1 /* md5sum.c - Calculate RFC 1321 md5 hash and sha1 hash.
2  *
3  * Copyright 2012 Rob Landley <rob@landley.net>
4  *
5  * See http://refspecs.linuxfoundation.org/LSB_4.1.0/LSB-Core-generic/LSB-Core-generic/md5sum.html
6  * and http://www.ietf.org/rfc/rfc1321.txt
7  *
8  * They're combined this way to share infrastructure, and because md5sum is
9  * and LSB standard command, sha1sum is just a good idea.
10 
11 USE_MD5SUM(NEWTOY(md5sum, "b", TOYFLAG_USR|TOYFLAG_BIN))
12 USE_SHA1SUM(NEWTOY(sha1sum, "b", TOYFLAG_USR|TOYFLAG_BIN))
13 
14 config MD5SUM
15   bool "md5sum"
16   default y
17   help
18     usage: md5sum [FILE]...
19 
20     Calculate md5 hash for each input file, reading from stdin if none.
21     Output one hash (16 hex digits) for each input file, followed by
22     filename.
23 
24     -b	brief (hash only, no filename)
25 
26 config SHA1SUM
27   bool "sha1sum"
28   default y
29   help
30     usage: sha1sum [FILE]...
31 
32     calculate sha1 hash for each input file, reading from stdin if none.
33     Output one hash (20 hex digits) for each input file, followed by
34     filename.
35 
36     -b	brief (hash only, no filename)
37 */
38 
39 #define FOR_md5sum
40 #include "toys.h"
41 
42 GLOBALS(
43   unsigned state[5];
44   unsigned oldstate[5];
45   uint64_t count;
46   union {
47     char c[64];
48     unsigned i[16];
49   } buffer;
50 )
51 
52 #define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))
53 
54 // for(i=0; i<64; i++) md5table[i] = abs(sin(i+1))*(1<<32);  But calculating
55 // that involves not just floating point but pulling in -lm (and arguing with
56 // C about whether 1<<32 is a valid thing to do on 32 bit platforms) so:
57 
58 static uint32_t md5table[64] = {
59   0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee, 0xf57c0faf, 0x4787c62a,
60   0xa8304613, 0xfd469501, 0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be,
61   0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821, 0xf61e2562, 0xc040b340,
62   0x265e5a51, 0xe9b6c7aa, 0xd62f105d, 0x02441453, 0xd8a1e681, 0xe7d3fbc8,
63   0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed, 0xa9e3e905, 0xfcefa3f8,
64   0x676f02d9, 0x8d2a4c8a, 0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c,
65   0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70, 0x289b7ec6, 0xeaa127fa,
66   0xd4ef3085, 0x04881d05, 0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665,
67   0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039, 0x655b59c3, 0x8f0ccc92,
68   0xffeff47d, 0x85845dd1, 0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1,
69   0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391
70 };
71 
72 static const uint8_t md5rot[64] = {
73   7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22,
74   5,  9, 14, 20, 5,  9, 14, 20, 5,  9, 14, 20, 5,  9, 14, 20,
75   4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23,
76   6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21
77 };
78 
79 // Mix next 64 bytes of data into md5 hash
80 
md5_transform(void)81 static void md5_transform(void)
82 {
83   unsigned x[4], *b = TT.buffer.i;
84   int i;
85 
86   memcpy(x, TT.state, sizeof(x));
87 
88   for (i=0; i<64; i++) {
89     unsigned int in, temp, swap;
90     if (i<16) {
91       in = i;
92       temp = x[1];
93       temp = (temp & x[2]) | ((~temp) & x[3]);
94     } else if (i<32) {
95       in = (1+(5*i))&15;
96       temp = x[3];
97       temp = (x[1] & temp) | (x[2] & ~temp);
98     } else if (i<48) {
99       in = (3*i+5)&15;
100       temp = x[1] ^ x[2] ^ x[3];
101     } else {
102       in = (7*i)&15;
103       temp = x[2] ^ (x[1] | ~x[3]);
104     }
105     temp += x[0] + b[in] + md5table[i];
106     swap = x[3];
107     x[3] = x[2];
108     x[2] = x[1];
109     x[1] += rol(temp, md5rot[i]);
110     x[0] = swap;
111   }
112   for (i=0; i<4; i++) TT.state[i] += x[i];
113 }
114 
115 // Mix next 64 bytes of data into sha1 hash.
116 
117 static const unsigned rconsts[]={0x5A827999,0x6ED9EBA1,0x8F1BBCDC,0xCA62C1D6};
118 
sha1_transform(void)119 static void sha1_transform(void)
120 {
121   int i, j, k, count;
122   unsigned *block = TT.buffer.i;
123   unsigned *rot[5], *temp;
124 
125   // Copy context->state[] to working vars
126   for (i=0; i<5; i++) {
127     TT.oldstate[i] = TT.state[i];
128     rot[i] = TT.state + i;
129   }
130   // 4 rounds of 20 operations each.
131   for (i=count=0; i<4; i++) {
132     for (j=0; j<20; j++) {
133       unsigned work;
134 
135       work = *rot[2] ^ *rot[3];
136       if (!i) work = (work & *rot[1]) ^ *rot[3];
137       else {
138         if (i==2) work = ((*rot[1]|*rot[2])&*rot[3])|(*rot[1]&*rot[2]);
139         else work ^= *rot[1];
140       }
141 
142       if (!i && j<16)
143         work += block[count] = (rol(block[count],24)&0xFF00FF00)
144                              | (rol(block[count],8)&0x00FF00FF);
145       else
146         work += block[count&15] = rol(block[(count+13)&15]
147               ^ block[(count+8)&15] ^ block[(count+2)&15] ^ block[count&15], 1);
148       *rot[4] += work + rol(*rot[0],5) + rconsts[i];
149       *rot[1] = rol(*rot[1],30);
150 
151       // Rotate by one for next time.
152       temp = rot[4];
153       for (k=4; k; k--) rot[k] = rot[k-1];
154       *rot = temp;
155       count++;
156     }
157   }
158   // Add the previous values of state[]
159   for (i=0; i<5; i++) TT.state[i] += TT.oldstate[i];
160 }
161 
162 // Fill the 64-byte working buffer and call transform() when full.
163 
hash_update(char * data,unsigned int len,void (* transform)(void))164 static void hash_update(char *data, unsigned int len, void (*transform)(void))
165 {
166   unsigned int i, j;
167 
168   j = TT.count & 63;
169   TT.count += len;
170 
171   for (;;) {
172     // Grab next chunk of data, return if it's not enough to process a frame
173     i = 64 - j;
174     if (i>len) i = len;
175     memcpy(TT.buffer.c+j, data, i);
176     if (j+i != 64) break;
177 
178     // Process a frame
179     if (IS_BIG_ENDIAN)
180       for (j=0; j<16; j++) TT.buffer.i[j] = SWAP_LE32(TT.buffer.i[j]);
181     transform();
182     j=0;
183     data += i;
184     len -= i;
185   }
186 }
187 
188 // Callback for loopfiles()
189 
do_hash(int fd,char * name)190 static void do_hash(int fd, char *name)
191 {
192   uint64_t count;
193   int i, sha1=toys.which->name[0]=='s';;
194   char buf;
195   void (*transform)(void);
196 
197   /* SHA1 initialization constants  (md5sum uses first 4) */
198   TT.state[0] = 0x67452301;
199   TT.state[1] = 0xEFCDAB89;
200   TT.state[2] = 0x98BADCFE;
201   TT.state[3] = 0x10325476;
202   TT.state[4] = 0xC3D2E1F0;
203   TT.count = 0;
204 
205   transform = sha1 ? sha1_transform : md5_transform;
206   for (;;) {
207     i = read(fd, toybuf, sizeof(toybuf));
208     if (i<1) break;
209     hash_update(toybuf, i, transform);
210   }
211 
212   count = TT.count << 3;
213 
214   // End the message by appending a "1" bit to the data, ending with the
215   // message size (in bits, big endian), and adding enough zero bits in
216   // between to pad to the end of the next 64-byte frame.
217   //
218   // Since our input up to now has been in whole bytes, we can deal with
219   // bytes here too.
220 
221   buf = 0x80;
222   do {
223     hash_update(&buf, 1, transform);
224     buf = 0;
225   } while ((TT.count & 63) != 56);
226   count = sha1 ? SWAP_BE64(count) : SWAP_LE64(count);
227   hash_update((void *)&count, 8, transform);
228 
229   if (sha1)
230     for (i = 0; i < 20; i++)
231       printf("%02x", 255&(TT.state[i>>2] >> ((3-(i & 3)) * 8)));
232   else for (i=0; i<4; i++) printf("%08x", bswap_32(TT.state[i]));
233 
234   // Wipe variables. Cryptographer paranoia.
235   memset(&TT, 0, sizeof(TT));
236 
237   printf((toys.optflags & FLAG_b) ? "\n" : "  %s\n", name);
238 }
239 
md5sum_main(void)240 void md5sum_main(void)
241 {
242   loopfiles(toys.optargs, do_hash);
243 }
244 
sha1sum_main(void)245 void sha1sum_main(void)
246 {
247   md5sum_main();
248 }
249