diff options
| -rw-r--r-- | main.c | 26 |
1 files changed, 20 insertions, 6 deletions
@@ -11,7 +11,20 @@ /* because DES discards all LSBs of every byte, * the hex alphabet can be reduced by masking out LSB from all characters */ -const char *hexchars = "02468@BDF"; +const char *keychars = "02468@BDF"; +const char *hexchars = "0123456789ABCDEF"; + +/* + * BIN2HEX: convert one byte from a byte array to a hex array + * NOTE: this routine assumes little-endian 16-bit integer + * bin: pointer to binary data + * hex: pointer to output buffer + * i: which byte to write to hex +*/ +#define BIN2HEX(bin, hex, i) \ + (((uint16_t*)(hex))[i] = \ + (hexchars[(((const char*)(bin))[i] >> 4u) & 0x0Fu]) | \ + (hexchars[(((const char*)(bin))[i]) & 0x0Fu] << 8u)) int pkcs7_check_pad(const char *buf, size_t n); @@ -54,7 +67,7 @@ bool yield_possible_key( // const char[] hexchars = {0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, // 0x38, 0x39, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46}; #define FILL_KEY(buf, key, i) \ - do { ((buf)[7-(i)] = hexchars[(key)%9u]); (key) /= 9u; } while(0) + do { ((buf)[7-(i)] = keychars[(key)%9u]); (key) /= 9u; } while(0) // buf: char[8], key: uint64_t (high bits unused), i:uint = 0, 1, 2, ..., 7 uint32_t k = ctx->next_possible_key; uint64_t plaintext; @@ -214,10 +227,11 @@ int thread_worker(thread_param *param) { /* compare md5_out[0~3] with 8-byte ASCII hex string ctx.yield */ /* hex of first 4-byte of md5_out, * 1 more byte to hold the '\0' terminator */ - char md5_hex[8 + 1]; - snprintf(md5_hex, 8 + 1, "%02X%02X%02X%02X", - md5_out[0] & 0xFFu, md5_out[1] & 0xFFu, - md5_out[2] & 0xFFu, md5_out[3] & 0xFFu); + char md5_hex[8]; + BIN2HEX(md5_out, md5_hex, 0); + BIN2HEX(md5_out, md5_hex, 1); + BIN2HEX(md5_out, md5_hex, 2); + BIN2HEX(md5_out, md5_hex, 3); /* since we have discarded the LSBs of every byte of the key, * we always yield keys whose bytes all have their LSB equals to 0. * So we mask out the LSBs from md5_hex before comparing */ |