From: Christophe Saout <christophe@saout.de>
This patch fixes the bug where in-place encryption was not detected when
the same highmem pages is mapped twice to different virtual addresses.
This adds a parameter to xxx_process to indicate whether this is an
in-place encryption and moves the responsability to the caller using a
helper function scatterwalk.h.
---
25-akpm/crypto/cipher.c | 17 +++++++++--------
25-akpm/crypto/scatterwalk.h | 8 ++++++++
2 files changed, 17 insertions(+), 8 deletions(-)
diff -puN crypto/cipher.c~in-place-encryption-fix crypto/cipher.c
--- 25/crypto/cipher.c~in-place-encryption-fix Wed Feb 25 15:11:58 2004
+++ 25-akpm/crypto/cipher.c Wed Feb 25 15:11:58 2004
@@ -22,7 +22,7 @@
typedef void (cryptfn_t)(void *, u8 *, const u8 *);
typedef void (procfn_t)(struct crypto_tfm *, u8 *,
- u8*, cryptfn_t, int enc, void *);
+ u8*, cryptfn_t, int enc, void *, int);
static inline void xor_64(u8 *a, const u8 *b)
{
@@ -78,7 +78,9 @@ static int crypt(struct crypto_tfm *tfm,
scatterwalk_copychunks(src_p, &walk_in, bsize, 0);
- prfn(tfm, dst_p, src_p, crfn, enc, info);
+ prfn(tfm, dst_p, src_p, crfn, enc, info,
+ scatterwalk_samebuf(&walk_in, &walk_out,
+ src_p, dst_p));
scatterwalk_done(&walk_in, 0, nbytes);
@@ -92,8 +94,8 @@ static int crypt(struct crypto_tfm *tfm,
}
}
-static void cbc_process(struct crypto_tfm *tfm,
- u8 *dst, u8 *src, cryptfn_t fn, int enc, void *info)
+static void cbc_process(struct crypto_tfm *tfm, u8 *dst, u8 *src,
+ cryptfn_t fn, int enc, void *info, int in_place)
{
u8 *iv = info;
@@ -106,9 +108,8 @@ static void cbc_process(struct crypto_tf
fn(crypto_tfm_ctx(tfm), dst, iv);
memcpy(iv, dst, crypto_tfm_alg_blocksize(tfm));
} else {
- const int need_stack = (src == dst);
- u8 stack[need_stack ? crypto_tfm_alg_blocksize(tfm) : 0];
- u8 *buf = need_stack ? stack : dst;
+ u8 stack[in_place ? crypto_tfm_alg_blocksize(tfm) : 0];
+ u8 *buf = in_place ? stack : dst;
fn(crypto_tfm_ctx(tfm), buf, src);
tfm->crt_u.cipher.cit_xor_block(buf, iv);
@@ -119,7 +120,7 @@ static void cbc_process(struct crypto_tf
}
static void ecb_process(struct crypto_tfm *tfm, u8 *dst, u8 *src,
- cryptfn_t fn, int enc, void *info)
+ cryptfn_t fn, int enc, void *info, int in_place)
{
fn(crypto_tfm_ctx(tfm), dst, src);
}
diff -puN crypto/scatterwalk.h~in-place-encryption-fix crypto/scatterwalk.h
--- 25/crypto/scatterwalk.h~in-place-encryption-fix Wed Feb 25 15:11:58 2004
+++ 25-akpm/crypto/scatterwalk.h Wed Feb 25 15:11:58 2004
@@ -33,6 +33,14 @@ static inline struct scatterlist *sg_nex
return sg + 1;
}
+static inline int scatterwalk_samebuf(struct scatter_walk *walk_in,
+ struct scatter_walk *walk_out,
+ void *src_p, void *dst_p)
+{
+ return walk_in->page == walk_out->page &&
+ walk_in->data == src_p && walk_out->data == dst_p;
+}
+
void *scatterwalk_whichbuf(struct scatter_walk *walk, unsigned int nbytes, void *scratch);
void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg);
int scatterwalk_copychunks(void *buf, struct scatter_walk *walk, size_t nbytes, int out);
_