Package uk.co.westhawk.snmp.util

Class SnmpUtilities

java.lang.Object
uk.co.westhawk.snmp.util.SnmpUtilities
public class SnmpUtilities extends Object
This class contains utilities for key and authentication encoding. See SNMP-USER-BASED-SM-MIB.
Version:
$Revision: 1.27 $ $Date: 2009/03/05 12:57:57 $
Author:
Tim Panton

  • Constructor Summary

    Constructors
    Constructor
    Description
    SnmpUtilities()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    static final byte[]
    AESdecrypt(byte[] ciphertext, byte[] secretPrivacyKey, int engineBoots, int engineTime, byte[] salt)
    Decrypts using AES.
    static byte[]
    AESencrypt(byte[] plaintext, byte[] secretPrivacyKey, int engineBoots, int engineTime, byte[] salt)
    Encrypts bytes using AES.
    static boolean
    areBytesEqual(byte[] array1, byte[] array2)
    Compaires two byte arrays and returns if they are equal.
    static void
    copyFingerprintToSnmpMessage(int authenticationProtocol, byte[] computedFingerprint, byte[] message, int fpPos)
    Copies the calculated fingerprint to the message at the specified position.
    static final byte[]
    DESdecrypt(byte[] encryptedText, byte[] salt, byte[] secretPrivacyKey)
    Decryptes bytes using DES.
    static final byte[]
    DESencrypt(byte[] plain, byte[] secretPrivacyKey, byte[] salt)
    Encrypts bytes using DES.
    static void
    dumpBytes(String headerStr, byte[] bytes)
    Dumps (prints) the byte array.
    static byte[]
    getAESInitialValue(int engineBoots, int engineTime, byte[] salt)
    Returns the first 128 bits of the localized key Kul are used as the AES encryption key.
    static final byte[]
    getAESKey(byte[] secretPrivacyKey)
    Returns the first 128 bits of the localized key Kul are used as the AES encryption key.
    static final byte[]
    getDESInitialValue(byte[] secretPrivacyKey, byte[] salt)
    Returns the DES initial value.
    static final byte[]
    getDESKey(byte[] secretPrivacyKey)
    Returns the DES key.
    static final byte[]
    getFingerPrintMD5(byte[] key, byte[] message)
    Returns the 12 byte MD5 fingerprint.
    static final byte[]
    getFingerPrintSHA1(byte[] key, byte[] message)
    Returns the 12 byte SHA1 fingerprint.
    static byte[]
    getFingerPrintSHA224(byte[] key, byte[] message)
    Create a fingerprint using the SHA-224 algorithm with length 28 bytes for SNMPv3.
    static byte[]
    getFingerPrintSHA256(byte[] key, byte[] message)
    Create a fingerprint using the SHA-256 algorithm with length 24 bytes.
    static byte[]
    getFingerPrintSHA384(byte[] key, byte[] message)
    Create a fingerprint using the SHA-384 algorithm with length 36 bytes.
    static byte[]
    getFingerPrintSHA512(byte[] key, byte[] message)
    Create a fingerprint using the SHA-512 algorithm with length 48 bytes.
    static byte[]
    getLocalizedKeyMD5(byte[] passwKey, String engineId)
    Converts the user's password and the SNMP Engine Id to the localized key using the MD5 protocol.
    static byte[]
    getLocalizedKeySHA1(byte[] passwKey, String engineId)
    Converts the user's password and the SNMP Engine Id to the localized key using the SHA protocol.
    static byte[]
    getLocalizedKeySHA224(byte[] passwKey, String snmpEngineId)
    Converts the user's password and the SNMP Engine Id to the localized key
    static byte[]
    getLocalizedKeySHA256(byte[] passwKey, String snmpEngineId)
    Converts the user's password and the SNMP Engine Id to the localized key
    static byte[]
    getLocalizedKeySHA384(byte[] passwKey, String snmpEngineId)
    Converts the user's password and the SNMP Engine Id to the localized key
    static byte[]
    getLocalizedKeySHA512(byte[] passwKey, String snmpEngineId)
    Converts the user's password and the SNMP Engine Id to the localized key using the SHA-512 protocol.
    static byte[]
    getSaltAES()
    Returns the AES salt.
    static final byte[]
    getSaltDES(int snmpEngineBoots)
    Returns the DES salt.
    static String
    getSnmpVersionString(int version)
    Returns the String representation of the SNMP version number.
    static byte[]
    initFingerprint(int authenticationProtocol)
    Returns an `AsnOctets` object with a dummy fingerprint based on the authentication protocol.
    static byte
    longToByte(long l)
    Converts one long value to its byte value.
    static byte[]
    longToByte(long[] l)
    Converts an array of long values to its array of byte values.
    static byte[]
    passwordToKeyMD5(String password)
    Converts the user's password to an authentication key using the MD5 protocol.
    static byte[]
    passwordToKeySHA1(String password)
    Converts the user's password to an authentication key using the SHA1 protocol.
    static byte[]
    passwordToKeySHA224(String userPrivacyPassword)
    Converts the user's passphrase into a 28-byte SHA-224 key by hashing one megabyte of repeated passphrase data.
    static byte[]
    passwordToKeySHA256(String userPrivacyPassword)
    Converts the user's passphrase into a 32-byte SHA-256 key by hashing one megabyte of repeated passphrase data.
    static byte[]
    passwordToKeySHA384(String userPrivacyPassword)
    Converts the user's passphrase into a 48-byte SHA-384 key by hashing one megabyte of repeated passphrase data.
    static byte[]
    passwordToKeySHA512(String userPrivacyPassword)
    Converts the user's passphrase into a 64-byte SHA-512 key by hashing one megabyte of repeated passphrase data.
    static byte[]
    toBytes(String hexStr)
    Converts a hexadecimal ASCII string to a byte array.
    static String
    toHex(int val)
    Converts one int to a hexadecimal ASCII string.
    static String
    toHexString(byte[] bytes)
    Converts a byte array to a hexadecimal ASCII string.

    Methods inherited from class java.lang.Object

    equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • SnmpUtilities

      public SnmpUtilities()

  • Method Details

    • getSnmpVersionString

      public static String getSnmpVersionString(int version)
      Returns the String representation of the SNMP version number.
      Parameters:
      version - The version number
      Returns:
      The corresponding String.

    • toBytes

      public static byte[] toBytes(String hexStr)
      Converts a hexadecimal ASCII string to a byte array. The method is case insensitive, so F7 works as well as f7. The string should have the form F7d820 and should omit the '0x'. This method is the reverse of toHexString.
      Parameters:
      hexStr - The string representing a hexadecimal number
      Returns:
      the byte array of hexStr
      See Also:

    • longToByte

      public static byte longToByte(long l) throws IllegalArgumentException
      Converts one long value to its byte value.
      Parameters:
      l - The long value
      Returns:
      It's byte value
      Throws:
      IllegalArgumentException - when l is not in between 0 and 255.
      Since:
      4_14
      See Also:

    • longToByte

      public static byte[] longToByte(long[] l) throws IllegalArgumentException
      Converts an array of long values to its array of byte values.
      Parameters:
      l - The array of longs
      Returns:
      The array of bytes
      Throws:
      IllegalArgumentException - when one of the longs is not in between 0 and 255.
      Since:
      4_14
      See Also:

    • dumpBytes

      public static void dumpBytes(String headerStr, byte[] bytes)
      Dumps (prints) the byte array. Debug method.
      Parameters:
      headerStr - String that will be printed as header
      bytes - Bytes to be dumped as hex.

    • toHexString

      public static String toHexString(byte[] bytes)
      Converts a byte array to a hexadecimal ASCII string. The string will be in upper case and does not start with '0x'. This method is the reverse of toBytes.
      Parameters:
      bytes - The byte array
      Returns:
      The string representing the byte array
      See Also:

    • toHex

      public static String toHex(int val)
      Converts one int to a hexadecimal ASCII string.
      Parameters:
      val - The integer
      Returns:
      The hex string

    • areBytesEqual

      public static boolean areBytesEqual(byte[] array1, byte[] array2)
      Compaires two byte arrays and returns if they are equal.
      Parameters:
      array1 - the first byte array
      array2 - the second byte array
      Returns:
      whether they are equal of not.

    • getLocalizedKeyMD5

      public static byte[] getLocalizedKeyMD5(byte[] passwKey, String engineId)
      Converts the user's password and the SNMP Engine Id to the localized key using the MD5 protocol. Described in SNMP-USER-BASED-SM-MIB.
      Parameters:
      passwKey - The password key
      engineId - The SNMP engine Id
      See Also:

    • getLocalizedKeySHA1

      public static byte[] getLocalizedKeySHA1(byte[] passwKey, String engineId)
      Converts the user's password and the SNMP Engine Id to the localized key using the SHA protocol.
      Parameters:
      passwKey - The printable user password
      engineId - The SNMP engine Id
      See Also:

    • passwordToKeySHA1

      public static byte[] passwordToKeySHA1(String password)
      Converts the user's password to an authentication key using the SHA1 protocol. Note, this is not the same as generating the localized key as is described in SNMP-USER-BASED-SM-MIB.
      Parameters:
      password - The printable user password
      See Also:

    • passwordToKeyMD5

      public static byte[] passwordToKeyMD5(String password)
      Converts the user's password to an authentication key using the MD5 protocol. Note, this is not the same as generating the localized key as is described in SNMP-USER-BASED-SM-MIB.
      Parameters:
      password - The printable user password
      See Also:

    • getFingerPrintMD5

      public static final byte[] getFingerPrintMD5(byte[] key, byte[] message)
      Returns the 12 byte MD5 fingerprint.
      Parameters:
      key - The key
      message - The message
      See Also:

    • getFingerPrintSHA1

      public static final byte[] getFingerPrintSHA1(byte[] key, byte[] message)
      Returns the 12 byte SHA1 fingerprint.
      Parameters:
      key - The key
      message - The message
      See Also:

    • getSaltDES

      public static final byte[] getSaltDES(int snmpEngineBoots)
      Returns the DES salt. The "salt" value is generated by concatenating the 32-bit snmpEngineBoots value with a 32-bit counter value that the encryption engine maintains. This 32-bit counter will be initialised to some arbitrary value at boot time.

      See "A Practical Guide to SNMPv3 and Network Management" section 6.8 Privacy, p 194.

      Parameters:
      snmpEngineBoots - The (estimated) boots of the authoritative engine
      Returns:
      The salt

    • getSaltAES

      public static byte[] getSaltAES()
      Returns the AES salt.
      Returns:
      The salt

    • getDESKey

      public static final byte[] getDESKey(byte[] secretPrivacyKey) throws PduException
      Returns the DES key. The 16-byte secret privacy key is made up of 8 bytes that make up the DES key and 8 bytes used as a preinitialisation vector.
      Parameters:
      secretPrivacyKey - The secret privacy key
      Returns:
      The key
      Throws:
      PduException

    • getAESKey

      public static final byte[] getAESKey(byte[] secretPrivacyKey) throws PduException
      Returns the first 128 bits of the localized key Kul are used as the AES encryption key.
      Parameters:
      secretPrivacyKey - The secret privacy key
      Returns:
      The key
      Throws:
      PduException

    • getDESInitialValue

      public static final byte[] getDESInitialValue(byte[] secretPrivacyKey, byte[] salt) throws PduException
      Returns the DES initial value. The 16-byte secret privacy key is made up of 8 bytes that make up the DES key and 8 bytes used as a preinitialisation vector. The initialization vector that is used by the DES algorithm is the result of the 8-byte preinitialisation vector XOR-ed with the 8-byte "salt".
      Parameters:
      secretPrivacyKey - The secret privacy key
      salt - The salt
      Returns:
      The initial value
      Throws:
      PduException

    • getAESInitialValue

      public static byte[] getAESInitialValue(int engineBoots, int engineTime, byte[] salt)
      Returns the first 128 bits of the localized key Kul are used as the AES encryption key. RFC 3826 3.1.2.1 AES Encryption Key and IV. The 128-bit IV is obtained as the concatenation of the authoritative SNMP engine's 32-bit snmpEngineBoots, the SNMP engine's 32-bit snmpEngineTime, and a local 64-bit integer. The 64-bit integer is initialized to a pseudo-random value at boot time.

    • AESencrypt

      public static byte[] AESencrypt(byte[] plaintext, byte[] secretPrivacyKey, int engineBoots, int engineTime, byte[] salt) throws EncodingException
      Encrypts bytes using AES.
      Parameters:
      plaintext - The plain bytes
      secretPrivacyKey - The secret privacy key
      engineBoots -
      engineTime -
      salt - The salt
      Returns:
      The encrypted bytes
      Throws:
      EncodingException

    • DESencrypt

      public static final byte[] DESencrypt(byte[] plain, byte[] secretPrivacyKey, byte[] salt) throws EncodingException
      Encrypts bytes using DES. The plaintext needs to be a multiple of 8 octets. If it isn't, it will be padded at the end. This plaintext will be divided into 64-bit blocks. The plaintext for each block is XOR-ed with the "ciphertext" of the previous block. The result is then encrypted, added to the encrypted PDU portion of the message, and used as the "ciphertext" for the next block. For the first block, the initialization vector is used as the "ciphertext".
      Parameters:
      plain - The plain bytes
      secretPrivacyKey - The secret privacy key
      salt - The salt
      Returns:
      The encrypted bytes
      Throws:
      EncodingException

    • DESdecrypt

      public static final byte[] DESdecrypt(byte[] encryptedText, byte[] salt, byte[] secretPrivacyKey) throws DecodingException
      Decryptes bytes using DES.
      • If the length of the data portion is not a multiple of 8 bytes, the message is discarded.
      • The first encrypted text block is decrypted. The decryption result is XOR-ed with the initialization vector, and the result is the first plaintext block.
      • The rest of the encrypted text blocks are treated similarly. They are decrypted, with the results being XOR-ed with the previous encrypted text block to obtain the plaintext block.
      Parameters:
      encryptedText - The encrypted text
      salt - The salt
      secretPrivacyKey - The secret privacy key
      Returns:
      The decrypted bytes
      Throws:
      DecodingException

    • AESdecrypt

      public static final byte[] AESdecrypt(byte[] ciphertext, byte[] secretPrivacyKey, int engineBoots, int engineTime, byte[] salt) throws DecodingException
      Decrypts using AES. Note that it uses the _forward_ cipher mode.
      Parameters:
      ciphertext -
      secretPrivacyKey - The secret privacy key
      engineBoots -
      engineTime -
      salt - The salt
      Returns:
      The dencrypted bytes
      Throws:
      DecodingException

    • passwordToKeySHA256

      public static byte[] passwordToKeySHA256(String userPrivacyPassword)
      Converts the user's passphrase into a 32-byte SHA-256 key by hashing one megabyte of repeated passphrase data. (Based on the MD5/SHA1 approach in RFC 3414, extended for SHA-256.)
      Parameters:
      userPrivacyPassword - The user's passphrase

    • passwordToKeySHA384

      public static byte[] passwordToKeySHA384(String userPrivacyPassword)
      Converts the user's passphrase into a 48-byte SHA-384 key by hashing one megabyte of repeated passphrase data. (Based on the MD5/SHA1 approach in RFC 3414, extended for SHA-384.)
      Parameters:
      userPrivacyPassword - The user's passphrase

    • passwordToKeySHA224

      public static byte[] passwordToKeySHA224(String userPrivacyPassword)
      Converts the user's passphrase into a 28-byte SHA-224 key by hashing one megabyte of repeated passphrase data. (Based on the MD5/SHA1 approach in RFC 3414, extended for SHA-224.)
      Parameters:
      userPrivacyPassword - The user's passphrase

    • passwordToKeySHA512

      public static byte[] passwordToKeySHA512(String userPrivacyPassword)
      Converts the user's passphrase into a 64-byte SHA-512 key by hashing one megabyte of repeated passphrase data. (Based on the MD5/SHA1 approach in RFC 3414, extended for SHA-512.)
      Parameters:
      userPrivacyPassword - The user's passphrase
      Returns:
      A 64-byte derived key

    • getLocalizedKeySHA256

      public static byte[] getLocalizedKeySHA256(byte[] passwKey, String snmpEngineId)
      Converts the user's password and the SNMP Engine Id to the localized key
      Parameters:
      passwKey - The password key
      snmpEngineId - The SNMP engine Id
      Returns:
      localized key using the SHA-256 protocol

    • getLocalizedKeySHA384

      public static byte[] getLocalizedKeySHA384(byte[] passwKey, String snmpEngineId)
      Converts the user's password and the SNMP Engine Id to the localized key
      Parameters:
      passwKey - The password key
      snmpEngineId - The SNMP engine Id
      Returns:
      localized key using the SHA-384 protocol

    • getLocalizedKeySHA224

      public static byte[] getLocalizedKeySHA224(byte[] passwKey, String snmpEngineId)
      Converts the user's password and the SNMP Engine Id to the localized key
      Parameters:
      passwKey - The password key
      snmpEngineId - The SNMP engine Id
      Returns:
      localized key using the SHA-224 protocol

    • getFingerPrintSHA256

      public static byte[] getFingerPrintSHA256(byte[] key, byte[] message)
      Create a fingerprint using the SHA-256 algorithm with length 24 bytes.
      Parameters:
      key - The key to use for the first digest
      message - The message to use for the second digest
      Returns:
      The fingerprint of the message

    • getLocalizedKeySHA512

      public static byte[] getLocalizedKeySHA512(byte[] passwKey, String snmpEngineId)
      Converts the user's password and the SNMP Engine Id to the localized key using the SHA-512 protocol.
      Parameters:
      passwKey - The password key
      snmpEngineId - The SNMP engine Id
      Returns:
      localized key using the SHA-512 protocol

    • getFingerPrintSHA512

      public static byte[] getFingerPrintSHA512(byte[] key, byte[] message)
      Create a fingerprint using the SHA-512 algorithm with length 48 bytes.
      Parameters:
      key - The key to use for the first digest
      message - The message to use for the second digest
      Returns:
      The fingerprint of the message

    • getFingerPrintSHA224

      public static byte[] getFingerPrintSHA224(byte[] key, byte[] message)
      Create a fingerprint using the SHA-224 algorithm with length 28 bytes for SNMPv3.
      Parameters:
      key - The key to use for the first digest
      message - The message to use for the second digest
      Returns:
      The fingerprint of the message

    • getFingerPrintSHA384

      public static byte[] getFingerPrintSHA384(byte[] key, byte[] message)
      Create a fingerprint using the SHA-384 algorithm with length 36 bytes.
      Parameters:
      key - The key to use for the first digest
      message - The message to use for the second digest
      Returns:
      The fingerprint of the message

    • initFingerprint

      public static byte[] initFingerprint(int authenticationProtocol)
      Returns an `AsnOctets` object with a dummy fingerprint based on the authentication protocol. Returns an empty `AsnOctets` if authentication is not used.
      Parameters:
      authenticationProtocol - The authentication protocol (e.g., SHA256, SHA1, etc.).
      Returns:
      The corresponding fingerprint byte array

    • copyFingerprintToSnmpMessage

      public static void copyFingerprintToSnmpMessage(int authenticationProtocol, byte[] computedFingerprint, byte[] message, int fpPos)
      Copies the calculated fingerprint to the message at the specified position.
      Parameters:
      authenticationProtocol - The authentication protocol (e.g., SHA256, SHA1, etc.).
      computedFingerprint - The calculated fingerprint.
      message - The message to which the fingerprint will be copied.
      fpPos - The position in the message where the fingerprint will be copied.