=head1 NAME
-EVP_DigestSignInit, EVP_DigestSignUpdate, EVP_DigestSignFinal - EVP signing functions
+EVP_DigestSignInit, EVP_DigestSignUpdate, EVP_DigestSignFinal,
+EVP_DigestSign - EVP signing functions
=head1 SYNOPSIS
int EVP_DigestSignUpdate(EVP_MD_CTX *ctx, const void *d, size_t cnt);
int EVP_DigestSignFinal(EVP_MD_CTX *ctx, unsigned char *sig, size_t *siglen);
+ int EVP_DigestSign(EVP_MD_CTX *ctx, unsigned char *sigret,
+ size_t *siglen, const unsigned char *tbs,
+ size_t tbslen);
+
=head1 DESCRIPTION
The EVP signature routines are a high level interface to digital signatures.
EVP_DigestSignInit() sets up signing context B<ctx> to use digest B<type> from
-ENGINE B<
impl> and private key B<pkey>. B<ctx> must be created with
+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
call is successful the signature is written to B<sig> and the amount of data
written to B<siglen>.
+EVP_DigestSign() signs B<tbslen> bytes of data at B<tbs> and places the
+signature in B<sig> and its length in B<siglen> in a similar way to
+EVP_DigestSignFinal().
+
=head1 RETURN VALUES
-EVP_DigestSignInit() EVP_DigestSignUpdate() and EVP_DigestSignaFinal() 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_DigestSignInit(), EVP_DigestSignUpdate(), EVP_DigestSignaFinal() and
+EVP_DigestSign() 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.
The error codes can be obtained from L<ERR_get_error(3)>.
preference to the low level interfaces. This is because the code then becomes
transparent to the algorithm used and much more flexible.
+EVP_DigestSign() is a one shot operation which signs a single block of data
+in one function. For algorithms that support streaming it is equivalent to
+calling EVP_DigestSignUpdate() and EVP_DigestSignFinal(). For algorithms which
+do not support streaming (e.g. PureEdDSA) it is the only way to sign data.
+
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
EVP_DigestSignFinal() can be called later to digest and sign 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
+be cleaned up after use by calling EVP_MD_CTX_free() or a memory leak
will occur.
The use of EVP_PKEY_size() with these functions is discouraged because some
=head1 SEE ALSO
L<EVP_DigestVerifyInit(3)>,
-L<EVP_DigestInit(3)>, L<err(7)>,
+L<EVP_DigestInit(3)>,
L<evp(7)>, L<HMAC(3)>, L<MD2(3)>,
L<MD5(3)>, L<MDC2(3)>, L<RIPEMD160(3)>,
L<SHA1(3)>, L<dgst(1)>
=head1 COPYRIGHT
-Copyright 2006-2016 The OpenSSL Project Authors. All Rights Reserved.
+Copyright 2006-2018 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the OpenSSL license (the "License"). You may not use
this file except in compliance with the License. You can obtain a copy
projects / openssl.git / blobdiff