1 /* Stolen from https://github.com/sipa/bech32/blob/master/ref/c/segwit_addr.h, 2 * with only the two ' > 90' checks hoisted */ 3 4 /* Copyright (c) 2017, 2021 Pieter Wuille 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a copy 7 * of this software and associated documentation files (the "Software"), to deal 8 * in the Software without restriction, including without limitation the rights 9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 10 * copies of the Software, and to permit persons to whom the Software is 11 * furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be included in 14 * all copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 19 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 22 * THE SOFTWARE. 23 */ 24 25 #ifndef LIGHTNING_COMMON_BECH32_H 26 #define LIGHTNING_COMMON_BECH32_H 27 #include "config.h" 28 29 #include <stdint.h> 30 #include <stdlib.h> 31 32 /** Encode a SegWit address 33 * 34 * Out: output: Pointer to a buffer of size 73 + strlen(hrp) that will be 35 * updated to contain the null-terminated address. 36 * In: hrp: Pointer to the null-terminated human readable part to use 37 * (chain/network specific). 38 * ver: Version of the witness program (between 0 and 16 inclusive). 39 * prog: Data bytes for the witness program (between 2 and 40 bytes). 40 * prog_len: Number of data bytes in prog. 41 * Returns 1 if successful. 42 */ 43 int segwit_addr_encode( 44 char *output, 45 const char *hrp, 46 int ver, 47 const uint8_t *prog, 48 size_t prog_len 49 ); 50 51 /** Decode a SegWit address 52 * 53 * Out: ver: Pointer to an int that will be updated to contain the witness 54 * program version (between 0 and 16 inclusive). 55 * prog: Pointer to a buffer of size 40 that will be updated to 56 * contain the witness program bytes. 57 * prog_len: Pointer to a size_t that will be updated to contain the length 58 * of bytes in prog. 59 * hrp: Pointer to the null-terminated human readable part that is 60 * expected (chain/network specific). 61 * addr: Pointer to the null-terminated address. 62 * Returns 1 if successful. 63 */ 64 int segwit_addr_decode( 65 int* ver, 66 uint8_t* prog, 67 size_t* prog_len, 68 const char* hrp, 69 const char* addr 70 ); 71 72 /** Supported encodings. */ 73 typedef enum { 74 BECH32_ENCODING_NONE, 75 BECH32_ENCODING_BECH32, 76 BECH32_ENCODING_BECH32M 77 } bech32_encoding; 78 79 /** Encode a Bech32 or Bech32m string 80 * 81 * Out: output: Pointer to a buffer of size strlen(hrp) + data_len + 8 that 82 * will be updated to contain the null-terminated Bech32 string. 83 * In: hrp : Pointer to the null-terminated human readable part. 84 * data : Pointer to an array of 5-bit values. 85 * data_len: Length of the data array. 86 * max_input_len: Maximum valid length of input (90 for segwit usage). 87 * enc: Which encoding to use (BECH32_ENCODING_BECH32{,M}). 88 * Returns 1 if successful. 89 */ 90 int bech32_encode( 91 char *output, 92 const char *hrp, 93 const uint8_t *data, 94 size_t data_len, 95 size_t max_input_len, 96 bech32_encoding enc 97 ); 98 99 /** Decode a Bech32 or Bech32m string 100 * 101 * Out: hrp: Pointer to a buffer of size strlen(input) - 6. Will be 102 * updated to contain the null-terminated human readable part. 103 * data: Pointer to a buffer of size strlen(input) - 8 that will 104 * hold the encoded 5-bit data values. 105 * data_len: Pointer to a size_t that will be updated to be the number 106 * of entries in data. 107 * In: input: Pointer to a null-terminated Bech32 string. 108 * max_input_len: Maximum valid length of input (90 for segwit usage). 109 * Returns BECH32_ENCODING_BECH32{,M} to indicate decoding was successful 110 * with the specified encoding standard. BECH32_ENCODING_NONE is returned if 111 * decoding failed. 112 */ 113 bech32_encoding bech32_decode( 114 char *hrp, 115 uint8_t *data, 116 size_t *data_len, 117 const char *input, 118 size_t max_input_len 119 ); 120 121 /* Helper from bech32: translates inbits-bit bytes to outbits-bit bytes. 122 * @outlen is incremented as bytes are added. 123 * @pad is true if we're to pad, otherwise truncate last byte if necessary 124 */ 125 int bech32_convert_bits(uint8_t* out, size_t* outlen, int outbits, 126 const uint8_t* in, size_t inlen, int inbits, 127 int pad); 128 129 /* The charset, and reverse mapping */ 130 extern const char bech32_charset[32]; 131 extern const int8_t bech32_charset_rev[128]; 132 133 #endif /* LIGHTNING_COMMON_BECH32_H */ 134 135