Package chacha20poly1305 implements the ChaCha20-Poly1305 AEAD and its extended nonce variant XChaCha20-Poly1305, as specified in RFC 8439 and draft-irtf-cfrg-xchacha-01.
const ( // KeySize is the size of the key used by this AEAD, in bytes. KeySize = 32 // NonceSize is the size of the nonce used with the standard variant of this // AEAD, in bytes. // // Note that this is too short to be safely generated at random if the same // key is reused more than 2³² times. NonceSize = 12 // NonceSizeX is the size of the nonce used with the XChaCha20-Poly1305 // variant of this AEAD, in bytes. NonceSizeX = 24 )
New returns a ChaCha20-Poly1305 AEAD that uses the given 256-bit key.
NewX returns a XChaCha20-Poly1305 AEAD that uses the given 256-bit key.
XChaCha20-Poly1305 is a ChaCha20-Poly1305 variant that takes a longer nonce, suitable to be generated randomly without risk of collisions. It should be preferred when nonce uniqueness cannot be trivially ensured, or whenever nonces are randomly generated.