Extensive reorganisation of PRNG handling in FIPS module: all calls

now use an internal RAND_METHOD. All dependencies to OpenSSL standard
PRNG are now removed: it is the applications resposibility to setup
the FIPS PRNG and initalise it.

Initial OpenSSL RAND_init_fips() function that will setup the DRBG
for the "FIPS capable OpenSSL".

3 files changed, 74 insertions, 6 deletions

diff --git a/crypto/rand/rand.h b/crypto/rand/rand.h
index 8db2a5f80f..d446c38daf 100644
--- a/crypto/rand/rand.h
+++ b/crypto/rand/rand.h
@@ -94,7 +94,7 @@ extern int rand_predictable;
 
 int RAND_set_rand_method(const RAND_METHOD *meth);
 const RAND_METHOD *RAND_get_rand_method(void);
-#if !defined(OPENSSL_NO_ENGINE) && !defined(OPENSSL_FIPS)
+#ifndef OPENSSL_NO_ENGINE
 int RAND_set_rand_engine(ENGINE *engine);
 #endif
 RAND_METHOD *RAND_SSLeay(void);
@@ -119,6 +119,10 @@ int RAND_event(UINT, WPARAM, LPARAM);
 
 #endif
 
+#ifdef OPENSSL_FIPS
+int RAND_init_fips(void);
+#endif
+
 /* BEGIN ERROR CODES */
 /* The following lines are auto generated by the script mkerr.pl. Any changes
  * made after this point may be overwritten when the script is next run.
@@ -132,6 +136,7 @@ void ERR_load_RAND_strings(void);
 #define RAND_F_FIPS_RAND_SET_DT				 103
 #define RAND_F_FIPS_SET_PRNG_SEED			 104
 #define RAND_F_FIPS_SET_TEST_MODE			 105
+#define RAND_F_FIPS_X931_SET_DT				 106
 #define RAND_F_RAND_GET_RAND_METHOD			 101
 #define RAND_F_SSLEAY_RAND_BYTES			 100
 
diff --git a/crypto/rand/rand_err.c b/crypto/rand/rand_err.c
index 1997752d14..a435b0bfa6 100644
--- a/crypto/rand/rand_err.c
+++ b/crypto/rand/rand_err.c
@@ -74,6 +74,7 @@ static ERR_STRING_DATA RAND_str_functs[]=
 {ERR_FUNC(RAND_F_FIPS_RAND_SET_DT),	"FIPS_RAND_SET_DT"},
 {ERR_FUNC(RAND_F_FIPS_SET_PRNG_SEED),	"FIPS_SET_PRNG_SEED"},
 {ERR_FUNC(RAND_F_FIPS_SET_TEST_MODE),	"FIPS_SET_TEST_MODE"},
+{ERR_FUNC(RAND_F_FIPS_X931_SET_DT),	"FIPS_x931_set_dt"},
 {ERR_FUNC(RAND_F_RAND_GET_RAND_METHOD),	"RAND_get_rand_method"},
 {ERR_FUNC(RAND_F_SSLEAY_RAND_BYTES),	"SSLEAY_RAND_BYTES"},
 {0,NULL}
diff --git a/crypto/rand/rand_lib.c b/crypto/rand/rand_lib.c
index 3cf9ed5050..ef10dd507e 100644
--- a/crypto/rand/rand_lib.c
+++ b/crypto/rand/rand_lib.c
@@ -61,11 +61,6 @@
 #include "cryptlib.h"
 #include <openssl/rand.h>
 
-#ifdef OPENSSL_FIPSCANISTER
-#define OPENSSL_NO_ENGINE
-#include <openssl/fips.h>
-#endif
-
 #ifndef OPENSSL_NO_ENGINE
 #include <openssl/engine.h>
 #endif
@@ -180,3 +175,70 @@ int RAND_status(void)
 		return meth->status();
 	return 0;
 	}
+
+#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. 
+ */
+
+/* Entropy gatherer: use standard OpenSSL PRNG to seed (this will gather
+ * entropy internally through RAND_poll().
+ */
+
+static size_t drbg_get_entropy(DRBG_CTX *ctx, unsigned char **pout,
+                                int entropy, size_t min_len, size_t max_len)
+        {
+	*pout = OPENSSL_malloc(min_len);
+	if (!*pout)
+		return 0;
+	if (RAND_SSLeay()->bytes(*pout, min_len) <= 0)
+		{
+		OPENSSL_free(*pout);
+		*pout = NULL;
+		return 0;
+		}
+        return min_len;
+        }
+
+static void drbg_free_entropy(DRBG_CTX *ctx, unsigned char *out, size_t olen)
+	{
+	OPENSSL_cleanse(out, olen);
+	OPENSSL_free(out);
+	}
+
+/* RAND_add() and RAND_seed() pass through to OpenSSL PRNG so it is 
+ * correctly seeded by RAND_poll().
+ */
+
+static int drbg_rand_add(DRBG_CTX *ctx, const void *in, int inlen,
+				double entropy)
+	{
+	return RAND_SSLeay()->add(in, inlen, entropy);
+	}
+
+static int drbg_rand_seed(DRBG_CTX *ctx, const void *in, int inlen)
+	{
+	return RAND_SSLeay()->seed(in, inlen);
+	}
+
+int RAND_init_fips(void)
+	{
+	DRBG_CTX *dctx;
+	unsigned char pers[16] = {0,0,0};
+	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,
+					drbg_rand_seed, drbg_rand_add);
+        FIPS_drbg_instantiate(dctx, pers, sizeof(pers));
+        FIPS_rand_set_method(FIPS_drbg_method());
+	return 1;
+	}
+
+#endif