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1.1 root 1: /* MD2C.C - RSA Data Security, Inc., MD2 message-digest algorithm
2: */
3:
1.1.1.2 ! root 4: /* Copyright (C) 1990-2, RSA Data Security, Inc. Created 1990. All
! 5: rights reserved.
1.1 root 6:
7: License to copy and use this software is granted for
8: non-commercial Internet Privacy-Enhanced Mail provided that it is
9: identified as the "RSA Data Security, Inc. MD2 Message Digest
10: Algorithm" in all material mentioning or referencing this software
11: or this function.
12:
13: RSA Data Security, Inc. makes no representations concerning either
14: the merchantability of this software or the suitability of this
15: software for any particular purpose. It is provided "as is"
16: without express or implied warranty of any kind.
17:
18: These notices must be retained in any copies of any part of this
19: documentation and/or software.
20: */
21:
22: #include "global.h"
23: #include "md2.h"
24:
25: static void MD2Transform PROTO_LIST
26: ((unsigned char [16], unsigned char [16], unsigned char [16]));
27: static void MD2_memcpy PROTO_LIST ((POINTER, POINTER, unsigned int));
28: static void MD2_memset PROTO_LIST ((POINTER, int, unsigned int));
29:
30: /* Permutation of 0..255 constructed from the digits of pi. It gives a
31: "random" nonlinear byte substitution operation.
32: */
33: static unsigned char PI_SUBST[256] = {
34: 41, 46, 67, 201, 162, 216, 124, 1, 61, 54, 84, 161, 236, 240, 6,
35: 19, 98, 167, 5, 243, 192, 199, 115, 140, 152, 147, 43, 217, 188,
36: 76, 130, 202, 30, 155, 87, 60, 253, 212, 224, 22, 103, 66, 111, 24,
37: 138, 23, 229, 18, 190, 78, 196, 214, 218, 158, 222, 73, 160, 251,
38: 245, 142, 187, 47, 238, 122, 169, 104, 121, 145, 21, 178, 7, 63,
39: 148, 194, 16, 137, 11, 34, 95, 33, 128, 127, 93, 154, 90, 144, 50,
40: 39, 53, 62, 204, 231, 191, 247, 151, 3, 255, 25, 48, 179, 72, 165,
41: 181, 209, 215, 94, 146, 42, 172, 86, 170, 198, 79, 184, 56, 210,
42: 150, 164, 125, 182, 118, 252, 107, 226, 156, 116, 4, 241, 69, 157,
43: 112, 89, 100, 113, 135, 32, 134, 91, 207, 101, 230, 45, 168, 2, 27,
44: 96, 37, 173, 174, 176, 185, 246, 28, 70, 97, 105, 52, 64, 126, 15,
45: 85, 71, 163, 35, 221, 81, 175, 58, 195, 92, 249, 206, 186, 197,
46: 234, 38, 44, 83, 13, 110, 133, 40, 132, 9, 211, 223, 205, 244, 65,
47: 129, 77, 82, 106, 220, 55, 200, 108, 193, 171, 250, 36, 225, 123,
48: 8, 12, 189, 177, 74, 120, 136, 149, 139, 227, 99, 232, 109, 233,
49: 203, 213, 254, 59, 0, 29, 57, 242, 239, 183, 14, 102, 88, 208, 228,
50: 166, 119, 114, 248, 235, 117, 75, 10, 49, 68, 80, 180, 143, 237,
51: 31, 26, 219, 153, 141, 51, 159, 17, 131, 20
52: };
53:
54: static unsigned char *PADDING[] = {
1.1.1.2 ! root 55: (unsigned char *)"",
! 56: (unsigned char *)"\001",
! 57: (unsigned char *)"\002\002",
! 58: (unsigned char *)"\003\003\003",
! 59: (unsigned char *)"\004\004\004\004",
1.1 root 60: (unsigned char *)"\005\005\005\005\005",
61: (unsigned char *)"\006\006\006\006\006\006",
62: (unsigned char *)"\007\007\007\007\007\007\007",
63: (unsigned char *)"\010\010\010\010\010\010\010\010",
64: (unsigned char *)"\011\011\011\011\011\011\011\011\011",
65: (unsigned char *)"\012\012\012\012\012\012\012\012\012\012",
66: (unsigned char *)"\013\013\013\013\013\013\013\013\013\013\013",
67: (unsigned char *)"\014\014\014\014\014\014\014\014\014\014\014\014",
1.1.1.2 ! root 68: (unsigned char *)
! 69: "\015\015\015\015\015\015\015\015\015\015\015\015\015",
! 70: (unsigned char *)
! 71: "\016\016\016\016\016\016\016\016\016\016\016\016\016\016",
1.1 root 72: (unsigned char *)
73: "\017\017\017\017\017\017\017\017\017\017\017\017\017\017\017",
74: (unsigned char *)
75: "\020\020\020\020\020\020\020\020\020\020\020\020\020\020\020\020"
76: };
77:
78: /* MD2 initialization. Begins an MD2 operation, writing a new context.
79: */
80: void MD2Init (context)
1.1.1.2 ! root 81: MD2_CTX *context; /* context */
1.1 root 82: {
83: context->count = 0;
84: MD2_memset ((POINTER)context->state, 0, sizeof (context->state));
1.1.1.2 ! root 85: MD2_memset
! 86: ((POINTER)context->checksum, 0, sizeof (context->checksum));
1.1 root 87: }
88:
1.1.1.2 ! root 89: /* MD2 block update operation. Continues an MD2 message-digest
! 90: operation, processing another message block, and updating the
! 91: context.
1.1 root 92: */
93: void MD2Update (context, input, inputLen)
1.1.1.2 ! root 94: MD2_CTX *context; /* context */
! 95: unsigned char *input; /* input block */
! 96: unsigned int inputLen; /* length of input block */
1.1 root 97: {
98: unsigned int i, index, partLen;
99:
100: /* Update number of bytes mod 16 */
101: index = context->count;
102: context->count = (index + inputLen) & 0xf;
103:
104: partLen = 16 - index;
105:
106: /* Transform as many times as possible.
107: */
108: if (inputLen >= partLen) {
1.1.1.2 ! root 109: MD2_memcpy
! 110: ((POINTER)&context->buffer[index], (POINTER)input, partLen);
1.1 root 111: MD2Transform (context->state, context->checksum, context->buffer);
112:
113: for (i = partLen; i + 15 < inputLen; i += 16)
114: MD2Transform (context->state, context->checksum, &input[i]);
115:
116: index = 0;
117: }
118: else
119: i = 0;
120:
121: /* Buffer remaining input */
122: MD2_memcpy
1.1.1.2 ! root 123: ((POINTER)&context->buffer[index], (POINTER)&input[i],
! 124: inputLen-i);
1.1 root 125: }
126:
127: /* MD2 finalization. Ends an MD2 message-digest operation, writing the
128: message digest and zeroizing the context.
129: */
130: void MD2Final (digest, context)
1.1.1.2 ! root 131: unsigned char digest[16]; /* message digest */
! 132: MD2_CTX *context; /* context */
1.1 root 133: {
134: unsigned int index, padLen;
135:
136: /* Pad out to multiple of 16.
137: */
138: index = context->count;
139: padLen = 16 - index;
140: MD2Update (context, PADDING[padLen], padLen);
141:
142: /* Extend with checksum */
143: MD2Update (context, context->checksum, 16);
144:
145: /* Store state in digest */
146: MD2_memcpy ((POINTER)digest, (POINTER)context->state, 16);
147:
148: /* Zeroize sensitive information.
149: */
150: MD2_memset ((POINTER)context, 0, sizeof (*context));
151: }
152:
153: /* MD2 basic transformation. Transforms state and updates checksum
154: based on block.
155: */
156: static void MD2Transform (state, checksum, block)
157: unsigned char state[16];
158: unsigned char checksum[16];
159: unsigned char block[16];
160: {
161: unsigned int i, j, t;
162: unsigned char x[48];
163:
164: /* Form encryption block from state, block, state ^ block.
165: */
1.1.1.2 ! root 166: MD2_memcpy ((POINTER)x, (POINTER)state, 16);
! 167: MD2_memcpy ((POINTER)x+16, (POINTER)block, 16);
! 168: for (i = 0; i < 16; i++)
1.1 root 169: x[i+32] = state[i] ^ block[i];
170:
171: /* Encrypt block (18 rounds).
172: */
173: t = 0;
174: for (i = 0; i < 18; i++) {
175: for (j = 0; j < 48; j++)
176: t = x[j] ^= PI_SUBST[t];
177: t = (t + i) & 0xff;
178: }
179:
180: /* Save new state */
1.1.1.2 ! root 181: MD2_memcpy ((POINTER)state, (POINTER)x, 16);
1.1 root 182:
183: /* Update checksum.
184: */
185: t = checksum[15];
186: for (i = 0; i < 16; i++)
187: t = checksum[i] ^= PI_SUBST[block[i] ^ t];
188:
189: /* Zeroize sensitive information.
190: */
191: MD2_memset ((POINTER)x, 0, sizeof (x));
192: }
193:
194: /* Note: Replace "for loop" with standard memcpy if possible.
195: */
196: static void MD2_memcpy (output, input, len)
197: POINTER output;
198: POINTER input;
199: unsigned int len;
200: {
201: unsigned int i;
202:
203: for (i = 0; i < len; i++)
204: output[i] = input[i];
205: }
206:
207: /* Note: Replace "for loop" with standard memset if possible.
208: */
209: static void MD2_memset (output, value, len)
210: POINTER output;
211: int value;
212: unsigned int len;
213: {
214: unsigned int i;
215:
216: for (i = 0; i < len; i++)
217: ((char *)output)[i] = (char)value;
218: }
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