Module chacha20poly1305 

ChaCha20-Poly1305 authenticated encryption

This module implements the ChaCha20-Poly1305 AEAD algorithm as specified in RFC 8439.

Constant-Time Guarantees

• No variable-length early-returns after authentication is checked.
• Heap allocations and frees are balanced in both success and failure paths.
• Authentication is decided with a branch-free constant-time mask; the same byte-wise loop executes whatever the tag’s validity.

Structs

ChaCha20Poly1305

ChaCha20-Poly1305 AEAD

ChaCha20Poly1305DecryptOperation

Operation for ChaCha20Poly1305 decryption operations

ChaCha20Poly1305EncryptOperation

Operation for ChaCha20Poly1305 encryption operations

Constants

CHACHA20POLY1305_KEY_SIZE

Size constants

CHACHA20POLY1305_NONCE_SIZE

Size of the nonce used by ChaCha20Poly1305 in bytes

CHACHA20POLY1305_TAG_SIZE

Size of the authentication tag produced by ChaCha20Poly1305 in bytes