Align the x86 code with the generic XTS template, which now supports
ciphertext stealing as described by the IEEE XTS-AES spec P1619.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
---
arch/x86/crypto/aesni-intel_glue.c | 1 +
arch/x86/crypto/camellia_aesni_avx2_glue.c | 1 +
arch/x86/crypto/camellia_aesni_avx_glue.c | 1 +
arch/x86/crypto/cast6_avx_glue.c | 1 +
arch/x86/crypto/glue_helper.c | 70 +++++++++++++++++++++-
arch/x86/crypto/serpent_avx2_glue.c | 1 +
arch/x86/crypto/serpent_avx_glue.c | 1 +
arch/x86/crypto/twofish_avx_glue.c | 1 +
arch/x86/include/asm/crypto/glue_helper.h | 1 +
9 files changed, 76 insertions(+), 2 deletions(-)
diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c
index ef165d8cf443..0ea1517faf09 100644
--- a/arch/x86/crypto/aesni-intel_glue.c
+++ b/arch/x86/crypto/aesni-intel_glue.c
@@ -591,6 +591,7 @@ static const struct common_glue_ctx aesni_enc_xts = {
static const struct common_glue_ctx aesni_dec_xts = {
.num_funcs = 2,
.fpu_blocks_limit = 1,
+ .xts_decrypt = 1,
.funcs = { {
.num_blocks = 8,
diff --git a/arch/x86/crypto/camellia_aesni_avx2_glue.c b/arch/x86/crypto/camellia_aesni_avx2_glue.c
index abf298c272dc..7854378e6d0c 100644
--- a/arch/x86/crypto/camellia_aesni_avx2_glue.c
+++ b/arch/x86/crypto/camellia_aesni_avx2_glue.c
@@ -129,6 +129,7 @@ static const struct common_glue_ctx camellia_dec_cbc = {
static const struct common_glue_ctx camellia_dec_xts = {
.num_funcs = 3,
.fpu_blocks_limit = CAMELLIA_AESNI_PARALLEL_BLOCKS,
+ .xts_decrypt = 1,
.funcs = { {
.num_blocks = CAMELLIA_AESNI_AVX2_PARALLEL_BLOCKS,
diff --git a/arch/x86/crypto/camellia_aesni_avx_glue.c b/arch/x86/crypto/camellia_aesni_avx_glue.c
index 0c22d84750a3..58e8f08819b6 100644
--- a/arch/x86/crypto/camellia_aesni_avx_glue.c
+++ b/arch/x86/crypto/camellia_aesni_avx_glue.c
@@ -136,6 +136,7 @@ static const struct common_glue_ctx camellia_dec_cbc = {
static const struct common_glue_ctx camellia_dec_xts = {
.num_funcs = 2,
.fpu_blocks_limit = CAMELLIA_AESNI_PARALLEL_BLOCKS,
+ .xts_decrypt = 1,
.funcs = { {
.num_blocks = CAMELLIA_AESNI_PARALLEL_BLOCKS,
diff --git a/arch/x86/crypto/cast6_avx_glue.c b/arch/x86/crypto/cast6_avx_glue.c
index 645f8f16815c..dfdbdeff5a2b 100644
--- a/arch/x86/crypto/cast6_avx_glue.c
+++ b/arch/x86/crypto/cast6_avx_glue.c
@@ -132,6 +132,7 @@ static const struct common_glue_ctx cast6_dec_cbc = {
static const struct common_glue_ctx cast6_dec_xts = {
.num_funcs = 2,
.fpu_blocks_limit = CAST6_PARALLEL_BLOCKS,
+ .xts_decrypt = 1,
.funcs = { {
.num_blocks = CAST6_PARALLEL_BLOCKS,
diff --git a/arch/x86/crypto/glue_helper.c b/arch/x86/crypto/glue_helper.c
index 901551445387..693541d00c0a 100644
--- a/arch/x86/crypto/glue_helper.c
+++ b/arch/x86/crypto/glue_helper.c
@@ -14,6 +14,7 @@
#include <crypto/b128ops.h>
#include <crypto/gf128mul.h>
#include <crypto/internal/skcipher.h>
+#include <crypto/scatterwalk.h>
#include <crypto/xts.h>
#include <asm/crypto/glue_helper.h>
@@ -261,15 +262,34 @@ int glue_xts_req_128bit(const struct common_glue_ctx *gctx,
common_glue_func_t tweak_fn, void *tweak_ctx,
void *crypt_ctx)
{
+ const bool cts = (req->cryptlen % XTS_BLOCK_SIZE);
const unsigned int bsize = 128 / 8;
+ struct skcipher_request subreq;
struct skcipher_walk walk;
bool fpu_enabled = false;
- unsigned int nbytes;
+ unsigned int nbytes, tail;
int err;
+ if (req->cryptlen < XTS_BLOCK_SIZE)
+ return -EINVAL;
+
+ if (unlikely(cts)) {
+ struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+
+ tail = req->cryptlen % XTS_BLOCK_SIZE + XTS_BLOCK_SIZE;
+
+ skcipher_request_set_tfm(&subreq, tfm);
+ skcipher_request_set_callback(&subreq,
+ crypto_skcipher_get_flags(tfm),
+ NULL, NULL);
+ skcipher_request_set_crypt(&subreq, req->src, req->dst,
+ req->cryptlen - tail, req->iv);
+ req = &subreq;
+ }
+
err = skcipher_walk_virt(&walk, req, false);
nbytes = walk.nbytes;
- if (!nbytes)
+ if (err)
return err;
/* set minimum length to bsize, for tweak_fn */
@@ -287,6 +307,52 @@ int glue_xts_req_128bit(const struct common_glue_ctx *gctx,
nbytes = walk.nbytes;
}
+ if (unlikely(cts)) {
+ struct scatterlist *src, *dst;
+ struct scatterlist s[2], d[2];
+ le128 final_tweak;
+ u8 *next_tweak;
+ le128 b[2];
+
+ dst = src = scatterwalk_ffwd(s, req->src, req->cryptlen);
+ if (req->dst != req->src)
+ dst = scatterwalk_ffwd(d, req->dst, req->cryptlen);
+
+ if (gctx->xts_decrypt) {
+ final_tweak = *(le128 *)req->iv;
+ next_tweak = memcpy(b, req->iv, XTS_BLOCK_SIZE);
+ gf128mul_x_ble(b, b);
+ } else {
+ next_tweak = req->iv;
+ }
+
+ skcipher_request_set_crypt(&subreq, src, dst, XTS_BLOCK_SIZE,
+ next_tweak);
+
+ err = skcipher_walk_virt(&walk, req, false) ?:
+ skcipher_walk_done(&walk,
+ __glue_xts_req_128bit(gctx, crypt_ctx, &walk));
+ if (err)
+ goto out;
+
+ scatterwalk_map_and_copy(b, dst, 0, XTS_BLOCK_SIZE, 0);
+ memcpy(b + 1, b, tail - XTS_BLOCK_SIZE);
+ scatterwalk_map_and_copy(b, src, XTS_BLOCK_SIZE,
+ tail - XTS_BLOCK_SIZE, 0);
+ scatterwalk_map_and_copy(b, dst, 0, tail, 1);
+
+ skcipher_request_set_crypt(&subreq, dst, dst, XTS_BLOCK_SIZE,
+ gctx->xts_decrypt ? (u8 *)&final_tweak
+ : req->iv);
+
+ err = skcipher_walk_virt(&walk, req, false) ?:
+ skcipher_walk_done(&walk,
+ __glue_xts_req_128bit(gctx, crypt_ctx, &walk));
+ if (err)
+ goto out;
+ }
+
+out:
glue_fpu_end(fpu_enabled);
return err;
diff --git a/arch/x86/crypto/serpent_avx2_glue.c b/arch/x86/crypto/serpent_avx2_glue.c
index b871728e0b2f..b7b82bf69a67 100644
--- a/arch/x86/crypto/serpent_avx2_glue.c
+++ b/arch/x86/crypto/serpent_avx2_glue.c
@@ -121,6 +121,7 @@ static const struct common_glue_ctx serpent_dec_cbc = {
static const struct common_glue_ctx serpent_dec_xts = {
.num_funcs = 3,
.fpu_blocks_limit = 8,
+ .xts_decrypt = 1,
.funcs = { {
.num_blocks = 16,
diff --git a/arch/x86/crypto/serpent_avx_glue.c b/arch/x86/crypto/serpent_avx_glue.c
index 4a9a9f2ee1d8..c46d722ecc12 100644
--- a/arch/x86/crypto/serpent_avx_glue.c
+++ b/arch/x86/crypto/serpent_avx_glue.c
@@ -164,6 +164,7 @@ static const struct common_glue_ctx serpent_dec_cbc = {
static const struct common_glue_ctx serpent_dec_xts = {
.num_funcs = 2,
.fpu_blocks_limit = SERPENT_PARALLEL_BLOCKS,
+ .xts_decrypt = 1,
.funcs = { {
.num_blocks = SERPENT_PARALLEL_BLOCKS,
diff --git a/arch/x86/crypto/twofish_avx_glue.c b/arch/x86/crypto/twofish_avx_glue.c
index 0dbf8e8b09d7..220de42bc3ab 100644
--- a/arch/x86/crypto/twofish_avx_glue.c
+++ b/arch/x86/crypto/twofish_avx_glue.c
@@ -167,6 +167,7 @@ static const struct common_glue_ctx twofish_dec_cbc = {
static const struct common_glue_ctx twofish_dec_xts = {
.num_funcs = 2,
.fpu_blocks_limit = TWOFISH_PARALLEL_BLOCKS,
+ .xts_decrypt = 1,
.funcs = { {
.num_blocks = TWOFISH_PARALLEL_BLOCKS,
diff --git a/arch/x86/include/asm/crypto/glue_helper.h b/arch/x86/include/asm/crypto/glue_helper.h
index d1818634ae7e..31e038759a54 100644
--- a/arch/x86/include/asm/crypto/glue_helper.h
+++ b/arch/x86/include/asm/crypto/glue_helper.h
@@ -36,6 +36,7 @@ struct common_glue_func_entry {
struct common_glue_ctx {
unsigned int num_funcs;
int fpu_blocks_limit; /* -1 means fpu not needed at all */
+ int xts_decrypt; /* whether this implements XTS decryption */
/*
* First funcs entry must have largest num_blocks and last funcs entry
--
2.17.1
