[CRYPTO] cts: Add CTS mode required for Kerberos AES support

Implement CTS wrapper for CBC mode required for support of AES
encryption support for Kerberos (rfc3962).
Signed-off-by: Kevin Coffman <kwc@citi.umich.edu>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/Kconfig

@@ -213,6 +213,17 @@ config CRYPTO_CTR
 	  CTR: Counter mode
 	  This block cipher algorithm is required for IPSec.
 
+config CRYPTO_CTS
+	tristate "CTS support"
+	select CRYPTO_BLKCIPHER
+	help
+	  CTS: Cipher Text Stealing
+	  This is the Cipher Text Stealing mode as described by
+	  Section 8 of rfc2040 and referenced by rfc3962.
+	  (rfc3962 includes errata information in its Appendix A)
+	  This mode is required for Kerberos gss mechanism support
+	  for AES encryption.
+
 config CRYPTO_GCM
 	tristate "GCM/GMAC support"
 	select CRYPTO_CTR

crypto/Makefile

@@ -35,6 +35,7 @@ obj-$(CONFIG_CRYPTO_GF128MUL) += gf128mul.o
 obj-$(CONFIG_CRYPTO_ECB) += ecb.o
 obj-$(CONFIG_CRYPTO_CBC) += cbc.o
 obj-$(CONFIG_CRYPTO_PCBC) += pcbc.o
+obj-$(CONFIG_CRYPTO_CTS) += cts.o
 obj-$(CONFIG_CRYPTO_LRW) += lrw.o
 obj-$(CONFIG_CRYPTO_XTS) += xts.o
 obj-$(CONFIG_CRYPTO_CTR) += ctr.o

crypto/tcrypt.c

@@ -82,9 +82,8 @@ static char *check[] = {
 	"des", "md5", "des3_ede", "rot13", "sha1", "sha224", "sha256",
 	"blowfish", "twofish", "serpent", "sha384", "sha512", "md4", "aes",
 	"cast6", "arc4", "michael_mic", "deflate", "crc32c", "tea", "xtea",
-	"arc4", "michael_mic", "deflate", "crc32c", "tea", "xtea",
 	"khazad", "wp512", "wp384", "wp256", "tnepres", "xeta",  "fcrypt",
-	"camellia", "seed", "salsa20", "lzo", NULL
+	"camellia", "seed", "salsa20", "lzo", "cts", NULL
 };
 
 static void hexdump(unsigned char *buf, unsigned int len)
@@ -1328,6 +1327,12 @@ static void do_test(void)
 		test_cipher("ecb(seed)", DECRYPT, seed_dec_tv_template,
 			    SEED_DEC_TEST_VECTORS);
 
+		//CTS
+		test_cipher("cts(cbc(aes))", ENCRYPT, cts_mode_enc_tv_template,
+			    CTS_MODE_ENC_TEST_VECTORS);
+		test_cipher("cts(cbc(aes))", DECRYPT, cts_mode_dec_tv_template,
+			    CTS_MODE_DEC_TEST_VECTORS);
+
 		test_hash("sha384", sha384_tv_template, SHA384_TEST_VECTORS);
 		test_hash("sha512", sha512_tv_template, SHA512_TEST_VECTORS);
 		test_hash("wp512", wp512_tv_template, WP512_TEST_VECTORS);
@@ -1611,6 +1616,13 @@ static void do_test(void)
 			  AES_CCM_DEC_TEST_VECTORS);
 		break;
 
+	case 38:
+		test_cipher("cts(cbc(aes))", ENCRYPT, cts_mode_enc_tv_template,
+			    CTS_MODE_ENC_TEST_VECTORS);
+		test_cipher("cts(cbc(aes))", DECRYPT, cts_mode_dec_tv_template,
+			    CTS_MODE_DEC_TEST_VECTORS);
+		break;
+
 	case 100:
 		test_hash("hmac(md5)", hmac_md5_tv_template,
 			  HMAC_MD5_TEST_VECTORS);

crypto/tcrypt.h

@@ -7622,6 +7622,215 @@ static struct cipher_testvec salsa20_stream_enc_tv_template[] = {
 	},
 };
 
+/*
+ * CTS (Cipher Text Stealing) mode tests
+ */
+#define CTS_MODE_ENC_TEST_VECTORS 6
+#define CTS_MODE_DEC_TEST_VECTORS 6
+static struct cipher_testvec cts_mode_enc_tv_template[] = {
+	{ /* from rfc3962 */
+		.klen	= 16,
+		.key    = "\x63\x68\x69\x63\x6b\x65\x6e\x20"
+			  "\x74\x65\x72\x69\x79\x61\x6b\x69",
+		.ilen	= 17,
+		.input  = "\x49\x20\x77\x6f\x75\x6c\x64\x20"
+			  "\x6c\x69\x6b\x65\x20\x74\x68\x65"
+			  "\x20",
+		.rlen	= 17,
+		.result	= "\xc6\x35\x35\x68\xf2\xbf\x8c\xb4"
+			  "\xd8\xa5\x80\x36\x2d\xa7\xff\x7f"
+			  "\x97",
+	}, {
+		.klen	= 16,
+		.key    = "\x63\x68\x69\x63\x6b\x65\x6e\x20"
+			  "\x74\x65\x72\x69\x79\x61\x6b\x69",
+		.ilen   = 31,
+		.input  = "\x49\x20\x77\x6f\x75\x6c\x64\x20"
+			  "\x6c\x69\x6b\x65\x20\x74\x68\x65"
+			  "\x20\x47\x65\x6e\x65\x72\x61\x6c"
+			  "\x20\x47\x61\x75\x27\x73\x20",
+		.rlen   = 31,
+		.result = "\xfc\x00\x78\x3e\x0e\xfd\xb2\xc1"
+			  "\xd4\x45\xd4\xc8\xef\xf7\xed\x22"
+			  "\x97\x68\x72\x68\xd6\xec\xcc\xc0"
+			  "\xc0\x7b\x25\xe2\x5e\xcf\xe5",
+	}, {
+		.klen	= 16,
+		.key    = "\x63\x68\x69\x63\x6b\x65\x6e\x20"
+			  "\x74\x65\x72\x69\x79\x61\x6b\x69",
+		.ilen   = 32,
+		.input  = "\x49\x20\x77\x6f\x75\x6c\x64\x20"
+			  "\x6c\x69\x6b\x65\x20\x74\x68\x65"
+			  "\x20\x47\x65\x6e\x65\x72\x61\x6c"
+			  "\x20\x47\x61\x75\x27\x73\x20\x43",
+		.rlen   = 32,
+		.result = "\x39\x31\x25\x23\xa7\x86\x62\xd5"
+			  "\xbe\x7f\xcb\xcc\x98\xeb\xf5\xa8"
+			  "\x97\x68\x72\x68\xd6\xec\xcc\xc0"
+			  "\xc0\x7b\x25\xe2\x5e\xcf\xe5\x84",
+	}, {
+		.klen	= 16,
+		.key    = "\x63\x68\x69\x63\x6b\x65\x6e\x20"
+			  "\x74\x65\x72\x69\x79\x61\x6b\x69",
+		.ilen   = 47,
+		.input  = "\x49\x20\x77\x6f\x75\x6c\x64\x20"
+			  "\x6c\x69\x6b\x65\x20\x74\x68\x65"
+			  "\x20\x47\x65\x6e\x65\x72\x61\x6c"
+			  "\x20\x47\x61\x75\x27\x73\x20\x43"
+			  "\x68\x69\x63\x6b\x65\x6e\x2c\x20"
+			  "\x70\x6c\x65\x61\x73\x65\x2c",
+		.rlen   = 47,
+		.result = "\x97\x68\x72\x68\xd6\xec\xcc\xc0"
+			  "\xc0\x7b\x25\xe2\x5e\xcf\xe5\x84"
+			  "\xb3\xff\xfd\x94\x0c\x16\xa1\x8c"
+			  "\x1b\x55\x49\xd2\xf8\x38\x02\x9e"
+			  "\x39\x31\x25\x23\xa7\x86\x62\xd5"
+			  "\xbe\x7f\xcb\xcc\x98\xeb\xf5",
+	}, {
+		.klen	= 16,
+		.key    = "\x63\x68\x69\x63\x6b\x65\x6e\x20"
+			  "\x74\x65\x72\x69\x79\x61\x6b\x69",
+		.ilen   = 48,
+		.input  = "\x49\x20\x77\x6f\x75\x6c\x64\x20"
+			  "\x6c\x69\x6b\x65\x20\x74\x68\x65"
+			  "\x20\x47\x65\x6e\x65\x72\x61\x6c"
+			  "\x20\x47\x61\x75\x27\x73\x20\x43"
+			  "\x68\x69\x63\x6b\x65\x6e\x2c\x20"
+			  "\x70\x6c\x65\x61\x73\x65\x2c\x20",
+		.rlen   = 48,
+		.result = "\x97\x68\x72\x68\xd6\xec\xcc\xc0"
+			  "\xc0\x7b\x25\xe2\x5e\xcf\xe5\x84"
+			  "\x9d\xad\x8b\xbb\x96\xc4\xcd\xc0"
+			  "\x3b\xc1\x03\xe1\xa1\x94\xbb\xd8"
+			  "\x39\x31\x25\x23\xa7\x86\x62\xd5"
+			  "\xbe\x7f\xcb\xcc\x98\xeb\xf5\xa8",
+	}, {
+		.klen	= 16,
+		.key    = "\x63\x68\x69\x63\x6b\x65\x6e\x20"
+			  "\x74\x65\x72\x69\x79\x61\x6b\x69",
+		.ilen   = 64,
+		.input  = "\x49\x20\x77\x6f\x75\x6c\x64\x20"
+			  "\x6c\x69\x6b\x65\x20\x74\x68\x65"
+			  "\x20\x47\x65\x6e\x65\x72\x61\x6c"
+			  "\x20\x47\x61\x75\x27\x73\x20\x43"
+			  "\x68\x69\x63\x6b\x65\x6e\x2c\x20"
+			  "\x70\x6c\x65\x61\x73\x65\x2c\x20"
+			  "\x61\x6e\x64\x20\x77\x6f\x6e\x74"
+			  "\x6f\x6e\x20\x73\x6f\x75\x70\x2e",
+		.rlen   = 64,
+		.result = "\x97\x68\x72\x68\xd6\xec\xcc\xc0"
+			  "\xc0\x7b\x25\xe2\x5e\xcf\xe5\x84"
+			  "\x39\x31\x25\x23\xa7\x86\x62\xd5"
+			  "\xbe\x7f\xcb\xcc\x98\xeb\xf5\xa8"
+			  "\x48\x07\xef\xe8\x36\xee\x89\xa5"
+			  "\x26\x73\x0d\xbc\x2f\x7b\xc8\x40"
+			  "\x9d\xad\x8b\xbb\x96\xc4\xcd\xc0"
+			  "\x3b\xc1\x03\xe1\xa1\x94\xbb\xd8",
+	}
+};
+
+static struct cipher_testvec cts_mode_dec_tv_template[] = {
+	{ /* from rfc3962 */
+		.klen	= 16,
+		.key    = "\x63\x68\x69\x63\x6b\x65\x6e\x20"
+			  "\x74\x65\x72\x69\x79\x61\x6b\x69",
+		.rlen	= 17,
+		.result = "\x49\x20\x77\x6f\x75\x6c\x64\x20"
+			  "\x6c\x69\x6b\x65\x20\x74\x68\x65"
+			  "\x20",
+		.ilen	= 17,
+		.input	= "\xc6\x35\x35\x68\xf2\xbf\x8c\xb4"
+			  "\xd8\xa5\x80\x36\x2d\xa7\xff\x7f"
+			  "\x97",
+	}, {
+		.klen	= 16,
+		.key    = "\x63\x68\x69\x63\x6b\x65\x6e\x20"
+			  "\x74\x65\x72\x69\x79\x61\x6b\x69",
+		.rlen   = 31,
+		.result = "\x49\x20\x77\x6f\x75\x6c\x64\x20"
+			  "\x6c\x69\x6b\x65\x20\x74\x68\x65"
+			  "\x20\x47\x65\x6e\x65\x72\x61\x6c"
+			  "\x20\x47\x61\x75\x27\x73\x20",
+		.ilen   = 31,
+		.input  = "\xfc\x00\x78\x3e\x0e\xfd\xb2\xc1"
+			  "\xd4\x45\xd4\xc8\xef\xf7\xed\x22"
+			  "\x97\x68\x72\x68\xd6\xec\xcc\xc0"
+			  "\xc0\x7b\x25\xe2\x5e\xcf\xe5",
+	}, {
+		.klen	= 16,
+		.key    = "\x63\x68\x69\x63\x6b\x65\x6e\x20"
+			  "\x74\x65\x72\x69\x79\x61\x6b\x69",
+		.rlen   = 32,
+		.result = "\x49\x20\x77\x6f\x75\x6c\x64\x20"
+			  "\x6c\x69\x6b\x65\x20\x74\x68\x65"
+			  "\x20\x47\x65\x6e\x65\x72\x61\x6c"
+			  "\x20\x47\x61\x75\x27\x73\x20\x43",
+		.ilen   = 32,
+		.input  = "\x39\x31\x25\x23\xa7\x86\x62\xd5"
+			  "\xbe\x7f\xcb\xcc\x98\xeb\xf5\xa8"
+			  "\x97\x68\x72\x68\xd6\xec\xcc\xc0"
+			  "\xc0\x7b\x25\xe2\x5e\xcf\xe5\x84",
+	}, {
+		.klen	= 16,
+		.key    = "\x63\x68\x69\x63\x6b\x65\x6e\x20"
+			  "\x74\x65\x72\x69\x79\x61\x6b\x69",
+		.rlen   = 47,
+		.result = "\x49\x20\x77\x6f\x75\x6c\x64\x20"
+			  "\x6c\x69\x6b\x65\x20\x74\x68\x65"
+			  "\x20\x47\x65\x6e\x65\x72\x61\x6c"
+			  "\x20\x47\x61\x75\x27\x73\x20\x43"
+			  "\x68\x69\x63\x6b\x65\x6e\x2c\x20"
+			  "\x70\x6c\x65\x61\x73\x65\x2c",
+		.ilen   = 47,
+		.input  = "\x97\x68\x72\x68\xd6\xec\xcc\xc0"
+			  "\xc0\x7b\x25\xe2\x5e\xcf\xe5\x84"
+			  "\xb3\xff\xfd\x94\x0c\x16\xa1\x8c"
+			  "\x1b\x55\x49\xd2\xf8\x38\x02\x9e"
+			  "\x39\x31\x25\x23\xa7\x86\x62\xd5"
+			  "\xbe\x7f\xcb\xcc\x98\xeb\xf5",
+	}, {
+		.klen	= 16,
+		.key    = "\x63\x68\x69\x63\x6b\x65\x6e\x20"
+			  "\x74\x65\x72\x69\x79\x61\x6b\x69",
+		.rlen   = 48,
+		.result = "\x49\x20\x77\x6f\x75\x6c\x64\x20"
+			  "\x6c\x69\x6b\x65\x20\x74\x68\x65"
+			  "\x20\x47\x65\x6e\x65\x72\x61\x6c"
+			  "\x20\x47\x61\x75\x27\x73\x20\x43"
+			  "\x68\x69\x63\x6b\x65\x6e\x2c\x20"
+			  "\x70\x6c\x65\x61\x73\x65\x2c\x20",
+		.ilen   = 48,
+		.input  = "\x97\x68\x72\x68\xd6\xec\xcc\xc0"
+			  "\xc0\x7b\x25\xe2\x5e\xcf\xe5\x84"
+			  "\x9d\xad\x8b\xbb\x96\xc4\xcd\xc0"
+			  "\x3b\xc1\x03\xe1\xa1\x94\xbb\xd8"
+			  "\x39\x31\x25\x23\xa7\x86\x62\xd5"
+			  "\xbe\x7f\xcb\xcc\x98\xeb\xf5\xa8",
+	}, {
+		.klen	= 16,
+		.key    = "\x63\x68\x69\x63\x6b\x65\x6e\x20"
+			  "\x74\x65\x72\x69\x79\x61\x6b\x69",
+		.rlen   = 64,
+		.result = "\x49\x20\x77\x6f\x75\x6c\x64\x20"
+			  "\x6c\x69\x6b\x65\x20\x74\x68\x65"
+			  "\x20\x47\x65\x6e\x65\x72\x61\x6c"
+			  "\x20\x47\x61\x75\x27\x73\x20\x43"
+			  "\x68\x69\x63\x6b\x65\x6e\x2c\x20"
+			  "\x70\x6c\x65\x61\x73\x65\x2c\x20"
+			  "\x61\x6e\x64\x20\x77\x6f\x6e\x74"
+			  "\x6f\x6e\x20\x73\x6f\x75\x70\x2e",
+		.ilen   = 64,
+		.input  = "\x97\x68\x72\x68\xd6\xec\xcc\xc0"
+			  "\xc0\x7b\x25\xe2\x5e\xcf\xe5\x84"
+			  "\x39\x31\x25\x23\xa7\x86\x62\xd5"
+			  "\xbe\x7f\xcb\xcc\x98\xeb\xf5\xa8"
+			  "\x48\x07\xef\xe8\x36\xee\x89\xa5"
+			  "\x26\x73\x0d\xbc\x2f\x7b\xc8\x40"
+			  "\x9d\xad\x8b\xbb\x96\xc4\xcd\xc0"
+			  "\x3b\xc1\x03\xe1\xa1\x94\xbb\xd8",
+	}
+};
+
 /*
  * Compression stuff.
  */