smatch_hash.c

   1 /*
   2  * Copyright (C) 2022 Oracle.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version 2
   7  * of the License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, see http://www.gnu.org/copyleft/gpl.txt
  16  */
  17
  18 #include <string.h>
  19 #include <openssl/evp.h>
  20
  21 #define MTAG_ALIAS_BIT (1ULL << 63)
  22
  23 unsigned long long str_to_llu_hash_helper(const char *str)
  24 {
  25         unsigned char c[EVP_MAX_MD_SIZE];
  26         unsigned long long *tag = (unsigned long long *)&c;
  27         EVP_MD_CTX *mdctx;
  28         const EVP_MD *md;
  29         int len;
  30
  31         len = strlen(str);
  32
  33         mdctx = EVP_MD_CTX_create();
  34         md = EVP_sha1();
  35
  36         EVP_DigestInit_ex(mdctx, md, NULL);
  37         EVP_DigestUpdate(mdctx, str, len);
  38         EVP_DigestFinal_ex(mdctx, c, NULL);
  39         EVP_MD_CTX_destroy(mdctx);
  40
  41         /* I don't like negatives in the DB */
  42         *tag &= ~MTAG_ALIAS_BIT;
  43
  44         return *tag;
  45 }
  46