libsodium_crypto_stream (libsodium v3.0.1)
View SourceThe default stream cipher, currently XSalsa20 (see primitive/0).
crypto_stream/3 returns raw keystream and 'xor'/3 encrypts or decrypts
by combining a message with it. The noncebytes/0 byte nonce is long
enough to be chosen at random for every message.
This is not authenticated encryption: ciphertexts can be modified without
detection, so pair it with a MAC or use libsodium_crypto_secretbox
instead. A nonce must never be reused with the same key.
K = libsodium_crypto_stream:keygen(),
N = libsodium_randombytes:buf(libsodium_crypto_stream:noncebytes()),
C = libsodium_crypto_stream:'xor'(<<"message">>, N, K),
<<"message">> = libsodium_crypto_stream:'xor'(C, N, K).Summary
Functions
Return CLen bytes of keystream for the noncebytes/0 byte nonce N and the keybytes/0 byte key K.
Return crypto_stream_keybytes(), in bytes.
Generate a random keybytes/0 byte key.
Return crypto_stream_messagebytes_max(), in bytes.
Return crypto_stream_noncebytes(), in bytes.
Return crypto_stream_primitive() as an atom.
Encrypt or decrypt M by combining it with the keystream for the nonce
N and key K.
Types
Functions
-spec crypto_stream(CLen, N, K) -> Result when CLen :: non_neg_integer(), N :: n(), K :: k(), Result :: binary().
Return CLen bytes of keystream for the noncebytes/0 byte nonce N and the keybytes/0 byte key K.
-spec keybytes() -> Result when Result :: 32.
Return crypto_stream_keybytes(), in bytes.
-spec keygen() -> Result when Result :: k().
Generate a random keybytes/0 byte key.
-spec messagebytes_max() -> Result when Result :: non_neg_integer().
Return crypto_stream_messagebytes_max(), in bytes.
-spec noncebytes() -> Result when Result :: 24.
Return crypto_stream_noncebytes(), in bytes.
-spec primitive() -> Result when Result :: xsalsa20.
Return crypto_stream_primitive() as an atom.
Encrypt or decrypt M by combining it with the keystream for the nonce
N and key K.