@jimpick/sodium-native

sodium-native

Low level bindings for libsodium.

npm install sodium-native

The goal of this project is to be thin, stable, unopionated wrapper around libsodium.

All methods exposed are more or less a direct translation of the libsodium c-api. This means that most data types are buffers and you have to manage allocating return values and passing them in as arguments intead of receiving them as return values.

This makes this API harder to use than other libsodium wrappers out there, but also means that you'll be able to get a lot of perf / memory improvements as you can do stuff like inline encryption / decryption, re-use buffers etc.

This also makes this library useful as a foundation for more high level crypto abstractions that you want to make.

Usage

var sodium = require('sodium-native')

var nonce = new Buffer(sodium.crypto_secretbox_NONCEBYTES)
var key = sodium.sodium_malloc(sodium.crypto_secretbox_KEYBYTES) // secure buffer
var message = new Buffer('Hello, World!')
var cipher = new Buffer(message.length + sodium.crypto_secretbox_MACBYTES)

sodium.randombytes_buf(nonce) // insert random data into nonce
sodium.randombytes_buf(key)  // insert random data into key

// encrypted message is stored in cipher.
sodium.crypto_secretbox_easy(cipher, message, nonce, key)

console.log('Encrypted message:', cipher)

var plainText = new Buffer(cipher.length - sodium.crypto_secretbox_MACBYTES)

if (!sodium.crypto_secretbox_open_easy(plainText, cipher, nonce, key)) {
  console.log('Decryption failed!')
} else {
  console.log('Decrypted message:', plainText, '(' + plainText.toString() + ')')
}

API

Go to docs for the latest release (The following docs may be for a unreleased version)

var sodium = require('sodium-native')

Loads the bindings. If you get an module version error you probably need to reinstall the module because you switched node versions.

Memory Protection

Bindings to the secure memory API. See the libsodium "Securing memory allocations" docs for more information.

sodium.sodium_memzero(buffer)

Zero out the data in buffer.

sodium.sodium_mlock(buffer)

Lock the memory contained in buffer

sodium.sodium_munlock(buffer)

Unlock previously sodium_mlocked memory contained in buffer. This will also sodium_memzero buffer

var buffer = sodium.sodium_malloc(size)

Allocate a buffer of size which is memory protected. See libsodium docs for details. Be aware that many Buffer methods may break the security guarantees of sodium.sodium_malloc'ed memory. To check if a Buffer is a "secure" buffer, you can call access the getter buffer.secure which will be true.

sodium.sodium_mprotect_noaccess(buffer)

Make buffer allocated using sodium.sodium_malloc inaccessible, crashing the process if any access is attempted. Note that this will have no effect for normal Buffers.

sodium.sodium_mprotect_readonly(buffer)

Make buffer allocated using sodium.sodium_malloc read-only, crashing the process if any writing is attempted. Note that this will have no effect for normal Buffers.

sodium.sodium_mprotect_readwrite(buffer)

Make buffer allocated using sodium.sodium_malloc read-write, undoing sodium_mprotect_noaccess or sodium_mprotect_readonly. Note that this will have no effect for normal Buffers.

Generating random data

Bindings to the random data generation API. See the libsodium randombytes docs for more information.

var uint32 = sodium.randombytes_random()

Generate a random 32-bit unsigned integer [0, 0xffffffff] (both inclusive)

var uint = sodium.randombytes_uniform(upper_bound)

Generate a random 32-bit unsigned integer [0, upper_bound) (last exclusive). upper_bound must be 0xffffffff at most.

sodium.randombytes_buf(buffer)

Fill buffer with random data.

sodium.randombytes_buf_deterministic(buffer, seed)

Fill buffer with random data, generated from seed. seed must be a Buffer of at least sodium.randombytes_SEEDBYTES length

Padding

Bindings to the padding API. See the libsodium padding docs for more information.

var paddedLength = sodium.sodium_pad(buf, unpaddedLength, blocksize)

Pad buf with random data from index unpaddedLength up to closest multiple of blocksize.

• buf must be Buffer
• unpadded_buflen must be integer at most buf.length
• blocksize must be integer greater than 1 but at most buf.length

Returns the length of the padded data (so you may .slice the buffer to here).

var unpaddedLength = sodium.sodium_unpad(buf, paddedLength, blocksize)

Calculate unpaddedLength from a padded buf with blocksize

• buf must be Buffer
• padded_buflen must be integer at most buf.length
• blocksize must be integer greater than 1 but at most buf.length

Returns the length of the unpadded data (so you may .slice the buffer to here).

Signing

Bindings for the crypto_sign API. See the libsodium crypto_sign docs for more information.

crypto_sign_seed_keypair(publicKey, secretKey, seed)

Create a new keypair based on a seed.

• publicKey should be a buffer with length crypto_sign_PUBLICKEYBYTES.
• secretKey should be a buffer with length crypto_sign_SECRETKEYBYTES.
• seed should be a buffer with length crypto_sign_SEEDBYTES.

The generated public and secret key will be stored in passed in buffers.

crypto_sign_keypair(publicKey, secretKey)

Create a new keypair.

• publicKey should be a buffer with length crypto_sign_PUBLICKEYBYTES.
• secretKey should be a buffer with length crypto_sign_SECRETKEYBYTES.

The generated public and secret key will be stored in passed in buffers.

crypto_sign(signedMessage, message, secretKey)

Sign a message.

• signedMessage should be a buffer with length crypto_sign_BYTES + message.length.
• message should be a buffer of any length.
• secretKey should be a secret key.

The generated signed message will be stored in signedMessage.

var bool = crypto_sign_open(message, signedMessage, publicKey)

Verify and open a message.

• message should be a buffer with length signedMessage.length - crypto_sign_BYTES.
• signedMessage at least crypto_sign_BYTES length.
• publicKey should be a public key.

Will return true if the message could be verified. Otherwise false. If verified the originally signed message is stored in the message buffer.

crypto_sign_detached(signature, message, secretKey)

Same as crypto_sign except it only stores the signature.

• signature should be a buffer with length crypto_sign_BYTES.
• message should be a buffer of any length.
• secretKey should be a secret key.

The generated signature is stored in signature.

var bool = crypto_sign_verify_detached(signature, message, publicKey)

Verify a signature.

• signature should be a buffer with length crypto_sign_BYTES.
• message should be a buffer of any length.
• publicKey should be a public key.

Will return true if the message could be verified. Otherwise false.

crypto_sign_ed25519_pk_to_curve25519(curve_pk, ed_pk)

convert a ed25519 public key to curve25519 (which can be used with box and scalarmult)

• curve_pk should be a buffer with length crypto_box_PUBLICKEYBYTES
• ed_pk should be a buffer with length crypto_sign_PUBLICKEYBYTES

crypto_sign_ed25519_sk_to_curve25519(curve_sk, ed_sk)

convert a ed25519 secret key to curve25519 (which can be used with box and scalarmult)

• curve_sk should be a buffer with length crypto_box_SECRETKEYBYTES
• ed_sk should be a buffer with length crypto_sign_SECRETKEYBYTES

Generic hashing

Bindings for the crypto_generichash API. See the libsodium crypto_generichash docs for more information.

crypto_generichash(output, input, [key])

Hash a value with an optional key using the generichash method.

• output should be a buffer with length within crypto_generichash_BYTES_MIN - crypto_generichash_BYTES_MAX.
• input should be a buffer of any length.
• key is an optional buffer of length within crypto_generichash_KEYBYTES_MIN - crypto_generichash_KEYBYTES_MAX.

The generated hash is stored in output.

Also exposes crypto_generichash_BYTES and crypto_generichash_KEYBYTES that can be used as "default" buffer sizes.

crypto_generichash_batch(output, inputArray, [key])

Same as crypto_generichash except this hashes an array of buffers instead of a single one.

var instance = crypto_generichash_instance([key], [outputLength])

Create a generichash instance that can hash a stream of input buffers.

• key is an optional buffer as above.
• outputLength the buffer size of your output.

instance.update(input)

Update the instance with a new piece of data.

• input should be a buffer of any size.

instance.final(output)

Finalize the instance.

• output should be a buffer as above with the same length you gave when creating the instance.

The generated hash is stored in output.

Public / secret key box encryption

Bindings for the crypto_box API. See the libsodium crypto_box docs for more information.

crypto_box_seed_keypair(publicKey, secretKey, seed)

Create a new keypair based on a seed.

• publicKey should be a buffer with length crypto_box_PUBLICKEYBYTES.
• secretKey should be a buffer with length crypto_box_SECRETKEYBYTES.
• seed should be a buffer with length crypto_box_SEEDBYTES.

The generated public and secret key will be stored in passed in buffers.

crypto_box_keypair(publicKey, secretKey)

Create a new keypair.

• publicKey should be a buffer with length crypto_box_PUBLICKEYBYTES.
• secretKey should be a buffer with length crypto_box_SECRETKEYBYTES.

The generated public and secret key will be stored in passed in buffers.

crypto_box_detached(cipher, mac, message, nonce, publicKey, secretKey)

Encrypt a message.

• cipher should be a buffer with length message.length.
• mac should be a buffer with length crypto_box_MACBYTES.
• message should be a buffer of any length.
• nonce should be a buffer with length crypto_box_NONCEBYTES.
• publicKey should be a public key.
• secretKey should be a secret key.

The encrypted message will be stored in cipher and the authentification code will be stored in mac.

crypto_box_easy(cipher, message, nonce, publicKey, secretKey)

Same as crypto_box_detached except it encodes the mac in the message.

• cipher should be a buffer with length message.length + crypto_box_MACBYTES.
• message should be a buffer of any length.
• nonce should be a buffer with length crypto_box_NONCEBYTES.
• publicKey should be a public key.
• secretKey should be a secret key.

The encrypted message and authentification code will be stored in cipher.

var bool = crypto_box_open_detached(message, cipher, mac, nonce, publicKey, secretKey)

Decrypt a message.

• message should be a buffer with length cipher.length.
• mac should be a buffer with length crypto_box_MACBYTES.
• cipher should be a buffer of any length.
• nonce should be a buffer with length crypto_box_NONCEBYTES.
• publicKey should be a public key.
• secretKey should be a secret key.

Returns true if the message could be decrypted. Otherwise false.

The decrypted message will be stored in message.

var bool = crypto_box_open_easy(message, cipher, nonce, publicKey, secretKey)

Decrypt a message encoded with the easy method.

• message should be a buffer with length cipher.length - crypto_box_MACBYTES.
• cipher should be a buffer with length at least crypto_box_MACBYTES.
• nonce should be a buffer with length crypto_box_NONCEBYTES.
• publicKey should be a public key.
• secretKey should be a secret key.

Returns true if the message could be decrypted. Otherwise false.

The decrypted message will be stored in message.

Sealed box encryption

Bindings for the crypto_box_seal API. See the libsodium crypto_box_seal docs for more information.

Keypairs can be generated with crypto_box_keypair() or crypto_box_seed_keypair().

crypto_box_seal(cipher, message, publicKey)

Encrypt a message in a sealed box using a throwaway keypair. The ciphertext cannot be associated with the sender due to the sender's key being a single use keypair that is overwritten during encryption.

• cipher should be a buffer with length at least message.length + crypto_box_SEALBYTES.
• message should be a buffer with any length.
• publicKey should be the receipent's public key.

var bool = crypto_box_seal_open(message, cipher, publicKey, secretKey)

Decrypt a message encoded with the sealed box method.

• message should be a buffer with length at least cipher.length - crypto_box_SEALBYTES.
• cipher should be a buffer with length at least crypto_box_SEALBYTES.
• publicKey should be the receipient's public key.
• secretKey should be the receipient's secret key.

Note: the keypair of the recipient is required here, both public and secret key. This is because during encryption the recipient's public key is used to generate the nonce. The throwaway public key generated by the sender is stored in the first crypto_box_PUBLICKEYBYTE's of the ciphertext.

Secret key box encryption

Bindings for the crypto_secretbox API. See the libsodium crypto_secretbox docs for more information.

crypto_secretbox_detached(cipher, mac, message, nonce, secretKey)

Encrypt a message.

• cipher should be a buffer with length message.length.
• mac should be a buffer with length crypto_secretbox_MACBYTES.
• message should be a buffer of any length.
• nonce should be a buffer with length crypto_secretbox_NONCEBYTES.
• secretKey should be a secret key with legnth crypto_secretbox_KEYBYTES.

The encrypted message will be stored in cipher and the authentification code will be stored in mac.

crypto_secretbox_easy(cipher, message, nonce, secretKey)

Same as crypto_secretbox_detached except it encodes the mac in the message.

• cipher should be a buffer with length message.length + crypto_secretbox_MACBYTES.
• message should be a buffer of any length.
• nonce should be a buffer with length crypto_secretbox_NONCEBYTES.
• secretKey should be a secret key with legnth crypto_secretbox_KEYBYTES.

var bool = crypto_secretbox_open_detached(message, cipher, mac, nonce, secretKey)

Decrypt a message.

• message should be a buffer with length cipher.length.
• mac should be a buffer with length crypto_secretbox_MACBYTES.
• cipher should be a buffer of any length.
• nonce should be a buffer with length crypto_secretbox_NONCEBYTES.
• secretKey should be a secret key.

Returns true if the message could be decrypted. Otherwise false.

The decrypted message will be stored in message.

var bool = crypto_secretbox_open_easy(message, cipher, nonce, secretKey)

Decrypt a message encoded with the easy method.

• message should be a buffer with length cipher.length - crypto_secretbox_MACBYTES.
• cipher should be a buffer with length at least crypto_secretbox_MACBYTES.
• nonce should be a buffer with length crypto_secretbox_NONCEBYTES.
• secretKey should be a secret key.

Returns true if the message could be decrypted. Otherwise false.

The decrypted message will be stored in message.

Non-authenticated streaming encryption

Bindings for the crypto_stream API. See the libsodium crypto_stream docs for more information.

crypto_stream(cipher, nonce, key)

Generate random data based on a nonce and key into the cipher.

• cipher should be a buffer of any size.
• nonce should be a buffer with length crypto_stream_NONCEBYTES.
• key should be a secret key with length crypto_stream_KEYBYTES.

The generated data is stored in cipher.

crypto_stream_xor(cipher, message, nonce, key) or

crypto_stream_chacha20_xor(cipher, message, nonce, key)

Encrypt, but not authenticate, a message based on a nonce and key

• cipher should be a buffer with length message.length.
• message should be a buffer of any size.
• nonce should be a buffer with length crypto_stream_NONCEBYTES.
• key should be a secret key with length crypto_stream_KEYBYTES.

The encrypted data is stored in cipher. To decrypt, swap cipher and message. Also supports in-place encryption where you use the same buffer as cipher and message.

Encryption defaults to XSalsa20, use crypto_stream_chacha20_xor if you want to encrypt/decrypt with ChaCha20 instead.

var instance = crypto_stream_xor_instance(nonce, key) or

var instance = crypto_stream_chacha20_xor_instance(nonce, key)

A streaming instance to the crypto_stream_xor api. Pass a nonce and key in the constructor.

Encryption defaults to XSalsa20, use crypto_stream_chacha20_xor_instance if you want to encrypt/decrypt with ChaCha20 instead.

instance.update(cipher, message)

Encrypt the next message

instance.final()

Finalize the stream. Zeros out internal state.

Authentication

Bindings for the crypto_auth API. See the libsodium crypto_auth docs for more information.

crypto_auth(output, input, key)

Create an authentication token.

• output should be a buffer of length crypto_auth_BYTES.
• input should be a buffer of any size.
• key should be a buffer of lenght crypto_auth_KEYBYTES.

The generated token is stored in output.

var bool = crypto_auth_verify(output, input, key)

Verify a token.

• output should be a buffer of length crypto_auth_BYTES.
• input should be a buffer of any size.
• key should be a buffer of lenght crypto_auth_KEYBYTES.

Returns true if the token could be verified. Otherwise false.

Stream encryption

Bindings for the crypto_secretstream API. See the libsodium crypto_secretstream docs for more information.

Constants

Buffer lengths (Integer)

• crypto_secretstream_xchacha20poly1305_ABYTES
• crypto_secretstream_xchacha20poly1305_HEADERBYTES
• crypto_secretstream_xchacha20poly1305_KEYBYTES
• crypto_secretstream_xchacha20poly1305_MESSAGEBYTES_MAX
• crypto_secretstream_xchacha20poly1305_TAGBYTES - NOTE: Unofficial constant

Message tags (Buffer)

• crypto_secretstream_xchacha20poly1305_TAG_MESSAGE
• crypto_secretstream_xchacha20poly1305_TAG_PUSH
• crypto_secretstream_xchacha20poly1305_TAG_REKEY
• crypto_secretstream_xchacha20poly1305_TAG_FINAL

crypto_secretstream_xchacha20poly1305_keygen(key)

Generate a new encryption key.

• key should be a buffer of length crypto_secretstream_xchacha20poly1305_KEYBYTES.

The generated key is stored in key.

var state = crypto_secretstream_xchacha20poly1305_state_new()

Create a new stream state. Returns an opaque object used in the next methods.

crypto_secretstream_xchacha20poly1305_init_push(state, header, key)

Initialise state from the writer side with message header and encryption key key. The header must be sent or stored with the stream. The key must be exchanged securely with the receiving / reading side.

• state should be an opaque state object.
• header should be a buffer of size crypto_secretstream_xchacha20poly1305_HEADERBYTES.
• key should be a buffer of length crypto_secretstream_xchacha20poly1305_KEYBYTES.

var mlen = crypto_secretstream_xchacha20poly1305_push(state, ciphertext, message, [ad], tag)

Encrypt a message with a certain tag and optional additional data ad.

• state should be an opaque state object.
• ciphertext should be a buffer of size message.length + crypto_secretstream_xchacha20poly1305_ABYTES.
• message should be a buffer.
• ad is optional and should be null or Buffer. Included in the computation of authentication tag appended to the message.
• tag should be Buffer of length crypto_secretstream_xchacha20poly1305_TAGBYTES

Note that tag should be one of the crypto_secretstream_xchacha20poly1305_TAG_* constants. Returns number of encrypted bytes written to ciphertext.

crypto_secretstream_xchacha20poly1305_init_pull(state, header, key)

Initialise state from the reader side with message header and encryption key key. The header must be retrieved from somewhere. The key must be exchanged securely with the sending / writing side.

• state should be an opaque state object.
• header should be a buffer of size crypto_secretstream_xchacha20poly1305_HEADERBYTES.
• key should be a buffer of length crypto_secretstream_xchacha20poly1305_KEYBYTES.

var clen = crypto_secretstream_xchacha20poly1305_pull(state, message, tag, ciphertext, [ad])

Decrypt a message with optional additional data ad, and write message tag to tag. Make sure to check this!

• state should be an opaque state object.
• message should be a buffer of size ciphertext.length - crypto_secretstream_xchacha20poly1305_ABYTES.
• tag should be a buffer of crypto_secretstream_xchacha20poly1305_TAGBYTES.
• ad is optional and should be null or Buffer. Included in the computation of the authentication tag appended to the message.

Note that tag should be one of the crypto_secretstream_xchacha20poly1305_TAG_* constants. Returns number of decrypted bytes written to message.

crypto_secretstream_xchacha20poly1305_rekey(state)

Rekey the opaque state object.

One-time Authentication

Bindings for the crypto_onetimeauth API. See the libsodium crypto_onetimeauth docs for more information.

crypto_onetimeauth(output, input, key)

Create a authentication token based on a onetime key.

• output should be a buffer of length crypto_onetimauth_BYTES.
• input should be a buffer of any size.
• key should be a buffer of lenght crypto_onetimeauth_KEYBYTES.

The generated token is stored in output.

var bool = crypto_onetimeauth_verify(output, input, key)

Verify a token.

• output should be a buffer of length crypto_onetimeauth_BYTES.
• input should be a buffer of any size.
• key should be a buffer of lenght crypto_onetimeauth_KEYBYTES.

Returns true if the token could be verified. Otherwise false.

var instance = crypto_onetimeauth_instance(key)

Create an instance that create a token from a onetime key and a stream of input data.

• key should be a buffer of length crypto_onetimeauth_KEYBYTES.

instance.update(input)

Update the instance with a new piece of data.

• input should be a buffer of any size.

instance.final(output)

Finalize the instance.

• output should be a buffer of length crypto_onetimeauth_BYTES.

The generated hash is stored in output.

Password Hashing

Bindings for the crypto_pwhash API. See the libsodium crypto_pwhash docs for more information.

crypto_pwhash(output, password, salt, opslimit, memlimit, algorithm)

Create a password hash.

• output should be a buffer with length within crypto_pwhash_BYTES_MIN - crypto_pwhash_BYTES_MAX.
• password should be a buffer of any size.
• salt should be a buffer with length crypto_pwhash_SALTBYTES.
• opslimit should a be number containing your ops limit setting in the range crypto_pwhash_OPSLIMIT_MIN - crypto_pwhash_OPSLIMIT_MAX.
• memlimit should a be number containing your mem limit setting in the range crypto_pwhash_MEMLIMIT_MIN - crypto_pwhash_OPSLIMIT_MAX.
• algorithm should be a number specifying the algorithm you want to use.

Available default ops and mem limits are

• crypto_pwhash_OPSLIMIT_INTERACTIVE
• crypto_pwhash_OPSLIMIT_MODERATE
• crypto_pwhash_OPSLIMIT_SENSITIVE
• crypto_pwhash_MEMLIMIT_INTERACTIVE
• crypto_pwhash_MEMLIMIT_MODERATE
• crypto_pwhash_MEMLIMIT_SENSITIVE

The available algorithms are

• crypto_pwhash_ALG_DEFAULT
• crypto_pwhash_ALG_ARGON2ID13
• crypto_pwhash_ALG_ARGON2I13

The generated hash will be stored in output and the entire output buffer will be used.

crypto_pwhash_str(output, password, opslimit, memlimit)

Create a password hash with a random salt.

• output should be a buffer with length crypto_pwhash_STRBYTES.
• password should be a buffer of any size.
• opslimit should a be number containing your ops limit setting in the range crypto_pwhash_OPSLIMIT_MIN - crypto_pwhash_OPSLIMIT_MAX.
• memlimit should a be number containing your mem limit setting in the range crypto_pwhash_MEMLIMIT_MIN - crypto_pwhash_OPSLIMIT_MAX.

The generated hash, settings, salt, version and algorithm will be stored in output and the entire output buffer will be used.

var bool = crypto_pwhash_str_verify(str, password)

Verify a password hash generated with the above method.

• str should be a buffer with length crypto_pwhash_STRBYTES.
• password should be a buffer of any size.

Returns true if the hash could be verified with the settings contained in str. Otherwise false.

var bool = crypto_pwhash_str_needs_rehash(hash, opslimit, memlimit)

Check if a password hash needs rehash, either because the default algorithm changed, opslimit or memlimit increased or because the hash is malformed.

• hash should be a buffer with length crypto_pwhash_STRBYTES.
• opslimit should a be number containing your ops limit setting in the range crypto_pwhash_OPSLIMIT_MIN - crypto_pwhash_OPSLIMIT_MAX.
• memlimit should a be number containing your mem limit setting in the range crypto_pwhash_MEMLIMIT_MIN - crypto_pwhash_OPSLIMIT_MAX.

Returns true if the hash should be rehashed the settings contained in str. Otherwise false if it is still good.

crypto_pwhash_async(output, password, salt, opslimit, memlimit, algorithm, callback)

Just like crypto_pwhash but will run password hashing on a seperate worker so it will not block the event loop. callback(err) will receive any errors from the hashing but all argument errors will throw. The resulting hash is written to output. This function also supports async_hooks as the type sodium-native:crypto_pwhash_async

crypto_pwhash_str_async(output, password, opslimit, memlimit, callback)

Just like crypto_pwhash_str but will run password hashing on a seperate worker so it will not block the event loop. callback(err) will receive any errors from the hashing but all argument errors will throw. The resulting hash with parameters is written to output. This function also supports async_hooks as the type sodium-native:crypto_pwhash_str_async

crypto_pwhash_str_verify_async(str, password, callback)

Just like crypto_pwhash_str_verify but will run password hashing on a seperate worker so it will not block the event loop. callback(err, bool) will receive any errors from the hashing but all argument errors will throw. If the verification succeeds bool is true, otherwise false. Due to an issue with libsodium err is currently never set. This function also supports async_hooks as the type sodium-native:crypto_pwhash_str_verify_async

Key exchange

Bindings for the crypto_kx API. See the libsodium crypto_kx docs for more information.

crypto_kx_keypair(publicKey, secretKey)

Create a key exchange key pair.

• publicKey should be a buffer of length crypto_kx_PUBLICKEYBYTES.
• secretKey should be a buffer of length crypto_kx_SECRETKEYBYTES.

crypto_kx_seed_keypair(publicKey, secretKey, seed)

Create a key exchange key pair based on a seed.

• publicKey should be a buffer of length crypto_kx_PUBLICKEYBYTES.
• secretKey should be a buffer of length crypto_kx_SECRETKEYBYTES.
• seed should be a buffer of length crypto_kx_SEEDBYTES

crypto_kx_client_session_keys(rx, tx, clientPublicKey, clientSecretKey, serverPublicKey)

Generate a session receive and transmission key for a client. The public / secret keys should be generated using the key pair method above.

• rx should be a buffer of length crypto_kx_SESSIONKEYBYTES.
• tx should be a buffer of length crypto_kx_SESSIONKEYBYTES.

You should use the rx to decrypt incoming data and tx to encrypt outgoing.

crypto_kx_server_session_keys(rx, tx, serverPublicKey, serverSecretKey, clientPublicKey)

Generate a session receive and transmission key for a server. The public / secret keys should be generated using the key pair method above.

• rx should be a buffer of length crypto_kx_SESSIONKEYBYTES.
• tx should be a buffer of length crypto_kx_SESSIONKEYBYTES.

You should use the rx to decrypt incoming data and tx to encrypt outgoing.

Scalar multiplication

Bindings for the crypto_scalarmult API. See the libsodium crypto_scalarmult docs for more information.

crypto_scalarmult_base(publicKey, secretKey)

Create a scalar multiplication public key based on a secret key

• publicKey should be a buffer of length crypto_scalarmult_BYTES.
• secretKey should be a buffer of length crypto_scalarmult_SCALARBYTES.

The generated public key is stored in publicKey.

crypto_scalarmult(sharedSecret, secretKey, remotePublicKey)

Derive a shared secret from a local secret key and a remote public key.

• sharedSecret shoudl be a buffer of length crypto_scalarmult_BYTES.
• secretKey should be a buffer of length crypto_scalarmult_SCALARBYTES.
• remotePublicKey should be a buffer of length crypto_scalarmult_BYTES.

The generated shared secret is stored in sharedSecret.

Short hashes

Bindings for the crypto_shorthash API. See the libsodium crypto_shorthash docs for more information.

crypto_shorthash(output, input, key)

Hash a value to a short hash based on a key.

• output should be a buffer of length crypto_shorthash_BYTES.
• input should be a buffer of any size.
• key should be a buffer of length crypto_shorthash_KEYBYTES.

The generated short hash is stored in output.

Key derivation

Bindings for the crypto_kdf API. See the libsodium crypto_kdf docs for more information.

crypto_kdf_keygen(key)

Generate a new master key.

• key should be a buffer of length crypto_kdf_KEYBYTES

crypto_kdf_derive_from_key(subkey, subkeyId, context, key)

Derive a new key from a master key.

• subkey should be a buffer between crypto_kdf_BYTES_MIN and crypto_kdf_BYTES_MAX.
• subkeyId should be an integer.
• context should be a buffer of length crypto_kdf_CONTEXTBYTES
• key should by a buffer of length crypto_kdf_KEYBYTES

SHA

crypto_hash_sha256(output, input)

Hash a value to a short hash based on a key.

• output should be a buffer of length crypto_hash_sha256_BYTES.
• input should be a buffer of any size.

The generated short hash is stored in output.

var instance = crypto_hash_sha256_instance()

Create an instance that has stream of input data to sha256.

instance.update(input)

Update the instance with a new piece of data.

• input should be a buffer of any size.

instance.final(output)

Finalize the instance.

• output should be a buffer of length crypto_hash_sha256_BYTES.

The generated hash is stored in output.

crypto_hash_sha512(output, input)

Hash a value to a short hash based on a key.

• output should be a buffer of length crypto_hash_sha512_BYTES.
• input should be a buffer of any size.

The generated short hash is stored in output.

var instance = crypto_hash_sha512_instance()

Create an instance that has stream of input data to sha512.

instance.update(input)

Update the instance with a new piece of data.

• input should be a buffer of any size.

instance.final(output)

Finalize the instance.

• output should be a buffer of length crypto_hash_sha512_BYTES.

The generated hash is stored in output.

License

MIT