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[v6,6/8] crypto: x86/aesni: Remove glue function macro usage

Message ID 20191122010334.12081-7-keescook@chromium.org (mailing list archive)
State New, archived
Headers show
Series crypto: x86: Fix indirect function call casts | expand

Commit Message

Kees Cook Nov. 22, 2019, 1:03 a.m. UTC 
In order to remove the callsite function casts, regularize the function
prototypes for helpers to avoid triggering Control-Flow Integrity checks
during indirect function calls. Where needed, to avoid changes to
pointer math, u8 pointers are internally cast back to u128 pointers.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/x86/crypto/aesni-intel_asm.S  |  8 +++---
 arch/x86/crypto/aesni-intel_glue.c | 45 ++++++++++++------------------
 2 files changed, 22 insertions(+), 31 deletions(-)

Comments

Eric Biggers Nov. 22, 2019, 2:08 a.m. UTC | #1 
On Thu, Nov 21, 2019 at 05:03:32PM -0800, Kees Cook wrote:
> In order to remove the callsite function casts, regularize the function
> prototypes for helpers to avoid triggering Control-Flow Integrity checks
> during indirect function calls. Where needed, to avoid changes to
> pointer math, u8 pointers are internally cast back to u128 pointers.
> 
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
>  arch/x86/crypto/aesni-intel_asm.S  |  8 +++---
>  arch/x86/crypto/aesni-intel_glue.c | 45 ++++++++++++------------------
>  2 files changed, 22 insertions(+), 31 deletions(-)
> 
> diff --git a/arch/x86/crypto/aesni-intel_asm.S b/arch/x86/crypto/aesni-intel_asm.S
> index e40bdf024ba7..89e5e574dc95 100644
> --- a/arch/x86/crypto/aesni-intel_asm.S
> +++ b/arch/x86/crypto/aesni-intel_asm.S
> @@ -1946,7 +1946,7 @@ ENTRY(aesni_set_key)
>  ENDPROC(aesni_set_key)
>  
>  /*
> - * void aesni_enc(struct crypto_aes_ctx *ctx, u8 *dst, const u8 *src)
> + * void aesni_enc(void *ctx, u8 *dst, const u8 *src)
>   */

This doesn't exactly match the C prototype.

>  ENTRY(aesni_enc)
>  	FRAME_BEGIN
> @@ -2137,7 +2137,7 @@ _aesni_enc4:
>  ENDPROC(_aesni_enc4)
>  
>  /*
> - * void aesni_dec (struct crypto_aes_ctx *ctx, u8 *dst, const u8 *src)
> + * void aesni_dec (void *ctx, u8 *dst, const u8 *src)
>   */
>  ENTRY(aesni_dec)

Likewise.

>  	FRAME_BEGIN
> @@ -2726,8 +2726,8 @@ ENDPROC(aesni_ctr_enc)
>  	pxor CTR, IV;
>  
>  /*
> - * void aesni_xts_crypt8(struct crypto_aes_ctx *ctx, const u8 *dst, u8 *src,
> - *			 bool enc, u8 *iv)
> + * void aesni_xts_crypt8(void *ctx, u8 *dst, const u8 *src, bool enc,
> + *			 le128 *iv)
>   */

Likewise.  This one is particularly strange because the first argument was
changed to void * here, but in C it's 'const struct crypto_aes_ctx *ctx'.
 
- Eric
diff mbox series

Patch

diff --git a/arch/x86/crypto/aesni-intel_asm.S b/arch/x86/crypto/aesni-intel_asm.S
index e40bdf024ba7..89e5e574dc95 100644
--- a/arch/x86/crypto/aesni-intel_asm.S
+++ b/arch/x86/crypto/aesni-intel_asm.S
@@ -1946,7 +1946,7 @@  ENTRY(aesni_set_key)
 ENDPROC(aesni_set_key)
 
 /*
- * void aesni_enc(struct crypto_aes_ctx *ctx, u8 *dst, const u8 *src)
+ * void aesni_enc(void *ctx, u8 *dst, const u8 *src)
  */
 ENTRY(aesni_enc)
 	FRAME_BEGIN
@@ -2137,7 +2137,7 @@  _aesni_enc4:
 ENDPROC(_aesni_enc4)
 
 /*
- * void aesni_dec (struct crypto_aes_ctx *ctx, u8 *dst, const u8 *src)
+ * void aesni_dec (void *ctx, u8 *dst, const u8 *src)
  */
 ENTRY(aesni_dec)
 	FRAME_BEGIN
@@ -2726,8 +2726,8 @@  ENDPROC(aesni_ctr_enc)
 	pxor CTR, IV;
 
 /*
- * void aesni_xts_crypt8(struct crypto_aes_ctx *ctx, const u8 *dst, u8 *src,
- *			 bool enc, u8 *iv)
+ * void aesni_xts_crypt8(void *ctx, u8 *dst, const u8 *src, bool enc,
+ *			 le128 *iv)
  */
 ENTRY(aesni_xts_crypt8)
 	FRAME_BEGIN
diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c
index 3e707e81afdb..670f8fcf2544 100644
--- a/arch/x86/crypto/aesni-intel_glue.c
+++ b/arch/x86/crypto/aesni-intel_glue.c
@@ -83,10 +83,8 @@  struct gcm_context_data {
 
 asmlinkage int aesni_set_key(struct crypto_aes_ctx *ctx, const u8 *in_key,
 			     unsigned int key_len);
-asmlinkage void aesni_enc(struct crypto_aes_ctx *ctx, u8 *out,
-			  const u8 *in);
-asmlinkage void aesni_dec(struct crypto_aes_ctx *ctx, u8 *out,
-			  const u8 *in);
+asmlinkage void aesni_enc(const void *ctx, u8 *out, const u8 *in);
+asmlinkage void aesni_dec(const void *ctx, u8 *out, const u8 *in);
 asmlinkage void aesni_ecb_enc(struct crypto_aes_ctx *ctx, u8 *out,
 			      const u8 *in, unsigned int len);
 asmlinkage void aesni_ecb_dec(struct crypto_aes_ctx *ctx, u8 *out,
@@ -106,8 +104,8 @@  static void (*aesni_ctr_enc_tfm)(struct crypto_aes_ctx *ctx, u8 *out,
 asmlinkage void aesni_ctr_enc(struct crypto_aes_ctx *ctx, u8 *out,
 			      const u8 *in, unsigned int len, u8 *iv);
 
-asmlinkage void aesni_xts_crypt8(struct crypto_aes_ctx *ctx, u8 *out,
-				 const u8 *in, bool enc, u8 *iv);
+asmlinkage void aesni_xts_crypt8(const struct crypto_aes_ctx *ctx, u8 *out,
+				 const u8 *in, bool enc, le128 *iv);
 
 /* asmlinkage void aesni_gcm_enc()
  * void *ctx,  AES Key schedule. Starts on a 16 byte boundary.
@@ -550,29 +548,24 @@  static int xts_aesni_setkey(struct crypto_skcipher *tfm, const u8 *key,
 }
 
 
-static void aesni_xts_tweak(void *ctx, u8 *out, const u8 *in)
+static void aesni_xts_enc(const void *ctx, u8 *dst, const u8 *src, le128 *iv)
 {
-	aesni_enc(ctx, out, in);
+	glue_xts_crypt_128bit_one(ctx, dst, src, iv, aesni_enc);
 }
 
-static void aesni_xts_enc(void *ctx, u128 *dst, const u128 *src, le128 *iv)
+static void aesni_xts_dec(const void *ctx, u8 *dst, const u8 *src, le128 *iv)
 {
-	glue_xts_crypt_128bit_one(ctx, dst, src, iv, GLUE_FUNC_CAST(aesni_enc));
+	glue_xts_crypt_128bit_one(ctx, dst, src, iv, aesni_dec);
 }
 
-static void aesni_xts_dec(void *ctx, u128 *dst, const u128 *src, le128 *iv)
+static void aesni_xts_enc8(const void *ctx, u8 *dst, const u8 *src, le128 *iv)
 {
-	glue_xts_crypt_128bit_one(ctx, dst, src, iv, GLUE_FUNC_CAST(aesni_dec));
+	aesni_xts_crypt8(ctx, dst, src, true, iv);
 }
 
-static void aesni_xts_enc8(void *ctx, u128 *dst, const u128 *src, le128 *iv)
+static void aesni_xts_dec8(const void *ctx, u8 *dst, const u8 *src, le128 *iv)
 {
-	aesni_xts_crypt8(ctx, (u8 *)dst, (const u8 *)src, true, (u8 *)iv);
-}
-
-static void aesni_xts_dec8(void *ctx, u128 *dst, const u128 *src, le128 *iv)
-{
-	aesni_xts_crypt8(ctx, (u8 *)dst, (const u8 *)src, false, (u8 *)iv);
+	aesni_xts_crypt8(ctx, dst, src, false, iv);
 }
 
 static const struct common_glue_ctx aesni_enc_xts = {
@@ -581,10 +574,10 @@  static const struct common_glue_ctx aesni_enc_xts = {
 
 	.funcs = { {
 		.num_blocks = 8,
-		.fn_u = { .xts = GLUE_XTS_FUNC_CAST(aesni_xts_enc8) }
+		.fn_u = { .xts = aesni_xts_enc8 }
 	}, {
 		.num_blocks = 1,
-		.fn_u = { .xts = GLUE_XTS_FUNC_CAST(aesni_xts_enc) }
+		.fn_u = { .xts = aesni_xts_enc }
 	} }
 };
 
@@ -594,10 +587,10 @@  static const struct common_glue_ctx aesni_dec_xts = {
 
 	.funcs = { {
 		.num_blocks = 8,
-		.fn_u = { .xts = GLUE_XTS_FUNC_CAST(aesni_xts_dec8) }
+		.fn_u = { .xts = aesni_xts_dec8 }
 	}, {
 		.num_blocks = 1,
-		.fn_u = { .xts = GLUE_XTS_FUNC_CAST(aesni_xts_dec) }
+		.fn_u = { .xts = aesni_xts_dec }
 	} }
 };
 
@@ -606,8 +599,7 @@  static int xts_encrypt(struct skcipher_request *req)
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 	struct aesni_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
 
-	return glue_xts_req_128bit(&aesni_enc_xts, req,
-				   XTS_TWEAK_CAST(aesni_xts_tweak),
+	return glue_xts_req_128bit(&aesni_enc_xts, req, aesni_enc,
 				   aes_ctx(ctx->raw_tweak_ctx),
 				   aes_ctx(ctx->raw_crypt_ctx),
 				   false);
@@ -618,8 +610,7 @@  static int xts_decrypt(struct skcipher_request *req)
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 	struct aesni_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
 
-	return glue_xts_req_128bit(&aesni_dec_xts, req,
-				   XTS_TWEAK_CAST(aesni_xts_tweak),
+	return glue_xts_req_128bit(&aesni_dec_xts, req, aesni_enc,
 				   aes_ctx(ctx->raw_tweak_ctx),
 				   aes_ctx(ctx->raw_crypt_ctx),
 				   true);