lib/crypto/aescfb.c - linux/kernel/git/zohar/linux-integrity - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Minimal library implementation of AES in CFB mode
  *
  * Copyright 2023 Google LLC
  */

 #include <linux/module.h>

 #include <crypto/algapi.h>
 #include <crypto/aes.h>

 #include <asm/irqflags.h>

 static void aescfb_encrypt_block(const struct crypto_aes_ctx *ctx, void *dst,
 				 const void *src)
 {
 	unsigned long flags;

 	/*
 	 * In AES-CFB, the AES encryption operates on known 'plaintext' (the IV
 	 * and ciphertext), making it susceptible to timing attacks on the
 	 * encryption key. The AES library already mitigates this risk to some
 	 * extent by pulling the entire S-box into the caches before doing any
 	 * substitutions, but this strategy is more effective when running with
 	 * interrupts disabled.
 	 */
 	local_irq_save(flags);
 	aes_encrypt(ctx, dst, src);
 	local_irq_restore(flags);
 }

 /**
  * aescfb_encrypt - Perform AES-CFB encryption on a block of data
  *
  * @ctx:	The AES-CFB key schedule
  * @dst:	Pointer to the ciphertext output buffer
  * @src:	Pointer the plaintext (may equal @dst for encryption in place)
  * @len:	The size in bytes of the plaintext and ciphertext.
  * @iv:		The initialization vector (IV) to use for this block of data
  */
 void aescfb_encrypt(const struct crypto_aes_ctx *ctx, u8 *dst, const u8 *src,
 		    int len, const u8 iv[AES_BLOCK_SIZE])
 {
 	u8 ks[AES_BLOCK_SIZE];
 	const u8 *v = iv;

 	while (len > 0) {
 		aescfb_encrypt_block(ctx, ks, v);
 		crypto_xor_cpy(dst, src, ks, min(len, AES_BLOCK_SIZE));
 		v = dst;

 		dst += AES_BLOCK_SIZE;
 		src += AES_BLOCK_SIZE;
 		len -= AES_BLOCK_SIZE;
 	}

 	memzero_explicit(ks, sizeof(ks));
 }
 EXPORT_SYMBOL(aescfb_encrypt);

 /**
  * aescfb_decrypt - Perform AES-CFB decryption on a block of data
  *
  * @ctx:	The AES-CFB key schedule
  * @dst:	Pointer to the plaintext output buffer
  * @src:	Pointer the ciphertext (may equal @dst for decryption in place)
  * @len:	The size in bytes of the plaintext and ciphertext.
  * @iv:		The initialization vector (IV) to use for this block of data
  */
 void aescfb_decrypt(const struct crypto_aes_ctx *ctx, u8 *dst, const u8 *src,
 		    int len, const u8 iv[AES_BLOCK_SIZE])
 {
 	u8 ks[2][AES_BLOCK_SIZE];

 	aescfb_encrypt_block(ctx, ks[0], iv);

 	for (int i = 0; len > 0; i ^= 1) {
 		if (len > AES_BLOCK_SIZE)
 			/*
 			 * Generate the keystream for the next block before
 			 * performing the XOR, as that may update in place and
 			 * overwrite the ciphertext.
 			 */
 			aescfb_encrypt_block(ctx, ks[!i], src);

 		crypto_xor_cpy(dst, src, ks[i], min(len, AES_BLOCK_SIZE));

 		dst += AES_BLOCK_SIZE;
 		src += AES_BLOCK_SIZE;
 		len -= AES_BLOCK_SIZE;
 	}

 	memzero_explicit(ks, sizeof(ks));
 }
 EXPORT_SYMBOL(aescfb_decrypt);

 MODULE_DESCRIPTION("Generic AES-CFB library");
 MODULE_AUTHOR("Ard Biesheuvel <ardb@kernel.org>");
 MODULE_LICENSE("GPL");

 #ifndef CONFIG_CRYPTO_MANAGER_DISABLE_TESTS

 /*
  * Test code below. Vectors taken from crypto/testmgr.h
  */

 static struct {
 	u8	ptext[64];
 	u8	ctext[64];

 	u8	key[AES_MAX_KEY_SIZE];
 	u8	iv[AES_BLOCK_SIZE];

 	int	klen;
 	int	len;
 } const aescfb_tv[] __initconst = {
 	{ /* From NIST SP800-38A */
 		.key    = "\x2b\x7e\x15\x16\x28\xae\xd2\xa6"
 			  "\xab\xf7\x15\x88\x09\xcf\x4f\x3c",
 		.klen	= 16,
 		.iv	= "\x00\x01\x02\x03\x04\x05\x06\x07"
 			  "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
 		.ptext	= "\x6b\xc1\xbe\xe2\x2e\x40\x9f\x96"
 			  "\xe9\x3d\x7e\x11\x73\x93\x17\x2a"
 			  "\xae\x2d\x8a\x57\x1e\x03\xac\x9c"
 			  "\x9e\xb7\x6f\xac\x45\xaf\x8e\x51"
 			  "\x30\xc8\x1c\x46\xa3\x5c\xe4\x11"
 			  "\xe5\xfb\xc1\x19\x1a\x0a\x52\xef"
 			  "\xf6\x9f\x24\x45\xdf\x4f\x9b\x17"
 			  "\xad\x2b\x41\x7b\xe6\x6c\x37\x10",
 		.ctext	= "\x3b\x3f\xd9\x2e\xb7\x2d\xad\x20"
 			  "\x33\x34\x49\xf8\xe8\x3c\xfb\x4a"
 			  "\xc8\xa6\x45\x37\xa0\xb3\xa9\x3f"
 			  "\xcd\xe3\xcd\xad\x9f\x1c\xe5\x8b"
 			  "\x26\x75\x1f\x67\xa3\xcb\xb1\x40"
 			  "\xb1\x80\x8c\xf1\x87\xa4\xf4\xdf"
 			  "\xc0\x4b\x05\x35\x7c\x5d\x1c\x0e"
 			  "\xea\xc4\xc6\x6f\x9f\xf7\xf2\xe6",
 		.len	= 64,
 	}, {
 		.key	= "\x8e\x73\xb0\xf7\xda\x0e\x64\x52"
 			  "\xc8\x10\xf3\x2b\x80\x90\x79\xe5"
 			  "\x62\xf8\xea\xd2\x52\x2c\x6b\x7b",
 		.klen	= 24,
 		.iv	= "\x00\x01\x02\x03\x04\x05\x06\x07"
 			  "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
 		.ptext	= "\x6b\xc1\xbe\xe2\x2e\x40\x9f\x96"
 			  "\xe9\x3d\x7e\x11\x73\x93\x17\x2a"
 			  "\xae\x2d\x8a\x57\x1e\x03\xac\x9c"
 			  "\x9e\xb7\x6f\xac\x45\xaf\x8e\x51"
 			  "\x30\xc8\x1c\x46\xa3\x5c\xe4\x11"
 			  "\xe5\xfb\xc1\x19\x1a\x0a\x52\xef"
 			  "\xf6\x9f\x24\x45\xdf\x4f\x9b\x17"
 			  "\xad\x2b\x41\x7b\xe6\x6c\x37\x10",
 		.ctext	= "\xcd\xc8\x0d\x6f\xdd\xf1\x8c\xab"
 			  "\x34\xc2\x59\x09\xc9\x9a\x41\x74"
 			  "\x67\xce\x7f\x7f\x81\x17\x36\x21"
 			  "\x96\x1a\x2b\x70\x17\x1d\x3d\x7a"
 			  "\x2e\x1e\x8a\x1d\xd5\x9b\x88\xb1"
 			  "\xc8\xe6\x0f\xed\x1e\xfa\xc4\xc9"
 			  "\xc0\x5f\x9f\x9c\xa9\x83\x4f\xa0"
 			  "\x42\xae\x8f\xba\x58\x4b\x09\xff",
 		.len	= 64,
 	}, {
 		.key	= "\x60\x3d\xeb\x10\x15\xca\x71\xbe"
 			  "\x2b\x73\xae\xf0\x85\x7d\x77\x81"
 			  "\x1f\x35\x2c\x07\x3b\x61\x08\xd7"
 			  "\x2d\x98\x10\xa3\x09\x14\xdf\xf4",
 		.klen	= 32,
 		.iv	= "\x00\x01\x02\x03\x04\x05\x06\x07"
 			  "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
 		.ptext	= "\x6b\xc1\xbe\xe2\x2e\x40\x9f\x96"
 			  "\xe9\x3d\x7e\x11\x73\x93\x17\x2a"
 			  "\xae\x2d\x8a\x57\x1e\x03\xac\x9c"
 			  "\x9e\xb7\x6f\xac\x45\xaf\x8e\x51"
 			  "\x30\xc8\x1c\x46\xa3\x5c\xe4\x11"
 			  "\xe5\xfb\xc1\x19\x1a\x0a\x52\xef"
 			  "\xf6\x9f\x24\x45\xdf\x4f\x9b\x17"
 			  "\xad\x2b\x41\x7b\xe6\x6c\x37\x10",
 		.ctext	= "\xdc\x7e\x84\xbf\xda\x79\x16\x4b"
 			  "\x7e\xcd\x84\x86\x98\x5d\x38\x60"
 			  "\x39\xff\xed\x14\x3b\x28\xb1\xc8"
 			  "\x32\x11\x3c\x63\x31\xe5\x40\x7b"
 			  "\xdf\x10\x13\x24\x15\xe5\x4b\x92"
 			  "\xa1\x3e\xd0\xa8\x26\x7a\xe2\xf9"
 			  "\x75\xa3\x85\x74\x1a\xb9\xce\xf8"
 			  "\x20\x31\x62\x3d\x55\xb1\xe4\x71",
 		.len	= 64,
 	}, { /* > 16 bytes, not a multiple of 16 bytes */
 		.key	= "\x2b\x7e\x15\x16\x28\xae\xd2\xa6"
 			  "\xab\xf7\x15\x88\x09\xcf\x4f\x3c",
 		.klen	= 16,
 		.iv	= "\x00\x01\x02\x03\x04\x05\x06\x07"
 			  "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
 		.ptext	= "\x6b\xc1\xbe\xe2\x2e\x40\x9f\x96"
 			  "\xe9\x3d\x7e\x11\x73\x93\x17\x2a"
 			  "\xae",
 		.ctext	= "\x3b\x3f\xd9\x2e\xb7\x2d\xad\x20"
 			  "\x33\x34\x49\xf8\xe8\x3c\xfb\x4a"
 			  "\xc8",
 		.len	= 17,
 	}, { /* < 16 bytes */
 		.key	= "\x2b\x7e\x15\x16\x28\xae\xd2\xa6"
 			  "\xab\xf7\x15\x88\x09\xcf\x4f\x3c",
 		.klen	= 16,
 		.iv	= "\x00\x01\x02\x03\x04\x05\x06\x07"
 			  "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
 		.ptext	= "\x6b\xc1\xbe\xe2\x2e\x40\x9f",
 		.ctext	= "\x3b\x3f\xd9\x2e\xb7\x2d\xad",
 		.len	= 7,
 	},
 };

 static int __init libaescfb_init(void)
 {
 	for (int i = 0; i < ARRAY_SIZE(aescfb_tv); i++) {
 		struct crypto_aes_ctx ctx;
 		u8 buf[64];

 		if (aes_expandkey(&ctx, aescfb_tv[i].key, aescfb_tv[i].klen)) {
 			pr_err("aes_expandkey() failed on vector %d\n", i);
 			return -ENODEV;
 		}

 		aescfb_encrypt(&ctx, buf, aescfb_tv[i].ptext, aescfb_tv[i].len,
 			       aescfb_tv[i].iv);
 		if (memcmp(buf, aescfb_tv[i].ctext, aescfb_tv[i].len)) {
 			pr_err("aescfb_encrypt() #1 failed on vector %d\n", i);
 			return -ENODEV;
 		}

 		/* decrypt in place */
 		aescfb_decrypt(&ctx, buf, buf, aescfb_tv[i].len, aescfb_tv[i].iv);
 		if (memcmp(buf, aescfb_tv[i].ptext, aescfb_tv[i].len)) {
 			pr_err("aescfb_decrypt() failed on vector %d\n", i);
 			return -ENODEV;
 		}

 		/* encrypt in place */
 		aescfb_encrypt(&ctx, buf, buf, aescfb_tv[i].len, aescfb_tv[i].iv);
 		if (memcmp(buf, aescfb_tv[i].ctext, aescfb_tv[i].len)) {
 			pr_err("aescfb_encrypt() #2 failed on vector %d\n", i);

 			return -ENODEV;
 		}

 	}
 	return 0;
 }
 module_init(libaescfb_init);

 static void __exit libaescfb_exit(void)
 {
 }
 module_exit(libaescfb_exit);
 #endif
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Minimal library implementation of AES in CFB mode
	*
	* Copyright 2023 Google LLC
	*/

	#include <linux/module.h>

	#include <crypto/algapi.h>
	#include <crypto/aes.h>

	#include <asm/irqflags.h>

	static void aescfb_encrypt_block(const struct crypto_aes_ctx ctx, void dst,
	const void *src)
	{
	unsigned long flags;

	/*
	* In AES-CFB, the AES encryption operates on known 'plaintext' (the IV
	* and ciphertext), making it susceptible to timing attacks on the
	* encryption key. The AES library already mitigates this risk to some
	* extent by pulling the entire S-box into the caches before doing any
	* substitutions, but this strategy is more effective when running with
	* interrupts disabled.
	*/
	local_irq_save(flags);
	aes_encrypt(ctx, dst, src);
	local_irq_restore(flags);
	}

	/**
	* aescfb_encrypt - Perform AES-CFB encryption on a block of data
	*
	* @ctx: The AES-CFB key schedule
	* @dst: Pointer to the ciphertext output buffer
	* @src: Pointer the plaintext (may equal @dst for encryption in place)
	* @len: The size in bytes of the plaintext and ciphertext.
	* @iv: The initialization vector (IV) to use for this block of data
	*/
	void aescfb_encrypt(const struct crypto_aes_ctx ctx, u8 dst, const u8 *src,
	int len, const u8 iv[AES_BLOCK_SIZE])
	{
	u8 ks[AES_BLOCK_SIZE];
	const u8 *v = iv;

	while (len > 0) {
	aescfb_encrypt_block(ctx, ks, v);
	crypto_xor_cpy(dst, src, ks, min(len, AES_BLOCK_SIZE));
	v = dst;

	dst += AES_BLOCK_SIZE;
	src += AES_BLOCK_SIZE;
	len -= AES_BLOCK_SIZE;
	}

	memzero_explicit(ks, sizeof(ks));
	}
	EXPORT_SYMBOL(aescfb_encrypt);

	/**
	* aescfb_decrypt - Perform AES-CFB decryption on a block of data
	*
	* @ctx: The AES-CFB key schedule
	* @dst: Pointer to the plaintext output buffer
	* @src: Pointer the ciphertext (may equal @dst for decryption in place)
	* @len: The size in bytes of the plaintext and ciphertext.
	* @iv: The initialization vector (IV) to use for this block of data
	*/
	void aescfb_decrypt(const struct crypto_aes_ctx ctx, u8 dst, const u8 *src,
	int len, const u8 iv[AES_BLOCK_SIZE])
	{
	u8 ks[2][AES_BLOCK_SIZE];

	aescfb_encrypt_block(ctx, ks[0], iv);

	for (int i = 0; len > 0; i ^= 1) {
	if (len > AES_BLOCK_SIZE)
	/*
	* Generate the keystream for the next block before
	* performing the XOR, as that may update in place and
	* overwrite the ciphertext.
	*/
	aescfb_encrypt_block(ctx, ks[!i], src);

	crypto_xor_cpy(dst, src, ks[i], min(len, AES_BLOCK_SIZE));

	dst += AES_BLOCK_SIZE;
	src += AES_BLOCK_SIZE;
	len -= AES_BLOCK_SIZE;
	}

	memzero_explicit(ks, sizeof(ks));
	}
	EXPORT_SYMBOL(aescfb_decrypt);

	MODULE_DESCRIPTION("Generic AES-CFB library");
	MODULE_AUTHOR("Ard Biesheuvel <ardb@kernel.org>");
	MODULE_LICENSE("GPL");

	#ifndef CONFIG_CRYPTO_MANAGER_DISABLE_TESTS

	/*
	* Test code below. Vectors taken from crypto/testmgr.h
	*/

	static struct {
	u8 ptext[64];
	u8 ctext[64];

	u8 key[AES_MAX_KEY_SIZE];
	u8 iv[AES_BLOCK_SIZE];

	int klen;
	int len;
	} const aescfb_tv[] __initconst = {
	{ /* From NIST SP800-38A */
	.key = "\x2b\x7e\x15\x16\x28\xae\xd2\xa6"
	"\xab\xf7\x15\x88\x09\xcf\x4f\x3c",
	.klen = 16,
	.iv = "\x00\x01\x02\x03\x04\x05\x06\x07"
	"\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
	.ptext = "\x6b\xc1\xbe\xe2\x2e\x40\x9f\x96"
	"\xe9\x3d\x7e\x11\x73\x93\x17\x2a"
	"\xae\x2d\x8a\x57\x1e\x03\xac\x9c"
	"\x9e\xb7\x6f\xac\x45\xaf\x8e\x51"
	"\x30\xc8\x1c\x46\xa3\x5c\xe4\x11"
	"\xe5\xfb\xc1\x19\x1a\x0a\x52\xef"
	"\xf6\x9f\x24\x45\xdf\x4f\x9b\x17"
	"\xad\x2b\x41\x7b\xe6\x6c\x37\x10",
	.ctext = "\x3b\x3f\xd9\x2e\xb7\x2d\xad\x20"
	"\x33\x34\x49\xf8\xe8\x3c\xfb\x4a"
	"\xc8\xa6\x45\x37\xa0\xb3\xa9\x3f"
	"\xcd\xe3\xcd\xad\x9f\x1c\xe5\x8b"
	"\x26\x75\x1f\x67\xa3\xcb\xb1\x40"
	"\xb1\x80\x8c\xf1\x87\xa4\xf4\xdf"
	"\xc0\x4b\x05\x35\x7c\x5d\x1c\x0e"
	"\xea\xc4\xc6\x6f\x9f\xf7\xf2\xe6",
	.len = 64,
	}, {
	.key = "\x8e\x73\xb0\xf7\xda\x0e\x64\x52"
	"\xc8\x10\xf3\x2b\x80\x90\x79\xe5"
	"\x62\xf8\xea\xd2\x52\x2c\x6b\x7b",
	.klen = 24,
	.iv = "\x00\x01\x02\x03\x04\x05\x06\x07"
	"\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
	.ptext = "\x6b\xc1\xbe\xe2\x2e\x40\x9f\x96"
	"\xe9\x3d\x7e\x11\x73\x93\x17\x2a"
	"\xae\x2d\x8a\x57\x1e\x03\xac\x9c"
	"\x9e\xb7\x6f\xac\x45\xaf\x8e\x51"
	"\x30\xc8\x1c\x46\xa3\x5c\xe4\x11"
	"\xe5\xfb\xc1\x19\x1a\x0a\x52\xef"
	"\xf6\x9f\x24\x45\xdf\x4f\x9b\x17"
	"\xad\x2b\x41\x7b\xe6\x6c\x37\x10",
	.ctext = "\xcd\xc8\x0d\x6f\xdd\xf1\x8c\xab"
	"\x34\xc2\x59\x09\xc9\x9a\x41\x74"
	"\x67\xce\x7f\x7f\x81\x17\x36\x21"
	"\x96\x1a\x2b\x70\x17\x1d\x3d\x7a"
	"\x2e\x1e\x8a\x1d\xd5\x9b\x88\xb1"
	"\xc8\xe6\x0f\xed\x1e\xfa\xc4\xc9"
	"\xc0\x5f\x9f\x9c\xa9\x83\x4f\xa0"
	"\x42\xae\x8f\xba\x58\x4b\x09\xff",
	.len = 64,
	}, {
	.key = "\x60\x3d\xeb\x10\x15\xca\x71\xbe"
	"\x2b\x73\xae\xf0\x85\x7d\x77\x81"
	"\x1f\x35\x2c\x07\x3b\x61\x08\xd7"
	"\x2d\x98\x10\xa3\x09\x14\xdf\xf4",
	.klen = 32,
	.iv = "\x00\x01\x02\x03\x04\x05\x06\x07"
	"\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
	.ptext = "\x6b\xc1\xbe\xe2\x2e\x40\x9f\x96"
	"\xe9\x3d\x7e\x11\x73\x93\x17\x2a"
	"\xae\x2d\x8a\x57\x1e\x03\xac\x9c"
	"\x9e\xb7\x6f\xac\x45\xaf\x8e\x51"
	"\x30\xc8\x1c\x46\xa3\x5c\xe4\x11"
	"\xe5\xfb\xc1\x19\x1a\x0a\x52\xef"
	"\xf6\x9f\x24\x45\xdf\x4f\x9b\x17"
	"\xad\x2b\x41\x7b\xe6\x6c\x37\x10",
	.ctext = "\xdc\x7e\x84\xbf\xda\x79\x16\x4b"
	"\x7e\xcd\x84\x86\x98\x5d\x38\x60"
	"\x39\xff\xed\x14\x3b\x28\xb1\xc8"
	"\x32\x11\x3c\x63\x31\xe5\x40\x7b"
	"\xdf\x10\x13\x24\x15\xe5\x4b\x92"
	"\xa1\x3e\xd0\xa8\x26\x7a\xe2\xf9"
	"\x75\xa3\x85\x74\x1a\xb9\xce\xf8"
	"\x20\x31\x62\x3d\x55\xb1\xe4\x71",
	.len = 64,
	}, { /* > 16 bytes, not a multiple of 16 bytes */
	.key = "\x2b\x7e\x15\x16\x28\xae\xd2\xa6"
	"\xab\xf7\x15\x88\x09\xcf\x4f\x3c",
	.klen = 16,
	.iv = "\x00\x01\x02\x03\x04\x05\x06\x07"
	"\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
	.ptext = "\x6b\xc1\xbe\xe2\x2e\x40\x9f\x96"
	"\xe9\x3d\x7e\x11\x73\x93\x17\x2a"
	"\xae",
	.ctext = "\x3b\x3f\xd9\x2e\xb7\x2d\xad\x20"
	"\x33\x34\x49\xf8\xe8\x3c\xfb\x4a"
	"\xc8",
	.len = 17,
	}, { /* < 16 bytes */
	.key = "\x2b\x7e\x15\x16\x28\xae\xd2\xa6"
	"\xab\xf7\x15\x88\x09\xcf\x4f\x3c",
	.klen = 16,
	.iv = "\x00\x01\x02\x03\x04\x05\x06\x07"
	"\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
	.ptext = "\x6b\xc1\xbe\xe2\x2e\x40\x9f",
	.ctext = "\x3b\x3f\xd9\x2e\xb7\x2d\xad",
	.len = 7,
	},
	};

	static int __init libaescfb_init(void)
	{
	for (int i = 0; i < ARRAY_SIZE(aescfb_tv); i++) {
	struct crypto_aes_ctx ctx;
	u8 buf[64];

	if (aes_expandkey(&ctx, aescfb_tv[i].key, aescfb_tv[i].klen)) {
	pr_err("aes_expandkey() failed on vector %d\n", i);
	return -ENODEV;
	}

	aescfb_encrypt(&ctx, buf, aescfb_tv[i].ptext, aescfb_tv[i].len,
	aescfb_tv[i].iv);
	if (memcmp(buf, aescfb_tv[i].ctext, aescfb_tv[i].len)) {
	pr_err("aescfb_encrypt() #1 failed on vector %d\n", i);
	return -ENODEV;
	}

	/* decrypt in place */
	aescfb_decrypt(&ctx, buf, buf, aescfb_tv[i].len, aescfb_tv[i].iv);
	if (memcmp(buf, aescfb_tv[i].ptext, aescfb_tv[i].len)) {
	pr_err("aescfb_decrypt() failed on vector %d\n", i);
	return -ENODEV;
	}

	/* encrypt in place */
	aescfb_encrypt(&ctx, buf, buf, aescfb_tv[i].len, aescfb_tv[i].iv);
	if (memcmp(buf, aescfb_tv[i].ctext, aescfb_tv[i].len)) {
	pr_err("aescfb_encrypt() #2 failed on vector %d\n", i);

	return -ENODEV;
	}

	}
	return 0;
	}
	module_init(libaescfb_init);

	static void __exit libaescfb_exit(void)
	{
	}
	module_exit(libaescfb_exit);
	#endif