It's more legible, and the code is 16 bytes smaller (i386).
Signed-off-by: George Spelvin <linux@xxxxxxxxxxx>
---
crypto/ansi_cprng.c | 91 +++++++++++++++++++++--------------------------------
1 file changed, 35 insertions(+), 56 deletions(-)
diff --git a/crypto/ansi_cprng.c b/crypto/ansi_cprng.c
index b63b5094..ce315bf7 100644
--- a/crypto/ansi_cprng.c
+++ b/crypto/ansi_cprng.c
@@ -100,69 +100,48 @@ static int _get_more_prng_bytes(struct prng_context *ctx, int cont_test)
hexdump("Input V: ", ctx->V, DEFAULT_BLK_SZ);
/*
- * This algorithm is a 3 stage state machine
+ * Start by encrypting the counter value
+ * This gives us an intermediate value I
*/
- for (i = 0; i < 3; i++) {
+ memcpy(tmp, ctx->DT, DEFAULT_BLK_SZ);
+ output = ctx->I;
+ hexdump("tmp stage 0: ", tmp, DEFAULT_BLK_SZ);
+ crypto_cipher_encrypt_one(ctx->tfm, output, tmp);
- switch (i) {
- case 0:
- /*
- * Start by encrypting the counter value
- * This gives us an intermediate value I
- */
- memcpy(tmp, ctx->DT, DEFAULT_BLK_SZ);
- output = ctx->I;
- hexdump("tmp stage 0: ", tmp, DEFAULT_BLK_SZ);
- break;
- case 1:
-
- /*
- * Next xor I with our secret vector V
- * encrypt that result to obtain our
- * pseudo random data which we output
- */
- xor_vectors(ctx->I, ctx->V, tmp, DEFAULT_BLK_SZ);
- hexdump("tmp stage 1: ", tmp, DEFAULT_BLK_SZ);
- output = ctx->rand_data;
- break;
- case 2:
- /*
- * First check that we didn't produce the same
- * random data that we did last time around through this
- */
- 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;
- }
- memcpy(ctx->last_rand_data, ctx->rand_data,
- DEFAULT_BLK_SZ);
+ /*
+ * Next xor I with our secret vector V
+ * encrypt that result to obtain our
+ * pseudo random data which we output
+ */
+ xor_vectors(ctx->I, ctx->V, tmp, DEFAULT_BLK_SZ);
+ hexdump("tmp stage 1: ", tmp, DEFAULT_BLK_SZ);
+ output = ctx->rand_data;
+ crypto_cipher_encrypt_one(ctx->tfm, output, tmp);
- /*
- * Lastly xor the random data with I
- * and encrypt that to obtain a new secret vector V
- */
- xor_vectors(ctx->rand_data, ctx->I, tmp,
- DEFAULT_BLK_SZ);
- output = ctx->V;
- hexdump("tmp stage 2: ", tmp, DEFAULT_BLK_SZ);
- break;
+ /*
+ * First check that we didn't produce the same
+ * random data that we did last time around through this
+ */
+ 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);
- /* do the encryption */
- crypto_cipher_encrypt_one(ctx->tfm, output, tmp);
-
+ ctx->flags |= PRNG_NEED_RESET;
+ return -EINVAL;
}
+ memcpy(ctx->last_rand_data, ctx->rand_data, DEFAULT_BLK_SZ);
+
+ /*
+ * Lastly xor the random data with I
+ * and encrypt that to obtain a new secret vector V
+ */
+ xor_vectors(ctx->rand_data, ctx->I, tmp, DEFAULT_BLK_SZ);
+ output = ctx->V;
+ hexdump("tmp stage 2: ", tmp, DEFAULT_BLK_SZ);
+ crypto_cipher_encrypt_one(ctx->tfm, output, tmp);
/*
* Now update our DT value
--
2.1.3
--
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