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Diffstat (limited to 'crypto/ansi_cprng.c')
-rw-r--r--crypto/ansi_cprng.c149
1 files changed, 98 insertions, 51 deletions
diff --git a/crypto/ansi_cprng.c b/crypto/ansi_cprng.c
index 0fac8ffc2fb..666f1962a16 100644
--- a/crypto/ansi_cprng.c
+++ b/crypto/ansi_cprng.c
@@ -83,9 +83,9 @@ 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
+ * returns 0 if generation succeeded, <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;
}
@@ -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;
@@ -227,11 +230,11 @@ remainder:
*/
if (byte_count < DEFAULT_BLK_SZ) {
empty_rbuf:
- for (; ctx->rand_data_valid < DEFAULT_BLK_SZ;
- ctx->rand_data_valid++) {
+ while (ctx->rand_data_valid < DEFAULT_BLK_SZ) {
*ptr = ctx->rand_data[ctx->rand_data_valid];
ptr++;
byte_count--;
+ ctx->rand_data_valid++;
if (byte_count == 0)
goto done;
}
@@ -242,7 +245,7 @@ empty_rbuf:
*/
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;
@@ -262,7 +265,7 @@ empty_rbuf:
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;
@@ -278,10 +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;
@@ -302,34 +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)
@@ -337,8 +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)
@@ -351,7 +354,7 @@ 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);
}
/*
@@ -379,7 +382,45 @@ static int cprng_reset(struct crypto_rng *tfm, u8 *seed, unsigned int slen)
return 0;
}
-static struct crypto_alg rng_alg = {
+#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];
+ u8 *key = seed + DEFAULT_BLK_SZ;
+ int rc;
+
+ struct prng_context *prng = crypto_rng_ctx(tfm);
+
+ if (slen < DEFAULT_PRNG_KSZ + DEFAULT_BLK_SZ)
+ return -EINVAL;
+
+ /* fips strictly requires seed != key */
+ if (!memcmp(seed, key, DEFAULT_PRNG_KSZ))
+ return -EINVAL;
+
+ 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;
+}
+#endif
+
+static struct crypto_alg rng_algs[] = { {
.cra_name = "stdrng",
.cra_driver_name = "ansi_cprng",
.cra_priority = 100,
@@ -387,7 +428,6 @@ static struct crypto_alg rng_alg = {
.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 = {
@@ -397,29 +437,36 @@ static struct crypto_alg rng_alg = {
.seedsize = DEFAULT_PRNG_KSZ + 2*DEFAULT_BLK_SZ,
}
}
-};
-
+#ifdef CONFIG_CRYPTO_FIPS
+}, {
+ .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_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;
-
- if (fips_enabled)
- rng_alg.cra_priority += 200;
-
- ret = crypto_register_alg(&rng_alg);
-
- if (ret)
- goto out;
-out:
- return 0;
+ return crypto_register_algs(rng_algs, ARRAY_SIZE(rng_algs));
}
static void __exit prng_mod_fini(void)
{
- crypto_unregister_alg(&rng_alg);
- return;
+ crypto_unregister_algs(rng_algs, ARRAY_SIZE(rng_algs));
}
MODULE_LICENSE("GPL");
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-12-06 13:19:11 +0000