crypto: drbg - Remove support for HASH_DRBG

Remove the support for HASH_DRBG.  It's likely unused code, seeing as
HMAC_DRBG is always enabled and prioritized over it unless
NETLINK_CRYPTO is used to change the algorithm priorities.

There's also no compelling reason to support more than one of
[HMAC_DRBG, HASH_DRBG, CTR_DRBG].  By definition, callers cannot tell
any difference in their outputs.  And all are FIPS-certifiable, which is
the only point of the kernel's NIST DRBGs anyway.

Switching to HASH_DRBG doesn't seem all that compelling, either.  For
one, it's more complex than HMAC_DRBG.

Thus, let's just drop HASH_DRBG support and focus on HMAC_DRBG.

Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

2 files changed, 2 insertions, 2 deletions

diff --git a/Documentation/crypto/api-samples.rst b/Documentation/crypto/api-samples.rst
index e923f17bc2bd..388bb7d7a460 100644
--- a/Documentation/crypto/api-samples.rst
+++ b/Documentation/crypto/api-samples.rst
@@ -159,7 +159,7 @@ Code Example For Random Number Generator Usage
     static int get_random_numbers(u8 *buf, unsigned int len)
     {
         struct crypto_rng *rng = NULL;
-        char *drbg = "drbg_nopr_sha256"; /* Hash DRBG with SHA-256, no PR */
+        char *drbg = "stdrng";
         int ret;
 
         if (!buf || !len) {
diff --git a/Documentation/crypto/userspace-if.rst b/Documentation/crypto/userspace-if.rst
index 021759198fe7..a3b13ff83cb3 100644
--- a/Documentation/crypto/userspace-if.rst
+++ b/Documentation/crypto/userspace-if.rst
@@ -297,7 +297,7 @@ follows:
     struct sockaddr_alg sa = {
         .salg_family = AF_ALG,
         .salg_type = "rng", /* this selects the random number generator */
-        .salg_name = "drbg_nopr_sha256" /* this is the RNG name */
+        .salg_name = "stdrng" /* this is the RNG name */
     };