Interface SymmetricHeaderCodec

All Known Implementing Classes:

AesHeaderCodec, ChaCha20Poly1305HeaderCodec, ChaChaHeaderCodec

public interface SymmetricHeaderCodec

Optional SPI to write/read a small header that carries runtime params (e.g., IV, tag length, AAD hash). If used, encryption will prepend the header and decryption will parse it before initializing the cipher.

Method Summary

Modifier and Type	Method	Description
InputStream	readHeader(InputStream in, CryptoAlgorithm algorithm, CtxInterface ctx)	Read header from in, populate params in ctx, and return an InputStream positioned immediately after the header.
void	writeHeader(OutputStream out, CryptoAlgorithm algorithm, CtxInterface ctx)	Writes a header to out, using or recording parameters from ctx.

Method Details

writeHeader

void writeHeader(OutputStream out,
 CryptoAlgorithm algorithm,
 CtxInterface ctx)
          throws IOException

Writes a header to out, using or recording parameters from ctx.

Parameters:

out - destination stream; remains owned by the caller

algorithm - exact symmetric algorithm whose runtime parameters are encoded

ctx - mutable operation context supplying those parameters

Throws:

IOException - if the header cannot be written

readHeader

InputStream readHeader(InputStream in,
 CryptoAlgorithm algorithm,
 CtxInterface ctx)
                throws IOException

Read header from in, populate params in ctx, and return an InputStream positioned immediately after the header.

Parameters:

in - source stream positioned at the encoded header

algorithm - exact symmetric algorithm expected by the operation

ctx - mutable operation context populated from the header

Returns:

a stream positioned at the first payload byte; ownership remains with the caller

Throws:

IOException - if the header is truncated, malformed, or cannot be read