diff options
Diffstat (limited to 'doc/man3/EVP_DigestSignInit.pod')
| -rw-r--r-- | doc/man3/EVP_DigestSignInit.pod | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/doc/man3/EVP_DigestSignInit.pod b/doc/man3/EVP_DigestSignInit.pod index 07e99db231..9916cf0f10 100644 --- a/doc/man3/EVP_DigestSignInit.pod +++ b/doc/man3/EVP_DigestSignInit.pod @@ -128,13 +128,12 @@ I<siglen> parameter should contain the length of the I<sig> buffer. If the call is successful the signature is written to I<sig> and the amount of data written to I<siglen>. -EVP_DigestSign() signs I<tbslen> bytes of data at I<tbs> and places the -signature in I<sig> and its length in I<siglen> in a similar way to -EVP_DigestSignFinal(). In the event of a failure EVP_DigestSign() cannot be -called again without reinitialising the EVP_MD_CTX. If I<sig> is NULL before the -call then I<siglen> will be populated with the required size for the I<sig> -buffer. If I<sig> is non-NULL before the call then I<siglen> should contain the -length of the I<sig> buffer. +EVP_DigestSign() is similar to a single call to EVP_DigestSignUpdate() and +EVP_DigestSignFinal(). +Unless I<sig> is NULL, EVP_DigestSign() signs the data I<tbs> of length I<tbslen> +bytes and places the signature in a buffer I<sig> of size I<siglen>. +If I<sig> is NULL, the maximum necessary size of the signature buffer is written +to the I<siglen> parameter. =head1 RETURN VALUES @@ -179,6 +178,10 @@ multiple times on a context and the parameters set by previous calls should be preserved if the I<pkey> parameter is NULL. The call then just resets the state of the I<ctx>. +EVP_DigestSign() can not be called again, once a signature is generated (by +passing I<sig> as non NULL), unless the B<EVP_MD_CTX> is reinitialised by +calling EVP_DigestSignInit_ex(). + Ignoring failure returns of EVP_DigestSignInit() and EVP_DigestSignInit_ex() functions can lead to subsequent undefined behavior when calling EVP_DigestSignUpdate(), EVP_DigestSignFinal(), or EVP_DigestSign(). |