diff --git a/crypto/base58.c b/crypto/base58.c new file mode 100644 index 00000000..e9f85f2a --- /dev/null +++ b/crypto/base58.c @@ -0,0 +1,150 @@ +/* + * Copyright 2012-2014 Luke Dashjr + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the standard MIT license. See COPYING for more details. + */ + +#include +#include +#include +#include +#include + +#include "base58.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 base58_decode(const char *b58, size_t b58sz, void *bin, size_t *binszp) +{ + 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; + + if (!b58sz) + b58sz = strlen(b58); + + memset(outi, 0, outisz * sizeof(*outi)); + + // Leading zeros, just count + for (i = 0; i < b58sz && b58u[i] == '1'; ++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; +} + +static const char b58digits_ordered[] = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"; + +bool base58_encode(const void *data, size_t binsz, char *b58, size_t *b58sz) +{ + const uint8_t *bin = data; + int carry; + ssize_t i, j, high, zcount = 0; + size_t size; + + while (zcount < 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 < 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 < 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 < size; ++i, ++j) + b58[i] = b58digits_ordered[buf[j]]; + b58[i] = '\0'; + *b58sz = i + 1; + + return true; +} + diff --git a/include/openssl/base58.h b/include/openssl/base58.h new file mode 100644 index 00000000..2adbb2ba --- /dev/null +++ b/include/openssl/base58.h @@ -0,0 +1,14 @@ +#ifndef LIBBASE58_H +#define LIBBASE58_H + +#include +#include +#include + +bool base58_decode(const char *b58, size_t b58sz, void *bin, size_t *binszp); +bool base58_encode(const void *data, size_t binsz, char *b58, size_t *b58sz); + +#endif + + +