Update OpenSSL DRBG support code. Use date time vector as additional data.

Set FIPS RAND_METHOD at same time as OpenSSL RAND_METHOD.

crypto/rand/rand_lib.c

@@ -65,6 +65,11 @@
 #include <openssl/engine.h>
 #endif
 
+#ifdef OPENSSL_FIPS
+#include <openssl/fips.h>
+#include <openssl/fips_rand.h>
+#endif
+
 #ifndef OPENSSL_NO_ENGINE
 /* non-NULL if default_RAND_meth is ENGINE-provided */
 static ENGINE *funct_ref =NULL;
@@ -73,6 +78,10 @@ static const RAND_METHOD *default_RAND_meth = NULL;
 
 int RAND_set_rand_method(const RAND_METHOD *meth)
 	{
+#ifdef OPENSSL_FIPS
+	if (!FIPS_rand_set_method(meth))
+		return 0;
+#endif
 #ifndef OPENSSL_NO_ENGINE
 	if(funct_ref)
 		{
@@ -178,9 +187,6 @@ int RAND_status(void)
 
 #ifdef OPENSSL_FIPS
 
-#include <openssl/fips.h>
-#include <openssl/fips_rand.h>
-
 /* FIPS DRBG initialisation code. This sets up the DRBG for use by the
  * rest of OpenSSL. 
  */
@@ -210,6 +216,20 @@ static void drbg_free_entropy(DRBG_CTX *ctx, unsigned char *out, size_t olen)
 	OPENSSL_free(out);
 	}
 
+/* Set "additional input" when generating random data. This uses the
+ * current PID, a time value and a counter.
+ */
+
+static size_t drbg_get_adin(DRBG_CTX *ctx, unsigned char **pout)
+    	{
+	/* Use of static variables is OK as this happens under a lock */
+	static unsigned char buf[16];
+	static unsigned long counter;
+	FIPS_get_timevec(buf, &counter);
+	*pout = buf;
+	return sizeof(buf);
+	}
+
 /* RAND_add() and RAND_seed() pass through to OpenSSL PRNG so it is 
  * correctly seeded by RAND_poll().
  */
@@ -228,14 +248,20 @@ static int drbg_rand_seed(DRBG_CTX *ctx, const void *in, int inlen)
 int RAND_init_fips(void)
 	{
 	DRBG_CTX *dctx;
-	unsigned char pers[16] = {0,0,0};
+	size_t plen;
+	unsigned char pers[32], *p;
 	dctx = FIPS_get_default_drbg();
         FIPS_drbg_init(dctx, NID_aes_256_ctr, DRBG_FLAG_CTR_USE_DF);
         FIPS_drbg_set_callbacks(dctx,
 				drbg_get_entropy, drbg_free_entropy,
 				drbg_get_entropy, drbg_free_entropy);
-	FIPS_drbg_set_rand_callbacks(dctx, 0, 0,
+	FIPS_drbg_set_rand_callbacks(dctx, drbg_get_adin, 0,
 					drbg_rand_seed, drbg_rand_add);
+	/* Personalisation string: a string followed by date time vector */
+	strcpy((char *)pers, "OpenSSL DRBG2.0");
+	plen = drbg_get_adin(dctx, &p);
+	memcpy(pers + 16, p, plen);
+
         FIPS_drbg_instantiate(dctx, pers, sizeof(pers));
         FIPS_rand_set_method(FIPS_drbg_method());
 	return 1;

fips/fips.h

@@ -127,6 +127,8 @@ void FIPS_set_malloc_callbacks(
 		void *(*malloc_cb)(int num, const char *file, int line),
 		void (*free_cb)(void *));
 
+void FIPS_get_timevec(unsigned char *buf, unsigned long *pctr);
+
 #define FIPS_ERROR_IGNORED(alg) OpenSSLDie(__FILE__, __LINE__, \
 		alg " previous FIPS forbidden algorithm error ignored");
 

fips/rand/fips_rand.c

@@ -221,14 +221,13 @@ int FIPS_x931_set_dt(unsigned char *dt)
 	return 1;
 	}
 
-static void fips_get_dt(FIPS_PRNG_CTX *ctx)
-    {
+void FIPS_get_timevec(unsigned char *buf, unsigned long *pctr)
+	{
 #ifdef OPENSSL_SYS_WIN32
 	FILETIME ft;
 #else
 	struct timeval tv;
 #endif
-	unsigned char *buf = ctx->DT;
 
 #ifndef GETPID_IS_MEANINGLESS
 	unsigned long pid;
@@ -255,12 +254,12 @@ static void fips_get_dt(FIPS_PRNG_CTX *ctx)
 	buf[6] = (unsigned char) ((tv.tv_usec >> 16) & 0xff);
 	buf[7] = (unsigned char) ((tv.tv_usec >> 24) & 0xff);
 #endif
-	buf[8] = (unsigned char) (ctx->counter & 0xff);
-	buf[9] = (unsigned char) ((ctx->counter >> 8) & 0xff);
-	buf[10] = (unsigned char) ((ctx->counter >> 16) & 0xff);
-	buf[11] = (unsigned char) ((ctx->counter >> 24) & 0xff);
+	buf[8] = (unsigned char) (*pctr & 0xff);
+	buf[9] = (unsigned char) ((*pctr >> 8) & 0xff);
+	buf[10] = (unsigned char) ((*pctr >> 16) & 0xff);
+	buf[11] = (unsigned char) ((*pctr >> 24) & 0xff);
 
-	ctx->counter++;
+	(*pctr)++;
 
 
 #ifndef GETPID_IS_MEANINGLESS
@@ -296,7 +295,7 @@ static int fips_rand(FIPS_PRNG_CTX *ctx,
 	for (;;)
 		{
 		if (!ctx->test_mode)
-			fips_get_dt(ctx);
+			FIPS_get_timevec(ctx->DT, &ctx->counter);
 		AES_encrypt(ctx->DT, I, &ctx->ks);
 		for (i = 0; i < AES_BLOCK_LENGTH; i++)
 			tmp[i] = I[i] ^ ctx->V[i];