krb5.h

  1/* SPDX-License-Identifier: GPL-2.0-or-later */
  2/* Kerberos 5 crypto
  3 *
  4 * Copyright (C) 2025 Red Hat, Inc. All Rights Reserved.
  5 * Written by David Howells (dhowells@redhat.com)
  6 */
  7
  8#ifndef _CRYPTO_KRB5_H
  9#define _CRYPTO_KRB5_H
 10
 11#include <linux/crypto.h>
 12#include <crypto/aead.h>
 13#include <crypto/hash.h>
 14
 15struct crypto_shash;
 16struct scatterlist;
 17
 18/*
 19 * Per Kerberos v5 protocol spec crypto types from the wire.  These get mapped
 20 * to linux kernel crypto routines.
 21 */
 22#define KRB5_ENCTYPE_NULL			0x0000
 23#define KRB5_ENCTYPE_DES_CBC_CRC		0x0001	/* DES cbc mode with CRC-32 */
 24#define KRB5_ENCTYPE_DES_CBC_MD4		0x0002	/* DES cbc mode with RSA-MD4 */
 25#define KRB5_ENCTYPE_DES_CBC_MD5		0x0003	/* DES cbc mode with RSA-MD5 */
 26#define KRB5_ENCTYPE_DES_CBC_RAW		0x0004	/* DES cbc mode raw */
 27/* XXX deprecated? */
 28#define KRB5_ENCTYPE_DES3_CBC_SHA		0x0005	/* DES-3 cbc mode with NIST-SHA */
 29#define KRB5_ENCTYPE_DES3_CBC_RAW		0x0006	/* DES-3 cbc mode raw */
 30#define KRB5_ENCTYPE_DES_HMAC_SHA1		0x0008
 31#define KRB5_ENCTYPE_DES3_CBC_SHA1		0x0010
 32#define KRB5_ENCTYPE_AES128_CTS_HMAC_SHA1_96	0x0011
 33#define KRB5_ENCTYPE_AES256_CTS_HMAC_SHA1_96	0x0012
 34#define KRB5_ENCTYPE_AES128_CTS_HMAC_SHA256_128	0x0013
 35#define KRB5_ENCTYPE_AES256_CTS_HMAC_SHA384_192	0x0014
 36#define KRB5_ENCTYPE_ARCFOUR_HMAC		0x0017
 37#define KRB5_ENCTYPE_ARCFOUR_HMAC_EXP		0x0018
 38#define KRB5_ENCTYPE_CAMELLIA128_CTS_CMAC	0x0019
 39#define KRB5_ENCTYPE_CAMELLIA256_CTS_CMAC	0x001a
 40#define KRB5_ENCTYPE_UNKNOWN			0x01ff
 41
 42#define KRB5_CKSUMTYPE_CRC32			0x0001
 43#define KRB5_CKSUMTYPE_RSA_MD4			0x0002
 44#define KRB5_CKSUMTYPE_RSA_MD4_DES		0x0003
 45#define KRB5_CKSUMTYPE_DESCBC			0x0004
 46#define KRB5_CKSUMTYPE_RSA_MD5			0x0007
 47#define KRB5_CKSUMTYPE_RSA_MD5_DES		0x0008
 48#define KRB5_CKSUMTYPE_NIST_SHA			0x0009
 49#define KRB5_CKSUMTYPE_HMAC_SHA1_DES3		0x000c
 50#define KRB5_CKSUMTYPE_HMAC_SHA1_96_AES128	0x000f
 51#define KRB5_CKSUMTYPE_HMAC_SHA1_96_AES256	0x0010
 52#define KRB5_CKSUMTYPE_CMAC_CAMELLIA128		0x0011
 53#define KRB5_CKSUMTYPE_CMAC_CAMELLIA256		0x0012
 54#define KRB5_CKSUMTYPE_HMAC_SHA256_128_AES128	0x0013
 55#define KRB5_CKSUMTYPE_HMAC_SHA384_192_AES256	0x0014
 56#define KRB5_CKSUMTYPE_HMAC_MD5_ARCFOUR		-138 /* Microsoft md5 hmac cksumtype */
 57
 58/*
 59 * Constants used for key derivation
 60 */
 61/* from rfc3961 */
 62#define KEY_USAGE_SEED_CHECKSUM         (0x99)
 63#define KEY_USAGE_SEED_ENCRYPTION       (0xAA)
 64#define KEY_USAGE_SEED_INTEGRITY        (0x55)
 65
 66/*
 67 * Standard Kerberos error codes.
 68 */
 69#define KRB5_PROG_KEYTYPE_NOSUPP		-1765328233
 70
 71/*
 72 * Mode of operation.
 73 */
 74enum krb5_crypto_mode {
 75	KRB5_CHECKSUM_MODE,	/* Checksum only */
 76	KRB5_ENCRYPT_MODE,	/* Fully encrypted, possibly with integrity checksum */
 77};
 78
 79struct krb5_buffer {
 80	unsigned int	len;
 81	void		*data;
 82};
 83
 84/*
 85 * Kerberos encoding type definition.
 86 */
 87struct krb5_enctype {
 88	int		etype;		/* Encryption (key) type */
 89	int		ctype;		/* Checksum type */
 90	const char	*name;		/* "Friendly" name */
 91	const char	*encrypt_name;	/* Crypto encrypt+checksum name */
 92	const char	*cksum_name;	/* Crypto checksum name */
 93	const char	*hash_name;	/* Crypto hash name */
 94	const char	*derivation_enc; /* Cipher used in key derivation */
 95	u16		block_len;	/* Length of encryption block */
 96	u16		conf_len;	/* Length of confounder (normally == block_len) */
 97	u16		cksum_len;	/* Length of checksum */
 98	u16		key_bytes;	/* Length of raw key, in bytes */
 99	u16		key_len;	/* Length of final key, in bytes */
100	u16		hash_len;	/* Length of hash in bytes */
101	u16		prf_len;	/* Length of PRF() result in bytes */
102	u16		Kc_len;		/* Length of Kc in bytes */
103	u16		Ke_len;		/* Length of Ke in bytes */
104	u16		Ki_len;		/* Length of Ki in bytes */
105	bool		keyed_cksum;	/* T if a keyed cksum */
106
107	const struct krb5_crypto_profile *profile;
108
109	int (*random_to_key)(const struct krb5_enctype *krb5,
110			     const struct krb5_buffer *in,
111			     struct krb5_buffer *out);	/* complete key generation */
112};
113
114/*
115 * krb5_api.c
116 */
117const struct krb5_enctype *crypto_krb5_find_enctype(u32 enctype);
118size_t crypto_krb5_how_much_buffer(const struct krb5_enctype *krb5,
119				   enum krb5_crypto_mode mode,
120				   size_t data_size, size_t *_offset);
121size_t crypto_krb5_how_much_data(const struct krb5_enctype *krb5,
122				 enum krb5_crypto_mode mode,
123				 size_t *_buffer_size, size_t *_offset);
124void crypto_krb5_where_is_the_data(const struct krb5_enctype *krb5,
125				   enum krb5_crypto_mode mode,
126				   size_t *_offset, size_t *_len);
127struct crypto_aead *crypto_krb5_prepare_encryption(const struct krb5_enctype *krb5,
128						   const struct krb5_buffer *TK,
129						   u32 usage, gfp_t gfp);
130struct crypto_shash *crypto_krb5_prepare_checksum(const struct krb5_enctype *krb5,
131						  const struct krb5_buffer *TK,
132						  u32 usage, gfp_t gfp);
133ssize_t crypto_krb5_encrypt(const struct krb5_enctype *krb5,
134			    struct crypto_aead *aead,
135			    struct scatterlist *sg, unsigned int nr_sg,
136			    size_t sg_len,
137			    size_t data_offset, size_t data_len,
138			    bool preconfounded);
139int crypto_krb5_decrypt(const struct krb5_enctype *krb5,
140			struct crypto_aead *aead,
141			struct scatterlist *sg, unsigned int nr_sg,
142			size_t *_offset, size_t *_len);
143ssize_t crypto_krb5_get_mic(const struct krb5_enctype *krb5,
144			    struct crypto_shash *shash,
145			    const struct krb5_buffer *metadata,
146			    struct scatterlist *sg, unsigned int nr_sg,
147			    size_t sg_len,
148			    size_t data_offset, size_t data_len);
149int crypto_krb5_verify_mic(const struct krb5_enctype *krb5,
150			   struct crypto_shash *shash,
151			   const struct krb5_buffer *metadata,
152			   struct scatterlist *sg, unsigned int nr_sg,
153			   size_t *_offset, size_t *_len);
154
155/*
156 * krb5_kdf.c
157 */
158int crypto_krb5_calc_PRFplus(const struct krb5_enctype *krb5,
159			     const struct krb5_buffer *K,
160			     unsigned int L,
161			     const struct krb5_buffer *S,
162			     struct krb5_buffer *result,
163			     gfp_t gfp);
164
165#endif /* _CRYPTO_KRB5_H */