#include "replace.h"
#include "system/filesys.h"
-#include "../lib/crypto/crypto.h"
#include "lib/util/genrand.h"
+#include "sys_rw_data.h"
#include "lib/util/blocking.h"
-#include "lib/util/time_basic.h"
-#include "lib/util/byteorder.h"
-
-/**
- * @file
- * @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)
+static void open_urandom(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)
+ if (urand_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)];
+ urand_fd = open( "/dev/urandom", O_RDONLY,0);
+ if (urand_fd == -1) {
+ abort();
}
-
- seed_random_stream(seed_inbuf, sizeof(seed_inbuf));
-
- return -1;
+ smb_set_close_on_exec(urand_fd);
}
-/**
- 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.
- */
+ ssize_t rw_ret;
- p = out;
- while(len > 0) {
- int copy_len = len > 16 ? 16 : len;
+ open_urandom();
- 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;
+ rw_ret = read_data(urand_fd, out, len);
+ if (rw_ret != len) {
+ abort();
}
}
-/**
- Interface to the (hopefully) good crypto random number generator.
- Will always use /dev/urandom if available.
-**/
+/*
+ * Keep generate_secret_buffer in case we ever want to do something
+ * different
+ */
_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);
}
git.samba.org / samba.git / blobdiff