Improved error checking for DRBG calls.

New functionality to allow default DRBG type to be set during compilation or during runtime.

3 files changed, 34 insertions, 2 deletions

diff --git a/crypto/rand/rand.h b/crypto/rand/rand.h
index 315b5cc016..dc8fcf94c5 100644
--- a/crypto/rand/rand.h
+++ b/crypto/rand/rand.h
@@ -120,6 +120,7 @@ int RAND_event(UINT, WPARAM, LPARAM);
 #endif
 
 #ifdef OPENSSL_FIPS
+void RAND_set_fips_drbg_type(int type, int flags);
 int RAND_init_fips(void);
 #endif
 
@@ -133,9 +134,12 @@ void ERR_load_RAND_strings(void);
 
 /* Function codes. */
 #define RAND_F_RAND_GET_RAND_METHOD			 101
+#define RAND_F_RAND_INIT_FIPS				 102
 #define RAND_F_SSLEAY_RAND_BYTES			 100
 
 /* Reason codes. */
+#define RAND_R_ERROR_INITIALISING_DRBG			 102
+#define RAND_R_ERROR_INSTANTIATING_DRBG			 103
 #define RAND_R_NO_FIPS_RANDOM_METHOD_SET		 101
 #define RAND_R_PRNG_NOT_SEEDED				 100
 
diff --git a/crypto/rand/rand_err.c b/crypto/rand/rand_err.c
index 672c333133..b8586c8f4a 100644
--- a/crypto/rand/rand_err.c
+++ b/crypto/rand/rand_err.c
@@ -71,12 +71,15 @@
 static ERR_STRING_DATA RAND_str_functs[]=
 	{
 {ERR_FUNC(RAND_F_RAND_GET_RAND_METHOD),	"RAND_get_rand_method"},
+{ERR_FUNC(RAND_F_RAND_INIT_FIPS),	"RAND_init_fips"},
 {ERR_FUNC(RAND_F_SSLEAY_RAND_BYTES),	"SSLEAY_RAND_BYTES"},
 {0,NULL}
 	};
 
 static ERR_STRING_DATA RAND_str_reasons[]=
 	{
+{ERR_REASON(RAND_R_ERROR_INITIALISING_DRBG),"error initialising drbg"},
+{ERR_REASON(RAND_R_ERROR_INSTANTIATING_DRBG),"error instantiating drbg"},
 {ERR_REASON(RAND_R_NO_FIPS_RANDOM_METHOD_SET),"no fips random method set"},
 {ERR_REASON(RAND_R_PRNG_NOT_SEEDED)      ,"PRNG not seeded"},
 {0,NULL}
diff --git a/crypto/rand/rand_lib.c b/crypto/rand/rand_lib.c
index 653896b4b7..daf1dab973 100644
--- a/crypto/rand/rand_lib.c
+++ b/crypto/rand/rand_lib.c
@@ -245,13 +245,34 @@ static int drbg_rand_seed(DRBG_CTX *ctx, const void *in, int inlen)
 	return 1;
 	}
 
+#ifndef OPENSSL_DRBG_DEFAULT_TYPE
+#define OPENSSL_DRBG_DEFAULT_TYPE	NID_aes_256_ctr
+#endif
+#ifndef OPENSSL_DRBG_DEFAULT_FLAGS
+#define OPENSSL_DRBG_DEFAULT_FLAGS	DRBG_FLAG_CTR_USE_DF
+#endif 
+
+static int fips_drbg_type = OPENSSL_DRBG_DEFAULT_TYPE;
+static int fips_drbg_flags = OPENSSL_DRBG_DEFAULT_FLAGS;
+
+void RAND_set_fips_drbg_type(int type, int flags)
+	{
+	fips_drbg_type = type;
+	fips_drbg_flags = flags;
+	}
+
 int RAND_init_fips(void)
 	{
 	DRBG_CTX *dctx;
 	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);
+        if (FIPS_drbg_init(dctx, fips_drbg_type, fips_drbg_flags) <= 0)
+		{
+		RANDerr(RAND_F_RAND_INIT_FIPS, RAND_R_ERROR_INITIALISING_DRBG);
+		return 0;
+		}
+		
         FIPS_drbg_set_callbacks(dctx,
 				drbg_get_entropy, drbg_free_entropy, 20,
 				drbg_get_entropy, drbg_free_entropy);
@@ -262,7 +283,11 @@ int RAND_init_fips(void)
 	plen = drbg_get_adin(dctx, &p);
 	memcpy(pers + 16, p, plen);
 
-        FIPS_drbg_instantiate(dctx, pers, sizeof(pers));
+        if (FIPS_drbg_instantiate(dctx, pers, sizeof(pers)) <= 0)
+		{
+		RANDerr(RAND_F_RAND_INIT_FIPS, RAND_R_ERROR_INSTANTIATING_DRBG);
+		return 0;
+		}
         FIPS_rand_set_method(FIPS_drbg_method());
 	return 1;
 	}