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rust-secp256k1-unsafe-fast
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Introduce generic-based capability handling 

Add type parameter to Secp256k1
Add PhantomData for C
Separate into structs and traits
Move constructors to own impl blocks
This commit is contained in:
Thomas Eizinger 2018-06-03 12:35:12 +10:00
parent e3b08c2f5e
commit f1a88259fb
4 changed files with 130 additions and 134 deletions
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2
src/ecdh.rs
View File

@ -29,7 +29,7 @@ pub struct SharedSecret(ffi::SharedSecret);
impl SharedSecret { impl SharedSecret {
/// Creates a new shared secret from a pubkey and secret key /// Creates a new shared secret from a pubkey and secret key
#[inline] #[inline]
pub fn new(secp: &Secp256k1, point: &PublicKey, scalar: &SecretKey) -> SharedSecret { pub fn new<C>(secp: &Secp256k1<C>, point: &PublicKey, scalar: &SecretKey) -> SharedSecret {
unsafe { unsafe {
let mut ss = ffi::SharedSecret::blank(); let mut ss = ffi::SharedSecret::blank();
let res = ffi::secp256k1_ecdh(secp.ctx, &mut ss, point.as_ptr(), scalar.as_ptr()); let res = ffi::secp256k1_ecdh(secp.ctx, &mut ss, point.as_ptr(), scalar.as_ptr());

35
src/key.rs
View File

@ -21,6 +21,8 @@ use std::mem;
use super::{Secp256k1, ContextFlag}; use super::{Secp256k1, ContextFlag};
use super::Error::{self, IncapableContext, InvalidPublicKey, InvalidSecretKey}; use super::Error::{self, IncapableContext, InvalidPublicKey, InvalidSecretKey};
use Signing;
use Verification;
use constants; use constants;
use ffi; use ffi;
@ -63,7 +65,7 @@ impl SecretKey {
/// Creates a new random secret key /// Creates a new random secret key
#[inline] #[inline]
#[cfg(any(test, feature = "rand"))] #[cfg(any(test, feature = "rand"))]
pub fn new<R: Rng>(secp: &Secp256k1, rng: &mut R) -> SecretKey { pub fn new<R: Rng, C>(secp: &Secp256k1<C>, rng: &mut R) -> SecretKey {
let mut data = random_32_bytes(rng); let mut data = random_32_bytes(rng);
unsafe { unsafe {
while ffi::secp256k1_ec_seckey_verify(secp.ctx, data.as_ptr()) == 0 { while ffi::secp256k1_ec_seckey_verify(secp.ctx, data.as_ptr()) == 0 {
@ -75,7 +77,7 @@ impl SecretKey {
/// Converts a `SECRET_KEY_SIZE`-byte slice to a secret key /// Converts a `SECRET_KEY_SIZE`-byte slice to a secret key
#[inline] #[inline]
pub fn from_slice(secp: &Secp256k1, data: &[u8]) pub fn from_slice<C>(secp: &Secp256k1<C>, data: &[u8])
-> Result<SecretKey, Error> { -> Result<SecretKey, Error> {
match data.len() { match data.len() {
constants::SECRET_KEY_SIZE => { constants::SECRET_KEY_SIZE => {
@ -94,7 +96,7 @@ impl SecretKey {
#[inline] #[inline]
/// Adds one secret key to another, modulo the curve order /// Adds one secret key to another, modulo the curve order
pub fn add_assign(&mut self, secp: &Secp256k1, other: &SecretKey) pub fn add_assign<C>(&mut self, secp: &Secp256k1<C>, other: &SecretKey)
-> Result<(), Error> { -> Result<(), Error> {
unsafe { unsafe {
if ffi::secp256k1_ec_privkey_tweak_add(secp.ctx, self.as_mut_ptr(), other.as_ptr()) != 1 { if ffi::secp256k1_ec_privkey_tweak_add(secp.ctx, self.as_mut_ptr(), other.as_ptr()) != 1 {
@ -107,7 +109,7 @@ impl SecretKey {
#[inline] #[inline]
/// Multiplies one secret key by another, modulo the curve order /// Multiplies one secret key by another, modulo the curve order
pub fn mul_assign(&mut self, secp: &Secp256k1, other: &SecretKey) pub fn mul_assign<C>(&mut self, secp: &Secp256k1<C>, other: &SecretKey)
-> Result<(), Error> { -> Result<(), Error> {
unsafe { unsafe {
if ffi::secp256k1_ec_privkey_tweak_mul(secp.ctx, self.as_mut_ptr(), other.as_ptr()) != 1 { if ffi::secp256k1_ec_privkey_tweak_mul(secp.ctx, self.as_mut_ptr(), other.as_ptr()) != 1 {
@ -142,12 +144,9 @@ impl PublicKey {
/// Creates a new public key from a secret key. /// Creates a new public key from a secret key.
#[inline] #[inline]
pub fn from_secret_key(secp: &Secp256k1, pub fn from_secret_key<C: Signing>(secp: &Secp256k1<C>,
sk: &SecretKey) sk: &SecretKey)
-> Result<PublicKey, Error> { -> Result<PublicKey, Error> {
if secp.caps == ContextFlag::VerifyOnly || secp.caps == ContextFlag::None {
return Err(IncapableContext);
}
let mut pk = unsafe { ffi::PublicKey::blank() }; let mut pk = unsafe { ffi::PublicKey::blank() };
unsafe { unsafe {
// We can assume the return value because it's not possible to construct // We can assume the return value because it's not possible to construct
@ -160,7 +159,7 @@ impl PublicKey {
/// Creates a public key directly from a slice /// Creates a public key directly from a slice
#[inline] #[inline]
pub fn from_slice(secp: &Secp256k1, data: &[u8]) pub fn from_slice<C>(secp: &Secp256k1<C>, data: &[u8])
-> Result<PublicKey, Error> { -> Result<PublicKey, Error> {
let mut pk = unsafe { ffi::PublicKey::blank() }; let mut pk = unsafe { ffi::PublicKey::blank() };
@ -179,7 +178,7 @@ impl PublicKey {
/// the y-coordinate is represented by only a single bit, as x determines /// the y-coordinate is represented by only a single bit, as x determines
/// it up to one bit. /// it up to one bit.
pub fn serialize(&self) -> [u8; constants::PUBLIC_KEY_SIZE] { pub fn serialize(&self) -> [u8; constants::PUBLIC_KEY_SIZE] {
let secp = Secp256k1::with_caps(ContextFlag::None); let secp = Secp256k1::without_caps();
let mut ret = [0; constants::PUBLIC_KEY_SIZE]; let mut ret = [0; constants::PUBLIC_KEY_SIZE];
unsafe { unsafe {
@ -199,7 +198,7 @@ impl PublicKey {
/// Serialize the key as a byte-encoded pair of values, in uncompressed form /// Serialize the key as a byte-encoded pair of values, in uncompressed form
pub fn serialize_uncompressed(&self) -> [u8; constants::UNCOMPRESSED_PUBLIC_KEY_SIZE] { pub fn serialize_uncompressed(&self) -> [u8; constants::UNCOMPRESSED_PUBLIC_KEY_SIZE] {
let secp = Secp256k1::with_caps(ContextFlag::None); let secp = Secp256k1::without_caps();
let mut ret = [0; constants::UNCOMPRESSED_PUBLIC_KEY_SIZE]; let mut ret = [0; constants::UNCOMPRESSED_PUBLIC_KEY_SIZE];
unsafe { unsafe {
@ -219,11 +218,8 @@ impl PublicKey {
#[inline] #[inline]
/// Adds the pk corresponding to `other` to the pk `self` in place /// Adds the pk corresponding to `other` to the pk `self` in place
pub fn add_exp_assign(&mut self, secp: &Secp256k1, other: &SecretKey) pub fn add_exp_assign<C: Verification>(&mut self, secp: &Secp256k1<C>, other: &SecretKey)
-> Result<(), Error> { -> Result<(), Error> {
if secp.caps == ContextFlag::SignOnly || secp.caps == ContextFlag::None {
return Err(IncapableContext);
}
unsafe { unsafe {
if ffi::secp256k1_ec_pubkey_tweak_add(secp.ctx, &mut self.0 as *mut _, if ffi::secp256k1_ec_pubkey_tweak_add(secp.ctx, &mut self.0 as *mut _,
other.as_ptr()) == 1 { other.as_ptr()) == 1 {
@ -236,11 +232,8 @@ impl PublicKey {
#[inline] #[inline]
/// Muliplies the pk `self` in place by the scalar `other` /// Muliplies the pk `self` in place by the scalar `other`
pub fn mul_assign(&mut self, secp: &Secp256k1, other: &SecretKey) pub fn mul_assign<C: Verification>(&mut self, secp: &Secp256k1<C>, other: &SecretKey)
-> Result<(), Error> { -> Result<(), Error> {
if secp.caps == ContextFlag::SignOnly || secp.caps == ContextFlag::None {
return Err(IncapableContext);
}
unsafe { unsafe {
if ffi::secp256k1_ec_pubkey_tweak_mul(secp.ctx, &mut self.0 as *mut _, if ffi::secp256k1_ec_pubkey_tweak_mul(secp.ctx, &mut self.0 as *mut _,
other.as_ptr()) == 1 { other.as_ptr()) == 1 {
@ -254,7 +247,7 @@ impl PublicKey {
/// Adds a second key to this one, returning the sum. Returns an error if /// Adds a second key to this one, returning the sum. Returns an error if
/// the result would be the point at infinity, i.e. we are adding this point /// the result would be the point at infinity, i.e. we are adding this point
/// to its own negation /// to its own negation
pub fn combine(&self, secp: &Secp256k1, other: &PublicKey) -> Result<PublicKey, Error> { pub fn combine<C>(&self, secp: &Secp256k1<C>, other: &PublicKey) -> Result<PublicKey, Error> {
unsafe { unsafe {
let mut ret = mem::uninitialized(); let mut ret = mem::uninitialized();
let ptrs = [self.as_ptr(), other.as_ptr()]; let ptrs = [self.as_ptr(), other.as_ptr()];
@ -577,7 +570,7 @@ mod test {
assert!(pk2 <= pk1); assert!(pk2 <= pk1);
assert!(!(pk2 < pk1)); assert!(!(pk2 < pk1));
assert!(!(pk1 < pk2)); assert!(!(pk1 < pk2));
assert!(pk3 < pk1); assert!(pk3 < pk1);
assert!(pk1 > pk3); assert!(pk1 > pk3);
assert!(pk3 <= pk1); assert!(pk3 <= pk1);

175
src/lib.rs
View File

@ -56,6 +56,7 @@ pub mod schnorr;
pub use key::SecretKey; pub use key::SecretKey;
pub use key::PublicKey; pub use key::PublicKey;
use std::marker::PhantomData;
/// A tag used for recovering the public key from a compact signature /// A tag used for recovering the public key from a compact signature
#[derive(Copy, Clone, PartialEq, Eq, Debug)] #[derive(Copy, Clone, PartialEq, Eq, Debug)]
@ -89,7 +90,7 @@ impl RecoveryId {
impl Signature { impl Signature {
#[inline] #[inline]
/// Converts a DER-encoded byte slice to a signature /// Converts a DER-encoded byte slice to a signature
pub fn from_der(secp: &Secp256k1, data: &[u8]) -> Result<Signature, Error> { pub fn from_der<C>(secp: &Secp256k1<C>, data: &[u8]) -> Result<Signature, Error> {
let mut ret = unsafe { ffi::Signature::blank() }; let mut ret = unsafe { ffi::Signature::blank() };
unsafe { unsafe {
@ -103,7 +104,7 @@ impl Signature {
} }
/// Converts a 64-byte compact-encoded byte slice to a signature /// Converts a 64-byte compact-encoded byte slice to a signature
pub fn from_compact(secp: &Secp256k1, data: &[u8]) -> Result<Signature, Error> { pub fn from_compact<C>(secp: &Secp256k1<C>, data: &[u8]) -> Result<Signature, Error> {
let mut ret = unsafe { ffi::Signature::blank() }; let mut ret = unsafe { ffi::Signature::blank() };
if data.len() != 64 { if data.len() != 64 {
return Err(Error::InvalidSignature) return Err(Error::InvalidSignature)
@ -123,7 +124,7 @@ impl Signature {
/// only useful for validating signatures in the Bitcoin blockchain from before /// only useful for validating signatures in the Bitcoin blockchain from before
/// 2016. It should never be used in new applications. This library does not /// 2016. It should never be used in new applications. This library does not
/// support serializing to this "format" /// support serializing to this "format"
pub fn from_der_lax(secp: &Secp256k1, data: &[u8]) -> Result<Signature, Error> { pub fn from_der_lax<C>(secp: &Secp256k1<C>, data: &[u8]) -> Result<Signature, Error> {
unsafe { unsafe {
let mut ret = ffi::Signature::blank(); let mut ret = ffi::Signature::blank();
if ffi::ecdsa_signature_parse_der_lax(secp.ctx, &mut ret, if ffi::ecdsa_signature_parse_der_lax(secp.ctx, &mut ret,
@ -152,7 +153,7 @@ impl Signature {
/// valid. (For example, parsing the historic Bitcoin blockchain requires /// valid. (For example, parsing the historic Bitcoin blockchain requires
/// this.) For these applications we provide this normalization function, /// this.) For these applications we provide this normalization function,
/// which ensures that the s value lies in the lower half of its range. /// which ensures that the s value lies in the lower half of its range.
pub fn normalize_s(&mut self, secp: &Secp256k1) { pub fn normalize_s<C>(&mut self, secp: &Secp256k1<C>) {
unsafe { unsafe {
// Ignore return value, which indicates whether the sig // Ignore return value, which indicates whether the sig
// was already normalized. We don't care. // was already normalized. We don't care.
@ -175,7 +176,7 @@ impl Signature {
#[inline] #[inline]
/// Serializes the signature in DER format /// Serializes the signature in DER format
pub fn serialize_der(&self, secp: &Secp256k1) -> Vec<u8> { pub fn serialize_der<C>(&self, secp: &Secp256k1<C>) -> Vec<u8> {
let mut ret = Vec::with_capacity(72); let mut ret = Vec::with_capacity(72);
let mut len: size_t = ret.capacity() as size_t; let mut len: size_t = ret.capacity() as size_t;
unsafe { unsafe {
@ -189,7 +190,7 @@ impl Signature {
#[inline] #[inline]
/// Serializes the signature in compact format /// Serializes the signature in compact format
pub fn serialize_compact(&self, secp: &Secp256k1) -> [u8; 64] { pub fn serialize_compact<C>(&self, secp: &Secp256k1<C>) -> [u8; 64] {
let mut ret = [0; 64]; let mut ret = [0; 64];
unsafe { unsafe {
let err = ffi::secp256k1_ecdsa_signature_serialize_compact(secp.ctx, ret.as_mut_ptr(), let err = ffi::secp256k1_ecdsa_signature_serialize_compact(secp.ctx, ret.as_mut_ptr(),
@ -214,7 +215,7 @@ impl RecoverableSignature {
/// Converts a compact-encoded byte slice to a signature. This /// Converts a compact-encoded byte slice to a signature. This
/// representation is nonstandard and defined by the libsecp256k1 /// representation is nonstandard and defined by the libsecp256k1
/// library. /// library.
pub fn from_compact(secp: &Secp256k1, data: &[u8], recid: RecoveryId) -> Result<RecoverableSignature, Error> { pub fn from_compact<C>(secp: &Secp256k1<C>, data: &[u8], recid: RecoveryId) -> Result<RecoverableSignature, Error> {
let mut ret = unsafe { ffi::RecoverableSignature::blank() }; let mut ret = unsafe { ffi::RecoverableSignature::blank() };
unsafe { unsafe {
@ -237,7 +238,7 @@ impl RecoverableSignature {
#[inline] #[inline]
/// Serializes the recoverable signature in compact format /// Serializes the recoverable signature in compact format
pub fn serialize_compact(&self, secp: &Secp256k1) -> (RecoveryId, [u8; 64]) { pub fn serialize_compact<C>(&self, secp: &Secp256k1<C>) -> (RecoveryId, [u8; 64]) {
let mut ret = [0u8; 64]; let mut ret = [0u8; 64];
let mut recid = 0i32; let mut recid = 0i32;
unsafe { unsafe {
@ -251,7 +252,7 @@ impl RecoverableSignature {
/// Converts a recoverable signature to a non-recoverable one (this is needed /// Converts a recoverable signature to a non-recoverable one (this is needed
/// for verification /// for verification
#[inline] #[inline]
pub fn to_standard(&self, secp: &Secp256k1) -> Signature { pub fn to_standard<C>(&self, secp: &Secp256k1<C>) -> Signature {
let mut ret = unsafe { ffi::Signature::blank() }; let mut ret = unsafe { ffi::Signature::blank() };
unsafe { unsafe {
let err = ffi::secp256k1_ecdsa_recoverable_signature_convert(secp.ctx, &mut ret, self.as_ptr()); let err = ffi::secp256k1_ecdsa_recoverable_signature_convert(secp.ctx, &mut ret, self.as_ptr());
@ -376,14 +377,28 @@ impl error::Error for Error {
} }
} }
pub trait Signing {}
pub trait Verification {}
pub struct None {}
pub struct SignOnly {}
pub struct VerifyOnly {}
pub struct All {}
impl Signing for SignOnly {}
impl Signing for All {}
impl Verification for VerifyOnly {}
impl Verification for All {}
/// The secp256k1 engine, used to execute all signature operations /// The secp256k1 engine, used to execute all signature operations
pub struct Secp256k1 { pub struct Secp256k1<C> {
ctx: *mut ffi::Context, ctx: *mut ffi::Context,
caps: ContextFlag phantom: PhantomData<C>
} }
unsafe impl Send for Secp256k1 {} unsafe impl<C> Send for Secp256k1<C> {}
unsafe impl Sync for Secp256k1 {} unsafe impl<C> Sync for Secp256k1<C> {}
/// Flags used to determine the capabilities of a `Secp256k1` object; /// Flags used to determine the capabilities of a `Secp256k1` object;
/// the more capabilities, the more expensive it is to create. /// the more capabilities, the more expensive it is to create.
@ -407,54 +422,56 @@ impl fmt::Display for ContextFlag {
} }
} }
impl Clone for Secp256k1 { impl<C> Clone for Secp256k1<C> {
fn clone(&self) -> Secp256k1 { fn clone(&self) -> Secp256k1<C> {
Secp256k1 { Secp256k1 {
ctx: unsafe { ffi::secp256k1_context_clone(self.ctx) }, ctx: unsafe { ffi::secp256k1_context_clone(self.ctx) },
caps: self.caps phantom: self.phantom
} }
} }
} }
impl PartialEq for Secp256k1 { impl<C> PartialEq for Secp256k1<C> {
fn eq(&self, other: &Secp256k1) -> bool { self.caps == other.caps } fn eq(&self, other: &Secp256k1<C>) -> bool { true }
}
impl Eq for Secp256k1 { }
impl fmt::Debug for Secp256k1 {
fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
write!(f, "Secp256k1 {{ [private], caps: {:?} }}", self.caps)
}
} }
impl Drop for Secp256k1 { impl<C> Eq for Secp256k1<C> { }
impl<C> Drop for Secp256k1<C> {
fn drop(&mut self) { fn drop(&mut self) {
unsafe { ffi::secp256k1_context_destroy(self.ctx); } unsafe { ffi::secp256k1_context_destroy(self.ctx); }
} }
} }
impl Secp256k1 { impl Secp256k1<None> {
/// Creates a new Secp256k1 context
#[inline]
pub fn new() -> Secp256k1 {
Secp256k1::with_caps(ContextFlag::Full)
}
/// Creates a new Secp256k1 context with the specified capabilities
pub fn with_caps(caps: ContextFlag) -> Secp256k1 {
let flag = match caps {
ContextFlag::None => ffi::SECP256K1_START_NONE,
ContextFlag::SignOnly => ffi::SECP256K1_START_SIGN,
ContextFlag::VerifyOnly => ffi::SECP256K1_START_VERIFY,
ContextFlag::Full => ffi::SECP256K1_START_SIGN | ffi::SECP256K1_START_VERIFY
};
Secp256k1 { ctx: unsafe { ffi::secp256k1_context_create(flag) }, caps: caps }
}
/// Creates a new Secp256k1 context with no capabilities (just de/serialization) /// Creates a new Secp256k1 context with no capabilities (just de/serialization)
pub fn without_caps() -> Secp256k1 { pub fn without_caps() -> Secp256k1<None> {
Secp256k1::with_caps(ContextFlag::None) Secp256k1 { ctx: unsafe { ffi::secp256k1_context_create(ffi::SECP256K1_START_NONE) }, phantom: PhantomData }
} }
}
impl Secp256k1<All> {
/// Creates a new Secp256k1 context
pub fn new() -> Secp256k1<All> {
Secp256k1 { ctx: unsafe { ffi::secp256k1_context_create(ffi::SECP256K1_START_SIGN | ffi::SECP256K1_START_VERIFY) }, phantom: PhantomData }
}
}
impl Secp256k1<SignOnly> {
pub fn signing_only() -> Secp256k1<SignOnly> {
Secp256k1 { ctx: unsafe { ffi::secp256k1_context_create(ffi::SECP256K1_START_SIGN) }, phantom: PhantomData }
}
}
impl Secp256k1<VerifyOnly> {
pub fn verification_only() -> Secp256k1<VerifyOnly> {
Secp256k1 { ctx: unsafe { ffi::secp256k1_context_create(ffi::SECP256K1_START_VERIFY) }, phantom: PhantomData }
}
}
impl<C> Secp256k1<C> {
/// (Re)randomizes the Secp256k1 context for cheap sidechannel resistence; /// (Re)randomizes the Secp256k1 context for cheap sidechannel resistence;
/// see comment in libsecp256k1 commit d2275795f by Gregory Maxwell /// see comment in libsecp256k1 commit d2275795f by Gregory Maxwell
@ -476,25 +493,14 @@ impl Secp256k1 {
} }
} }
/// Generates a random keypair. Convenience function for `key::SecretKey::new` }
/// and `key::PublicKey::from_secret_key`; call those functions directly for
/// batch key generation. Requires a signing-capable context. impl<C: Signing> Secp256k1<C> {
#[inline]
#[cfg(any(test, feature = "rand"))]
pub fn generate_keypair<R: Rng>(&self, rng: &mut R)
-> Result<(key::SecretKey, key::PublicKey), Error> {
let sk = key::SecretKey::new(self, rng);
let pk = try!(key::PublicKey::from_secret_key(self, &sk));
Ok((sk, pk))
}
/// Constructs a signature for `msg` using the secret key `sk` and RFC6979 nonce /// Constructs a signature for `msg` using the secret key `sk` and RFC6979 nonce
/// Requires a signing-capable context. /// Requires a signing-capable context.
pub fn sign(&self, msg: &Message, sk: &key::SecretKey) pub fn sign(&self, msg: &Message, sk: &key::SecretKey)
-> Result<Signature, Error> { -> Result<Signature, Error> {
if self.caps == ContextFlag::VerifyOnly || self.caps == ContextFlag::None {
return Err(Error::IncapableContext);
}
let mut ret = unsafe { ffi::Signature::blank() }; let mut ret = unsafe { ffi::Signature::blank() };
unsafe { unsafe {
@ -510,10 +516,7 @@ impl Secp256k1 {
/// Constructs a signature for `msg` using the secret key `sk` and RFC6979 nonce /// Constructs a signature for `msg` using the secret key `sk` and RFC6979 nonce
/// Requires a signing-capable context. /// Requires a signing-capable context.
pub fn sign_recoverable(&self, msg: &Message, sk: &key::SecretKey) pub fn sign_recoverable(&self, msg: &Message, sk: &key::SecretKey)
-> Result<RecoverableSignature, Error> { -> Result<RecoverableSignature, Error> {
if self.caps == ContextFlag::VerifyOnly || self.caps == ContextFlag::None {
return Err(Error::IncapableContext);
}
let mut ret = unsafe { ffi::RecoverableSignature::blank() }; let mut ret = unsafe { ffi::RecoverableSignature::blank() };
unsafe { unsafe {
@ -526,13 +529,25 @@ impl Secp256k1 {
Ok(RecoverableSignature::from(ret)) Ok(RecoverableSignature::from(ret))
} }
/// Generates a random keypair. Convenience function for `key::SecretKey::new`
/// and `key::PublicKey::from_secret_key`; call those functions directly for
/// batch key generation. Requires a signing-capable context.
#[inline]
#[cfg(any(test, feature = "rand"))]
pub fn generate_keypair<R: Rng>(&self, rng: &mut R)
-> Result<(key::SecretKey, key::PublicKey), Error> {
let sk = key::SecretKey::new(self, rng);
let pk = try!(key::PublicKey::from_secret_key(self, &sk));
Ok((sk, pk))
}
}
impl<C: Verification> Secp256k1<C> {
/// Determines the public key for which `sig` is a valid signature for /// Determines the public key for which `sig` is a valid signature for
/// `msg`. Requires a verify-capable context. /// `msg`. Requires a verify-capable context.
pub fn recover(&self, msg: &Message, sig: &RecoverableSignature) pub fn recover(&self, msg: &Message, sig: &RecoverableSignature)
-> Result<key::PublicKey, Error> { -> Result<key::PublicKey, Error> {
if self.caps == ContextFlag::SignOnly || self.caps == ContextFlag::None {
return Err(Error::IncapableContext);
}
let mut pk = unsafe { ffi::PublicKey::blank() }; let mut pk = unsafe { ffi::PublicKey::blank() };
@ -552,9 +567,6 @@ impl Secp256k1 {
/// verify-capable context. /// verify-capable context.
#[inline] #[inline]
pub fn verify(&self, msg: &Message, sig: &Signature, pk: &key::PublicKey) -> Result<(), Error> { pub fn verify(&self, msg: &Message, sig: &Signature, pk: &key::PublicKey) -> Result<(), Error> {
if self.caps == ContextFlag::SignOnly || self.caps == ContextFlag::None {
return Err(Error::IncapableContext);
}
if !pk.is_valid() { if !pk.is_valid() {
Err(Error::InvalidPublicKey) Err(Error::InvalidPublicKey)
@ -567,14 +579,13 @@ impl Secp256k1 {
} }
} }
#[cfg(test)] #[cfg(test)]
mod tests { mod tests {
use rand::{Rng, thread_rng}; use rand::{Rng, thread_rng};
use key::{SecretKey, PublicKey}; use key::{SecretKey, PublicKey};
use super::constants; use super::constants;
use super::{Secp256k1, Signature, RecoverableSignature, Message, RecoveryId, ContextFlag}; use super::{Secp256k1, Signature, RecoverableSignature, Message, RecoveryId};
use super::Error::{InvalidMessage, InvalidPublicKey, IncorrectSignature, InvalidSignature, use super::Error::{InvalidMessage, InvalidPublicKey, IncorrectSignature, InvalidSignature,
IncapableContext}; IncapableContext};
@ -603,29 +614,23 @@ mod tests {
#[test] #[test]
fn capabilities() { fn capabilities() {
let none = Secp256k1::with_caps(ContextFlag::None); let none = Secp256k1::without_caps();
let sign = Secp256k1::with_caps(ContextFlag::SignOnly); let sign = Secp256k1::signing_only();
let vrfy = Secp256k1::with_caps(ContextFlag::VerifyOnly); let vrfy = Secp256k1::verification_only();
let full = Secp256k1::with_caps(ContextFlag::Full); let full = Secp256k1::new();
let mut msg = [0u8; 32]; let mut msg = [0u8; 32];
thread_rng().fill_bytes(&mut msg); thread_rng().fill_bytes(&mut msg);
let msg = Message::from_slice(&msg).unwrap(); let msg = Message::from_slice(&msg).unwrap();
// Try key generation // Try key generation
assert_eq!(none.generate_keypair(&mut thread_rng()), Err(IncapableContext));
assert_eq!(vrfy.generate_keypair(&mut thread_rng()), Err(IncapableContext));
assert!(sign.generate_keypair(&mut thread_rng()).is_ok()); assert!(sign.generate_keypair(&mut thread_rng()).is_ok());
assert!(full.generate_keypair(&mut thread_rng()).is_ok()); assert!(full.generate_keypair(&mut thread_rng()).is_ok());
let (sk, pk) = full.generate_keypair(&mut thread_rng()).unwrap(); let (sk, pk) = full.generate_keypair(&mut thread_rng()).unwrap();
// Try signing // Try signing
assert_eq!(none.sign(&msg, &sk), Err(IncapableContext));
assert_eq!(vrfy.sign(&msg, &sk), Err(IncapableContext));
assert!(sign.sign(&msg, &sk).is_ok()); assert!(sign.sign(&msg, &sk).is_ok());
assert!(full.sign(&msg, &sk).is_ok()); assert!(full.sign(&msg, &sk).is_ok());
assert_eq!(none.sign_recoverable(&msg, &sk), Err(IncapableContext));
assert_eq!(vrfy.sign_recoverable(&msg, &sk), Err(IncapableContext));
assert!(sign.sign_recoverable(&msg, &sk).is_ok()); assert!(sign.sign_recoverable(&msg, &sk).is_ok());
assert!(full.sign_recoverable(&msg, &sk).is_ok()); assert!(full.sign_recoverable(&msg, &sk).is_ok());
assert_eq!(sign.sign(&msg, &sk), full.sign(&msg, &sk)); assert_eq!(sign.sign(&msg, &sk), full.sign(&msg, &sk));
@ -634,14 +639,10 @@ mod tests {
let sigr = full.sign_recoverable(&msg, &sk).unwrap(); let sigr = full.sign_recoverable(&msg, &sk).unwrap();
// Try verifying // Try verifying
assert_eq!(none.verify(&msg, &sig, &pk), Err(IncapableContext));
assert_eq!(sign.verify(&msg, &sig, &pk), Err(IncapableContext));
assert!(vrfy.verify(&msg, &sig, &pk).is_ok()); assert!(vrfy.verify(&msg, &sig, &pk).is_ok());
assert!(full.verify(&msg, &sig, &pk).is_ok()); assert!(full.verify(&msg, &sig, &pk).is_ok());
// Try pk recovery // Try pk recovery
assert_eq!(none.recover(&msg, &sigr), Err(IncapableContext));
assert_eq!(sign.recover(&msg, &sigr), Err(IncapableContext));
assert!(vrfy.recover(&msg, &sigr).is_ok()); assert!(vrfy.recover(&msg, &sigr).is_ok());
assert!(full.recover(&msg, &sigr).is_ok()); assert!(full.recover(&msg, &sigr).is_ok());

52
src/schnorr.rs
View File

@ -19,13 +19,15 @@ use ContextFlag;
use Error; use Error;
use Message; use Message;
use Secp256k1; use Secp256k1;
use Signing;
use constants; use constants;
use ffi; use ffi;
use key::{SecretKey, PublicKey}; use key::{PublicKey, SecretKey};
use std::{mem, ptr}; use Verification;
use std::convert::From; use std::convert::From;
use std::{mem, ptr};
/// A Schnorr signature. /// A Schnorr signature.
pub struct Signature([u8; constants::SCHNORR_SIGNATURE_SIZE]); pub struct Signature([u8; constants::SCHNORR_SIGNATURE_SIZE]);
@ -47,35 +49,41 @@ impl Signature {
} }
} }
impl Secp256k1 { impl<C: Signing> Secp256k1<C> {
/// Create a Schnorr signature /// Create a Schnorr signature
pub fn sign_schnorr(&self, msg: &Message, sk: &SecretKey) -> Result<Signature, Error> { 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() }; let mut ret: Signature = unsafe { mem::uninitialized() };
unsafe { unsafe {
// We can assume the return value because it's not possible to construct // We can assume the return value because it's not possible to construct
// an invalid signature from a valid `Message` and `SecretKey` // an invalid signature from a valid `Message` and `SecretKey`
let err = ffi::secp256k1_schnorr_sign(self.ctx, ret.as_mut_ptr(), msg.as_ptr(), let err = ffi::secp256k1_schnorr_sign(
sk.as_ptr(), ffi::secp256k1_nonce_function_rfc6979, self.ctx,
ptr::null()); ret.as_mut_ptr(),
msg.as_ptr(),
sk.as_ptr(),
ffi::secp256k1_nonce_function_rfc6979,
ptr::null(),
);
debug_assert_eq!(err, 1); debug_assert_eq!(err, 1);
} }
Ok(ret) Ok(ret)
} }
}
impl<C: Verification> Secp256k1<C> {
/// Verify a Schnorr signature /// Verify a Schnorr signature
pub fn verify_schnorr(&self, msg: &Message, sig: &Signature, pk: &PublicKey) -> Result<(), Error> { pub fn verify_schnorr(
if self.caps == ContextFlag::SignOnly || self.caps == ContextFlag::None { &self,
return Err(Error::IncapableContext); msg: &Message,
} sig: &Signature,
pk: &PublicKey,
) -> Result<(), Error> {
if !pk.is_valid() { if !pk.is_valid() {
Err(Error::InvalidPublicKey) Err(Error::InvalidPublicKey)
} else if unsafe { ffi::secp256k1_schnorr_verify(self.ctx, sig.as_ptr(), msg.as_ptr(), } else if unsafe {
pk.as_ptr()) } == 0 { ffi::secp256k1_schnorr_verify(self.ctx, sig.as_ptr(), msg.as_ptr(), pk.as_ptr())
} == 0
{
Err(Error::IncorrectSignature) Err(Error::IncorrectSignature)
} else { } else {
Ok(()) Ok(())
@ -84,16 +92,10 @@ impl Secp256k1 {
/// Retrieves the public key for which `sig` is a valid signature for `msg`. /// Retrieves the public key for which `sig` is a valid signature for `msg`.
/// Requires a verify-capable context. /// Requires a verify-capable context.
pub fn recover_schnorr(&self, msg: &Message, sig: &Signature) pub fn recover_schnorr(&self, msg: &Message, sig: &Signature) -> Result<PublicKey, Error> {
-> Result<PublicKey, Error> {
if self.caps == ContextFlag::SignOnly || self.caps == ContextFlag::None {
return Err(Error::IncapableContext);
}
let mut pk = unsafe { ffi::PublicKey::blank() }; let mut pk = unsafe { ffi::PublicKey::blank() };
unsafe { unsafe {
if ffi::secp256k1_schnorr_recover(self.ctx, &mut pk, if ffi::secp256k1_schnorr_recover(self.ctx, &mut pk, sig.as_ptr(), msg.as_ptr()) != 1 {
sig.as_ptr(), msg.as_ptr()) != 1 {
return Err(Error::InvalidSignature); return Err(Error::InvalidSignature);
} }
}; };