2008-07-17 18:30:25

by Neil Horman

Subject: [PATCH] crypto: Cleaning some more minor nits in prng

Clean up a few more minor nits in the prng

Now that we use a plain cipher instead of a blkcipher, we don't need an iv
anymore, so remove that parameter from the reset_prng_context function. Make
it instead with a legngth parameter, so that we can treat the key as a blob,
rather than a string. Also change the get_prng_bytes function to make nbytes
a size_t, so we don't have to worry about signed math there

Signed-off-by: Neil Horman <[email protected]>

prng.c | 11 +++++++----
prng.h | 4 ++--
2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/crypto/prng.c b/crypto/prng.c
index 9e2d277..0b1831e 100644
--- a/crypto/prng.c
+++ b/crypto/prng.c
@@ -189,7 +189,7 @@ static int _get_more_prng_bytes(struct prng_context *ctx)
}

/* Our exported functions */
-int get_prng_bytes(char *buf, int nbytes, struct prng_context *ctx)
+int get_prng_bytes(char *buf, size_t nbytes, struct prng_context *ctx)
{
unsigned long flags;
unsigned char *ptr = buf;
@@ -284,7 +284,7 @@ struct prng_context *alloc_prng_context(void)

spin_lock_init(&ctx->prng_lock);

- if (reset_prng_context(ctx, NULL, NULL, NULL, NULL)) {
+ if (reset_prng_context(ctx, NULL, DEFAULT_PRNG_KSZ, NULL, NULL)) {
kfree(ctx);
ctx = NULL;
}
@@ -302,7 +302,7 @@ void free_prng_context(struct prng_context *ctx)
EXPORT_SYMBOL_GPL(free_prng_context);

int reset_prng_context(struct prng_context *ctx,
- unsigned char *key, unsigned char *iv,
+ unsigned char *key, size_t klen,
unsigned char *V, unsigned char *DT)
{
int ret;
@@ -313,6 +313,9 @@ int reset_prng_context(struct prng_context *ctx,

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
@@ -339,7 +342,7 @@ int reset_prng_context(struct prng_context *ctx,

ctx->rand_data_valid = DEFAULT_BLK_SZ;

- ret = crypto_cipher_setkey(ctx->tfm, prng_key, strlen(prng_key));
+ 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));
diff --git a/crypto/prng.h b/crypto/prng.h
index 1ac9be5..a6ad203 100644
--- a/crypto/prng.h
+++ b/crypto/prng.h
@@ -15,10 +15,10 @@
#define _PRNG_H_
struct prng_context;

-int get_prng_bytes(char *buf, int nbytes, struct prng_context *ctx);
+int get_prng_bytes(char *buf, size_t nbytes, struct prng_context *ctx);
struct prng_context *alloc_prng_context(void);
int reset_prng_context(struct prng_context *ctx,
- unsigned char *key, unsigned char *iv,
+ unsigned char *key, size_t klen,
unsigned char *V,
unsigned char *DT);
void free_prng_context(struct prng_context *ctx);
--
/***************************************************
*Neil Horman
*[email protected]
*gpg keyid: 1024D / 0x92A74FA1
*http://pgp.mit.edu
***************************************************/

2008-07-17 18:45:03

by Joe Perches

Subject: Re: [PATCH] crypto: Cleaning some more minor nits in prng

On Thu, 2008-07-17 at 14:30 -0400, Neil Horman wrote:
> diff --git a/crypto/prng.c b/crypto/prng.c
> index 9e2d277..0b1831e 100644
> {
> int ret;
> @@ -313,6 +313,9 @@ int reset_prng_context(struct prng_context *ctx,
>
> 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

Perhaps more readable as:

if (key)
prng_key = key;
else {
prng_key = DEFAULT_PRNG_KEY;
klen = DEFAULT_PRNG_KSZ;
}