Module aead::stream

Available on crate feature stream only.

Streaming AEAD support.

Implementation of the STREAM online authenticated encryption construction as described in the paper Online Authenticated-Encryption and its Nonce-Reuse Misuse-Resistance.

About

The STREAM construction supports encrypting/decrypting sequences of AEAD message segments, which is useful in cases where the overall message is too large to fit in a single buffer and needs to be processed incrementally.

STREAM defends against reordering and truncation attacks which are common in naive schemes which attempt to provide these properties, and is proven to meet the security definition of “nonce-based online authenticated encryption” (nOAE) as given in the aforementioned paper.

Diagram

Legend:

• 𝐄k: AEAD encryption under key k
• 𝐌: message
• 𝐍: nonce
• 𝐀: additional associated data
• 𝐂: ciphertext
• 𝜏: MAC tag

Structs

• Decryptor
  Stateful STREAM object which can decrypt AEAD messages one-at-a-time.
• Encryptor
  Stateful STREAM object which can encrypt AEAD messages one-at-a-time.
• StreamBE32
  The original “Rogaway-flavored” STREAM as described in the paper Online Authenticated-Encryption and its Nonce-Reuse Misuse-Resistance.
• StreamLE31
  STREAM as instantiated with a 31-bit little endian counter and 1-bit “last block” flag stored as the most significant bit of the counter when interpreted as a 32-bit integer.

Traits

• NewStream
  Create a new STREAM from the provided AEAD.
• StreamPrimitive
  Low-level STREAM implementation.

Type Definitions

• DecryptorBE32
  STREAM decryptor instantiated with StreamBE32 as the underlying STREAM primitive.
• DecryptorLE31
  STREAM decryptor instantiated with StreamLE31 as the underlying STREAM primitive.
• EncryptorBE32
  STREAM encryptor instantiated with StreamBE32 as the underlying STREAM primitive.
• EncryptorLE31
  STREAM encryptor instantiated with StreamLE31 as the underlying STREAM primitive.
• Nonce
  Nonce as used by a given AEAD construction and STREAM primitive.
• NonceSize
  Size of a nonce as used by a STREAM construction, sans the overhead of the STREAM protocol itself.