| /* |
| Name: rsamath.h |
| Purpose: Implements part of PKCS#1, v. 2.1, June 14, 2002 (RSA Labs) |
| Author: M. J. Fromberger |
| |
| Copyright (C) 2002-2008 Michael J. Fromberger, All Rights Reserved. |
| |
| Permission is hereby granted, free of charge, to any person obtaining a copy |
| of this software and associated documentation files (the "Software"), to deal |
| in the Software without restriction, including without limitation the rights |
| to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| copies of the Software, and to permit persons to whom the Software is |
| furnished to do so, subject to the following conditions: |
| |
| The above copyright notice and this permission notice shall be included in |
| all copies or substantial portions of the Software. |
| |
| THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
| SOFTWARE. |
| */ |
| |
| #ifndef RSAMATH_H_ |
| #define RSAMATH_H_ |
| |
| #include "imath.h" |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| /* Function to fill a buffer with nonzero random bytes */ |
| typedef void (*random_f)(unsigned char *, int); |
| |
| /* Convert integer to octet string, per PKCS#1 v.2.1 */ |
| mp_result rsa_i2osp(mp_int z, unsigned char *out, int len); |
| |
| /* Convert octet string to integer, per PKCS#1 v.2.1 */ |
| mp_result rsa_os2ip(mp_int z, unsigned char *in, int len); |
| |
| /* The following operations assume that you have converted your keys |
| and message data into mp_int values somehow. */ |
| |
| /* Primitive RSA encryption operation */ |
| mp_result rsa_rsaep(mp_int msg, mp_int exp, mp_int mod, mp_int cipher); |
| |
| /* Primitive RSA decryption operation */ |
| mp_result rsa_rsadp(mp_int cipher, mp_int exp, mp_int mod, mp_int msg); |
| |
| /* Primitive RSA signing operation */ |
| mp_result rsa_rsasp(mp_int msg, mp_int exp, mp_int mod, mp_int signature); |
| |
| /* Primitive RSA verification operation */ |
| mp_result rsa_rsavp(mp_int signature, mp_int exp, mp_int mod, mp_int msg); |
| |
| /* Compute the maximum length in bytes a message can have using PKCS#1 |
| v.1.5 encoding with the given modulus */ |
| int rsa_max_message_len(mp_int mod); |
| |
| /* Encode a raw message per PKCS#1 v.1.5 |
| buf - the buffer containing the message |
| msg_len - the length in bytes of the message |
| buf_len - the size in bytes of the buffer |
| tag - the message tag (nonzero byte) |
| filler - function to generate pseudorandom nonzero padding |
| |
| On input, the message is in the first msg_len bytes of the buffer; |
| on output, the contents of the buffer are replaced by the padded |
| message. If there is not enough room, MP_RANGE is returned. |
| */ |
| mp_result rsa_pkcs1v15_encode(unsigned char *buf, int msg_len, |
| int buf_len, int tag, random_f filler); |
| |
| /* Decode a PKCS#1 v.1.5 message back to its raw form |
| buf - the buffer containing the encoded message |
| buf_len - the length in bytes of the buffer |
| tag - the expected message tag (nonzero byte) |
| msg_len - on output, receives the length of the message content |
| |
| On output, the message is packed into the first msg_len bytes of |
| the buffer, and the rest of the buffer is zeroed. If the buffer is |
| not of the correct form, MP_UNDEF is returned and msg_len is undefined. |
| */ |
| mp_result rsa_pkcs1v15_decode(unsigned char *buf, int buf_len, |
| int tag, int *msg_len); |
| |
| #ifdef __cplusplus |
| } |
| #endif |
| #endif /* end RSAMATH_H_ */ |