ChaCha20 Class Reference

A class for ChaCha20 256-bit stream cipher developed by Daniel J. More...

#include <chacha20.h>

Public Member Functions
	ChaCha20 ()
	ChaCha20 (const unsigned char *key, size_t keylen)
void	SetKey (const unsigned char *key, size_t keylen)
	set key with flexible keylength; 256bit recommended */ More...
void	SetIV (uint64_t iv)
void	Seek (uint64_t pos)
void	Keystream (unsigned char *c, size_t bytes)
	outputs the keystream of size <bytes> into More...
void	Crypt (const unsigned char *input, unsigned char *output, size_t bytes)
	enciphers the message <input> of length <bytes> and write the enciphered representation into <output> Used for encryption and decryption (XOR) More...

Private Attributes
uint32_t	input [16]

Detailed Description

A class for ChaCha20 256-bit stream cipher developed by Daniel J.

Bernstein https://cr.yp.to/chacha/chacha-20080128.pdf

Definition at line 13 of file chacha20.h.

Constructor & Destructor Documentation

ChaCha20() [1/2]

ChaCha20::ChaCha20

(

)

Definition at line 52 of file chacha20.cpp.

References input.

ChaCha20() [2/2]

ChaCha20::ChaCha20	(	const unsigned char *	key,
		size_t	keylen
	)

Definition at line 57 of file chacha20.cpp.

References SetKey().

Member Function Documentation

Crypt()

void ChaCha20::Crypt	(	const unsigned char *	input,
		unsigned char *	output,
		size_t	bytes
	)

enciphers the message <input> of length <bytes> and write the enciphered representation into <output> Used for encryption and decryption (XOR)

Definition at line 182 of file chacha20.cpp.

References input, QUARTERROUND, ReadLE32(), and WriteLE32().

Referenced by ChaCha20Poly1305AEAD::Crypt().

Keystream()

void ChaCha20::Keystream	(	unsigned char *	c,
		size_t	bytes
	)

outputs the keystream of size <bytes> into

Definition at line 74 of file chacha20.cpp.

References input, QUARTERROUND, and WriteLE32().

Referenced by ChaCha20Poly1305AEAD::Crypt(), FastRandomContext::FillByteBuffer(), ChaCha20Poly1305AEAD::GetLength(), and FastRandomContext::randbytes().

Seek()

void ChaCha20::Seek

(

uint64_t

pos

)

Definition at line 68 of file chacha20.cpp.

References input.

Referenced by ChaCha20Poly1305AEAD::Crypt(), and ChaCha20Poly1305AEAD::GetLength().

SetIV()

void ChaCha20::SetIV

(

uint64_t

iv

)

Definition at line 62 of file chacha20.cpp.

References input.

Referenced by ChaCha20Poly1305AEAD::Crypt(), and ChaCha20Poly1305AEAD::GetLength().

SetKey()

void ChaCha20::SetKey	(	const unsigned char *	key,
		size_t	keylen
	)

set key with flexible keylength; 256bit recommended */

Definition at line 24 of file chacha20.cpp.

References input, ReadLE32(), sigma, and tau.

Referenced by ChaCha20(), ChaCha20Poly1305AEAD::ChaCha20Poly1305AEAD(), FastRandomContext::FastRandomContext(), and FastRandomContext::RandomSeed().

Member Data Documentation

input

uint32_t ChaCha20::input[16]

private

Definition at line 16 of file chacha20.h.

Referenced by ChaCha20(), Crypt(), Keystream(), Seek(), SetIV(), and SetKey().

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

• src/crypto/chacha20.h
• src/crypto/chacha20.cpp