diff options
Diffstat (limited to 'doc/crypto/EVP_DigestVerifyInit.pod')
| -rw-r--r-- | doc/crypto/EVP_DigestVerifyInit.pod | 83 |
1 files changed, 0 insertions, 83 deletions
diff --git a/doc/crypto/EVP_DigestVerifyInit.pod b/doc/crypto/EVP_DigestVerifyInit.pod deleted file mode 100644 index 347c51166306..000000000000 --- a/doc/crypto/EVP_DigestVerifyInit.pod +++ /dev/null @@ -1,83 +0,0 @@ -=pod - -=head1 NAME - -EVP_DigestVerifyInit, EVP_DigestVerifyUpdate, EVP_DigestVerifyFinal - EVP signature verification functions - -=head1 SYNOPSIS - - #include <openssl/evp.h> - - int EVP_DigestVerifyInit(EVP_MD_CTX *ctx, EVP_PKEY_CTX **pctx, - const EVP_MD *type, ENGINE *e, EVP_PKEY *pkey); - int EVP_DigestVerifyUpdate(EVP_MD_CTX *ctx, const void *d, size_t cnt); - int EVP_DigestVerifyFinal(EVP_MD_CTX *ctx, const unsigned char *sig, size_t siglen); - -=head1 DESCRIPTION - -The EVP signature routines are a high level interface to digital signatures. - -EVP_DigestVerifyInit() sets up verification context B<ctx> to use digest -B<type> from ENGINE B<impl> and public key B<pkey>. B<ctx> must be initialized -with EVP_MD_CTX_init() before calling this function. If B<pctx> is not NULL the -EVP_PKEY_CTX of the verification operation will be written to B<*pctx>: this -can be used to set alternative verification options. - -EVP_DigestVerifyUpdate() hashes B<cnt> bytes of data at B<d> into the -verification context B<ctx>. This function can be called several times on the -same B<ctx> to include additional data. This function is currently implemented -using a macro. - -EVP_DigestVerifyFinal() verifies the data in B<ctx> against the signature in -B<sig> of length B<siglen>. - -=head1 RETURN VALUES - -EVP_DigestVerifyInit() and EVP_DigestVerifyUpdate() return 1 for success and 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. - -EVP_DigestVerifyFinal() returns 1 for success; any other value indicates -failure. A return value of zero indicates that the signature did not verify -successfully (that is, tbs did not match the original data or the signature had -an invalid form), while other values indicate a more serious error (and -sometimes also indicate an invalid signature form). - -The error codes can be obtained from L<ERR_get_error(3)|ERR_get_error(3)>. - -=head1 NOTES - -The B<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. - -In previous versions of OpenSSL there was a link between message digest types -and public key algorithms. This meant that "clone" digests such as EVP_dss1() -needed to be used to sign using SHA1 and DSA. This is no longer necessary and -the use of clone digest is now discouraged. - -For some key types and parameters the random number generator must be seeded -or the operation will fail. - -The call to EVP_DigestVerifyFinal() internally finalizes a copy of the digest -context. This means that EVP_VerifyUpdate() and EVP_VerifyFinal() can -be called later to digest and verify 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_cleanup() or a memory leak -will occur. - -=head1 SEE ALSO - -L<EVP_DigestSignInit(3)|EVP_DigestSignInit(3)>, -L<EVP_DigestInit(3)|EVP_DigestInit(3)>, L<err(3)|err(3)>, -L<evp(3)|evp(3)>, L<hmac(3)|hmac(3)>, L<md2(3)|md2(3)>, -L<md5(3)|md5(3)>, L<mdc2(3)|mdc2(3)>, L<ripemd(3)|ripemd(3)>, -L<sha(3)|sha(3)>, L<dgst(1)|dgst(1)> - -=head1 HISTORY - -EVP_DigestVerifyInit(), EVP_DigestVerifyUpdate() and EVP_DigestVerifyFinal() -were first added to OpenSSL 1.0.0. - -=cut |