[openssl-commits] [openssl] master update

[Matt Caswell]

The branch master has been updated
       via  be93b0e8638287bfaa8239ef64ee1c4a7cd818cb (commit)
      from  d4da95a7736e9e74ec47f9e0077ad0ef18a4faf6 (commit)


- Log -----------------------------------------------------------------
commit be93b0e8638287bfaa8239ef64ee1c4a7cd818cb
Author: Matt Caswell <matt at openssl.org>
Date:   Tue Apr 17 15:33:17 2018 +0100

    Update EVP_DigestSignInit() docs
    
    Explicitly state which digests can be used with which algorithms.
    
    Fixes #5854
    
    Reviewed-by: Rich Salz <rsalz at openssl.org>
    (Merged from https://github.com/openssl/openssl/pull/5992)

-----------------------------------------------------------------------

Summary of changes:
 doc/man3/EVP_DigestSignInit.pod | 49 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 48 insertions(+), 1 deletion(-)

diff --git a/doc/man3/EVP_DigestSignInit.pod b/doc/man3/EVP_DigestSignInit.pod
index 0c339fe..fc19c01 100644
--- a/doc/man3/EVP_DigestSignInit.pod
+++ b/doc/man3/EVP_DigestSignInit.pod
@@ -26,7 +26,54 @@ EVP_DigestSignInit() sets up signing context B<ctx> to use digest B<type> from
 ENGINE B<e> and private key B<pkey>. B<ctx> must be created with
 EVP_MD_CTX_new() before calling this function. If B<pctx> is not NULL the
 EVP_PKEY_CTX of the signing operation will be written to B<*pctx>: this can
-be used to set alternative signing options.
+be used to set alternative signing options. The digest B<type> may be NULL if
+the signing algorithm supports it.
+
+Only EVP_PKEY types that support signing can be used with these functions. This
+includes MAC algorithms where the MAC generation is considered as a form of
+"signing." Built-in EVP_PKEY types supported by these functions are CMAC,
+Poly1305, DSA, HMAC, RSA, SipHash, Ed25519 and Ed448.
+
+Not all digests can be used for all key types. The following combinations apply.
+
+=over 4
+
+=item DSA
+
+Supports SHA1, SHA224, SHA256, SHA384 and SHA512
+
+=item ECDSA
+
+Supports SHA1, SHA224, SHA256, SHA384, SHA512 and SM3
+
+=item RSA with no padding
+
+Supports no digests (the digest B<type> must be NULL)
+
+=item RSA with X931 padding
+
+Supports SHA1, SHA256, SHA384 and SHA512
+
+=item All other RSA padding types
+
+Support SHA1, SHA224, SHA256, SHA384, SHA512, MD5, MD5_SHA1, MD2, MD4, MDC2,
+SHA3-224, SHA3-256, SHA3-384, SHA3-512
+
+=item Ed25519 and Ed448
+
+Support no digests (the digest B<type> must be NULL)
+
+=item HMAC
+
+Supports any digest
+
+=item CMAC, Poly1305 and SipHash
+
+Will ignore any digest provided.
+
+=back
+
+If RSA-PSS is used and restrictions apply then the digest must match.
 
 EVP_DigestSignUpdate() hashes B<cnt> bytes of data at B<d> into the
 signature context B<ctx>. This function can be called several times on the