Signing

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

Constants

Buffer lengths (integer)

• crypto_sign_PUBLICKEYBYTES
• crypto_sign_SECRETKEYBYTES
• crypto_sign_SEEDBYTES
• crypto_sign_BYTES
• crypto_box_PUBLICKEYBYTES
• crypto_box_SECRETKEYBYTES

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crypto_sign_seed25519_keypair

sodium.crypto_sign_seed25519_keypair(pk, sk, seed)

Creates a new keypair based on a seed.

• pk should be a buffer of length crypto_sign_PUBLICKEYBYTES
• sk should be a buffer of length crypto_sign_SECRETKEYBYTES
• seed should be a buffer of length crypto_sign_SEEDBYTES

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

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crypto_sign_keypair

sodium.crypto_sign_keypair(pk, sk)

Creates a new keypair.

• pk should be a buffer of length crypto_sign_PUBLICKEYBYTES
• sk should be a buffer of length crypto_sign_SECRETKEYBYTES

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

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crypto_sign

sodium.crypto_sign(sm, m, sk)

Signs a message.

• sm should be a buffer of length crypto_sign_BYTES + m.length
• m should be a buffer of any length
• sk should be a secret key

The generated signed message will be stored in sm.

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crypto_sign_open

var bool = sodium.crypto_sign_open(m, sm, pk)

Verifies and opens a message.

• m should be a buffer of length sm.length - crypto_sign_BYTES
• sm of length at least crypto_sign_BYTES
• pk 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.

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crypto_sign_detached

sodium.crypto_sign_detached(sig, m, sk)

Same as crypto_sign, except that it only stores the signature.

• sig should be a buffer of length crypto_sign_BYTES
• m should be a buffer of any length
• sk should be a secret key

The generated signature is stored in signature.

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crypto_sign_verify_detached

var bool = sodium.crypto_sign_verify_detached(sig, m, pk)

Verifies a signature.

• sig should be a buffer of length crypto_sign_BYTES
• m should be a buffer of any length
• pk should be a public key

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

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crypto_sign_ed25519_pk_to_curve25519

sodium.crypto_sign_ed25519_pk_to_curve25519(x25519_pk, ed25519_pk)

Converts an ed25519 public key to curve25519 (which can be used with box and scalarmult).

• x25519_pk should be a buffer of length crypto_box_PUBLICKEYBYTES
• ed25519_pk should be a buffer of length crypto_sign_PUBLICKEYBYTES

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crypto_sign_ed25519_sk_to_curve25519

sodium.crypto_sign_ed25519_sk_to_curve25519(x25519_sk, ed25519_sk)

Converts an ed25519 secret key to curve25519 (which can be used with box and scalarmult).

• x25519_sk should be a buffer of length crypto_box_SECRETKEYBYTES
• ed25519_sk should be a buffer of length crypto_sign_SECRETKEYBYTES

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crypto_sign_ed25519_sk_to_pk

sodium.crypto_sign_ed25519_sk_to_pk(pk, sk)

Extracts an ed25519 public key from an ed25519 secret key.

• pk must be a buffer of at least crypto_box_PUBLICKEYBYTES bytes
• sk must be a buffer of at least crypto_sign_SECRETKEYBYTES bytes