Struct hpke::aead::AeadCtxS

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

The HPKE senders’s context. This is what you use to seal plaintexts and export secrets.

Implementations

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

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

Does a “detached seal in place”, meaning it overwrites plaintext with the resulting ciphertext, and returns the resulting authentication tag

Return Value

Returns Ok(tag) on success. If this context has been used for so many encryptions that the sequence number overflowed, returns Err(HpkeError::MessageLimitReached). If this happens, plaintext will be unmodified. If an error happened during encryption, returns Err(HpkeError::SealError). If this happens, the contents of plaintext is undefined.

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

Seals the given plaintext and returns the ciphertext

Return Value

Returns Ok(ciphertext) on success. If this context has been used for so many encryptions that the sequence number overflowed, returns Err(HpkeError::MessageLimitReached). If an error happened during encryption, returns Err(HpkeError::SealError).

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 255x the digest size (in bytes) of the underlying hash function, returns an Err(HpkeError::KdfOutputTooLong). Just don’t use to fill massive buffers and you’ll be fine.