From 39a1894bf46b6ca6796e496cad972759fe11d082 Mon Sep 17 00:00:00 2001 From: Volker Lendecke Date: Tue, 23 Jun 2015 09:02:46 +0200 Subject: [PATCH] lib: Strip genrand.c a bit This moves for example password complexity checks out of the core random number generator Signed-off-by: Volker Lendecke Reviewed-by: Jeremy Allison --- lib/util/genrand.c | 280 --------------------------------- lib/util/{genrand.c => genrand_util.c} | 269 +------------------------------ lib/util/wscript_build | 2 +- 3 files changed, 8 insertions(+), 543 deletions(-) copy lib/util/{genrand.c => genrand_util.c} (53%) diff --git a/lib/util/genrand.c b/lib/util/genrand.c index c0163f4e37d..4f328eac3d0 100644 --- a/lib/util/genrand.c +++ b/lib/util/genrand.c @@ -283,283 +283,3 @@ _PUBLIC_ void generate_secret_buffer(uint8_t *out, int len) generate_random_buffer(out, len); } - -/** - generate a single random uint32_t -**/ -_PUBLIC_ uint32_t generate_random(void) -{ - uint8_t v[4]; - generate_random_buffer(v, 4); - return IVAL(v, 0); -} - - -/** - Microsoft composed the following rules (among others) for quality - checks. This is an abridgment from - http://msdn.microsoft.com/en-us/subscriptions/cc786468%28v=ws.10%29.aspx: - - Passwords must contain characters from three of the following five - categories: - - - Uppercase characters of European languages (A through Z, with - diacritic marks, Greek and Cyrillic characters) - - Lowercase characters of European languages (a through z, sharp-s, - with diacritic marks, Greek and Cyrillic characters) - - Base 10 digits (0 through 9) - - Nonalphanumeric characters: ~!@#$%^&*_-+=`|\(){}[]:;"'<>,.?/ - - Any Unicode character that is categorized as an alphabetic character - but is not uppercase or lowercase. This includes Unicode characters - from Asian languages. - - Note: for now do not check if the unicode category is - alphabetic character -**/ -_PUBLIC_ bool check_password_quality(const char *pwd) -{ - size_t ofs = 0; - size_t num_chars = 0; - size_t num_digits = 0; - size_t num_upper = 0; - size_t num_lower = 0; - size_t num_nonalpha = 0; - size_t num_unicode = 0; - size_t num_categories = 0; - - if (pwd == NULL) { - return false; - } - - while (true) { - const char *s = &pwd[ofs]; - size_t len = 0; - codepoint_t c; - - c = next_codepoint(s, &len); - if (c == INVALID_CODEPOINT) { - return false; - } else if (c == 0) { - break; - } - ofs += len; - num_chars += 1; - - if (len == 1) { - const char *na = "~!@#$%^&*_-+=`|\\(){}[]:;\"'<>,.?/"; - - if (isdigit(c)) { - num_digits += 1; - continue; - } - - if (isupper(c)) { - num_upper += 1; - continue; - } - - if (islower(c)) { - num_lower += 1; - continue; - } - - if (strchr(na, c)) { - num_nonalpha += 1; - continue; - } - - /* - * the rest does not belong to - * a category. - */ - continue; - } - - if (isupper_m(c)) { - num_upper += 1; - continue; - } - - if (islower_m(c)) { - num_lower += 1; - continue; - } - - /* - * Note: for now do not check if the unicode category is - * alphabetic character - * - * We would have to import the details from - * ftp://ftp.unicode.org/Public/6.3.0/ucd/UnicodeData-6.3.0d1.txt - */ - num_unicode += 1; - continue; - } - - if (num_digits > 0) { - num_categories += 1; - } - if (num_upper > 0) { - num_categories += 1; - } - if (num_lower > 0) { - num_categories += 1; - } - if (num_nonalpha > 0) { - num_categories += 1; - } - if (num_unicode > 0) { - num_categories += 1; - } - - if (num_categories >= 3) { - return true; - } - - return false; -} - -/** - Use the random number generator to generate a random string. -**/ - -_PUBLIC_ char *generate_random_str_list(TALLOC_CTX *mem_ctx, size_t len, const char *list) -{ - size_t i; - size_t list_len = strlen(list); - - char *retstr = talloc_array(mem_ctx, char, len + 1); - if (!retstr) return NULL; - - generate_random_buffer((uint8_t *)retstr, len); - for (i = 0; i < len; i++) { - retstr[i] = list[retstr[i] % list_len]; - } - retstr[i] = '\0'; - - return retstr; -} - -/** - * Generate a random text string consisting of the specified length. - * The returned string will be allocated. - * - * Characters used are: ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+_-#., - */ - -_PUBLIC_ char *generate_random_str(TALLOC_CTX *mem_ctx, size_t len) -{ - char *retstr; - const char *c_list = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+_-#.,"; - -again: - retstr = generate_random_str_list(mem_ctx, len, c_list); - if (!retstr) return NULL; - - /* we need to make sure the random string passes basic quality tests - or it might be rejected by windows as a password */ - if (len >= 7 && !check_password_quality(retstr)) { - talloc_free(retstr); - goto again; - } - - return retstr; -} - -/** - * Generate a random text password. - */ - -_PUBLIC_ char *generate_random_password(TALLOC_CTX *mem_ctx, size_t min, size_t max) -{ - char *retstr; - /* This list does not include { or } because they cause - * problems for our provision (it can create a substring - * ${...}, and for Fedora DS (which treats {...} at the start - * of a stored password as special - * -- Andrew Bartlett 2010-03-11 - */ - const char *c_list = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+_-#.,@$%&!?:;<=>()[]~"; - size_t len = max; - size_t diff; - - if (min > max) { - errno = EINVAL; - return NULL; - } - - diff = max - min; - - if (diff > 0 ) { - size_t tmp; - - generate_random_buffer((uint8_t *)&tmp, sizeof(tmp)); - - tmp %= diff; - - len = min + tmp; - } - -again: - retstr = generate_random_str_list(mem_ctx, len, c_list); - if (!retstr) return NULL; - - /* we need to make sure the random string passes basic quality tests - or it might be rejected by windows as a password */ - if (len >= 7 && !check_password_quality(retstr)) { - talloc_free(retstr); - goto again; - } - - return retstr; -} - -/** - * Generate an array of unique text strings all of the same length. - * The returned string will be allocated. - * Returns NULL if the number of unique combinations cannot be created. - * - * Characters used are: abcdefghijklmnopqrstuvwxyz0123456789+_-#., - */ -_PUBLIC_ char** generate_unique_strs(TALLOC_CTX *mem_ctx, size_t len, - uint32_t num) -{ - const char *c_list = "abcdefghijklmnopqrstuvwxyz0123456789+_-#.,"; - const unsigned c_size = 42; - size_t i, j; - unsigned rem; - char ** strs = NULL; - - if (num == 0 || len == 0) - return NULL; - - strs = talloc_array(mem_ctx, char *, num); - if (strs == NULL) return NULL; - - for (i = 0; i < num; i++) { - char *retstr = (char *)talloc_size(strs, len + 1); - if (retstr == NULL) { - talloc_free(strs); - return NULL; - } - rem = i; - for (j = 0; j < len; j++) { - retstr[j] = c_list[rem % c_size]; - rem = rem / c_size; - } - retstr[j] = 0; - strs[i] = retstr; - if (rem != 0) { - /* we were not able to fit the number of - * combinations asked for in the length - * specified */ - DEBUG(0,(__location__ ": Too many combinations %u for length %u\n", - num, (unsigned)len)); - - talloc_free(strs); - return NULL; - } - } - - return strs; -} diff --git a/lib/util/genrand.c b/lib/util/genrand_util.c similarity index 53% copy from lib/util/genrand.c copy to lib/util/genrand_util.c index c0163f4e37d..af7aab6551d 100644 --- a/lib/util/genrand.c +++ b/lib/util/genrand_util.c @@ -1,20 +1,20 @@ -/* +/* 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 . */ @@ -29,261 +29,6 @@ * @brief Random number generation */ -static unsigned char hash[258]; -static uint32_t counter; - -static bool done_reseed = false; -static unsigned int bytes_since_reseed = 0; - -static int urand_fd = -1; - -static void (*reseed_callback)(void *userdata, int *newseed); -static void *reseed_callback_userdata = NULL; - -/** - Copy any user given reseed data. -**/ - -_PUBLIC_ void set_rand_reseed_callback(void (*fn)(void *, int *), void *userdata) -{ - reseed_callback = fn; - reseed_callback_userdata = userdata; - set_need_random_reseed(); -} - -/** - * Tell the random number generator it needs to reseed. - */ -_PUBLIC_ void set_need_random_reseed(void) -{ - done_reseed = false; - bytes_since_reseed = 0; -} - -static void get_rand_reseed_data(int *reseed_data) -{ - if (reseed_callback) { - reseed_callback(reseed_callback_userdata, reseed_data); - } else { - *reseed_data = 0; - } -} - -/**************************************************************** - Setup the seed. -*****************************************************************/ - -static void seed_random_stream(unsigned char *seedval, size_t seedlen) -{ - unsigned char j = 0; - size_t ind; - - for (ind = 0; ind < 256; ind++) - hash[ind] = (unsigned char)ind; - - for( ind = 0; ind < 256; ind++) { - unsigned char tc; - - j += (hash[ind] + seedval[ind%seedlen]); - - tc = hash[ind]; - hash[ind] = hash[j]; - hash[j] = tc; - } - - hash[256] = 0; - hash[257] = 0; -} - -/**************************************************************** - Get datasize bytes worth of random data. -*****************************************************************/ - -static void get_random_stream(unsigned char *data, size_t datasize) -{ - unsigned char index_i = hash[256]; - unsigned char index_j = hash[257]; - size_t ind; - - for( ind = 0; ind < datasize; ind++) { - unsigned char tc; - unsigned char t; - - index_i++; - index_j += hash[index_i]; - - tc = hash[index_i]; - hash[index_i] = hash[index_j]; - hash[index_j] = tc; - - t = hash[index_i] + hash[index_j]; - data[ind] = hash[t]; - } - - hash[256] = index_i; - hash[257] = index_j; -} - -/**************************************************************** - Get a 16 byte hash from the contents of a file. - - Note that the hash is initialised, because the extra entropy is not - worth the valgrind pain. -*****************************************************************/ - -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; - - ZERO_STRUCT(tmp_md4); - - fd = 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(int fd) -{ - unsigned char seed_inbuf[40]; - uint32_t v1, v2; struct timeval tval; pid_t mypid; - int reseed_data = 0; - - if (fd == -1) { - fd = open( "/dev/urandom", O_RDONLY,0); - if (fd != -1) { - smb_set_close_on_exec(fd); - } - } - if (fd != -1 - && (read(fd, seed_inbuf, sizeof(seed_inbuf)) == sizeof(seed_inbuf))) { - seed_random_stream(seed_inbuf, sizeof(seed_inbuf)); - return fd; - } - - /* Add in some secret file contents */ - - do_filehash("/etc/shadow", &seed_inbuf[0]); - - /* - * Add the counter, time of day, and pid. - */ - - GetTimeOfDay(&tval); - mypid = 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)]; - } - - seed_random_stream(seed_inbuf, sizeof(seed_inbuf)); - - return -1; -} - -/** - Interface to the (hopefully) good crypto random number generator. - Will use our internal PRNG if more than 40 bytes of random generation - has been requested, otherwise tries to read from /dev/random -**/ -_PUBLIC_ void generate_random_buffer(uint8_t *out, int len) -{ - unsigned char md4_buf[64]; - unsigned char tmp_buf[16]; - unsigned char *p; - - if(!done_reseed) { - bytes_since_reseed += len; - - /* Magic constant to try and avoid reading 40 bytes - * and setting up the PRNG if the app only ever wants - * a few bytes */ - if (bytes_since_reseed < 40) { - if (urand_fd == -1) { - urand_fd = open( "/dev/urandom", O_RDONLY,0); - if (urand_fd != -1) { - smb_set_close_on_exec(urand_fd); - } - } - if(urand_fd != -1 && (read(urand_fd, out, len) == len)) { - return; - } - } - - urand_fd = do_reseed(urand_fd); - 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; - - get_random_stream(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; - } -} - -/** - Interface to the (hopefully) good crypto random number generator. - Will always use /dev/urandom if available. -**/ -_PUBLIC_ void generate_secret_buffer(uint8_t *out, int len) -{ - if (urand_fd == -1) { - urand_fd = open( "/dev/urandom", O_RDONLY,0); - if (urand_fd != -1) { - smb_set_close_on_exec(urand_fd); - } - } - if(urand_fd != -1 && (read(urand_fd, out, len) == len)) { - return; - } - - generate_random_buffer(out, len); -} - /** generate a single random uint32_t **/ @@ -476,7 +221,7 @@ _PUBLIC_ char *generate_random_password(TALLOC_CTX *mem_ctx, size_t min, size_t /* This list does not include { or } because they cause * problems for our provision (it can create a substring * ${...}, and for Fedora DS (which treats {...} at the start - * of a stored password as special + * of a stored password as special * -- Andrew Bartlett 2010-03-11 */ const char *c_list = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+_-#.,@$%&!?:;<=>()[]~"; @@ -555,9 +300,9 @@ _PUBLIC_ char** generate_unique_strs(TALLOC_CTX *mem_ctx, size_t len, * specified */ DEBUG(0,(__location__ ": Too many combinations %u for length %u\n", num, (unsigned)len)); - + talloc_free(strs); - return NULL; + return NULL; } } diff --git a/lib/util/wscript_build b/lib/util/wscript_build index 92f25455b82..ffd1098970c 100755 --- a/lib/util/wscript_build +++ b/lib/util/wscript_build @@ -65,7 +65,7 @@ if not bld.env.SAMBA_UTIL_CORE_ONLY: bld.SAMBA_LIBRARY('samba-util', source='''talloc_stack.c smb_threads.c rbtree.c rfc1738.c become_daemon.c system.c select.c getpass.c - genrand.c fsusage.c + genrand.c genrand_util.c fsusage.c params.c util_id.c util_net.c util_strlist.c util_paths.c idtree_random.c base64.c util_str.c util_str_common.c ms_fnmatch.c -- 2.11.4.GIT