+++ /dev/null
-
-/* rsa_oaep.c */
-/*
- This file is part of the ARM-Crypto-Lib.
- Copyright (C) 2006-2012 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 "memxor.h"
-#include "mgf1.h"
-#include "bigint.h"
-#include "rsa_basic.h"
-#include "rsa_oaep.h"
-
-#include "random_dummy.h"
-
-#include "hfal/hfal_sha1.h"
-
-#include "cli.h"
-#include "uart_lowlevel.h"
-
-mgf1_parameter_t mgf1_default_parameter = {
- &sha1_desc
-};
-
-rsa_oaep_parameter_t rsa_oaep_default_parameter = {
- mgf1,
- &sha1_desc,
- &mgf1_default_parameter
-};
-
-rsa_label_t rsa_oaep_default_label = {
- 0, NULL
-};
-
-uint8_t rsa_encrypt_oaep(void* dest, uint16_t* out_length,
- const void* src, uint16_t length_B,
- rsa_publickey_t* key, const rsa_oaep_parameter_t *p,
- const rsa_label_t* label, const void* seed){
-
- if(!p){
- p = &rsa_oaep_default_parameter;
- }
- if(!label){
- label = &rsa_oaep_default_label;
- }
- uint16_t hv_len = (hfal_hash_getHashsize(p->hf)+7)/8;
- if(length_B > bigint_length_B(key->modulus) - 2*hv_len - 2){
- /* message too long */
- return 1;
- }
- uint16_t buffer_len = bigint_length_B(key->modulus);
-/*
- cli_putstr("\r\n buffer_len = ");
- cli_hexdump_rev(&buffer_len, 2);
- cli_putstr("\r\n modulus_len = ");
- cli_hexdump_rev(&key->modulus->length_B, 2);
-*/
- uint8_t* buffer = (uint8_t*)dest;
- uint8_t off;
- /* the following needs some explanation:
- * off is the offset which is used for compensating the effect of
- * changeendian() when it operates on multi-byte words.
- * */
- off = (sizeof(bigint_word_t) -(bigint_get_first_set_bit(key->modulus)/8+1)%(sizeof(bigint_word_t)*8))
- % (sizeof(bigint_word_t));
- buffer += off;
- buffer_len -= off;
-// cli_putstr("\r\n off = ");
-// cli_hexdump_byte(off);
- uint8_t* seed_buffer = buffer + 1;
- uint16_t db_len = buffer_len - hv_len - 1;
- uint8_t* db = seed_buffer + hv_len;
- uint16_t maskbuffer_len = db_len>hv_len?db_len:hv_len;
- uint8_t maskbuffer[maskbuffer_len];
- bigint_t x;
-
- memset(dest, 0, seed_buffer - buffer + off);
- memset(db + hv_len, 0, db_len - hv_len - length_B -1);
- hfal_hash_mem(p->hf, db, label->label, label->length_b);
- db[db_len - length_B - 1] = 0x01;
- memcpy(db+db_len - length_B, src, length_B);
- if(seed){
- memcpy(seed_buffer, seed, hv_len);
- }else{
- /* generate random seed */
- if(!prng_get_byte){
- return 2; /* ERROR: no random generator specified */
- }
- uint16_t i;
- for(i=0; i<hv_len; ++i){
- seed_buffer[i] = prng_get_byte();
- }
- }
-// cli_putstr("\r\n msg (raw, pre-feistel):\r\n");
-// cli_hexdump_block(dest, bigint_length_B(key->modulus), 4, 16);
- p->mgf(maskbuffer, seed_buffer, hv_len, db_len, p->mgf_parameter);
- memxor(db, maskbuffer, db_len);
- p->mgf(maskbuffer, db, db_len, hv_len, p->mgf_parameter);
- memxor(seed_buffer, maskbuffer, hv_len);
-// cli_putstr("\r\n msg (raw, post-feistel):\r\n");
-// cli_hexdump_block(dest, bigint_length_B(key->modulus), 4, 16);
-
- x.wordv = dest;
- bigint_adjust(&x);
-
- rsa_os2ip(&x, NULL, bigint_length_B(key->modulus));
- rsa_enc(&x, key);
- rsa_i2osp(NULL, &x, out_length);
- return 0;
-}
-
-uint8_t rsa_decrypt_oaep(void* dest, uint16_t* out_length,
- const void* src, uint16_t length_B,
- rsa_privatekey_t* key, const rsa_oaep_parameter_t *p,
- const rsa_label_t* label, void* seed){
-
-// cli_putstr("\r\n -->rsa_decrypt_oaep()"); uart_flush(0);
- if(!label){
- label = &rsa_oaep_default_label;
- }
- if(!p){
- p = &rsa_oaep_default_parameter;
- }
- uint16_t x_len, data_len;
- bigint_t x;
- uint16_t hv_len = hfal_hash_getHashsize(p->hf)/8;
- uint8_t label_hv[hv_len];
- uint16_t msg_len = bigint_get_first_set_bit(key->modulus) / 8 + 1;
- uint16_t db_len = msg_len - hv_len - 1;
- uint8_t maskbuffer[db_len>hv_len?db_len:hv_len];
-
- uint8_t *seed_buffer = dest;
- uint8_t *db_buffer = seed_buffer + hv_len;
-
- x_len = bigint_get_first_set_bit(key->modulus)/8;
- memset(dest, 0, bigint_length_B(key->modulus) - length_B);
- memcpy((uint8_t*)dest + bigint_length_B(key->modulus) - length_B, src, length_B);
-
-// cli_putc('a'); uart_flush(0);
-
- x.wordv = dest;
- x.length_B = key->modulus->length_B;
- x.info = 0;
- bigint_adjust(&x);
-
-
-// cli_putc('b'); uart_flush(0);
- rsa_os2ip(&x, NULL, bigint_length_B(key->modulus));
-// cli_putc('c'); uart_flush(0);
- rsa_dec(&x, key);
-// cli_putc('d'); uart_flush(0);
- rsa_i2osp(NULL, &x, &data_len);
-
-// cli_putstr("\r\n msg (raw, pre-move):\r\n");
-// cli_hexdump_block(dest, bigint_length_B(key->modulus), 4, 16);
-
- if(data_len > x_len){
- return 7;
- }
-/*
- cli_putstr("\r\n moving some bytes; x_len = ");
- cli_hexdump_rev(&x_len, 2);
- cli_putstr(" data_len = ");
- cli_hexdump_rev(&data_len, 2);
- uart_flush(0);
-*/
- if(x_len != data_len){
- memmove((uint8_t*)dest + x_len - data_len, dest, data_len);
-// cli_putstr(" (oh, not dead yet?!)");
-// uart_flush(0);
- memset(dest, 0, x_len - data_len);
- }
-
- hfal_hash_mem(p->hf, label_hv, label->label, label->length_b);
-/*
- cli_putstr("\r\n msg (raw, pre-feistel):\r\n");
- cli_hexdump_block(seed_buffer, bigint_length_B(key->modulus), 4, 16);
- uart_flush(0);
-*/
- p->mgf(maskbuffer, db_buffer, db_len, hv_len, p->mgf_parameter);
- memxor(seed_buffer, maskbuffer, hv_len);
- p->mgf(maskbuffer, seed_buffer, hv_len, db_len, p->mgf_parameter);
- memxor(db_buffer, maskbuffer, db_len);
-
- if(memcmp(label_hv, db_buffer, hv_len)){
-// cli_putstr("\r\nDBG: DB:\r\n");
-// cli_hexdump_block(db_buffer, db_len, 4, 16);
- return 2;
- }
-
- uint16_t ps_len=0;
- while(db_buffer[hv_len + ps_len++] == 0)
- ;
-
- --ps_len;
- if(db_buffer[hv_len + ps_len] != 1){
- return 3;
- }
-
- if(seed){
- memcpy(seed, seed_buffer, hv_len);
- }
-
- msg_len = db_len - hv_len - 1 - ps_len;
- memmove(dest, db_buffer + hv_len + ps_len + 1, msg_len);
-
- *out_length = msg_len;
-
- return 0;
-}
-
-
projects / arm-crypto-lib.git / blobdiff