damus

nostr ios client
git clone git://jb55.com/damus
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hash_u5.c (1079B)

      1 #include "config.h"
      2 #include "endian.h"
      3 #include "hash_u5.h"
      4 #include <string.h>
      5 
      6 void hash_u5_init(struct hash_u5 *hu5, const char *hrp)
      7 {
      8     hu5->buf = 0;
      9     hu5->num_bits = 0;
     10     sha256_init(&hu5->hash);
     11     sha256_update(&hu5->hash, hrp, strlen(hrp));
     12 }
     13 
     14 void hash_u5(struct hash_u5 *hu5, const u8 *u5, size_t len)
     15 {
     16     size_t bits = len * 5;
     17 
     18     while (bits) {
     19         size_t n = 5;
     20 
     21         if (bits < n)
     22             n = bits;
     23 
     24         hu5->buf <<= n;
     25         hu5->buf |= (*u5 >> (5-n));
     26         bits -= n;
     27         hu5->num_bits += n;
     28 
     29         if (n == 5)
     30             u5++;
     31 
     32         if (hu5->num_bits >= 32) {
     33             be32 be32 = cpu_to_be32((u32)(hu5->buf >> (hu5->num_bits-32)));
     34             sha256_update(&hu5->hash, &be32, sizeof(be32));
     35             hu5->num_bits -= 32;
     36         }
     37     }
     38 }
     39 
     40 void hash_u5_done(struct hash_u5 *hu5, struct sha256 *res)
     41 {
     42     if (hu5->num_bits) {
     43         be32 be32 = cpu_to_be32((u32)(hu5->buf << (32 - hu5->num_bits)));
     44 
     45         sha256_update(&hu5->hash, &be32, (hu5->num_bits + 7) / 8);
     46     }
     47     sha256_done(&hu5->hash, res);
     48 }