genrand.c File Reference

Unix SMB/CIFS implementation. Functions to create reasonable random numbers for crypto use. More...

#include "byteorder.h"
#include "md4.h"
#include "proto.h"
#include "smb.h"
#include <pwd.h>
#include <time.h>
#include <unistd.h>
#include <fcntl.h>

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Macros
#define	uint32   uint32_t
#define	False   0
#define	True   1
#define	ZERO_STRUCT(x)   memset ((char *) &(x), 0, sizeof (x))

Typedefs
typedef unsigned int	bool

Functions
static void	get_rand_reseed_data_ntlmssp (int *reseed_data)
static void	do_filehash_ntlmssp (const char *fname, unsigned char *the_hash)
static int	do_reseed_ntlmssp (bool use_fd, int fd)
void	generate_random_buffer_ntlmssp (unsigned char *out, int len)

Variables
static unsigned char	smb_arc4_state [258]
static uint32	counter
static bool	done_reseed_ntlmssp = False
static void(*	reseed_callback_ntlmssp )(int *newseed)

Detailed Description

Unix SMB/CIFS implementation. Functions to create reasonable random numbers for crypto use.

Random number generation.

Definition in file genrand.c.

Macro Definition Documentation

False

#define False   0

Definition at line 44 of file genrand.c.

True

#define True   1

Definition at line 45 of file genrand.c.

uint32

#define uint32   uint32_t

Definition at line 40 of file genrand.c.

ZERO_STRUCT

#define ZERO_STRUCT

(

x

)

memset ((char *) &(x), 0, sizeof (x))

Definition at line 56 of file genrand.c.

Typedef Documentation

bool

typedef unsigned int bool

Definition at line 43 of file genrand.c.

Function Documentation

do_filehash_ntlmssp()

static void do_filehash_ntlmssp ( const char *  fname, unsigned char *  the_hash  )

static

Definition at line 84 of file genrand.c.

{
  unsigned char buf[1011]; /* deliberate weird size */
  unsigned char tmp_md4[16];
  int fd, n;
 
  fd = open (fname, O_RDONLY, 0);
  if (fd == -1)
    return;
 
  while ((n = read (fd, (char *) buf, sizeof (buf))) > 0)
    {
      mdfour_ntlmssp (tmp_md4, buf, n);
      for (n = 0; n < 16; n++)
        the_hash[n] ^= tmp_md4[n];
    }
  close (fd);
}

References mdfour_ntlmssp().

Referenced by do_reseed_ntlmssp().

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do_reseed_ntlmssp()

static int do_reseed_ntlmssp ( bool  use_fd, int  fd  )

static

Definition at line 116 of file genrand.c.

{
  unsigned char seed_inbuf[40];
  uint32 v1, v2;
  struct timeval tval;
  pid_t mypid;
  int reseed_data = 0;
 
  if (use_fd)
    {
      if (fd != -1)
        return fd;
      fd = open ("/dev/urandom", O_RDONLY, 0);
      if (fd >= 0)
        return fd;
    }
 
  /* Add in some secret file contents */
  memset (seed_inbuf, '\0', sizeof (seed_inbuf));
  do_filehash_ntlmssp ("/etc/shadow", &seed_inbuf[0]);
  /*
   * Add the counter, time of day, and pid.
   */
 
  GetTimeOfDay_ntlmssp (&tval);
  mypid = getpid ();
  v1 = (counter++) + mypid + (uint32) tval.tv_sec;
  v2 = (counter++) * mypid + (uint32) 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_ntlmssp (&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)];
    }
 
  smb_arc4_init_ntlmssp (smb_arc4_state, seed_inbuf, sizeof (seed_inbuf));
 
  return -1;
}

References counter, do_filehash_ntlmssp(), get_rand_reseed_data_ntlmssp(), GetTimeOfDay_ntlmssp(), IVAL, SIVAL, smb_arc4_init_ntlmssp(), smb_arc4_state, timeval(), and uint32.

Referenced by generate_random_buffer_ntlmssp().

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generate_random_buffer_ntlmssp()

void generate_random_buffer_ntlmssp	(	unsigned char *	out,
		int	len
	)

Definition at line 170 of file genrand.c.

{
  static int urand_fd = -1;
  unsigned char md4_buf[64];
  unsigned char tmp_buf[16];
  unsigned char *p;
 
  if (!done_reseed_ntlmssp)
    {
      urand_fd = do_reseed_ntlmssp (True, urand_fd);
      done_reseed_ntlmssp = 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_ntlmssp (False, -1);
      done_reseed_ntlmssp = 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;
 
      bzero (md4_buf, sizeof (md4_buf));
      smb_arc4_crypt_ntlmssp (smb_arc4_state, md4_buf, sizeof (md4_buf));
      mdfour_ntlmssp (tmp_buf, md4_buf, sizeof (md4_buf));
      memcpy (p, tmp_buf, copy_len);
      p += copy_len;
      len -= copy_len;
    }
}

References do_reseed_ntlmssp(), done_reseed_ntlmssp, False, len, mdfour_ntlmssp(), smb_arc4_crypt_ntlmssp(), smb_arc4_state, and True.

Referenced by LMv2_generate_response_ntlmssp(), ntlmssp_genauth_keyexchg(), ntlmssp_genauth_ntlm2(), and NTLMv2_generate_client_data_ntlmssp().

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get_rand_reseed_data_ntlmssp()

static void get_rand_reseed_data_ntlmssp ( int *  reseed_data )

static

Definition at line 66 of file genrand.c.

{
  if (reseed_callback_ntlmssp)
    {
      reseed_callback_ntlmssp (reseed_data);
    }
  else
    {
      *reseed_data = 0;
    }
}

References reseed_callback_ntlmssp.

Referenced by do_reseed_ntlmssp().

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Variable Documentation

counter

uint32 counter

static

Definition at line 48 of file genrand.c.

Referenced by do_reseed_ntlmssp(), and ftp_log_in().

done_reseed_ntlmssp

bool done_reseed_ntlmssp = False

static

Definition at line 58 of file genrand.c.

Referenced by generate_random_buffer_ntlmssp().

reseed_callback_ntlmssp

void(* reseed_callback_ntlmssp) (int *newseed)

static

Definition at line 59 of file genrand.c.

Referenced by get_rand_reseed_data_ntlmssp().

smb_arc4_state

unsigned char smb_arc4_state[258]

static

Definition at line 47 of file genrand.c.

Referenced by do_reseed_ntlmssp(), and generate_random_buffer_ntlmssp().