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发信人: Lg (创造人生的传奇), 信区: Linux
标 题: [转载] md2.c
发信站: BBS 荔园晨风站 (Fri Jan 21 23:09:03 2000), 站内信件
【 以下文字转载自 Hacker 讨论区 】
【 原文由 bstone 所发表 】
发信人: cloudsky (小四), 信区: Security
标 题: md2.c
发信站: 武汉白云黄鹤站 (Tue Jan 11 16:53:35 2000), 站内信件
/*
* md2.c
*
* signature function hook for MD2 (the RSA Data Security, Inc. MD2
* Message Digesting Algorithm) for Tripwire.
*
* The original MD2 code is contained in md2.c in its entirety.
*
* Gene Kim
* Purdue University
* September 27, 1992
* Revised by Wang,D.B.,Dec,17,1999.
*/
#include <stdio.h>
#include <sys/types.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <fcntl.h>
#include <string.h>
#define BUFSIZE 4096
#define SIG_MAX_LEN 200
typedef unsigned char *POINTER;
typedef struct {
unsigned char state[16]; /* state */
unsigned char checksum[16]; /* checksum */
unsigned int count; /* number of bytes, modulo 16 */
unsigned char buffer[16]; /* input buffer */
} MD2_CTX;
static MD2_CTX mdbucket; /* MD2 data structure */
extern char sigs[SIG_MAX_LEN];
char *btob64(register unsigned char *pcbitvec, register char *pcout, int numbit)
;
void MD2Init(MD2_CTX *context);
void MD2Update (MD2_CTX *context, unsigned char *input, unsigned int inputLen);
void MD2Final (unsigned char digest[16], MD2_CTX *context);
/* This function is main routine to be called for signature.
*
* char *sig_md2_get (char *filename);
*
* --- filename: file that needs signature.
*/
char *sig_md2_get (char *filename)
{
int fd_in, siglen;
char *ps_signature;
unsigned char buffer[BUFSIZE];
int readin = -1;
/* int i; */
MD2_CTX *mdbuf;
/* char s[128]; */
unsigned char digest[16];
if ((fd_in = open(filename, O_RDONLY)) < 0) {
/* skip it if we had an error */
printf("Trying to open %s for signature", filename);
printf("Trying to open %s for signature", filename);
return NULL;
}
ps_signature = (char *)&sigs;
siglen = SIG_MAX_LEN;
mdbuf = &mdbucket;
ps_signature[0] = '\0';
/* rewind the file descriptor */
if (lseek(fd_in, 0, SEEK_SET) < 0) {
perror("sig_md2_get: lseek()");
exit(1);
}
MD2Init (mdbuf);
while ((readin = read(fd_in, (char *)buffer, (off_t) BUFSIZE)) > 0) {
MD2Update(mdbuf, buffer, readin);
}
if (readin < 0) {
perror("sig_md2_get: read()");
perror("sig_md2_get: read()");
exit(1);
}
MD2Final (digest, mdbuf);
/* base 64 */
btob64(digest, ps_signature, 128);
(void) close(fd_in);
ps_signature = (char *)&sigs;
return ps_signature;
}
/*******************************************************************
** Following is implementation of **
** MD2 Message Digest Algorithm **
** MD2 -- RSA Data Security, Inc., MD2 message-digest algorithm **
** Revised by Wang,D.B.,Dec.17,1999. **
********************************************************************/
static void MD2Transform(unsigned char state[16],
unsigned char checksum[16], unsigned char block[16]);
static void MD2_memcpy(POINTER output, POINTER input, unsigned int len);
perror("sig_md2_get: read()");
exit(1);
}
MD2Final (digest, mdbuf);
/* base 64 */
btob64(digest, ps_signature, 128);
(void) close(fd_in);
ps_signature = (char *)&sigs;
return ps_signature;
}
/*******************************************************************
** Following is implementation of **
** MD2 Message Digest Algorithm **
** MD2 -- RSA Data Security, Inc., MD2 message-digest algorithm **
** Revised by Wang,D.B.,Dec.17,1999. **
********************************************************************/
static void MD2Transform(unsigned char state[16],
unsigned char checksum[16], unsigned char block[16]);
static void MD2_memcpy(POINTER output, POINTER input, unsigned int len);
static void MD2_memcpy(POINTER output, POINTER input, unsigned int len);
static void MD2_memset(POINTER output, int value, unsigned int len);
/* Permutation of 0..255 constructed from the digits of pi. It gives a
"random" nonlinear byte substitution operation.
*/
static unsigned char PI_SUBST[256] = {
41, 46, 67, 201, 162, 216, 124, 1, 61, 54, 84, 161, 236, 240, 6,
19, 98, 167, 5, 243, 192, 199, 115, 140, 152, 147, 43, 217, 188,
76, 130, 202, 30, 155, 87, 60, 253, 212, 224, 22, 103, 66, 111, 24,
138, 23, 229, 18, 190, 78, 196, 214, 218, 158, 222, 73, 160, 251,
245, 142, 187, 47, 238, 122, 169, 104, 121, 145, 21, 178, 7, 63,
148, 194, 16, 137, 11, 34, 95, 33, 128, 127, 93, 154, 90, 144, 50,
39, 53, 62, 204, 231, 191, 247, 151, 3, 255, 25, 48, 179, 72, 165,
181, 209, 215, 94, 146, 42, 172, 86, 170, 198, 79, 184, 56, 210,
150, 164, 125, 182, 118, 252, 107, 226, 156, 116, 4, 241, 69, 157,
112, 89, 100, 113, 135, 32, 134, 91, 207, 101, 230, 45, 168, 2, 27,
96, 37, 173, 174, 176, 185, 246, 28, 70, 97, 105, 52, 64, 126, 15,
85, 71, 163, 35, 221, 81, 175, 58, 195, 92, 249, 206, 186, 197,
234, 38, 44, 83, 13, 110, 133, 40, 132, 9, 211, 223, 205, 244, 65,
129, 77, 82, 106, 220, 55, 200, 108, 193, 171, 250, 36, 225, 123,
8, 12, 189, 177, 74, 120, 136, 149, 139, 227, 99, 232, 109, 233,
203, 213, 254, 59, 0, 29, 57, 242, 239, 183, 14, 102, 88, 208, 228,
203, 213, 254, 59, 0, 29, 57, 242, 239, 183, 14, 102, 88, 208, 228,
166, 119, 114, 248, 235, 117, 75, 10, 49, 68, 80, 180, 143, 237,
31, 26, 219, 153, 141, 51, 159, 17, 131, 20
};
static unsigned char *PADDING[] = {
(unsigned char *)"",
(unsigned char *)"\001",
(unsigned char *)"\002\002",
(unsigned char *)"\003\003\003",
(unsigned char *)"\004\004\004\004",
(unsigned char *)"\005\005\005\005\005",
(unsigned char *)"\006\006\006\006\006\006",
(unsigned char *)"\007\007\007\007\007\007\007",
(unsigned char *)"\010\010\010\010\010\010\010\010",
(unsigned char *)"\011\011\011\011\011\011\011\011\011",
(unsigned char *)"\012\012\012\012\012\012\012\012\012\012",
(unsigned char *)"\013\013\013\013\013\013\013\013\013\013\013",
(unsigned char *)"\014\014\014\014\014\014\014\014\014\014\014\014",
(unsigned char *)
"\015\015\015\015\015\015\015\015\015\015\015\015\015",
(unsigned char *)
"\016\016\016\016\016\016\016\016\016\016\016\016\016\016",
"\016\016\016\016\016\016\016\016\016\016\016\016\016\016",
(unsigned char *)
"\017\017\017\017\017\017\017\017\017\017\017\017\017\017\017",
(unsigned char *)
"\020\020\020\020\020\020\020\020\020\020\020\020\020\020\020\020"
};
/* MD2 initialization. Begins an MD2 operation, writing a new context.
*/
void MD2Init(MD2_CTX *context)
{
context->count = 0;
MD2_memset ((POINTER)context->state, 0, sizeof (context->state));
MD2_memset
((POINTER)context->checksum, 0, sizeof (context->checksum));
}
/* MD2 block update operation. Continues an MD2 message-digest
operation, processing another message block, and updating the
context.
*/
void MD2Update(MD2_CTX *context, unsigned char *input, unsigned int inputLen)
{
{
unsigned int i, index, partLen;
/* Update number of bytes mod 16 */
index = context->count;
context->count = (index + inputLen) & 0xf;
partLen = 16 - index;
/* Transform as many times as possible.
*/
if (inputLen >= partLen) {
MD2_memcpy
((POINTER)&context->buffer[index], (POINTER)input, partLen);
MD2Transform (context->state, context->checksum, context->buffer);
for (i = partLen; i + 15 < inputLen; i += 16)
MD2Transform (context->state, context->checksum, &input[i]);
index = 0;
}
else
i = 0;
i = 0;
/* Buffer remaining input */
MD2_memcpy
((POINTER)&context->buffer[index], (POINTER)&input[i],
inputLen-i);
}
/* MD2 finalization. Ends an MD2 message-digest operation, writing the
message digest and zeroizing the context.
*/
void MD2Final(unsigned char digest[16], MD2_CTX *context)
{
unsigned int index, padLen;
/* Pad out to multiple of 16.
*/
index = context->count;
padLen = 16 - index;
MD2Update (context, PADDING[padLen], padLen);
/* Extend with checksum */
MD2Update (context, context->checksum, 16);
MD2Update (context, context->checksum, 16);
/* Store state in digest */
MD2_memcpy ((POINTER)digest, (POINTER)context->state, 16);
/* Zeroize sensitive information.
*/
MD2_memset ((POINTER)context, 0, sizeof (*context));
}
/* MD2 basic transformation. Transforms state and updates checksum
based on block.
*/
static void MD2Transform(unsigned char state[16],
unsigned char checksum[16], unsigned char block[16])
{
unsigned int i, j, t;
unsigned char x[48];
/* Form encryption block from state, block, state ^ block.
*/
MD2_memcpy ((POINTER)x, (POINTER)state, 16);
MD2_memcpy ((POINTER)x+16, (POINTER)block, 16);
MD2_memcpy ((POINTER)x+16, (POINTER)block, 16);
for (i = 0; i < 16; i++)
x[i+32] = state[i] ^ block[i];
/* Encrypt block (18 rounds).
*/
t = 0;
for (i = 0; i < 18; i++) {
for (j = 0; j < 48; j++)
t = x[j] ^= PI_SUBST[t];
t = (t + i) & 0xff;
}
/* Save new state */
MD2_memcpy ((POINTER)state, (POINTER)x, 16);
/* Update checksum.
*/
t = checksum[15];
for (i = 0; i < 16; i++)
t = checksum[i] ^= PI_SUBST[block[i] ^ t];
/* Zeroize sensitive information.
/* Zeroize sensitive information.
*/
MD2_memset ((POINTER)x, 0, sizeof (x));
}
/* Note: Replace "for loop" with standard memcpy if possible.
*/
static void MD2_memcpy(POINTER output, POINTER input, unsigned int len)
{
unsigned int i;
for (i = 0; i < len; i++)
output[i] = input[i];
}
/* Note: Replace "for loop" with standard memset if possible.
*/
static void MD2_memset(POINTER output, int value, unsigned int len)
{
unsigned int i;
for (i = 0; i < len; i++)
((char *)output)[i] = (char)value;
for (i = 0; i < len; i++)
}
--
我问飘逝的风：来迟了？
风感慨：是的，他们已经宣战。
我问苏醒的大地：还有希望么？
大地揉了揉眼睛：还有，还有无数代的少年。
我问长空中的英魂：你们相信？
英魂带着笑意离去：相信，希望还在。
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