[CRYPTO]: Add ARC4 module.

Documentation/crypto/api-intro.txt

@@ -186,6 +186,7 @@ Original developers of the crypto algorithms:
   Dag Arne Osvik (Serpent)
   Brian Gladman (AES)
   Kartikey Mahendra Bhatt (CAST6)
+  Jon Oberheide (ARC4)
 
 SHA1 algorithm contributors:
   Jean-Francois Dive

crypto/Kconfig

@@ -140,6 +140,16 @@ config CRYPTO_CAST6
 	  The CAST6 encryption algorithm (synonymous with CAST-256) is
 	  described in RFC2612.
 
+config CRYPTO_ARC4
+	tristate "ARC4 cipher algorithm"
+	depends on CRYPTO
+	help
+	  ARC4 cipher algorithm.
+
+	  This is a stream cipher using keys ranging from 8 bits to 2048
+	  bits in length.  ARC4 is commonly used in protocols such as WEP 
+	  and SSL.
+
 config CRYPTO_DEFLATE
 	tristate "Deflate compression algorithm"
 	depends on CRYPTO

crypto/Makefile

@@ -21,6 +21,7 @@ obj-$(CONFIG_CRYPTO_SERPENT) += serpent.o
 obj-$(CONFIG_CRYPTO_AES) += aes.o
 obj-$(CONFIG_CRYPTO_CAST5) += cast5.o
 obj-$(CONFIG_CRYPTO_CAST6) += cast6.o
+obj-$(CONFIG_CRYPTO_ARC4) += arc4.o
 obj-$(CONFIG_CRYPTO_DEFLATE) += deflate.o
 
 obj-$(CONFIG_CRYPTO_TEST) += tcrypt.o

crypto/arc4.c

+/* 
+ * Cryptographic API
+ *
+ * ARC4 Cipher Algorithm
+ *
+ * Jon Oberheide <jon@focalhost.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/crypto.h>
+
+#define ARC4_MIN_KEY_SIZE	1
+#define ARC4_MAX_KEY_SIZE	256
+#define ARC4_BLOCK_SIZE		1
+
+struct arc4_ctx {
+	u8 S[256];
+	u8 x, y;
+};
+
+static int arc4_set_key(void *ctx_arg, const u8 *in_key, unsigned int key_len, u32 *flags)
+{
+	struct arc4_ctx *ctx = ctx_arg;
+	int i, j = 0, k = 0;
+
+	ctx->x = 1;
+	ctx->y = 0;
+
+	for(i = 0; i < 256; i++)
+		ctx->S[i] = i;
+
+	for(i = 0; i < 256; i++)
+	{
+		u8 a = ctx->S[i];
+		j = (j + in_key[k] + a) & 0xff;
+		ctx->S[i] = ctx->S[j];
+		ctx->S[j] = a;
+		if(++k >= key_len)
+			k = 0;
+	}
+
+	/* TODO: dump the first 768 bytes generated as recommended
+	   by Ilya Mironov (http://eprint.iacr.org/2002/067/) to 
+	   increase the statistical strength of the state table */
+
+	return 0;
+}
+
+static void arc4_crypt(void *ctx_arg, u8 *out, const u8 *in)
+{
+	struct arc4_ctx *ctx = ctx_arg;
+
+	u8 *const S = ctx->S;
+	u8 x = ctx->x;
+	u8 y = ctx->y;
+
+	u8 a = S[x];
+	y = (y + a) & 0xff;
+	u8 b = S[y];
+	S[x] = b;
+	S[y] = a;
+	x = (x + 1) & 0xff;
+	*out++ = *in ^ S[(a + b) & 0xff];
+
+	ctx->x = x;
+	ctx->y = y;
+}
+
+static struct crypto_alg arc4_alg = {
+	.cra_name		=	"arc4",
+	.cra_flags		=	CRYPTO_ALG_TYPE_CIPHER,
+	.cra_blocksize		=	ARC4_BLOCK_SIZE,
+	.cra_ctxsize		=	sizeof(struct arc4_ctx),
+	.cra_module		=	THIS_MODULE,
+	.cra_list		=	LIST_HEAD_INIT(arc4_alg.cra_list),
+	.cra_u			=	{ .cipher = {
+	.cia_min_keysize	=	ARC4_MIN_KEY_SIZE,
+	.cia_max_keysize	=	ARC4_MAX_KEY_SIZE,
+	.cia_setkey	   	= 	arc4_set_key,
+	.cia_encrypt	 	=	arc4_crypt,
+	.cia_decrypt	  	=	arc4_crypt } }
+};
+
+static int __init arc4_init(void)
+{
+	return crypto_register_alg(&arc4_alg);
+}
+
+
+static void __exit arc4_exit(void)
+{
+	crypto_unregister_alg(&arc4_alg);
+}
+
+module_init(arc4_init);
+module_exit(arc4_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("ARC4 Cipher Algorithm");
+MODULE_AUTHOR("Jon Oberheide <jon@focalhost.com>");

crypto/tcrypt.c

@@ -61,7 +61,7 @@ static char *tvmem;
 static char *check[] = {
 	"des", "md5", "des3_ede", "rot13", "sha1", "sha256", "blowfish",
 	"twofish", "serpent", "sha384", "sha512", "md4", "aes", "cast6", 
-	"deflate", NULL
+	"arc4", "deflate", NULL
 };
 
 static void
@@ -556,6 +556,10 @@ do_test(void)
 		test_cipher ("cast6", MODE_ECB, ENCRYPT, cast6_enc_tv_template, CAST6_ENC_TEST_VECTORS);
 		test_cipher ("cast6", MODE_ECB, DECRYPT, cast6_dec_tv_template, CAST6_DEC_TEST_VECTORS);
 
+		//ARC4
+		test_cipher ("arc4", MODE_ECB, ENCRYPT, arc4_enc_tv_template, ARC4_ENC_TEST_VECTORS);
+		test_cipher ("arc4x", MODE_ECB, DECRYPT, arc4_dec_tv_template, ARC4_DEC_TEST_VECTORS);
+
 		test_hash("sha384", sha384_tv_template, SHA384_TEST_VECTORS);
 		test_hash("sha512", sha512_tv_template, SHA512_TEST_VECTORS);
 		test_deflate();		
@@ -638,6 +642,11 @@ do_test(void)
 		test_cipher ("cast6", MODE_ECB, DECRYPT, cast6_dec_tv_template, CAST6_DEC_TEST_VECTORS);
 		break;
 
+	case 16:
+		test_cipher ("arc4", MODE_ECB, ENCRYPT, arc4_enc_tv_template, ARC4_ENC_TEST_VECTORS);
+		test_cipher ("arc4", MODE_ECB, DECRYPT, arc4_dec_tv_template, ARC4_DEC_TEST_VECTORS);
+		break;
+
 #ifdef CONFIG_CRYPTO_HMAC
 	case 100:
 		test_hmac("md5", hmac_md5_tv_template, HMAC_MD5_TEST_VECTORS);

crypto/tcrypt.h

@@ -1488,6 +1488,147 @@ struct cipher_testvec cast5_dec_tv_template[] =
 	},
 };
 
+/* 
+ * ARC4 test vectors from OpenSSL 
+ */
+#define ARC4_ENC_TEST_VECTORS	7
+#define ARC4_DEC_TEST_VECTORS	7
+
+struct cipher_testvec arc4_enc_tv_template[] =
+{
+	{
+		.key	= { 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef },
+		.klen	= 8,
+		.input	= { 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef },
+		.ilen	= 8,
+		.result	= { 0x75, 0xb7, 0x87, 0x80, 0x99, 0xe0, 0xc5, 0x96 },
+		.rlen	= 8,
+	}, {
+		.key	= { 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef },
+		.klen	= 8,
+		.input	= { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
+		.ilen	= 8,
+		.result	= { 0x74, 0x94, 0xc2, 0xe7, 0x10, 0x4b, 0x08, 0x79 },
+		.rlen	= 8,
+	}, {
+		.key	= { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
+		.klen	= 8,
+		.input	= { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
+		.ilen	= 8,
+		.result	= { 0xde, 0x18, 0x89, 0x41, 0xa3, 0x37, 0x5d, 0x3a },
+		.rlen	= 8,
+	}, {
+		.key	= { 0xef, 0x01, 0x23, 0x45},
+		.klen	= 4,
+		.input	= { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			    0x00, 0x00, 0x00, 0x00 },
+		.ilen	= 20,
+		.result	= { 0xd6, 0xa1, 0x41, 0xa7, 0xec, 0x3c, 0x38, 0xdf,
+			    0xbd, 0x61, 0x5a, 0x11, 0x62, 0xe1, 0xc7, 0xba,
+			    0x36, 0xb6, 0x78, 0x58 },
+		.rlen	= 20,
+	}, {
+		.key	= { 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef },
+		.klen	= 8,
+		.input	= { 0x12, 0x34, 0x56, 0x78, 0x9A, 0xBC, 0xDE, 0xF0,
+			    0x12, 0x34, 0x56, 0x78, 0x9A, 0xBC, 0xDE, 0xF0,
+			    0x12, 0x34, 0x56, 0x78, 0x9A, 0xBC, 0xDE, 0xF0,
+			    0x12, 0x34, 0x56, 0x78 },
+		.ilen	= 28,
+		.result	= { 0x66, 0xa0, 0x94, 0x9f, 0x8a, 0xf7, 0xd6, 0x89,
+			    0x1f, 0x7f, 0x83, 0x2b, 0xa8, 0x33, 0xc0, 0x0c,
+			    0x89, 0x2e, 0xbe, 0x30, 0x14, 0x3c, 0xe2, 0x87,
+			    0x40, 0x01, 0x1e, 0xcf },
+		.rlen	= 28,
+	}, {
+		.key	= { 0xef, 0x01, 0x23, 0x45 },
+		.klen	= 4,
+		.input	= { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			    0x00, 0x00 },
+		.ilen	= 10,
+		.result	= { 0xd6, 0xa1, 0x41, 0xa7, 0xec, 0x3c, 0x38, 0xdf,
+			    0xbd, 0x61 },
+		.rlen	= 10,
+	}, {
+		.key	= { 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF,
+		            0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
+		.klen	= 16,
+		.input	= { 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF },
+		.ilen	= 8,
+		.result	= { 0x69, 0x72, 0x36, 0x59, 0x1B, 0x52, 0x42, 0xB1 },
+		.rlen	= 8,
+	},
+};
+
+struct cipher_testvec arc4_dec_tv_template[] =
+{
+	{
+		.key	= { 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef },
+		.klen	= 8,
+		.input	= { 0x75, 0xb7, 0x87, 0x80, 0x99, 0xe0, 0xc5, 0x96 },
+		.ilen	= 8,
+		.result	= { 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef },
+		.rlen	= 8,
+	}, {
+		.key	= { 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef },
+		.klen	= 8,
+		.input	= { 0x74, 0x94, 0xc2, 0xe7, 0x10, 0x4b, 0x08, 0x79 },
+		.ilen	= 8,
+		.result	= { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
+		.rlen	= 8,
+	}, {
+		.key	= { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
+		.klen	= 8,
+		.input	= { 0xde, 0x18, 0x89, 0x41, 0xa3, 0x37, 0x5d, 0x3a },
+		.ilen	= 8,
+		.result	= { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
+		.rlen	= 8,
+	}, {
+		.key	= { 0xef, 0x01, 0x23, 0x45},
+		.klen	= 4,
+		.input	= { 0xd6, 0xa1, 0x41, 0xa7, 0xec, 0x3c, 0x38, 0xdf,
+			    0xbd, 0x61, 0x5a, 0x11, 0x62, 0xe1, 0xc7, 0xba,
+			    0x36, 0xb6, 0x78, 0x58 },
+		.ilen	= 20,
+		.result	= { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			    0x00, 0x00, 0x00, 0x00 },
+		.rlen	= 20,
+	}, {
+		.key	= { 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef },
+		.klen	= 8,
+		.input	= { 0x66, 0xa0, 0x94, 0x9f, 0x8a, 0xf7, 0xd6, 0x89,
+			    0x1f, 0x7f, 0x83, 0x2b, 0xa8, 0x33, 0xc0, 0x0c,
+			    0x89, 0x2e, 0xbe, 0x30, 0x14, 0x3c, 0xe2, 0x87,
+			    0x40, 0x01, 0x1e, 0xcf },
+		.ilen	= 28,
+		.result	= { 0x12, 0x34, 0x56, 0x78, 0x9A, 0xBC, 0xDE, 0xF0,
+			    0x12, 0x34, 0x56, 0x78, 0x9A, 0xBC, 0xDE, 0xF0,
+			    0x12, 0x34, 0x56, 0x78, 0x9A, 0xBC, 0xDE, 0xF0,
+			    0x12, 0x34, 0x56, 0x78 },
+		.rlen	= 28,
+	}, {
+		.key	= { 0xef, 0x01, 0x23, 0x45 },
+		.klen	= 4,
+		.input	= { 0xd6, 0xa1, 0x41, 0xa7, 0xec, 0x3c, 0x38, 0xdf,
+			    0xbd, 0x61 },
+		.ilen	= 10,
+		.result	= { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			    0x00, 0x00 },
+		.rlen	= 10,
+	}, {
+		.key	= { 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF,
+		            0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
+		.klen	= 16,
+		.input	= { 0x69, 0x72, 0x36, 0x59, 0x1B, 0x52, 0x42, 0xB1 },
+		.ilen	= 8,
+		.result	= { 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF },
+		.rlen	= 8,
+	},
+};
+
+
 /*
  * Compression stuff.
  */