We can simplify the blowfish-x86_64 glue code by using the preexisting
ECB/CBC helper macros. Additionally, this allows for easier reuse of asm
functions in later x86 implementations of blowfish.
This involves:
1 - Modifying blowfish_dec_blk_4way() to xor outputs when a flag is
passed.
2 - Renaming blowfish_dec_blk_4way() to __blowfish_dec_blk_4way().
3 - Creating two wrapper functions around __blowfish_dec_blk_4way() for
use in the ECB/CBC macros.
4 - Removing the custom ecb_encrypt() and cbc_encrypt() routines in
favor of macro-based routines.
Signed-off-by: Peter Lafreniere <peter@xxxxxxxx>
---
v1 -> v2:
- Fixed typo that caused an assembler failure
- Added note about performance to cover letter
arch/x86/crypto/blowfish-x86_64-asm_64.S | 30 +++-
arch/x86/crypto/blowfish_glue.c | 196 ++++-------------------
2 files changed, 58 insertions(+), 168 deletions(-)
diff --git a/arch/x86/crypto/blowfish-x86_64-asm_64.S b/arch/x86/crypto/blowfish-x86_64-asm_64.S
index 4c5d4bc28ac4..767a209ca989 100644
--- a/arch/x86/crypto/blowfish-x86_64-asm_64.S
+++ b/arch/x86/crypto/blowfish-x86_64-asm_64.S
@@ -260,6 +260,19 @@ SYM_FUNC_END(blowfish_dec_blk)
bswapq RX3; \
movq RX3, 24(RIO);
+#define xor_block4() \
+ movq (RIO), RT0; \
+ bswapq RT0; \
+ xorq RT0, RX1; \
+ \
+ movq 8(RIO), RT2; \
+ bswapq RT2; \
+ xorq RT2, RX2; \
+ \
+ movq 16(RIO), RT3; \
+ bswapq RT3; \
+ xorq RT3, RX3;
+
SYM_TYPED_FUNC_START(blowfish_enc_blk_4way)
/* input:
* %rdi: ctx
@@ -295,17 +308,20 @@ SYM_TYPED_FUNC_START(blowfish_enc_blk_4way)
RET;
SYM_FUNC_END(blowfish_enc_blk_4way)
-SYM_TYPED_FUNC_START(blowfish_dec_blk_4way)
+SYM_TYPED_FUNC_START(__blowfish_dec_blk_4way)
/* input:
* %rdi: ctx
* %rsi: dst
* %rdx: src
+ * %rcx: cbc (bool)
*/
pushq %r12;
pushq %rbx;
+ pushq %rcx;
+ pushq %rdx;
movq %rdi, CTX;
- movq %rsi, %r11
+ movq %rsi, %r11;
movq %rdx, RIO;
preload_roundkey_dec(17);
@@ -321,6 +337,14 @@ SYM_TYPED_FUNC_START(blowfish_dec_blk_4way)
round_dec4(3);
add_preloaded_roundkey4();
+ popq RIO;
+ popq %r12;
+ testq %r12, %r12;
+ jz .L_no_cbc_xor;
+
+ xor_block4();
+
+.L_no_cbc_xor:
movq %r11, RIO;
write_block4();
@@ -328,4 +352,4 @@ SYM_TYPED_FUNC_START(blowfish_dec_blk_4way)
popq %r12;
RET;
-SYM_FUNC_END(blowfish_dec_blk_4way)
+SYM_FUNC_END(__blowfish_dec_blk_4way)
diff --git a/arch/x86/crypto/blowfish_glue.c b/arch/x86/crypto/blowfish_glue.c
index 13a6664a89f3..552f2df0643f 100644
--- a/arch/x86/crypto/blowfish_glue.c
+++ b/arch/x86/crypto/blowfish_glue.c
@@ -16,6 +16,8 @@
#include <linux/module.h>
#include <linux/types.h>
+#include "ecb_cbc_helpers.h"
+
/* regular block cipher functions */
asmlinkage void blowfish_enc_blk(struct bf_ctx *ctx, u8 *dst, const u8 *src);
asmlinkage void blowfish_dec_blk(struct bf_ctx *ctx, u8 *dst, const u8 *src);
@@ -23,8 +25,20 @@ asmlinkage void blowfish_dec_blk(struct bf_ctx *ctx, u8 *dst, const u8 *src);
/* 4-way parallel cipher functions */
asmlinkage void blowfish_enc_blk_4way(struct bf_ctx *ctx, u8 *dst,
const u8 *src);
-asmlinkage void blowfish_dec_blk_4way(struct bf_ctx *ctx, u8 *dst,
- const u8 *src);
+asmlinkage void __blowfish_dec_blk_4way(struct bf_ctx *ctx, u8 *dst,
+ const u8 *src, bool cbc);
+
+static inline void blowfish_dec_ecb_4way(struct bf_ctx *ctx, u8 *dst,
+ const u8 *src)
+{
+ return __blowfish_dec_blk_4way(ctx, dst, src, false);
+}
+
+static inline void blowfish_dec_cbc_4way(struct bf_ctx *ctx, u8 *dst,
+ const u8 *src)
+{
+ return __blowfish_dec_blk_4way(ctx, dst, src, true);
+}
static void blowfish_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
{
@@ -42,183 +56,35 @@ static int blowfish_setkey_skcipher(struct crypto_skcipher *tfm,
return blowfish_setkey(&tfm->base, key, keylen);
}
-static int ecb_crypt(struct skcipher_request *req,
- void (*fn)(struct bf_ctx *, u8 *, const u8 *),
- void (*fn_4way)(struct bf_ctx *, u8 *, const u8 *))
-{
- unsigned int bsize = BF_BLOCK_SIZE;
- struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
- struct bf_ctx *ctx = crypto_skcipher_ctx(tfm);
- struct skcipher_walk walk;
- unsigned int nbytes;
- int err;
-
- err = skcipher_walk_virt(&walk, req, false);
-
- while ((nbytes = walk.nbytes)) {
- u8 *wsrc = walk.src.virt.addr;
- u8 *wdst = walk.dst.virt.addr;
-
- /* Process four block batch */
- if (nbytes >= bsize * 4) {
- do {
- fn_4way(ctx, wdst, wsrc);
-
- wsrc += bsize * 4;
- wdst += bsize * 4;
- nbytes -= bsize * 4;
- } while (nbytes >= bsize * 4);
-
- if (nbytes < bsize)
- goto done;
- }
-
- /* Handle leftovers */
- do {
- fn(ctx, wdst, wsrc);
-
- wsrc += bsize;
- wdst += bsize;
- nbytes -= bsize;
- } while (nbytes >= bsize);
-
-done:
- err = skcipher_walk_done(&walk, nbytes);
- }
-
- return err;
-}
-
static int ecb_encrypt(struct skcipher_request *req)
{
- return ecb_crypt(req, blowfish_enc_blk, blowfish_enc_blk_4way);
+ ECB_WALK_START(req, BF_BLOCK_SIZE, -1);
+ ECB_BLOCK(4, blowfish_enc_blk_4way);
+ ECB_BLOCK(1, blowfish_enc_blk);
+ ECB_WALK_END();
}
static int ecb_decrypt(struct skcipher_request *req)
{
- return ecb_crypt(req, blowfish_dec_blk, blowfish_dec_blk_4way);
-}
-
-static unsigned int __cbc_encrypt(struct bf_ctx *ctx,
- struct skcipher_walk *walk)
-{
- unsigned int bsize = BF_BLOCK_SIZE;
- unsigned int nbytes = walk->nbytes;
- u64 *src = (u64 *)walk->src.virt.addr;
- u64 *dst = (u64 *)walk->dst.virt.addr;
- u64 *iv = (u64 *)walk->iv;
-
- do {
- *dst = *src ^ *iv;
- blowfish_enc_blk(ctx, (u8 *)dst, (u8 *)dst);
- iv = dst;
-
- src += 1;
- dst += 1;
- nbytes -= bsize;
- } while (nbytes >= bsize);
-
- *(u64 *)walk->iv = *iv;
- return nbytes;
+ ECB_WALK_START(req, BF_BLOCK_SIZE, -1);
+ ECB_BLOCK(4, blowfish_dec_ecb_4way);
+ ECB_BLOCK(1, blowfish_dec_blk);
+ ECB_WALK_END();
}
static int cbc_encrypt(struct skcipher_request *req)
{
- struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
- struct bf_ctx *ctx = crypto_skcipher_ctx(tfm);
- struct skcipher_walk walk;
- unsigned int nbytes;
- int err;
-
- err = skcipher_walk_virt(&walk, req, false);
-
- while (walk.nbytes) {
- nbytes = __cbc_encrypt(ctx, &walk);
- err = skcipher_walk_done(&walk, nbytes);
- }
-
- return err;
-}
-
-static unsigned int __cbc_decrypt(struct bf_ctx *ctx,
- struct skcipher_walk *walk)
-{
- unsigned int bsize = BF_BLOCK_SIZE;
- unsigned int nbytes = walk->nbytes;
- u64 *src = (u64 *)walk->src.virt.addr;
- u64 *dst = (u64 *)walk->dst.virt.addr;
- u64 ivs[4 - 1];
- u64 last_iv;
-
- /* Start of the last block. */
- src += nbytes / bsize - 1;
- dst += nbytes / bsize - 1;
-
- last_iv = *src;
-
- /* Process four block batch */
- if (nbytes >= bsize * 4) {
- do {
- nbytes -= bsize * 4 - bsize;
- src -= 4 - 1;
- dst -= 4 - 1;
-
- ivs[0] = src[0];
- ivs[1] = src[1];
- ivs[2] = src[2];
-
- blowfish_dec_blk_4way(ctx, (u8 *)dst, (u8 *)src);
-
- dst[1] ^= ivs[0];
- dst[2] ^= ivs[1];
- dst[3] ^= ivs[2];
-
- nbytes -= bsize;
- if (nbytes < bsize)
- goto done;
-
- *dst ^= *(src - 1);
- src -= 1;
- dst -= 1;
- } while (nbytes >= bsize * 4);
- }
-
- /* Handle leftovers */
- for (;;) {
- blowfish_dec_blk(ctx, (u8 *)dst, (u8 *)src);
-
- nbytes -= bsize;
- if (nbytes < bsize)
- break;
-
- *dst ^= *(src - 1);
- src -= 1;
- dst -= 1;
- }
-
-done:
- *dst ^= *(u64 *)walk->iv;
- *(u64 *)walk->iv = last_iv;
-
- return nbytes;
+ CBC_WALK_START(req, BF_BLOCK_SIZE, -1);
+ CBC_ENC_BLOCK(blowfish_enc_blk);
+ CBC_WALK_END();
}
static int cbc_decrypt(struct skcipher_request *req)
{
- struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
- struct bf_ctx *ctx = crypto_skcipher_ctx(tfm);
- struct skcipher_walk walk;
- unsigned int nbytes;
- int err;
-
- err = skcipher_walk_virt(&walk, req, false);
-
- while (walk.nbytes) {
- nbytes = __cbc_decrypt(ctx, &walk);
- err = skcipher_walk_done(&walk, nbytes);
- }
-
- return err;
+ CBC_WALK_START(req, BF_BLOCK_SIZE, -1);
+ CBC_DEC_BLOCK(4, blowfish_dec_cbc_4way);
+ CBC_DEC_BLOCK(1, blowfish_dec_blk);
+ CBC_WALK_END();
}
static struct crypto_alg bf_cipher_alg = {
--
2.39.1
