[PATCH v2 08/25] crypto: ansi_cprng - Don't call reset_prng_context from cprng_init

[George Spelvin]

The PRNG_NEEDS_RESET flag ensures that it will be called, so
reset_prng_context() no longer needs to support NULL key and V pointers.

Signed-off-by: George Spelvin <li...@horizon.com>
---
 crypto/ansi_cprng.c | 47 ++++++++++++++---------------------------------
 1 file changed, 14 insertions(+), 33 deletions(-)

diff --git a/crypto/ansi_cprng.c b/crypto/ansi_cprng.c
index 022662d7..62b8f958 100644
--- a/crypto/ansi_cprng.c
+++ b/crypto/ansi_cprng.c
@@ -23,10 +23,8 @@
 
 #include "internal.h"
 
-#define DEFAULT_PRNG_KEY "0123456789abcdef"
 #define DEFAULT_PRNG_KSZ 16
 #define DEFAULT_BLK_SZ 16
-#define DEFAULT_V_SEED "zaybxcwdveuftgsh"
 
 /*
  * Flags for the prng_context flags field
@@ -250,41 +248,28 @@ static int reset_prng_context(struct prng_context *ctx,
                              unsigned char *V, unsigned char *DT)
 {
        int ret;
-       unsigned char *prng_key;
 
        spin_lock_bh(&ctx->prng_lock);
        ctx->flags |= PRNG_NEED_RESET;
-
-       prng_key = (key != NULL) ? key : (unsigned char *)DEFAULT_PRNG_KEY;
-
-       if (!key)
-               klen = DEFAULT_PRNG_KSZ;
-
-       if (V)
-               memcpy(ctx->V, V, DEFAULT_BLK_SZ);
-       else
-               memcpy(ctx->V, DEFAULT_V_SEED, DEFAULT_BLK_SZ);
-
-       if (DT)
-               memcpy(ctx->DT, DT, DEFAULT_BLK_SZ);
-       else
-               memset(ctx->DT, 0, DEFAULT_BLK_SZ);
-
-       memset(ctx->rand_data, 0, DEFAULT_BLK_SZ);
-
        ctx->rand_data_valid = DEFAULT_BLK_SZ;
 
-       ret = crypto_cipher_setkey(ctx->tfm, prng_key, klen);
+       memset(ctx->rand_data, 0, DEFAULT_BLK_SZ);
+
+       if (!DT)
+               DT = ctx->rand_data;    /* Use all-zeros if NULL */
+
+       memcpy(ctx->DT, DT, DEFAULT_BLK_SZ);
+       memcpy(ctx->V, V, DEFAULT_BLK_SZ);
+
+       ret = crypto_cipher_setkey(ctx->tfm, key, klen);
        if (ret) {
                dbgprint(KERN_CRIT "PRNG: setkey() failed flags=%x\n",
                        crypto_cipher_get_flags(ctx->tfm));
-               goto out;
+       } else {
+               ctx->flags &= ~PRNG_NEED_RESET;
        }
-
-       ret = 0;
-       ctx->flags &= ~PRNG_NEED_RESET;
-out:
        spin_unlock_bh(&ctx->prng_lock);
+
        return ret;
 }
 
@@ -300,13 +285,9 @@ static int cprng_init(struct crypto_tfm *tfm)
                return PTR_ERR(ctx->tfm);
        }
 
-       if (reset_prng_context(ctx, NULL, DEFAULT_PRNG_KSZ, NULL, NULL) < 0)
-               return -EINVAL;
-
        /*
-        * after allocation, we should always force the user to reset
-        * so they don't inadvertently use the insecure default values
-        * without specifying them intentially
+        * After allocation, we always force the user to reset, which
+        * completes initialization of the context.
         */
        ctx->flags |= PRNG_NEED_RESET;
        return 0;
-- 
2.1.3

--
To unsubscribe from this list: send the line "unsubscribe linux-crypto" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html