=head1 NAME
-EVP_PKEY_size,
-EVP_SignInit, EVP_SignInit_ex, EVP_SignUpdate, EVP_SignFinal - EVP signing
-functions
+EVP_SignInit, EVP_SignInit_ex, EVP_SignUpdate, EVP_SignFinal
+- EVP signing functions
=head1 SYNOPSIS
void EVP_SignInit(EVP_MD_CTX *ctx, const EVP_MD *type);
- int EVP_PKEY_size(EVP_PKEY *pkey);
-
=head1 DESCRIPTION
The EVP signature routines are a high level interface to digital
same B<ctx> to include additional data.
EVP_SignFinal() signs the data in B<ctx> using the private key B<pkey> and
-places the signature in B<sig>. B<sig> must be at least EVP_PKEY_size(pkey)
+places the signature in B<sig>. B<sig> must be at least C<EVP_PKEY_size(pkey)>
bytes in size. B<s> is an OUT parameter, and not used as an IN parameter.
The number of bytes of data written (i.e. the length of the signature)
-will be written to the integer at B<s>, at most EVP_PKEY_size(pkey) bytes
+will be written to the integer at B<s>, at most C<EVP_PKEY_size(pkey)> bytes
will be written.
EVP_SignInit() initializes a signing context B<ctx> to use the default
implementation of digest B<type>.
-EVP_PKEY_size() returns the maximum size of a signature in bytes. The actual
-signature returned by EVP_SignFinal() may be smaller.
-
=head1 RETURN VALUES
EVP_SignInit_ex(), EVP_SignUpdate() and EVP_SignFinal() return 1
for success and 0 for failure.
-EVP_PKEY_size() returns the maximum size of a signature in bytes.
-
The error codes can be obtained by L<ERR_get_error(3)>.
=head1 NOTES
preference to the low level interfaces. This is because the code then becomes
transparent to the algorithm used and much more flexible.
-Due to the link between message digests and public key algorithms the correct
-digest algorithm must be used with the correct public key type. A list of
-algorithms and associated public key algorithms appears in
-L<EVP_DigestInit(3)>.
-
-When signing with DSA private keys the random number generator must be seeded
-or the operation will fail. The random number generator does not need to be
-seeded for RSA signatures.
+When signing with DSA private keys the random number generator must be seeded.
+If the automatic seeding or reseeding of the OpenSSL CSPRNG fails due to
+external circumstances (see L<RAND(7)>), the operation will fail.
+This requirement does not hold for RSA signatures.
The call to EVP_SignFinal() internally finalizes a copy of the digest context.
This means that calls to EVP_SignUpdate() and EVP_SignFinal() 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.
=head1 BUGS
=head1 SEE ALSO
+L<EVP_PKEY_size(3)>, L<EVP_PKEY_bits(3)>, L<EVP_PKEY_security_bits(3)>,
L<EVP_VerifyInit(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)>
+L<SHA1(3)>, L<openssl-dgst(1)>
=head1 COPYRIGHT
-Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
+Copyright 2000-2018 The OpenSSL Project Authors. All Rights Reserved.
-Licensed under the OpenSSL license (the "License"). You may not use
+Licensed under the Apache License 2.0 (the "License"). You may not use
this file except in compliance with the License. You can obtain a copy
in the file LICENSE in the source distribution or at
L<https://www.openssl.org/source/license.html>.
projects / openssl.git / blobdiff