From 8ce5fac2dc1bf64e1e6d2371e4ff9a9bfe8fd49f Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Fri, 16 Aug 2019 15:21:50 +0300 Subject: [PATCH] crypto: x86/xts - implement support for ciphertext stealing Align the x86 code with the generic XTS template, which now supports ciphertext stealing as described by the IEEE XTS-AES spec P1619. Tested-by: Stephan Mueller Signed-off-by: Ard Biesheuvel Signed-off-by: Herbert Xu --- arch/x86/crypto/aesni-intel_glue.c | 6 ++- arch/x86/crypto/camellia_aesni_avx2_glue.c | 4 +- arch/x86/crypto/camellia_aesni_avx_glue.c | 4 +- arch/x86/crypto/cast6_avx_glue.c | 4 +- arch/x86/crypto/glue_helper.c | 67 ++++++++++++++++++++++++++++-- arch/x86/crypto/serpent_avx2_glue.c | 4 +- arch/x86/crypto/serpent_avx_glue.c | 4 +- arch/x86/crypto/twofish_avx_glue.c | 4 +- arch/x86/include/asm/crypto/glue_helper.h | 2 +- 9 files changed, 81 insertions(+), 18 deletions(-) diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c index ef165d8..bf12bb7 100644 --- a/arch/x86/crypto/aesni-intel_glue.c +++ b/arch/x86/crypto/aesni-intel_glue.c @@ -609,7 +609,8 @@ static int xts_encrypt(struct skcipher_request *req) return glue_xts_req_128bit(&aesni_enc_xts, req, XTS_TWEAK_CAST(aesni_xts_tweak), aes_ctx(ctx->raw_tweak_ctx), - aes_ctx(ctx->raw_crypt_ctx)); + aes_ctx(ctx->raw_crypt_ctx), + false); } static int xts_decrypt(struct skcipher_request *req) @@ -620,7 +621,8 @@ static int xts_decrypt(struct skcipher_request *req) return glue_xts_req_128bit(&aesni_dec_xts, req, XTS_TWEAK_CAST(aesni_xts_tweak), aes_ctx(ctx->raw_tweak_ctx), - aes_ctx(ctx->raw_crypt_ctx)); + aes_ctx(ctx->raw_crypt_ctx), + true); } static int diff --git a/arch/x86/crypto/camellia_aesni_avx2_glue.c b/arch/x86/crypto/camellia_aesni_avx2_glue.c index abf298c..a4f0012 100644 --- a/arch/x86/crypto/camellia_aesni_avx2_glue.c +++ b/arch/x86/crypto/camellia_aesni_avx2_glue.c @@ -182,7 +182,7 @@ static int xts_encrypt(struct skcipher_request *req) return glue_xts_req_128bit(&camellia_enc_xts, req, XTS_TWEAK_CAST(camellia_enc_blk), - &ctx->tweak_ctx, &ctx->crypt_ctx); + &ctx->tweak_ctx, &ctx->crypt_ctx, false); } static int xts_decrypt(struct skcipher_request *req) @@ -192,7 +192,7 @@ static int xts_decrypt(struct skcipher_request *req) return glue_xts_req_128bit(&camellia_dec_xts, req, XTS_TWEAK_CAST(camellia_enc_blk), - &ctx->tweak_ctx, &ctx->crypt_ctx); + &ctx->tweak_ctx, &ctx->crypt_ctx, true); } static struct skcipher_alg camellia_algs[] = { diff --git a/arch/x86/crypto/camellia_aesni_avx_glue.c b/arch/x86/crypto/camellia_aesni_avx_glue.c index 0c22d84..f28d282 100644 --- a/arch/x86/crypto/camellia_aesni_avx_glue.c +++ b/arch/x86/crypto/camellia_aesni_avx_glue.c @@ -208,7 +208,7 @@ static int xts_encrypt(struct skcipher_request *req) return glue_xts_req_128bit(&camellia_enc_xts, req, XTS_TWEAK_CAST(camellia_enc_blk), - &ctx->tweak_ctx, &ctx->crypt_ctx); + &ctx->tweak_ctx, &ctx->crypt_ctx, false); } static int xts_decrypt(struct skcipher_request *req) @@ -218,7 +218,7 @@ static int xts_decrypt(struct skcipher_request *req) return glue_xts_req_128bit(&camellia_dec_xts, req, XTS_TWEAK_CAST(camellia_enc_blk), - &ctx->tweak_ctx, &ctx->crypt_ctx); + &ctx->tweak_ctx, &ctx->crypt_ctx, true); } static struct skcipher_alg camellia_algs[] = { diff --git a/arch/x86/crypto/cast6_avx_glue.c b/arch/x86/crypto/cast6_avx_glue.c index 645f8f1..a8a38ff 100644 --- a/arch/x86/crypto/cast6_avx_glue.c +++ b/arch/x86/crypto/cast6_avx_glue.c @@ -201,7 +201,7 @@ static int xts_encrypt(struct skcipher_request *req) return glue_xts_req_128bit(&cast6_enc_xts, req, XTS_TWEAK_CAST(__cast6_encrypt), - &ctx->tweak_ctx, &ctx->crypt_ctx); + &ctx->tweak_ctx, &ctx->crypt_ctx, false); } static int xts_decrypt(struct skcipher_request *req) @@ -211,7 +211,7 @@ static int xts_decrypt(struct skcipher_request *req) return glue_xts_req_128bit(&cast6_dec_xts, req, XTS_TWEAK_CAST(__cast6_encrypt), - &ctx->tweak_ctx, &ctx->crypt_ctx); + &ctx->tweak_ctx, &ctx->crypt_ctx, true); } static struct skcipher_alg cast6_algs[] = { diff --git a/arch/x86/crypto/glue_helper.c b/arch/x86/crypto/glue_helper.c index 9015514..d15b993 100644 --- a/arch/x86/crypto/glue_helper.c +++ b/arch/x86/crypto/glue_helper.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include @@ -259,17 +260,36 @@ done: int glue_xts_req_128bit(const struct common_glue_ctx *gctx, struct skcipher_request *req, common_glue_func_t tweak_fn, void *tweak_ctx, - void *crypt_ctx) + void *crypt_ctx, bool decrypt) { + 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 +307,47 @@ int glue_xts_req_128bit(const struct common_glue_ctx *gctx, nbytes = walk.nbytes; } + if (unlikely(cts)) { + u8 *next_tweak, *final_tweak = req->iv; + struct scatterlist *src, *dst; + struct scatterlist s[2], d[2]; + 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 (decrypt) { + 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, + final_tweak); + + err = skcipher_walk_virt(&walk, req, false) ?: + skcipher_walk_done(&walk, + __glue_xts_req_128bit(gctx, crypt_ctx, &walk)); + } + +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 b871728..13fd8d3 100644 --- a/arch/x86/crypto/serpent_avx2_glue.c +++ b/arch/x86/crypto/serpent_avx2_glue.c @@ -167,7 +167,7 @@ static int xts_encrypt(struct skcipher_request *req) return glue_xts_req_128bit(&serpent_enc_xts, req, XTS_TWEAK_CAST(__serpent_encrypt), - &ctx->tweak_ctx, &ctx->crypt_ctx); + &ctx->tweak_ctx, &ctx->crypt_ctx, false); } static int xts_decrypt(struct skcipher_request *req) @@ -177,7 +177,7 @@ static int xts_decrypt(struct skcipher_request *req) return glue_xts_req_128bit(&serpent_dec_xts, req, XTS_TWEAK_CAST(__serpent_encrypt), - &ctx->tweak_ctx, &ctx->crypt_ctx); + &ctx->tweak_ctx, &ctx->crypt_ctx, true); } static struct skcipher_alg serpent_algs[] = { diff --git a/arch/x86/crypto/serpent_avx_glue.c b/arch/x86/crypto/serpent_avx_glue.c index 4a9a9f2..7d3dca3 100644 --- a/arch/x86/crypto/serpent_avx_glue.c +++ b/arch/x86/crypto/serpent_avx_glue.c @@ -207,7 +207,7 @@ static int xts_encrypt(struct skcipher_request *req) return glue_xts_req_128bit(&serpent_enc_xts, req, XTS_TWEAK_CAST(__serpent_encrypt), - &ctx->tweak_ctx, &ctx->crypt_ctx); + &ctx->tweak_ctx, &ctx->crypt_ctx, false); } static int xts_decrypt(struct skcipher_request *req) @@ -217,7 +217,7 @@ static int xts_decrypt(struct skcipher_request *req) return glue_xts_req_128bit(&serpent_dec_xts, req, XTS_TWEAK_CAST(__serpent_encrypt), - &ctx->tweak_ctx, &ctx->crypt_ctx); + &ctx->tweak_ctx, &ctx->crypt_ctx, true); } static struct skcipher_alg serpent_algs[] = { diff --git a/arch/x86/crypto/twofish_avx_glue.c b/arch/x86/crypto/twofish_avx_glue.c index 0dbf8e8..d561c82 100644 --- a/arch/x86/crypto/twofish_avx_glue.c +++ b/arch/x86/crypto/twofish_avx_glue.c @@ -210,7 +210,7 @@ static int xts_encrypt(struct skcipher_request *req) return glue_xts_req_128bit(&twofish_enc_xts, req, XTS_TWEAK_CAST(twofish_enc_blk), - &ctx->tweak_ctx, &ctx->crypt_ctx); + &ctx->tweak_ctx, &ctx->crypt_ctx, false); } static int xts_decrypt(struct skcipher_request *req) @@ -220,7 +220,7 @@ static int xts_decrypt(struct skcipher_request *req) return glue_xts_req_128bit(&twofish_dec_xts, req, XTS_TWEAK_CAST(twofish_enc_blk), - &ctx->tweak_ctx, &ctx->crypt_ctx); + &ctx->tweak_ctx, &ctx->crypt_ctx, true); } static struct skcipher_alg twofish_algs[] = { diff --git a/arch/x86/include/asm/crypto/glue_helper.h b/arch/x86/include/asm/crypto/glue_helper.h index d181863..8d4a8e1 100644 --- a/arch/x86/include/asm/crypto/glue_helper.h +++ b/arch/x86/include/asm/crypto/glue_helper.h @@ -114,7 +114,7 @@ extern int glue_ctr_req_128bit(const struct common_glue_ctx *gctx, extern int glue_xts_req_128bit(const struct common_glue_ctx *gctx, struct skcipher_request *req, common_glue_func_t tweak_fn, void *tweak_ctx, - void *crypt_ctx); + void *crypt_ctx, bool decrypt); extern void glue_xts_crypt_128bit_one(void *ctx, u128 *dst, const u128 *src, le128 *iv, common_glue_func_t fn); -- 2.7.4