[CRYPTO] pcbc: Use crypto_xor

This patch replaces the custom xor in CBC with the generic crypto_xor. It changes the operations for in-place encryption slightly to avoid calling crypto_xor with tmpbuf since it is not necessarily aligned. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

[CRYPTO] pcbc: Use crypto_xor
This patch replaces the custom xor in CBC with the generic crypto_xor. It changes the operations for in-place encryption slightly to avoid calling crypto_xor with tmpbuf since it is not necessarily aligned. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Herbert Xu
1 parent 50b6544e13
Showing 1 changed file with 24 additions and 81 deletions Side-by-side Diff
crypto/pcbc.c
@@ -24,7 +24,6 @@
  
 struct crypto_pcbc_ctx {
 	struct crypto_cipher *child;
-	void (*xor)(u8 *dst, const u8 *src, unsigned int bs);
 };
  
 static int crypto_pcbc_setkey(struct crypto_tfm *parent, const u8 *key,
@@ -45,9 +44,7 @@
  
 static int crypto_pcbc_encrypt_segment(struct blkcipher_desc *desc,
 				       struct blkcipher_walk *walk,
-				       struct crypto_cipher *tfm,
-				       void (*xor)(u8 *, const u8 *,
-						   unsigned int))
+				       struct crypto_cipher *tfm)
 {
 	void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
 		crypto_cipher_alg(tfm)->cia_encrypt;
  
@@ -58,10 +55,10 @@
 	u8 *iv = walk->iv;
  
 	do {
-		xor(iv, src, bsize);
+		crypto_xor(iv, src, bsize);
 		fn(crypto_cipher_tfm(tfm), dst, iv);
 		memcpy(iv, dst, bsize);
-		xor(iv, src, bsize);
+		crypto_xor(iv, src, bsize);
  
 		src += bsize;
 		dst += bsize;
@@ -72,9 +69,7 @@
  
 static int crypto_pcbc_encrypt_inplace(struct blkcipher_desc *desc,
 				       struct blkcipher_walk *walk,
-				       struct crypto_cipher *tfm,
-				       void (*xor)(u8 *, const u8 *,
-						   unsigned int))
+				       struct crypto_cipher *tfm)
 {
 	void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
 		crypto_cipher_alg(tfm)->cia_encrypt;
  
@@ -86,10 +81,10 @@
  
 	do {
 		memcpy(tmpbuf, src, bsize);
-		xor(iv, tmpbuf, bsize);
+		crypto_xor(iv, src, bsize);
 		fn(crypto_cipher_tfm(tfm), src, iv);
-		memcpy(iv, src, bsize);
-		xor(iv, tmpbuf, bsize);
+		memcpy(iv, tmpbuf, bsize);
+		crypto_xor(iv, src, bsize);
  
 		src += bsize;
 	} while ((nbytes -= bsize) >= bsize);
@@ -107,7 +102,6 @@
 	struct crypto_blkcipher *tfm = desc->tfm;
 	struct crypto_pcbc_ctx *ctx = crypto_blkcipher_ctx(tfm);
 	struct crypto_cipher *child = ctx->child;
-	void (*xor)(u8 *, const u8 *, unsigned int bs) = ctx->xor;
 	int err;
  
 	blkcipher_walk_init(&walk, dst, src, nbytes);
  
@@ -115,11 +109,11 @@
  
 	while ((nbytes = walk.nbytes)) {
 		if (walk.src.virt.addr == walk.dst.virt.addr)
-			nbytes = crypto_pcbc_encrypt_inplace(desc, &walk, child,
-							     xor);
+			nbytes = crypto_pcbc_encrypt_inplace(desc, &walk,
+							     child);
 		else
-			nbytes = crypto_pcbc_encrypt_segment(desc, &walk, child,
-							     xor);
+			nbytes = crypto_pcbc_encrypt_segment(desc, &walk,
+							     child);
 		err = blkcipher_walk_done(desc, &walk, nbytes);
 	}
  
@@ -128,9 +122,7 @@
  
 static int crypto_pcbc_decrypt_segment(struct blkcipher_desc *desc,
 				       struct blkcipher_walk *walk,
-				       struct crypto_cipher *tfm,
-				       void (*xor)(u8 *, const u8 *,
-						   unsigned int))
+				       struct crypto_cipher *tfm)
 {
 	void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
 		crypto_cipher_alg(tfm)->cia_decrypt;
  
@@ -142,9 +134,9 @@
  
 	do {
 		fn(crypto_cipher_tfm(tfm), dst, src);
-		xor(dst, iv, bsize);
+		crypto_xor(dst, iv, bsize);
 		memcpy(iv, src, bsize);
-		xor(iv, dst, bsize);
+		crypto_xor(iv, dst, bsize);
  
 		src += bsize;
 		dst += bsize;
@@ -157,9 +149,7 @@
  
 static int crypto_pcbc_decrypt_inplace(struct blkcipher_desc *desc,
 				       struct blkcipher_walk *walk,
-				       struct crypto_cipher *tfm,
-				       void (*xor)(u8 *, const u8 *,
-						   unsigned int))
+				       struct crypto_cipher *tfm)
 {
 	void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
 		crypto_cipher_alg(tfm)->cia_decrypt;
  
@@ -172,9 +162,9 @@
 	do {
 		memcpy(tmpbuf, src, bsize);
 		fn(crypto_cipher_tfm(tfm), src, src);
-		xor(src, iv, bsize);
+		crypto_xor(src, iv, bsize);
 		memcpy(iv, tmpbuf, bsize);
-		xor(iv, src, bsize);
+		crypto_xor(iv, src, bsize);
  
 		src += bsize;
 	} while ((nbytes -= bsize) >= bsize);
@@ -192,7 +182,6 @@
 	struct crypto_blkcipher *tfm = desc->tfm;
 	struct crypto_pcbc_ctx *ctx = crypto_blkcipher_ctx(tfm);
 	struct crypto_cipher *child = ctx->child;
-	void (*xor)(u8 *, const u8 *, unsigned int bs) = ctx->xor;
 	int err;
  
 	blkcipher_walk_init(&walk, dst, src, nbytes);
  
  
@@ -200,48 +189,17 @@
  
 	while ((nbytes = walk.nbytes)) {
 		if (walk.src.virt.addr == walk.dst.virt.addr)
-			nbytes = crypto_pcbc_decrypt_inplace(desc, &walk, child,
-							     xor);
+			nbytes = crypto_pcbc_decrypt_inplace(desc, &walk,
+							     child);
 		else
-			nbytes = crypto_pcbc_decrypt_segment(desc, &walk, child,
-							     xor);
+			nbytes = crypto_pcbc_decrypt_segment(desc, &walk,
+							     child);
 		err = blkcipher_walk_done(desc, &walk, nbytes);
 	}
  
 	return err;
 }
  
-static void xor_byte(u8 *a, const u8 *b, unsigned int bs)
-{
-	do {
-		*a++ ^= *b++;
-	} while (--bs);
-}
-
-static void xor_quad(u8 *dst, const u8 *src, unsigned int bs)
-{
-	u32 *a = (u32 *)dst;
-	u32 *b = (u32 *)src;
-
-	do {
-		*a++ ^= *b++;
-	} while ((bs -= 4));
-}
-
-static void xor_64(u8 *a, const u8 *b, unsigned int bs)
-{
-	((u32 *)a)[0] ^= ((u32 *)b)[0];
-	((u32 *)a)[1] ^= ((u32 *)b)[1];
-}
-
-static void xor_128(u8 *a, const u8 *b, unsigned int bs)
-{
-	((u32 *)a)[0] ^= ((u32 *)b)[0];
-	((u32 *)a)[1] ^= ((u32 *)b)[1];
-	((u32 *)a)[2] ^= ((u32 *)b)[2];
-	((u32 *)a)[3] ^= ((u32 *)b)[3];
-}
-
 static int crypto_pcbc_init_tfm(struct crypto_tfm *tfm)
 {
 	struct crypto_instance *inst = (void *)tfm->__crt_alg;
@@ -249,22 +207,6 @@
 	struct crypto_pcbc_ctx *ctx = crypto_tfm_ctx(tfm);
 	struct crypto_cipher *cipher;
  
-	switch (crypto_tfm_alg_blocksize(tfm)) {
-	case 8:
-		ctx->xor = xor_64;
-		break;
-
-	case 16:
-		ctx->xor = xor_128;
-		break;
-
-	default:
-		if (crypto_tfm_alg_blocksize(tfm) % 4)
-			ctx->xor = xor_byte;
-		else
-			ctx->xor = xor_quad;
-	}
-
 	cipher = crypto_spawn_cipher(spawn);
 	if (IS_ERR(cipher))
 		return PTR_ERR(cipher);
@@ -304,8 +246,9 @@
 	inst->alg.cra_alignmask = alg->cra_alignmask;
 	inst->alg.cra_type = &crypto_blkcipher_type;
  
-	if (!(alg->cra_blocksize % 4))
-		inst->alg.cra_alignmask |= 3;
+	/* We access the data as u32s when xoring. */
+	inst->alg.cra_alignmask |= __alignof__(u32) - 1;
+
 	inst->alg.cra_blkcipher.ivsize = alg->cra_blocksize;
 	inst->alg.cra_blkcipher.min_keysize = alg->cra_cipher.cia_min_keysize;
 	inst->alg.cra_blkcipher.max_keysize = alg->cra_cipher.cia_max_keysize;
...	...	@@ -24,7 +24,6 @@
24	24
25	25	struct crypto_pcbc_ctx {
26	26	struct crypto_cipher *child;
27		- void (xor)(u8 dst, const u8 *src, unsigned int bs);
28	27	};
29	28
30	29	static int crypto_pcbc_setkey(struct crypto_tfm parent, const u8 key,
...	...	@@ -45,9 +44,7 @@
45	44
46	45	static int crypto_pcbc_encrypt_segment(struct blkcipher_desc *desc,
47	46	struct blkcipher_walk *walk,
48		- struct crypto_cipher *tfm,
49		- void (xor)(u8 , const u8 *,
50		- unsigned int))
	47	+ struct crypto_cipher *tfm)
51	48	{
52	49	void (fn)(struct crypto_tfm , u8 , const u8 ) =
53	50	crypto_cipher_alg(tfm)->cia_encrypt;
54	51
...	...	@@ -58,10 +55,10 @@
58	55	u8 *iv = walk->iv;
59	56
60	57	do {
61		- xor(iv, src, bsize);
	58	+ crypto_xor(iv, src, bsize);
62	59	fn(crypto_cipher_tfm(tfm), dst, iv);
63	60	memcpy(iv, dst, bsize);
64		- xor(iv, src, bsize);
	61	+ crypto_xor(iv, src, bsize);
65	62
66	63	src += bsize;
67	64	dst += bsize;
...	...	@@ -72,9 +69,7 @@
72	69
73	70	static int crypto_pcbc_encrypt_inplace(struct blkcipher_desc *desc,
74	71	struct blkcipher_walk *walk,
75		- struct crypto_cipher *tfm,
76		- void (xor)(u8 , const u8 *,
77		- unsigned int))
	72	+ struct crypto_cipher *tfm)
78	73	{
79	74	void (fn)(struct crypto_tfm , u8 , const u8 ) =
80	75	crypto_cipher_alg(tfm)->cia_encrypt;
81	76
...	...	@@ -86,10 +81,10 @@
86	81
87	82	do {
88	83	memcpy(tmpbuf, src, bsize);
89		- xor(iv, tmpbuf, bsize);
	84	+ crypto_xor(iv, src, bsize);
90	85	fn(crypto_cipher_tfm(tfm), src, iv);
91		- memcpy(iv, src, bsize);
92		- xor(iv, tmpbuf, bsize);
	86	+ memcpy(iv, tmpbuf, bsize);
	87	+ crypto_xor(iv, src, bsize);
93	88
94	89	src += bsize;
95	90	} while ((nbytes -= bsize) >= bsize);
...	...	@@ -107,7 +102,6 @@
107	102	struct crypto_blkcipher *tfm = desc->tfm;
108	103	struct crypto_pcbc_ctx *ctx = crypto_blkcipher_ctx(tfm);
109	104	struct crypto_cipher *child = ctx->child;
110		- void (xor)(u8 , const u8 *, unsigned int bs) = ctx->xor;
111	105	int err;
112	106
113	107	blkcipher_walk_init(&walk, dst, src, nbytes);
114	108
...	...	@@ -115,11 +109,11 @@
115	109
116	110	while ((nbytes = walk.nbytes)) {
117	111	if (walk.src.virt.addr == walk.dst.virt.addr)
118		- nbytes = crypto_pcbc_encrypt_inplace(desc, &walk, child,
119		- xor);
	112	+ nbytes = crypto_pcbc_encrypt_inplace(desc, &walk,
	113	+ child);
120	114	else
121		- nbytes = crypto_pcbc_encrypt_segment(desc, &walk, child,
122		- xor);
	115	+ nbytes = crypto_pcbc_encrypt_segment(desc, &walk,
	116	+ child);
123	117	err = blkcipher_walk_done(desc, &walk, nbytes);
124	118	}
125	119
...	...	@@ -128,9 +122,7 @@
128	122
129	123	static int crypto_pcbc_decrypt_segment(struct blkcipher_desc *desc,
130	124	struct blkcipher_walk *walk,
131		- struct crypto_cipher *tfm,
132		- void (xor)(u8 , const u8 *,
133		- unsigned int))
	125	+ struct crypto_cipher *tfm)
134	126	{
135	127	void (fn)(struct crypto_tfm , u8 , const u8 ) =
136	128	crypto_cipher_alg(tfm)->cia_decrypt;
137	129
...	...	@@ -142,9 +134,9 @@
142	134
143	135	do {
144	136	fn(crypto_cipher_tfm(tfm), dst, src);
145		- xor(dst, iv, bsize);
	137	+ crypto_xor(dst, iv, bsize);
146	138	memcpy(iv, src, bsize);
147		- xor(iv, dst, bsize);
	139	+ crypto_xor(iv, dst, bsize);
148	140
149	141	src += bsize;
150	142	dst += bsize;
...	...	@@ -157,9 +149,7 @@
157	149
158	150	static int crypto_pcbc_decrypt_inplace(struct blkcipher_desc *desc,
159	151	struct blkcipher_walk *walk,
160		- struct crypto_cipher *tfm,
161		- void (xor)(u8 , const u8 *,
162		- unsigned int))
	152	+ struct crypto_cipher *tfm)
163	153	{
164	154	void (fn)(struct crypto_tfm , u8 , const u8 ) =
165	155	crypto_cipher_alg(tfm)->cia_decrypt;
166	156
...	...	@@ -172,9 +162,9 @@
172	162	do {
173	163	memcpy(tmpbuf, src, bsize);
174	164	fn(crypto_cipher_tfm(tfm), src, src);
175		- xor(src, iv, bsize);
	165	+ crypto_xor(src, iv, bsize);
176	166	memcpy(iv, tmpbuf, bsize);
177		- xor(iv, src, bsize);
	167	+ crypto_xor(iv, src, bsize);
178	168
179	169	src += bsize;
180	170	} while ((nbytes -= bsize) >= bsize);
...	...	@@ -192,7 +182,6 @@
192	182	struct crypto_blkcipher *tfm = desc->tfm;
193	183	struct crypto_pcbc_ctx *ctx = crypto_blkcipher_ctx(tfm);
194	184	struct crypto_cipher *child = ctx->child;
195		- void (xor)(u8 , const u8 *, unsigned int bs) = ctx->xor;
196	185	int err;
197	186
198	187	blkcipher_walk_init(&walk, dst, src, nbytes);
199	188
200	189
...	...	@@ -200,48 +189,17 @@
200	189
201	190	while ((nbytes = walk.nbytes)) {
202	191	if (walk.src.virt.addr == walk.dst.virt.addr)
203		- nbytes = crypto_pcbc_decrypt_inplace(desc, &walk, child,
204		- xor);
	192	+ nbytes = crypto_pcbc_decrypt_inplace(desc, &walk,
	193	+ child);
205	194	else
206		- nbytes = crypto_pcbc_decrypt_segment(desc, &walk, child,
207		- xor);
	195	+ nbytes = crypto_pcbc_decrypt_segment(desc, &walk,
	196	+ child);
208	197	err = blkcipher_walk_done(desc, &walk, nbytes);
209	198	}
210	199
211	200	return err;
212	201	}
213	202
214		-static void xor_byte(u8 a, const u8 b, unsigned int bs)
215		-{
216		- do {
217		- a++ ^= b++;
218		- } while (--bs);
219		-}
220		-
221		-static void xor_quad(u8 dst, const u8 src, unsigned int bs)
222		-{
223		- u32 a = (u32 )dst;
224		- u32 b = (u32 )src;
225		-
226		- do {
227		- a++ ^= b++;
228		- } while ((bs -= 4));
229		-}
230		-
231		-static void xor_64(u8 a, const u8 b, unsigned int bs)
232		-{
233		- ((u32 )a)[0] ^= ((u32 )b)[0];
234		- ((u32 )a)[1] ^= ((u32 )b)[1];
235		-}
236		-
237		-static void xor_128(u8 a, const u8 b, unsigned int bs)
238		-{
239		- ((u32 )a)[0] ^= ((u32 )b)[0];
240		- ((u32 )a)[1] ^= ((u32 )b)[1];
241		- ((u32 )a)[2] ^= ((u32 )b)[2];
242		- ((u32 )a)[3] ^= ((u32 )b)[3];
243		-}
244		-
245	203	static int crypto_pcbc_init_tfm(struct crypto_tfm *tfm)
246	204	{
247	205	struct crypto_instance inst = (void )tfm->__crt_alg;
...	...	@@ -249,22 +207,6 @@
249	207	struct crypto_pcbc_ctx *ctx = crypto_tfm_ctx(tfm);
250	208	struct crypto_cipher *cipher;
251	209
252		- switch (crypto_tfm_alg_blocksize(tfm)) {
253		- case 8:
254		- ctx->xor = xor_64;
255		- break;
256		-
257		- case 16:
258		- ctx->xor = xor_128;
259		- break;
260		-
261		- default:
262		- if (crypto_tfm_alg_blocksize(tfm) % 4)
263		- ctx->xor = xor_byte;
264		- else
265		- ctx->xor = xor_quad;
266		- }
267		-
268	210	cipher = crypto_spawn_cipher(spawn);
269	211	if (IS_ERR(cipher))
270	212	return PTR_ERR(cipher);
...	...	@@ -304,8 +246,9 @@
304	246	inst->alg.cra_alignmask = alg->cra_alignmask;
305	247	inst->alg.cra_type = &crypto_blkcipher_type;
306	248
307		- if (!(alg->cra_blocksize % 4))
308		- inst->alg.cra_alignmask \|= 3;
	249	+ /* We access the data as u32s when xoring. */
	250	+ inst->alg.cra_alignmask \|= __alignof__(u32) - 1;
	251	+
309	252	inst->alg.cra_blkcipher.ivsize = alg->cra_blocksize;
310	253	inst->alg.cra_blkcipher.min_keysize = alg->cra_cipher.cia_min_keysize;
311	254	inst->alg.cra_blkcipher.max_keysize = alg->cra_cipher.cia_max_keysize;