gss_krb5_internal.h

  1/* SPDX-License-Identifier: GPL-2.0 or BSD-3-Clause */
  2/*
  3 * SunRPC GSS Kerberos 5 mechanism internal definitions
  4 *
  5 * Copyright (c) 2022 Oracle and/or its affiliates.
  6 */
  7
  8#ifndef _NET_SUNRPC_AUTH_GSS_KRB5_INTERNAL_H
  9#define _NET_SUNRPC_AUTH_GSS_KRB5_INTERNAL_H
 10
 11/*
 12 * The RFCs often specify payload lengths in bits. This helper
 13 * converts a specified bit-length to the number of octets/bytes.
 14 */
 15#define BITS2OCTETS(x)	((x) / 8)
 16
 17struct krb5_ctx;
 18
 19struct gss_krb5_enctype {
 20	const u32		etype;		/* encryption (key) type */
 21	const u32		ctype;		/* checksum type */
 22	const char		*name;		/* "friendly" name */
 23	const char		*encrypt_name;	/* crypto encrypt name */
 24	const char		*aux_cipher;	/* aux encrypt cipher name */
 25	const char		*cksum_name;	/* crypto checksum name */
 26	const u16		signalg;	/* signing algorithm */
 27	const u16		sealalg;	/* sealing algorithm */
 28	const u32		cksumlength;	/* checksum length */
 29	const u32		keyed_cksum;	/* is it a keyed cksum? */
 30	const u32		keybytes;	/* raw key len, in bytes */
 31	const u32		keylength;	/* protocol key length, in octets */
 32	const u32		Kc_length;	/* checksum subkey length, in octets */
 33	const u32		Ke_length;	/* encryption subkey length, in octets */
 34	const u32		Ki_length;	/* integrity subkey length, in octets */
 35
 36	int (*derive_key)(const struct gss_krb5_enctype *gk5e,
 37			  const struct xdr_netobj *in,
 38			  struct xdr_netobj *out,
 39			  const struct xdr_netobj *label,
 40			  gfp_t gfp_mask);
 41	u32 (*encrypt)(struct krb5_ctx *kctx, u32 offset,
 42		       struct xdr_buf *buf, struct page **pages);
 43	u32 (*decrypt)(struct krb5_ctx *kctx, u32 offset, u32 len,
 44		       struct xdr_buf *buf, u32 *headskip, u32 *tailskip);
 45	u32 (*get_mic)(struct krb5_ctx *kctx, struct xdr_buf *text,
 46		       struct xdr_netobj *token);
 47	u32 (*verify_mic)(struct krb5_ctx *kctx, struct xdr_buf *message_buffer,
 48			  struct xdr_netobj *read_token);
 49	u32 (*wrap)(struct krb5_ctx *kctx, int offset,
 50		    struct xdr_buf *buf, struct page **pages);
 51	u32 (*unwrap)(struct krb5_ctx *kctx, int offset, int len,
 52		      struct xdr_buf *buf, unsigned int *slack,
 53		      unsigned int *align);
 54};
 55
 56/* krb5_ctx flags definitions */
 57#define KRB5_CTX_FLAG_INITIATOR         0x00000001
 58#define KRB5_CTX_FLAG_ACCEPTOR_SUBKEY   0x00000004
 59
 60struct krb5_ctx {
 61	int			initiate; /* 1 = initiating, 0 = accepting */
 62	u32			enctype;
 63	u32			flags;
 64	const struct gss_krb5_enctype *gk5e; /* enctype-specific info */
 65	struct crypto_sync_skcipher *enc;
 66	struct crypto_sync_skcipher *seq;
 67	struct crypto_sync_skcipher *acceptor_enc;
 68	struct crypto_sync_skcipher *initiator_enc;
 69	struct crypto_sync_skcipher *acceptor_enc_aux;
 70	struct crypto_sync_skcipher *initiator_enc_aux;
 71	struct crypto_ahash	*acceptor_sign;
 72	struct crypto_ahash	*initiator_sign;
 73	struct crypto_ahash	*initiator_integ;
 74	struct crypto_ahash	*acceptor_integ;
 75	u8			Ksess[GSS_KRB5_MAX_KEYLEN]; /* session key */
 76	u8			cksum[GSS_KRB5_MAX_KEYLEN];
 77	atomic_t		seq_send;
 78	atomic64_t		seq_send64;
 79	time64_t		endtime;
 80	struct xdr_netobj	mech_used;
 81};
 82
 83/*
 84 * GSS Kerberos 5 mechanism Per-Message calls.
 85 */
 86
 87u32 gss_krb5_get_mic_v2(struct krb5_ctx *ctx, struct xdr_buf *text,
 88			struct xdr_netobj *token);
 89
 90u32 gss_krb5_verify_mic_v2(struct krb5_ctx *ctx, struct xdr_buf *message_buffer,
 91			   struct xdr_netobj *read_token);
 92
 93u32 gss_krb5_wrap_v2(struct krb5_ctx *kctx, int offset,
 94		     struct xdr_buf *buf, struct page **pages);
 95
 96u32 gss_krb5_unwrap_v2(struct krb5_ctx *kctx, int offset, int len,
 97		       struct xdr_buf *buf, unsigned int *slack,
 98		       unsigned int *align);
 99
100/*
101 * Implementation internal functions
102 */
103
104/* Key Derivation Functions */
105
106int krb5_derive_key_v2(const struct gss_krb5_enctype *gk5e,
107		       const struct xdr_netobj *inkey,
108		       struct xdr_netobj *outkey,
109		       const struct xdr_netobj *label,
110		       gfp_t gfp_mask);
111
112int krb5_kdf_hmac_sha2(const struct gss_krb5_enctype *gk5e,
113		       const struct xdr_netobj *inkey,
114		       struct xdr_netobj *outkey,
115		       const struct xdr_netobj *in_constant,
116		       gfp_t gfp_mask);
117
118int krb5_kdf_feedback_cmac(const struct gss_krb5_enctype *gk5e,
119			   const struct xdr_netobj *inkey,
120			   struct xdr_netobj *outkey,
121			   const struct xdr_netobj *in_constant,
122			   gfp_t gfp_mask);
123
124/**
125 * krb5_derive_key - Derive a subkey from a protocol key
126 * @kctx: Kerberos 5 context
127 * @inkey: base protocol key
128 * @outkey: OUT: derived key
129 * @usage: key usage value
130 * @seed: key usage seed (one octet)
131 * @gfp_mask: memory allocation control flags
132 *
133 * Caller sets @outkey->len to the desired length of the derived key.
134 *
135 * On success, returns 0 and fills in @outkey. A negative errno value
136 * is returned on failure.
137 */
138static inline int krb5_derive_key(struct krb5_ctx *kctx,
139				  const struct xdr_netobj *inkey,
140				  struct xdr_netobj *outkey,
141				  u32 usage, u8 seed, gfp_t gfp_mask)
142{
143	const struct gss_krb5_enctype *gk5e = kctx->gk5e;
144	u8 label_data[GSS_KRB5_K5CLENGTH];
145	struct xdr_netobj label = {
146		.len	= sizeof(label_data),
147		.data	= label_data,
148	};
149	__be32 *p = (__be32 *)label_data;
150
151	*p = cpu_to_be32(usage);
152	label_data[4] = seed;
153	return gk5e->derive_key(gk5e, inkey, outkey, &label, gfp_mask);
154}
155
156void krb5_make_confounder(u8 *p, int conflen);
157
158u32 gss_krb5_checksum(struct crypto_ahash *tfm, char *header, int hdrlen,
159		      const struct xdr_buf *body, int body_offset,
160		      struct xdr_netobj *cksumout);
161
162u32 krb5_encrypt(struct crypto_sync_skcipher *key, void *iv, void *in,
163		 void *out, int length);
164
165int xdr_extend_head(struct xdr_buf *buf, unsigned int base,
166		    unsigned int shiftlen);
167
168u32 gss_krb5_aes_encrypt(struct krb5_ctx *kctx, u32 offset,
169			 struct xdr_buf *buf, struct page **pages);
170
171u32 gss_krb5_aes_decrypt(struct krb5_ctx *kctx, u32 offset, u32 len,
172			 struct xdr_buf *buf, u32 *plainoffset, u32 *plainlen);
173
174u32 krb5_etm_encrypt(struct krb5_ctx *kctx, u32 offset, struct xdr_buf *buf,
175		     struct page **pages);
176
177u32 krb5_etm_decrypt(struct krb5_ctx *kctx, u32 offset, u32 len,
178		     struct xdr_buf *buf, u32 *headskip, u32 *tailskip);
179
180#if IS_ENABLED(CONFIG_KUNIT)
181void krb5_nfold(u32 inbits, const u8 *in, u32 outbits, u8 *out);
182const struct gss_krb5_enctype *gss_krb5_lookup_enctype(u32 etype);
183int krb5_cbc_cts_encrypt(struct crypto_sync_skcipher *cts_tfm,
184			 struct crypto_sync_skcipher *cbc_tfm, u32 offset,
185			 struct xdr_buf *buf, struct page **pages,
186			 u8 *iv, unsigned int ivsize);
187int krb5_cbc_cts_decrypt(struct crypto_sync_skcipher *cts_tfm,
188			 struct crypto_sync_skcipher *cbc_tfm,
189			 u32 offset, struct xdr_buf *buf);
190u32 krb5_etm_checksum(struct crypto_sync_skcipher *cipher,
191		      struct crypto_ahash *tfm, const struct xdr_buf *body,
192		      int body_offset, struct xdr_netobj *cksumout);
193#endif
194
195#endif /* _NET_SUNRPC_AUTH_GSS_KRB5_INTERNAL_H */