mavlink_sha256.h
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1 #pragma once
2 
3 /*
4  sha-256 implementation for MAVLink based on Heimdal sources, with
5  modifications to suit mavlink headers
6  */
7 /*
8  * Copyright (c) 1995 - 2001 Kungliga Tekniska Högskolan
9  * (Royal Institute of Technology, Stockholm, Sweden).
10  * All rights reserved.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  *
16  * 1. Redistributions of source code must retain the above copyright
17  * notice, this list of conditions and the following disclaimer.
18  *
19  * 2. Redistributions in binary form must reproduce the above copyright
20  * notice, this list of conditions and the following disclaimer in the
21  * documentation and/or other materials provided with the distribution.
22  *
23  * 3. Neither the name of the Institute nor the names of its contributors
24  * may be used to endorse or promote products derived from this software
25  * without specific prior written permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30  * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37  * SUCH DAMAGE.
38  */
39 
40 /*
41  allow implementation to provide their own sha256 with the same API
42 */
43 #ifndef HAVE_MAVLINK_SHA256
44 
45 #ifdef MAVLINK_USE_CXX_NAMESPACE
46 namespace mavlink {
47 #endif
48 
49 #ifndef MAVLINK_HELPER
50 #define MAVLINK_HELPER
51 #endif
52 
53 typedef struct {
54  uint32_t sz[2];
55  uint32_t counter[8];
56  union {
57  unsigned char save_bytes[64];
58  uint32_t save_u32[16];
59  } u;
61 
62 #define Ch(x,y,z) (((x) & (y)) ^ ((~(x)) & (z)))
63 #define Maj(x,y,z) (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)))
64 
65 #define ROTR(x,n) (((x)>>(n)) | ((x) << (32 - (n))))
66 
67 #define Sigma0(x) (ROTR(x,2) ^ ROTR(x,13) ^ ROTR(x,22))
68 #define Sigma1(x) (ROTR(x,6) ^ ROTR(x,11) ^ ROTR(x,25))
69 #define sigma0(x) (ROTR(x,7) ^ ROTR(x,18) ^ ((x)>>3))
70 #define sigma1(x) (ROTR(x,17) ^ ROTR(x,19) ^ ((x)>>10))
71 
72 #define A m->counter[0]
73 #define B m->counter[1]
74 #define C m->counter[2]
75 #define D m->counter[3]
76 #define E m->counter[4]
77 #define F m->counter[5]
78 #define G m->counter[6]
79 #define H m->counter[7]
80 
81 static const uint32_t mavlink_sha256_constant_256[64] = {
82  0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
83  0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
84  0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
85  0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
86  0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
87  0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
88  0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
89  0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
90  0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
91  0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
92  0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
93  0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
94  0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
95  0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
96  0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
97  0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
98 };
99 
101 {
102  m->sz[0] = 0;
103  m->sz[1] = 0;
104  A = 0x6a09e667;
105  B = 0xbb67ae85;
106  C = 0x3c6ef372;
107  D = 0xa54ff53a;
108  E = 0x510e527f;
109  F = 0x9b05688c;
110  G = 0x1f83d9ab;
111  H = 0x5be0cd19;
112 }
113 
114 static inline void mavlink_sha256_calc(mavlink_sha256_ctx *m, uint32_t *in)
115 {
116  uint32_t AA, BB, CC, DD, EE, FF, GG, HH;
117  uint32_t data[64];
118  int i;
119 
120  AA = A;
121  BB = B;
122  CC = C;
123  DD = D;
124  EE = E;
125  FF = F;
126  GG = G;
127  HH = H;
128 
129  for (i = 0; i < 16; ++i)
130  data[i] = in[i];
131  for (i = 16; i < 64; ++i)
132  data[i] = sigma1(data[i-2]) + data[i-7] +
133  sigma0(data[i-15]) + data[i - 16];
134 
135  for (i = 0; i < 64; i++) {
136  uint32_t T1, T2;
137 
138  T1 = HH + Sigma1(EE) + Ch(EE, FF, GG) + mavlink_sha256_constant_256[i] + data[i];
139  T2 = Sigma0(AA) + Maj(AA,BB,CC);
140 
141  HH = GG;
142  GG = FF;
143  FF = EE;
144  EE = DD + T1;
145  DD = CC;
146  CC = BB;
147  BB = AA;
148  AA = T1 + T2;
149  }
150 
151  A += AA;
152  B += BB;
153  C += CC;
154  D += DD;
155  E += EE;
156  F += FF;
157  G += GG;
158  H += HH;
159 }
160 
161 MAVLINK_HELPER void mavlink_sha256_update(mavlink_sha256_ctx *m, const void *v, uint32_t len)
162 {
163  const unsigned char *p = (const unsigned char *)v;
164  uint32_t old_sz = m->sz[0];
165  uint32_t offset;
166 
167  m->sz[0] += len * 8;
168  if (m->sz[0] < old_sz)
169  ++m->sz[1];
170  offset = (old_sz / 8) % 64;
171  while(len > 0){
172  uint32_t l = 64 - offset;
173  if (len < l) {
174  l = len;
175  }
176  memcpy(m->u.save_bytes + offset, p, l);
177  offset += l;
178  p += l;
179  len -= l;
180  if(offset == 64){
181  int i;
182  uint32_t current[16];
183  const uint32_t *u = m->u.save_u32;
184  for (i = 0; i < 16; i++){
185  const uint8_t *p1 = (const uint8_t *)&u[i];
186  uint8_t *p2 = (uint8_t *)&current[i];
187  p2[0] = p1[3];
188  p2[1] = p1[2];
189  p2[2] = p1[1];
190  p2[3] = p1[0];
191  }
192  mavlink_sha256_calc(m, current);
193  offset = 0;
194  }
195  }
196 }
197 
198 /*
199  get first 48 bits of final sha256 hash
200  */
202 {
203  unsigned char zeros[72];
204  unsigned offset = (m->sz[0] / 8) % 64;
205  unsigned int dstart = (120 - offset - 1) % 64 + 1;
206  uint8_t *p = (uint8_t *)&m->counter[0];
207 
208  *zeros = 0x80;
209  memset (zeros + 1, 0, sizeof(zeros) - 1);
210  zeros[dstart+7] = (m->sz[0] >> 0) & 0xff;
211  zeros[dstart+6] = (m->sz[0] >> 8) & 0xff;
212  zeros[dstart+5] = (m->sz[0] >> 16) & 0xff;
213  zeros[dstart+4] = (m->sz[0] >> 24) & 0xff;
214  zeros[dstart+3] = (m->sz[1] >> 0) & 0xff;
215  zeros[dstart+2] = (m->sz[1] >> 8) & 0xff;
216  zeros[dstart+1] = (m->sz[1] >> 16) & 0xff;
217  zeros[dstart+0] = (m->sz[1] >> 24) & 0xff;
218 
219  mavlink_sha256_update(m, zeros, dstart + 8);
220 
221  // this ordering makes the result consistent with taking the first
222  // 6 bytes of more conventional sha256 functions. It assumes
223  // little-endian ordering of m->counter
224  result[0] = p[3];
225  result[1] = p[2];
226  result[2] = p[1];
227  result[3] = p[0];
228  result[4] = p[7];
229  result[5] = p[6];
230 }
231 
232 // prevent conflicts with users of the header
233 #undef A
234 #undef B
235 #undef C
236 #undef D
237 #undef E
238 #undef F
239 #undef G
240 #undef H
241 #undef Ch
242 #undef ROTR
243 #undef Sigma0
244 #undef Sigma1
245 #undef sigma0
246 #undef sigma1
247 
248 #ifdef MAVLINK_USE_CXX_NAMESPACE
249 } // namespace mavlink
250 #endif
251 
252 #endif // HAVE_MAVLINK_SHA256


mavlink
Author(s): Lorenz Meier
autogenerated on Sun Jul 7 2019 03:22:07