1RSA_sign(3)                         OpenSSL                        RSA_sign(3)
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NAME

6       RSA_sign, RSA_verify - RSA signatures
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SYNOPSIS

9        #include <openssl/rsa.h>
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11        int RSA_sign(int type, const unsigned char *m, unsigned int m_len,
12           unsigned char *sigret, unsigned int *siglen, RSA *rsa);
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14        int RSA_verify(int type, const unsigned char *m, unsigned int m_len,
15           unsigned char *sigbuf, unsigned int siglen, RSA *rsa);
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DESCRIPTION

18       RSA_sign() signs the message digest m of size m_len using the private
19       key rsa as specified in PKCS #1 v2.0. It stores the signature in sigret
20       and the signature size in siglen. sigret must point to RSA_size(rsa)
21       bytes of memory.  Note that PKCS #1 adds meta-data, placing limits on
22       the size of the key that can be used.  See RSA_private_encrypt(3) for
23       lower-level operations.
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25       type denotes the message digest algorithm that was used to generate m.
26       It usually is one of NID_sha1, NID_ripemd160 and NID_md5; see
27       objects(3) for details. If type is NID_md5_sha1, an SSL signature (MD5
28       and SHA1 message digests with PKCS #1 padding and no algorithm
29       identifier) is created.
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31       RSA_verify() verifies that the signature sigbuf of size siglen matches
32       a given message digest m of size m_len. type denotes the message digest
33       algorithm that was used to generate the signature.  rsa is the signer's
34       public key.
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RETURN VALUES

37       RSA_sign() returns 1 on success, 0 otherwise.  RSA_verify() returns 1
38       on successful verification, 0 otherwise.
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40       The error codes can be obtained by ERR_get_error(3).
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BUGS

43       Certain signatures with an improper algorithm identifier are accepted
44       for compatibility with SSLeay 0.4.5 :-)
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CONFORMING TO

47       SSL, PKCS #1 v2.0
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SEE ALSO

50       ERR_get_error(3), objects(3), rsa(3), RSA_private_encrypt(3),
51       RSA_public_decrypt(3)
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HISTORY

54       RSA_sign() and RSA_verify() are available in all versions of SSLeay and
55       OpenSSL.
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591.0.2o                            2020-01-28                       RSA_sign(3)
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