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Merge remote-tracking branch 'hdevalence/verify-result' into develop

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This commit is contained in:
Isis Lovecruft 2018-07-15 21:21:14 +00:00
commit 3840cb9733
Failed to extract signature
5 changed files with 86 additions and 153 deletions
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8
Cargo.toml
View file

@ -19,10 +19,6 @@ travis-ci = { repository = "dalek-cryptography/ed25519-dalek", branch = "master"
version = "0.18"
default-features = false
[dependencies.subtle]
version = "0.6"
default-features = false
[dependencies.rand]
version = "0.5"
default-features = false
@ -59,8 +55,8 @@ harness = false
[features]
default = ["std", "u64_backend"]
# We don't add "rand/std" here because it would enable a bunch of Fuchsia dependencies.
std = ["subtle/std", "curve25519-dalek/std"]
nightly = ["curve25519-dalek/nightly", "subtle/nightly", "rand/nightly"]
std = ["curve25519-dalek/std"]
nightly = ["curve25519-dalek/nightly", "rand/nightly"]
asm = ["sha2/asm"]
yolocrypto = ["curve25519-dalek/yolocrypto"]
u64_backend = ["curve25519-dalek/u64_backend"]

9
README.md
View file

@ -55,12 +55,9 @@ nanoseconds to cycles per second on a 2591 Mhz CPU, that's 237660 cycles for
verification and 102523 for signing, which for signing is competitive
with optimised assembly versions.
Additionally, if you're on the Rust nightly channel, be sure to build with
`cargo build --features="nightly"` which enables more secure compiler
optimisation protections in the
[subtle](https://github.com/dalek-cryptography/subtle) crate. Additionally, if
you're using a CSPRNG from the `rand` crate, the `nightly` feature will enable
`u128`/`i128` features there, resulting in potentially faster performance.
Additionally, if you're using a CSPRNG from the `rand` crate, the `nightly`
feature will enable `u128`/`i128` features there, resulting in potentially
faster performance.
Additionally, thanks to Rust, this implementation has both type and memory
safety. It's also easily readable by a much larger set of people than those who

172
src/ed25519.rs
View file

@ -36,9 +36,7 @@ use curve25519_dalek::edwards::CompressedEdwardsY;
use curve25519_dalek::edwards::EdwardsPoint;
use curve25519_dalek::scalar::Scalar;
use subtle::ConstantTimeEq;
use errors::DecodingError;
use errors::SignatureError;
use errors::InternalError;
/// The length of a curve25519 EdDSA `Signature`, in bytes.
@ -132,9 +130,9 @@ impl Signature {
/// Construct a `Signature` from a slice of bytes.
#[inline]
pub fn from_bytes(bytes: &[u8]) -> Result<Signature, DecodingError> {
pub fn from_bytes(bytes: &[u8]) -> Result<Signature, SignatureError> {
if bytes.len() != SIGNATURE_LENGTH {
return Err(DecodingError(InternalError::BytesLengthError{
return Err(SignatureError(InternalError::BytesLengthError{
name: "Signature", length: SIGNATURE_LENGTH }));
}
let mut lower: [u8; 32] = [0u8; 32];
@ -144,7 +142,7 @@ impl Signature {
upper.copy_from_slice(&bytes[32..]);
if upper[31] & 224 != 0 {
return Err(DecodingError(InternalError::ScalarFormatError));
return Err(SignatureError(InternalError::ScalarFormatError));
}
Ok(Signature{ r: CompressedEdwardsY(lower), s: Scalar::from_bits(upper) })
@ -215,9 +213,9 @@ impl SecretKey {
/// #
/// use ed25519_dalek::SecretKey;
/// use ed25519_dalek::SECRET_KEY_LENGTH;
/// use ed25519_dalek::DecodingError;
/// use ed25519_dalek::SignatureError;
///
/// # fn doctest() -> Result<SecretKey, DecodingError> {
/// # fn doctest() -> Result<SecretKey, SignatureError> {
/// let secret_key_bytes: [u8; SECRET_KEY_LENGTH] = [
/// 157, 097, 177, 157, 239, 253, 090, 096,
/// 186, 132, 074, 244, 146, 236, 044, 196,
@ -238,11 +236,11 @@ impl SecretKey {
/// # Returns
///
/// A `Result` whose okay value is an EdDSA `SecretKey` or whose error value
/// is an `DecodingError` wrapping the internal error that occurred.
/// is an `SignatureError` wrapping the internal error that occurred.
#[inline]
pub fn from_bytes(bytes: &[u8]) -> Result<SecretKey, DecodingError> {
pub fn from_bytes(bytes: &[u8]) -> Result<SecretKey, SignatureError> {
if bytes.len() != SECRET_KEY_LENGTH {
return Err(DecodingError(InternalError::BytesLengthError{
return Err(SignatureError(InternalError::BytesLengthError{
name: "SecretKey", length: SECRET_KEY_LENGTH }));
}
let mut bits: [u8; 32] = [0u8; 32];
@ -469,7 +467,7 @@ impl ExpandedSecretKey {
/// # Returns
///
/// A `Result` whose okay value is an EdDSA `ExpandedSecretKey` or whose
/// error value is an `DecodingError` describing the error that occurred.
/// error value is an `SignatureError` describing the error that occurred.
///
/// # Examples
///
@ -479,11 +477,11 @@ impl ExpandedSecretKey {
/// # extern crate ed25519_dalek;
/// #
/// # #[cfg(all(feature = "sha2", feature = "std"))]
/// # fn do_test() -> Result<ExpandedSecretKey, DecodingError> {
/// # fn do_test() -> Result<ExpandedSecretKey, SignatureError> {
/// #
/// use rand::{Rng, OsRng};
/// use ed25519_dalek::{SecretKey, ExpandedSecretKey};
/// use ed25519_dalek::DecodingError;
/// use ed25519_dalek::SignatureError;
///
/// let mut csprng: OsRng = OsRng::new().unwrap();
/// let secret_key: SecretKey = SecretKey::generate(&mut csprng);
@ -504,9 +502,9 @@ impl ExpandedSecretKey {
/// # fn main() { }
/// ```
#[inline]
pub fn from_bytes(bytes: &[u8]) -> Result<ExpandedSecretKey, DecodingError> {
pub fn from_bytes(bytes: &[u8]) -> Result<ExpandedSecretKey, SignatureError> {
if bytes.len() != EXPANDED_SECRET_KEY_LENGTH {
return Err(DecodingError(InternalError::BytesLengthError{
return Err(SignatureError(InternalError::BytesLengthError{
name: "ExpandedSecretKey", length: EXPANDED_SECRET_KEY_LENGTH }));
}
let mut lower: [u8; 32] = [0u8; 32];
@ -746,9 +744,9 @@ impl PublicKey {
/// #
/// use ed25519_dalek::PublicKey;
/// use ed25519_dalek::PUBLIC_KEY_LENGTH;
/// use ed25519_dalek::DecodingError;
/// use ed25519_dalek::SignatureError;
///
/// # fn doctest() -> Result<PublicKey, DecodingError> {
/// # fn doctest() -> Result<PublicKey, SignatureError> {
/// let public_key_bytes: [u8; PUBLIC_KEY_LENGTH] = [
/// 215, 90, 152, 1, 130, 177, 10, 183, 213, 75, 254, 211, 201, 100, 7, 58,
/// 14, 225, 114, 243, 218, 166, 35, 37, 175, 2, 26, 104, 247, 7, 81, 26];
@ -766,11 +764,11 @@ impl PublicKey {
/// # Returns
///
/// A `Result` whose okay value is an EdDSA `PublicKey` or whose error value
/// is an `DecodingError` describing the error that occurred.
/// is an `SignatureError` describing the error that occurred.
#[inline]
pub fn from_bytes(bytes: &[u8]) -> Result<PublicKey, DecodingError> {
pub fn from_bytes(bytes: &[u8]) -> Result<PublicKey, SignatureError> {
if bytes.len() != PUBLIC_KEY_LENGTH {
return Err(DecodingError(InternalError::BytesLengthError{
return Err(SignatureError(InternalError::BytesLengthError{
name: "PublicKey", length: PUBLIC_KEY_LENGTH }));
}
let mut bits: [u8; 32] = [0u8; 32];
@ -779,12 +777,6 @@ impl PublicKey {
Ok(PublicKey(CompressedEdwardsY(bits)))
}
/// Convert this public key to its underlying extended twisted Edwards coordinate.
#[inline]
fn decompress(&self) -> Option<EdwardsPoint> {
self.0.decompress()
}
/// Derive this public key from its corresponding `SecretKey`.
#[allow(unused_assignments)]
pub fn from_secret<D>(secret_key: &SecretKey) -> PublicKey
@ -812,36 +804,27 @@ impl PublicKey {
///
/// # Return
///
/// Returns true if the signature was successfully verified, and
/// false otherwise.
pub fn verify<D>(&self, message: &[u8], signature: &Signature) -> bool
/// Returns `Ok(())` if the signature is valid, and `Err` otherwise.
#[allow(non_snake_case)]
pub fn verify<D>(&self, message: &[u8], signature: &Signature) -> Result<(), SignatureError>
where D: Digest<OutputSize = U64> + Default
{
let mut h: D = D::default();
let mut a: EdwardsPoint;
let ao: Option<EdwardsPoint>;
let mut digest: [u8; 64] = [0u8; 64];
ao = self.decompress();
if ao.is_some() {
a = ao.unwrap();
} else {
return false;
}
a = -(&a);
let A = self.0.decompress()
.ok_or_else(|| SignatureError(InternalError::PointDecompressionError))?;
let mut h = D::default();
h.input(signature.r.as_bytes());
h.input(self.as_bytes());
h.input(&message);
let k = Scalar::from_hash(h);
digest.copy_from_slice(h.fixed_result().as_slice());
let R = EdwardsPoint::vartime_double_scalar_mul_basepoint(&k, &(-A), &signature.s);
let digest_reduced: Scalar = Scalar::from_bytes_mod_order_wide(&digest);
let r: EdwardsPoint = EdwardsPoint::vartime_double_scalar_mul_basepoint(&digest_reduced,
&a, &signature.s);
(signature.r.as_bytes()).ct_eq(r.compress().as_bytes()).unwrap_u8() == 1
if R.compress() == signature.r {
Ok(())
} else {
Err(SignatureError(InternalError::VerifyError))
}
}
/// Verify a `signature` on a `prehashed_message` using the Ed25519ph algorithm.
@ -862,43 +845,36 @@ impl PublicKey {
/// `Keypair` on the `prehashed_message`.
///
/// [rfc8032]: https://tools.ietf.org/html/rfc8032#section-5.1
#[allow(non_snake_case)]
pub fn verify_prehashed<D>(&self,
prehashed_message: D,
context: Option<&[u8]>,
signature: &Signature) -> bool
signature: &Signature) -> Result<(), SignatureError>
where D: Digest<OutputSize = U64> + Default
{
let mut h: D = D::default();
let mut hash: [u8; 64] = [0u8; 64];
let mut a: EdwardsPoint = match self.decompress() {
Some(x) => x,
None => return false,
};
a = -(&a);
let ctx: &[u8] = match context {
Some(x) => x,
None => b"", // By default, the context is an empty string.
};
let ctx = context.unwrap_or(b"");
debug_assert!(ctx.len() <= 255, "The context must not be longer than 255 octets.");
let ctx_len: u8 = ctx.len() as u8;
let A = self.0.decompress()
.ok_or_else(|| SignatureError(InternalError::PointDecompressionError))?;
let mut h = D::default();
h.input(b"SigEd25519 no Ed25519 collisions");
h.input(&[1]); // Ed25519ph
h.input(&[ctx_len]);
h.input(&[ctx.len() as u8]);
h.input(ctx);
h.input(signature.r.as_bytes());
h.input(self.as_bytes());
h.input(prehashed_message.fixed_result().as_slice());
hash.copy_from_slice(h.fixed_result().as_slice());
let k = Scalar::from_hash(h);
let digest_reduced: Scalar = Scalar::from_bytes_mod_order_wide(&hash);
let r: EdwardsPoint = EdwardsPoint::vartime_double_scalar_mul_basepoint(&digest_reduced,
&a, &signature.s);
let R = EdwardsPoint::vartime_double_scalar_mul_basepoint(&k, &(-A), &signature.s);
(signature.r.as_bytes()).ct_eq(r.compress().as_bytes()).unwrap_u8() == 1
if R.compress() == signature.r {
Ok(())
} else {
Err(SignatureError(InternalError::VerifyError))
}
}
}
@ -976,10 +952,10 @@ impl Keypair {
/// # Returns
///
/// A `Result` whose okay value is an EdDSA `Keypair` or whose error value
/// is an `DecodingError` describing the error that occurred.
pub fn from_bytes<'a>(bytes: &'a [u8]) -> Result<Keypair, DecodingError> {
/// is an `SignatureError` describing the error that occurred.
pub fn from_bytes<'a>(bytes: &'a [u8]) -> Result<Keypair, SignatureError> {
if bytes.len() != KEYPAIR_LENGTH {
return Err(DecodingError(InternalError::BytesLengthError{
return Err(SignatureError(InternalError::BytesLengthError{
name: "Keypair", length: KEYPAIR_LENGTH}));
}
let secret = SecretKey::from_bytes(&bytes[..SECRET_KEY_LENGTH])?;
@ -1145,7 +1121,7 @@ impl Keypair {
}
/// Verify a signature on a message with this keypair's public key.
pub fn verify<D>(&self, message: &[u8], signature: &Signature) -> bool
pub fn verify<D>(&self, message: &[u8], signature: &Signature) -> Result<(), SignatureError>
where D: Digest<OutputSize = U64> + Default {
self.public.verify::<D>(message, signature)
}
@ -1210,7 +1186,7 @@ impl Keypair {
pub fn verify_prehashed<D>(&self,
prehashed_message: D,
context: Option<&[u8]>,
signature: &Signature) -> bool
signature: &Signature) -> Result<(), SignatureError>
where D: Digest<OutputSize = U64> + Default
{
self.public.verify_prehashed::<D>(prehashed_message, context, signature)
@ -1261,7 +1237,6 @@ mod test {
use std::fs::File;
use std::string::String;
use std::vec::Vec;
use curve25519_dalek::edwards::EdwardsPoint;
use rand::ChaChaRng;
use rand::SeedableRng;
use hex::FromHex;
@ -1295,32 +1270,7 @@ mod test {
063, 120, 126, 100, 092, 059, 050, 011, ];
#[test]
fn unmarshal_marshal() { // TestUnmarshalMarshal
let mut csprng: ChaChaRng;
let mut keypair: Keypair;
let mut x: Option<EdwardsPoint>;
let a: EdwardsPoint;
let public: PublicKey;
csprng = ChaChaRng::from_seed([0u8; 32]);
// from_bytes() fails if vx²-u=0 and vx²+u=0
loop {
keypair = Keypair::generate::<Sha512, _>(&mut csprng);
x = keypair.public.decompress();
if x.is_some() {
a = x.unwrap();
break;
}
}
public = PublicKey(a.compress());
assert!(keypair.public.0 == public.0);
}
#[test]
fn ed25519_sign_verify() { // TestSignVerify
fn sign_verify() { // TestSignVerify
let mut csprng: ChaChaRng;
let keypair: Keypair;
let good_sig: Signature;
@ -1334,11 +1284,11 @@ mod test {
good_sig = keypair.sign::<Sha512>(&good);
bad_sig = keypair.sign::<Sha512>(&bad);
assert!(keypair.verify::<Sha512>(&good, &good_sig) == true,
assert!(keypair.verify::<Sha512>(&good, &good_sig).is_ok(),
"Verification of a valid signature failed!");
assert!(keypair.verify::<Sha512>(&good, &bad_sig) == false,
assert!(keypair.verify::<Sha512>(&good, &bad_sig).is_err(),
"Verification of a signature on a different message passed!");
assert!(keypair.verify::<Sha512>(&bad, &good_sig) == false,
assert!(keypair.verify::<Sha512>(&bad, &good_sig).is_err(),
"Verification of a signature on a different message passed!");
}
@ -1383,7 +1333,7 @@ mod test {
let sig2: Signature = keypair.sign::<Sha512>(&msg_bytes);
assert!(sig1 == sig2, "Signature bytes not equal on line {}", lineno);
assert!(keypair.verify::<Sha512>(&msg_bytes, &sig2),
assert!(keypair.verify::<Sha512>(&msg_bytes, &sig2).is_ok(),
"Signature verification failed on line {}", lineno);
}
}
@ -1417,7 +1367,7 @@ mod test {
assert!(sig1 == sig2,
"Original signature from test vectors doesn't equal signature produced:\
\noriginal:\n{:?}\nproduced:\n{:?}", sig1, sig2);
assert!(keypair.verify_prehashed(prehash_for_verifying, None, &sig2),
assert!(keypair.verify_prehashed(prehash_for_verifying, None, &sig2).is_ok(),
"Could not verify ed25519ph signature!");
}
@ -1451,18 +1401,18 @@ mod test {
good_sig = keypair.sign_prehashed::<Sha512>(prehashed_good1, Some(context));
bad_sig = keypair.sign_prehashed::<Sha512>(prehashed_bad1, Some(context));
assert!(keypair.verify_prehashed::<Sha512>(prehashed_good2, Some(context), &good_sig) == true,
assert!(keypair.verify_prehashed::<Sha512>(prehashed_good2, Some(context), &good_sig).is_ok(),
"Verification of a valid signature failed!");
assert!(keypair.verify_prehashed::<Sha512>(prehashed_good3, Some(context), &bad_sig) == false,
assert!(keypair.verify_prehashed::<Sha512>(prehashed_good3, Some(context), &bad_sig).is_err(),
"Verification of a signature on a different message passed!");
assert!(keypair.verify_prehashed::<Sha512>(prehashed_bad2, Some(context), &good_sig) == false,
assert!(keypair.verify_prehashed::<Sha512>(prehashed_bad2, Some(context), &good_sig).is_err(),
"Verification of a signature on a different message passed!");
}
#[test]
fn public_key_from_bytes() {
// Make another function so that we can test the ? operator.
fn do_the_test() -> Result<PublicKey, DecodingError> {
fn do_the_test() -> Result<PublicKey, SignatureError> {
let public_key_bytes: [u8; PUBLIC_KEY_LENGTH] = [
215, 090, 152, 001, 130, 177, 010, 183,
213, 075, 254, 211, 201, 100, 007, 058,

36
src/errors.rs
View file

@ -20,7 +20,6 @@ use core::fmt::Display;
/// need to pay any attention to these.
#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
pub (crate) enum InternalError {
#[allow(dead_code)]
PointDecompressionError,
ScalarFormatError,
/// An error in the length of bytes handed to a constructor.
@ -29,55 +28,52 @@ pub (crate) enum InternalError {
/// returning the error, and the `length` in bytes which its constructor
/// expects.
BytesLengthError{ name: &'static str, length: usize },
/// The verification equation wasn't satisfied
VerifyError,
}
impl Display for InternalError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match *self {
InternalError::PointDecompressionError
=> write!(f, "Cannot decompress extended twisted edwards point"),
=> write!(f, "Cannot decompress Edwards point"),
InternalError::ScalarFormatError
=> write!(f, "Cannot use scalar with high-bit set"),
InternalError::BytesLengthError{ name: n, length: l}
=> write!(f, "{} must be {} bytes in length", n, l),
InternalError::VerifyError
=> write!(f, "Verification equation was not satisfied"),
}
}
}
impl ::failure::Fail for InternalError {}
/// Errors which may occur in the `from_bytes()` constructors of `PublicKey`,
/// `SecretKey`, `ExpandedSecretKey`, `Keypair`, and `Signature`.
///
/// There was an internal problem due to parsing the `Signature`.
/// Errors which may occur while processing signatures and keypairs.
///
/// This error may arise due to:
///
/// * Being given bytes with a length different to what was expected.
///
/// * A problem decompressing `r`, a curve point, in the `Signature`, or the
/// curve point for a `PublicKey`.
///
/// * A problem with the format of `s`, a scalar, in the `Signature`. This
/// is only raised if the high-bit of the scalar was set. (Scalars must
/// only be constructed from 255-bit integers.)
/// * Being given bytes with a length different to what was expected.
///
/// * Failure of a signature to satisfy the verification equation.
#[derive(Clone, Copy, Eq, PartialEq, Hash, Debug)]
pub struct DecodingError(pub (crate) InternalError);
pub struct SignatureError(pub (crate) InternalError);
impl Display for DecodingError {
impl Display for SignatureError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match self.0 {
InternalError::PointDecompressionError => write!(f, "{}", self.0),
InternalError::ScalarFormatError => write!(f, "{}", self.0),
InternalError::BytesLengthError{ name: _, length: _ } => write!(f, "{}", self.0),
}
write!(f, "{}", self.0)
}
}
impl ::failure::Fail for DecodingError {
impl ::failure::Fail for SignatureError {
fn cause(&self) -> Option<&::failure::Fail> {
match self.0 {
InternalError::PointDecompressionError => Some(&self.0),
InternalError::ScalarFormatError => Some(&self.0),
InternalError::BytesLengthError{ name: _, length: _} => Some(&self.0),
}
Some(&self.0)
}
}

14
src/lib.rs
View file

@ -78,9 +78,7 @@
//! # let keypair: Keypair = Keypair::generate::<Sha512, _>(&mut csprng);
//! # let message: &[u8] = "This is a test of the tsunami alert system.".as_bytes();
//! # let signature: Signature = keypair.sign::<Sha512>(message);
//! let verified: bool = keypair.verify::<Sha512>(message, &signature);
//!
//! assert!(verified);
//! assert!(keypair.verify::<Sha512>(message, &signature).is_ok());
//! # }
//! ```
//!
@ -105,9 +103,7 @@
//! # let signature: Signature = keypair.sign::<Sha512>(message);
//!
//! let public_key: PublicKey = keypair.public;
//! let verified: bool = public_key.verify::<Sha512>(message, &signature);
//!
//! assert!(verified);
//! assert!(public_key.verify::<Sha512>(message, &signature).is_ok());
//! # }
//! ```
//!
@ -133,7 +129,6 @@
//! # let message: &[u8] = "This is a test of the tsunami alert system.".as_bytes();
//! # let signature: Signature = keypair.sign::<Sha512>(message);
//! # let public_key: PublicKey = keypair.public;
//! # let verified: bool = public_key.verify::<Sha512>(message, &signature);
//!
//! let public_key_bytes: [u8; PUBLIC_KEY_LENGTH] = public_key.to_bytes();
//! let secret_key_bytes: [u8; SECRET_KEY_LENGTH] = keypair.secret.to_bytes();
@ -150,9 +145,9 @@
//! # extern crate ed25519_dalek;
//! # use rand::{Rng, ChaChaRng, SeedableRng};
//! # use sha2::Sha512;
//! # use ed25519_dalek::{Keypair, Signature, PublicKey, SecretKey, DecodingError};
//! # use ed25519_dalek::{Keypair, Signature, PublicKey, SecretKey, SignatureError};
//! # use ed25519_dalek::{PUBLIC_KEY_LENGTH, SECRET_KEY_LENGTH, KEYPAIR_LENGTH, SIGNATURE_LENGTH};
//! # fn do_test() -> Result<(SecretKey, PublicKey, Keypair, Signature), DecodingError> {
//! # fn do_test() -> Result<(SecretKey, PublicKey, Keypair, Signature), SignatureError> {
//! # let mut csprng: ChaChaRng = ChaChaRng::from_seed([0u8; 32]);
//! # let keypair_orig: Keypair = Keypair::generate::<Sha512, _>(&mut csprng);
//! # let message: &[u8] = "This is a test of the tsunami alert system.".as_bytes();
@ -267,7 +262,6 @@
extern crate curve25519_dalek;
extern crate generic_array;
extern crate digest;
extern crate subtle;
extern crate failure;
extern crate rand;