NTLM hashes are generated with the use of a NTLM algorithm. The NTLM algorithm is an extension of the LM algorithm, which was originally developed in 1973 by Stanford University students, Don Coppersmith and Ralph Merkle.
Nt Hash Generator
The NTLM protocol uses one or both of two hashed password values, both of which are also stored on the server (or domain controller), and which through a lack of salting are password equivalent, meaning that if you grab the hash value from the server, you can authenticate without knowing the actual password. The two are the LM hash (a DES-based function applied to the first 14 characters of the password converted to the traditional 8-bit PC charset for the language), and the NT hash (MD4 of the little endian UTF-16 Unicode password). Both hash values are 16 bytes (128 bits) each.[12]
The server authenticates the client by sending an 8-byte random number, the challenge. The client performs an operation involving the challenge and a secret shared between client and server, specifically one of the two password hashes described above. The client returns the 24-byte result of the computation. In fact, in NTLMv1 the computations are usually made using both hashes and both 24-byte results are sent. The server verifies that the client has computed the correct result, and from this infers possession of the secret, and hence the authenticity of the client.
Both the hashes produce 16-byte quantities. Five bytes of zeros are appended to obtain 21 bytes. The 21 bytes are separated in three 7-byte (56-bit) quantities. Each of these 56-bit quantities is used as a key to DES encrypt the 64-bit challenge. The three encryptions of the challenge are reunited to form the 24-byte response. Both the response using the LM hash and the NT hash are returned as the response, but this is configurable.
NTLMv2 sends two responses to an 8-byte server challenge. Each response contains a 16-byte HMAC-MD5 hash of the server challenge, a fully/partially randomly generated client challenge, and an HMAC-MD5 hash of the user's password and other identifying information. The two responses differ in the format of the client challenge. The shorter response uses an 8-byte random value for this challenge. In order to verify the response, the server must receive as part of the response the client challenge. For this shorter response, the 8-byte client challenge appended to the 16-byte response makes a 24-byte package which is consistent with the 24-byte response format of the previous NTLMv1 protocol. In certain non-official documentation (e.g. DCE/RPC Over SMB, Leighton) this response is termed LMv2.
Both LMv2 and NTv2 hash the client and server challenge with the NT hash of the user's password and other identifying information. The exact formula is to begin with the NT hash, which is stored in the SAM or AD, and continue to hash in, using HMAC-MD5, the username and domain name. In the box below, X stands for the fixed contents of a formatting field.
Briefly, the NTLMv1 algorithm is applied, except that an 8-byte client challenge is appended to the 8-byte server challenge and MD5-hashed. The least 8-byte half of the hash result is the challenge utilized in the NTLMv1 protocol. The client challenge is returned in one 24-byte slot of the response message, the 24-byte calculated response is returned in the other slot.
However, existing NTLMv1 infrastructure allows that the challenge/response pair is not verified by the server, but sent to a Domain Controller for verification. Using NTLM2 Session, this infrastructure continues to work if the server substitutes for the challenge the hash of the server and client challenges.
Microsoft has added the NTLM hash to its implementation of the Kerberos protocol to improve interoperability (in particular, the RC4-HMAC encryption type). According to an independent researcher, this design decision allows Domain Controllers to be tricked into issuing an attacker with a Kerberos ticket if the NTLM hash is known.[20]Microsoft adopted Kerberos as the preferred authentication protocol for Windows 2000 and subsequent Active Directory domains.[16] Kerberos is typically used when a server belongs to a Windows Server domain. Microsoft recommends developers neither to use Kerberos nor the NTLM Security Support Provider (SSP) directly.[21]
In Windows Vista and above, LM has been disabled for inbound authentication. Windows NT-based operating systems up through and including Windows Server 2003 store two password hashes, the LAN Manager (LM) hash and the Windows NT hash. Starting in Windows Vista, the capability to store both is there, but one is turned off by default. This means that LM authentication no longer works if the computer running Windows Vista acts as the server. Prior versions of Windows (back as far as Windows NT 4.0 Service Pack 4) could be configured to behave this way, but it was not the default.[25]
NTLM remains vulnerable to the pass the hash attack, which is a variant on the reflection attack which was addressed by Microsoft security update MS08-068. For example, Metasploit can be used in many cases to obtain credentials from one machine which can be used to gain control of another machine.[3][26] The Squirtle toolkit can be used to leverage web site cross-site scripting attacks into attacks on nearby assets via NTLM.[27]
Note that the password-equivalent hashes used in pass-the-hash attacks and password cracking must first be "stolen" (such as by compromising a system with permissions sufficient to access hashes). Also, these hashes are not the same as the NTLMSSP_AUTH "hash" transmitted over the network during a conventional NTLM authentication.
I was wondering if there is a standard Linux/Ubuntu command to generate SMB password hashes to stdout. For the curious, I am wanting to manage a set of usernames and passwords across multiple machines (using Puppet) including access via Samba (for now, not using something more general like LDAP). More specifically, an equivalent of this command that I use to generate Linux password entries but for SMB/Samba:
The project is NTLM hash generator in pure C/C++ (without using windows APIs or libraries). It's useful for developers whom want to work with windows authentication related projects, rainbow table etc.
The NTLM() function has one char array parameter. It's the string that NTLM hash of that should be calculated. If you want to use NTLM() function in your code, just copy/paste it (don't forget to copy my global definitions too).Before starting of hash calculation, there is a piece of code:
The code maps the string to sixteen unsigned ints. That's the way hash calculation starts to process. unsigned ints are input of hash calculation.Calculation of NTLM has 3 phrases that I marked them in comments like this:
If you are interested of NTLM hash calculation's phrases deeply, you should read about how MD4 hash works. Because NTLM is MD4 of the little endian UTF-16 Unicode. After "Round 3", hash is ready. The last part of NTLM() function, converts calculated hash to hex. Because hex is more readable to human.
Hashing is a one-way cryptographic function, and although hashing is often confused with encryption, they are in fact very different. Encryption is generally reversible, that is, as long as the encryption key is known the data can be decrypted. Hashing cannot be reversed. To determine the cleartext that produced a hash we have to first hash something, in this case passwords, and then compare that hash to the known hash. If they match, we know we have the correct password, otherwise we know our password guess is incorrect.
Single mode is useful when you want to quickly obtain the NTLM hash of a specific string (password), maybe for use in a Pass-the-Hash (PtH) attack, simply to validate the hash of a password, to test the efficacy or likelihood of hash cracking techniques, or maybe even to search an NTDS.dit database for a known cleartext password.
First, I seeded a wordlist by adding these 6 strings to the rockyou.txt wordlist. Then using my favorite password-cracking utility, Hashcat, I ran a dictionary attack with the InsidePro-PasswordsPro ruleset. Expectedly, Hashcat cracked all six hashes and the cleartext strings matched our test strings, which means NTLMme.py is producing the correct NTLM hashes.
Finally, in yet another upcoming blog post I will elaborate on the NTLM hash cracking analysis that influenced the creation of this NTLM hash generator script. In the meantime, contact us if you would like us to handle your pentesting. We have an expert team that is ready to help!
For use in Windows networking, including Active Directory domains, the password is stored two different ways by default: as the LAN Manager one-way function (LM OWF) and as the NT OWF. "One-way function" is a term that denotes a one-way mathematical transformation of data. The data that is being transformed can only be converted through encryption one way and cannot be reversed. The most common type of one-way function in use is a cryptographic hash. A hash is a small set of data that is mathematically tied to some larger set of data from which the hash is calculated. If the larger set of data is changed, the hash also changes. Hashes are useful, for example, as a checksum to verify that data has not been modified in transmission. A cryptographic hash is a hash that fulfills certain properties. A cryptographic hash must, for instance, be created in such a way that it is mathematically infeasible in a reasonable amount of time to infer the larger set of data from only the hash. Likewise, it is mathematically infeasible to find two sets of large data that generate the same hash.
There are many different types of one-way functions. All hash functions are, by definition, one-way functions. However, ordinary cryptographic functions that are typically reversible can also be used to create a one-way function. This can be done by swapping the data and the key in a cryptographic function and encrypting the fixed value (the key) by using the data as the key. This is how the LM hash is computed. The LM hash is computed as follows: 2ff7e9595c
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