1#ifndef _SKEIN_H_
2#define _SKEIN_H_     1
3/**************************************************************************
4**
5** Interface declarations and internal definitions for Skein hashing.
6**
7** Source code author: Doug Whiting, 2008.
8**
9** This algorithm and source code is released to the public domain.
10**
11***************************************************************************
12**
13** The following compile-time switches may be defined to control some
14** tradeoffs between speed, code size, error checking, and security.
15**
16** The "default" note explains what happens when the switch is not defined.
17**
18**  SKEIN_ERR_CHECK        -- how error checking is handled inside Skein
19**                            code. If not defined, most error checking
20**                            is disabled (for performance). Otherwise,
21**                            the switch value is interpreted as:
22**                                0: use assert()      to flag errors
23**                                1: return SKEIN_FAIL to flag errors
24**
25***************************************************************************/
26
27/*Skein digest sizes for crypto api*/
28#define SKEIN256_DIGEST_BIT_SIZE 256
29#define SKEIN512_DIGEST_BIT_SIZE 512
30#define SKEIN1024_DIGEST_BIT_SIZE 1024
31
32/* below two prototype assume we are handed aligned data */
33#define skein_put64_lsb_first(dst08, src64, b_cnt) memcpy(dst08, src64, b_cnt)
34#define skein_get64_lsb_first(dst64, src08, w_cnt) \
35		memcpy(dst64, src08, 8*(w_cnt))
36#define skein_swap64(w64)  (w64)
37
38enum {
39	SKEIN_SUCCESS         =      0, /* return codes from Skein calls */
40	SKEIN_FAIL            =      1,
41	SKEIN_BAD_HASHLEN     =      2
42};
43
44#define  SKEIN_MODIFIER_WORDS   2 /* number of modifier (tweak) words */
45
46#define  SKEIN_256_STATE_WORDS  4
47#define  SKEIN_512_STATE_WORDS  8
48#define  SKEIN_1024_STATE_WORDS 16
49#define  SKEIN_MAX_STATE_WORDS	16
50
51#define  SKEIN_256_STATE_BYTES  (8*SKEIN_256_STATE_WORDS)
52#define  SKEIN_512_STATE_BYTES  (8*SKEIN_512_STATE_WORDS)
53#define  SKEIN_1024_STATE_BYTES  (8*SKEIN_1024_STATE_WORDS)
54
55#define  SKEIN_256_STATE_BITS  (64*SKEIN_256_STATE_WORDS)
56#define  SKEIN_512_STATE_BITS  (64*SKEIN_512_STATE_WORDS)
57#define  SKEIN_1024_STATE_BITS  (64*SKEIN_1024_STATE_WORDS)
58
59#define  SKEIN_256_BLOCK_BYTES  (8*SKEIN_256_STATE_WORDS)
60#define  SKEIN_512_BLOCK_BYTES  (8*SKEIN_512_STATE_WORDS)
61#define  SKEIN_1024_BLOCK_BYTES  (8*SKEIN_1024_STATE_WORDS)
62
63struct skein_ctx_hdr {
64	size_t hash_bit_len;		/* size of hash result, in bits */
65	size_t b_cnt;			/* current byte count in buffer b[] */
66	u64 tweak[SKEIN_MODIFIER_WORDS]; /* tweak[0]=byte cnt, tweak[1]=flags */
67};
68
69struct skein_256_ctx { /* 256-bit Skein hash context structure */
70	struct skein_ctx_hdr h;		/* common header context variables */
71	u64 x[SKEIN_256_STATE_WORDS];	/* chaining variables */
72	u8 b[SKEIN_256_BLOCK_BYTES];	/* partial block buf (8-byte aligned) */
73};
74
75struct skein_512_ctx { /* 512-bit Skein hash context structure */
76	struct skein_ctx_hdr h;		/* common header context variables */
77	u64 x[SKEIN_512_STATE_WORDS];	/* chaining variables */
78	u8 b[SKEIN_512_BLOCK_BYTES];	/* partial block buf (8-byte aligned) */
79};
80
81struct skein_1024_ctx { /* 1024-bit Skein hash context structure */
82	struct skein_ctx_hdr h;		/* common header context variables */
83	u64 x[SKEIN_1024_STATE_WORDS];	/* chaining variables */
84	u8 b[SKEIN_1024_BLOCK_BYTES];	/* partial block buf (8-byte aligned) */
85};
86
87static inline u64 rotl_64(u64 x, u8 N)
88{
89	return (x << N) | (x >> (64 - N));
90}
91
92/* Skein APIs for (incremental) "straight hashing" */
93int skein_256_init(struct skein_256_ctx *ctx, size_t hash_bit_len);
94int skein_512_init(struct skein_512_ctx *ctx, size_t hash_bit_len);
95int skein_1024_init(struct skein_1024_ctx *ctx, size_t hash_bit_len);
96
97int skein_256_update(struct skein_256_ctx *ctx, const u8 *msg,
98		     size_t msg_byte_cnt);
99int skein_512_update(struct skein_512_ctx *ctx, const u8 *msg,
100		     size_t msg_byte_cnt);
101int skein_1024_update(struct skein_1024_ctx *ctx, const u8 *msg,
102		      size_t msg_byte_cnt);
103
104int skein_256_final(struct skein_256_ctx *ctx, u8 *hash_val);
105int skein_512_final(struct skein_512_ctx *ctx, u8 *hash_val);
106int skein_1024_final(struct skein_1024_ctx *ctx, u8 *hash_val);
107
108/*
109**   Skein APIs for "extended" initialization: MAC keys, tree hashing.
110**   After an init_ext() call, just use update/final calls as with init().
111**
112**   Notes: Same parameters as _init() calls, plus tree_info/key/key_bytes.
113**          When key_bytes == 0 and tree_info == SKEIN_SEQUENTIAL,
114**              the results of init_ext() are identical to calling init().
115**          The function init() may be called once to "precompute" the IV for
116**              a given hash_bit_len value, then by saving a copy of the context
117**              the IV computation may be avoided in later calls.
118**          Similarly, the function init_ext() may be called once per MAC key
119**              to precompute the MAC IV, then a copy of the context saved and
120**              reused for each new MAC computation.
121**/
122int skein_256_init_ext(struct skein_256_ctx *ctx, size_t hash_bit_len,
123		       u64 tree_info, const u8 *key, size_t key_bytes);
124int skein_512_init_ext(struct skein_512_ctx *ctx, size_t hash_bit_len,
125		       u64 tree_info, const u8 *key, size_t key_bytes);
126int skein_1024_init_ext(struct skein_1024_ctx *ctx, size_t hash_bit_len,
127			u64 tree_info, const u8 *key, size_t key_bytes);
128
129/*
130**   Skein APIs for MAC and tree hash:
131**      final_pad:  pad, do final block, but no OUTPUT type
132**      output:     do just the output stage
133*/
134int skein_256_final_pad(struct skein_256_ctx *ctx, u8 *hash_val);
135int skein_512_final_pad(struct skein_512_ctx *ctx, u8 *hash_val);
136int skein_1024_final_pad(struct skein_1024_ctx *ctx, u8 *hash_val);
137
138#ifndef SKEIN_TREE_HASH
139#define SKEIN_TREE_HASH (1)
140#endif
141#if  SKEIN_TREE_HASH
142int skein_256_output(struct skein_256_ctx *ctx, u8 *hash_val);
143int skein_512_output(struct skein_512_ctx *ctx, u8 *hash_val);
144int skein_1024_output(struct skein_1024_ctx *ctx, u8 *hash_val);
145#endif
146
147/*****************************************************************
148** "Internal" Skein definitions
149**    -- not needed for sequential hashing API, but will be
150**           helpful for other uses of Skein (e.g., tree hash mode).
151**    -- included here so that they can be shared between
152**           reference and optimized code.
153******************************************************************/
154
155/* tweak word tweak[1]: bit field starting positions */
156#define SKEIN_T1_BIT(BIT)       ((BIT) - 64)      /* second word  */
157
158#define SKEIN_T1_POS_TREE_LVL   SKEIN_T1_BIT(112) /* 112..118 hash tree level */
159#define SKEIN_T1_POS_BIT_PAD    SKEIN_T1_BIT(119) /* 119 part. final in byte */
160#define SKEIN_T1_POS_BLK_TYPE   SKEIN_T1_BIT(120) /* 120..125 type field `*/
161#define SKEIN_T1_POS_FIRST      SKEIN_T1_BIT(126) /* 126      first blk flag */
162#define SKEIN_T1_POS_FINAL      SKEIN_T1_BIT(127) /* 127      final blk flag */
163
164/* tweak word tweak[1]: flag bit definition(s) */
165#define SKEIN_T1_FLAG_FIRST     (((u64)  1) << SKEIN_T1_POS_FIRST)
166#define SKEIN_T1_FLAG_FINAL     (((u64)  1) << SKEIN_T1_POS_FINAL)
167#define SKEIN_T1_FLAG_BIT_PAD   (((u64)  1) << SKEIN_T1_POS_BIT_PAD)
168
169/* tweak word tweak[1]: tree level bit field mask */
170#define SKEIN_T1_TREE_LVL_MASK  (((u64)0x7F) << SKEIN_T1_POS_TREE_LVL)
171#define SKEIN_T1_TREE_LEVEL(n)  (((u64) (n)) << SKEIN_T1_POS_TREE_LVL)
172
173/* tweak word tweak[1]: block type field */
174#define SKEIN_BLK_TYPE_KEY       (0) /* key, for MAC and KDF */
175#define SKEIN_BLK_TYPE_CFG       (4) /* configuration block */
176#define SKEIN_BLK_TYPE_PERS      (8) /* personalization string */
177#define SKEIN_BLK_TYPE_PK       (12) /* pubkey (for digital sigs) */
178#define SKEIN_BLK_TYPE_KDF      (16) /* key identifier for KDF */
179#define SKEIN_BLK_TYPE_NONCE    (20) /* nonce for PRNG */
180#define SKEIN_BLK_TYPE_MSG      (48) /* message processing */
181#define SKEIN_BLK_TYPE_OUT      (63) /* output stage */
182#define SKEIN_BLK_TYPE_MASK     (63) /* bit field mask */
183
184#define SKEIN_T1_BLK_TYPE(T)   (((u64) (SKEIN_BLK_TYPE_##T)) << \
185					SKEIN_T1_POS_BLK_TYPE)
186#define SKEIN_T1_BLK_TYPE_KEY   SKEIN_T1_BLK_TYPE(KEY)  /* for MAC and KDF */
187#define SKEIN_T1_BLK_TYPE_CFG   SKEIN_T1_BLK_TYPE(CFG)  /* config block */
188#define SKEIN_T1_BLK_TYPE_PERS  SKEIN_T1_BLK_TYPE(PERS) /* personalization */
189#define SKEIN_T1_BLK_TYPE_PK    SKEIN_T1_BLK_TYPE(PK)   /* pubkey (for sigs) */
190#define SKEIN_T1_BLK_TYPE_KDF   SKEIN_T1_BLK_TYPE(KDF)  /* key ident for KDF */
191#define SKEIN_T1_BLK_TYPE_NONCE SKEIN_T1_BLK_TYPE(NONCE)/* nonce for PRNG */
192#define SKEIN_T1_BLK_TYPE_MSG   SKEIN_T1_BLK_TYPE(MSG)  /* message processing */
193#define SKEIN_T1_BLK_TYPE_OUT   SKEIN_T1_BLK_TYPE(OUT)  /* output stage */
194#define SKEIN_T1_BLK_TYPE_MASK  SKEIN_T1_BLK_TYPE(MASK) /* field bit mask */
195
196#define SKEIN_T1_BLK_TYPE_CFG_FINAL    (SKEIN_T1_BLK_TYPE_CFG | \
197					SKEIN_T1_FLAG_FINAL)
198#define SKEIN_T1_BLK_TYPE_OUT_FINAL    (SKEIN_T1_BLK_TYPE_OUT | \
199					SKEIN_T1_FLAG_FINAL)
200
201#define SKEIN_VERSION           (1)
202
203#ifndef SKEIN_ID_STRING_LE      /* allow compile-time personalization */
204#define SKEIN_ID_STRING_LE      (0x33414853) /* "SHA3" (little-endian)*/
205#endif
206
207#define SKEIN_MK_64(hi32, lo32)  ((lo32) + (((u64) (hi32)) << 32))
208#define SKEIN_SCHEMA_VER        SKEIN_MK_64(SKEIN_VERSION, SKEIN_ID_STRING_LE)
209#define SKEIN_KS_PARITY         SKEIN_MK_64(0x1BD11BDA, 0xA9FC1A22)
210
211#define SKEIN_CFG_STR_LEN       (4*8)
212
213/* bit field definitions in config block tree_info word */
214#define SKEIN_CFG_TREE_LEAF_SIZE_POS  (0)
215#define SKEIN_CFG_TREE_NODE_SIZE_POS  (8)
216#define SKEIN_CFG_TREE_MAX_LEVEL_POS  (16)
217
218#define SKEIN_CFG_TREE_LEAF_SIZE_MSK (((u64)0xFF) << \
219					SKEIN_CFG_TREE_LEAF_SIZE_POS)
220#define SKEIN_CFG_TREE_NODE_SIZE_MSK (((u64)0xFF) << \
221					SKEIN_CFG_TREE_NODE_SIZE_POS)
222#define SKEIN_CFG_TREE_MAX_LEVEL_MSK (((u64)0xFF) << \
223					SKEIN_CFG_TREE_MAX_LEVEL_POS)
224
225#define SKEIN_CFG_TREE_INFO(leaf, node, max_lvl)                   \
226	((((u64)(leaf))   << SKEIN_CFG_TREE_LEAF_SIZE_POS) |    \
227	 (((u64)(node))   << SKEIN_CFG_TREE_NODE_SIZE_POS) |    \
228	 (((u64)(max_lvl)) << SKEIN_CFG_TREE_MAX_LEVEL_POS))
229
230/* use as tree_info in InitExt() call for sequential processing */
231#define SKEIN_CFG_TREE_INFO_SEQUENTIAL SKEIN_CFG_TREE_INFO(0, 0, 0)
232
233/*
234**   Skein macros for getting/setting tweak words, etc.
235**   These are useful for partial input bytes, hash tree init/update, etc.
236**/
237#define skein_get_tweak(ctx_ptr, TWK_NUM)          ((ctx_ptr)->h.tweak[TWK_NUM])
238#define skein_set_tweak(ctx_ptr, TWK_NUM, t_val) { \
239		(ctx_ptr)->h.tweak[TWK_NUM] = (t_val); \
240	}
241
242#define skein_get_T0(ctx_ptr)     skein_get_tweak(ctx_ptr, 0)
243#define skein_get_T1(ctx_ptr)     skein_get_tweak(ctx_ptr, 1)
244#define skein_set_T0(ctx_ptr, T0) skein_set_tweak(ctx_ptr, 0, T0)
245#define skein_set_T1(ctx_ptr, T1) skein_set_tweak(ctx_ptr, 1, T1)
246
247/* set both tweak words at once */
248#define skein_set_T0_T1(ctx_ptr, T0, T1)           \
249	{                                          \
250	skein_set_T0(ctx_ptr, (T0));               \
251	skein_set_T1(ctx_ptr, (T1));               \
252	}
253
254#define skein_set_type(ctx_ptr, BLK_TYPE)         \
255	skein_set_T1(ctx_ptr, SKEIN_T1_BLK_TYPE_##BLK_TYPE)
256
257/*
258 * setup for starting with a new type:
259 * h.tweak[0]=0; h.tweak[1] = NEW_TYPE; h.b_cnt=0;
260 */
261#define skein_start_new_type(ctx_ptr, BLK_TYPE) { \
262		skein_set_T0_T1(ctx_ptr, 0, SKEIN_T1_FLAG_FIRST | \
263				SKEIN_T1_BLK_TYPE_##BLK_TYPE); \
264		(ctx_ptr)->h.b_cnt = 0; \
265	}
266
267#define skein_clear_first_flag(hdr) { \
268		(hdr).tweak[1] &= ~SKEIN_T1_FLAG_FIRST; \
269	}
270#define skein_set_bit_pad_flag(hdr) { \
271		(hdr).tweak[1] |=  SKEIN_T1_FLAG_BIT_PAD; \
272	}
273
274#define skein_set_tree_level(hdr, height) { \
275		(hdr).tweak[1] |= SKEIN_T1_TREE_LEVEL(height); \
276	}
277
278/* ignore all asserts, for performance */
279#define skein_assert_ret(x, ret_code)
280#define skein_assert(x)
281
282/*****************************************************************
283** Skein block function constants (shared across Ref and Opt code)
284******************************************************************/
285enum {
286	    /* SKEIN_256 round rotation constants */
287	R_256_0_0 = 14, R_256_0_1 = 16,
288	R_256_1_0 = 52, R_256_1_1 = 57,
289	R_256_2_0 = 23, R_256_2_1 = 40,
290	R_256_3_0 =  5, R_256_3_1 = 37,
291	R_256_4_0 = 25, R_256_4_1 = 33,
292	R_256_5_0 = 46, R_256_5_1 = 12,
293	R_256_6_0 = 58, R_256_6_1 = 22,
294	R_256_7_0 = 32, R_256_7_1 = 32,
295
296	    /* SKEIN_512 round rotation constants */
297	R_512_0_0 = 46, R_512_0_1 = 36, R_512_0_2 = 19, R_512_0_3 = 37,
298	R_512_1_0 = 33, R_512_1_1 = 27, R_512_1_2 = 14, R_512_1_3 = 42,
299	R_512_2_0 = 17, R_512_2_1 = 49, R_512_2_2 = 36, R_512_2_3 = 39,
300	R_512_3_0 = 44, R_512_3_1 =  9, R_512_3_2 = 54, R_512_3_3 = 56,
301	R_512_4_0 = 39, R_512_4_1 = 30, R_512_4_2 = 34, R_512_4_3 = 24,
302	R_512_5_0 = 13, R_512_5_1 = 50, R_512_5_2 = 10, R_512_5_3 = 17,
303	R_512_6_0 = 25, R_512_6_1 = 29, R_512_6_2 = 39, R_512_6_3 = 43,
304	R_512_7_0 =  8, R_512_7_1 = 35, R_512_7_2 = 56, R_512_7_3 = 22,
305
306	    /* SKEIN_1024 round rotation constants */
307	R1024_0_0 = 24, R1024_0_1 = 13, R1024_0_2 =  8, R1024_0_3 = 47,
308	R1024_0_4 =  8, R1024_0_5 = 17, R1024_0_6 = 22, R1024_0_7 = 37,
309	R1024_1_0 = 38, R1024_1_1 = 19, R1024_1_2 = 10, R1024_1_3 = 55,
310	R1024_1_4 = 49, R1024_1_5 = 18, R1024_1_6 = 23, R1024_1_7 = 52,
311	R1024_2_0 = 33, R1024_2_1 =  4, R1024_2_2 = 51, R1024_2_3 = 13,
312	R1024_2_4 = 34, R1024_2_5 = 41, R1024_2_6 = 59, R1024_2_7 = 17,
313	R1024_3_0 =  5, R1024_3_1 = 20, R1024_3_2 = 48, R1024_3_3 = 41,
314	R1024_3_4 = 47, R1024_3_5 = 28, R1024_3_6 = 16, R1024_3_7 = 25,
315	R1024_4_0 = 41, R1024_4_1 =  9, R1024_4_2 = 37, R1024_4_3 = 31,
316	R1024_4_4 = 12, R1024_4_5 = 47, R1024_4_6 = 44, R1024_4_7 = 30,
317	R1024_5_0 = 16, R1024_5_1 = 34, R1024_5_2 = 56, R1024_5_3 = 51,
318	R1024_5_4 =  4, R1024_5_5 = 53, R1024_5_6 = 42, R1024_5_7 = 41,
319	R1024_6_0 = 31, R1024_6_1 = 44, R1024_6_2 = 47, R1024_6_3 = 46,
320	R1024_6_4 = 19, R1024_6_5 = 42, R1024_6_6 = 44, R1024_6_7 = 25,
321	R1024_7_0 =  9, R1024_7_1 = 48, R1024_7_2 = 35, R1024_7_3 = 52,
322	R1024_7_4 = 23, R1024_7_5 = 31, R1024_7_6 = 37, R1024_7_7 = 20
323};
324
325#ifndef SKEIN_ROUNDS
326#define SKEIN_256_ROUNDS_TOTAL (72)	/* # rounds for diff block sizes */
327#define SKEIN_512_ROUNDS_TOTAL (72)
328#define SKEIN_1024_ROUNDS_TOTAL (80)
329#else			/* allow command-line define in range 8*(5..14)   */
330#define SKEIN_256_ROUNDS_TOTAL (8*((((SKEIN_ROUNDS/100) + 5) % 10) + 5))
331#define SKEIN_512_ROUNDS_TOTAL (8*((((SKEIN_ROUNDS/10)  + 5) % 10) + 5))
332#define SKEIN_1024_ROUNDS_TOTAL (8*((((SKEIN_ROUNDS)     + 5) % 10) + 5))
333#endif
334
335#endif  /* ifndef _SKEIN_H_ */
336