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LM hash, LanMan hash, or LAN Manager hash is a compromised password hashing function that was the primary hash that Microsoft LAN Manager and Microsoft Windows versions prior to Windows NT used to store user passwords. Support for the legacy LAN Manager protocol continued in later versions of Windows for backward compatibility, but was recommended by Microsoft to be turned off by administrators; as of Windows Vista, the protocol is disabled by default, but continues to be used by some non-Microsoft CIFS implementations. == Algorithm == The LM hash is computed as follows:〔(【引用サイトリンク】 title=Chapter 3 - Operating System Installation: The LMHash )〕 # The user's password is restricted to a maximum of fourteen characters.〔If the password is more than fourteen characters long, the LM hash cannot be computed.〕 # The user’s password is converted to uppercase. # The user's password is encoded in the System OEM Code page〔(【引用サイトリンク】 title=List of Localized MS Operating Systems )〕 # This password is null-padded to 14 bytes. # The “fixed-length” password is split into two 7-byte halves. # These values are used to create two DES keys, one from each 7-byte half, by converting the seven bytes into a bit stream with the most significant bit first, and inserting a null bit after every seven bits (so 1010100 becomes 10101000). This generates the 64 bits needed for a DES key. (A DES key ostensibly consists of 64 bits; however, only 56 of these are actually used by the algorithm. The null bits added in this step are later discarded.)# Each of the two keys is used to DES-encrypt the constant ASCII string “ KGS!@#$%”,〔The string “KGS!@#$%” could possibly mean Key of Glen and Steve and then the combination of Shift + 12345. Glen Zorn and Steve Cobb are the authors of RFC 2433 (Microsoft PPP CHAP Extensions).〕 resulting in two 8-byte ciphertext values. The DES CipherMode should be set to ECB, and PaddingMode should be set to NONE.# These two ciphertext values are concatenated to form a 16-byte value, which is the LM hash. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「LM hash」の詳細全文を読む スポンサード リンク
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