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use ContextFlag;
use Error;
use Message;
use Secp256k1;
use constants;
use ffi;
use key::{SecretKey, PublicKey};
use std::{mem, ptr};
use std::convert::From;
pub struct Signature([u8; constants::SCHNORR_SIGNATURE_SIZE]);
impl_array_newtype!(Signature, u8, constants::SCHNORR_SIGNATURE_SIZE);
impl_pretty_debug!(Signature);
impl Signature {
pub fn deserialize(data: &[u8]) -> Signature {
assert_eq!(data.len(), constants::SCHNORR_SIGNATURE_SIZE);
let mut ret = [0; constants::SCHNORR_SIGNATURE_SIZE];
ret[..].copy_from_slice(data);
Signature(ret)
}
pub fn serialize(&self) -> Vec<u8> {
Vec::from(&self.0[..])
}
}
impl Secp256k1 {
pub fn sign_schnorr(&self, msg: &Message, sk: &SecretKey) -> Result<Signature, Error> {
if self.caps == ContextFlag::VerifyOnly || self.caps == ContextFlag::None {
return Err(Error::IncapableContext);
}
let mut ret: Signature = unsafe { mem::uninitialized() };
unsafe {
let err = ffi::secp256k1_schnorr_sign(self.ctx, ret.as_mut_ptr(), msg.as_ptr(),
sk.as_ptr(), ffi::secp256k1_nonce_function_rfc6979,
ptr::null());
debug_assert_eq!(err, 1);
}
Ok(ret)
}
pub fn verify_schnorr(&self, msg: &Message, sig: &Signature, pk: &PublicKey) -> Result<(), Error> {
if self.caps == ContextFlag::SignOnly || self.caps == ContextFlag::None {
return Err(Error::IncapableContext);
}
if !pk.is_valid() {
Err(Error::InvalidPublicKey)
} else if unsafe { ffi::secp256k1_schnorr_verify(self.ctx, sig.as_ptr(), msg.as_ptr(),
pk.as_ptr()) } == 0 {
Err(Error::IncorrectSignature)
} else {
Ok(())
}
}
pub fn recover_schnorr(&self, msg: &Message, sig: &Signature)
-> Result<PublicKey, Error> {
if self.caps == ContextFlag::SignOnly || self.caps == ContextFlag::None {
return Err(Error::IncapableContext);
}
let mut pk = unsafe { ffi::PublicKey::blank() };
unsafe {
if ffi::secp256k1_schnorr_recover(self.ctx, &mut pk,
sig.as_ptr(), msg.as_ptr()) != 1 {
return Err(Error::InvalidSignature);
}
};
Ok(PublicKey::from(pk))
}
}
#[cfg(test)]
mod tests {
use rand::{Rng, thread_rng};
use ContextFlag;
use Message;
use Secp256k1;
use Error::IncapableContext;
use super::Signature;
#[test]
fn capabilities() {
let none = Secp256k1::with_caps(ContextFlag::None);
let sign = Secp256k1::with_caps(ContextFlag::SignOnly);
let vrfy = Secp256k1::with_caps(ContextFlag::VerifyOnly);
let full = Secp256k1::with_caps(ContextFlag::Full);
let mut msg = [0u8; 32];
thread_rng().fill_bytes(&mut msg);
let msg = Message::from_slice(&msg).unwrap();
let (sk, pk) = full.generate_keypair(&mut thread_rng()).unwrap();
assert_eq!(none.sign_schnorr(&msg, &sk), Err(IncapableContext));
assert_eq!(vrfy.sign_schnorr(&msg, &sk), Err(IncapableContext));
assert!(sign.sign_schnorr(&msg, &sk).is_ok());
assert!(full.sign_schnorr(&msg, &sk).is_ok());
assert_eq!(sign.sign_schnorr(&msg, &sk), full.sign_schnorr(&msg, &sk));
let sig = full.sign_schnorr(&msg, &sk).unwrap();
assert_eq!(none.verify_schnorr(&msg, &sig, &pk), Err(IncapableContext));
assert_eq!(sign.verify_schnorr(&msg, &sig, &pk), Err(IncapableContext));
assert!(vrfy.verify_schnorr(&msg, &sig, &pk).is_ok());
assert!(full.verify_schnorr(&msg, &sig, &pk).is_ok());
assert_eq!(none.recover_schnorr(&msg, &sig), Err(IncapableContext));
assert_eq!(sign.recover_schnorr(&msg, &sig), Err(IncapableContext));
assert!(vrfy.recover_schnorr(&msg, &sig).is_ok());
assert!(full.recover_schnorr(&msg, &sig).is_ok());
assert_eq!(vrfy.recover_schnorr(&msg, &sig),
full.recover_schnorr(&msg, &sig));
assert_eq!(full.recover_schnorr(&msg, &sig), Ok(pk));
}
#[test]
fn sign_verify() {
let mut s = Secp256k1::new();
s.randomize(&mut thread_rng());
let mut msg = [0u8; 32];
thread_rng().fill_bytes(&mut msg);
let msg = Message::from_slice(&msg).unwrap();
let (sk, pk) = s.generate_keypair(&mut thread_rng()).unwrap();
let sig = s.sign_schnorr(&msg, &sk).unwrap();
assert!(s.verify_schnorr(&msg, &sig, &pk).is_ok());
}
#[test]
fn deserialize() {
let mut s = Secp256k1::new();
s.randomize(&mut thread_rng());
let mut msg = [0u8; 32];
thread_rng().fill_bytes(&mut msg);
let msg = Message::from_slice(&msg).unwrap();
let (sk, _) = s.generate_keypair(&mut thread_rng()).unwrap();
let sig1 = s.sign_schnorr(&msg, &sk).unwrap();
let sig2 = Signature::deserialize(&sig1.serialize());
assert_eq!(sig1, sig2);
}
}