X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=crypto%2Fansi_cprng.c;h=2bc3321428494d727ca27064c73694f031443ea6;hb=0047e81dc366a0690b4765250c3a1d8caf3797c4;hp=72db0fd763cca01ed6ed17f35a494fa7744a0b47;hpb=17f0f4a47df9aea9ee26c939f8057c35e0be1847;p=safe%2Fjmp%2Flinux-2.6

diff --git a/crypto/ansi_cprng.c b/crypto/ansi_cprng.c
index 72db0fd..2bc3321 100644
--- a/crypto/ansi_cprng.c
+++ b/crypto/ansi_cprng.c
@@ -85,7 +85,7 @@ static void xor_vectors(unsigned char *in1, unsigned char *in2,
  * Returns DEFAULT_BLK_SZ bytes of random data per call
  * returns 0 if generation succeded, <0 if something went wrong
  */
-static int _get_more_prng_bytes(struct prng_context *ctx)
+static int _get_more_prng_bytes(struct prng_context *ctx, int cont_test)
 {
 	int i;
 	unsigned char tmp[DEFAULT_BLK_SZ];
@@ -132,9 +132,15 @@ static int _get_more_prng_bytes(struct prng_context *ctx)
 			 */
 			if (!memcmp(ctx->rand_data, ctx->last_rand_data,
 					DEFAULT_BLK_SZ)) {
+				if (cont_test) {
+					panic("cprng %p Failed repetition check!\n",
+						ctx);
+				}
+
 				printk(KERN_ERR
 					"ctx %p Failed repetition check!\n",
 					ctx);
+
 				ctx->flags |= PRNG_NEED_RESET;
 				return -EINVAL;
 			}
@@ -161,7 +167,7 @@ static int _get_more_prng_bytes(struct prng_context *ctx)
 	/*
 	 * Now update our DT value
 	 */
-	for (i = 0; i < DEFAULT_BLK_SZ; i++) {
+	for (i = DEFAULT_BLK_SZ - 1; i >= 0; i--) {
 		ctx->DT[i] += 1;
 		if (ctx->DT[i] != 0)
 			break;
@@ -179,18 +185,15 @@ static int _get_more_prng_bytes(struct prng_context *ctx)
 }
 
 /* Our exported functions */
-static int get_prng_bytes(char *buf, size_t nbytes, struct prng_context *ctx)
+static int get_prng_bytes(char *buf, size_t nbytes, struct prng_context *ctx,
+				int do_cont_test)
 {
-	unsigned long flags;
 	unsigned char *ptr = buf;
 	unsigned int byte_count = (unsigned int)nbytes;
 	int err;
 
 
-	if (nbytes < 0)
-		return -EINVAL;
-
-	spin_lock_irqsave(&ctx->prng_lock, flags);
+	spin_lock_bh(&ctx->prng_lock);
 
 	err = -EINVAL;
 	if (ctx->flags & PRNG_NEED_RESET)
@@ -215,7 +218,7 @@ static int get_prng_bytes(char *buf, size_t nbytes, struct prng_context *ctx)
 
 remainder:
 	if (ctx->rand_data_valid == DEFAULT_BLK_SZ) {
-		if (_get_more_prng_bytes(ctx) < 0) {
+		if (_get_more_prng_bytes(ctx, do_cont_test) < 0) {
 			memset(buf, 0, nbytes);
 			err = -EINVAL;
 			goto done;
@@ -223,9 +226,10 @@ remainder:
 	}
 
 	/*
-	 * Copy up to the next whole block size
+	 * Copy any data less than an entire block
 	 */
 	if (byte_count < DEFAULT_BLK_SZ) {
+empty_rbuf:
 		for (; ctx->rand_data_valid < DEFAULT_BLK_SZ;
 			ctx->rand_data_valid++) {
 			*ptr = ctx->rand_data[ctx->rand_data_valid];
@@ -240,24 +244,28 @@ remainder:
 	 * Now copy whole blocks
 	 */
 	for (; byte_count >= DEFAULT_BLK_SZ; byte_count -= DEFAULT_BLK_SZ) {
-		if (_get_more_prng_bytes(ctx) < 0) {
-			memset(buf, 0, nbytes);
-			err = -EINVAL;
-			goto done;
+		if (ctx->rand_data_valid == DEFAULT_BLK_SZ) {
+			if (_get_more_prng_bytes(ctx, do_cont_test) < 0) {
+				memset(buf, 0, nbytes);
+				err = -EINVAL;
+				goto done;
+			}
 		}
+		if (ctx->rand_data_valid > 0)
+			goto empty_rbuf;
 		memcpy(ptr, ctx->rand_data, DEFAULT_BLK_SZ);
 		ctx->rand_data_valid += DEFAULT_BLK_SZ;
 		ptr += DEFAULT_BLK_SZ;
 	}
 
 	/*
-	 * Now copy any extra partial data
+	 * Now go back and get any remaining partial block
 	 */
 	if (byte_count)
 		goto remainder;
 
 done:
-	spin_unlock_irqrestore(&ctx->prng_lock, flags);
+	spin_unlock_bh(&ctx->prng_lock);
 	dbgprint(KERN_CRIT "returning %d from get_prng_bytes in context %p\n",
 		err, ctx);
 	return err;
@@ -273,10 +281,9 @@ static int reset_prng_context(struct prng_context *ctx,
 			      unsigned char *V, unsigned char *DT)
 {
 	int ret;
-	int rc = -EINVAL;
 	unsigned char *prng_key;
 
-	spin_lock(&ctx->prng_lock);
+	spin_lock_bh(&ctx->prng_lock);
 	ctx->flags |= PRNG_NEED_RESET;
 
 	prng_key = (key != NULL) ? key : (unsigned char *)DEFAULT_PRNG_KEY;
@@ -297,34 +304,20 @@ static int reset_prng_context(struct prng_context *ctx,
 	memset(ctx->rand_data, 0, DEFAULT_BLK_SZ);
 	memset(ctx->last_rand_data, 0, DEFAULT_BLK_SZ);
 
-	if (ctx->tfm)
-		crypto_free_cipher(ctx->tfm);
-
-	ctx->tfm = crypto_alloc_cipher("aes", 0, 0);
-	if (IS_ERR(ctx->tfm)) {
-		dbgprint(KERN_CRIT "Failed to alloc tfm for context %p\n",
-			ctx);
-		ctx->tfm = NULL;
-		goto out;
-	}
-
 	ctx->rand_data_valid = DEFAULT_BLK_SZ;
 
 	ret = crypto_cipher_setkey(ctx->tfm, prng_key, klen);
 	if (ret) {
 		dbgprint(KERN_CRIT "PRNG: setkey() failed flags=%x\n",
 			crypto_cipher_get_flags(ctx->tfm));
-		crypto_free_cipher(ctx->tfm);
 		goto out;
 	}
 
-	rc = 0;
+	ret = 0;
 	ctx->flags &= ~PRNG_NEED_RESET;
 out:
-	spin_unlock(&ctx->prng_lock);
-
-	return rc;
-
+	spin_unlock_bh(&ctx->prng_lock);
+	return ret;
 }
 
 static int cprng_init(struct crypto_tfm *tfm)
@@ -332,8 +325,23 @@ static int cprng_init(struct crypto_tfm *tfm)
 	struct prng_context *ctx = crypto_tfm_ctx(tfm);
 
 	spin_lock_init(&ctx->prng_lock);
+	ctx->tfm = crypto_alloc_cipher("aes", 0, 0);
+	if (IS_ERR(ctx->tfm)) {
+		dbgprint(KERN_CRIT "Failed to alloc tfm for context %p\n",
+				ctx);
+		return PTR_ERR(ctx->tfm);
+	}
+
+	if (reset_prng_context(ctx, NULL, DEFAULT_PRNG_KSZ, NULL, NULL) < 0)
+		return -EINVAL;
 
-	return reset_prng_context(ctx, NULL, DEFAULT_PRNG_KSZ, NULL, NULL);
+	/*
+	 * after allocation, we should always force the user to reset
+	 * so they don't inadvertently use the insecure default values
+	 * without specifying them intentially
+	 */
+	ctx->flags |= PRNG_NEED_RESET;
+	return 0;
 }
 
 static void cprng_exit(struct crypto_tfm *tfm)
@@ -346,18 +354,28 @@ static int cprng_get_random(struct crypto_rng *tfm, u8 *rdata,
 {
 	struct prng_context *prng = crypto_rng_ctx(tfm);
 
-	return get_prng_bytes(rdata, dlen, prng);
+	return get_prng_bytes(rdata, dlen, prng, 0);
 }
 
+/*
+ *  This is the cprng_registered reset method the seed value is
+ *  interpreted as the tuple { V KEY DT}
+ *  V and KEY are required during reset, and DT is optional, detected
+ *  as being present by testing the length of the seed
+ */
 static int cprng_reset(struct crypto_rng *tfm, u8 *seed, unsigned int slen)
 {
 	struct prng_context *prng = crypto_rng_ctx(tfm);
-	u8 *key = seed + DEFAULT_PRNG_KSZ;
+	u8 *key = seed + DEFAULT_BLK_SZ;
+	u8 *dt = NULL;
 
 	if (slen < DEFAULT_PRNG_KSZ + DEFAULT_BLK_SZ)
 		return -EINVAL;
 
-	reset_prng_context(prng, key, DEFAULT_PRNG_KSZ, seed, NULL);
+	if (slen >= (2 * DEFAULT_BLK_SZ + DEFAULT_PRNG_KSZ))
+		dt = key + DEFAULT_PRNG_KSZ;
+
+	reset_prng_context(prng, key, DEFAULT_PRNG_KSZ, seed, dt);
 
 	if (prng->flags & PRNG_NEED_RESET)
 		return -EINVAL;
@@ -379,31 +397,84 @@ static struct crypto_alg rng_alg = {
 		.rng = {
 			.rng_make_random	= cprng_get_random,
 			.rng_reset		= cprng_reset,
-			.seedsize = DEFAULT_PRNG_KSZ + DEFAULT_BLK_SZ,
+			.seedsize = DEFAULT_PRNG_KSZ + 2*DEFAULT_BLK_SZ,
 		}
 	}
 };
 
+#ifdef CONFIG_CRYPTO_FIPS
+static int fips_cprng_get_random(struct crypto_rng *tfm, u8 *rdata,
+			    unsigned int dlen)
+{
+	struct prng_context *prng = crypto_rng_ctx(tfm);
+
+	return get_prng_bytes(rdata, dlen, prng, 1);
+}
+
+static int fips_cprng_reset(struct crypto_rng *tfm, u8 *seed, unsigned int slen)
+{
+	u8 rdata[DEFAULT_BLK_SZ];
+	int rc;
+
+	struct prng_context *prng = crypto_rng_ctx(tfm);
+
+	rc = cprng_reset(tfm, seed, slen);
+
+	if (!rc)
+		goto out;
+
+	/* this primes our continuity test */
+	rc = get_prng_bytes(rdata, DEFAULT_BLK_SZ, prng, 0);
+	prng->rand_data_valid = DEFAULT_BLK_SZ;
+
+out:
+	return rc;
+}
+
+static struct crypto_alg fips_rng_alg = {
+	.cra_name		= "fips(ansi_cprng)",
+	.cra_driver_name	= "fips_ansi_cprng",
+	.cra_priority		= 300,
+	.cra_flags		= CRYPTO_ALG_TYPE_RNG,
+	.cra_ctxsize		= sizeof(struct prng_context),
+	.cra_type		= &crypto_rng_type,
+	.cra_module		= THIS_MODULE,
+	.cra_list		= LIST_HEAD_INIT(rng_alg.cra_list),
+	.cra_init		= cprng_init,
+	.cra_exit		= cprng_exit,
+	.cra_u			= {
+		.rng = {
+			.rng_make_random	= fips_cprng_get_random,
+			.rng_reset		= fips_cprng_reset,
+			.seedsize = DEFAULT_PRNG_KSZ + 2*DEFAULT_BLK_SZ,
+		}
+	}
+};
+#endif
 
 /* Module initalization */
 static int __init prng_mod_init(void)
 {
-	int ret = 0;
+	int rc = 0;
 
-	if (fips_enabled)
-		rng_alg.cra_priority += 200;
+	rc = crypto_register_alg(&rng_alg);
+#ifdef CONFIG_CRYPTO_FIPS
+	if (rc)
+		goto out;
 
-	ret = crypto_register_alg(&rng_alg);
+	rc = crypto_register_alg(&fips_rng_alg);
 
-	if (ret)
-		goto out;
 out:
-	return 0;
+#endif
+	return rc;
 }
 
 static void __exit prng_mod_fini(void)
 {
 	crypto_unregister_alg(&rng_alg);
+#ifdef CONFIG_CRYPTO_FIPS
+	crypto_unregister_alg(&fips_rng_alg);
+#endif
 	return;
 }