Crate chacha20_poly1305_aead [] [src]

A pure Rust implementation of the ChaCha20-Poly1305 AEAD from RFC 7539.

An Authenticated Encryption with Associated Data (AEAD) mode encrypts data and generates an authentication tag, or decrypts data and verifies an authentication tag, as a single operation. The tag can also validate additional authenticated data (AAD) which is not included in the cyphertext, for instance a plaintext header.

The ChaCha20-Poly1305 AEAD uses a 256-bit (32-byte) key, and a 96-bit (12-byte) nonce. For each key, a given nonce should be used only once, otherwise the encryption and authentication can be broken. One way to prevent reuse is for the nonce to contain a sequence number.

The amount of data that can be encrypted in a single call is 232 - 1 blocks of 64 bytes, slightly less than 256 GiB.



Error returned from the decrypt function.



Verifies the authentication tag and decrypts a byte slice.


Encrypts a byte slice and returns the authentication tag.


Encrypts bytes from a reader and returns the authentication tag.


Runs the self-test for ChaCha20, Poly1305, and the AEAD.