Provisional AES XTS support.

CHANGES

@@ -4,6 +4,11 @@
 
  Changes between 1.0.1 and 1.1.0  [xx XXX xxxx]
 
+  *) Provisional XTS support. Note: this does increase the maximum key
+     length from 32 to 64 bytes but there should be no binary compatibility
+     issues as existing applications will never use XTS mode.
+     [Steve Henson]
+
   *) Extensive reorganisation of FIPS PRNG behaviour. Remove all dependencies
      to OpenSSL RAND code and replace with a tiny FIPS RAND API which also
      performs algorithm blocking for unapproved PRNG types. Also do not

crypto/evp/e_aes.c

@@ -458,5 +458,104 @@ static const EVP_CIPHER aes_256_gcm_cipher=
 
 const EVP_CIPHER *EVP_aes_256_gcm (void)
 {	return &aes_256_gcm_cipher;	}
+
+typedef struct
+	{
+	/* AES key schedules to use */
+	AES_KEY ks1, ks2;
+	XTS128_CONTEXT xts;
+	} EVP_AES_XTS_CTX;
+
+static int aes_xts_ctrl(EVP_CIPHER_CTX *c, int type, int arg, void *ptr)
+	{
+	EVP_AES_XTS_CTX *xctx = c->cipher_data;
+	if (type != EVP_CTRL_INIT)
+		return -1;
+	/* key1 and key2 are used as an indicator both key and IV are set */
+	xctx->xts.key1 = NULL;
+	xctx->xts.key2 = NULL;
+	xctx->xts.block1 = (block128_f)AES_encrypt;
+	xctx->xts.block2 = (block128_f)AES_encrypt;
+	return 1;
+	}
+
+static int aes_xts_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
+                        const unsigned char *iv, int enc)
+	{
+	EVP_AES_XTS_CTX *xctx = ctx->cipher_data;
+	if (!iv && !key)
+		return 1;
+
+	if (key)
+		{
+		AES_set_encrypt_key(key, ctx->key_len * 8, &xctx->ks1);
+		AES_set_encrypt_key(key + ctx->key_len, ctx->key_len * 8,
+								&xctx->ks2);
+
+		xctx->xts.key1 = &xctx->ks1;
+		xctx->xts.block1 = (block128_f)AES_encrypt;
+		xctx->xts.block2 = (block128_f)AES_encrypt;
+		}
+
+	if (iv)
+		{
+		xctx->xts.key2 = &xctx->ks2;
+		memcpy(ctx->iv, iv, 16);
+		}
+
+	return 1;
+	}
+
+static int aes_xts(EVP_CIPHER_CTX *ctx, unsigned char *out,
+		const unsigned char *in, size_t len)
+	{
+	EVP_AES_XTS_CTX *xctx = ctx->cipher_data;
+	if (!xctx->xts.key1 || !xctx->xts.key2)
+		return -1;
+	if (!out || !in)
+		return -1;
+	if (CRYPTO_xts128_encrypt(&xctx->xts, ctx->iv, in, out, len,
+								ctx->encrypt))
+		return -1;
+	return len;
+	}
+
+static const EVP_CIPHER aes_128_xts_cipher=
+	{
+	NID_aes_128_xts,16,32,16,
+	EVP_CIPH_XTS_MODE|EVP_CIPH_FLAG_FIPS|EVP_CIPH_FLAG_DEFAULT_ASN1
+		| EVP_CIPH_CUSTOM_IV | EVP_CIPH_FLAG_CUSTOM_CIPHER
+		| EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CTRL_INIT,
+	aes_xts_init_key,
+	aes_xts,
+	0,
+	sizeof(EVP_AES_XTS_CTX),
+	NULL,
+	NULL,
+	aes_xts_ctrl,
+	NULL
+	};
+
+const EVP_CIPHER *EVP_aes_128_xts (void)
+{	return &aes_128_xts_cipher;	}
+	
+static const EVP_CIPHER aes_256_xts_cipher=
+	{
+	NID_aes_256_xts,16,64,16,
+	EVP_CIPH_XTS_MODE|EVP_CIPH_FLAG_FIPS|EVP_CIPH_FLAG_DEFAULT_ASN1
+		| EVP_CIPH_CUSTOM_IV | EVP_CIPH_FLAG_CUSTOM_CIPHER
+		| EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CTRL_INIT,
+	aes_xts_init_key,
+	aes_xts,
+	0,
+	sizeof(EVP_AES_XTS_CTX),
+	NULL,
+	NULL,
+	aes_xts_ctrl,
+	NULL
+	};
+
+const EVP_CIPHER *EVP_aes_256_xts (void)
+{	return &aes_256_xts_cipher;	}
 		
 #endif

crypto/evp/evp.h

@@ -83,7 +83,7 @@
 #define EVP_RC5_32_12_16_KEY_SIZE	16
 */
 #define EVP_MAX_MD_SIZE			64	/* longest known is SHA512 */
-#define EVP_MAX_KEY_LENGTH		32
+#define EVP_MAX_KEY_LENGTH		64
 #define EVP_MAX_IV_LENGTH		16
 #define EVP_MAX_BLOCK_LENGTH		32
 
@@ -330,6 +330,8 @@ struct evp_cipher_st
 #define		EVP_CIPH_OFB_MODE		0x4
 #define		EVP_CIPH_CTR_MODE		0x5
 #define		EVP_CIPH_GCM_MODE		0x6
+#define		EVP_CIPH_CCM_MODE		0x7
+#define		EVP_CIPH_XTS_MODE		0x10001
 #define 	EVP_CIPH_MODE			0xF0007
 /* Set if variable length cipher */
 #define 	EVP_CIPH_VARIABLE_LENGTH	0x8
@@ -788,6 +790,7 @@ const EVP_CIPHER *EVP_aes_128_cfb128(void);
 const EVP_CIPHER *EVP_aes_128_ofb(void);
 const EVP_CIPHER *EVP_aes_128_ctr(void);
 const EVP_CIPHER *EVP_aes_128_gcm(void);
+const EVP_CIPHER *EVP_aes_128_xts(void);
 const EVP_CIPHER *EVP_aes_192_ecb(void);
 const EVP_CIPHER *EVP_aes_192_cbc(void);
 const EVP_CIPHER *EVP_aes_192_cfb1(void);
@@ -806,6 +809,7 @@ const EVP_CIPHER *EVP_aes_256_cfb128(void);
 const EVP_CIPHER *EVP_aes_256_ofb(void);
 const EVP_CIPHER *EVP_aes_256_ctr(void);
 const EVP_CIPHER *EVP_aes_256_gcm(void);
+const EVP_CIPHER *EVP_aes_256_xts(void);
 #endif
 #ifndef OPENSSL_NO_CAMELLIA
 const EVP_CIPHER *EVP_camellia_128_ecb(void);

crypto/modes/Makefile

@@ -21,9 +21,9 @@ TEST=
 APPS=
 
 LIB=$(TOP)/libcrypto.a
-LIBSRC= cbc128.c ctr128.c cts128.c cfb128.c ofb128.c gcm128.c
+LIBSRC= cbc128.c ctr128.c cts128.c cfb128.c ofb128.c gcm128.c xts128.c
 LIBOBJ= cbc128.o ctr128.o cts128.o cfb128.o ofb128.o gcm128.o \
-	$(MODES_ASM_OBJ)
+	xts128.o $(MODES_ASM_OBJ)
 
 SRC= $(LIBSRC)
 

crypto/modes/modes.h

@@ -104,3 +104,9 @@ int  CRYPTO_gcm128_finish(GCM128_CONTEXT *ctx,const unsigned char *tag,
 			size_t len);
 void  CRYPTO_gcm128_tag(GCM128_CONTEXT *ctx, unsigned char *tag, size_t len);
 void CRYPTO_gcm128_release(GCM128_CONTEXT *ctx);
+
+typedef struct xts128_context XTS128_CONTEXT;
+
+int CRYPTO_xts128_encrypt(const XTS128_CONTEXT *ctx, const unsigned char *iv,
+	const unsigned char *inp, unsigned char *out,
+	size_t len, int enc);

crypto/modes/modes_lcl.h

@@ -116,3 +116,9 @@ struct gcm128_context {
 	block128_f block;
 	void *key;
 };
+
+struct xts128_context {
+	void      *key1, *key2;
+	block128_f block1,block2;
+};
+

crypto/modes/xts128.c

@@ -58,12 +58,7 @@
 #endif
 #include <assert.h>
 
-typedef struct {
+int CRYPTO_xts128_encrypt(const XTS128_CONTEXT *ctx, const unsigned char *iv,
-	void      *key1, *key2;
-	block128_f block1,block2;
-} XTS128_CONTEXT;
-
-int CRYPTO_xts128_encrypt(const XTS128_CONTEXT *ctx, u64 secno,
 	const unsigned char *inp, unsigned char *out,
 	size_t len, int enc)
 {
@@ -73,15 +68,7 @@ int CRYPTO_xts128_encrypt(const XTS128_CONTEXT *ctx, u64 secno,
 
 	if (len<16) return -1;
 
-	if (is_endian.little) {
+	memcpy(tweak.c, iv, 16);
-		tweak.u[0] = secno;
-		tweak.u[1] = 0;
-	}
-	else {
-		PUTU32(tweak.c,secno);
-		PUTU32(tweak.c+4,secno>>32);
-		tweak.u[1] = 0;
-	}
 
 	(*ctx->block2)(tweak.c,tweak.c,ctx->key2);
 

crypto/objects/obj_dat.h

@@ -62,9 +62,9 @@
  * [including the GNU Public Licence.]
  */
 
-#define NUM_NID 913
+#define NUM_NID 915
-#define NUM_SN 906
+#define NUM_SN 908
-#define NUM_LN 906
+#define NUM_LN 908
 #define NUM_OBJ 856
 
 static const unsigned char lvalues[5971]={
@@ -2395,6 +2395,8 @@ static const ASN1_OBJECT nid_objs[NUM_NID]={
 	NID_anyExtendedKeyUsage,4,&(lvalues[5948]),0},
 {"MGF1","mgf1",NID_mgf1,9,&(lvalues[5952]),0},
 {"RSASSA-PSS","rsassaPss",NID_rsassaPss,9,&(lvalues[5961]),0},
+{"AES-128-XTS","aes-128-xts",NID_aes_128_xts,0,NULL,0},
+{"AES-256-XTS","aes-256-xts",NID_aes_256_xts,0,NULL,0},
 };
 
 static const unsigned int sn_objs[NUM_SN]={
@@ -2406,6 +2408,7 @@ static const unsigned int sn_objs[NUM_SN]={
 904,	/* "AES-128-CTR" */
 418,	/* "AES-128-ECB" */
 420,	/* "AES-128-OFB" */
+913,	/* "AES-128-XTS" */
 423,	/* "AES-192-CBC" */
 425,	/* "AES-192-CFB" */
 651,	/* "AES-192-CFB1" */
@@ -2420,6 +2423,7 @@ static const unsigned int sn_objs[NUM_SN]={
 906,	/* "AES-256-CTR" */
 426,	/* "AES-256-ECB" */
 428,	/* "AES-256-OFB" */
+914,	/* "AES-256-XTS" */
 91,	/* "BF-CBC" */
 93,	/* "BF-CFB" */
 92,	/* "BF-ECB" */
@@ -3459,6 +3463,7 @@ static const unsigned int ln_objs[NUM_LN]={
 418,	/* "aes-128-ecb" */
 895,	/* "aes-128-gcm" */
 420,	/* "aes-128-ofb" */
+913,	/* "aes-128-xts" */
 423,	/* "aes-192-cbc" */
 899,	/* "aes-192-ccm" */
 425,	/* "aes-192-cfb" */
@@ -3477,6 +3482,7 @@ static const unsigned int ln_objs[NUM_LN]={
 426,	/* "aes-256-ecb" */
 901,	/* "aes-256-gcm" */
 428,	/* "aes-256-ofb" */
+914,	/* "aes-256-xts" */
 376,	/* "algorithm" */
 484,	/* "associatedDomain" */
 485,	/* "associatedName" */

crypto/objects/obj_mac.h

@@ -2735,6 +2735,14 @@
 #define LN_aes_256_ctr		"aes-256-ctr"
 #define NID_aes_256_ctr		906
 
+#define SN_aes_128_xts		"AES-128-XTS"
+#define LN_aes_128_xts		"aes-128-xts"
+#define NID_aes_128_xts		913
+
+#define SN_aes_256_xts		"AES-256-XTS"
+#define LN_aes_256_xts		"aes-256-xts"
+#define NID_aes_256_xts		914
+
 #define SN_des_cfb1		"DES-CFB1"
 #define LN_des_cfb1		"des-cfb1"
 #define NID_des_cfb1		656

crypto/objects/obj_mac.num

@@ -910,3 +910,5 @@ id_camellia256_wrap		909
 anyExtendedKeyUsage		910
 mgf1		911
 rsassaPss		912
+aes_128_xts		913
+aes_256_xts		914

crypto/objects/objects.txt

@@ -892,6 +892,8 @@ aes 48			: id-aes256-wrap-pad
 			: AES-128-CTR		: aes-128-ctr
 			: AES-192-CTR		: aes-192-ctr
 			: AES-256-CTR		: aes-256-ctr
+			: AES-128-XTS		: aes-128-xts
+			: AES-256-XTS		: aes-256-xts
 			: DES-CFB1		: des-cfb1
 			: DES-CFB8		: des-cfb8
 			: DES-EDE3-CFB1		: des-ede3-cfb1