From 79df10f7829674fab7c6d265db1bdd0496b1633a Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Thu, 26 Oct 2017 13:24:19 +1030 Subject: [PATCH] bech32: pull in bech32 sample code, almost untouched. Signed-off-by: Rusty Russell --- lightningd/Makefile | 1 + lightningd/bech32.c | 195 ++++++++++++++++++++++++++++++++++++++++++++ lightningd/bech32.h | 122 +++++++++++++++++++++++++++ 3 files changed, 318 insertions(+) create mode 100644 lightningd/bech32.c create mode 100644 lightningd/bech32.h diff --git a/lightningd/Makefile b/lightningd/Makefile index 061c9233f..de0a6c50a 100644 --- a/lightningd/Makefile +++ b/lightningd/Makefile @@ -39,6 +39,7 @@ LIGHTNINGD_COMMON_OBJS := \ common/withdraw_tx.o LIGHTNINGD_SRC := \ + lightningd/bech32.c \ lightningd/bitcoind.c \ lightningd/build_utxos.c \ lightningd/chaintopology.c \ diff --git a/lightningd/bech32.c b/lightningd/bech32.c new file mode 100644 index 000000000..0c4f115bb --- /dev/null +++ b/lightningd/bech32.c @@ -0,0 +1,195 @@ +/* Stolen from https://github.com/sipa/bech32/blob/master/ref/c/segwit_addr.c, + * with only the two ' > 90' checks hoisted, and more internals exposed */ + +/* Copyright (c) 2017 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 "bech32.h" + +#include +#include +#include + +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); +} + +const char bech32_charset[32] = "qpzry9x8gf2tvdw0s3jn54khce6mua7l"; + +const int8_t bech32_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, size_t max_input_len) { + 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 > max_input_len) 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++) = bech32_charset[*(data++)]; + } + for (i = 0; i < 6; ++i) { + chk = bech32_polymod_step(chk); + } + chk ^= 1; + for (i = 0; i < 6; ++i) { + *(output++) = bech32_charset[(chk >> ((5 - i) * 5)) & 0x1f]; + } + *output = 0; + return 1; +} + +int bech32_decode(char* hrp, uint8_t *data, size_t *data_len, const char *input, + size_t max_input_len) { + uint32_t chk = 1; + size_t i; + size_t input_len = strlen(input); + size_t hrp_len; + int have_lower = 0, have_upper = 0; + if (input_len < 8 || input_len > max_input_len) { + return 0; + } + *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 (hrp_len < 1 || *data_len < 6) { + return 0; + } + *(data_len) -= 6; + for (i = 0; i < hrp_len; ++i) { + int ch = input[i]; + if (ch < 33 || ch > 126) { + return 0; + } + 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 : bech32_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 0; + } + chk = bech32_polymod_step(chk) ^ v; + if (i + 6 < input_len) { + data[i - (1 + hrp_len)] = v; + } + ++i; + } + if (have_lower && have_upper) { + return 0; + } + return chk == 1; +} + +int bech32_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]; + size_t datalen = 0; + 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; + data[0] = witver; + bech32_convert_bits(data + 1, &datalen, 5, witprog, witprog_len, 8, 1); + ++datalen; + return bech32_encode(output, hrp, data, datalen, 90); +} + +int segwit_addr_decode(int* witver, uint8_t* witdata, size_t* witdata_len, const char* hrp, const char* addr) { + uint8_t data[84]; + char hrp_actual[84]; + size_t data_len; + if (!bech32_decode(hrp_actual, data, &data_len, addr, 90)) 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; + *witdata_len = 0; + if (!bech32_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; +} diff --git a/lightningd/bech32.h b/lightningd/bech32.h new file mode 100644 index 000000000..072b31293 --- /dev/null +++ b/lightningd/bech32.h @@ -0,0 +1,122 @@ +/* Stolen from https://github.com/sipa/bech32/blob/master/ref/c/segwit_addr.h, + * with only the two ' > 90' checks hoisted */ + +/* Copyright (c) 2017 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. + */ + +#ifndef _SEGWIT_ADDR_H_ +#define _SEGWIT_ADDR_H_ 1 +#include "config.h" + +#include +#include + +/** Encode a SegWit address + * + * Out: output: Pointer to a buffer of size 73 + strlen(hrp) that will be + * updated to contain the null-terminated address. + * In: hrp: Pointer to the null-terminated human readable part to use + * (chain/network specific). + * ver: Version of the witness program (between 0 and 16 inclusive). + * prog: Data bytes for the witness program (between 2 and 40 bytes). + * prog_len: Number of data bytes in prog. + * Returns 1 if successful. + */ +int segwit_addr_encode( + char *output, + const char *hrp, + int ver, + const uint8_t *prog, + size_t prog_len +); + +/** Decode a SegWit address + * + * Out: ver: Pointer to an int that will be updated to contain the witness + * program version (between 0 and 16 inclusive). + * prog: Pointer to a buffer of size 40 that will be updated to + * contain the witness program bytes. + * prog_len: Pointer to a size_t that will be updated to contain the length + * of bytes in prog. + * hrp: Pointer to the null-terminated human readable part that is + * expected (chain/network specific). + * addr: Pointer to the null-terminated address. + * Returns 1 if successful. + */ +int segwit_addr_decode( + int* ver, + uint8_t* prog, + size_t* prog_len, + const char* hrp, + const char* addr +); + +/** Encode a Bech32 string + * + * Out: output: Pointer to a buffer of size strlen(hrp) + data_len + 8 that + * will be updated to contain the null-terminated Bech32 string. + * In: hrp : Pointer to the null-terminated human readable part. + * data : Pointer to an array of 5-bit values. + * data_len: Length of the data array. + * max_input_len: Maximum valid length of input (90 for segwit usage). + * Returns 1 if successful. + */ +int bech32_encode( + char *output, + const char *hrp, + const uint8_t *data, + size_t data_len, + size_t max_input_len +); + +/** Decode a Bech32 string + * + * Out: hrp: Pointer to a buffer of size strlen(input) - 6. Will be + * updated to contain the null-terminated human readable part. + * data: Pointer to a buffer of size strlen(input) - 8 that will + * hold the encoded 5-bit data values. + * data_len: Pointer to a size_t that will be updated to be the number + * of entries in data. + * In: input: Pointer to a null-terminated Bech32 string. + * max_input_len: Maximum valid length of input (90 for segwit usage). + * Returns 1 if succesful. + */ +int bech32_decode( + char *hrp, + uint8_t *data, + size_t *data_len, + const char *input, + size_t max_input_len +); + +/* Helper from bech32: translates inbits-bit bytes to outbits-bit bytes. + * @outlen is incremented as bytes are added. + * @pad is true if we're to pad, otherwise truncate last byte if necessary + */ +int bech32_convert_bits(uint8_t* out, size_t* outlen, int outbits, + const uint8_t* in, size_t inlen, int inbits, + int pad); + +/* The charset, and reverse mapping */ +extern const char bech32_charset[32]; +extern const int8_t bech32_charset_rev[128]; + +#endif /* LIGHTNING_LIGHTNINGD_BECH32_H */