Module com.southernstorm.noise
Package com.southernstorm.noise.protocol

Class SymmetricState

java.lang.Object
com.southernstorm.noise.protocol.SymmetricState
All Implemented Interfaces:
Destroyable
public class SymmetricState extends Object implements Destroyable
Symmetric state for helping manage a Noise handshake.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    protected CipherState
    cipher
     
    protected byte[]
    ck
     
    protected byte[]
    h
     
    protected MessageDigest
    hash
     
    protected String
    name
     
    protected byte[]
    prev_h
     

  • Constructor Summary

    Constructors
    Constructor
    Description
    SymmetricState​(String protocolName, String cipherName, String hashName)
    Constructs a new symmetric state object.

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    decryptAndHash​(byte[] ciphertext, int ciphertextOffset, byte[] plaintext, int plaintextOffset, int length)
    Decrypts a block of ciphertext and mixes it into the handshake hash.
    void
    destroy()
    Destroys all sensitive state in the current object.
    int
    encryptAndHash​(byte[] plaintext, int plaintextOffset, byte[] ciphertext, int ciphertextOffset, int length)
    Encrypts a block of plaintext and mixes the ciphertext into the handshake hash.
    byte[]
    getHandshakeHash()
    Gets the current value of the handshake hash.
    int
    getMACLength()
    Gets the length of MAC values in the current state.
    String
    getProtocolName()
    Gets the name of the Noise protocol.
    void
    mixHash​(byte[] data, int offset, int length)
    Mixes data into the handshake hash.
    void
    mixKey​(byte[] data, int offset, int length)
    Mixes data into the chaining key.
    void
    mixPreSharedKey​(byte[] key)
    Mixes a pre-shared key into the chaining key and handshake hash.
    void
    mixPublicKey​(DHState dh)
    Mixes a pre-supplied public key into the handshake hash.
    void
    mixPublicKeyIntoCK​(DHState dh)
    Mixes a pre-supplied public key into the chaining key.
    CipherStatePair
    split()
    Splits the symmetric state into two ciphers for session encryption.
    CipherStatePair
    split​(byte[] secondaryKey, int offset, int length)
    Splits the symmetric state into two ciphers for session encryption, and optionally mixes in a secondary symmetric key.

    Methods inherited from class java.lang.Object

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

  • Field Details

    • name

      protected final String name

    • cipher

      protected CipherState cipher

    • hash

      protected MessageDigest hash

    • ck

      protected byte[] ck

    • h

      protected byte[] h

    • prev_h

      protected byte[] prev_h

  • Constructor Details

    • SymmetricState

      public SymmetricState​(String protocolName, String cipherName, String hashName) throws NoSuchAlgorithmException
      Constructs a new symmetric state object.
      Parameters:
      protocolName - The name of the Noise protocol, which is assumed to be valid.
      cipherName - The name of the cipher within protocolName.
      hashName - The name of the hash within protocolName.
      Throws:
      NoSuchAlgorithmException - The cipher or hash algorithm in the protocol name is not supported.

  • Method Details

    • getProtocolName

      public String getProtocolName()
      Gets the name of the Noise protocol.
      Returns:
      The protocol name.

    • getMACLength

      public int getMACLength()
      Gets the length of MAC values in the current state.
      Returns:
      The length of the MAC value for the underlying cipher or zero if the cipher has not yet been initialized with a key.

    • mixKey

      public void mixKey​(byte[] data, int offset, int length)
      Mixes data into the chaining key.
      Parameters:
      data - The buffer containing the data to mix in.
      offset - The offset of the first data byte to mix in.
      length - The number of bytes to mix in.

    • mixHash

      public void mixHash​(byte[] data, int offset, int length)
      Mixes data into the handshake hash.
      Parameters:
      data - The buffer containing the data to mix in.
      offset - The offset of the first data byte to mix in.
      length - The number of bytes to mix in.

    • mixPreSharedKey

      public void mixPreSharedKey​(byte[] key)
      Mixes a pre-shared key into the chaining key and handshake hash.
      Parameters:
      key - The pre-shared key value.

    • mixPublicKey

      public void mixPublicKey​(DHState dh)
      Mixes a pre-supplied public key into the handshake hash.
      Parameters:
      dh - The object containing the public key.

    • mixPublicKeyIntoCK

      public void mixPublicKeyIntoCK​(DHState dh)
      Mixes a pre-supplied public key into the chaining key.
      Parameters:
      dh - The object containing the public key.

    • encryptAndHash

      public int encryptAndHash​(byte[] plaintext, int plaintextOffset, byte[] ciphertext, int ciphertextOffset, int length) throws ShortBufferException
      Encrypts a block of plaintext and mixes the ciphertext into the handshake hash.
      Parameters:
      plaintext - The buffer containing the plaintext to encrypt.
      plaintextOffset - The offset within the plaintext buffer of the first byte or plaintext data.
      ciphertext - The buffer to place the ciphertext in. This can be the same as the plaintext buffer.
      ciphertextOffset - The first offset within the ciphertext buffer to place the ciphertext and the MAC tag.
      length - The length of the plaintext.
      Returns:
      The length of the ciphertext plus the MAC tag.
      Throws:
      ShortBufferException

    • decryptAndHash

      public int decryptAndHash​(byte[] ciphertext, int ciphertextOffset, byte[] plaintext, int plaintextOffset, int length) throws ShortBufferException, BadPaddingException
      Decrypts a block of ciphertext and mixes it into the handshake hash.
      Parameters:
      ciphertext - The buffer containing the ciphertext to decrypt.
      ciphertextOffset - The offset within the ciphertext buffer of the first byte of ciphertext data.
      plaintext - The buffer to place the plaintext in. This can be the same as the ciphertext buffer.
      plaintextOffset - The first offset within the plaintext buffer to place the plaintext.
      length - The length of the incoming ciphertext plus the MAC tag.
      Returns:
      The length of the plaintext with the MAC tag stripped off.
      Throws:
      ShortBufferException - There is not enough space in the plaintext buffer for the decrypted data.
      BadPaddingException - The MAC value failed to verify.

      The plaintext and ciphertext buffers can be the same for in-place decryption. In that case, ciphertextOffset must be identical to plaintextOffset.

    • split

      public CipherStatePair split()
      Splits the symmetric state into two ciphers for session encryption.
      Returns:
      The pair of ciphers for sending and receiving.

    • split

      public CipherStatePair split​(byte[] secondaryKey, int offset, int length)
      Splits the symmetric state into two ciphers for session encryption, and optionally mixes in a secondary symmetric key.
      Parameters:
      secondaryKey - The buffer containing the secondary key.
      offset - The offset of the first secondary key byte.
      length - The length of the secondary key in bytes, which must be either 0 or 32.
      Returns:
      The pair of ciphers for sending and receiving.
      Throws:
      IllegalArgumentException - The length is not 0 or 32.

    • getHandshakeHash

      public byte[] getHandshakeHash()
      Gets the current value of the handshake hash.
      Returns:
      The handshake hash. This must not be modified by the caller.

      The handshake hash value is only of use to the application after split() has been called.

    • destroy

      public void destroy()
      Description copied from interface: Destroyable
      Destroys all sensitive state in the current object.
      Specified by:
      destroy in interface Destroyable