X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=doc%2Fcrypto%2FEVP_VerifyInit.pod;h=9097f094105d50d9cadc053e9df7df959749dabd;hb=0501f02b060e45f2e2d275d779d864f3159f8ea9;hp=3b5e07f4ade9e9e730f361023e3cdfee474290de;hpb=f71732627a9f528a4966e55853bdf88aec207fae;p=oweals%2Fopenssl.git diff --git a/doc/crypto/EVP_VerifyInit.pod b/doc/crypto/EVP_VerifyInit.pod index 3b5e07f4ad..9097f09410 100644 --- a/doc/crypto/EVP_VerifyInit.pod +++ b/doc/crypto/EVP_VerifyInit.pod @@ -8,30 +8,35 @@ EVP_VerifyInit, EVP_VerifyUpdate, EVP_VerifyFinal - EVP signature verification f #include - void EVP_VerifyInit(EVP_MD_CTX *ctx, const EVP_MD *type); - void EVP_VerifyUpdate(EVP_MD_CTX *ctx, const void *d, unsigned int cnt); + int EVP_VerifyInit_ex(EVP_MD_CTX *ctx, const EVP_MD *type, ENGINE *impl); + int EVP_VerifyUpdate(EVP_MD_CTX *ctx, const void *d, unsigned int cnt); int EVP_VerifyFinal(EVP_MD_CTX *ctx,unsigned char *sigbuf, unsigned int siglen,EVP_PKEY *pkey); + int EVP_VerifyInit(EVP_MD_CTX *ctx, const EVP_MD *type); + =head1 DESCRIPTION The EVP signature verification routines are a high level interface to digital signatures. -EVP_VerifyInit() initialises a verification context B to using digest -B: this will typically be supplied by a function such as EVP_sha1(). +EVP_VerifyInit_ex() sets up verification context B to use digest +B from ENGINE B. B must be initialized by calling +EVP_MD_CTX_init() before calling this function. EVP_VerifyUpdate() hashes B bytes of data at B into the -verification context B. This funtion can be called several times on the +verification context B. This function can be called several times on the same B to include additional data. EVP_VerifyFinal() verifies the data in B using the public key B -and against the B bytes at B. After calling EVP_VerifyFinal() -no additional calls to EVP_VerifyUpdate() can be made, but EVP_VerifyInit() -can be called to initialiase a new verification operation. +and against the B bytes at B. + +EVP_VerifyInit() initializes verification context B to use the default +implementation of digest B. =head1 RETURN VALUES -EVP_VerifyInit() and EVP_VerifyUpdate() do not return values. +EVP_VerifyInit_ex() and EVP_VerifyUpdate() return 1 for success and 0 for +failure. EVP_VerifyFinal() returns 1 for a correct signature, 0 for failure and -1 if some other error occurred. @@ -49,23 +54,42 @@ digest algorithm must be used with the correct public key type. A list of algorithms and associated public key algorithms appears in L. +The call to EVP_VerifyFinal() internally finalizes a copy of the digest context. +This means that calls to 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 BUGS -Several of the functions do not return values: maybe they should. Although the -internal digest operations will never fail some future hardware based operations -might. +Older versions of this documentation wrongly stated that calls to +EVP_VerifyUpdate() could not be made after calling EVP_VerifyFinal(). + +Since the public 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_VerifyDigest*() function. =head1 SEE ALSO +L, L, L, L, L, L, L, L, L, L, -L, L +L, L =head1 HISTORY EVP_VerifyInit(), EVP_VerifyUpdate() and EVP_VerifyFinal() are available in all versions of SSLeay and OpenSSL. +EVP_VerifyInit_ex() was added in OpenSSL 0.9.7 + =cut