imap/src/c-client/sha.c

   1 /*
   2  * Copyright 2021-2022 Eduardo Chappa
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  */
  11 /* This algorithm is taken from the code in RFC 4634 */
  12
  13 #include "c-client.h"
  14 #include "sha.h"
  15 #include "hmac.c"
  16 #include "sha1.c"
  17 #include "usha.c"
  18 #include "sha224-256.c"
  19 #include "sha384-512.c"
  20
  21 struct hash {
  22     char *name;
  23     SHAversion whichSha;
  24     int hashsize;
  25 } hashes[] = {
  26   {"SHA1", CCSHA1, SHA1HashSize},
  27   {"SHA224", CCSHA224, SHA224HashSize},
  28   {"SHA256", CCSHA256, SHA256HashSize},
  29   {"SHA384", CCSHA384, SHA384HashSize},
  30   {"SHA512", CCSHA512, SHA512HashSize},
  31   {NIL, CCSHA512, SHA512HashSize}
  32 };
  33 static const char hexdigits[] = "0123456789abcdef";
  34
  35 char *hash_from_sizedtext(char *hash, char *text, size_t len, unsigned char **digest)
  36 {
  37   char *rv = NIL;
  38   USHAContext sha;
  39   HMACContext hmac;
  40   uint8_t Message_Digest[USHAMaxHashSize];
  41   int i, hashno;
  42   unsigned long len2;
  43
  44   if(digest) *digest = NIL;
  45
  46   if(!hash || !text) return NIL;
  47
  48   for(hashno = 0; hashes[hashno].name != NIL; hashno++)
  49      if(!compare_cstring(hashes[hashno].name, hash))
  50         break;
  51
  52   if(hashno >= 0 && hashno <= USHAMaxHashSize && hashes[hashno].name){
  53      memset(&sha, '\343', sizeof(USHAContext));
  54      memset(&hmac, '\343', sizeof(HMACContext));
  55      if(USHAReset(&sha, hashes[hashno].whichSha) == shaSuccess
  56         && USHAInput(&sha, (const uint8_t *) text, len) == shaSuccess){
  57         if(USHAResult(&sha, (uint8_t *) Message_Digest) == shaSuccess){
  58            if(digest) *digest = rfc822_urlbinary((void *) Message_Digest, hashes[hashno].hashsize, &len2);
  59            rv = fs_get(2*hashes[hashno].hashsize + 1);
  60            for (i = 0; i < hashes[hashno].hashsize ; ++i) {
  61               rv[2*i]   = hexdigits[(Message_Digest[i] >> 4) & 0xF];
  62               rv[2*i+1] = hexdigits[Message_Digest[i] & 0xF];
  63            }
  64            rv[2*i] = '\0';
  65         }
  66      }
  67   }
  68   return rv;
  69 }