lnsocket

A minimal C library for connecting to the lightning network
git clone git://jb55.com/lnsocket
Log | Files | Refs | Submodules | README | LICENSE

bech32.h (5052B)


      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