libsodium_crypto_secretbox_xchacha20poly1305 (libsodium v3.0.1)
View SourceSecret-key authenticated encryption with XChaCha20-Poly1305, using the
same box layout as libsodium_crypto_secretbox.
easy/3 returns the macbytes/0 byte authentication tag followed by the
ciphertext, and detached/3 returns them separately. Keys are
keybytes/0 bytes and nonces noncebytes/0 bytes; the nonce can be
generated at random but must never be reused with the same key. There is
no keygen function: use libsodium_randombytes:buf/1 with
keybytes/0.
Key = libsodium_randombytes:buf(libsodium_crypto_secretbox_xchacha20poly1305:keybytes()),
Nonce = libsodium_randombytes:buf(libsodium_crypto_secretbox_xchacha20poly1305:noncebytes()),
Ciphertext = libsodium_crypto_secretbox_xchacha20poly1305:easy(<<"message">>, Nonce, Key),
<<"message">> = libsodium_crypto_secretbox_xchacha20poly1305:open_easy(Ciphertext, Nonce, Key).Summary
Types
A crypto_secretbox_xchacha20poly1305_KEYBYTES (32-byte) binary.
A crypto_secretbox_xchacha20poly1305_MACBYTES (16-byte) binary.
A crypto_secretbox_xchacha20poly1305_NONCEBYTES (24-byte) binary.
Functions
Encrypt and authenticate M with the nonce N and key K, returning
the ciphertext and the macbytes/0 byte authentication tag
separately as {C, MAC}, or -1 on failure.
Encrypt and authenticate M with the noncebytes/0 byte nonce N
and the keybytes/0 byte key K.
Return crypto_secretbox_xchacha20poly1305_keybytes(), in bytes.
Return crypto_secretbox_xchacha20poly1305_macbytes(), in bytes.
Return crypto_secretbox_xchacha20poly1305_messagebytes_max(), in bytes.
Return crypto_secretbox_xchacha20poly1305_noncebytes(), in bytes.
Verify the detached tag MAC and decrypt C with the nonce N and
key K. Returns the plaintext, or -1 when verification fails.
Verify and decrypt the ciphertext C produced by easy/3 with the
nonce N and key K. Returns the plaintext, or -1 when
verification fails or C is shorter than macbytes/0.
Types
Functions
-spec detached(M, N, K) -> Result when M :: binary(), N :: n(), K :: k(), Result :: {binary(), mac()} | -1.
Encrypt and authenticate M with the nonce N and key K, returning
the ciphertext and the macbytes/0 byte authentication tag
separately as {C, MAC}, or -1 on failure.
Encrypt and authenticate M with the noncebytes/0 byte nonce N
and the keybytes/0 byte key K.
Returns the macbytes/0 byte authentication tag followed by the
ciphertext, or -1 on failure.
-spec keybytes() -> Result when Result :: 32.
Return crypto_secretbox_xchacha20poly1305_keybytes(), in bytes.
-spec macbytes() -> Result when Result :: 16.
Return crypto_secretbox_xchacha20poly1305_macbytes(), in bytes.
-spec messagebytes_max() -> Result when Result :: non_neg_integer().
Return crypto_secretbox_xchacha20poly1305_messagebytes_max(), in bytes.
-spec noncebytes() -> Result when Result :: 24.
Return crypto_secretbox_xchacha20poly1305_noncebytes(), in bytes.
-spec open_detached(C, MAC, N, K) -> Result when C :: binary(), MAC :: mac(), N :: n(), K :: k(), Result :: binary() | -1.
Verify the detached tag MAC and decrypt C with the nonce N and
key K. Returns the plaintext, or -1 when verification fails.
Verify and decrypt the ciphertext C produced by easy/3 with the
nonce N and key K. Returns the plaintext, or -1 when
verification fails or C is shorter than macbytes/0.