251 lines
6.1 KiB
C
251 lines
6.1 KiB
C
/* rsa_basic.c */
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/*
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This file is part of the ARM-Crypto-Lib.
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Copyright (C) 2006-2015 Daniel Otte (bg@nerilex.org)
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <stdint.h>
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#include <stdlib.h>
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#include <string.h>
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#include "bigint.h"
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#include "bigint_io.h"
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#include "rsa_basic.h"
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#define DEBUG 0
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#if DEBUG
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#include "cli.h"
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#include <stdio.h>
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#endif
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void rsa_enc(bigint_t *data, const rsa_publickey_t *key){
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/*
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cli_putstr_P(PSTR("\r\n -->rsa_enc()\r\n m = "));
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bigint_print_hex(data);
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cli_putstr_P(PSTR("\r\n e = "));
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bigint_print_hex(key->exponent);
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cli_putstr_P(PSTR("\r\n n = "));
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bigint_print_hex(key->modulus);
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*/
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bigint_expmod_u(data, data, &key->exponent, &key->modulus);
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}
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/*
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(p,q,dp,dq,qinv)
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m1 = c**dp % p
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m2 = c**dq % q
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h = (m1 - m2) * qinv % p
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m = m2 + q * h
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*/
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uint8_t rsa_dec_crt_mono(bigint_t *data, const rsa_privatekey_t *key){
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bigint_t m1, m2;
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m1.wordv = malloc((key->components[0].length_W /* + 1 */) * sizeof(bigint_word_t));
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m2.wordv = malloc((key->components[1].length_W /* + 1 */) * sizeof(bigint_word_t));
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if(!m1.wordv || !m2.wordv){
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#if DEBUG
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cli_putstr_P(PSTR("\r\nERROR: OOM!"));
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#endif
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free(m1.wordv);
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free(m2.wordv);
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return 1;
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}
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#if DEBUG
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cli_putstr_P(PSTR("\r\nDBG: expmod m1 ..."));
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cli_putstr_P(PSTR("\r\nexpmod("));
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bigint_print_hex(data);
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cli_putc(',');
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bigint_print_hex(&(key->components[2]));
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cli_putc(',');
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bigint_print_hex(&(key->components[0]));
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cli_putstr_P(PSTR(") = "));
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#endif
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bigint_expmod_u(&m1, data, &(key->components[2]), &(key->components[0]));
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#if DEBUG
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bigint_print_hex(&m1);
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cli_putstr_P(PSTR("expmod m2 ..."));
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cli_putstr_P(PSTR("\r\nexpmod("));
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bigint_print_hex(data);
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cli_putc(',');
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bigint_print_hex(&(key->components[3]));
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cli_putc(',');
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bigint_print_hex(&(key->components[1]));
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cli_putstr_P(PSTR(") = "));
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#endif
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bigint_expmod_u(&m2, data, &(key->components[3]), &(key->components[1]));
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#if DEBUG
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bigint_print_hex(&m2);
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cli_putstr_P(PSTR("\r\nDBG: sub ..."));
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cli_putstr_P(PSTR("\r\nsub("));
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bigint_print_hex(&m1);
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cli_putc(',');
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bigint_print_hex(&m2);
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cli_putstr_P(PSTR(") = "));
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#endif
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bigint_sub_s(&m1, &m1, &m2);
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#if DEBUG
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bigint_print_hex(&m1);
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#endif
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while(BIGINT_NEG_MASK & m1.info){
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#if DEBUG
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cli_putstr_P(PSTR("\r\nDBG: adding "));
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bigint_print_hex(&key->components[0]);
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cli_putstr_P(PSTR("\r\nDBG: to "));
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bigint_print_hex(&m1);
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#endif
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bigint_add_s(&m1, &m1, &(key->components[0]));
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}
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#if DEBUG
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cli_putstr_P(PSTR("\r\nDBG: reduce-mul ..."));
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cli_putstr_P(PSTR("\r\nreduce("));
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bigint_print_hex(&m1);
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cli_putc(',');
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bigint_print_hex(&(key->components[0]));
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cli_putstr_P(PSTR(") = "));
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#endif
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bigint_reduce(&m1, &(key->components[0]));
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#if DEBUG
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bigint_print_hex(&m1);
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cli_putstr_P(PSTR("\r\nmul("));
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bigint_print_hex(&m1);
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cli_putc(',');
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bigint_print_hex(&(key->components[4]));
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cli_putstr_P(PSTR(") = "));
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#endif
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bigint_mul_u(data, &m1, &(key->components[4]));
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#if DEBUG
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bigint_print_hex(data);
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cli_putstr_P(PSTR("\r\nreduce("));
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bigint_print_hex(data);
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cli_putc(',');
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bigint_print_hex(&(key->components[0]));
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cli_putstr_P(PSTR(") = "));
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#endif
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bigint_reduce(data, &(key->components[0]));
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#if DEBUG
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bigint_print_hex(data);
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cli_putstr_P(PSTR("\r\nmul("));
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bigint_print_hex(data);
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cli_putc(',');
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bigint_print_hex(&(key->components[1]));
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cli_putstr_P(PSTR(") = "));
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#endif
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bigint_mul_u(data, data, &(key->components[1]));
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#if DEBUG
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bigint_print_hex(data);
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cli_putstr_P(PSTR("\r\nadd("));
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bigint_print_hex(data);
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cli_putc(',');
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bigint_print_hex(&m2);
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cli_putstr_P(PSTR(") = "));
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#endif
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bigint_add_u(data, data, &m2);
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#if DEBUG
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bigint_print_hex(data);
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#endif
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free(m2.wordv);
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free(m1.wordv);
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return 0;
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}
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uint8_t rsa_dec(bigint_t *data, const rsa_privatekey_t *key){
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if(key->n == 1){
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bigint_expmod_u(data, data, &(key->components[0]), &key->modulus);
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return 0;
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}
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if(key->n == 5){
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if (rsa_dec_crt_mono(data, key)){
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return 3;
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}
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return 0;
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}
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if(key->n<8 || (key->n-5)%3 != 0){
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return 1;
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}
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//rsa_dec_crt_multi(data, key, (key->n-5)/3);
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return 2;
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}
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void rsa_os2ip(bigint_t *dest, const void *data, uint32_t length_B){
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#if BIGINT_WORD_SIZE == 8
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if(data){
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memcpy(dest->wordv, data, length_B);
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}
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dest->length_W = length_B;
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#else
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uint8_t off;
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off = (sizeof(bigint_word_t) - length_B % sizeof(bigint_word_t)) % sizeof(bigint_word_t);
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#if DEBUG
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printf("\r\nDBG: off = 0x%02x", off);
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#endif
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if (!data) {
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if (off) {
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dest->wordv = realloc(dest->wordv, length_B + sizeof(bigint_word_t) - off);
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memmove((uint8_t*)dest->wordv + off, dest->wordv, length_B);
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memset(dest->wordv, 0, off);
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}
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}else{
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memcpy((uint8_t*)dest->wordv + off, data, length_B);
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if(off){
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memset(dest->wordv, 0, off);
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}
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}
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dest->length_W = (length_B + off) / sizeof(bigint_word_t);
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#if DEBUG
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printf("\r\nDBG: dest->length_W = %u", dest->length_W);
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#endif
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#endif
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dest->info = 0;
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bigint_changeendianess(dest);
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bigint_adjust(dest);
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}
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void rsa_i2osp(void *dest, bigint_t *src, uint16_t *out_length_B){
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#if BIGINT_WORD_SIZE == 8
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if(dest){
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uint8_t *e = src->wordv + src->length_W;
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uint16_t i;
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for(i=src->length_W; i>0; --i){
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*((uint8_t*)dest) = *--e;
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dest = (uint8_t*)dest + 1;
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}
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}else{
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bigint_changeendianess(src);
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}
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*out_length_B = src->length_W;
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#else
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*out_length_B = bigint_get_first_set_bit(src) / 8 + 1;
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if(dest){
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uint16_t i;
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for(i=*out_length_B; i>0; --i){
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*((uint8_t*)dest) = ((uint8_t*)src->wordv)[i-1];
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dest = (uint8_t*)dest + 1;
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}
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}else{
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uint8_t off;
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bigint_changeendianess(src);
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bigint_adjust(src);
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off = bigint_get_last_set_bit(src)/8;
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if(off){
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memmove(src->wordv, (uint8_t*)src->wordv+off, *out_length_B);
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}
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}
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#endif
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}
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