keepass::encrypt_ostreambuf Class Reference

Input streambuf that encrypts on the fly (streaming counterpart of the whole-buffer encrypt_cbc / ChaCha20 path). More...

#include <stream.hh>

Inheritance diagram for keepass::encrypt_ostreambuf:

Public Member Functions
	encrypt_ostreambuf (std::ostream &dst, Cipher< 16 > &cipher)
	Constructs a CBC-mode encrypting streambuf.
	encrypt_ostreambuf (std::ostream &dst, ChaCha20Cipher &cipher)
	Constructs a ChaCha20 encrypting streambuf.
	~encrypt_ostreambuf () override
	Zeroizes the transient plaintext and chaining state.
int	overflow (int c) override
	Buffers a character, encrypting one block when it reaches capacity.
std::streamsize	xsputn (const char *s, std::streamsize count) override
	Writes several characters, applying cipher respectively.
int	sync () override
	Finalizes the stream (PKCS #7 padding for CBC, partial block for ChaCha20).

Detailed Description

Input streambuf that encrypts on the fly (streaming counterpart of the whole-buffer encrypt_cbc / ChaCha20 path).

Wraps the plaintext in the same ciphertext produced by the existing blocking code: CBC mode with PKCS #7 padding for block ciphers and pure XOR with a 64-byte keystream for ChaCha20. This lets the exporters pipe the XML (and KDBX 4 inner header) directly into the cipher without ever materializing the plaintext or ciphertext in memory.

Constructor & Destructor Documentation

encrypt_ostreambuf() [1/2]

keepass::encrypt_ostreambuf::encrypt_ostreambuf	(	std::ostream &	dst,
		Cipher< 16 > &	cipher
	)

Constructs a CBC-mode encrypting streambuf.

Parameters

dst	The output stream receiving the ciphertext.
cipher	The 16-byte block cipher used for CBC encryption.

encrypt_ostreambuf() [2/2]

keepass::encrypt_ostreambuf::encrypt_ostreambuf	(	std::ostream &	dst,
		ChaCha20Cipher &	cipher
	)

Constructs a ChaCha20 encrypting streambuf.

Parameters

dst	The output stream receiving the ciphertext.
cipher	The ChaCha20 cipher used for keystream generation.

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The documentation for this class was generated from the following file:

• stream.hh