crypto: drbg - remove configuration of fixed values

SP800-90A mandates several hard-coded values. The old drbg_cores allows
the setting of these values per DRBG implementation. However, due to the
hard requirement of SP800-90A, these values are now returned globally
for each DRBG.

The ability to set such values per DRBG is therefore removed.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 6 insertions, 13 deletions

diff --git a/include/crypto/drbg.h b/include/crypto/drbg.h
index 831d786976c5..3d8e73a1a1c7 100644
--- a/include/crypto/drbg.h
+++ b/include/crypto/drbg.h
@@ -82,15 +82,6 @@ typedef uint32_t drbg_flag_t;
 struct drbg_core {
         drbg_flag_t flags;      /* flags for the cipher */
         __u8 statelen;          /* maximum state length */
-        /*
-         * maximum length of personalization string or additional input
-         * string -- exponent for base 2
-         */
-        __u8 max_addtllen;
-        /* maximum bits per RNG request -- exponent for base 2*/
-        __u8 max_bits;
-        /* maximum number of requests -- exponent for base 2 */
-        __u8 max_req;
         __u8 blocklen_bytes;    /* block size of output in bytes */
         char cra_name[CRYPTO_MAX_ALG_NAME]; /* mapping to kernel crypto API */
          /* kernel crypto API backend cipher name */
@@ -156,18 +147,20 @@ static inline __u8 drbg_keylen(struct drbg_state *drbg)
 
 static inline size_t drbg_max_request_bytes(struct drbg_state *drbg)
 {
-        /* max_bits is in bits, but buflen is in bytes */
-        return (1 << (drbg->core->max_bits - 3));
+        /* SP800-90A requires the limit 2**19 bits, but we return bytes */
+        return (1 << 16);
 }
 
 static inline size_t drbg_max_addtl(struct drbg_state *drbg)
 {
-        return (1UL<<(drbg->core->max_addtllen));
+        /* SP800-90A requires 2**35 bytes additional info str / pers str */
+        return (1UL<<35);
 }
 
 static inline size_t drbg_max_requests(struct drbg_state *drbg)
 {
-        return (1UL<<(drbg->core->max_req));
+        /* SP800-90A requires 2**48 maximum requests before reseeding */
+        return (1UL<<48);
 }
 
 /*