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RSA_PKEY_CTX_CTRL(3) | Library Functions Manual | RSA_PKEY_CTX_CTRL(3) |
NAME
RSA_pkey_ctx_ctrl
,
EVP_PKEY_CTX_set_rsa_padding
,
EVP_PKEY_CTX_get_rsa_padding
,
EVP_PKEY_CTX_set_rsa_keygen_bits
,
EVP_PKEY_CTX_set_rsa_keygen_pubexp
,
EVP_PKEY_CTX_set_rsa_mgf1_md
,
EVP_PKEY_CTX_get_rsa_mgf1_md
,
EVP_PKEY_CTX_set_rsa_oaep_md
,
EVP_PKEY_CTX_get_rsa_oaep_md
,
EVP_PKEY_CTX_set0_rsa_oaep_label
,
EVP_PKEY_CTX_get0_rsa_oaep_label
,
EVP_PKEY_CTX_set_rsa_pss_saltlen
,
EVP_PKEY_CTX_get_rsa_pss_saltlen
,
EVP_PKEY_CTX_set_rsa_pss_keygen_md
,
EVP_PKEY_CTX_set_rsa_pss_keygen_mgf1_md
,
EVP_PKEY_CTX_set_rsa_pss_keygen_saltlen
—
RSA private key control operations
SYNOPSIS
#include
<openssl/rsa.h>
int
RSA_pkey_ctx_ctrl
(EVP_PKEY_CTX
*ctx, int optype,
int cmd, int
p1, void *p2);
int
EVP_PKEY_CTX_set_rsa_padding
(EVP_PKEY_CTX
*ctx, int pad);
int
EVP_PKEY_CTX_get_rsa_padding
(EVP_PKEY_CTX
*ctx, int *ppad);
int
EVP_PKEY_CTX_set_rsa_keygen_bits
(EVP_PKEY_CTX
*ctx, int mbits);
int
EVP_PKEY_CTX_set_rsa_keygen_pubexp
(EVP_PKEY_CTX
*ctx, BIGNUM *pubexp);
int
EVP_PKEY_CTX_set_rsa_mgf1_md
(EVP_PKEY_CTX
*ctx, const EVP_MD *md);
int
EVP_PKEY_CTX_get_rsa_mgf1_md
(EVP_PKEY_CTX
*ctx, const EVP_MD **pmd);
int
EVP_PKEY_CTX_set_rsa_oaep_md
(EVP_PKEY_CTX
*ctx, const EVP_MD *md);
int
EVP_PKEY_CTX_get_rsa_oaep_md
(EVP_PKEY_CTX
*ctx, const EVP_MD **pmd);
int
EVP_PKEY_CTX_set0_rsa_oaep_label
(EVP_PKEY_CTX
*ctx, unsigned char *label,
int len);
int
EVP_PKEY_CTX_get0_rsa_oaep_label
(EVP_PKEY_CTX
*ctx, unsigned char **plabel);
int
EVP_PKEY_CTX_set_rsa_pss_saltlen
(EVP_PKEY_CTX
*ctx, int len);
int
EVP_PKEY_CTX_get_rsa_pss_saltlen
(EVP_PKEY_CTX
*ctx, int *plen);
int
EVP_PKEY_CTX_set_rsa_pss_keygen_md
(EVP_PKEY_CTX
*pctx, const EVP_MD *md);
int
EVP_PKEY_CTX_set_rsa_pss_keygen_mgf1_md
(EVP_PKEY_CTX
*pctx, const EVP_MD *md);
int
EVP_PKEY_CTX_set_rsa_pss_keygen_saltlen
(EVP_PKEY_CTX
*pctx, int saltlen);
DESCRIPTION
The functionRSA_pkey_ctx_ctrl
() is a shallow
wrapper around
EVP_PKEY_CTX_ctrl(3)
which only succeeds if ctx matches either
EVP_PKEY_RSA
or
EVP_PKEY_RSA_PSS
.
All the remaining "functions" are implemented as macros.
The EVP_PKEY_CTX_set_rsa_padding
() macro sets
the RSA padding mode for ctx. The
pad parameter can take the value
RSA_PKCS1_PADDING
for PKCS#1 padding,
RSA_NO_PADDING
for no padding,
RSA_PKCS1_OAEP_PADDING
for OAEP padding
(encrypt and decrypt only),
RSA_X931_PADDING
for X9.31 padding
(signature operations only) and
RSA_PKCS1_PSS_PADDING
(sign and verify
only). Only the last one can be used with keys of the type
EVP_PKEY_RSA_PSS
.
Two RSA padding modes behave differently if
EVP_PKEY_CTX_set_signature_md(3)
is used. If this macro is called for PKCS#1 padding, the plaintext buffer is
an actual digest value and is encapsulated in a
DigestInfo structure according to PKCS#1 when
signing and this structure is expected (and stripped off) when verifying. If
this control is not used with RSA and PKCS#1 padding then the supplied data is
used directly and not encapsulated. In the case of X9.31 padding for RSA the
algorithm identifier byte is added or checked and removed if this control is
called. If it is not called then the first byte of the plaintext buffer is
expected to be the algorithm identifier byte.
The EVP_PKEY_CTX_get_rsa_padding
() macro
retrieves the RSA padding mode for ctx.
The EVP_PKEY_CTX_set_rsa_keygen_bits
() macro
sets the RSA key length for RSA or RSA-PSS key generation to
mbits. The smallest supported value is 512
bits. If not specified, 1024 bits is used.
The EVP_PKEY_CTX_set_rsa_keygen_pubexp
()
macro sets the public exponent value for RSA or RSA-PSS key generation to
pubexp. Currently, it should be an odd
integer. The pubexp pointer is used
internally by this function, so it should not be modified or freed after the
call. If this macro is not called, then 65537 is used.
The EVP_PKEY_CTX_set_rsa_mgf1_md
() macro sets
the MGF1 digest for RSA padding schemes to
md. Unless explicitly specified, the signing
digest is used. The padding mode must have been set to
RSA_PKCS1_OAEP_PADDING
or
RSA_PKCS1_PSS_PADDING
. If the key is of the
type EVP_PKEY_RSA_PSS
and has usage
restrictions, an error occurs if an attempt is made to set the digest to
anything other than the restricted value.
The EVP_PKEY_CTX_get_rsa_mgf1_md
() macro
retrieves the MGF1 digest for ctx. Unless
explicitly specified, the signing digest is used. The padding mode must have
been set to RSA_PKCS1_OAEP_PADDING
or
RSA_PKCS1_PSS_PADDING
.
Optimal asymmetric encryption padding
The following macros require that the padding mode was set toRSA_PKCS1_OAEP_PADDING
.
The EVP_PKEY_CTX_set_rsa_oaep_md
() macro sets
the message digest type used in RSA OAEP to
md.
The EVP_PKEY_CTX_get_rsa_oaep_md
() macro gets
the message digest type used in RSA OAEP to
*pmd.
The EVP_PKEY_CTX_set0_rsa_oaep_label
() macro
sets the RSA OAEP label to label and its
length to len. If
label is
NULL
or
len is 0, the label is cleared. The library
takes ownership of the label so the caller should not free the original memory
pointed to by label.
The EVP_PKEY_CTX_get0_rsa_oaep_label
() macro
gets the RSA OAEP label to *plabel. The
return value is the label length. The resulting pointer is owned by the
library and should not be freed by the caller.
Probabilistic signature scheme
The following macros require that the padding mode was set toRSA_PKCS1_PSS_PADDING
.
The EVP_PKEY_CTX_set_rsa_pss_saltlen
() macro
sets the RSA PSS salt length to len. Three
special values are supported:
RSA_PSS_SALTLEN_DIGEST
sets the salt length
to the digest length. RSA_PSS_SALTLEN_MAX
sets the salt length to the maximum permissible value. When signing,
RSA_PSS_SALTLEN_AUTO
sets the salt length
to the maximum permissible value. When verifying,
RSA_PSS_SALTLEN_AUTO
causes the salt length
to be automatically determined based on the PSS block structure. If this macro
is not called, a salt length value of
RSA_PSS_SALTLEN_AUTO
is used by default.
If the key has usage restrictions and an attempt is made to set the salt length
below the minimum value, an error occurs. Also, if the key has usage
restrictions, RSA_PSS_SALTLEN_AUTO
is not
supported for verification.
The EVP_PKEY_CTX_get_rsa_pss_saltlen
() macro
retrieves the RSA PSS salt length for ctx.
Optional parameter restrictions can be specified when generating a PSS key. If
any restrictions are set using the macros described below, then all parameters
are restricted. For example, setting a minimum salt length also restricts the
digest and MGF1 algorithms. If any restrictions are in place, then they are
reflected in the corresponding parameters of the public key when (for example)
a certificate request is signed.
EVP_PKEY_CTX_set_rsa_pss_keygen_md
()
restricts the digest algorithm the generated key can use to
md.
EVP_PKEY_CTX_set_rsa_pss_keygen_mgf1_md
()
restricts the MGF1 algorithm the generated key can use to
md.
EVP_PKEY_CTX_set_rsa_pss_keygen_saltlen
()
restricts the minimum salt length to saltlen.
RETURN VALUES
These functions return a positive value for success or 0 or a negative value for failure. In particular, a return value of -2 indicates the operation is not supported by the public key algorithm.SEE ALSO
EVP_DigestInit(3), EVP_PKEY_CTX_ctrl(3), EVP_PKEY_CTX_new(3), EVP_PKEY_decrypt(3), EVP_PKEY_derive(3), EVP_PKEY_encrypt(3), EVP_PKEY_get_default_digest_nid(3), EVP_PKEY_keygen(3), EVP_PKEY_meth_set_ctrl(3), EVP_PKEY_sign(3), EVP_PKEY_verify(3), EVP_PKEY_verify_recover(3)HISTORY
The functionsEVP_PKEY_CTX_set_rsa_padding
(),
EVP_PKEY_CTX_set_rsa_keygen_bits
(),
EVP_PKEY_CTX_set_rsa_keygen_pubexp
(), and
EVP_PKEY_CTX_set_rsa_pss_saltlen
() first
appeared in OpenSSL 1.0.0 and have been available since
OpenBSD 4.9.
The functions EVP_PKEY_CTX_get_rsa_padding
(),
EVP_PKEY_CTX_set_rsa_mgf1_md
(),
EVP_PKEY_CTX_get_rsa_mgf1_md
(), and
EVP_PKEY_CTX_get_rsa_pss_saltlen
() first
appeared in OpenSSL 1.0.1 and have been available since
OpenBSD 5.3.
The functions EVP_PKEY_CTX_set_rsa_oaep_md
(),
EVP_PKEY_CTX_get_rsa_oaep_md
(),
EVP_PKEY_CTX_set0_rsa_oaep_label
(), and
EVP_PKEY_CTX_get0_rsa_oaep_label
() first
appeared in OpenSSL 1.0.2 and have been available since
OpenBSD 6.7.
The function RSA_pkey_ctx_ctrl
() first
appeared in OpenSSL 1.1.1 and has been available since
OpenBSD 6.7.November 1, 2019 | Debian |