internal.h

  1/* SPDX-License-Identifier: GPL-2.0-or-later */
  2/* Kerberos5 crypto internals
  3 *
  4 * Copyright (C) 2025 Red Hat, Inc. All Rights Reserved.
  5 * Written by David Howells (dhowells@redhat.com)
  6 */
  7
  8#include <linux/scatterlist.h>
  9#include <crypto/krb5.h>
 10#include <crypto/hash.h>
 11#include <crypto/skcipher.h>
 12
 13/*
 14 * Profile used for key derivation and encryption.
 15 */
 16struct krb5_crypto_profile {
 17	 /* Pseudo-random function */
 18	int (*calc_PRF)(const struct krb5_enctype *krb5,
 19			const struct krb5_buffer *protocol_key,
 20			const struct krb5_buffer *octet_string,
 21			struct krb5_buffer *result,
 22			gfp_t gfp);
 23
 24	/* Checksum key derivation */
 25	int (*calc_Kc)(const struct krb5_enctype *krb5,
 26		       const struct krb5_buffer *TK,
 27		       const struct krb5_buffer *usage_constant,
 28		       struct krb5_buffer *Kc,
 29		       gfp_t gfp);
 30
 31	/* Encryption key derivation */
 32	int (*calc_Ke)(const struct krb5_enctype *krb5,
 33		       const struct krb5_buffer *TK,
 34		       const struct krb5_buffer *usage_constant,
 35		       struct krb5_buffer *Ke,
 36		       gfp_t gfp);
 37
 38	 /* Integrity key derivation */
 39	int (*calc_Ki)(const struct krb5_enctype *krb5,
 40		       const struct krb5_buffer *TK,
 41		       const struct krb5_buffer *usage_constant,
 42		       struct krb5_buffer *Ki,
 43		       gfp_t gfp);
 44
 45	/* Derive the keys needed for an encryption AEAD object. */
 46	int (*derive_encrypt_keys)(const struct krb5_enctype *krb5,
 47				   const struct krb5_buffer *TK,
 48				   unsigned int usage,
 49				   struct krb5_buffer *setkey,
 50				   gfp_t gfp);
 51
 52	/* Directly load the keys needed for an encryption AEAD object. */
 53	int (*load_encrypt_keys)(const struct krb5_enctype *krb5,
 54				 const struct krb5_buffer *Ke,
 55				 const struct krb5_buffer *Ki,
 56				 struct krb5_buffer *setkey,
 57				 gfp_t gfp);
 58
 59	/* Derive the key needed for a checksum hash object. */
 60	int (*derive_checksum_key)(const struct krb5_enctype *krb5,
 61				   const struct krb5_buffer *TK,
 62				   unsigned int usage,
 63				   struct krb5_buffer *setkey,
 64				   gfp_t gfp);
 65
 66	/* Directly load the keys needed for a checksum hash object. */
 67	int (*load_checksum_key)(const struct krb5_enctype *krb5,
 68				 const struct krb5_buffer *Kc,
 69				 struct krb5_buffer *setkey,
 70				 gfp_t gfp);
 71
 72	/* Encrypt data in-place, inserting confounder and checksum. */
 73	ssize_t (*encrypt)(const struct krb5_enctype *krb5,
 74			   struct crypto_aead *aead,
 75			   struct scatterlist *sg, unsigned int nr_sg,
 76			   size_t sg_len,
 77			   size_t data_offset, size_t data_len,
 78			   bool preconfounded);
 79
 80	/* Decrypt data in-place, removing confounder and checksum */
 81	int (*decrypt)(const struct krb5_enctype *krb5,
 82		       struct crypto_aead *aead,
 83		       struct scatterlist *sg, unsigned int nr_sg,
 84		       size_t *_offset, size_t *_len);
 85
 86	/* Generate a MIC on part of a packet, inserting the checksum */
 87	ssize_t (*get_mic)(const struct krb5_enctype *krb5,
 88			   struct crypto_shash *shash,
 89			   const struct krb5_buffer *metadata,
 90			   struct scatterlist *sg, unsigned int nr_sg,
 91			   size_t sg_len,
 92			   size_t data_offset, size_t data_len);
 93
 94	/* Verify the MIC on a piece of data, removing the checksum */
 95	int (*verify_mic)(const struct krb5_enctype *krb5,
 96			  struct crypto_shash *shash,
 97			  const struct krb5_buffer *metadata,
 98			  struct scatterlist *sg, unsigned int nr_sg,
 99			  size_t *_offset, size_t *_len);
100};
101
102/*
103 * Crypto size/alignment rounding convenience macros.
104 */
105#define crypto_roundup(X) ((unsigned int)round_up((X), CRYPTO_MINALIGN))
106
107#define krb5_aead_size(TFM) \
108	crypto_roundup(sizeof(struct aead_request) + crypto_aead_reqsize(TFM))
109#define krb5_aead_ivsize(TFM) \
110	crypto_roundup(crypto_aead_ivsize(TFM))
111#define krb5_shash_size(TFM) \
112	crypto_roundup(sizeof(struct shash_desc) + crypto_shash_descsize(TFM))
113#define krb5_digest_size(TFM) \
114	crypto_roundup(crypto_shash_digestsize(TFM))
115#define round16(x) (((x) + 15) & ~15)
116
117/*
118 * Self-testing data.
119 */
120struct krb5_prf_test {
121	u32 etype;
122	const char *name, *key, *octet, *prf;
123};
124
125struct krb5_key_test_one {
126	u32 use;
127	const char *key;
128};
129
130struct krb5_key_test {
131	u32 etype;
132	const char *name, *key;
133	struct krb5_key_test_one Kc, Ke, Ki;
134};
135
136struct krb5_enc_test {
137	u32 etype;
138	u32 usage;
139	const char *name, *plain, *conf, *K0, *Ke, *Ki, *ct;
140};
141
142struct krb5_mic_test {
143	u32 etype;
144	u32 usage;
145	const char *name, *plain, *K0, *Kc, *mic;
146};
147
148/*
149 * krb5_api.c
150 */
151struct crypto_aead *krb5_prepare_encryption(const struct krb5_enctype *krb5,
152					    const struct krb5_buffer *keys,
153					    gfp_t gfp);
154struct crypto_shash *krb5_prepare_checksum(const struct krb5_enctype *krb5,
155					   const struct krb5_buffer *Kc,
156					   gfp_t gfp);
157
158/*
159 * krb5_kdf.c
160 */
161int krb5_derive_Kc(const struct krb5_enctype *krb5, const struct krb5_buffer *TK,
162		   u32 usage, struct krb5_buffer *key, gfp_t gfp);
163int krb5_derive_Ke(const struct krb5_enctype *krb5, const struct krb5_buffer *TK,
164		   u32 usage, struct krb5_buffer *key, gfp_t gfp);
165int krb5_derive_Ki(const struct krb5_enctype *krb5, const struct krb5_buffer *TK,
166		   u32 usage, struct krb5_buffer *key, gfp_t gfp);
167
168/*
169 * rfc3961_simplified.c
170 */
171extern const struct krb5_crypto_profile rfc3961_simplified_profile;
172
173int crypto_shash_update_sg(struct shash_desc *desc, struct scatterlist *sg,
174			   size_t offset, size_t len);
175int authenc_derive_encrypt_keys(const struct krb5_enctype *krb5,
176				const struct krb5_buffer *TK,
177				unsigned int usage,
178				struct krb5_buffer *setkey,
179				gfp_t gfp);
180int authenc_load_encrypt_keys(const struct krb5_enctype *krb5,
181			      const struct krb5_buffer *Ke,
182			      const struct krb5_buffer *Ki,
183			      struct krb5_buffer *setkey,
184			      gfp_t gfp);
185int rfc3961_derive_checksum_key(const struct krb5_enctype *krb5,
186				const struct krb5_buffer *TK,
187				unsigned int usage,
188				struct krb5_buffer *setkey,
189				gfp_t gfp);
190int rfc3961_load_checksum_key(const struct krb5_enctype *krb5,
191			      const struct krb5_buffer *Kc,
192			      struct krb5_buffer *setkey,
193			      gfp_t gfp);
194ssize_t krb5_aead_encrypt(const struct krb5_enctype *krb5,
195			  struct crypto_aead *aead,
196			  struct scatterlist *sg, unsigned int nr_sg, size_t sg_len,
197			  size_t data_offset, size_t data_len,
198			  bool preconfounded);
199int krb5_aead_decrypt(const struct krb5_enctype *krb5,
200		      struct crypto_aead *aead,
201		      struct scatterlist *sg, unsigned int nr_sg,
202		      size_t *_offset, size_t *_len);
203ssize_t rfc3961_get_mic(const struct krb5_enctype *krb5,
204			struct crypto_shash *shash,
205			const struct krb5_buffer *metadata,
206			struct scatterlist *sg, unsigned int nr_sg, size_t sg_len,
207			size_t data_offset, size_t data_len);
208int rfc3961_verify_mic(const struct krb5_enctype *krb5,
209		       struct crypto_shash *shash,
210		       const struct krb5_buffer *metadata,
211		       struct scatterlist *sg, unsigned int nr_sg,
212		       size_t *_offset, size_t *_len);
213
214/*
215 * rfc3962_aes.c
216 */
217extern const struct krb5_enctype krb5_aes128_cts_hmac_sha1_96;
218extern const struct krb5_enctype krb5_aes256_cts_hmac_sha1_96;
219
220/*
221 * rfc6803_camellia.c
222 */
223extern const struct krb5_enctype krb5_camellia128_cts_cmac;
224extern const struct krb5_enctype krb5_camellia256_cts_cmac;
225
226/*
227 * rfc8009_aes2.c
228 */
229extern const struct krb5_enctype krb5_aes128_cts_hmac_sha256_128;
230extern const struct krb5_enctype krb5_aes256_cts_hmac_sha384_192;
231
232/*
233 * selftest.c
234 */
235#ifdef CONFIG_CRYPTO_KRB5_SELFTESTS
236int krb5_selftest(void);
237#else
238static inline int krb5_selftest(void) { return 0; }
239#endif
240
241/*
242 * selftest_data.c
243 */
244extern const struct krb5_prf_test krb5_prf_tests[];
245extern const struct krb5_key_test krb5_key_tests[];
246extern const struct krb5_enc_test krb5_enc_tests[];
247extern const struct krb5_mic_test krb5_mic_tests[];