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-rw-r--r--crypto/cipher.c246
1 files changed, 156 insertions, 90 deletions
diff --git a/crypto/cipher.c b/crypto/cipher.c
index 69264497b48c..c4243345b154 100644
--- a/crypto/cipher.c
+++ b/crypto/cipher.c
@@ -4,6 +4,7 @@
* Cipher operations.
*
* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
+ * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
@@ -22,9 +23,13 @@
#include "internal.h"
#include "scatterwalk.h"
-typedef void (cryptfn_t)(void *, u8 *, const u8 *);
-typedef void (procfn_t)(struct crypto_tfm *, u8 *,
- u8*, cryptfn_t, void *);
+struct cipher_desc {
+ struct crypto_tfm *tfm;
+ void (*crfn)(void *ctx, u8 *dst, const u8 *src);
+ unsigned int (*prfn)(const struct cipher_desc *desc, u8 *dst,
+ const u8 *src, unsigned int nbytes);
+ void *info;
+};
static inline void xor_64(u8 *a, const u8 *b)
{
@@ -39,63 +44,57 @@ static inline void xor_128(u8 *a, const u8 *b)
((u32 *)a)[2] ^= ((u32 *)b)[2];
((u32 *)a)[3] ^= ((u32 *)b)[3];
}
-
-static inline void *prepare_src(struct scatter_walk *walk, int bsize,
- void *tmp, int in_place)
+
+static unsigned int crypt_slow(const struct cipher_desc *desc,
+ struct scatter_walk *in,
+ struct scatter_walk *out, unsigned int bsize)
{
- void *src = walk->data;
- int n = bsize;
+ u8 src[bsize];
+ u8 dst[bsize];
+ unsigned int n;
- if (unlikely(scatterwalk_across_pages(walk, bsize))) {
- src = tmp;
- n = scatterwalk_copychunks(src, walk, bsize, 0);
- }
- scatterwalk_advance(walk, n);
- return src;
-}
+ n = scatterwalk_copychunks(src, in, bsize, 0);
+ scatterwalk_advance(in, n);
-static inline void *prepare_dst(struct scatter_walk *walk, int bsize,
- void *tmp, int in_place)
-{
- void *dst = walk->data;
+ desc->prfn(desc, dst, src, bsize);
- if (unlikely(scatterwalk_across_pages(walk, bsize)) || in_place)
- dst = tmp;
- return dst;
-}
+ n = scatterwalk_copychunks(dst, out, bsize, 1);
+ scatterwalk_advance(out, n);
-static inline void complete_src(struct scatter_walk *walk, int bsize,
- void *src, int in_place)
-{
+ return bsize;
}
-static inline void complete_dst(struct scatter_walk *walk, int bsize,
- void *dst, int in_place)
+static inline unsigned int crypt_fast(const struct cipher_desc *desc,
+ struct scatter_walk *in,
+ struct scatter_walk *out,
+ unsigned int nbytes)
{
- int n = bsize;
+ u8 *src, *dst;
+
+ src = in->data;
+ dst = scatterwalk_samebuf(in, out) ? src : out->data;
+
+ nbytes = desc->prfn(desc, dst, src, nbytes);
+
+ scatterwalk_advance(in, nbytes);
+ scatterwalk_advance(out, nbytes);
- if (unlikely(scatterwalk_across_pages(walk, bsize)))
- n = scatterwalk_copychunks(dst, walk, bsize, 1);
- else if (in_place)
- memcpy(walk->data, dst, bsize);
- scatterwalk_advance(walk, n);
+ return nbytes;
}
/*
* Generic encrypt/decrypt wrapper for ciphers, handles operations across
* multiple page boundaries by using temporary blocks. In user context,
- * the kernel is given a chance to schedule us once per block.
+ * the kernel is given a chance to schedule us once per page.
*/
-static int crypt(struct crypto_tfm *tfm,
+static int crypt(const struct cipher_desc *desc,
struct scatterlist *dst,
struct scatterlist *src,
- unsigned int nbytes, cryptfn_t crfn,
- procfn_t prfn, void *info)
+ unsigned int nbytes)
{
struct scatter_walk walk_in, walk_out;
+ struct crypto_tfm *tfm = desc->tfm;
const unsigned int bsize = crypto_tfm_alg_blocksize(tfm);
- u8 tmp_src[bsize];
- u8 tmp_dst[bsize];
if (!nbytes)
return 0;
@@ -109,29 +108,20 @@ static int crypt(struct crypto_tfm *tfm,
scatterwalk_start(&walk_out, dst);
for(;;) {
- u8 *src_p, *dst_p;
- int in_place;
+ unsigned int n;
scatterwalk_map(&walk_in, 0);
scatterwalk_map(&walk_out, 1);
- in_place = scatterwalk_samebuf(&walk_in, &walk_out);
+ n = scatterwalk_clamp(&walk_in, nbytes);
+ n = scatterwalk_clamp(&walk_out, n);
- do {
- src_p = prepare_src(&walk_in, bsize, tmp_src,
- in_place);
- dst_p = prepare_dst(&walk_out, bsize, tmp_dst,
- in_place);
+ if (likely(n >= bsize))
+ n = crypt_fast(desc, &walk_in, &walk_out, n);
+ else
+ n = crypt_slow(desc, &walk_in, &walk_out, bsize);
- prfn(tfm, dst_p, src_p, crfn, info);
-
- complete_src(&walk_in, bsize, src_p, in_place);
- complete_dst(&walk_out, bsize, dst_p, in_place);
-
- nbytes -= bsize;
- } while (nbytes &&
- !scatterwalk_across_pages(&walk_in, bsize) &&
- !scatterwalk_across_pages(&walk_out, bsize));
+ nbytes -= n;
scatterwalk_done(&walk_in, 0, nbytes);
scatterwalk_done(&walk_out, 1, nbytes);
@@ -143,30 +133,78 @@ static int crypt(struct crypto_tfm *tfm,
}
}
-static void cbc_process_encrypt(struct crypto_tfm *tfm, u8 *dst, u8 *src,
- cryptfn_t fn, void *info)
+static unsigned int cbc_process_encrypt(const struct cipher_desc *desc,
+ u8 *dst, const u8 *src,
+ unsigned int nbytes)
{
- u8 *iv = info;
+ struct crypto_tfm *tfm = desc->tfm;
+ void (*xor)(u8 *, const u8 *) = tfm->crt_u.cipher.cit_xor_block;
+ int bsize = crypto_tfm_alg_blocksize(tfm);
+
+ void (*fn)(void *, u8 *, const u8 *) = desc->crfn;
+ u8 *iv = desc->info;
+ unsigned int done = 0;
+
+ do {
+ xor(iv, src);
+ fn(crypto_tfm_ctx(tfm), dst, iv);
+ memcpy(iv, dst, bsize);
- tfm->crt_u.cipher.cit_xor_block(iv, src);
- fn(crypto_tfm_ctx(tfm), dst, iv);
- memcpy(iv, dst, crypto_tfm_alg_blocksize(tfm));
+ src += bsize;
+ dst += bsize;
+ } while ((done += bsize) < nbytes);
+
+ return done;
}
-static void cbc_process_decrypt(struct crypto_tfm *tfm, u8 *dst, u8 *src,
- cryptfn_t fn, void *info)
+static unsigned int cbc_process_decrypt(const struct cipher_desc *desc,
+ u8 *dst, const u8 *src,
+ unsigned int nbytes)
{
- u8 *iv = info;
+ struct crypto_tfm *tfm = desc->tfm;
+ void (*xor)(u8 *, const u8 *) = tfm->crt_u.cipher.cit_xor_block;
+ int bsize = crypto_tfm_alg_blocksize(tfm);
+
+ u8 stack[src == dst ? bsize : 0];
+ u8 *buf = stack;
+ u8 **dst_p = src == dst ? &buf : &dst;
+
+ void (*fn)(void *, u8 *, const u8 *) = desc->crfn;
+ u8 *iv = desc->info;
+ unsigned int done = 0;
+
+ do {
+ u8 *tmp_dst = *dst_p;
- fn(crypto_tfm_ctx(tfm), dst, src);
- tfm->crt_u.cipher.cit_xor_block(dst, iv);
- memcpy(iv, src, crypto_tfm_alg_blocksize(tfm));
+ fn(crypto_tfm_ctx(tfm), tmp_dst, src);
+ xor(tmp_dst, iv);
+ memcpy(iv, src, bsize);
+ if (tmp_dst != dst)
+ memcpy(dst, tmp_dst, bsize);
+
+ src += bsize;
+ dst += bsize;
+ } while ((done += bsize) < nbytes);
+
+ return done;
}
-static void ecb_process(struct crypto_tfm *tfm, u8 *dst, u8 *src,
- cryptfn_t fn, void *info)
+static unsigned int ecb_process(const struct cipher_desc *desc, u8 *dst,
+ const u8 *src, unsigned int nbytes)
{
- fn(crypto_tfm_ctx(tfm), dst, src);
+ struct crypto_tfm *tfm = desc->tfm;
+ int bsize = crypto_tfm_alg_blocksize(tfm);
+ void (*fn)(void *, u8 *, const u8 *) = desc->crfn;
+ unsigned int done = 0;
+
+ do {
+ fn(crypto_tfm_ctx(tfm), dst, src);
+
+ src += bsize;
+ dst += bsize;
+ } while ((done += bsize) < nbytes);
+
+ return done;
}
static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
@@ -185,9 +223,13 @@ static int ecb_encrypt(struct crypto_tfm *tfm,
struct scatterlist *dst,
struct scatterlist *src, unsigned int nbytes)
{
- return crypt(tfm, dst, src, nbytes,
- tfm->__crt_alg->cra_cipher.cia_encrypt,
- ecb_process, NULL);
+ struct cipher_desc desc;
+
+ desc.tfm = tfm;
+ desc.crfn = tfm->__crt_alg->cra_cipher.cia_encrypt;
+ desc.prfn = ecb_process;
+
+ return crypt(&desc, dst, src, nbytes);
}
static int ecb_decrypt(struct crypto_tfm *tfm,
@@ -195,9 +237,13 @@ static int ecb_decrypt(struct crypto_tfm *tfm,
struct scatterlist *src,
unsigned int nbytes)
{
- return crypt(tfm, dst, src, nbytes,
- tfm->__crt_alg->cra_cipher.cia_decrypt,
- ecb_process, NULL);
+ struct cipher_desc desc;
+
+ desc.tfm = tfm;
+ desc.crfn = tfm->__crt_alg->cra_cipher.cia_decrypt;
+ desc.prfn = ecb_process;
+
+ return crypt(&desc, dst, src, nbytes);
}
static int cbc_encrypt(struct crypto_tfm *tfm,
@@ -205,9 +251,14 @@ static int cbc_encrypt(struct crypto_tfm *tfm,
struct scatterlist *src,
unsigned int nbytes)
{
- return crypt(tfm, dst, src, nbytes,
- tfm->__crt_alg->cra_cipher.cia_encrypt,
- cbc_process_encrypt, tfm->crt_cipher.cit_iv);
+ struct cipher_desc desc;
+
+ desc.tfm = tfm;
+ desc.crfn = tfm->__crt_alg->cra_cipher.cia_encrypt;
+ desc.prfn = cbc_process_encrypt;
+ desc.info = tfm->crt_cipher.cit_iv;
+
+ return crypt(&desc, dst, src, nbytes);
}
static int cbc_encrypt_iv(struct crypto_tfm *tfm,
@@ -215,9 +266,14 @@ static int cbc_encrypt_iv(struct crypto_tfm *tfm,
struct scatterlist *src,
unsigned int nbytes, u8 *iv)
{
- return crypt(tfm, dst, src, nbytes,
- tfm->__crt_alg->cra_cipher.cia_encrypt,
- cbc_process_encrypt, iv);
+ struct cipher_desc desc;
+
+ desc.tfm = tfm;
+ desc.crfn = tfm->__crt_alg->cra_cipher.cia_encrypt;
+ desc.prfn = cbc_process_encrypt;
+ desc.info = iv;
+
+ return crypt(&desc, dst, src, nbytes);
}
static int cbc_decrypt(struct crypto_tfm *tfm,
@@ -225,9 +281,14 @@ static int cbc_decrypt(struct crypto_tfm *tfm,
struct scatterlist *src,
unsigned int nbytes)
{
- return crypt(tfm, dst, src, nbytes,
- tfm->__crt_alg->cra_cipher.cia_decrypt,
- cbc_process_decrypt, tfm->crt_cipher.cit_iv);
+ struct cipher_desc desc;
+
+ desc.tfm = tfm;
+ desc.crfn = tfm->__crt_alg->cra_cipher.cia_decrypt;
+ desc.prfn = cbc_process_decrypt;
+ desc.info = tfm->crt_cipher.cit_iv;
+
+ return crypt(&desc, dst, src, nbytes);
}
static int cbc_decrypt_iv(struct crypto_tfm *tfm,
@@ -235,9 +296,14 @@ static int cbc_decrypt_iv(struct crypto_tfm *tfm,
struct scatterlist *src,
unsigned int nbytes, u8 *iv)
{
- return crypt(tfm, dst, src, nbytes,
- tfm->__crt_alg->cra_cipher.cia_decrypt,
- cbc_process_decrypt, iv);
+ struct cipher_desc desc;
+
+ desc.tfm = tfm;
+ desc.crfn = tfm->__crt_alg->cra_cipher.cia_decrypt;
+ desc.prfn = cbc_process_decrypt;
+ desc.info = iv;
+
+ return crypt(&desc, dst, src, nbytes);
}
static int nocrypt(struct crypto_tfm *tfm,
generated by cgit v1.2.3 (git 2.0.4) at 2024-11-05 19:44:34 +0000