Key material. In elliptic curve terms, a scalar.

To generate a key pair, use gen_key.

In the usual setting, the private key only be generated and used for key exchange. But it can be useful to create values of type secret with a known value, for example to check against test vectors. One can use the following pattern to do this:

 let (secret, _) = gen_key ~rng:(fun _ -> known_data) 

Generate a key pair. rng should return a Cstruct.t with the specified key length (in bytes) and fill it with random bytes.

If the cstruct returned by rng does not have the correct length, raises Failure _.

encode_secret secret is the secret encoded into a buffer.

Kind of errors.

Pretty printer for errors

Perform Diffie-Hellman key exchange between a private part and a public part.

It checks length of the pub key and returns an error if it has an incorrect length.

In DH terms, the private part corresponds to a scalar, and the public part corresponds to a point, and this computes the scalar multiplication.

The resulting shared secret is not truncated.

As described in RFC 7748, section 6.1, this function might internally generate an all-zero value. If this is the case Error `Low_order will be returned instead. This check is necessary in the context of TLS 1.3, but might not in other protocols.