1 #include "os.h"
2 #include "mp.h"
3 #include "libsec.h"
4
5 #define KEYLEN 52
6
7 #define MODA 0x10000
8 #define MODM 0x10001
9 #define MASKA (MODA-1)
10
11 #define OP1(x, y) ((x) ^ (y))
12 #define OP2(x, y) (((x) + (y)) & MASKA)
13 #define OP3(x, y) mod(x, y)
14
15 #define OP2INV(x) (-(x))
16 #define OP3INV(x) inv(x)
17
18 #define BIGEND(k, i) ((k[i]<<8)|k[i+1])
19 #define MSB(x) ((x)>>8)
20 #define LSB(x) ((x)&0xff)
21
22 static ushort
mod(ushort x,ushort y)23 mod(ushort x, ushort y)
24 {
25 ushort q, r;
26 uint z;
27
28 if (x == 0)
29 return 1-y;
30 if (y == 0)
31 return 1-x;
32 z = (uint)x*(uint)y;
33 q = z >> 16;
34 r = z & MASKA;
35 return r-q+(r<q);
36 }
37
38 static ushort
inv(ushort x)39 inv(ushort x)
40 {
41 int q, r0, r1, r2, v0, v1, v2;
42
43 if (x <= 1)
44 return x;
45 r0 = MODM;
46 r1 = x;
47 v0 = 0;
48 v1 = 1;
49 while (r1 != 0) {
50 q = r0/r1;
51 r2 = r0-q*r1;
52 v2 = v0-q*v1;
53 r0 = r1;
54 r1 = r2;
55 v0 = v1;
56 v1 = v2;
57 }
58 if (v0 < 0)
59 v0 += MODM;
60 return v0 & MASKA;
61 }
62
63 static void
idea_key_setup_decrypt(ushort ek[KEYLEN],ushort dk[KEYLEN])64 idea_key_setup_decrypt(ushort ek[KEYLEN], ushort dk[KEYLEN])
65 {
66 int i;
67
68 for (i = 0; i < 54; i += 6) {
69 dk[i] = OP3INV(ek[48-i]);
70 dk[i+1] = OP2INV(ek[50-i]);
71 dk[i+2] = OP2INV(ek[49-i]);
72 dk[i+3] = OP3INV(ek[51-i]);
73 if (i < 48) {
74 dk[i+4] = ek[46-i];
75 dk[i+5] = ek[47-i];
76 }
77 }
78 }
79
80 void
idea_key_setup(uchar key[16],ushort ek[2* KEYLEN])81 idea_key_setup(uchar key[16], ushort ek[2*KEYLEN])
82 {
83 int i, j;
84 ushort tmp, *e = ek;
85
86 for (i = 0; i < 8; i++)
87 ek[i] = BIGEND(key, 2*i);
88 for (i = 8, j = 1; i < KEYLEN; i++, j++) {
89 ek[i] = (e[j&7]<<9)|(e[(j+1)&7]>>7);
90 if (((i+1) & 7) == 0)
91 e += 8;
92 }
93 tmp = ek[49];
94 ek[49] = ek[50];
95 ek[50] = tmp;
96 idea_key_setup_decrypt(ek, &ek[KEYLEN]);
97 }
98
99 void
idea_cipher(ushort key[2* KEYLEN],uchar text[8],int decrypting)100 idea_cipher(ushort key[2*KEYLEN], uchar text[8], int decrypting)
101 {
102 int i;
103 ushort *k;
104 ushort x[4];
105 ushort tmp, yout, zout;
106
107 k = decrypting ? &key[KEYLEN] : key;
108 for (i = 0; i < 4; i++)
109 x[i] = BIGEND(text, 2*i);
110 for (i = 0; i < 17; i++) {
111 if (!(i&1)) { /* odd round */
112 x[0] = OP3(x[0], k[3*i]);
113 tmp = OP2(x[2], k[3*i+2]);
114 x[2] = OP2(x[1], k[3*i+1]);
115 x[3] = OP3(x[3], k[3*i+3]);
116 x[1] = tmp;
117 }
118 else {
119 tmp = OP3(k[3*i+1], OP1(x[0], x[1]));
120 yout = OP3(OP2(tmp, OP1(x[2], x[3])), k[3*i+2]);
121 zout = OP2(tmp, yout);
122 x[0] = OP1(x[0], yout);
123 x[1] = OP1(x[1], yout);
124 x[2] = OP1(x[2], zout);
125 x[3] = OP1(x[3], zout);
126 }
127 }
128 for (i = 0; i < 4; i++) {
129 text[2*i] = MSB(x[i]);
130 text[2*i+1] = LSB(x[i]);
131 }
132 }
133
134 void
setupIDEAstate(IDEAstate * s,uchar key[16],uchar * ivec)135 setupIDEAstate(IDEAstate *s, uchar key[16], uchar *ivec)
136 {
137 memset(s, 0, sizeof(*s));
138 memmove(s->key, key, sizeof(s->key));
139 idea_key_setup(key, s->edkey);
140 if(ivec)
141 memmove(s->ivec, ivec, 8);
142 }
143
144 /*
145 void
146 main()
147 {
148 uchar key[] = { 0x00, 0x01, 0x00, 0x02, 0x00, 0x03, 0x00, 0x04,
149 0x00, 0x05, 0x00, 0x06, 0x00, 0x07, 0x00, 0x08 };
150 uchar plain[] = { 0x00, 0x00, 0x00, 0x01, 0x00, 0x02, 0x00, 0x03 };
151 uchar cipher[] = { 0x11, 0xFB, 0xED, 0x2B, 0x01, 0x98, 0x6D, 0xE5 };
152 ushort edkey[2*KEYLEN];
153 uchar tmp[8];
154
155 memcpy(tmp, plain, 8);
156 idea_key_setup(key, edkey);
157 idea_cipher(edkey, tmp, 0);
158 if (memcmp(tmp, cipher, 8)) {
159 print("encrypt wrong\n");
160 exits("");
161 }
162 idea_cipher(edkey, tmp, 1);
163 if (memcmp(tmp, plain, 8)) {
164 print("decrypt wrong\n");
165 exits("");
166 }
167 }
168 */
169