LibRHash

Description

LibRHash is a professional, portable, thread-safe C library for computing a wide variety of hash sums.

Main features

• Small and easy to learn interface.
• Hi-level and Low-level API.
• Calculates several hash functions simultaneously in one pass.
• Extremely portable: works the same on Linux, *BSD and Windows.
• Written in pure C, small in size, open source.

License

The library is in public domain. The source code is licensed under RHash License.

Basically the library and its source code can be used for free in Commercial, Open Source and other projects.

Source code

The library is distributed as part of the RHash source tree and
can be downloaded from https://github.com/rhash/RHash/releases

Usage examples

Low-level interface

• Calculating MD4 and MD5 digests simultaneously of a million characters of 'a'

 #include "rhash.h" /* LibRHash interface */

 int main(int argc, char *argv[]) {
   rhash context;
   char digest[64];
   char output[130];
   int i;

   rhash_library_init(); /* initialize static data */

   context = rhash_init(RHASH_MD4 | RHASH_MD5);
   if(!context) {
     fprintf(stderr, "error: couldn't initialize rhash context\n");
     return 1;
   }

   for(i = 0; i < 1000000; i++) {
     rhash_update(context, "a", 1);
   }
   rhash_final(context, NULL); /* finalize hash calculation */

   /* output digest as a hexadecimal hash string */
   rhash_print(output, context, RHASH_MD4, RHPR_UPPERCASE); 
   printf("%s ('a'x1000000) = %s\n", rhash_get_name(RHASH_MD4), output);

   rhash_print(output, context, RHASH_MD5, RHPR_UPPERCASE); 
   printf("%s ('a'x1000000) = %s\n", rhash_get_name(RHASH_MD5), output);

   rhash_free(context);
   return 0;
 }

Hi-level interface

• Calculating SHA1 hash of a string

 #include <string.h>
 #include "rhash.h" /* LibRHash interface */

 int main(int argc, char *argv[])
 {
   const char* msg = "message digest";
   char digest[64];
   char output[130];

   rhash_library_init(); /* initialize static data */

   int res = rhash_msg(RHASH_SHA1, msg, strlen(msg), digest);
   if(res < 0) {
     fprintf(stderr, "hash calculation error\n");
     return 1;
   }

   /* convert binary digest to hexadecimal string */
   rhash_print_bytes(output, digest, rhash_get_digest_size(RHASH_SHA1),
       (RHPR_HEX | RHPR_UPPERCASE));

   printf("%s (\"%s\") = %s\n", rhash_get_name(RHASH_SHA1), msg, output);
   return 0;
 }

• Calculating TTH hash of a file

 #include <errno.h>
 #include "rhash.h" /* LibRHash interface */

 int main(int argc, char *argv[])
 {
   const char* filepath = "test_file.txt";
   char digest[64];
   char output[130];

   rhash_library_init(); /* initialize static data */

   int res = rhash_file(RHASH_TTH, filepath, digest);
   if(res < 0) {
     fprintf(stderr, "LibRHash error: %s: %s\n", filepath, strerror(errno));
     return 1;
   }

   /* convert binary digest to hexadecimal string */
   rhash_print_bytes(output, digest, rhash_get_digest_size(RHASH_TTH),
       (RHPR_BASE32 | RHPR_UPPERCASE));

   printf("%s (%s) = %s\n", rhash_get_name(RHASH_TTH), filepath, output);
   return 0;
 }