Sortix nightly manual
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|EVP_SIGNINIT(3)||Library Functions Manual||EVP_SIGNINIT(3)|
EVP signing functions
EVP_SignInit_ex(EVP_MD_CTX *ctx, const EVP_MD *type, ENGINE *impl); int
EVP_SignUpdate(EVP_MD_CTX *ctx, const void *d, unsigned int cnt); int
EVP_SignFinal(EVP_MD_CTX *ctx, unsigned char *sig, unsigned int *s, EVP_PKEY *pkey); void
EVP_SignInit(EVP_MD_CTX *ctx, const EVP_MD *type); int
EVP_PKEY_size(const EVP_PKEY *pkey); int
EVP_PKEY_bits(const EVP_PKEY *pkey);
EVP_SignInit_ex() sets up a signing context ctx to use the digest type from ENGINE impl. ctx must be initialized with EVP_MD_CTX_init(3) before calling this function.
EVP_SignUpdate() hashes cnt bytes of data at d into the signature context ctx. This function can be called several times on the same ctx to include additional data.
EVP_SignFinal() signs the data in ctx using the private key pkey and places the signature in sig. sig must be at least
EVP_PKEY_size(pkey) bytes in size. s is an OUT parameter, and not used as an IN parameter. The number of bytes of data written (i.e. the length of the signature) will be written to the integer at s. At most
EVP_PKEY_size(pkey) bytes will be written.
EVP_SignInit() initializes a signing context ctx to use the default implementation of digest type.
EVP_PKEY_size() returns the maximum size of a signature in bytes. The actual signature returned by
EVP_SignFinal() may be smaller. The EVP interface to digital signatures should almost always be used in preference to the low level interfaces. This is because the code then becomes transparent to the algorithm used and much more flexible. The call to
EVP_SignFinal() internally finalizes a copy of the digest context. This means that calls to
EVP_SignFinal() can be called later to digest and sign additional data. Since only a copy of the digest context is ever finalized, the context must be cleaned up after use by calling EVP_MD_CTX_free(3) or a memory leak will occur.
EVP_SignFinal() return 1 for success and 0 for failure.
EVP_PKEY_size() returns the maximum size of a signature in bytes.
EVP_PKEY_bits() returns the number of significant bits in the key or 0 if an error occurs. The error codes can be obtained by ERR_get_error(3). evp(3), EVP_DigestInit(3), EVP_PKEY_asn1_set_public(3), EVP_VerifyInit(3)
EVP_SignFinal() first appeared in SSLeay 0.5.1.
EVP_PKEY_size() first appeared in SSLeay 0.6.0.
EVP_PKEY_bits() first appeared in SSLeay 0.9.0. These functions have been available since OpenBSD 2.4.
EVP_SignInit_ex() first appeared in OpenSSL 0.9.7 and has been available since OpenBSD 3.2.
EVP_SignUpdate() could not be made after calling
EVP_SignFinal(). Since the private key is passed in the call to
EVP_SignFinal(), any error relating to the private key (for example an unsuitable key and digest combination) will not be indicated until after potentially large amounts of data have been passed through
EVP_SignUpdate(). It is not possible to change the signing parameters using these function. The previous two bugs are fixed in the newer EVP_DigestSign* function.
|March 31, 2022||Debian|