From: Nikos Mavrogiannopoulos <nmav@redhat.com>
Date: Wed, 22 Jan 2014 10:38:07 +0000 (+0100)
Subject: Updates in the DRBG-CTR-AES random number generator.
X-Git-Tag: gnutls_3_3_0pre0~304
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=af1fbb1aa68909a9e48220f102b8582354f8a3fd;p=thirdparty%2Fgnutls.git

Updates in the DRBG-CTR-AES random number generator.
---

diff --git a/lib/libgnutls.map b/lib/libgnutls.map
index 908587e381..da0118bb58 100644
--- a/lib/libgnutls.map
+++ b/lib/libgnutls.map
@@ -989,6 +989,10 @@ GNUTLS_PRIVATE {
     # Internal symbols needed by tests/pkcs12_s2k:
     _gnutls_pkcs12_string_to_key;
     _gnutls_bin2hex;
+    #for FIPS140-2 validation
+    drbg_aes_reseed;
+    drbg_aes_init;
+    drbg_aes_generate;
   local:
     *;
 };
diff --git a/lib/nettle/int/drbg-aes.c b/lib/nettle/int/drbg-aes.c
index fa2b6a1f27..a8ed9d629c 100644
--- a/lib/nettle/int/drbg-aes.c
+++ b/lib/nettle/int/drbg-aes.c
@@ -1,6 +1,6 @@
 /* drbg-aes.c */
 
-/* Copyright (C) 2013 Red Hat
+/* Copyright (C) 2013, 2014 Red Hat
  *
  * This file is part of GnuTLS.
  *  
@@ -47,7 +47,7 @@ drbg_aes_init(struct drbg_aes_ctx *ctx,
 /* Sets V and key based on pdata */
 static void
 drbg_aes_update(struct drbg_aes_ctx *ctx,
-		unsigned pdata_size, const uint8_t * pdata)
+		const uint8_t pdata[DRBG_AES_SEED_SIZE])
 {
 	unsigned len = 0;
 	uint8_t tmp[DRBG_AES_SEED_SIZE];
@@ -64,9 +64,7 @@ drbg_aes_update(struct drbg_aes_ctx *ctx,
 
 	aes_set_encrypt_key(&ctx->key, DRBG_AES_KEY_SIZE, tmp);
 
-	ctx->prev_block_present = 0;
-
-	memcpy(ctx->v, &tmp[AES_BLOCK_SIZE], AES_BLOCK_SIZE);
+	memcpy(ctx->v, &tmp[DRBG_AES_KEY_SIZE], AES_BLOCK_SIZE);
 
 	ctx->reseed_counter = 1;
 	ctx->seeded = 1;
@@ -93,21 +91,36 @@ drbg_aes_reseed(struct drbg_aes_ctx *ctx,
 
 	memxor(tmp, entropy, entropy_size);
 
-	drbg_aes_update(ctx, DRBG_AES_SEED_SIZE, tmp);
+	drbg_aes_update(ctx, tmp);
 
 	return 1;
 }
 
 /* we don't use additional input */
-int drbg_aes_random(struct drbg_aes_ctx *ctx, unsigned length, uint8_t * dst)
+int drbg_aes_generate(struct drbg_aes_ctx *ctx, unsigned length, uint8_t * dst,
+			unsigned add_size, const uint8_t *add)
 {
 	uint8_t tmp[AES_BLOCK_SIZE];
+	uint8_t seed[DRBG_AES_SEED_SIZE];
 	unsigned left;
 
 	if (ctx->seeded == 0)
 		return 0;
 
-	/* Throw the first block generated. FIPS 140-2 requirement 
+	if (add_size > 0) {
+		if (add_size > DRBG_AES_SEED_SIZE)
+			return 0;
+		memcpy(seed, add, add_size);
+		if (add_size != DRBG_AES_SEED_SIZE)
+			memset(&seed[add_size], 0, DRBG_AES_SEED_SIZE - add_size);
+
+		drbg_aes_update(ctx, seed);
+	} else {
+		memset(seed, 0, DRBG_AES_SEED_SIZE);
+	}
+
+	/* Throw the first block generated. FIPS 140-2 requirement (see 
+	 * the continuous random number generator test in 4.9.2)
 	 */
 	if (ctx->prev_block_present == 0) {
 		INCREMENT(sizeof(ctx->v), ctx->v);
@@ -147,6 +160,8 @@ int drbg_aes_random(struct drbg_aes_ctx *ctx, unsigned length, uint8_t * dst)
 		return 0;
 	ctx->reseed_counter++;
 
+	drbg_aes_update(ctx, seed);
+
 	return 1;
 }
 
diff --git a/lib/nettle/int/drbg-aes.h b/lib/nettle/int/drbg-aes.h
index 1c6ff5974c..0775d0a163 100644
--- a/lib/nettle/int/drbg-aes.h
+++ b/lib/nettle/int/drbg-aes.h
@@ -74,9 +74,11 @@ drbg_aes_reseed(struct drbg_aes_ctx *ctx,
 	unsigned entropy_size, const uint8_t *entropy, 
 	unsigned add_size, const uint8_t* add);
 
+#define drbg_aes_random(ctx, l, dst) drbg_aes_generate(ctx, l, dst, 0, NULL)
+
 int
-drbg_aes_random(struct drbg_aes_ctx *ctx, unsigned length,
-		uint8_t * dst);
+drbg_aes_generate(struct drbg_aes_ctx *ctx, unsigned length,
+		uint8_t * dst, unsigned add_size, const uint8_t* add);
 
 int drbg_aes_is_seeded(struct drbg_aes_ctx *ctx);