View Source Cloak.Ciphers.AES.CTR (cloak v1.1.2)
A Cloak.Cipher which encrypts values with the AES cipher in CTR (stream) mode.
Internally relies on Erlang's :crypto.stream_encrypt/2.
Link to this section Summary
Functions
Callback implementation for Cloak.Cipher. Determines if
a ciphertext can be decrypted with this cipher.
Callback implementation for Cloak.Cipher. Decrypts a value
encrypted with AES in CTR mode.
Callback implementation for Cloak.Cipher. Encrypts a value using
AES in CTR mode.
Link to this section Functions
Callback implementation for Cloak.Cipher. Determines if
a ciphertext can be decrypted with this cipher.
Callback implementation for Cloak.Cipher. Decrypts a value
encrypted with AES in CTR mode.
Uses the key tag to find the correct key for decryption, and the IV included in the header to decrypt the body of the ciphertext.
parameters
Parameters
ciphertext- Binary ciphertext generated byencrypt/2.
examples
Examples
iex> encrypt("Hello") |> decrypt
"Hello"Callback implementation for Cloak.Cipher. Encrypts a value using
AES in CTR mode.
Generates a random IV for every encryption, and prepends the key tag and IV to the beginning of the ciphertext. The format can be diagrammed like this:
+-----------------------------------+----------------------+
| HEADER | BODY |
+-------------------+---------------+----------------------+
| Key Tag (n bytes) | IV (16 bytes) | Ciphertext (n bytes) |
+-------------------+---------------+----------------------+
| |__________________________________
| |
+---------------+-----------------+-------------------+
| Type (1 byte) | Length (1 byte) | Key Tag (n bytes) |
+---------------+-----------------+-------------------+The Key Tag component of the header breaks down into a Type, Length,
and Value triplet for easy decoding.