/** * Copyright (c) 2012-2014 Luke Dashjr * 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 <stdbool.h> #include <sys/types.h> #include "base58.h" #include "sha2.h" #include "macros.h" static const int8_t b58digits_map[] = { -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,-1,-1,-1,-1,-1, }; bool b58tobin(void *bin, size_t *binszp, const char *b58) { size_t binsz = *binszp; const unsigned char *b58u = (void*)b58; unsigned char *binu = bin; size_t outisz = (binsz + 3) / 4; uint32_t outi[outisz]; uint64_t t; uint32_t c; size_t i, j; uint8_t bytesleft = binsz % 4; uint32_t zeromask = bytesleft ? (0xffffffff << (bytesleft * 8)) : 0; unsigned zerocount = 0; size_t b58sz; b58sz = strlen(b58); memset(outi, 0, outisz * sizeof(*outi)); // Leading zeros, just count for (i = 0; i < b58sz && !b58digits_map[b58u[i]]; ++i) ++zerocount; for ( ; i < b58sz; ++i) { if (b58u[i] & 0x80) // High-bit set on invalid digit return false; if (b58digits_map[b58u[i]] == -1) // Invalid base58 digit return false; c = (unsigned)b58digits_map[b58u[i]]; for (j = outisz; j--; ) { t = ((uint64_t)outi[j]) * 58 + c; c = (t & 0x3f00000000) >> 32; outi[j] = t & 0xffffffff; } if (c) // Output number too big (carry to the next int32) return false; if (outi[0] & zeromask) // Output number too big (last int32 filled too far) return false; } j = 0; switch (bytesleft) { case 3: *(binu++) = (outi[0] & 0xff0000) >> 16; case 2: *(binu++) = (outi[0] & 0xff00) >> 8; case 1: *(binu++) = (outi[0] & 0xff); ++j; default: break; } for (; j < outisz; ++j) { *(binu++) = (outi[j] >> 0x18) & 0xff; *(binu++) = (outi[j] >> 0x10) & 0xff; *(binu++) = (outi[j] >> 8) & 0xff; *(binu++) = (outi[j] >> 0) & 0xff; } // Count canonical base58 byte count binu = bin; for (i = 0; i < binsz; ++i) { if (binu[i]) break; --*binszp; } *binszp += zerocount; return true; } int b58check(const void *bin, size_t binsz, const char *base58str) { unsigned char buf[32]; const uint8_t *binc = bin; unsigned i; if (binsz < 4) return -4; sha256_Raw(bin, binsz - 4, buf); sha256_Raw(buf, 32, buf); if (memcmp(&binc[binsz - 4], buf, 4)) return -1; // Check number of zeros is correct AFTER verifying checksum (to avoid possibility of accessing base58str beyond the end) for (i = 0; binc[i] == '\0' && base58str[i] == '1'; ++i) {} // Just finding the end of zeros, nothing to do in loop if (binc[i] == '\0' || base58str[i] == '1') return -3; return binc[0]; } static const char b58digits_ordered[] = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"; bool b58enc(char *b58, size_t *b58sz, const void *data, size_t binsz) { const uint8_t *bin = data; int carry; ssize_t i, j, high, zcount = 0; size_t size; while (zcount < (ssize_t)binsz && !bin[zcount]) ++zcount; size = (binsz - zcount) * 138 / 100 + 1; uint8_t buf[size]; memset(buf, 0, size); for (i = zcount, high = size - 1; i < (ssize_t)binsz; ++i, high = j) { for (carry = bin[i], j = size - 1; (j > high) || carry; --j) { carry += 256 * buf[j]; buf[j] = carry % 58; carry /= 58; } } for (j = 0; j < (ssize_t)size && !buf[j]; ++j); if (*b58sz <= zcount + size - j) { *b58sz = zcount + size - j + 1; return false; } if (zcount) memset(b58, '1', zcount); for (i = zcount; j < (ssize_t)size; ++i, ++j) b58[i] = b58digits_ordered[buf[j]]; b58[i] = '\0'; *b58sz = i + 1; return true; } int base58_encode_check(const uint8_t *data, int datalen, char *str, int strsize) { if (datalen > 128) { return 0; } uint8_t buf[datalen + 32]; uint8_t *hash = buf + datalen; memcpy(buf, data, datalen); sha256_Raw(data, datalen, hash); sha256_Raw(hash, 32, hash); size_t res = strsize; bool success = b58enc(str, &res, buf, datalen + 4); MEMSET_BZERO(buf, sizeof(buf)); return success ? res : 0; } int base58_decode_check(const char *str, uint8_t *data, int datalen) { if (datalen > 128) { return 0; } uint8_t d[datalen + 4]; size_t res = datalen + 4; if (b58tobin(d, &res, str) != true) { return 0; } if (res != (size_t)datalen + 4) { return 0; } if (b58check(d, res, str) < 0) { return 0; } memcpy(data, d, datalen); return datalen; }