1 // Copyright 2014 The PDFium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
6
7 #include "core/fdrm/fx_crypt.h"
8
9 #include <utility>
10
11 #include "core/fxcrt/span_util.h"
12
13 #define GET_UINT32(n, b, i) \
14 { \
15 (n) = (uint32_t)((uint8_t*)b)[(i)] | \
16 (((uint32_t)((uint8_t*)b)[(i) + 1]) << 8) | \
17 (((uint32_t)((uint8_t*)b)[(i) + 2]) << 16) | \
18 (((uint32_t)((uint8_t*)b)[(i) + 3]) << 24); \
19 }
20 #define PUT_UINT32(n, b, i) \
21 { \
22 (((uint8_t*)b)[(i)]) = (uint8_t)(((n)) & 0xFF); \
23 (((uint8_t*)b)[(i) + 1]) = (uint8_t)(((n) >> 8) & 0xFF); \
24 (((uint8_t*)b)[(i) + 2]) = (uint8_t)(((n) >> 16) & 0xFF); \
25 (((uint8_t*)b)[(i) + 3]) = (uint8_t)(((n) >> 24) & 0xFF); \
26 }
27
28 namespace {
29
30 const uint8_t md5_padding[64] = {
31 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
32 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
33 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
34
md5_process(CRYPT_md5_context * ctx,const uint8_t data[64])35 void md5_process(CRYPT_md5_context* ctx, const uint8_t data[64]) {
36 uint32_t X[16];
37 GET_UINT32(X[0], data, 0);
38 GET_UINT32(X[1], data, 4);
39 GET_UINT32(X[2], data, 8);
40 GET_UINT32(X[3], data, 12);
41 GET_UINT32(X[4], data, 16);
42 GET_UINT32(X[5], data, 20);
43 GET_UINT32(X[6], data, 24);
44 GET_UINT32(X[7], data, 28);
45 GET_UINT32(X[8], data, 32);
46 GET_UINT32(X[9], data, 36);
47 GET_UINT32(X[10], data, 40);
48 GET_UINT32(X[11], data, 44);
49 GET_UINT32(X[12], data, 48);
50 GET_UINT32(X[13], data, 52);
51 GET_UINT32(X[14], data, 56);
52 GET_UINT32(X[15], data, 60);
53 uint32_t A = ctx->state[0];
54 uint32_t B = ctx->state[1];
55 uint32_t C = ctx->state[2];
56 uint32_t D = ctx->state[3];
57 #define S(x, n) ((x << n) | ((x & 0xFFFFFFFF) >> (32 - n)))
58 #define P(a, b, c, d, k, s, t) \
59 { \
60 a += F(b, c, d) + X[k] + t; \
61 a = S(a, s) + b; \
62 }
63 #define F(x, y, z) (z ^ (x & (y ^ z)))
64 P(A, B, C, D, 0, 7, 0xD76AA478);
65 P(D, A, B, C, 1, 12, 0xE8C7B756);
66 P(C, D, A, B, 2, 17, 0x242070DB);
67 P(B, C, D, A, 3, 22, 0xC1BDCEEE);
68 P(A, B, C, D, 4, 7, 0xF57C0FAF);
69 P(D, A, B, C, 5, 12, 0x4787C62A);
70 P(C, D, A, B, 6, 17, 0xA8304613);
71 P(B, C, D, A, 7, 22, 0xFD469501);
72 P(A, B, C, D, 8, 7, 0x698098D8);
73 P(D, A, B, C, 9, 12, 0x8B44F7AF);
74 P(C, D, A, B, 10, 17, 0xFFFF5BB1);
75 P(B, C, D, A, 11, 22, 0x895CD7BE);
76 P(A, B, C, D, 12, 7, 0x6B901122);
77 P(D, A, B, C, 13, 12, 0xFD987193);
78 P(C, D, A, B, 14, 17, 0xA679438E);
79 P(B, C, D, A, 15, 22, 0x49B40821);
80 #undef F
81 #define F(x, y, z) (y ^ (z & (x ^ y)))
82 P(A, B, C, D, 1, 5, 0xF61E2562);
83 P(D, A, B, C, 6, 9, 0xC040B340);
84 P(C, D, A, B, 11, 14, 0x265E5A51);
85 P(B, C, D, A, 0, 20, 0xE9B6C7AA);
86 P(A, B, C, D, 5, 5, 0xD62F105D);
87 P(D, A, B, C, 10, 9, 0x02441453);
88 P(C, D, A, B, 15, 14, 0xD8A1E681);
89 P(B, C, D, A, 4, 20, 0xE7D3FBC8);
90 P(A, B, C, D, 9, 5, 0x21E1CDE6);
91 P(D, A, B, C, 14, 9, 0xC33707D6);
92 P(C, D, A, B, 3, 14, 0xF4D50D87);
93 P(B, C, D, A, 8, 20, 0x455A14ED);
94 P(A, B, C, D, 13, 5, 0xA9E3E905);
95 P(D, A, B, C, 2, 9, 0xFCEFA3F8);
96 P(C, D, A, B, 7, 14, 0x676F02D9);
97 P(B, C, D, A, 12, 20, 0x8D2A4C8A);
98 #undef F
99 #define F(x, y, z) (x ^ y ^ z)
100 P(A, B, C, D, 5, 4, 0xFFFA3942);
101 P(D, A, B, C, 8, 11, 0x8771F681);
102 P(C, D, A, B, 11, 16, 0x6D9D6122);
103 P(B, C, D, A, 14, 23, 0xFDE5380C);
104 P(A, B, C, D, 1, 4, 0xA4BEEA44);
105 P(D, A, B, C, 4, 11, 0x4BDECFA9);
106 P(C, D, A, B, 7, 16, 0xF6BB4B60);
107 P(B, C, D, A, 10, 23, 0xBEBFBC70);
108 P(A, B, C, D, 13, 4, 0x289B7EC6);
109 P(D, A, B, C, 0, 11, 0xEAA127FA);
110 P(C, D, A, B, 3, 16, 0xD4EF3085);
111 P(B, C, D, A, 6, 23, 0x04881D05);
112 P(A, B, C, D, 9, 4, 0xD9D4D039);
113 P(D, A, B, C, 12, 11, 0xE6DB99E5);
114 P(C, D, A, B, 15, 16, 0x1FA27CF8);
115 P(B, C, D, A, 2, 23, 0xC4AC5665);
116 #undef F
117 #define F(x, y, z) (y ^ (x | ~z))
118 P(A, B, C, D, 0, 6, 0xF4292244);
119 P(D, A, B, C, 7, 10, 0x432AFF97);
120 P(C, D, A, B, 14, 15, 0xAB9423A7);
121 P(B, C, D, A, 5, 21, 0xFC93A039);
122 P(A, B, C, D, 12, 6, 0x655B59C3);
123 P(D, A, B, C, 3, 10, 0x8F0CCC92);
124 P(C, D, A, B, 10, 15, 0xFFEFF47D);
125 P(B, C, D, A, 1, 21, 0x85845DD1);
126 P(A, B, C, D, 8, 6, 0x6FA87E4F);
127 P(D, A, B, C, 15, 10, 0xFE2CE6E0);
128 P(C, D, A, B, 6, 15, 0xA3014314);
129 P(B, C, D, A, 13, 21, 0x4E0811A1);
130 P(A, B, C, D, 4, 6, 0xF7537E82);
131 P(D, A, B, C, 11, 10, 0xBD3AF235);
132 P(C, D, A, B, 2, 15, 0x2AD7D2BB);
133 P(B, C, D, A, 9, 21, 0xEB86D391);
134 #undef F
135 ctx->state[0] += A;
136 ctx->state[1] += B;
137 ctx->state[2] += C;
138 ctx->state[3] += D;
139 }
140
141 } // namespace
142
CRYPT_ArcFourSetup(CRYPT_rc4_context * context,pdfium::span<const uint8_t> key)143 void CRYPT_ArcFourSetup(CRYPT_rc4_context* context,
144 pdfium::span<const uint8_t> key) {
145 context->x = 0;
146 context->y = 0;
147 for (int i = 0; i < CRYPT_rc4_context::kPermutationLength; ++i)
148 context->m[i] = i;
149
150 int j = 0;
151 for (int i = 0; i < CRYPT_rc4_context::kPermutationLength; ++i) {
152 size_t size = key.size();
153 j = (j + context->m[i] + (size ? key[i % size] : 0)) & 0xFF;
154 std::swap(context->m[i], context->m[j]);
155 }
156 }
157
CRYPT_ArcFourCrypt(CRYPT_rc4_context * context,pdfium::span<uint8_t> data)158 void CRYPT_ArcFourCrypt(CRYPT_rc4_context* context,
159 pdfium::span<uint8_t> data) {
160 for (auto& datum : data) {
161 context->x = (context->x + 1) & 0xFF;
162 context->y = (context->y + context->m[context->x]) & 0xFF;
163 std::swap(context->m[context->x], context->m[context->y]);
164 datum ^=
165 context->m[(context->m[context->x] + context->m[context->y]) & 0xFF];
166 }
167 }
168
CRYPT_ArcFourCryptBlock(pdfium::span<uint8_t> data,pdfium::span<const uint8_t> key)169 void CRYPT_ArcFourCryptBlock(pdfium::span<uint8_t> data,
170 pdfium::span<const uint8_t> key) {
171 CRYPT_rc4_context s;
172 CRYPT_ArcFourSetup(&s, key);
173 CRYPT_ArcFourCrypt(&s, data);
174 }
175
CRYPT_MD5Start()176 CRYPT_md5_context CRYPT_MD5Start() {
177 CRYPT_md5_context context;
178 context.total[0] = 0;
179 context.total[1] = 0;
180 context.state[0] = 0x67452301;
181 context.state[1] = 0xEFCDAB89;
182 context.state[2] = 0x98BADCFE;
183 context.state[3] = 0x10325476;
184 return context;
185 }
186
CRYPT_MD5Update(CRYPT_md5_context * context,pdfium::span<const uint8_t> data)187 void CRYPT_MD5Update(CRYPT_md5_context* context,
188 pdfium::span<const uint8_t> data) {
189 if (data.empty())
190 return;
191
192 uint32_t left = (context->total[0] >> 3) & 0x3F;
193 uint32_t fill = 64 - left;
194 context->total[0] += data.size() << 3;
195 context->total[1] += data.size() >> 29;
196 context->total[0] &= 0xFFFFFFFF;
197 context->total[1] += context->total[0] < data.size() << 3;
198
199 const pdfium::span<uint8_t> buffer_span = pdfium::make_span(context->buffer);
200 if (left && data.size() >= fill) {
201 fxcrt::spancpy(buffer_span.subspan(left), data.first(fill));
202 md5_process(context, context->buffer);
203 data = data.subspan(fill);
204 left = 0;
205 }
206 while (data.size() >= 64) {
207 md5_process(context, data.data());
208 data = data.subspan(64);
209 }
210 if (!data.empty())
211 fxcrt::spancpy(buffer_span.subspan(left), data);
212 }
213
CRYPT_MD5Finish(CRYPT_md5_context * context,uint8_t digest[16])214 void CRYPT_MD5Finish(CRYPT_md5_context* context, uint8_t digest[16]) {
215 uint8_t msglen[8];
216 PUT_UINT32(context->total[0], msglen, 0);
217 PUT_UINT32(context->total[1], msglen, 4);
218 uint32_t last = (context->total[0] >> 3) & 0x3F;
219 uint32_t padn = (last < 56) ? (56 - last) : (120 - last);
220 CRYPT_MD5Update(context, pdfium::make_span(md5_padding).first(padn));
221 CRYPT_MD5Update(context, msglen);
222 PUT_UINT32(context->state[0], digest, 0);
223 PUT_UINT32(context->state[1], digest, 4);
224 PUT_UINT32(context->state[2], digest, 8);
225 PUT_UINT32(context->state[3], digest, 12);
226 }
227
CRYPT_MD5Generate(pdfium::span<const uint8_t> data,uint8_t digest[16])228 void CRYPT_MD5Generate(pdfium::span<const uint8_t> data, uint8_t digest[16]) {
229 CRYPT_md5_context ctx = CRYPT_MD5Start();
230 CRYPT_MD5Update(&ctx, data);
231 CRYPT_MD5Finish(&ctx, digest);
232 }
233