com.google.crypto.tink.subtle

Interface StreamSegmentEncrypter

public interface StreamSegmentEncrypter

StreamSegmentEncrypter is a helper class that encrypts individual segments of a stream.

Instances of this interfaces are passed to ...EncryptingChannel. Each instance of a segment encrypter is used to encrypt one stream. Typically, constructing a new StreamSegmentEncrypter results in the generation of a new symmetric key. This new symmetric key is used to encrypt the segments of the stream. The key itself wrapped with or derived from the key from StreamingAead instance. The wrapped key or the salt used to derive the symmetric key is part of the header.

A StreamSegmentEncrypter has a state: it keeps the number of segments encrypted so far. This state is used to encrypt each segment with different parameters, so that segments in the ciphertext cannot be switched.

Since:

1.1.0

Method Summary

Modifier and Type	Method and Description
void	encryptSegment(ByteBuffer plaintext, boolean isLastSegment, ByteBuffer ciphertext) Encrypts the next plaintext segment.
void	encryptSegment(ByteBuffer part1, ByteBuffer part2, boolean isLastSegment, ByteBuffer ciphertext) Encrypt a segment consisting of two parts.
ByteBuffer	getHeader() Returns the header of the ciphertext stream.

Method Detail

getHeader

ByteBuffer getHeader()

Returns the header of the ciphertext stream.

encryptSegment

void encryptSegment(ByteBuffer plaintext,
                    boolean isLastSegment,
                    ByteBuffer ciphertext)
             throws GeneralSecurityException

Encrypts the next plaintext segment. This uses encryptedSegments as the segment number for the encryption.

Throws:

GeneralSecurityException

encryptSegment

void encryptSegment(ByteBuffer part1,
                    ByteBuffer part2,
                    boolean isLastSegment,
                    ByteBuffer ciphertext)
             throws GeneralSecurityException

Encrypt a segment consisting of two parts. This method simplifies the case where one part of the plaintext is buffered and the other part is passed in by the caller.

Throws:

GeneralSecurityException