lkml.org 
[lkml]   [2007]   [Mar]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 1/5] AF_RXRPC: Add blkcipher accessors for using kernel data directly [try #2]
Date
Add blkcipher accessors for using kernel data directly without the use of
scatter lists.

Also add a CRYPTO_ALG_DMA algorithm capability flag to permit or deny the use
of DMA and hardware accelerators. A hardware accelerator may not be used to
access any arbitrary piece of kernel memory lest it not be in a DMA'able
region. Only software algorithms may do that.

If kernel data is going to be accessed directly, then CRYPTO_ALG_DMA must, for
instance, be passed in the mask of crypto_alloc_blkcipher(), but not the type.

Signed-Off-By: David Howells <dhowells@redhat.com>
---
crypto/blkcipher.c | 2 ++
crypto/pcbc.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/crypto.h | 53 ++++++++++++++++++++++++++++++++++++++++-
3 files changed, 116 insertions(+), 1 deletions(-)
diff --git a/crypto/blkcipher.c b/crypto/blkcipher.c
index b5befe8..4498b2d 100644
--- a/crypto/blkcipher.c
+++ b/crypto/blkcipher.c
@@ -376,6 +376,8 @@ static int crypto_init_blkcipher_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
crt->setkey = setkey;
crt->encrypt = alg->encrypt;
crt->decrypt = alg->decrypt;
+ crt->encrypt_kernel = alg->encrypt_kernel;
+ crt->decrypt_kernel = alg->decrypt_kernel;

addr = (unsigned long)crypto_tfm_ctx(tfm);
addr = ALIGN(addr, align);
diff --git a/crypto/pcbc.c b/crypto/pcbc.c
index 5174d7f..fa76111 100644
--- a/crypto/pcbc.c
+++ b/crypto/pcbc.c
@@ -126,6 +126,36 @@ static int crypto_pcbc_encrypt(struct blkcipher_desc *desc,
return err;
}

+static int crypto_pcbc_encrypt_kernel(struct blkcipher_desc *desc,
+ u8 *dst, const u8 *src,
+ unsigned int nbytes)
+{
+ struct blkcipher_walk walk;
+ struct crypto_blkcipher *tfm = desc->tfm;
+ struct crypto_pcbc_ctx *ctx = crypto_blkcipher_ctx(tfm);
+ struct crypto_cipher *child = ctx->child;
+ void (*xor)(u8 *, const u8 *, unsigned int bs) = ctx->xor;
+
+ BUG_ON(crypto_tfm_alg_capabilities(crypto_cipher_tfm(child)) &
+ CRYPTO_ALG_DMA);
+
+ if (nbytes == 0)
+ return 0;
+
+ memset(&walk, 0, sizeof(walk));
+ walk.src.virt.addr = (u8 *) src;
+ walk.dst.virt.addr = (u8 *) dst;
+ walk.nbytes = nbytes;
+ walk.total = nbytes;
+ walk.iv = desc->info;
+
+ if (walk.src.virt.addr == walk.dst.virt.addr)
+ nbytes = crypto_pcbc_encrypt_inplace(desc, &walk, child, xor);
+ else
+ nbytes = crypto_pcbc_encrypt_segment(desc, &walk, child, xor);
+ return 0;
+}
+
static int crypto_pcbc_decrypt_segment(struct blkcipher_desc *desc,
struct blkcipher_walk *walk,
struct crypto_cipher *tfm,
@@ -211,6 +241,36 @@ static int crypto_pcbc_decrypt(struct blkcipher_desc *desc,
return err;
}

+static int crypto_pcbc_decrypt_kernel(struct blkcipher_desc *desc,
+ u8 *dst, const u8 *src,
+ unsigned int nbytes)
+{
+ struct blkcipher_walk walk;
+ struct crypto_blkcipher *tfm = desc->tfm;
+ struct crypto_pcbc_ctx *ctx = crypto_blkcipher_ctx(tfm);
+ struct crypto_cipher *child = ctx->child;
+ void (*xor)(u8 *, const u8 *, unsigned int bs) = ctx->xor;
+
+ BUG_ON(crypto_tfm_alg_capabilities(crypto_cipher_tfm(child)) &
+ CRYPTO_ALG_DMA);
+
+ if (nbytes == 0)
+ return 0;
+
+ memset(&walk, 0, sizeof(walk));
+ walk.src.virt.addr = (u8 *) src;
+ walk.dst.virt.addr = (u8 *) dst;
+ walk.nbytes = nbytes;
+ walk.total = nbytes;
+ walk.iv = desc->info;
+
+ if (walk.src.virt.addr == walk.dst.virt.addr)
+ nbytes = crypto_pcbc_decrypt_inplace(desc, &walk, child, xor);
+ else
+ nbytes = crypto_pcbc_decrypt_segment(desc, &walk, child, xor);
+ return 0;
+}
+
static void xor_byte(u8 *a, const u8 *b, unsigned int bs)
{
do {
@@ -313,6 +373,8 @@ static struct crypto_instance *crypto_pcbc_alloc(void *param, unsigned int len)
inst->alg.cra_blkcipher.setkey = crypto_pcbc_setkey;
inst->alg.cra_blkcipher.encrypt = crypto_pcbc_encrypt;
inst->alg.cra_blkcipher.decrypt = crypto_pcbc_decrypt;
+ inst->alg.cra_blkcipher.encrypt_kernel = crypto_pcbc_encrypt_kernel;
+ inst->alg.cra_blkcipher.decrypt_kernel = crypto_pcbc_decrypt_kernel;

out_put_alg:
crypto_mod_put(alg);
diff --git a/include/linux/crypto.h b/include/linux/crypto.h
index 779aa78..ce092fe 100644
--- a/include/linux/crypto.h
+++ b/include/linux/crypto.h
@@ -40,7 +40,10 @@
#define CRYPTO_ALG_LARVAL 0x00000010
#define CRYPTO_ALG_DEAD 0x00000020
#define CRYPTO_ALG_DYING 0x00000040
-#define CRYPTO_ALG_ASYNC 0x00000080
+
+#define CRYPTO_ALG_CAP_MASK 0x00000180 /* capabilities mask */
+#define CRYPTO_ALG_ASYNC 0x00000080 /* capable of async operation */
+#define CRYPTO_ALG_DMA 0x00000100 /* capable of using of DMA */

/*
* Set this bit if and only if the algorithm requires another algorithm of
@@ -125,6 +128,10 @@ struct blkcipher_alg {
int (*decrypt)(struct blkcipher_desc *desc,
struct scatterlist *dst, struct scatterlist *src,
unsigned int nbytes);
+ int (*encrypt_kernel)(struct blkcipher_desc *desc, u8 *dst,
+ const u8 *src, unsigned int nbytes);
+ int (*decrypt_kernel)(struct blkcipher_desc *desc, u8 *dst,
+ const u8 *src, unsigned int nbytes);

unsigned int min_keysize;
unsigned int max_keysize;
@@ -240,6 +247,10 @@ struct blkcipher_tfm {
struct scatterlist *src, unsigned int nbytes);
int (*decrypt)(struct blkcipher_desc *desc, struct scatterlist *dst,
struct scatterlist *src, unsigned int nbytes);
+ int (*encrypt_kernel)(struct blkcipher_desc *desc, u8 *dst,
+ const u8 *src, unsigned int nbytes);
+ int (*decrypt_kernel)(struct blkcipher_desc *desc, u8 *dst,
+ const u8 *src, unsigned int nbytes);
};

struct cipher_tfm {
@@ -372,6 +383,11 @@ static inline u32 crypto_tfm_alg_type(struct crypto_tfm *tfm)
return tfm->__crt_alg->cra_flags & CRYPTO_ALG_TYPE_MASK;
}

+static inline u32 crypto_tfm_alg_capabilities(struct crypto_tfm *tfm)
+{
+ return tfm->__crt_alg->cra_flags & CRYPTO_ALG_CAP_MASK;
+}
+
static inline unsigned int crypto_tfm_alg_blocksize(struct crypto_tfm *tfm)
{
return tfm->__crt_alg->cra_blocksize;
@@ -529,6 +545,23 @@ static inline int crypto_blkcipher_encrypt_iv(struct blkcipher_desc *desc,
return crypto_blkcipher_crt(desc->tfm)->encrypt(desc, dst, src, nbytes);
}

+static inline void crypto_blkcipher_encrypt_kernel(struct blkcipher_desc *desc,
+ u8 *dst, const u8 *src,
+ unsigned int nbytes)
+{
+ desc->info = crypto_blkcipher_crt(desc->tfm)->iv;
+ crypto_blkcipher_crt(desc->tfm)->encrypt_kernel(desc, dst, src,
+ nbytes);
+}
+
+static inline void crypto_blkcipher_encrypt_kernel_iv(struct blkcipher_desc *desc,
+ u8 *dst, const u8 *src,
+ unsigned int nbytes)
+{
+ crypto_blkcipher_crt(desc->tfm)->encrypt_kernel(desc, dst, src,
+ nbytes);
+}
+
static inline int crypto_blkcipher_decrypt(struct blkcipher_desc *desc,
struct scatterlist *dst,
struct scatterlist *src,
@@ -546,6 +579,24 @@ static inline int crypto_blkcipher_decrypt_iv(struct blkcipher_desc *desc,
return crypto_blkcipher_crt(desc->tfm)->decrypt(desc, dst, src, nbytes);
}

+static inline void crypto_blkcipher_decrypt_kernel(struct blkcipher_desc *desc,
+ u8 *dst, const u8 *src,
+ unsigned int nbytes)
+{
+ desc->info = crypto_blkcipher_crt(desc->tfm)->iv;
+ crypto_blkcipher_crt(desc->tfm)->decrypt_kernel(desc, dst, src,
+ nbytes);
+}
+
+static inline
+void crypto_blkcipher_decrypt_kernel_iv(struct blkcipher_desc *desc,
+ u8 *dst, const u8 *src,
+ unsigned int nbytes)
+{
+ crypto_blkcipher_crt(desc->tfm)->decrypt_kernel(desc, dst, src,
+ nbytes);
+}
+
static inline void crypto_blkcipher_set_iv(struct crypto_blkcipher *tfm,
const u8 *src, unsigned int len)
{
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-03-16 13:53    [W:0.104 / U:0.176 seconds]
©2003-2014 Jasper Spaans. Advertise on this site