Struct hpke::aead::AeadCtxR

pub struct AeadCtxR<A: Aead, Kdf: KdfTrait, Kem: KemTrait>(_);

The HPKE receiver’s context. This is what you use to open ciphertexts and export secrets.

Implementations

impl<A: Aead, Kdf: KdfTrait, Kem: KemTrait> AeadCtxR<A, Kdf, Kem>

pub fn open_in_place_detached( &mut self, ciphertext: &mut [u8], aad: &[u8], tag: &AeadTag<A> ) -> Result<(), HpkeError>

Does a “detached open in place”, meaning it overwrites ciphertext with the resulting plaintext, and takes the tag as a separate input.

Return Value

Returns Ok(()) on success. If this context has been used for so many encryptions that the sequence number overflowed, returns Err(HpkeError::MessageLimitReached). If this happens, ciphertext will be unmodified. If the tag fails to validate, returns Err(HpkeError::OpenError). If this happens, ciphertext is in an undefined state.

pub fn open( &mut self, ciphertext: &[u8], aad: &[u8] ) -> Result<Vec<u8>, HpkeError>

Opens the given ciphertext and returns a plaintext

Return Value

Returns Ok(()) on success. If this context has been used for so many encryptions that the sequence number overflowed, returns Err(HpkeError::MessageLimitReached). If the tag fails to validate, returns Err(HpkeError::OpenError).

pub fn export(&self, info: &[u8], out_buf: &mut [u8]) -> Result<(), HpkeError>

Fills a given buffer with secret bytes derived from this encryption context. This value does not depend on sequence number, so it is constant for the lifetime of this context.

Return Value

Returns Ok(()) on success. If the buffer length is more than about 255x the digest size (in bytes) of the underlying hash function, returns an Err(HpkeError::KdfOutputTooLong). The exact number is given in the “Input Length Restrictions” section of the spec. Just don’t use to fill massive buffers and you’ll be fine.