152 lines
3.8 KiB
C
152 lines
3.8 KiB
C
/* rsa_basic.c */
|
|
/*
|
|
This file is part of the ARM-Crypto-Lib.
|
|
Copyright (C) 2006-2011 Daniel Otte (daniel.otte@rub.de)
|
|
|
|
This program is free software: you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation, either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#include <stdint.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include "bigint.h"
|
|
#include "bigint_io.h"
|
|
#include "rsa_basic.h"
|
|
|
|
#define DEBUG 0
|
|
|
|
#if DEBUG
|
|
#include "cli.h"
|
|
#include "uart_lowlevel.h"
|
|
#endif
|
|
|
|
void rsa_enc(bigint_t* data, rsa_publickey_t* key){
|
|
/*
|
|
cli_putstr("\r\n -->rsa_enc()\r\n m = ");
|
|
bigint_print_hex(data);
|
|
cli_putstr("\r\n e = ");
|
|
bigint_print_hex(key->exponent);
|
|
cli_putstr("\r\n n = ");
|
|
bigint_print_hex(key->modulus);
|
|
*/
|
|
bigint_expmod_u(data, data, key->exponent, key->modulus);
|
|
}
|
|
|
|
/*
|
|
(p,q,dp,dq,qinv)
|
|
m1 = c**dp % p
|
|
m2 = c**dq % q
|
|
h = (m1 - m2) * qinv % p
|
|
m = m2 + q * h
|
|
*/
|
|
|
|
uint8_t rsa_dec_crt_mono(bigint_t* data, rsa_privatekey_t* key){
|
|
bigint_t m1, m2;
|
|
m1.wordv = malloc(key->components[0]->length_B * sizeof(bigint_word_t));
|
|
m2.wordv = malloc(key->components[1]->length_B * sizeof(bigint_word_t));
|
|
if(!m1.wordv || !m2.wordv){
|
|
#if DEBUG
|
|
cli_putstr("\r\nERROR: OOM!");
|
|
#endif
|
|
free(m1.wordv);
|
|
free(m2.wordv);
|
|
return 1;
|
|
}
|
|
#if DEBUG
|
|
cli_putstr("\r\nDBG: expmod m1 ...");
|
|
#endif
|
|
bigint_expmod_u(&m1, data, key->components[2], key->components[0]);
|
|
#if DEBUG
|
|
cli_putstr("expmod m2 ...");
|
|
#endif
|
|
bigint_expmod_u(&m2, data, key->components[3], key->components[1]);
|
|
bigint_sub_s(&m1, &m1, &m2);
|
|
while(BIGINT_NEG_MASK & m1.info){
|
|
bigint_add_s(&m1, &m1, key->components[0]);
|
|
}
|
|
|
|
#if DEBUG
|
|
cli_putstr("\r\nDBG: reduce-mul ...");
|
|
#endif
|
|
bigint_reduce(&m1, key->components[0]);
|
|
bigint_mul_u(data, &m1, key->components[4]);
|
|
bigint_reduce(data, key->components[0]);
|
|
bigint_mul_u(data, data, key->components[1]);
|
|
bigint_add_u(data, data, &m2);
|
|
free(m1.wordv);
|
|
free(m2.wordv);
|
|
return 0;
|
|
}
|
|
|
|
uint8_t rsa_dec(bigint_t* data, rsa_privatekey_t* key){
|
|
if(key->n == 1){
|
|
bigint_expmod_u(data, data, key->components[0], key->modulus);
|
|
return 0;
|
|
}
|
|
if(key->n == 5){
|
|
if (rsa_dec_crt_mono(data, key)){
|
|
return 3;
|
|
}
|
|
return 0;
|
|
}
|
|
if(key->n<8 || (key->n-5)%3 != 0){
|
|
return 1;
|
|
}
|
|
//rsa_dec_crt_multi(data, key, (key->n-5)/3);
|
|
return 2;
|
|
}
|
|
|
|
void rsa_os2ip(bigint_t* dest, const void* data, uint32_t length_B){
|
|
uint8_t off;
|
|
off = length_B % sizeof(bigint_word_t);
|
|
if(!data){
|
|
if(off){
|
|
dest->wordv = realloc(dest->wordv, length_B + sizeof(bigint_word_t) - off);
|
|
memmove((uint8_t*)dest->wordv+off, dest->wordv, length_B);
|
|
memset(dest->wordv, 0, off);
|
|
}
|
|
}else{
|
|
if(off){
|
|
memcpy((uint8_t*)dest->wordv + off, data, length_B);
|
|
memset(dest, 0, off);
|
|
}else{
|
|
memcpy(dest->wordv, data, length_B);
|
|
}
|
|
}
|
|
dest->length_B = (length_B + sizeof(bigint_word_t) - 1) / sizeof(bigint_word_t);
|
|
bigint_changeendianess(dest);
|
|
bigint_adjust(dest);
|
|
}
|
|
|
|
void rsa_i2osp(void* dest, bigint_t* src, uint16_t* out_length_B){
|
|
*out_length_B = bigint_get_first_set_bit(src) / 8 + 1;
|
|
if(dest){
|
|
uint16_t i;
|
|
for(i=*out_length_B; i>0; --i){
|
|
*((uint8_t*)dest) = ((uint8_t*)src->wordv)[i-1];
|
|
dest = (uint8_t*)dest + 1;
|
|
}
|
|
}else{
|
|
uint8_t off;
|
|
bigint_changeendianess(src);
|
|
bigint_adjust(src);
|
|
|
|
off = bigint_get_last_set_bit(src)/8;
|
|
if(off){
|
|
memmove(src->wordv, (uint8_t*)src->wordv+off, *out_length_B);
|
|
}
|
|
}
|
|
}
|
|
|