Class: Rex::Proto::NTLM::Crypt

Inherits:
Object
  • Object
show all
Defined in:
lib/rex/proto/ntlm/crypt.rb

Constant Summary collapse

CONST =
Rex::Proto::NTLM::Constants
BASE =
Rex::Proto::NTLM::Base
@@loaded_openssl =
false

Class Method Summary collapse

Class Method Details

.apply_des(plain, keys) ⇒ Object

Raises:

  • (RuntimeError)

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# File 'lib/rex/proto/ntlm/crypt.rb', line 83

def self.apply_des(plain, keys)
  raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl
  dec = OpenSSL::Cipher.new('DES')
  keys.map do |k|
    dec.encrypt
    dec.key = k
    dec.update(plain) + dec.final
  end
end

.decrypt_sessionkey(encrypted_session_key, user_session_key) ⇒ Object

Raises:

  • (RuntimeError)

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# File 'lib/rex/proto/ntlm/crypt.rb', line 381

def self.decrypt_sessionkey(encrypted_session_key, user_session_key)
  raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl
  cipher = OpenSSL::Cipher.new('rc4')
  cipher.decrypt
  cipher.key = user_session_key
  cipher.update(encrypted_session_key)
end

.des_56_to_64(ckey56s) ⇒ Object


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# File 'lib/rex/proto/ntlm/crypt.rb', line 69

def self.des_56_to_64(ckey56s)
  ckey64 = []
  ckey56 = ckey56s.unpack('C*')
  ckey64[0] = ckey56[0]
  ckey64[1] = ((ckey56[0] << 7) & 0xFF) | (ckey56[1] >> 1)
  ckey64[2] = ((ckey56[1] << 6) & 0xFF) | (ckey56[2] >> 2)
  ckey64[3] = ((ckey56[2] << 5) & 0xFF) | (ckey56[3] >> 3)
  ckey64[4] = ((ckey56[3] << 4) & 0xFF) | (ckey56[4] >> 4)
  ckey64[5] = ((ckey56[4] << 3) & 0xFF) | (ckey56[5] >> 5)
  ckey64[6] = ((ckey56[5] << 2) & 0xFF) | (ckey56[6] >> 6)
  ckey64[7] =  (ckey56[6] << 1) & 0xFF
  ckey64.pack('C*')
end

.encrypt_sessionkey(session_key, user_session_key) ⇒ Object

Raises:

  • (RuntimeError)

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# File 'lib/rex/proto/ntlm/crypt.rb', line 373

def self.encrypt_sessionkey(session_key, user_session_key)
  raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl
  cipher = OpenSSL::Cipher.new('rc4')
  cipher.encrypt
  cipher.key = user_session_key
  cipher.update(session_key)
end

.gen_keys(str) ⇒ Object


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# File 'lib/rex/proto/ntlm/crypt.rb', line 65

def self.gen_keys(str)
  str.scan(/.{7}/).map{ |key| des_56_to_64(key) }
end

.is_hash_from_empty_pwd?(arg) ⇒ Boolean

this function will check if the net lm response provided correspond to en empty password

Returns:

  • (Boolean)

Raises:

  • (ArgumentError)

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# File 'lib/rex/proto/ntlm/crypt.rb', line 234

def self.is_hash_from_empty_pwd?(arg)
  hash_type = arg[:type]
  raise ArgumentError,"arg[:type] is mandatory" if not hash_type
  raise ArgumentError,"arg[:type] must be lm or ntlm" if not hash_type  =~ /^((lm)|(ntlm))$/

  ntlm_ver = arg[:ntlm_ver]
  raise ArgumentError,"arg[:ntlm_ver] is mandatory" if not ntlm_ver

  hash = arg[:hash]
  raise ArgumentError,"arg[:hash] is mandatory" if not hash

  srv_chall = arg[:srv_challenge]
  raise ArgumentError,"arg[:srv_challenge] is mandatory" if not srv_chall
  raise ArgumentError,"Server challenge length must be exactly 8 bytes" if srv_chall.length != 8

  #calculate responses for empty pwd
  case ntlm_ver
  when CONST::NTLM_V1_RESPONSE
    if hash.length != 24
      raise ArgumentError,"hash length must be exactly 24 bytes "
    end
    case hash_type
    when 'lm'
      arglm = { 	:lm_hash => self.lm_hash(''),
          :challenge => srv_chall}
      calculatedhash = self.lm_response(arglm)
    when 'ntlm'
      argntlm = { 	:ntlm_hash =>  self.ntlm_hash(''),
          :challenge => srv_chall }
      calculatedhash = self.ntlm_response(argntlm)
    end
  when CONST::NTLM_V2_RESPONSE
    raise ArgumentError,"hash length must be exactly 16 bytes " if hash.length != 16
    cli_chall = arg[:cli_challenge]
    raise ArgumentError,"arg[:cli_challenge] is mandatory in this case" if not cli_chall
    user = arg[:user]
    raise ArgumentError,"arg[:user] is mandatory in this case" if not user
    domain = arg[:domain]
    raise ArgumentError,"arg[:domain] is mandatory in this case" if not domain

    case hash_type
    when 'lm'
      raise ArgumentError,"Client challenge length must be exactly 8 bytes " if cli_chall.length != 8
      arglm = {	:ntlmv2_hash =>  self.ntlmv2_hash(user,'', domain),
          :challenge => srv_chall }
      optlm = {	:client_challenge => cli_chall}
      calculatedhash = self.lmv2_response(arglm, optlm)[0,16]
    when 'ntlm'
      raise ArgumentError,"Client challenge length must be bigger then 8 bytes " if cli_chall.length <= 8
      argntlm = { 	:ntlmv2_hash =>  self.ntlmv2_hash(user, '', domain),
          :challenge => srv_chall }
      optntlm = { 	:nt_client_challenge => cli_chall}
      calculatedhash = self.ntlmv2_response(argntlm,optntlm)[0,16]
    end
  when CONST::NTLM_2_SESSION_RESPONSE
    raise ArgumentError,"hash length must be exactly 16 bytes " if hash.length != 24
    cli_chall = arg[:cli_challenge]
    raise ArgumentError,"arg[:cli_challenge] is mandatory in this case" if not cli_chall
    raise ArgumentError,"Client challenge length must be exactly 8 bytes " if cli_chall.length != 8
    case hash_type
    when 'lm'
      raise ArgumentError, "ntlm2_session is incompatible with lm"
    when 'ntlm'
      argntlm = { 	:ntlm_hash =>  self.ntlm_hash(''),
          :challenge => srv_chall }
      optntlm = {	:client_challenge => cli_chall}
    end
    calculatedhash = self.ntlm2_session(argntlm,optntlm).join[24,24]
  else
    raise ArgumentError,"ntlm_ver is of unknown type"
  end
  hash == calculatedhash
end

.lanman_des(password, challenge) ⇒ Object

Synonym of lm_response for old compatibility with lib/rex/proto/smb/crypt


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# File 'lib/rex/proto/ntlm/crypt.rb', line 140

def self.lanman_des(password, challenge)
  lm_response({
    :lm_hash => self.lm_hash(password),
    :challenge => challenge
  })
end

.lanman_session_key(pass, srvchall, opt = {}) ⇒ Object

Used when LanMan Key flag is set


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# File 'lib/rex/proto/ntlm/crypt.rb', line 358

def self.lanman_session_key(pass, srvchall, opt = {})
  if opt[:pass_is_hash]
    halfhash = pass[0,8]
  else
    halfhash = lm_hash(pass.upcase[0,7],true)
  end
  plain = self.lm_response({
    :lm_hash => halfhash[0,7],
    :challenge => srvchall
  }, true )
  key = halfhash  + ["bdbdbdbdbdbd"].pack("H*")
      keys = self.gen_keys(key)
     	apply_des(plain, keys).join
end

.lm_hash(password, half = false) ⇒ Object


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# File 'lib/rex/proto/ntlm/crypt.rb', line 93

def self.lm_hash(password, half = false)
  size = half ? 7 : 14
  keys = gen_keys(password.upcase.ljust(size, "\0"))
  apply_des(CONST::LM_MAGIC, keys).join
end

.lm_response(arg, half = false) ⇒ Object

Create the LANMAN response


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# File 'lib/rex/proto/ntlm/crypt.rb', line 126

def self.lm_response(arg, half = false)
  begin
    hash = arg[:lm_hash]
    chal = arg[:challenge]
  rescue
    raise ArgumentError
  end
  chal = BASE::pack_int64le(chal) if chal.is_a?(Integer)
  if half then size = 7 else  size = 21 end
  keys = gen_keys hash.ljust(size, "\0")
  apply_des(chal, keys).join
end

.lmv1_user_session_key(pass, opt = {}) ⇒ Object

Used when only the LMv1 response is provided (i.e., with Win9x clients)


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# File 'lib/rex/proto/ntlm/crypt.rb', line 315

def self.lmv1_user_session_key(pass, opt = {})
  if opt[:pass_is_hash]
    usk = pass[0,8]
  else
    usk = self.lm_hash(pass.upcase[0,7],true)
  end
  usk.ljust(16,"\x00")
end

.lmv2_response(arg, opt = {}) ⇒ Object

Raises:

  • (RuntimeError)

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# File 'lib/rex/proto/ntlm/crypt.rb', line 205

def self.lmv2_response(arg, opt = {})
  raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl
  key = arg[:ntlmv2_hash]
  chal = arg[:challenge]

  chal = BASE::pack_int64le(chal) if chal.is_a?(::Integer)
  cc   = opt[:client_challenge] || rand(CONST::MAX64)
  cc   = BASE::pack_int64le(cc) if cc.is_a?(::Integer)

  OpenSSL::HMAC.digest(OpenSSL::Digest.new('MD5'), key, chal + cc) + cc
end

.lmv2_user_session_key(user, pass, domain, srv_chall, cli_chall, opt = {}) ⇒ Object Also known as: ntlmv2_user_session_key

Used when the LMv2 response is sent

Raises:

  • (RuntimeError)

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# File 'lib/rex/proto/ntlm/crypt.rb', line 346

def self.lmv2_user_session_key(user, pass, domain, srv_chall, cli_chall, opt = {})
  raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl

  ntlmv2_key = self.ntlmv2_hash(user, pass, domain, opt)
  hash1 = OpenSSL::HMAC.digest(OpenSSL::Digest.new('MD5'), ntlmv2_key, srv_chall + cli_chall)
  OpenSSL::HMAC.digest(OpenSSL::Digest.new('MD5'), ntlmv2_key, hash1)
end

.make_weak_sessionkey(session_key, key_size, lanman_key = false) ⇒ Object


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# File 'lib/rex/proto/ntlm/crypt.rb', line 389

def self.make_weak_sessionkey(session_key,key_size,lanman_key = false)
  case key_size
  when 40
    if lanman_key
      return session_key[0,5] + "\xe5\x38\xb0"
    else
      return session_key[0,5]
    end
  when 56
    if lanman_key
      return session_key[0,7]  + "\xa0"
    else
      return session_key[0,7]
    end
  else #128
    return session_key[0,16]
  end
end

.ntlm2_session(arg, opt = {}) ⇒ Object

Raises:

  • (RuntimeError)

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# File 'lib/rex/proto/ntlm/crypt.rb', line 217

def self.ntlm2_session(arg, opt = {})
  raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl
  passwd_hash,chal = arg[:ntlm_hash],arg[:challenge]
  if not (passwd_hash and chal)
    raise RuntimeError, "ntlm_hash and challenge are required"
  end

  cc = opt[:client_challenge] || rand(CONST::MAX64)
  cc = BASE::pack_int64le(cc) if cc.is_a?(Integer)

  keys = gen_keys(passwd_hash.ljust(21, "\0"))
  session_hash = OpenSSL::Digest::MD5.digest(chal + cc)[0,8]
  response = apply_des(session_hash, keys).join
  [cc.ljust(24, "\0"), response]
end

.ntlm2_session_user_session_key(pass, srv_chall, cli_chall, opt = {}) ⇒ Object

Used when NTLMv1 authentication is employed with NTLM2 session security

Raises:

  • (RuntimeError)

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# File 'lib/rex/proto/ntlm/crypt.rb', line 337

def self.ntlm2_session_user_session_key(pass, srv_chall, cli_chall, opt = {})
  raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl

  ntlm_key = self.ntlmv1_user_session_key(pass, opt )
  session_chal = srv_chall + cli_chall
  OpenSSL::HMAC.digest(OpenSSL::Digest.new('MD5'), ntlm_key, session_chal)
end

.ntlm_hash(password, opt = {}) ⇒ Object

Raises:

  • (RuntimeError)

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# File 'lib/rex/proto/ntlm/crypt.rb', line 99

def self.ntlm_hash(password, opt = {})
  raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl
  pwd = password.dup
  unless opt[:unicode]
    pwd = Rex::Text.to_unicode(pwd)
  end
  OpenSSL::Digest::MD4.digest(pwd)
end

.ntlm_md4(password, challenge) ⇒ Object

synonym of ntlm_response for old compatibility with lib/rex/proto/smb/crypt


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# File 'lib/rex/proto/ntlm/crypt.rb', line 156

def self.ntlm_md4(password, challenge)
  ntlm_response({
    :ntlm_hash =>  self.ntlm_hash(password),
    :challenge => challenge
  })
end

.ntlm_response(arg) ⇒ Object


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# File 'lib/rex/proto/ntlm/crypt.rb', line 147

def self.ntlm_response(arg)
  hash = arg[:ntlm_hash]
  chal = arg[:challenge]
  chal = BASE::pack_int64le(chal) if chal.is_a?(::Integer)
  keys = gen_keys(hash.ljust(21, "\0"))
  apply_des(chal, keys).join
end

.ntlmv1_user_session_key(pass, opt = {}) ⇒ Object

This variant is used when the client sends the NTLMv1 response

Raises:

  • (RuntimeError)

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# File 'lib/rex/proto/ntlm/crypt.rb', line 325

def self.ntlmv1_user_session_key(pass, opt = {})
  raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl

  if opt[:pass_is_hash]
    usk = pass
  else
    usk = self.ntlm_hash(pass)
  end
  OpenSSL::Digest::MD4.digest(usk)
end

.ntlmv2_hash(user, password, domain, opt = {}) ⇒ Object

This hash is used for lmv2/ntlmv2 response calculation

Raises:

  • (RuntimeError)

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# File 'lib/rex/proto/ntlm/crypt.rb', line 109

def self.ntlmv2_hash(user, password, domain, opt={})
  raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl

  if opt[:pass_is_hash]
    ntlmhash = password
  else
    ntlmhash = ntlm_hash(password, opt)
  end
  # With Win 7 and maybe other OSs we sometimes get the domain not uppercased
  userdomain = user.upcase  + domain
  unless opt[:unicode]
    userdomain = Rex::Text.to_unicode(userdomain)
  end
  OpenSSL::HMAC.digest(OpenSSL::Digest.new('MD5'), ntlmhash, userdomain)
end

.ntlmv2_response(arg, opt = {}) ⇒ Object

Raises:

  • (RuntimeError)

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# File 'lib/rex/proto/ntlm/crypt.rb', line 163

def self.ntlmv2_response(arg, opt = {})
  raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl

  key, chal = arg[:ntlmv2_hash], arg[:challenge]
  if not (key and chal)
    raise ArgumentError , 'ntlmv2_hash and challenge are mandatory'
  end

  chal = BASE::pack_int64le(chal) if chal.is_a?(::Integer)
  bb   = nil

  if opt[:nt_client_challenge]
    if opt[:nt_client_challenge].to_s.length <= 8
      raise ArgumentError,"nt_client_challenge is not in a correct format "
    end
    bb = opt[:nt_client_challenge]
  else
    if not arg[:target_info]
      raise ArgumentError, "target_info is mandatory in this case"
    end

    ti = arg[:target_info]
    cc = opt[:client_challenge] || rand(CONST::MAX64)
    cc = BASE::pack_int64le(cc) if cc.is_a?(::Integer)

    ts = opt[:timestamp] || ::Time.now.to_i

    # Convert the unix timestamp to windows format
    #   epoch -> milsec from Jan 1, 1601
    ts = 10000000 * (ts + CONST::TIME_OFFSET)

    blob = BASE::Blob.new
    blob.timestamp = ts
    blob.challenge = cc
    blob.target_info = ti

    bb = blob.serialize
  end

  OpenSSL::HMAC.digest(OpenSSL::Digest.new('MD5'), key, chal + bb) + bb
end