| /* mcookie.c -- Generates random numbers for xauth |
| * Created: Fri Feb 3 10:42:48 1995 by faith@cs.unc.edu |
| * Revised: Fri Mar 19 07:48:01 1999 by faith@acm.org |
| * Public Domain 1995, 1999 Rickard E. Faith (faith@acm.org) |
| * This program comes with ABSOLUTELY NO WARRANTY. |
| * |
| * $Id: mcookie.c,v 1.5 1997/07/06 00:13:06 aebr Exp $ |
| * |
| * This program gathers some random bits of data and used the MD5 |
| * message-digest algorithm to generate a 128-bit hexadecimal number for |
| * use with xauth(1). |
| * |
| * NOTE: Unless /dev/random is available, this program does not actually |
| * gather 128 bits of random information, so the magic cookie generated |
| * will be considerably easier to guess than one might expect. |
| * |
| * 1999-02-22 Arkadiusz Mi¶kiewicz <misiek@pld.ORG.PL> |
| * - added Native Language Support |
| * 1999-03-21 aeb: Added some fragments of code from Colin Plumb. |
| * |
| */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <fcntl.h> |
| #include <sys/time.h> |
| #include <time.h> |
| #include <unistd.h> |
| |
| #define BUFFERSIZE 4096 |
| |
| |
| #ifndef MD5_H |
| #define MD5_H |
| |
| #if defined (__alpha__) || defined (__ia64__) || defined (__x86_64__) |
| typedef unsigned int uint32; |
| #else |
| typedef unsigned long uint32; |
| #endif |
| |
| struct MD5Context { |
| uint32 buf[4]; |
| uint32 bits[2]; |
| unsigned char in[64]; |
| }; |
| |
| void MD5Init(struct MD5Context *context); |
| void MD5Update(struct MD5Context *context, unsigned char const *buf, |
| unsigned len); |
| void MD5Final(unsigned char digest[16], struct MD5Context *context); |
| void MD5Transform(uint32 buf[4], uint32 const in[16]); |
| |
| /* |
| * This is needed to make RSAREF happy on some MS-DOS compilers. |
| */ |
| typedef struct MD5Context MD5_CTX; |
| |
| #endif /* !MD5_H */ |
| |
| |
| |
| /* |
| * This code implements the MD5 message-digest algorithm. |
| * The algorithm is due to Ron Rivest. This code was |
| * written by Colin Plumb in 1993, no copyright is claimed. |
| * This code is in the public domain; do with it what you wish. |
| * |
| * Equivalent code is available from RSA Data Security, Inc. |
| * This code has been tested against that, and is equivalent, |
| * except that you don't need to include two pages of legalese |
| * with every copy. |
| * |
| * To compute the message digest of a chunk of bytes, declare an |
| * MD5Context structure, pass it to MD5Init, call MD5Update as |
| * needed on buffers full of bytes, and then call MD5Final, which |
| * will fill a supplied 16-byte array with the digest. |
| */ |
| #include <string.h> /* for memcpy() */ |
| #include <endian.h> |
| |
| #if __BYTE_ORDER == __LITTLE_ENDIAN |
| #define byteReverse(buf, len) /* Nothing */ |
| #else |
| void byteReverse(unsigned char *buf, unsigned longs); |
| |
| /* |
| * Note: this code is harmless on little-endian machines. |
| */ |
| void byteReverse(unsigned char *buf, unsigned longs) |
| { |
| uint32 t; |
| do { |
| t = (uint32) ((unsigned) buf[3] << 8 | buf[2]) << 16 | |
| ((unsigned) buf[1] << 8 | buf[0]); |
| *(uint32 *) buf = t; |
| buf += 4; |
| } while (--longs); |
| } |
| #endif |
| |
| /* |
| * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious |
| * initialization constants. |
| */ |
| void MD5Init(struct MD5Context *ctx) |
| { |
| ctx->buf[0] = 0x67452301; |
| ctx->buf[1] = 0xefcdab89; |
| ctx->buf[2] = 0x98badcfe; |
| ctx->buf[3] = 0x10325476; |
| |
| ctx->bits[0] = 0; |
| ctx->bits[1] = 0; |
| } |
| |
| /* |
| * Update context to reflect the concatenation of another buffer full |
| * of bytes. |
| */ |
| void MD5Update(struct MD5Context *ctx, unsigned char const *buf, unsigned len) |
| { |
| uint32 t; |
| |
| /* Update bitcount */ |
| |
| t = ctx->bits[0]; |
| if ((ctx->bits[0] = t + ((uint32) len << 3)) < t) |
| ctx->bits[1]++; /* Carry from low to high */ |
| ctx->bits[1] += len >> 29; |
| |
| t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */ |
| |
| /* Handle any leading odd-sized chunks */ |
| |
| if (t) { |
| unsigned char *p = (unsigned char *) ctx->in + t; |
| |
| t = 64 - t; |
| if (len < t) { |
| memcpy(p, buf, len); |
| return; |
| } |
| memcpy(p, buf, t); |
| byteReverse(ctx->in, 16); |
| MD5Transform(ctx->buf, (uint32 *) ctx->in); |
| buf += t; |
| len -= t; |
| } |
| /* Process data in 64-byte chunks */ |
| |
| while (len >= 64) { |
| memcpy(ctx->in, buf, 64); |
| byteReverse(ctx->in, 16); |
| MD5Transform(ctx->buf, (uint32 *) ctx->in); |
| buf += 64; |
| len -= 64; |
| } |
| |
| /* Handle any remaining bytes of data. */ |
| |
| memcpy(ctx->in, buf, len); |
| } |
| |
| /* |
| * Final wrapup - pad to 64-byte boundary with the bit pattern |
| * 1 0* (64-bit count of bits processed, MSB-first) |
| */ |
| void MD5Final(unsigned char digest[16], struct MD5Context *ctx) |
| { |
| unsigned count; |
| unsigned char *p; |
| |
| /* Compute number of bytes mod 64 */ |
| count = (ctx->bits[0] >> 3) & 0x3F; |
| |
| /* Set the first char of padding to 0x80. This is safe since there is |
| always at least one byte free */ |
| p = ctx->in + count; |
| *p++ = 0x80; |
| |
| /* Bytes of padding needed to make 64 bytes */ |
| count = 64 - 1 - count; |
| |
| /* Pad out to 56 mod 64 */ |
| if (count < 8) { |
| /* Two lots of padding: Pad the first block to 64 bytes */ |
| memset(p, 0, count); |
| byteReverse(ctx->in, 16); |
| MD5Transform(ctx->buf, (uint32 *) ctx->in); |
| |
| /* Now fill the next block with 56 bytes */ |
| memset(ctx->in, 0, 56); |
| } else { |
| /* Pad block to 56 bytes */ |
| memset(p, 0, count - 8); |
| } |
| byteReverse(ctx->in, 14); |
| |
| /* Append length in bits and transform */ |
| ((uint32 *) ctx->in)[14] = ctx->bits[0]; |
| ((uint32 *) ctx->in)[15] = ctx->bits[1]; |
| |
| MD5Transform(ctx->buf, (uint32 *) ctx->in); |
| byteReverse((unsigned char *) ctx->buf, 4); |
| memcpy(digest, ctx->buf, 16); |
| memset(ctx, 0, sizeof(*ctx)); /* In case it's sensitive */ |
| } |
| |
| /* The four core functions - F1 is optimized somewhat */ |
| |
| /* #define F1(x, y, z) (x & y | ~x & z) */ |
| #define F1(x, y, z) (z ^ (x & (y ^ z))) |
| #define F2(x, y, z) F1(z, x, y) |
| #define F3(x, y, z) (x ^ y ^ z) |
| #define F4(x, y, z) (y ^ (x | ~z)) |
| |
| /* This is the central step in the MD5 algorithm. */ |
| #define MD5STEP(f, w, x, y, z, data, s) \ |
| ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x ) |
| |
| /* |
| * The core of the MD5 algorithm, this alters an existing MD5 hash to |
| * reflect the addition of 16 longwords of new data. MD5Update blocks |
| * the data and converts bytes into longwords for this routine. |
| */ |
| void MD5Transform(uint32 buf[4], uint32 const in[16]) |
| { |
| register uint32 a, b, c, d; |
| |
| a = buf[0]; |
| b = buf[1]; |
| c = buf[2]; |
| d = buf[3]; |
| |
| MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7); |
| MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12); |
| MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17); |
| MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22); |
| MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7); |
| MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12); |
| MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17); |
| MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22); |
| MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7); |
| MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12); |
| MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17); |
| MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22); |
| MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7); |
| MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12); |
| MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17); |
| MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22); |
| |
| MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5); |
| MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9); |
| MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14); |
| MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20); |
| MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5); |
| MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9); |
| MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14); |
| MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20); |
| MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5); |
| MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9); |
| MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14); |
| MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20); |
| MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5); |
| MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9); |
| MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14); |
| MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20); |
| |
| MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4); |
| MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11); |
| MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16); |
| MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23); |
| MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4); |
| MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11); |
| MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16); |
| MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23); |
| MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4); |
| MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11); |
| MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16); |
| MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23); |
| MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4); |
| MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11); |
| MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16); |
| MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23); |
| |
| MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6); |
| MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10); |
| MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15); |
| MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21); |
| MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6); |
| MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10); |
| MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15); |
| MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21); |
| MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6); |
| MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10); |
| MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15); |
| MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21); |
| MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6); |
| MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10); |
| MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15); |
| MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21); |
| |
| buf[0] += a; |
| buf[1] += b; |
| buf[2] += c; |
| buf[3] += d; |
| } |
| |
| |
| |
| |
| struct rngs { |
| const char *path; |
| int minlength, maxlength; |
| } rngs[] = { |
| { "/dev/random", 16, 16 }, /* 16 bytes = 128 bits suffice */ |
| { "/proc/interrupts", 0, 0 }, |
| { "/proc/slabinfo", 0, 0 }, |
| { "/proc/stat", 0, 0 }, |
| { "/dev/urandom", 32, 64 }, |
| }; |
| #define RNGS (sizeof(rngs)/sizeof(struct rngs)) |
| |
| int Verbose = 0; |
| |
| /* The basic function to hash a file */ |
| static off_t |
| hash_file(struct MD5Context *ctx, int fd) |
| { |
| off_t count = 0; |
| ssize_t r; |
| unsigned char buf[BUFFERSIZE]; |
| |
| while ((r = read(fd, buf, sizeof(buf))) > 0) { |
| MD5Update(ctx, buf, r); |
| count += r; |
| } |
| /* Separate files with a null byte */ |
| buf[0] = 0; |
| MD5Update(ctx, buf, 1); |
| return count; |
| } |
| |
| int main( int argc, char **argv ) |
| { |
| int i; |
| struct MD5Context ctx; |
| unsigned char digest[16]; |
| unsigned char buf[BUFFERSIZE]; |
| int fd; |
| int c; |
| pid_t pid; |
| char *file = NULL; |
| int r; |
| struct timeval tv; |
| struct timezone tz; |
| |
| while ((c = getopt( argc, argv, "vf:" )) != -1) |
| switch (c) { |
| case 'v': ++Verbose; break; |
| case 'f': file = optarg; break; |
| } |
| |
| MD5Init( &ctx ); |
| |
| gettimeofday( &tv, &tz ); |
| MD5Update( &ctx, (unsigned char *)&tv, sizeof( tv ) ); |
| pid = getppid(); |
| MD5Update( &ctx, (unsigned char *)&pid, sizeof( pid )); |
| pid = getpid(); |
| MD5Update( &ctx, (unsigned char *)&pid, sizeof( pid )); |
| |
| if (file) { |
| int count = 0; |
| |
| if (file[0] == '-' && !file[1]) |
| fd = fileno(stdin); |
| else |
| fd = open( file, O_RDONLY ); |
| |
| if (fd < 0) { |
| fprintf( stderr, "Could not open %s\n", file ); |
| } else { |
| count = hash_file( &ctx, fd ); |
| if (Verbose) |
| fprintf( stderr, "Got %d bytes from %s\n", count, file ); |
| |
| if (file[0] != '-' || file[1]) close( fd ); |
| } |
| } |
| |
| for (i = 0; i < RNGS; i++) { |
| if ((fd = open( rngs[i].path, O_RDONLY|O_NONBLOCK )) >= 0) { |
| int count = sizeof(buf); |
| |
| if (rngs[i].maxlength && count > rngs[i].maxlength) |
| count = rngs[i].maxlength; |
| r = read( fd, buf, count ); |
| if (r > 0) |
| MD5Update( &ctx, buf, r ); |
| else |
| r = 0; |
| close( fd ); |
| if (Verbose) |
| fprintf( stderr, "Got %d bytes from %s\n", r, rngs[i].path ); |
| if (rngs[i].minlength && r >= rngs[i].minlength) |
| break; |
| } else if (Verbose) |
| fprintf( stderr, "Could not open %s\n", rngs[i].path ); |
| } |
| |
| MD5Final( digest, &ctx ); |
| for (i = 0; i < 16; i++) printf( "%02x", digest[i] ); |
| putchar ( '\n' ); |
| |
| /* |
| * The following is important for cases like disk full, so shell scripts |
| * can bomb out properly rather than think they succeeded. |
| */ |
| if (fflush(stdout) < 0 || fclose(stdout) < 0) |
| return 1; |
| |
| return 0; |
| } |