Commit 3936f02b authored by David Howells's avatar David Howells
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crypto/krb5: Implement Kerberos crypto core 



Provide core structures, an encoding-type registry and basic module and
config bits for a generic Kerberos crypto library.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
cc: Herbert Xu <herbert@gondor.apana.org.au>
cc: "David S. Miller" <davem@davemloft.net>
cc: Chuck Lever <chuck.lever@oracle.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: Simon Horman <horms@kernel.org>
cc: linux-afs@lists.infradead.org
cc: linux-nfs@vger.kernel.org
cc: linux-crypto@vger.kernel.org
cc: netdev@vger.kernel.org
parent 1b80b6f4

crypto/Kconfig

+1 −0
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@@ -1472,5 +1472,6 @@ endif 
source "drivers/crypto/Kconfig"

source "crypto/asymmetric_keys/Kconfig"

source "certs/Kconfig"

source "crypto/krb5/Kconfig"



endif	# if CRYPTO

crypto/Makefile

+2 −0
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@@ -213,3 +213,5 @@ obj-$(CONFIG_CRYPTO_SIMD) += crypto_simd.o 
# Key derivation function

#

obj-$(CONFIG_CRYPTO_KDF800108_CTR) += kdf_sp800108.o



obj-$(CONFIG_CRYPTO_KRB5) += krb5/

crypto/krb5/Kconfig

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+14 −0
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config CRYPTO_KRB5

	tristate "Kerberos 5 crypto"

	select CRYPTO_MANAGER

	select CRYPTO_KRB5ENC

	select CRYPTO_AUTHENC

	select CRYPTO_SKCIPHER

	select CRYPTO_HASH_INFO

	select CRYPTO_SHA1

	select CRYPTO_CBC

	select CRYPTO_CTS

	select CRYPTO_AES

	help

	  Provide a library for provision of Kerberos-5-based crypto.  This is

	  intended for network filesystems to use.

crypto/krb5/Makefile

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# SPDX-License-Identifier: GPL-2.0

#

# Makefile for asymmetric cryptographic keys

#



krb5-y += \

	krb5_api.o



obj-$(CONFIG_CRYPTO_KRB5) += krb5.o

crypto/krb5/internal.h

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/* SPDX-License-Identifier: GPL-2.0-or-later */

/* Kerberos5 crypto internals

 *

 * Copyright (C) 2025 Red Hat, Inc. All Rights Reserved.

 * Written by David Howells (dhowells@redhat.com)

 */



#include <crypto/krb5.h>



/*

 * Profile used for key derivation and encryption.

 */

struct krb5_crypto_profile {

	 /* Pseudo-random function */

	int (*calc_PRF)(const struct krb5_enctype *krb5,

			const struct krb5_buffer *protocol_key,

			const struct krb5_buffer *octet_string,

			struct krb5_buffer *result,

			gfp_t gfp);



	/* Checksum key derivation */

	int (*calc_Kc)(const struct krb5_enctype *krb5,

		       const struct krb5_buffer *TK,

		       const struct krb5_buffer *usage_constant,

		       struct krb5_buffer *Kc,

		       gfp_t gfp);



	/* Encryption key derivation */

	int (*calc_Ke)(const struct krb5_enctype *krb5,

		       const struct krb5_buffer *TK,

		       const struct krb5_buffer *usage_constant,

		       struct krb5_buffer *Ke,

		       gfp_t gfp);



	 /* Integrity key derivation */

	int (*calc_Ki)(const struct krb5_enctype *krb5,

		       const struct krb5_buffer *TK,

		       const struct krb5_buffer *usage_constant,

		       struct krb5_buffer *Ki,

		       gfp_t gfp);



	/* Derive the keys needed for an encryption AEAD object. */

	int (*derive_encrypt_keys)(const struct krb5_enctype *krb5,

				   const struct krb5_buffer *TK,

				   unsigned int usage,

				   struct krb5_buffer *setkey,

				   gfp_t gfp);



	/* Directly load the keys needed for an encryption AEAD object. */

	int (*load_encrypt_keys)(const struct krb5_enctype *krb5,

				 const struct krb5_buffer *Ke,

				 const struct krb5_buffer *Ki,

				 struct krb5_buffer *setkey,

				 gfp_t gfp);



	/* Derive the key needed for a checksum hash object. */

	int (*derive_checksum_key)(const struct krb5_enctype *krb5,

				   const struct krb5_buffer *TK,

				   unsigned int usage,

				   struct krb5_buffer *setkey,

				   gfp_t gfp);



	/* Directly load the keys needed for a checksum hash object. */

	int (*load_checksum_key)(const struct krb5_enctype *krb5,

				 const struct krb5_buffer *Kc,

				 struct krb5_buffer *setkey,

				 gfp_t gfp);



	/* Encrypt data in-place, inserting confounder and checksum. */

	ssize_t (*encrypt)(const struct krb5_enctype *krb5,

			   struct crypto_aead *aead,

			   struct scatterlist *sg, unsigned int nr_sg,

			   size_t sg_len,

			   size_t data_offset, size_t data_len,

			   bool preconfounded);



	/* Decrypt data in-place, removing confounder and checksum */

	int (*decrypt)(const struct krb5_enctype *krb5,

		       struct crypto_aead *aead,

		       struct scatterlist *sg, unsigned int nr_sg,

		       size_t *_offset, size_t *_len);



	/* Generate a MIC on part of a packet, inserting the checksum */

	ssize_t (*get_mic)(const struct krb5_enctype *krb5,

			   struct crypto_shash *shash,

			   const struct krb5_buffer *metadata,

			   struct scatterlist *sg, unsigned int nr_sg,

			   size_t sg_len,

			   size_t data_offset, size_t data_len);



	/* Verify the MIC on a piece of data, removing the checksum */

	int (*verify_mic)(const struct krb5_enctype *krb5,

			  struct crypto_shash *shash,

			  const struct krb5_buffer *metadata,

			  struct scatterlist *sg, unsigned int nr_sg,

			  size_t *_offset, size_t *_len);

};



/*

 * Crypto size/alignment rounding convenience macros.

 */

#define crypto_roundup(X) ((unsigned int)round_up((X), CRYPTO_MINALIGN))



#define krb5_aead_size(TFM) \

	crypto_roundup(sizeof(struct aead_request) + crypto_aead_reqsize(TFM))

#define krb5_aead_ivsize(TFM) \

	crypto_roundup(crypto_aead_ivsize(TFM))

#define krb5_shash_size(TFM) \

	crypto_roundup(sizeof(struct shash_desc) + crypto_shash_descsize(TFM))

#define krb5_digest_size(TFM) \

	crypto_roundup(crypto_shash_digestsize(TFM))

#define round16(x) (((x) + 15) & ~15)