+++ /dev/null
-/*
- Unix SMB/CIFS implementation.
-
- Functions to create reasonable random numbers for crypto use.
-
- Copyright (C) Jeremy Allison 2001
-
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 3 of the License, or
- (at your option) any later version.
-
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>.
-*/
-
-#include "includes.h"
-
-static struct arcfour_state smb_arc4_state;
-static uint32 counter;
-
-static bool done_reseed = False;
-static void (*reseed_callback)(int *newseed);
-
-/****************************************************************
- Copy any user given reseed data.
-*****************************************************************/
-
-void set_rand_reseed_callback(void (*fn)(int *))
-{
- reseed_callback = fn;
- set_need_random_reseed();
-}
-
-void set_need_random_reseed(void)
-{
- done_reseed = False;
-}
-
-static void get_rand_reseed_data(int *reseed_data)
-{
- if (reseed_callback) {
- reseed_callback(reseed_data);
- } else {
- *reseed_data = 0;
- }
-}
-
-/****************************************************************
- Get a 16 byte hash from the contents of a file.
- Note that the hash is not initialised.
-*****************************************************************/
-
-static void do_filehash(const char *fname, unsigned char *the_hash)
-{
- unsigned char buf[1011]; /* deliberate weird size */
- unsigned char tmp_md4[16];
- int fd, n;
-
- fd = sys_open(fname,O_RDONLY,0);
- if (fd == -1)
- return;
-
- while ((n = read(fd, (char *)buf, sizeof(buf))) > 0) {
- mdfour(tmp_md4, buf, n);
- for (n=0;n<16;n++)
- the_hash[n] ^= tmp_md4[n];
- }
- close(fd);
-}
-
-/**************************************************************
- Try and get a good random number seed. Try a number of
- different factors. Firstly, try /dev/urandom - use if exists.
-
- We use /dev/urandom as a read of /dev/random can block if
- the entropy pool dries up. This leads clients to timeout
- or be very slow on connect.
-
- If we can't use /dev/urandom then seed the stream random generator
- above...
-**************************************************************/
-
-static int do_reseed(bool use_fd, int fd)
-{
- unsigned char seed_inbuf[40];
- DATA_BLOB seed_blob = { seed_inbuf, 40 };
- uint32 v1, v2; struct timeval tval; pid_t mypid;
- struct passwd *pw;
- int reseed_data = 0;
-
- if (use_fd) {
- if (fd != -1)
- return fd;
-
- fd = sys_open( "/dev/urandom", O_RDONLY,0);
- if(fd >= 0)
- return fd;
- }
-
- /* Add in some secret file contents */
-
- do_filehash("/etc/shadow", &seed_inbuf[0]);
- do_filehash(lp_smb_passwd_file(), &seed_inbuf[16]);
-
- /*
- * Add in the root encrypted password.
- * On any system where security is taken
- * seriously this will be secret.
- */
-
- pw = getpwnam_alloc(NULL, "root");
- if (pw && pw->pw_passwd) {
- size_t i;
- unsigned char md4_tmp[16];
- mdfour(md4_tmp, (unsigned char *)pw->pw_passwd, strlen(pw->pw_passwd));
- for (i=0;i<16;i++)
- seed_inbuf[8+i] ^= md4_tmp[i];
- TALLOC_FREE(pw);
- }
-
- /*
- * Add the counter, time of day, and pid.
- */
-
- GetTimeOfDay(&tval);
- mypid = sys_getpid();
- v1 = (counter++) + mypid + tval.tv_sec;
- v2 = (counter++) * mypid + tval.tv_usec;
-
- SIVAL(seed_inbuf, 32, v1 ^ IVAL(seed_inbuf, 32));
- SIVAL(seed_inbuf, 36, v2 ^ IVAL(seed_inbuf, 36));
-
- /*
- * Add any user-given reseed data.
- */
-
- get_rand_reseed_data(&reseed_data);
- if (reseed_data) {
- size_t i;
- for (i = 0; i < sizeof(seed_inbuf); i++)
- seed_inbuf[i] ^= ((char *)(&reseed_data))[i % sizeof(reseed_data)];
- }
-
- arcfour_init(&smb_arc4_state, &seed_blob);
-
- return -1;
-}
-
-/*******************************************************************
- Interface to the (hopefully) good crypto random number generator.
-********************************************************************/
-
-void generate_random_buffer(uint8_t *out, int len)
-{
- static int urand_fd = -1;
- unsigned char md4_buf[64];
- unsigned char tmp_buf[16];
- unsigned char *p;
-
- if(!done_reseed) {
- urand_fd = do_reseed(True, urand_fd);
- done_reseed = True;
- }
-
- if (urand_fd != -1 && len > 0) {
-
- if (read(urand_fd, out, len) == len)
- return; /* len bytes of random data read from urandom. */
-
- /* Read of urand error, drop back to non urand method. */
- close(urand_fd);
- urand_fd = -1;
- do_reseed(False, -1);
- done_reseed = True;
- }
-
- /*
- * Generate random numbers in chunks of 64 bytes,
- * then md4 them & copy to the output buffer.
- * This way the raw state of the stream is never externally
- * seen.
- */
-
- p = out;
- while(len > 0) {
- int copy_len = len > 16 ? 16 : len;
-
- arcfour_crypt_sbox(&smb_arc4_state, md4_buf, sizeof(md4_buf));
- mdfour(tmp_buf, md4_buf, sizeof(md4_buf));
- memcpy(p, tmp_buf, copy_len);
- p += copy_len;
- len -= copy_len;
- }
-}
-
-/*******************************************************************
- Use the random number generator to generate a random string.
-********************************************************************/
-
-static char c_list[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+_-#.,";
-
-char *generate_random_str(TALLOC_CTX *mem_ctx, size_t len)
-{
- unsigned char *retstr = talloc_zero_array(mem_ctx, unsigned char, len);
- size_t i;
-
- generate_random_buffer( retstr, len);
- for (i = 0; i < len; i++)
- retstr[i] = c_list[ retstr[i] % (sizeof(c_list)-1) ];
-
- retstr[i] = '\0';
-
- return (char *)retstr;
-}
git.samba.org / nivanova / samba-autobuild / .git / commitdiff