1=pod
2
3=head1 NAME
4
5RSA_sign, RSA_verify - RSA signatures
6
7=head1 SYNOPSIS
8
9 #include <openssl/rsa.h>
10
11 int RSA_sign(int type, unsigned char *m, unsigned int m_len,
12    unsigned char *sigret, unsigned int *siglen, RSA *rsa);
13
14 int RSA_verify(int type, unsigned char *m, unsigned int m_len,
15    unsigned char *sigbuf, unsigned int siglen, RSA *rsa);
16
17=head1 DESCRIPTION
18
19RSA_sign() signs the message digest B<m> of size B<m_len> using the
20private key B<rsa> as specified in PKCS #1 v2.0. It stores the
21signature in B<sigret> and the signature size in B<siglen>. B<sigret>
22must point to RSA_size(B<rsa>) bytes of memory.
23
24B<type> denotes the message digest algorithm that was used to generate
25B<m>. It usually is one of B<NID_sha1>, B<NID_ripemd160> and B<NID_md5>;
26see L<objects(3)|objects(3)> for details. If B<type> is B<NID_md5_sha1>,
27an SSL signature (MD5 and SHA1 message digests with PKCS #1 padding
28and no algorithm identifier) is created.
29
30RSA_verify() verifies that the signature B<sigbuf> of size B<siglen>
31matches a given message digest B<m> of size B<m_len>. B<type> denotes
32the message digest algorithm that was used to generate the signature.
33B<rsa> is the signer's public key.
34
35=head1 RETURN VALUES
36
37RSA_sign() returns 1 on success, 0 otherwise.  RSA_verify() returns 1
38on successful verification, 0 otherwise.
39
40The error codes can be obtained by L<ERR_get_error(3)|ERR_get_error(3)>.
41
42=head1 BUGS
43
44Certain signatures with an improper algorithm identifier are accepted
45for compatibility with SSLeay 0.4.5 :-)
46
47=head1 CONFORMING TO
48
49SSL, PKCS #1 v2.0
50
51=head1 SEE ALSO
52
53L<ERR_get_error(3)|ERR_get_error(3)>, L<objects(3)|objects(3)>,
54L<rsa(3)|rsa(3)>, L<RSA_private_encrypt(3)|RSA_private_encrypt(3)>,
55L<RSA_public_decrypt(3)|RSA_public_decrypt(3)> 
56
57=head1 HISTORY
58
59RSA_sign() and RSA_verify() are available in all versions of SSLeay
60and OpenSSL.
61
62=cut
63