RSA_PRIVATE_ENCRYPT(3) | Library Functions Manual | RSA_PRIVATE_ENCRYPT(3) |
RSA_private_encrypt
,
RSA_public_decrypt
— low
level signature operations
#include
<openssl/rsa.h>
int
RSA_private_encrypt
(int flen,
const unsigned char *from, unsigned
char *to, RSA *rsa, int
padding);
int
RSA_public_decrypt
(int flen,
const unsigned char *from, unsigned
char *to, RSA *rsa, int
padding);
These functions handle RSA signatures at a low level.
RSA_private_encrypt
() signs the
flen bytes at from (usually a
message digest with an algorithm identifier) using the private key
rsa and stores the signature in
to. to must point to
RSA_size
(rsa) bytes of
memory.
padding denotes one of the following modes:
RSA_PKCS1_PADDING
RSA_NO_PADDING
RSA_public_decrypt
() recovers the message
digest from the flen bytes long signature at
from using the signer's public key
rsa. to must point to a memory
section large enough to hold the message digest (which is smaller than
RSA_size
(rsa) - 11).
padding is the padding mode that was used to sign the
data.
RSA_private_encrypt
() returns the size of
the signature (i.e.
RSA_size
(rsa)).
RSA_public_decrypt
() returns the size of the
recovered message digest.
On error, -1 is returned; the error codes can be obtained by ERR_get_error(3).
RSA_meth_set_priv_enc(3), RSA_new(3), RSA_sign(3), RSA_verify(3)
RSA_private_encrypt
() and
RSA_public_decrypt
() appeared in SSLeay 0.4 or
earlier and have been available since OpenBSD
2.4.
RSA_NO_PADDING
is available since SSLeay
0.9.0.
June 10, 2019 | OpenBSD-current |