crypto: ansi_cprng - Add FIPS wrapper
Patch to add fips(ansi_cprng) alg, which is ansi_cprng plus a continuous test
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/ansi_cprng.c b/crypto/ansi_cprng.c
index 3aa6e38..027176a 100644
--- a/crypto/ansi_cprng.c
+++ b/crypto/ansi_cprng.c
@@ -85,7 +85,7 @@
* 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];
@@ -132,7 +132,7 @@
*/
if (!memcmp(ctx->rand_data, ctx->last_rand_data,
DEFAULT_BLK_SZ)) {
- if (fips_enabled) {
+ if (cont_test) {
panic("cprng %p Failed repetition check!\n",
ctx);
}
@@ -185,7 +185,8 @@
}
/* 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 char *ptr = buf;
unsigned int byte_count = (unsigned int)nbytes;
@@ -220,7 +221,7 @@
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;
@@ -247,7 +248,7 @@
*/
for (; byte_count >= DEFAULT_BLK_SZ; byte_count -= DEFAULT_BLK_SZ) {
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;
@@ -356,7 +357,15 @@
{
struct prng_context *prng = crypto_rng_ctx(tfm);
- return get_prng_bytes(rdata, dlen, prng);
+ return get_prng_bytes(rdata, dlen, prng, 0);
+}
+
+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);
}
/*
@@ -384,6 +393,26 @@
return 0;
}
+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 rng_alg = {
.cra_name = "stdrng",
.cra_driver_name = "ansi_cprng",
@@ -404,19 +433,51 @@
}
};
+#ifdef CONFIG_CRYPTO_FIPS
+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)
{
- if (fips_enabled)
- rng_alg.cra_priority += 200;
+ int rc = 0;
- return crypto_register_alg(&rng_alg);
+ rc = crypto_register_alg(&rng_alg);
+#ifdef CONFIG_CRYPTO_FIPS
+ if (rc)
+ goto out;
+
+ rc = crypto_register_alg(&fips_rng_alg);
+
+out:
+#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;
}