1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
|
/*
* Functions to implement type MD5 cancel locks. Written by Fluffy, Ruler
* of All Usenet, and placed into the public domain. Meow.
*/
#include <stdio.h>
#include <sys/types.h>
#include "base64.h"
#include "md5.h"
#include "hmac_md5.h"
#include "canlock.h"
#define BUFFSIZE 40
/*
* Generate an MD5 cancel key.
*/
unsigned char *
md5_key(char *secret, int seclen, char *message, int msglen)
{
unsigned char *cankey;
unsigned char *canlock;
unsigned char *hmacbuff;
MD5_CTX hash_ctx;
cankey = (char *) malloc(BUFFSIZE);
hmacbuff = hmac_md5(secret, seclen, message, msglen);
strcpy(cankey, "md5:");
(void) b64_ntop(hmacbuff, MD5_LENGTH, cankey + 4, BUFFSIZE);
return (cankey);
}
/*
* Generate an MD5 cancel lock.
*/
unsigned char *
md5_lock(char *secret, int seclen, char *message, int msglen)
{
unsigned char *cankey, *canlock;
unsigned char hmacbuff[MD5_LENGTH];
unsigned char junk[MD5_LENGTH];
MD5_CTX hash_ctx;
cankey = lock_strip_alpha(md5_key(secret, seclen, message, msglen), junk);
canlock = (char *) malloc(BUFFSIZE);
MD5Init(&hash_ctx);
MD5Update(&hash_ctx, cankey, strlen(cankey));
MD5Final(hmacbuff, &hash_ctx);
strcpy(canlock, "md5:");
(void) b64_ntop(hmacbuff, MD5_LENGTH, canlock + 4, BUFFSIZE);
return (canlock);
}
/*
* Verify an SHA cancel key against a cancel lock.
* Returns 0 on success, nonzero on failure.
*/
int md5_verify(unsigned char *key, unsigned char *lock)
{
unsigned char binkey[MD5_LENGTH + 4];
unsigned char templock[BUFFSIZE];
unsigned char hmacbuff[MD5_LENGTH];
MD5_CTX hash_ctx;
int verified;
/* Convert the key back into binary */
(void) b64_pton(key, binkey, (MD5_LENGTH + 4));
MD5Init(&hash_ctx);
MD5Update(&hash_ctx, key, strlen(key));
MD5Final(hmacbuff, &hash_ctx);
(void) b64_ntop(hmacbuff, MD5_LENGTH, templock, BUFFSIZE);
verified = strcmp(templock, lock);
return (verified);
}
|
