-CAkeyform der | pem] [-CAserial file] [-certopt option] [-checkend arg] [-clrext] [-clrreject] [-clrtrust] [-dates] [-days arg] [-email] [-enddate] [-extensions section] [-extfile file] [-fingerprint] [-force_pubkey key] [-hash] [-in file] [-inform der | net | pem] [-issuer] [-issuer_hash] [-issuer_hash_old] [-keyform der | pem] [-md5 | -sha1] [-modulus] [-multivalue-rdn] [-nameopt option] [-new] [-next_serial] [-noout] [-ocsp_uri] [-ocspid] [-out file] [-outform der | net | pem] [-passin arg] [-pubkey] [-purpose] [-req] [-serial] [-set_issuer name] [-set_serial n] [-set_subject name] [-setalias arg] [-signkey file] [-sigopt nm:v] [-startdate] [-subject] [-subject_hash] [-subject_hash_old] [-text] [-trustout] [-utf8] [-x509toreq]

The x509 command is a multi-purpose certificate utility. It can be used to display certificate information, convert certificates to various forms, sign certificate requests like a “mini CA”, or edit certificate trust settings.

The following are x509 input, output, and general purpose options:

The following are x509 display options:

-C

Output the certificate in the form of a C source file.

-certopt option

Customise the output format used with -text, either using a list of comma-separated options or by specifying -certopt multiple times. The default behaviour is to print all fields. The options are as follows:

-dates

Print the start and expiry date of a certificate.

-email

Output the email addresses, if any.

-enddate

Print the expiry date of the certificate; that is, the notAfter date.

-fingerprint

Print the digest of the DER-encoded version of the whole certificate.

-hash

A synonym for -subject_hash.

-issuer

Print the issuer name.

-issuer_hash

Print the hash of the certificate issuer name.

-issuer_hash_old

Print the hash of the certificate issuer name using the older algorithm as used by openssl versions before 1.0.0.

-modulus

Print the value of the modulus of the public key contained in the certificate.

-multivalue-rdn

This option causes the -subj argument to be interpreted with full support for multivalued RDNs, for example “/DC=org/DC=OpenSSL/DC=users/UID=123456+CN=John Doe”. If -multivalue-rdn is not used, the UID value is set to “123456+CN=John Doe”.

-nameopt option

Customise how the subject or issuer names are displayed, either using a list of comma-separated options or by specifying -nameopt multiple times. The default behaviour is to use the oneline format. The options, which can be preceded by a dash to turn them off, are as follows:

align: Align field values for a more readable output. Only usable with sep_multiline.
compat: Use the old format, equivalent to specifying no options at all.
dn_rev: Reverse the fields of the DN, as required by RFC 2253. As a side effect, this also reverses the order of multiple AVAs.
dump_all: Dump all fields. When used with dump_der, it allows the DER encoding of the structure to be unambiguously determined.
dump_der: Any fields that need to be hexdumped are dumped using the DER encoding of the field. Otherwise just the content octets will be displayed. Both options use the RFC 2253 #XXXX... format.
dump_nostr: Dump non-character string types (for example OCTET STRING); usually, non-character string types are displayed as though each content octet represents a single character.
dump_unknown: Dump any field whose OID is not recognised by openssl.
esc_2253: Escape the “special” characters required by RFC 2253 in a field that is “ ,+"<>;”. Additionally, ‘#’ is escaped at the beginning of a string and a space character at the beginning or end of a string.
esc_ctrl: Escape control characters. That is, those with ASCII values less than 0x20 (space) and the delete (0x7f) character. They are escaped using the RFC 2253 \XX notation (where XX are two hex digits representing the character value).
esc_msb: Escape characters with the MSB set; that is, with ASCII values larger than 127.
multiline: A multiline format. Equivalent to esc_ctrl, esc_msb, sep_multiline, space_eq, lname, and align.
no_type: Do not attempt to interpret multibyte characters. That is, content octets are merely dumped as though one octet represents each character. This is useful for diagnostic purposes but results in rather odd looking output.
nofname, sname, lname, oid: Alter how the field name is displayed: nofname does not display the field at all; sname uses the short name form (CN for commonName, for example); lname uses the long form. oid represents the OID in numerical form and is useful for diagnostic purpose.
oneline: A one line format which is more readable than RFC2253. Equivalent to esc_2253, esc_ctrl, esc_msb, utf8, dump_nostr, dump_der, use_quote, sep_comma_plus_spc, space_eq, and sname.
RFC2253: Displays names compatible with RFC 2253. Equivalent to esc_2253, esc_ctrl, esc_msb, utf8, dump_nostr, dump_unknown, dump_der, sep_comma_plus, dn_rev, and sname.
sep_comma_plus, sep_comma_plus_space, sep_semi_plus_space, sep_multiline: Determine the field separators: the first character is between RDNs and the second between multiple AVAs (multiple AVAs are very rare and their use is discouraged). The options ending in “space” additionally place a space after the separator to make it more readable. sep_multiline uses a linefeed character for the RDN separator and a spaced ‘+’ for the AVA separator, as well as indenting the fields by four characters. If no field separator is specified then sep_comma_plus_space is used by default.
show_type: Show the type of the ASN.1 character string. The type precedes the field contents. For example “BMPSTRING: Hello World”.
space_eq: Place spaces round the ‘=’ character which follows the field name.
use_quote: Escape some characters by surrounding the whole string with ‘"’ characters. Without the option, all escaping is done with the ‘\’ character.
utf8: Convert all strings to UTF8 format first, as required by RFC 2253. On a UTF8 compatible terminal, the use of this option (and not setting esc_msb) may result in the correct display of multibyte characters. Usually, multibyte characters larger than 0xff are represented using the format \UXXXX for 16 bits and \WXXXXXXXX for 32 bits, and any UTF8Strings are converted to their character form first.

-next_serial

Print the next serial number.

-noout

Do not output the encoded version of the request.

-ocsp_uri

Print the OCSP responder addresses, if any.

-ocspid

Print OCSP hash values for the subject name and public key.

-pubkey

Print the public key.

-serial

Print the certificate serial number.

-sigopt nm:v

Pass options to the signature algorithm during sign or certify operations. The names and values of these options are algorithm-specific.

-startdate

Print the start date of the certificate; that is, the notBefore date.

-subject

Print the subject name.

-subject_hash

Print the hash of the certificate subject name. This is used in openssl to form an index to allow certificates in a directory to be looked up by subject name.

-subject_hash_old

Print the hash of the certificate subject name using the older algorithm as used by openssl versions before 1.0.0.

-text

Print the full certificate in text form.

A trusted certificate is a certificate which has several additional pieces of information attached to it such as the permitted and prohibited uses of the certificate and an alias. When a certificate is being verified, at least one certificate must be trusted. By default, a trusted certificate must be stored locally and be a root CA. The following are x509 trust settings options:

-addreject arg

Add a prohibited use. Accepts the same values as the -addtrust option.

-addtrust arg

Add a trusted certificate use. Any object name can be used here, but currently only clientAuth (SSL client use), serverAuth (SSL server use), and emailProtection (S/MIME email) are used.

-alias

Output the certificate alias.

-clrreject

Clear all the prohibited or rejected uses of the certificate.

-clrtrust

Clear all the permitted or trusted uses of the certificate.

-purpose

Perform tests on the certificate extensions. The same code is used when verifying untrusted certificates in chains, so this section is useful if a chain is rejected by the verify code.

The basicConstraints extension CA flag is used to determine whether the certificate can be used as a CA. If the CA flag is true, it is a CA; if the CA flag is false, it is not a CA. All CAs should have the CA flag set to true.

If the basicConstraints extension is absent, then the certificate is considered to be a possible CA; other extensions are checked according to the intended use of the certificate. A warning is given in this case because the certificate should really not be regarded as a CA. However it is allowed to be a CA to work around some broken software.

If the certificate is a V1 certificate (and thus has no extensions) and it is self-signed, it is also assumed to be a CA but a warning is again given. This is to work around the problem of Verisign roots which are V1 self-signed certificates.

If the keyUsage extension is present, then additional restraints are made on the uses of the certificate. A CA certificate must have the keyCertSign bit set if the keyUsage extension is present.

The extended key usage extension places additional restrictions on the certificate uses. If this extension is present, whether critical or not, the key can only be used for the purposes specified.

A complete description of each test is given below. The comments about basicConstraints and keyUsage and V1 certificates above apply to all CA certificates.

SSL Client: The extended key usage extension must be absent or include the web client authentication OID. keyUsage must be absent or it must have the digitalSignature bit set. The Netscape certificate type must be absent or it must have the SSL client bit set.
SSL Client CA: The extended key usage extension must be absent or include the web client authentication OID. The Netscape certificate type must be absent or it must have the SSL CA bit set: this is used as a workaround if the basicConstraints extension is absent.
SSL Server: The extended key usage extension must be absent or include the web server authentication and/or one of the SGC OIDs. keyUsage must be absent or it must have the digitalSignature set, the keyEncipherment set, or both bits set. The Netscape certificate type must be absent or have the SSL server bit set.
SSL Server CA: The extended key usage extension must be absent or include the web server authentication and/or one of the SGC OIDs. The Netscape certificate type must be absent or the SSL CA bit must be set: this is used as a workaround if the basicConstraints extension is absent.
Netscape SSL Server: For Netscape SSL clients to connect to an SSL server; it must have the keyEncipherment bit set if the keyUsage extension is present. This isn't always valid because some cipher suites use the key for digital signing. Otherwise it is the same as a normal SSL server.
Common S/MIME Client Tests: The extended key usage extension must be absent or include the email protection OID. The Netscape certificate type must be absent or should have the S/MIME bit set. If the S/MIME bit is not set in Netscape certificate type, then the SSL client bit is tolerated as an alternative but a warning is shown: this is because some Verisign certificates don't set the S/MIME bit.
S/MIME Signing: In addition to the common S/MIME client tests, the digitalSignature bit must be set if the keyUsage extension is present.
S/MIME Encryption: In addition to the common S/MIME tests, the keyEncipherment bit must be set if the keyUsage extension is present.
S/MIME CA: The extended key usage extension must be absent or include the email protection OID. The Netscape certificate type must be absent or must have the S/MIME CA bit set: this is used as a workaround if the basicConstraints extension is absent.
CRL Signing: The keyUsage extension must be absent or it must have the CRL signing bit set.
CRL Signing CA: The normal CA tests apply, except the basicConstraints extension must be present.

-setalias arg

Set the alias of the certificate, allowing the certificate to be referred to using a nickname, such as “Steve's Certificate”.

-trustout

Output a trusted certificate (the default if any trust settings are modified). An ordinary or trusted certificate can be input, but by default an ordinary certificate is output and any trust settings are discarded.

The x509 utility can be used to sign certificates and requests: it can thus behave like a mini CA. The following are x509 signing options:

-CA file: The CA certificate to be used for signing. When this option is present, x509 behaves like a mini CA. The input file is signed by the CA using this option; that is, its issuer name is set to the subject name of the CA and it is digitally signed using the CA's private key.

This option is normally combined with the -req option. Without the -req option, the input is a certificate which must be self-signed.
-CAcreateserial: Create the CA serial number file if it does not exist instead of generating an error. The file will contain the serial number ‘02’ and the certificate being signed will have ‘1’ as its serial number.
-CAform der | pem: The format of the CA certificate file. The default is pem.
-CAkey file: Set the CA private key to sign a certificate with. Otherwise it is assumed that the CA private key is present in the CA certificate file.
-CAkeyform der | pem: The format of the CA private key. The default is pem.
-CAserial file: Use the serial number in file to sign a certificate. The file should consist of one line containing an even number of hex digits with the serial number to use. After each use the serial number is incremented and written out to the file again.

The default filename consists of the CA certificate file base name with .srl appended. For example, if the CA certificate file is called mycacert.pem, it expects to find a serial number file called mycacert.srl.
-checkend arg: Check whether the certificate expires in the next arg seconds. If so, exit with return value 1; otherwise exit with return value 0.
-clrext: Delete any extensions from a certificate. This option is used when a certificate is being created from another certificate (for example with the -signkey or the -CA options). Normally, all extensions are retained.
-days arg: The number of days to make a certificate valid for. The default is 30 days.
-extensions section: The section to add certificate extensions from. If this option is not specified, the extensions should either be contained in the unnamed (default) section or the default section should contain a variable called “extensions” which contains the section to use.
-extfile file: File containing certificate extensions to use. If not specified, no extensions are added to the certificate.
-force_pubkey key: Set the public key of the certificate to the public key contained in key.
-keyform der | pem: The format of the key file used in the -force_pubkey and -signkey options.
-new: Generate a new certificate using the subject given by -set_subject and signed by -signkey. If no public key is provided with -force_pubkey, the resulting certificate is self-signed. This option cannot be used with -in or -req.
-req: Expect a certificate request on input instead of a certificate. This option cannot be used with -new.
-set_issuer name: The issuer name to use. name must be formatted as /type0=value0/type1=value1/type2=...; characters may be escaped by ‘\’ (backslash); no spaces are skipped.
-set_serial n: The serial number to use. This option can be used with either the -signkey or -CA options. If used in conjunction with the -CA option, the serial number file (as specified by the -CAserial or -CAcreateserial options) is not used.

The serial number can be decimal or hex (if preceded by ‘0x’). Negative serial numbers can also be specified but their use is not recommended.
-set_subject name: The subject name to use. name must be formatted as /type0=value0/type1=value1/type2=...; characters may be escaped by ‘\’ (backslash); no spaces are skipped.
-signkey file: Self-sign file using the supplied private key.

If the input file is a certificate, it sets the issuer name to the subject name (i.e. makes it self-signed), changes the public key to the supplied value, and changes the start and end dates. The start date is set to the current time and the end date is set to a value determined by the -days option. Any certificate extensions are retained unless the -clrext option is supplied.

If the input is a certificate request, a self-signed certificate is created using the supplied private key using the subject name in the request.
-utf8: Interpret field values read from a terminal or obtained from a configuration file as UTF-8 strings. By default, they are interpreted as ASCII.
-x509toreq: Convert a certificate into a certificate request. The -signkey option is used to pass the required private key.

COMMON NOTATION

Several commands share a common syntax, as detailed below.

Password arguments, typically specified using -passin and -passout for input and output passwords, allow passwords to be obtained from a variety of sources. Both of these options take a single argument, described below. If no password argument is given and a password is required, then the user is prompted to enter one: this will typically be read from the current terminal with echoing turned off.

Input/output formats, typically specified using -inform and -outform, indicate the format being read from or written to. The argument is case insensitive.

ENVIRONMENT

The following environment variables affect the execution of openssl:

FILES

STANDARDS

T. Dierks and C. Allen, The TLS Protocol Version 1.0, RFC 2246, January 1999.

M. Wahl, S. Killie, and T. Howes, Lightweight Directory Access Protocol (v3): UTF-8 String Representation of Distinguished Names, RFC 2253, December 1997.

B. Kaliski, PKCS #7: Cryptographic Message Syntax Version 1.5, RFC 2315, March 1998.

R. Housley, W. Ford, W. Polk, and D. Solo, Internet X.509 Public Key Infrastructure Certificate and CRL Profile, RFC 2459, January 1999.

M. Myers, R. Ankney, A. Malpani, S. Galperin, and C. Adams, X.509 Internet Public Key Infrastructure Online Certificate Status Protocol – OCSP, RFC 2560, June 1999.

R. Housley, Cryptographic Message Syntax, RFC 2630, June 1999.

P. Chown, Advanced Encryption Standard (AES) Ciphersuites for Transport Layer Security (TLS), RFC 3268, June 2002.