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trezor-firmware/base58.c
2014-06-07 14:05:59 +02:00

139 lines
3.7 KiB
C

/**
* Copyright (c) 2013-2014 Tomas Dzetkulic
* Copyright (c) 2013-2014 Pavol Rusnak
*
* 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.
*/
#include <string.h>
#include "base58.h"
#include "sha2.h"
int base58_encode_check(const uint8_t *data, int len, char *str)
{
int outlen;
switch (len) {
case 78: // xpub/xprv 78
outlen = 111;
break;
case 34: // WIF privkey 1+32+1
outlen = 52;
break;
case 21: // address 1+20
outlen = 34;
break;
default:
return 0;
}
uint8_t mydata[82], hash[32];
sha256_Raw(data, len, hash);
sha256_Raw(hash, 32, hash);
memcpy(mydata, data, len);
memcpy(mydata + len, hash, 4); // checksum
uint32_t rem, tmp;
const char code[] = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
int i, j;
for (j = 0; j < outlen; j++) {
rem = mydata[0] % 58;
mydata[0] /= 58;
for (i = 1; i < len + 4; i++) {
tmp = rem * 24 + mydata[i]; // 2^8 == 4*58 + 24
mydata[i] = rem * 4 + (tmp / 58);
rem = tmp % 58;
}
str[j] = code[rem];
}
// remove duplicite 1s at the end
while (outlen > 1 && str[outlen - 1] == code[0] && str[outlen - 2] == code[0]) {
outlen--;
}
str[outlen] = 0;
char s;
// reverse string
for (i = 0; i < outlen / 2; i++) {
s = str[i];
str[i] = str[outlen - 1 - i];
str[outlen - 1 - i] = s;
}
return outlen;
}
int base58_decode_check(const char *str, uint8_t *data)
{
const char decode[] = {
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3,
4, 5, 6, 7, 8, -1, -1, -1, -1, -1, -1, -1, 9, 10, 11,
12, 13, 14, 15, 16, -1, 17, 18, 19, 20, 21, -1, 22,
23, 24, 25, 26, 27, 28, 29, 30, 31, 32, -1, -1, -1,
-1, -1, -1, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42,
43, -1, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54,
55, 56, 57
};
int outlen;
switch (strlen(str)) {
case 111: // xpub/xprv
outlen = 78;
break;
case 52: // WIF privkey
outlen = 35;
break;
case 27: // address
case 28:
case 29:
case 30:
case 31:
case 32:
case 33:
case 34:
outlen = 21;
break;
default:
return 0;
}
uint8_t mydata[82], hash[32];
memset(mydata, 0, sizeof(mydata));
int i, j, k;
while (*str) {
i = *str;
if (i < 0 || i >= (int)sizeof(decode)) { // invalid character
return 0;
}
k = decode[i];
if (k == -1) { // invalid character
return 0;
}
for (j = outlen + 4 - 1; j >= 0; j--) {
k += mydata[j] * 58;
mydata[j] = k & 0xFF;
k >>= 8;
}
str++;
}
sha256_Raw(mydata, outlen, hash);
sha256_Raw(hash, 32, hash);
if (memcmp(mydata + outlen, hash, 4)) { // wrong checksum
return 0;
}
memcpy(data, mydata, outlen);
return outlen;
}