| int unhexify(unsigned char *obuf, const char *ibuf) |
| { |
| unsigned char c, c2; |
| int len = strlen(ibuf) / 2; |
| assert(!(strlen(ibuf) %1)); // must be even number of bytes |
| |
| while (*ibuf != 0) |
| { |
| c = *ibuf++; |
| if( c >= '0' && c <= '9' ) |
| c -= '0'; |
| else if( c >= 'a' && c <= 'f' ) |
| c -= 'a' - 10; |
| else if( c >= 'A' && c <= 'F' ) |
| c -= 'A' - 10; |
| else |
| assert( 0 ); |
| |
| c2 = *ibuf++; |
| if( c2 >= '0' && c2 <= '9' ) |
| c2 -= '0'; |
| else if( c2 >= 'a' && c2 <= 'f' ) |
| c2 -= 'a' - 10; |
| else if( c2 >= 'A' && c2 <= 'F' ) |
| c2 -= 'A' - 10; |
| else |
| assert( 0 ); |
| |
| *obuf++ = ( c << 4 ) | c2; |
| } |
| |
| return len; |
| } |
| |
| void hexify(unsigned char *obuf, const unsigned char *ibuf, int len) |
| { |
| unsigned char l, h; |
| |
| while (len != 0) |
| { |
| h = (*ibuf) / 16; |
| l = (*ibuf) % 16; |
| |
| if( h < 10 ) |
| *obuf++ = '0' + h; |
| else |
| *obuf++ = 'a' + h - 10; |
| |
| if( l < 10 ) |
| *obuf++ = '0' + l; |
| else |
| *obuf++ = 'a' + l - 10; |
| |
| ++ibuf; |
| len--; |
| } |
| } |
| |
| /** |
| * This function just returns data from rand(). |
| * |
| * rng_state shall be NULL. |
| */ |
| static int rnd_std_rand( void *rng_state ) |
| { |
| if( rng_state != NULL ) |
| rng_state = NULL; |
| |
| return( rand() ); |
| } |
| |
| /** |
| * This function only returns zeros |
| * |
| * rng_state shall be NULL. |
| */ |
| static int rnd_zero_rand( void *rng_state ) |
| { |
| if( rng_state != NULL ) |
| rng_state = NULL; |
| |
| return( 0 ); |
| } |
| |
| typedef struct |
| { |
| unsigned char *buf; |
| int length; |
| int per_call; |
| } rnd_info; |
| |
| /** |
| * This function returns random based on a buffer it receives. |
| * |
| * rng_state shall be a pointer to a rnd_buf structure. |
| * |
| * After the buffer is empty it will return rand(); |
| */ |
| static int rnd_buffer_rand( void *rng_state ) |
| { |
| rnd_info *info = (rnd_info *) rng_state; |
| int res; |
| |
| if( rng_state == NULL ) |
| return( rand() ); |
| |
| res = rand(); |
| |
| if( info->length >= info->per_call ) |
| { |
| memcpy( &res, info->buf, info->per_call ); |
| info->buf += info->per_call; |
| info->length -= info->per_call; |
| } |
| else if( info->length > 0 ) |
| { |
| memcpy( &res, info->buf, info->length ); |
| info->length = 0; |
| } |
| |
| return( res ); |
| } |