/* Copyright (c) 2017, 2021 Pieter Wuille * * 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 <stdlib.h> #include <stdint.h> #include <string.h> #include "segwit_addr.h" static uint32_t bech32_polymod_step(uint32_t pre) { uint8_t b = pre >> 25; return ((pre & 0x1FFFFFF) << 5) ^ (-((b >> 0) & 1) & 0x3b6a57b2UL) ^ (-((b >> 1) & 1) & 0x26508e6dUL) ^ (-((b >> 2) & 1) & 0x1ea119faUL) ^ (-((b >> 3) & 1) & 0x3d4233ddUL) ^ (-((b >> 4) & 1) & 0x2a1462b3UL); } static uint32_t bech32_final_constant(bech32_encoding enc) { if (enc == BECH32_ENCODING_BECH32) return 1; if (enc == BECH32_ENCODING_BECH32M) return 0x2bc830a3; return 0; } static const char* charset = "qpzry9x8gf2tvdw0s3jn54khce6mua7l"; static const int8_t charset_rev[128] = { -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, 15, -1, 10, 17, 21, 20, 26, 30, 7, 5, -1, -1, -1, -1, -1, -1, -1, 29, -1, 24, 13, 25, 9, 8, 23, -1, 18, 22, 31, 27, 19, -1, 1, 0, 3, 16, 11, 28, 12, 14, 6, 4, 2, -1, -1, -1, -1, -1, -1, 29, -1, 24, 13, 25, 9, 8, 23, -1, 18, 22, 31, 27, 19, -1, 1, 0, 3, 16, 11, 28, 12, 14, 6, 4, 2, -1, -1, -1, -1, -1 }; int bech32_encode(char *output, const char *hrp, const uint8_t *data, size_t data_len, bech32_encoding enc) { uint32_t chk = 1; size_t i = 0; while (hrp[i] != 0) { int ch = hrp[i]; if (ch < 33 || ch > 126) { return 0; } if (ch >= 'A' && ch <= 'Z') return 0; chk = bech32_polymod_step(chk) ^ (ch >> 5); ++i; } if (i + 7 + data_len > 90) return 0; chk = bech32_polymod_step(chk); while (*hrp != 0) { chk = bech32_polymod_step(chk) ^ (*hrp & 0x1f); *(output++) = *(hrp++); } *(output++) = '1'; for (i = 0; i < data_len; ++i) { if (*data >> 5) return 0; chk = bech32_polymod_step(chk) ^ (*data); *(output++) = charset[*(data++)]; } for (i = 0; i < 6; ++i) { chk = bech32_polymod_step(chk); } chk ^= bech32_final_constant(enc); for (i = 0; i < 6; ++i) { *(output++) = charset[(chk >> ((5 - i) * 5)) & 0x1f]; } *output = 0; return 1; } bech32_encoding bech32_decode(char* hrp, uint8_t *data, size_t *data_len, const char *input) { uint32_t chk = 1; size_t i = 0; size_t input_len = strlen(input); size_t hrp_len = 0; int have_lower = 0, have_upper = 0; if (input_len < 8 || input_len > 90) { return BECH32_ENCODING_NONE; } *data_len = 0; while (*data_len < input_len && input[(input_len - 1) - *data_len] != '1') { ++(*data_len); } hrp_len = input_len - (1 + *data_len); if (1 + *data_len >= input_len || *data_len < 6) { return BECH32_ENCODING_NONE; } *(data_len) -= 6; for (i = 0; i < hrp_len; ++i) { int ch = input[i]; if (ch < 33 || ch > 126) { return BECH32_ENCODING_NONE; } if (ch >= 'a' && ch <= 'z') { have_lower = 1; } else if (ch >= 'A' && ch <= 'Z') { have_upper = 1; ch = (ch - 'A') + 'a'; } hrp[i] = ch; chk = bech32_polymod_step(chk) ^ (ch >> 5); } hrp[i] = 0; chk = bech32_polymod_step(chk); for (i = 0; i < hrp_len; ++i) { chk = bech32_polymod_step(chk) ^ (input[i] & 0x1f); } ++i; while (i < input_len) { int v = (input[i] & 0x80) ? -1 : charset_rev[(int)input[i]]; if (input[i] >= 'a' && input[i] <= 'z') have_lower = 1; if (input[i] >= 'A' && input[i] <= 'Z') have_upper = 1; if (v == -1) { return BECH32_ENCODING_NONE; } chk = bech32_polymod_step(chk) ^ v; if (i + 6 < input_len) { data[i - (1 + hrp_len)] = v; } ++i; } if (have_lower && have_upper) { return BECH32_ENCODING_NONE; } if (chk == bech32_final_constant(BECH32_ENCODING_BECH32)) { return BECH32_ENCODING_BECH32; } else if (chk == bech32_final_constant(BECH32_ENCODING_BECH32M)) { return BECH32_ENCODING_BECH32M; } else { return BECH32_ENCODING_NONE; } } static int convert_bits(uint8_t* out, size_t* outlen, int outbits, const uint8_t* in, size_t inlen, int inbits, int pad) { uint32_t val = 0; int bits = 0; uint32_t maxv = (((uint32_t)1) << outbits) - 1; while (inlen--) { val = (val << inbits) | *(in++); bits += inbits; while (bits >= outbits) { bits -= outbits; out[(*outlen)++] = (val >> bits) & maxv; } } if (pad) { if (bits) { out[(*outlen)++] = (val << (outbits - bits)) & maxv; } } else if (((val << (outbits - bits)) & maxv) || bits >= inbits) { return 0; } return 1; } int segwit_addr_encode(char *output, const char *hrp, int witver, const uint8_t *witprog, size_t witprog_len) { uint8_t data[65] = {0}; size_t datalen = 0; bech32_encoding enc = BECH32_ENCODING_BECH32; if (witver > 16) return 0; if (witver == 0 && witprog_len != 20 && witprog_len != 32) return 0; if (witprog_len < 2 || witprog_len > 40) return 0; if (witver > 0) enc = BECH32_ENCODING_BECH32M; data[0] = witver; convert_bits(data + 1, &datalen, 5, witprog, witprog_len, 8, 1); ++datalen; return bech32_encode(output, hrp, data, datalen, enc); } int segwit_addr_decode(int* witver, uint8_t* witdata, size_t* witdata_len, const char* hrp, const char* addr) { uint8_t data[84] = {0}; char hrp_actual[84] = {0}; size_t data_len = 0; bech32_encoding enc = bech32_decode(hrp_actual, data, &data_len, addr); if (enc == BECH32_ENCODING_NONE) return 0; if (data_len == 0 || data_len > 65) return 0; if (strncmp(hrp, hrp_actual, 84) != 0) return 0; if (data[0] > 16) return 0; if (data[0] == 0 && enc != BECH32_ENCODING_BECH32) return 0; if (data[0] > 0 && enc != BECH32_ENCODING_BECH32M) return 0; *witdata_len = 0; if (!convert_bits(witdata, witdata_len, 8, data + 1, data_len - 1, 5, 0)) return 0; if (*witdata_len < 2 || *witdata_len > 40) return 0; if (data[0] == 0 && *witdata_len != 20 && *witdata_len != 32) return 0; *witver = data[0]; return 1; }