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trezor-firmware/crypto/monero/base58.c
2019-04-15 19:14:52 +02:00

244 lines
7.2 KiB
C

// Copyright (c) 2014-2018, The Monero Project
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification, are
// permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this list of
// conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright notice, this list
// of conditions and the following disclaimer in the documentation and/or other
// materials provided with the distribution.
//
// 3. Neither the name of the copyright holder nor the names of its contributors may be
// used to endorse or promote products derived from this software without specific
// prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers
#include <assert.h>
#include <string.h>
#include <stdbool.h>
#include <sys/types.h>
#include "base58.h"
#include "int-util.h"
#include "sha2.h"
#include "../base58.h"
const size_t alphabet_size = 58; // sizeof(b58digits_ordered) - 1;
const size_t encoded_block_sizes[] = {0, 2, 3, 5, 6, 7, 9, 10, 11};
const size_t full_block_size = sizeof(encoded_block_sizes) / sizeof(encoded_block_sizes[0]) - 1;
const size_t full_encoded_block_size = 11; // encoded_block_sizes[full_block_size];
const size_t addr_checksum_size = 4;
const int decoded_block_sizes[] = {0, -1, 1, 2, -1, 3, 4, 5, -1, 6, 7, 8};
#define reverse_alphabet(letter) ((int8_t) b58digits_map[(int)letter])
uint64_t uint_8be_to_64(const uint8_t* data, size_t size)
{
assert(1 <= size && size <= sizeof(uint64_t));
uint64_t res = 0;
switch (9 - size)
{
case 1: res |= *data++; /* FALLTHRU */
case 2: res <<= 8; res |= *data++; /* FALLTHRU */
case 3: res <<= 8; res |= *data++; /* FALLTHRU */
case 4: res <<= 8; res |= *data++; /* FALLTHRU */
case 5: res <<= 8; res |= *data++; /* FALLTHRU */
case 6: res <<= 8; res |= *data++; /* FALLTHRU */
case 7: res <<= 8; res |= *data++; /* FALLTHRU */
case 8: res <<= 8; res |= *data; break;
default: assert(false);
}
return res;
}
void uint_64_to_8be(uint64_t num, size_t size, uint8_t* data)
{
assert(1 <= size && size <= sizeof(uint64_t));
uint64_t num_be = SWAP64(num);
memcpy(data, (uint8_t*)(&num_be) + sizeof(uint64_t) - size, size);
}
void encode_block(const char* block, size_t size, char* res)
{
assert(1 <= size && size <= full_block_size);
uint64_t num = uint_8be_to_64((uint8_t*)(block), size);
int i = ((int)(encoded_block_sizes[size])) - 1;
while (0 <= i)
{
uint64_t remainder = num % alphabet_size;
num /= alphabet_size;
res[i] = b58digits_ordered[remainder];
--i;
}
}
bool decode_block(const char* block, size_t size, char* res)
{
assert(1 <= size && size <= full_encoded_block_size);
int res_size = decoded_block_sizes[size];
if (res_size <= 0)
return false; // Invalid block size
uint64_t res_num = 0;
uint64_t order = 1;
for (size_t i = size - 1; i < size; --i)
{
int digit = reverse_alphabet(block[i]);
if (digit < 0)
return false; // Invalid symbol
uint64_t product_hi;
uint64_t tmp = res_num + mul128(order, (uint64_t) digit, &product_hi);
if (tmp < res_num || 0 != product_hi)
return false; // Overflow
res_num = tmp;
order *= alphabet_size; // Never overflows, 58^10 < 2^64
}
if ((size_t)res_size < full_block_size && (UINT64_C(1) << (8 * res_size)) <= res_num)
return false; // Overflow
uint_64_to_8be(res_num, res_size, (uint8_t*)(res));
return true;
}
bool xmr_base58_encode(char *b58, size_t *b58sz, const void *data, size_t binsz)
{
if (binsz==0)
return true;
const char * data_bin = data;
size_t full_block_count = binsz / full_block_size;
size_t last_block_size = binsz % full_block_size;
size_t res_size = full_block_count * full_encoded_block_size + encoded_block_sizes[last_block_size];
if (b58sz){
if (res_size >= *b58sz){
return false;
}
*b58sz = res_size;
}
for (size_t i = 0; i < full_block_count; ++i)
{
encode_block(data_bin + i * full_block_size, full_block_size, b58 + i * full_encoded_block_size);
}
if (0 < last_block_size)
{
encode_block(data_bin + full_block_count * full_block_size, last_block_size, b58 + full_block_count * full_encoded_block_size);
}
return true;
}
bool xmr_base58_decode(const char *b58, size_t b58sz, void *data, size_t *binsz)
{
if (b58sz == 0) {
*binsz = 0;
return true;
}
size_t full_block_count = b58sz / full_encoded_block_size;
size_t last_block_size = b58sz % full_encoded_block_size;
int last_block_decoded_size = decoded_block_sizes[last_block_size];
if (last_block_decoded_size < 0) {
*binsz = 0;
return false; // Invalid enc length
}
size_t data_size = full_block_count * full_block_size + last_block_decoded_size;
if (*binsz < data_size){
*binsz = 0;
return false;
}
char * data_bin = data;
for (size_t i = 0; i < full_block_count; ++i)
{
if (!decode_block(b58 + i * full_encoded_block_size, full_encoded_block_size, data_bin + i * full_block_size))
return false;
}
if (0 < last_block_size)
{
if (!decode_block(b58 + full_block_count * full_encoded_block_size, last_block_size,
data_bin + full_block_count * full_block_size))
return false;
}
return true;
}
int xmr_base58_addr_encode_check(uint64_t tag, const uint8_t *data, size_t binsz, char *b58, size_t b58sz)
{
if (binsz > 128 || tag > 127) { // tag varint
return false;
}
size_t b58size = b58sz;
uint8_t buf[binsz + 1 + HASHER_DIGEST_LENGTH];
uint8_t *hash = buf + binsz + 1;
buf[0] = (uint8_t) tag;
memcpy(buf + 1, data, binsz);
hasher_Raw(HASHER_SHA3K, buf, binsz + 1, hash);
bool r = xmr_base58_encode(b58, &b58size, buf, binsz + 1 + addr_checksum_size);
return (int) (!r ? 0 : b58size);
}
int xmr_base58_addr_decode_check(const char *addr, size_t sz, uint64_t *tag, void *data, size_t datalen)
{
size_t buflen = 1 + 64 + addr_checksum_size;
uint8_t buf[buflen];
uint8_t hash[HASHER_DIGEST_LENGTH];
if (!xmr_base58_decode(addr, sz, buf, &buflen)){
return 0;
}
size_t res_size = buflen - addr_checksum_size - 1;
if (datalen < res_size){
return 0;
}
if (buflen <= addr_checksum_size+1) {
return 0;
}
hasher_Raw(HASHER_SHA3K, buf, buflen - addr_checksum_size, hash);
if (memcmp(hash, buf + buflen - addr_checksum_size, addr_checksum_size) != 0){
return 0;
}
*tag = buf[0];
if (*tag > 127){
return false; // varint
}
memcpy(data, buf+1, res_size);
return (int) res_size;
}