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).
The padding argument was added in SSLeay
0.8. RSA_NO_PADDING
is available since SSLeay
0.9.0.
March 25, 2017 | OpenBSD-6.1 |