[patch 5/6] pseudo random bytes

Reserve px_get_random_bytes() for strong randomness,
add new function px_get_pseudo_random_bytes() for
weak randomness and use it in gen_salt().

On openssl case, use RAND_pseudo_bytes() for
px_get_pseudo_random_bytes().

Final result is that is user has not configured random
souce but kept the 'silly' one, gen_salt() keeps
working, but pgp_encrypt() will throw error.

Index: pgsql/contrib/pgcrypto/px-crypt.c
===================================================================
*** pgsql.orig/contrib/pgcrypto/px-crypt.c
--- pgsql/contrib/pgcrypto/px-crypt.c
*************** px_gen_salt(const char *salt_type, char
*** 171,177 ****
return PXE_BAD_SALT_ROUNDS;
}

! res = px_get_random_bytes(rbuf, g->input_len);
if (res < 0)
return res;

--- 171,177 ----
return PXE_BAD_SALT_ROUNDS;
}

! res = px_get_pseudo_random_bytes(rbuf, g->input_len);
if (res < 0)
return res;

Index: pgsql/contrib/pgcrypto/px.h
===================================================================
*** pgsql.orig/contrib/pgcrypto/px.h
--- pgsql/contrib/pgcrypto/px.h
*************** void px_free(void *p);
*** 83,88 ****
--- 83,89 ----
#define PXE_UNKNOWN_SALT_ALGO -14
#define PXE_BAD_SALT_ROUNDS -15
#define PXE_MCRYPT_INTERNAL -16
+ #define PXE_NO_RANDOM -17

typedef struct px_digest PX_MD;
typedef struct px_alias PX_Alias;
*************** int px_find_cipher(const char *name, P
*** 168,173 ****
--- 169,175 ----
int px_find_combo(const char *name, PX_Combo ** res);

int px_get_random_bytes(uint8 *dst, unsigned count);
+ int px_get_pseudo_random_bytes(uint8 *dst, unsigned count);

const char *px_strerror(int err);

Index: pgsql/contrib/pgcrypto/random.c
===================================================================
*** pgsql.orig/contrib/pgcrypto/random.c
--- pgsql/contrib/pgcrypto/random.c
*************** px_get_random_bytes(uint8 *dst, unsigned
*** 78,87 ****
return res;
}

#elif defined(RAND_SILLY)

int
! px_get_random_bytes(uint8 *dst, unsigned count)
{
int i;

--- 78,93 ----
return res;
}

+ int
+ px_get_pseudo_random_bytes(uint8 *dst, unsigned count)
+ {
+ return px_get_random_bytes(dst, count);
+ }
+
#elif defined(RAND_SILLY)

int
! px_get_pseudo_random_bytes(uint8 *dst, unsigned count)
{
int i;

*************** px_get_random_bytes(uint8 *dst, unsigned
*** 90,95 ****
--- 96,107 ----
return i;
}

+ int
+ px_get_random_bytes(uint8 *dst, unsigned count)
+ {
+ return PXE_NO_RANDOM;
+ }
+
#elif defined(RAND_OPENSSL)

#include <openssl/evp.h>
*************** px_get_random_bytes(uint8 *dst, unsigned
*** 99,120 ****

static int openssl_random_init = 0;

int
px_get_random_bytes(uint8 *dst, unsigned count)
{
int res;

if (!openssl_random_init)
! {
! if (RAND_get_rand_method() == NULL)
! RAND_set_rand_method(RAND_SSLeay());
! openssl_random_init = 1;
! }
!
! /*
! * OpenSSL random should re-feeded occasionally. From /dev/urandom
! * preferably.
! */

res = RAND_bytes(dst, count);
if (res == 1)
--- 111,134 ----

static int openssl_random_init = 0;

+ /*
+ * OpenSSL random should re-feeded occasionally. From /dev/urandom
+ * preferably.
+ */
+ static void init_openssl()
+ {
+ if (RAND_get_rand_method() == NULL)
+ RAND_set_rand_method(RAND_SSLeay());
+ openssl_random_init = 1;
+ }
+
int
px_get_random_bytes(uint8 *dst, unsigned count)
{
int res;

if (!openssl_random_init)
! init_openssl();

res = RAND_bytes(dst, count);
if (res == 1)
*************** px_get_random_bytes(uint8 *dst, unsigned
*** 123,128 ****
--- 137,157 ----
return PXE_OSSL_RAND_ERROR;
}

+ int
+ px_get_pseudo_random_bytes(uint8 *dst, unsigned count)
+ {
+ int res;
+
+ if (!openssl_random_init)
+ init_openssl();
+
+ res = RAND_pseudo_bytes(dst, count);
+ if (res == 0 || res == 1)
+ return count;
+
+ return PXE_OSSL_RAND_ERROR;
+ }
+
#else
#error "Invalid random source"
#endif
Index: pgsql/contrib/pgcrypto/px.c
===================================================================
*** pgsql.orig/contrib/pgcrypto/px.c
--- pgsql/contrib/pgcrypto/px.c
*************** static const struct error_desc px_err_li
*** 56,61 ****
--- 56,62 ----
{PXE_UNKNOWN_SALT_ALGO, "Unknown salt algorithm"},
{PXE_BAD_SALT_ROUNDS, "Incorrect number of rounds"},
{PXE_MCRYPT_INTERNAL, "mcrypt internal error"},
+ {PXE_NO_RANDOM, "No strong random source"},
{0, NULL},
};

--