1// Copyright (c) 2016 Alex Hultman and contributors
2
3// This software is provided 'as-is', without any express or implied
4// warranty. In no event will the authors be held liable for any damages
5// arising from the use of this software.
6
7// Permission is granted to anyone to use this software for any purpose,
8// including commercial applications, and to alter it and redistribute it
9// freely, subject to the following restrictions:
10
11// 1. The origin of this software must not be misrepresented; you must not
12// claim that you wrote the original software. If you use this software
13// in a product, an acknowledgement in the product documentation would be
14// appreciated but is not required.
15// 2. Altered source versions must be plainly marked as such, and must not be
16// misrepresented as being the original software.
17// 3. This notice may not be removed or altered from any source distribution.
18
19#pragma once
20
21#include <cstddef>
22#include <cstdint>
23#include <string.h>
24#include <string>
25
26class WebSocketHandshakeKeyGen
27{
28 template<int N, typename T>
29 struct static_for
30 {
31 void operator()(uint32_t* a, uint32_t* b)
32 {
33 static_for<N - 1, T>()(a, b);
34 T::template f<N - 1>(a, b);
35 }
36 };
37
38 template<typename T>
39 struct static_for<0, T>
40 {
41 void operator()(uint32_t* /*a*/, uint32_t* /*hash*/)
42 {
43 }
44 };
45
46 template<int state>
47 struct Sha1Loop
48 {
49 static inline uint32_t rol(uint32_t value, size_t bits)
50 {
51 return (value << bits) | (value >> (32 - bits));
52 }
53 static inline uint32_t blk(uint32_t b[16], size_t i)
54 {
55 return rol(b[(i + 13) & 15] ^ b[(i + 8) & 15] ^ b[(i + 2) & 15] ^ b[i], 1);
56 }
57
58 template<int i>
59 static inline void f(uint32_t* a, uint32_t* b)
60 {
61 switch (state)
62 {
63 case 1:
64 a[i % 5] +=
65 ((a[(3 + i) % 5] & (a[(2 + i) % 5] ^ a[(1 + i) % 5])) ^ a[(1 + i) % 5]) +
66 b[i] + 0x5a827999 + rol(a[(4 + i) % 5], 5);
67 a[(3 + i) % 5] = rol(a[(3 + i) % 5], 30);
68 break;
69 case 2:
70 b[i] = blk(b, i);
71 a[(1 + i) % 5] +=
72 ((a[(4 + i) % 5] & (a[(3 + i) % 5] ^ a[(2 + i) % 5])) ^ a[(2 + i) % 5]) +
73 b[i] + 0x5a827999 + rol(a[(5 + i) % 5], 5);
74 a[(4 + i) % 5] = rol(a[(4 + i) % 5], 30);
75 break;
76 case 3:
77 b[(i + 4) % 16] = blk(b, (i + 4) % 16);
78 a[i % 5] += (a[(3 + i) % 5] ^ a[(2 + i) % 5] ^ a[(1 + i) % 5]) +
79 b[(i + 4) % 16] + 0x6ed9eba1 + rol(a[(4 + i) % 5], 5);
80 a[(3 + i) % 5] = rol(a[(3 + i) % 5], 30);
81 break;
82 case 4:
83 b[(i + 8) % 16] = blk(b, (i + 8) % 16);
84 a[i % 5] += (((a[(3 + i) % 5] | a[(2 + i) % 5]) & a[(1 + i) % 5]) |
85 (a[(3 + i) % 5] & a[(2 + i) % 5])) +
86 b[(i + 8) % 16] + 0x8f1bbcdc + rol(a[(4 + i) % 5], 5);
87 a[(3 + i) % 5] = rol(a[(3 + i) % 5], 30);
88 break;
89 case 5:
90 b[(i + 12) % 16] = blk(b, (i + 12) % 16);
91 a[i % 5] += (a[(3 + i) % 5] ^ a[(2 + i) % 5] ^ a[(1 + i) % 5]) +
92 b[(i + 12) % 16] + 0xca62c1d6 + rol(a[(4 + i) % 5], 5);
93 a[(3 + i) % 5] = rol(a[(3 + i) % 5], 30);
94 break;
95 case 6: b[i] += a[4 - i];
96 }
97 }
98 };
99
100 static inline void sha1(uint32_t hash[5], uint32_t b[16])
101 {
102 uint32_t a[5] = {hash[4], hash[3], hash[2], hash[1], hash[0]};
103 static_for<16, Sha1Loop<1>>()(a, b);
104 static_for<4, Sha1Loop<2>>()(a, b);
105 static_for<20, Sha1Loop<3>>()(a, b);
106 static_for<20, Sha1Loop<4>>()(a, b);
107 static_for<20, Sha1Loop<5>>()(a, b);
108 static_for<5, Sha1Loop<6>>()(a, hash);
109 }
110
111 static inline void base64(unsigned char* src, char* dst)
112 {
113 const char* b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
114 for (int i = 0; i < 18; i += 3)
115 {
116 *dst++ = b64[(src[i] >> 2) & 63];
117 *dst++ = b64[((src[i] & 3) << 4) | ((src[i + 1] & 240) >> 4)];
118 *dst++ = b64[((src[i + 1] & 15) << 2) | ((src[i + 2] & 192) >> 6)];
119 *dst++ = b64[src[i + 2] & 63];
120 }
121 *dst++ = b64[(src[18] >> 2) & 63];
122 *dst++ = b64[((src[18] & 3) << 4) | ((src[19] & 240) >> 4)];
123 *dst++ = b64[((src[19] & 15) << 2)];
124 *dst++ = '=';
125 }
126
127public:
128 static inline void generate(const std::string& inputStr, char output[28])
129 {
130 char input[25] = {};
131 strncpy(input, inputStr.c_str(), 25 - 1);
132 input[25 - 1] = '\0';
133
134 uint32_t b_output[5] = {0x67452301, 0xefcdab89, 0x98badcfe, 0x10325476, 0xc3d2e1f0};
135 uint32_t b_input[16] = {0,
136 0,
137 0,
138 0,
139 0,
140 0,
141 0x32353845,
142 0x41464135,
143 0x2d453931,
144 0x342d3437,
145 0x44412d39,
146 0x3543412d,
147 0x43354142,
148 0x30444338,
149 0x35423131,
150 0x80000000};
151
152 for (int i = 0; i < 6; i++)
153 {
154 b_input[i] = (input[4 * i + 3] & 0xff) | (input[4 * i + 2] & 0xff) << 8 |
155 (input[4 * i + 1] & 0xff) << 16 | (input[4 * i + 0] & 0xff) << 24;
156 }
157 sha1(b_output, b_input);
158 uint32_t last_b[16] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 480};
159 sha1(b_output, last_b);
160 for (int i = 0; i < 5; i++)
161 {
162 uint32_t tmp = b_output[i];
163 char* bytes = (char*) &b_output[i];
164 bytes[3] = tmp & 0xff;
165 bytes[2] = (tmp >> 8) & 0xff;
166 bytes[1] = (tmp >> 16) & 0xff;
167 bytes[0] = (tmp >> 24) & 0xff;
168 }
169 base64((unsigned char*) b_output, output);
170 }
171};
172