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