NAME¶
RSA_padding_add_PKCS1_type_1, RSA_padding_check_PKCS1_type_1,
RSA_padding_add_PKCS1_type_2, RSA_padding_check_PKCS1_type_2,
RSA_padding_add_PKCS1_OAEP, RSA_padding_check_PKCS1_OAEP,
RSA_padding_add_SSLv23, RSA_padding_check_SSLv23, RSA_padding_add_none,
RSA_padding_check_none - asymmetric encryption padding
SYNOPSIS¶
#include <openssl/rsa.h>
int RSA_padding_add_PKCS1_type_1(unsigned char *to, int tlen,
unsigned char *f, int fl);
int RSA_padding_check_PKCS1_type_1(unsigned char *to, int tlen,
unsigned char *f, int fl, int rsa_len);
int RSA_padding_add_PKCS1_type_2(unsigned char *to, int tlen,
unsigned char *f, int fl);
int RSA_padding_check_PKCS1_type_2(unsigned char *to, int tlen,
unsigned char *f, int fl, int rsa_len);
int RSA_padding_add_PKCS1_OAEP(unsigned char *to, int tlen,
unsigned char *f, int fl, unsigned char *p, int pl);
int RSA_padding_check_PKCS1_OAEP(unsigned char *to, int tlen,
unsigned char *f, int fl, int rsa_len, unsigned char *p, int pl);
int RSA_padding_add_SSLv23(unsigned char *to, int tlen,
unsigned char *f, int fl);
int RSA_padding_check_SSLv23(unsigned char *to, int tlen,
unsigned char *f, int fl, int rsa_len);
int RSA_padding_add_none(unsigned char *to, int tlen,
unsigned char *f, int fl);
int RSA_padding_check_none(unsigned char *to, int tlen,
unsigned char *f, int fl, int rsa_len);
DESCRIPTION¶
The
RSA_padding_xxx_xxx() functions are called from the RSA encrypt,
decrypt, sign and verify functions. Normally they should not be called from
application programs.
However, they can also be called directly to implement padding for other
asymmetric ciphers.
RSA_padding_add_PKCS1_OAEP() and
RSA_padding_check_PKCS1_OAEP() may be used in an application combined
with
RSA_NO_PADDING in order to implement OAEP with an encoding
parameter.
RSA_padding_add_xxx() encodes
fl bytes from
f so as to fit
into
tlen bytes and stores the result at
to. An error occurs if
fl does not meet the size requirements of the encoding method.
The following encoding methods are implemented:
- PKCS1_type_1
- PKCS #1 v2.0 EMSA-PKCS1-v1_5 (PKCS #1 v1.5 block type 1); used for
signatures
- PKCS1_type_2
- PKCS #1 v2.0 EME-PKCS1-v1_5 (PKCS #1 v1.5 block type 2)
- PKCS1_OAEP
- PKCS #1 v2.0 EME-OAEP
- SSLv23
- PKCS #1 EME-PKCS1-v1_5 with SSL-specific modification
- none
- simply copy the data
The random number generator must be seeded prior to calling
RSA_padding_add_xxx().
RSA_padding_check_xxx() verifies that the
fl bytes at
f
contain a valid encoding for a
rsa_len byte RSA key in the respective
encoding method and stores the recovered data of at most
tlen bytes
(for
RSA_NO_PADDING: of size
tlen) at
to.
For
RSA_padding_xxx_OAEP(),
p points to the encoding parameter of
length
pl.
p may be
NULL if
pl is 0.
RETURN VALUES¶
The
RSA_padding_add_xxx() functions return 1 on success, 0 on error. The
RSA_padding_check_xxx() functions return the length of the recovered
data, -1 on error. Error codes can be obtained by calling
ERR_get_error(3).
SEE ALSO¶
RSA_public_encrypt(3),
RSA_private_decrypt(3),
RSA_sign(3),
RSA_verify(3)
HISTORY¶
RSA_padding_add_PKCS1_type_1(),
RSA_padding_check_PKCS1_type_1(),
RSA_padding_add_PKCS1_type_2(),
RSA_padding_check_PKCS1_type_2(),
RSA_padding_add_SSLv23(),
RSA_padding_check_SSLv23(),
RSA_padding_add_none() and
RSA_padding_check_none() appeared in SSLeay 0.9.0.
RSA_padding_add_PKCS1_OAEP() and
RSA_padding_check_PKCS1_OAEP()
were added in OpenSSL 0.9.2b.