xref: /freebsd/sys/contrib/openzfs/include/sys/skein.h (revision 1f474190)
1 /*
2  * Interface declarations for Skein hashing.
3  * Source code author: Doug Whiting, 2008.
4  * This algorithm and source code is released to the public domain.
5  *
6  * The following compile-time switches may be defined to control some
7  * tradeoffs between speed, code size, error checking, and security.
8  *
9  * The "default" note explains what happens when the switch is not defined.
10  *
11  *  SKEIN_DEBUG            -- make callouts from inside Skein code
12  *                            to examine/display intermediate values.
13  *                            [default: no callouts (no overhead)]
14  *
15  *  SKEIN_ERR_CHECK        -- how error checking is handled inside Skein
16  *                            code. If not defined, most error checking
17  *                            is disabled (for performance). Otherwise,
18  *                            the switch value is interpreted as:
19  *                                0: use assert()      to flag errors
20  *                                1: return SKEIN_FAIL to flag errors
21  */
22 /* Copyright 2013 Doug Whiting. This code is released to the public domain. */
23 #ifndef	_SYS_SKEIN_H_
24 #define	_SYS_SKEIN_H_
25 
26 #ifdef  _KERNEL
27 #include <sys/types.h>		/* get size_t definition */
28 #else
29 #include <stdint.h>
30 #include <stdlib.h>
31 #endif
32 
33 #ifdef	__cplusplus
34 extern "C" {
35 #endif
36 
37 enum {
38 	SKEIN_SUCCESS = 0,	/* return codes from Skein calls */
39 	SKEIN_FAIL = 1,
40 	SKEIN_BAD_HASHLEN = 2
41 };
42 
43 #define	SKEIN_MODIFIER_WORDS	(2)	/* number of modifier (tweak) words */
44 
45 #define	SKEIN_256_STATE_WORDS	(4)
46 #define	SKEIN_512_STATE_WORDS	(8)
47 #define	SKEIN1024_STATE_WORDS	(16)
48 #define	SKEIN_MAX_STATE_WORDS	(16)
49 
50 #define	SKEIN_256_STATE_BYTES	(8 * SKEIN_256_STATE_WORDS)
51 #define	SKEIN_512_STATE_BYTES	(8 * SKEIN_512_STATE_WORDS)
52 #define	SKEIN1024_STATE_BYTES	(8 * SKEIN1024_STATE_WORDS)
53 
54 #define	SKEIN_256_STATE_BITS	(64 * SKEIN_256_STATE_WORDS)
55 #define	SKEIN_512_STATE_BITS	(64 * SKEIN_512_STATE_WORDS)
56 #define	SKEIN1024_STATE_BITS	(64 * SKEIN1024_STATE_WORDS)
57 
58 #define	SKEIN_256_BLOCK_BYTES	(8 * SKEIN_256_STATE_WORDS)
59 #define	SKEIN_512_BLOCK_BYTES	(8 * SKEIN_512_STATE_WORDS)
60 #define	SKEIN1024_BLOCK_BYTES	(8 * SKEIN1024_STATE_WORDS)
61 
62 typedef struct {
63 	size_t hashBitLen;	/* size of hash result, in bits */
64 	size_t bCnt;		/* current byte count in buffer b[] */
65 	/* tweak words: T[0]=byte cnt, T[1]=flags */
66 	uint64_t T[SKEIN_MODIFIER_WORDS];
67 } Skein_Ctxt_Hdr_t;
68 
69 typedef struct {		/*  256-bit Skein hash context structure */
70 	Skein_Ctxt_Hdr_t h;	/* common header context variables */
71 	uint64_t X[SKEIN_256_STATE_WORDS];	/* chaining variables */
72 	/* partial block buffer (8-byte aligned) */
73 	uint8_t b[SKEIN_256_BLOCK_BYTES];
74 } Skein_256_Ctxt_t;
75 
76 typedef struct {		/*  512-bit Skein hash context structure */
77 	Skein_Ctxt_Hdr_t h;	/* common header context variables */
78 	uint64_t X[SKEIN_512_STATE_WORDS];	/* chaining variables */
79 	/* partial block buffer (8-byte aligned) */
80 	uint8_t b[SKEIN_512_BLOCK_BYTES];
81 } Skein_512_Ctxt_t;
82 
83 typedef struct {		/* 1024-bit Skein hash context structure */
84 	Skein_Ctxt_Hdr_t h;	/* common header context variables */
85 	uint64_t X[SKEIN1024_STATE_WORDS];	/* chaining variables */
86 	/* partial block buffer (8-byte aligned) */
87 	uint8_t b[SKEIN1024_BLOCK_BYTES];
88 } Skein1024_Ctxt_t;
89 
90 /*   Skein APIs for (incremental) "straight hashing" */
91 int Skein_256_Init(Skein_256_Ctxt_t *ctx, size_t hashBitLen);
92 int Skein_512_Init(Skein_512_Ctxt_t *ctx, size_t hashBitLen);
93 int Skein1024_Init(Skein1024_Ctxt_t *ctx, size_t hashBitLen);
94 
95 int Skein_256_Update(Skein_256_Ctxt_t *ctx, const uint8_t *msg,
96     size_t msgByteCnt);
97 int Skein_512_Update(Skein_512_Ctxt_t *ctx, const uint8_t *msg,
98     size_t msgByteCnt);
99 int Skein1024_Update(Skein1024_Ctxt_t *ctx, const uint8_t *msg,
100     size_t msgByteCnt);
101 
102 int Skein_256_Final(Skein_256_Ctxt_t *ctx, uint8_t *hashVal);
103 int Skein_512_Final(Skein_512_Ctxt_t *ctx, uint8_t *hashVal);
104 int Skein1024_Final(Skein1024_Ctxt_t *ctx, uint8_t *hashVal);
105 
106 /*
107  * Skein APIs for "extended" initialization: MAC keys, tree hashing.
108  * After an InitExt() call, just use Update/Final calls as with Init().
109  *
110  * Notes: Same parameters as _Init() calls, plus treeInfo/key/keyBytes.
111  *          When keyBytes == 0 and treeInfo == SKEIN_SEQUENTIAL,
112  *              the results of InitExt() are identical to calling Init().
113  *          The function Init() may be called once to "precompute" the IV for
114  *              a given hashBitLen value, then by saving a copy of the context
115  *              the IV computation may be avoided in later calls.
116  *          Similarly, the function InitExt() may be called once per MAC key
117  *              to precompute the MAC IV, then a copy of the context saved and
118  *              reused for each new MAC computation.
119  */
120 int Skein_256_InitExt(Skein_256_Ctxt_t *ctx, size_t hashBitLen,
121     uint64_t treeInfo, const uint8_t *key, size_t keyBytes);
122 int Skein_512_InitExt(Skein_512_Ctxt_t *ctx, size_t hashBitLen,
123     uint64_t treeInfo, const uint8_t *key, size_t keyBytes);
124 int Skein1024_InitExt(Skein1024_Ctxt_t *ctx, size_t hashBitLen,
125     uint64_t treeInfo, const uint8_t *key, size_t keyBytes);
126 
127 /*
128  * Skein APIs for MAC and tree hash:
129  *	Final_Pad: pad, do final block, but no OUTPUT type
130  *	Output:    do just the output stage
131  */
132 int Skein_256_Final_Pad(Skein_256_Ctxt_t *ctx, uint8_t *hashVal);
133 int Skein_512_Final_Pad(Skein_512_Ctxt_t *ctx, uint8_t *hashVal);
134 int Skein1024_Final_Pad(Skein1024_Ctxt_t *ctx, uint8_t *hashVal);
135 
136 #ifndef	SKEIN_TREE_HASH
137 #define	SKEIN_TREE_HASH (1)
138 #endif
139 #if	SKEIN_TREE_HASH
140 int Skein_256_Output(Skein_256_Ctxt_t *ctx, uint8_t *hashVal);
141 int Skein_512_Output(Skein_512_Ctxt_t *ctx, uint8_t *hashVal);
142 int Skein1024_Output(Skein1024_Ctxt_t *ctx, uint8_t *hashVal);
143 #endif
144 
145 /*
146  * When you initialize a Skein KCF hashing method you can pass this param
147  * structure in cm_param to fine-tune the algorithm's defaults.
148  */
149 typedef struct skein_param {
150 	size_t	sp_digest_bitlen;		/* length of digest in bits */
151 } skein_param_t;
152 
153 /* Module definitions */
154 #ifdef	SKEIN_MODULE_IMPL
155 #define	CKM_SKEIN_256				"CKM_SKEIN_256"
156 #define	CKM_SKEIN_512				"CKM_SKEIN_512"
157 #define	CKM_SKEIN1024				"CKM_SKEIN1024"
158 #define	CKM_SKEIN_256_MAC			"CKM_SKEIN_256_MAC"
159 #define	CKM_SKEIN_512_MAC			"CKM_SKEIN_512_MAC"
160 #define	CKM_SKEIN1024_MAC			"CKM_SKEIN1024_MAC"
161 
162 typedef enum skein_mech_type {
163 	SKEIN_256_MECH_INFO_TYPE,
164 	SKEIN_512_MECH_INFO_TYPE,
165 	SKEIN1024_MECH_INFO_TYPE,
166 	SKEIN_256_MAC_MECH_INFO_TYPE,
167 	SKEIN_512_MAC_MECH_INFO_TYPE,
168 	SKEIN1024_MAC_MECH_INFO_TYPE
169 } skein_mech_type_t;
170 
171 #define	VALID_SKEIN_DIGEST_MECH(__mech)				\
172 	((int)(__mech) >= SKEIN_256_MECH_INFO_TYPE &&		\
173 	(__mech) <= SKEIN1024_MECH_INFO_TYPE)
174 #define	VALID_SKEIN_MAC_MECH(__mech)				\
175 	((int)(__mech) >= SKEIN_256_MAC_MECH_INFO_TYPE &&	\
176 	(__mech) <= SKEIN1024_MAC_MECH_INFO_TYPE)
177 #endif	/* SKEIN_MODULE_IMPL */
178 
179 #ifdef	__cplusplus
180 }
181 #endif
182 
183 #endif	/* _SYS_SKEIN_H_ */
184