1//============================================================================
2//
3// SSSS tt lll lll
4// SS SS tt ll ll
5// SS tttttt eeee ll ll aaaa
6// SSSS tt ee ee ll ll aa
7// SS tt eeeeee ll ll aaaaa -- "An Atari 2600 VCS Emulator"
8// SS SS tt ee ll ll aa aa
9// SSSS ttt eeeee llll llll aaaaa
10//
11// Copyright (c) 1995-2019 by Bradford W. Mott, Stephen Anthony
12// and the Stella Team
13//
14// This file is derived from the RSA Data Security, Inc. MD5 Message-Digest
15// Algorithm. See the header below for copyright information.
16//
17// See the file "License.txt" for information on usage and redistribution of
18// this file, and for a DISCLAIMER OF ALL WARRANTIES.
19//============================================================================
20
21#include "FSNode.hxx"
22#include "MD5.hxx"
23
24/*
25 Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
26 rights reserved.
27
28 License to copy and use this software is granted provided that it
29 is identified as the "RSA Data Security, Inc. MD5 Message-Digest
30 Algorithm" in all material mentioning or referencing this software
31 or this function.
32
33 License is also granted to make and use derivative works provided
34 that such works are identified as "derived from the RSA Data
35 Security, Inc. MD5 Message-Digest Algorithm" in all material
36 mentioning or referencing the derived work.
37
38 RSA Data Security, Inc. makes no representations concerning either
39 the merchantability of this software or the suitability of this
40 software for any particular purpose. It is provided "as is"
41 without express or implied warranty of any kind.
42
43 These notices must be retained in any copies of any part of this
44 documentation and/or software.
45*/
46
47namespace MD5 {
48
49// Setup the types used by the MD5 routines
50using POINTER = uInt8*;
51
52// MD5 context.
53struct MD5_CTX
54{
55 uInt32 state[4]; /* state (ABCD) */
56 uInt32 count[2]; /* number of bits, modulo 2^64 (lsb first) */
57 uInt8 buffer[64]; /* input buffer */
58};
59
60// Constants for MD5Transform routine.
61#define S11 7
62#define S12 12
63#define S13 17
64#define S14 22
65#define S21 5
66#define S22 9
67#define S23 14
68#define S24 20
69#define S31 4
70#define S32 11
71#define S33 16
72#define S34 23
73#define S41 6
74#define S42 10
75#define S43 15
76#define S44 21
77
78static void MD5Init(MD5_CTX*);
79static void MD5Update(MD5_CTX*, const uInt8*, uInt32);
80static void MD5Final(uInt8[16], MD5_CTX*);
81static void MD5Transform(uInt32 [4], const uInt8 [64]);
82static void Encode(uInt8*, uInt32*, uInt32);
83static void Decode(uInt32*, const uInt8*, uInt32);
84
85static uInt8 PADDING[64] = {
86 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
87 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
88 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
89};
90
91// F, G, H and I are basic MD5 functions.
92#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
93#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
94#define H(x, y, z) ((x) ^ (y) ^ (z))
95#define I(x, y, z) ((y) ^ ((x) | (~z)))
96
97// ROTATE_LEFT rotates x left n bits.
98#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
99
100// FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
101// Rotation is separate from addition to prevent recomputation.
102#define FF(a, b, c, d, x, s, ac) { \
103 (a) += F ((b), (c), (d)) + (x) + uInt32(ac); \
104 (a) = ROTATE_LEFT ((a), (s)); \
105 (a) += (b); \
106 }
107#define GG(a, b, c, d, x, s, ac) { \
108 (a) += G ((b), (c), (d)) + (x) + uInt32(ac); \
109 (a) = ROTATE_LEFT ((a), (s)); \
110 (a) += (b); \
111 }
112#define HH(a, b, c, d, x, s, ac) { \
113 (a) += H ((b), (c), (d)) + (x) + uInt32(ac); \
114 (a) = ROTATE_LEFT ((a), (s)); \
115 (a) += (b); \
116 }
117#define II(a, b, c, d, x, s, ac) { \
118 (a) += I ((b), (c), (d)) + (x) + uInt32(ac); \
119 (a) = ROTATE_LEFT ((a), (s)); \
120 (a) += (b); \
121 }
122
123// MD5 initialization. Begins an MD5 operation, writing a new context.
124static void MD5Init(MD5_CTX* context)
125{
126 context->count[0] = context->count[1] = 0;
127 /* Load magic initialization constants. */
128 context->state[0] = 0x67452301;
129 context->state[1] = 0xefcdab89;
130 context->state[2] = 0x98badcfe;
131 context->state[3] = 0x10325476;
132}
133
134// MD5 block update operation. Continues an MD5 message-digest
135// operation, processing another message block, and updating the
136// context.
137static void MD5Update(MD5_CTX* context, const uInt8* input,
138 uInt32 inputLen)
139{
140 uInt32 i, index, partLen;
141
142 /* Compute number of bytes mod 64 */
143 index = uInt32((context->count[0] >> 3) & 0x3F);
144
145 /* Update number of bits */
146 if ((context->count[0] += (uInt32(inputLen) << 3))
147 < (uInt32(inputLen) << 3))
148 context->count[1]++;
149 context->count[1] += (uInt32(inputLen) >> 29);
150
151 partLen = 64 - index;
152
153 /* Transform as many times as possible. */
154 if (inputLen >= partLen) {
155 memcpy (const_cast<POINTER>(&context->buffer[index]),
156 const_cast<POINTER>(input), partLen);
157 MD5Transform (context->state, context->buffer);
158
159 for (i = partLen; i + 63 < inputLen; i += 64)
160 MD5Transform (context->state, &input[i]);
161
162 index = 0;
163 }
164 else
165 i = 0;
166
167 /* Buffer remaining input */
168 memcpy(const_cast<POINTER>(&context->buffer[index]),
169 const_cast<POINTER>(&input[i]), inputLen-i);
170}
171
172// MD5 finalization. Ends an MD5 message-digest operation, writing the
173// the message digest and zeroizing the context.
174static void MD5Final(uInt8 digest[16], MD5_CTX* context)
175{
176 uInt8 bits[8];
177 uInt32 index, padLen;
178
179 /* Save number of bits */
180 Encode (bits, context->count, 8);
181
182 /* Pad out to 56 mod 64. */
183 index = uInt32((context->count[0] >> 3) & 0x3f);
184 padLen = (index < 56) ? (56 - index) : (120 - index);
185 MD5Update (context, PADDING, padLen);
186
187 /* Append length (before padding) */
188 MD5Update (context, bits, 8);
189 /* Store state in digest */
190 Encode (digest, context->state, 16);
191
192 /* Zeroize sensitive information. */
193 memset (reinterpret_cast<POINTER>(context), 0, sizeof(*context));
194}
195
196// MD5 basic transformation. Transforms state based on block.
197static void MD5Transform(uInt32 state[4], const uInt8 block[64])
198{
199 uInt32 a = state[0], b = state[1], c = state[2], d = state[3], x[16];
200
201 Decode (x, block, 64);
202
203 /* Round 1 */
204 FF (a, b, c, d, x[ 0], S11, 0xd76aa478) /* 1 */
205 FF (d, a, b, c, x[ 1], S12, 0xe8c7b756) /* 2 */
206 FF (c, d, a, b, x[ 2], S13, 0x242070db) /* 3 */
207 FF (b, c, d, a, x[ 3], S14, 0xc1bdceee) /* 4 */
208 FF (a, b, c, d, x[ 4], S11, 0xf57c0faf) /* 5 */
209 FF (d, a, b, c, x[ 5], S12, 0x4787c62a) /* 6 */
210 FF (c, d, a, b, x[ 6], S13, 0xa8304613) /* 7 */
211 FF (b, c, d, a, x[ 7], S14, 0xfd469501) /* 8 */
212 FF (a, b, c, d, x[ 8], S11, 0x698098d8) /* 9 */
213 FF (d, a, b, c, x[ 9], S12, 0x8b44f7af) /* 10 */
214 FF (c, d, a, b, x[10], S13, 0xffff5bb1) /* 11 */
215 FF (b, c, d, a, x[11], S14, 0x895cd7be) /* 12 */
216 FF (a, b, c, d, x[12], S11, 0x6b901122) /* 13 */
217 FF (d, a, b, c, x[13], S12, 0xfd987193) /* 14 */
218 FF (c, d, a, b, x[14], S13, 0xa679438e) /* 15 */
219 FF (b, c, d, a, x[15], S14, 0x49b40821) /* 16 */
220
221 /* Round 2 */
222 GG (a, b, c, d, x[ 1], S21, 0xf61e2562) /* 17 */
223 GG (d, a, b, c, x[ 6], S22, 0xc040b340) /* 18 */
224 GG (c, d, a, b, x[11], S23, 0x265e5a51) /* 19 */
225 GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa) /* 20 */
226 GG (a, b, c, d, x[ 5], S21, 0xd62f105d) /* 21 */
227 GG (d, a, b, c, x[10], S22, 0x2441453) /* 22 */
228 GG (c, d, a, b, x[15], S23, 0xd8a1e681) /* 23 */
229 GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8) /* 24 */
230 GG (a, b, c, d, x[ 9], S21, 0x21e1cde6) /* 25 */
231 GG (d, a, b, c, x[14], S22, 0xc33707d6) /* 26 */
232 GG (c, d, a, b, x[ 3], S23, 0xf4d50d87) /* 27 */
233 GG (b, c, d, a, x[ 8], S24, 0x455a14ed) /* 28 */
234 GG (a, b, c, d, x[13], S21, 0xa9e3e905) /* 29 */
235 GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8) /* 30 */
236 GG (c, d, a, b, x[ 7], S23, 0x676f02d9) /* 31 */
237 GG (b, c, d, a, x[12], S24, 0x8d2a4c8a) /* 32 */
238
239 /* Round 3 */
240 HH (a, b, c, d, x[ 5], S31, 0xfffa3942) /* 33 */
241 HH (d, a, b, c, x[ 8], S32, 0x8771f681) /* 34 */
242 HH (c, d, a, b, x[11], S33, 0x6d9d6122) /* 35 */
243 HH (b, c, d, a, x[14], S34, 0xfde5380c) /* 36 */
244 HH (a, b, c, d, x[ 1], S31, 0xa4beea44) /* 37 */
245 HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9) /* 38 */
246 HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60) /* 39 */
247 HH (b, c, d, a, x[10], S34, 0xbebfbc70) /* 40 */
248 HH (a, b, c, d, x[13], S31, 0x289b7ec6) /* 41 */
249 HH (d, a, b, c, x[ 0], S32, 0xeaa127fa) /* 42 */
250 HH (c, d, a, b, x[ 3], S33, 0xd4ef3085) /* 43 */
251 HH (b, c, d, a, x[ 6], S34, 0x4881d05) /* 44 */
252 HH (a, b, c, d, x[ 9], S31, 0xd9d4d039) /* 45 */
253 HH (d, a, b, c, x[12], S32, 0xe6db99e5) /* 46 */
254 HH (c, d, a, b, x[15], S33, 0x1fa27cf8) /* 47 */
255 HH (b, c, d, a, x[ 2], S34, 0xc4ac5665) /* 48 */
256
257 /* Round 4 */
258 II (a, b, c, d, x[ 0], S41, 0xf4292244) /* 49 */
259 II (d, a, b, c, x[ 7], S42, 0x432aff97) /* 50 */
260 II (c, d, a, b, x[14], S43, 0xab9423a7) /* 51 */
261 II (b, c, d, a, x[ 5], S44, 0xfc93a039) /* 52 */
262 II (a, b, c, d, x[12], S41, 0x655b59c3) /* 53 */
263 II (d, a, b, c, x[ 3], S42, 0x8f0ccc92) /* 54 */
264 II (c, d, a, b, x[10], S43, 0xffeff47d) /* 55 */
265 II (b, c, d, a, x[ 1], S44, 0x85845dd1) /* 56 */
266 II (a, b, c, d, x[ 8], S41, 0x6fa87e4f) /* 57 */
267 II (d, a, b, c, x[15], S42, 0xfe2ce6e0) /* 58 */
268 II (c, d, a, b, x[ 6], S43, 0xa3014314) /* 59 */
269 II (b, c, d, a, x[13], S44, 0x4e0811a1) /* 60 */
270 II (a, b, c, d, x[ 4], S41, 0xf7537e82) /* 61 */
271 II (d, a, b, c, x[11], S42, 0xbd3af235) /* 62 */
272 II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb) /* 63 */
273 II (b, c, d, a, x[ 9], S44, 0xeb86d391) /* 64 */
274
275 state[0] += a;
276 state[1] += b;
277 state[2] += c;
278 state[3] += d;
279
280 /* Zeroize sensitive information. */
281 memset (reinterpret_cast<POINTER>(x), 0, sizeof(x));
282}
283
284// Encodes input (uInt32) into output (uInt8). Assumes len is
285// a multiple of 4.
286static void Encode(uInt8* output, uInt32* input, uInt32 len)
287{
288 uInt32 i, j;
289
290 for (i = 0, j = 0; j < len; ++i, j += 4) {
291 output[j] = uInt8(input[i] & 0xff);
292 output[j+1] = uInt8((input[i] >> 8) & 0xff);
293 output[j+2] = uInt8((input[i] >> 16) & 0xff);
294 output[j+3] = uInt8((input[i] >> 24) & 0xff);
295 }
296}
297
298// Decodes input (uInt8) into output (uInt32). Assumes len is
299// a multiple of 4.
300static void Decode(uInt32* output, const uInt8* input, uInt32 len)
301{
302 uInt32 i, j;
303
304 for (i = 0, j = 0; j < len; ++i, j += 4)
305 output[i] = (uInt32(input[j])) | ((uInt32(input[j+1])) << 8) |
306 ((uInt32(input[j+2])) << 16) | ((uInt32(input[j+3])) << 24);
307}
308
309// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
310string hash(const ByteBuffer& buffer, uInt32 length)
311{
312 return hash(buffer.get(), length);
313}
314
315// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
316string hash(const uInt8* buffer, uInt32 length)
317{
318 char hex[] = "0123456789abcdef";
319 MD5_CTX context;
320 uInt8 md5[16];
321
322 MD5Init(&context);
323 MD5Update(&context, buffer, length);
324 MD5Final(md5, &context);
325
326 string result;
327 for(int t = 0; t < 16; ++t)
328 {
329 result += hex[(md5[t] >> 4) & 0x0f];
330 result += hex[md5[t] & 0x0f];
331 }
332
333 return result;
334}
335
336// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
337string hash(const FilesystemNode& node)
338{
339 ByteBuffer image;
340 uInt32 size = 0;
341 try
342 {
343 size = node.read(image);
344 }
345 catch(...)
346 {
347 return EmptyString;
348 }
349
350 const string& md5 = hash(image, size);
351 return md5;
352}
353
354} // Namespace MD5
355