* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- *
- * $Id$
*/
-#include "random.h"
+/** @file
+ * @brief 32-bit pseudo-random number generator implementation.
+ * @version $Id$
+ */
#include "config.h"
-#include <stdlib.h>
-#include <stdio.h>
-#include <sys/time.h>
+
+#include "random.h"
+#include "client.h"
+#include "ircd_log.h"
+#include "ircd_md5.h"
+#include "ircd_reply.h"
+#include "send.h"
#include <string.h>
+#include <sys/time.h>
-char localkey[9] = RANDOM_SEED;
+/** Pseudo-random number generator state. */
+static struct MD5Context localkey;
+/** Next byte position in #localkey to insert at. */
+static unsigned int localkey_pos;
-/*
- * MD5 transform algorithm, taken from code written by Colin Plumb,
- * and put into the public domain
- *
- * Kev: Taken from Ted T'so's /dev/random random.c code and modified to
- * be slightly simpler. That code is released under a BSD-style copyright
- * OR under the terms of the GNU Public License, which should be included
- * at the top of this source file.
- *
- * record: Cleaned up to work with ircd. RANDOM_TOKEN is defined in
- * setup.h by the make script; if people start to "guess" your cookies,
- * consider recompiling your server with a different random token.
+/** Add bytes to #localkey.
+ * This should be fairly resistant to adding non-random bytes, but the
+ * more random the bytes are, the harder it is for an attacker to
+ * guess the internal state.
+ * @param[in] buf Buffer of bytes to add.
+ * @param[in] count Number of bytes to add.
*/
+static void
+random_add_entropy(const char *buf, unsigned int count)
+{
+ while (count--) {
+ localkey.in[localkey_pos++] ^= *buf++;
+ if (localkey_pos >= sizeof(localkey.in))
+ localkey_pos = 0;
+ }
+}
-/* The four core functions - F1 is optimized somewhat */
-
-#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))
+/** Seed the PRNG with a string.
+ * @param[in] from Client setting the seed (may be NULL).
+ * @param[in] fields Input arguments (fields[0] is used).
+ * @param[in] count Number of input arguments.
+ * @return Non-zero on success, zero on error.
+ */
+int
+random_seed_set(struct Client* from, const char* const* fields, int count)
+{
+ if (count < 1) {
+ if (from) /* send an error */
+ return need_more_params(from, "SET");
+ else {
+ log_write(LS_CONFIG, L_ERROR, 0, "Not enough fields in F line");
+ return 0;
+ }
+ }
-/* 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 )
+ random_add_entropy(fields[0], strlen(fields[0]));
+ return 1;
+}
-/*
- * 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.
- *
- * original comment left in; this used to be called MD5Transform and took
- * two arguments; I've internalized those arguments, creating the character
- * array "localkey," which should contain 8 bytes of data. The function also
- * originally returned nothing; now it returns an unsigned long that is the
- * random number. It appears to be reallyrandom, so... -Kev
- *
- * I don't really know what this does. I tried to figure it out and got
- * a headache. If you know what's good for you, you'll leave this stuff
- * for the smart people and do something else. -record
+/** Generate a pseudo-random number.
+ * This uses the #localkey structure plus current time as input to
+ * MD5, feeding most of the MD5 output back to #localkey and using one
+ * output words as the pseudo-random output.
+ * @return A 32-bit pseudo-random number.
*/
unsigned int ircrandom(void)
{
- unsigned int a, b, c, d;
- unsigned char in[16];
struct timeval tv;
+ char usec[3];
- gettimeofday(&tv, NULL);
-
- memcpy((void *)in, (void *)localkey, 8);
- memcpy((void *)(in + 8), (void *)&tv.tv_sec, 4);
- memcpy((void *)(in + 12), (void *)&tv.tv_usec, 4);
-
- a = 0x67452301;
- b = 0xefcdab89;
- c = 0x98badcfe;
- d = 0x10325476;
-
- MD5STEP(F1, a, b, c, d, (int)in[0] + 0xd76aa478, 7);
- MD5STEP(F1, d, a, b, c, (int)in[1] + 0xe8c7b756, 12);
- MD5STEP(F1, c, d, a, b, (int)in[2] + 0x242070db, 17);
- MD5STEP(F1, b, c, d, a, (int)in[3] + 0xc1bdceee, 22);
- MD5STEP(F1, a, b, c, d, (int)in[4] + 0xf57c0faf, 7);
- MD5STEP(F1, d, a, b, c, (int)in[5] + 0x4787c62a, 12);
- MD5STEP(F1, c, d, a, b, (int)in[6] + 0xa8304613, 17);
- MD5STEP(F1, b, c, d, a, (int)in[7] + 0xfd469501, 22);
- MD5STEP(F1, a, b, c, d, (int)in[8] + 0x698098d8, 7);
- MD5STEP(F1, d, a, b, c, (int)in[9] + 0x8b44f7af, 12);
- MD5STEP(F1, c, d, a, b, (int)in[10] + 0xffff5bb1, 17);
- MD5STEP(F1, b, c, d, a, (int)in[11] + 0x895cd7be, 22);
- MD5STEP(F1, a, b, c, d, (int)in[12] + 0x6b901122, 7);
- MD5STEP(F1, d, a, b, c, (int)in[13] + 0xfd987193, 12);
- MD5STEP(F1, c, d, a, b, (int)in[14] + 0xa679438e, 17);
- MD5STEP(F1, b, c, d, a, (int)in[15] + 0x49b40821, 22);
-
- MD5STEP(F2, a, b, c, d, (int)in[1] + 0xf61e2562, 5);
- MD5STEP(F2, d, a, b, c, (int)in[6] + 0xc040b340, 9);
- MD5STEP(F2, c, d, a, b, (int)in[11] + 0x265e5a51, 14);
- MD5STEP(F2, b, c, d, a, (int)in[0] + 0xe9b6c7aa, 20);
- MD5STEP(F2, a, b, c, d, (int)in[5] + 0xd62f105d, 5);
- MD5STEP(F2, d, a, b, c, (int)in[10] + 0x02441453, 9);
- MD5STEP(F2, c, d, a, b, (int)in[15] + 0xd8a1e681, 14);
- MD5STEP(F2, b, c, d, a, (int)in[4] + 0xe7d3fbc8, 20);
- MD5STEP(F2, a, b, c, d, (int)in[9] + 0x21e1cde6, 5);
- MD5STEP(F2, d, a, b, c, (int)in[14] + 0xc33707d6, 9);
- MD5STEP(F2, c, d, a, b, (int)in[3] + 0xf4d50d87, 14);
- MD5STEP(F2, b, c, d, a, (int)in[8] + 0x455a14ed, 20);
- MD5STEP(F2, a, b, c, d, (int)in[13] + 0xa9e3e905, 5);
- MD5STEP(F2, d, a, b, c, (int)in[2] + 0xfcefa3f8, 9);
- MD5STEP(F2, c, d, a, b, (int)in[7] + 0x676f02d9, 14);
- MD5STEP(F2, b, c, d, a, (int)in[12] + 0x8d2a4c8a, 20);
+ /* Add some randomness to the pool. */
+ gettimeofday(&tv, 0);
+ usec[0] = tv.tv_usec;
+ usec[1] = tv.tv_usec >> 8;
+ usec[2] = tv.tv_usec >> 16;
+ random_add_entropy(usec, 3);
- MD5STEP(F3, a, b, c, d, (int)in[5] + 0xfffa3942, 4);
- MD5STEP(F3, d, a, b, c, (int)in[8] + 0x8771f681, 11);
- MD5STEP(F3, c, d, a, b, (int)in[11] + 0x6d9d6122, 16);
- MD5STEP(F3, b, c, d, a, (int)in[14] + 0xfde5380c, 23);
- MD5STEP(F3, a, b, c, d, (int)in[1] + 0xa4beea44, 4);
- MD5STEP(F3, d, a, b, c, (int)in[4] + 0x4bdecfa9, 11);
- MD5STEP(F3, c, d, a, b, (int)in[7] + 0xf6bb4b60, 16);
- MD5STEP(F3, b, c, d, a, (int)in[10] + 0xbebfbc70, 23);
- MD5STEP(F3, a, b, c, d, (int)in[13] + 0x289b7ec6, 4);
- MD5STEP(F3, d, a, b, c, (int)in[0] + 0xeaa127fa, 11);
- MD5STEP(F3, c, d, a, b, (int)in[3] + 0xd4ef3085, 16);
- MD5STEP(F3, b, c, d, a, (int)in[6] + 0x04881d05, 23);
- MD5STEP(F3, a, b, c, d, (int)in[9] + 0xd9d4d039, 4);
- MD5STEP(F3, d, a, b, c, (int)in[12] + 0xe6db99e5, 11);
- MD5STEP(F3, c, d, a, b, (int)in[15] + 0x1fa27cf8, 16);
- MD5STEP(F3, b, c, d, a, (int)in[2] + 0xc4ac5665, 23);
+ /* Perform MD5 step. */
+ localkey.buf[0] = 0x67452301;
+ localkey.buf[1] = 0xefcdab89;
+ localkey.buf[2] = 0x98badcfe;
+ localkey.buf[3] = 0x10325476;
+ MD5Transform(localkey.buf, (uint32*)localkey.in);
- MD5STEP(F4, a, b, c, d, (int)in[0] + 0xf4292244, 6);
- MD5STEP(F4, d, a, b, c, (int)in[7] + 0x432aff97, 10);
- MD5STEP(F4, c, d, a, b, (int)in[14] + 0xab9423a7, 15);
- MD5STEP(F4, b, c, d, a, (int)in[5] + 0xfc93a039, 21);
- MD5STEP(F4, a, b, c, d, (int)in[12] + 0x655b59c3, 6);
- MD5STEP(F4, d, a, b, c, (int)in[3] + 0x8f0ccc92, 10);
- MD5STEP(F4, c, d, a, b, (int)in[10] + 0xffeff47d, 15);
- MD5STEP(F4, b, c, d, a, (int)in[1] + 0x85845dd1, 21);
- MD5STEP(F4, a, b, c, d, (int)in[8] + 0x6fa87e4f, 6);
- MD5STEP(F4, d, a, b, c, (int)in[15] + 0xfe2ce6e0, 10);
- MD5STEP(F4, c, d, a, b, (int)in[6] + 0xa3014314, 15);
- MD5STEP(F4, b, c, d, a, (int)in[13] + 0x4e0811a1, 21);
- MD5STEP(F4, a, b, c, d, (int)in[4] + 0xf7537e82, 6);
- MD5STEP(F4, d, a, b, c, (int)in[11] + 0xbd3af235, 10);
- MD5STEP(F4, c, d, a, b, (int)in[2] + 0x2ad7d2bb, 15);
- MD5STEP(F4, b, c, d, a, (int)in[9] + 0xeb86d391, 21);
+ /* Feed back 12 bytes of hash value into randomness pool. */
+ random_add_entropy((char*)localkey.buf, 12);
- /*
- * We have 4 unsigned longs generated by the above sequence; this scrambles
- * them together so that if there is any pattern, it will be obscured.
- */
- return (a ^ b ^ c ^ d);
+ /* Return the final word of hash, which should not provide any
+ * useful insight into current pool contents. */
+ return localkey.buf[3];
}
projects / ircu2.10.12-pk.git / blobdiff