//! Signature for authenticity of data
use holo_hash::AgentPubKey;
use holochain_serialized_bytes::prelude::*;
/// Ed25519 signatures are always the same length, 64 bytes.
pub const SIGNATURE_BYTES: usize = 64;
/// The raw bytes of a signature.
#[derive(Clone, PartialOrd, Hash, Ord)]
// The equality is not different, it's just constant time, so we can derive a hash.
// For an actually secure thing we wouldn't want to just assume a safe default hashing
// But that is not what clippy is complaining about here.
#[allow(clippy::derive_hash_xor_eq)]
pub struct Signature(pub [u8; SIGNATURE_BYTES]);
#[cfg(feature = "arbitrary")]
impl<'a> arbitrary::Arbitrary<'a> for Signature {
fn arbitrary(u: &mut arbitrary::Unstructured<'a>) -> arbitrary::Result<Self> {
let mut buf = [0; SIGNATURE_BYTES];
u.fill_buffer(&mut buf)?;
Ok(Signature(buf))
}
}
// This is more for convenience/convention that being worried
// about things like constant time equality.
// Signature verification should always defer to the host.
// What's nice about this is that we can easily handle fixed size signatures.
crate::secure_primitive!(Signature, SIGNATURE_BYTES);
/// The output of ephemeral signing.
/// The private key for this public key has been discarded by this point.
/// The signatures match the public key provided but cannot be reproduced
/// or forged because the private key no longer exists.
/// The signatures match the input items positionally in the vector,
/// it is up to the caller to reconstruct/align/zip them back together.
#[derive(Serialize, Deserialize, Debug, Clone, PartialEq)]
pub struct EphemeralSignatures {
/// The public key associated with the now-discarded private key used to sign.
pub key: holo_hash::AgentPubKey,
/// The signatures for the input data to be matched in order, pairwise.
pub signatures: Vec<Signature>,
}
/// Mirror struct for Sign that includes a signature to verify against a key and data.
#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, SerializedBytes)]
pub struct VerifySignature {
/// The public key associated with the private key that should be used to
/// verify the signature.
pub key: holo_hash::AgentPubKey,
/// The signature being verified.
pub signature: Signature,
/// The signed data
#[serde(with = "serde_bytes")]
pub data: Vec<u8>,
}
impl AsRef<Signature> for VerifySignature {
fn as_ref(&self) -> &Signature {
&self.signature
}
}
impl AsRef<holo_hash::AgentPubKey> for VerifySignature {
fn as_ref(&self) -> &AgentPubKey {
&self.key
}
}
impl VerifySignature {
/// Alias for as_ref for data.
pub fn as_data_ref(&self) -> &[u8] {
self.data.as_ref()
}
/// Alias for as_ref for signature.
pub fn as_signature_ref(&self) -> &Signature {
self.as_ref()
}
/// Alias for as_ref for agent key.
pub fn as_key_ref(&self) -> &holo_hash::AgentPubKey {
self.as_ref()
}
/// construct a new VerifySignature struct.
pub fn new<D>(
key: holo_hash::AgentPubKey,
signature: Signature,
data: D,
) -> Result<Self, SerializedBytesError>
where
D: serde::Serialize + std::fmt::Debug,
{
Ok(Self {
key,
signature,
data: holochain_serialized_bytes::encode(&data)?,
})
}
/// construct a new Sign struct from raw bytes.
pub fn new_raw(key: holo_hash::AgentPubKey, signature: Signature, data: Vec<u8>) -> Self {
Self {
key,
signature,
data,
}
}
}