diff options
| -rw-r--r-- | doc/crypto/HMAC.pod | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/doc/crypto/HMAC.pod b/doc/crypto/HMAC.pod index 87f7e33086..219c9ba208 100644 --- a/doc/crypto/HMAC.pod +++ b/doc/crypto/HMAC.pod @@ -57,7 +57,8 @@ B<key_len> bytes long. It places the result in B<md> (which must have space for the output of the hash function, which is no more than B<EVP_MAX_MD_SIZE> bytes). If B<md> is NULL, the digest is placed in a static array. The size of -the output is placed in B<md_len>, unless it is B<NULL>. +the output is placed in B<md_len>, unless it is B<NULL>. Note: passing a NULL +value for B<md> to use the static array is not thread safe. B<evp_md> can be EVP_sha1(), EVP_ripemd160() etc. |