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// -*- mode: rust; -*- // // This file is part of ed25519-dalek. // Copyright (c) 2017-2018 Isis Lovecruft // See LICENSE for licensing information. // // Authors: // - Isis Agora Lovecruft <isis@patternsinthevoid.net> //! A Rust implementation of ed25519 EdDSA key generation, signing, and //! verification. use core::default::Default; use core::fmt::{Debug}; use rand::CryptoRng; use rand::Rng; #[cfg(feature = "serde")] use serde::{Serialize, Deserialize}; #[cfg(feature = "serde")] use serde::{Serializer, Deserializer}; #[cfg(feature = "serde")] use serde::de::Error as SerdeError; #[cfg(feature = "serde")] use serde::de::Visitor; #[cfg(feature = "sha2")] use sha2::Sha512; use clear_on_drop::clear::Clear; use curve25519_dalek::digest::Digest; use curve25519_dalek::digest::generic_array::typenum::U64; use curve25519_dalek::constants; use curve25519_dalek::edwards::CompressedEdwardsY; use curve25519_dalek::edwards::EdwardsPoint; use curve25519_dalek::scalar::Scalar; use errors::SignatureError; use errors::InternalError; /// The length of a curve25519 EdDSA `Signature`, in bytes. pub const SIGNATURE_LENGTH: usize = 64; /// The length of a curve25519 EdDSA `SecretKey`, in bytes. pub const SECRET_KEY_LENGTH: usize = 32; /// The length of an ed25519 EdDSA `PublicKey`, in bytes. pub const PUBLIC_KEY_LENGTH: usize = 32; /// The length of an ed25519 EdDSA `Keypair`, in bytes. pub const KEYPAIR_LENGTH: usize = SECRET_KEY_LENGTH + PUBLIC_KEY_LENGTH; /// The length of the "key" portion of an "expanded" curve25519 EdDSA secret key, in bytes. const EXPANDED_SECRET_KEY_KEY_LENGTH: usize = 32; /// The length of the "nonce" portion of an "expanded" curve25519 EdDSA secret key, in bytes. const EXPANDED_SECRET_KEY_NONCE_LENGTH: usize = 32; /// The length of an "expanded" curve25519 EdDSA key, `ExpandedSecretKey`, in bytes. pub const EXPANDED_SECRET_KEY_LENGTH: usize = EXPANDED_SECRET_KEY_KEY_LENGTH + EXPANDED_SECRET_KEY_NONCE_LENGTH; /// An EdDSA signature. /// /// # Note /// /// These signatures, unlike the ed25519 signature reference implementation, are /// "detached"—that is, they do **not** include a copy of the message which has /// been signed. #[allow(non_snake_case)] #[derive(Copy, Eq, PartialEq)] #[repr(C)] pub struct Signature { /// `R` is an `EdwardsPoint`, formed by using an hash function with /// 512-bits output to produce the digest of: /// /// - the nonce half of the `ExpandedSecretKey`, and /// - the message to be signed. /// /// This digest is then interpreted as a `Scalar` and reduced into an /// element in ℤ/lℤ. The scalar is then multiplied by the distinguished /// basepoint to produce `R`, and `EdwardsPoint`. pub (crate) R: CompressedEdwardsY, /// `s` is a `Scalar`, formed by using an hash function with 512-bits output /// to produce the digest of: /// /// - the `r` portion of this `Signature`, /// - the `PublicKey` which should be used to verify this `Signature`, and /// - the message to be signed. /// /// This digest is then interpreted as a `Scalar` and reduced into an /// element in ℤ/lℤ. pub (crate) s: Scalar, } impl Clone for Signature { fn clone(&self) -> Self { *self } } impl Debug for Signature { fn fmt(&self, f: &mut ::core::fmt::Formatter) -> ::core::fmt::Result { write!(f, "Signature( R: {:?}, s: {:?} )", &self.R, &self.s) } } impl Signature { /// Convert this `Signature` to a byte array. #[inline] pub fn to_bytes(&self) -> [u8; SIGNATURE_LENGTH] { let mut signature_bytes: [u8; SIGNATURE_LENGTH] = [0u8; SIGNATURE_LENGTH]; signature_bytes[..32].copy_from_slice(&self.R.as_bytes()[..]); signature_bytes[32..].copy_from_slice(&self.s.as_bytes()[..]); signature_bytes } /// Construct a `Signature` from a slice of bytes. #[inline] pub fn from_bytes(bytes: &[u8]) -> Result<Signature, SignatureError> { if bytes.len() != SIGNATURE_LENGTH { return Err(SignatureError(InternalError::BytesLengthError{ name: "Signature", length: SIGNATURE_LENGTH })); } let mut lower: [u8; 32] = [0u8; 32]; let mut upper: [u8; 32] = [0u8; 32]; lower.copy_from_slice(&bytes[..32]); upper.copy_from_slice(&bytes[32..]); if upper[31] & 224 != 0 { return Err(SignatureError(InternalError::ScalarFormatError)); } Ok(Signature{ R: CompressedEdwardsY(lower), s: Scalar::from_bits(upper) }) } } #[cfg(feature = "serde")] impl Serialize for Signature { fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> where S: Serializer { serializer.serialize_bytes(&self.to_bytes()[..]) } } #[cfg(feature = "serde")] impl<'d> Deserialize<'d> for Signature { fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> where D: Deserializer<'d> { struct SignatureVisitor; impl<'d> Visitor<'d> for SignatureVisitor { type Value = Signature; fn expecting(&self, formatter: &mut ::core::fmt::Formatter) -> ::core::fmt::Result { formatter.write_str("An ed25519 signature as 64 bytes, as specified in RFC8032.") } fn visit_bytes<E>(self, bytes: &[u8]) -> Result<Signature, E> where E: SerdeError{ Signature::from_bytes(bytes).or(Err(SerdeError::invalid_length(bytes.len(), &self))) } } deserializer.deserialize_bytes(SignatureVisitor) } } /// An EdDSA secret key. #[repr(C)] #[derive(Default)] // we derive Default in order to use the clear() method in Drop pub struct SecretKey(pub (crate) [u8; SECRET_KEY_LENGTH]); impl Debug for SecretKey { fn fmt(&self, f: &mut ::core::fmt::Formatter) -> ::core::fmt::Result { write!(f, "SecretKey: {:?}", &self.0[..]) } } /// Overwrite secret key material with null bytes when it goes out of scope. impl Drop for SecretKey { fn drop(&mut self) { self.0.clear(); } } impl SecretKey { /// Expand this `SecretKey` into an `ExpandedSecretKey`. pub fn expand<D>(&self) -> ExpandedSecretKey where D: Digest<OutputSize = U64> + Default { ExpandedSecretKey::from_secret_key::<D>(&self) } /// Convert this secret key to a byte array. #[inline] pub fn to_bytes(&self) -> [u8; SECRET_KEY_LENGTH] { self.0 } /// View this secret key as a byte array. #[inline] pub fn as_bytes<'a>(&'a self) -> &'a [u8; SECRET_KEY_LENGTH] { &self.0 } /// Construct a `SecretKey` from a slice of bytes. /// /// # Example /// /// ``` /// # extern crate ed25519_dalek; /// # /// use ed25519_dalek::SecretKey; /// use ed25519_dalek::SECRET_KEY_LENGTH; /// use ed25519_dalek::SignatureError; /// /// # 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, /// 068, 073, 197, 105, 123, 050, 105, 025, /// 112, 059, 172, 003, 028, 174, 127, 096, ]; /// /// let secret_key: SecretKey = SecretKey::from_bytes(&secret_key_bytes)?; /// # /// # Ok(secret_key) /// # } /// # /// # fn main() { /// # let result = doctest(); /// # assert!(result.is_ok()); /// # } /// ``` /// /// # Returns /// /// A `Result` whose okay value is an EdDSA `SecretKey` or whose error value /// is an `SignatureError` wrapping the internal error that occurred. #[inline] pub fn from_bytes(bytes: &[u8]) -> Result<SecretKey, SignatureError> { if bytes.len() != SECRET_KEY_LENGTH { return Err(SignatureError(InternalError::BytesLengthError{ name: "SecretKey", length: SECRET_KEY_LENGTH })); } let mut bits: [u8; 32] = [0u8; 32]; bits.copy_from_slice(&bytes[..32]); Ok(SecretKey(bits)) } /// Generate a `SecretKey` from a `csprng`. /// /// # Example /// /// ``` /// extern crate rand; /// extern crate sha2; /// extern crate ed25519_dalek; /// /// # #[cfg(feature = "std")] /// # fn main() { /// # /// use rand::Rng; /// use rand::OsRng; /// use sha2::Sha512; /// use ed25519_dalek::PublicKey; /// use ed25519_dalek::SecretKey; /// use ed25519_dalek::Signature; /// /// let mut csprng: OsRng = OsRng::new().unwrap(); /// let secret_key: SecretKey = SecretKey::generate(&mut csprng); /// # } /// # /// # #[cfg(not(feature = "std"))] /// # fn main() { } /// ``` /// /// Afterwards, you can generate the corresponding public—provided you also /// supply a hash function which implements the `Digest` and `Default` /// traits, and which returns 512 bits of output—via: /// /// ``` /// # extern crate rand; /// # extern crate sha2; /// # extern crate ed25519_dalek; /// # /// # fn main() { /// # /// # use rand::Rng; /// # use rand::ChaChaRng; /// # use rand::SeedableRng; /// # use sha2::Sha512; /// # use ed25519_dalek::PublicKey; /// # use ed25519_dalek::SecretKey; /// # use ed25519_dalek::Signature; /// # /// # let mut csprng: ChaChaRng = ChaChaRng::from_seed([0u8; 32]); /// # let secret_key: SecretKey = SecretKey::generate(&mut csprng); /// /// let public_key: PublicKey = PublicKey::from_secret::<Sha512>(&secret_key); /// # } /// ``` /// /// The standard hash function used for most ed25519 libraries is SHA-512, /// which is available with `use sha2::Sha512` as in the example above. /// Other suitable hash functions include Keccak-512 and Blake2b-512. /// /// # Input /// /// A CSPRNG with a `fill_bytes()` method, e.g. `rand::ChaChaRng` pub fn generate<T>(csprng: &mut T) -> SecretKey where T: CryptoRng + Rng, { let mut sk: SecretKey = SecretKey([0u8; 32]); csprng.fill_bytes(&mut sk.0); sk } } #[cfg(feature = "serde")] impl Serialize for SecretKey { fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> where S: Serializer { serializer.serialize_bytes(self.as_bytes()) } } #[cfg(feature = "serde")] impl<'d> Deserialize<'d> for SecretKey { fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> where D: Deserializer<'d> { struct SecretKeyVisitor; impl<'d> Visitor<'d> for SecretKeyVisitor { type Value = SecretKey; fn expecting(&self, formatter: &mut ::core::fmt::Formatter) -> ::core::fmt::Result { formatter.write_str("An ed25519 secret key as 32 bytes, as specified in RFC8032.") } fn visit_bytes<E>(self, bytes: &[u8]) -> Result<SecretKey, E> where E: SerdeError { SecretKey::from_bytes(bytes).or(Err(SerdeError::invalid_length(bytes.len(), &self))) } } deserializer.deserialize_bytes(SecretKeyVisitor) } } /// An "expanded" secret key. /// /// This is produced by using an hash function with 512-bits output to digest a /// `SecretKey`. The output digest is then split in half, the lower half being /// the actual `key` used to sign messages, after twiddling with some bits.¹ The /// upper half is used a sort of half-baked, ill-designed² pseudo-domain-separation /// "nonce"-like thing, which is used during signature production by /// concatenating it with the message to be signed before the message is hashed. // // ¹ This results in a slight bias towards non-uniformity at one spectrum of // the range of valid keys. Oh well: not my idea; not my problem. // // ² It is the author's view (specifically, isis agora lovecruft, in the event // you'd like to complain about me, again) that this is "ill-designed" because // this doesn't actually provide true hash domain separation, in that in many // real-world applications a user wishes to have one key which is used in // several contexts (such as within tor, which does does domain separation // manually by pre-concatenating static strings to messages to achieve more // robust domain separation). In other real-world applications, such as // bitcoind, a user might wish to have one master keypair from which others are // derived (à la BIP32) and different domain separators between keys derived at // different levels (and similarly for tree-based key derivation constructions, // such as hash-based signatures). Leaving the domain separation to // application designers, who thus far have produced incompatible, // slightly-differing, ad hoc domain separation (at least those application // designers who knew enough cryptographic theory to do so!), is therefore a // bad design choice on the part of the cryptographer designing primitives // which should be simple and as foolproof as possible to use for // non-cryptographers. Further, later in the ed25519 signature scheme, as // specified in RFC8032, the public key is added into *another* hash digest // (along with the message, again); it is unclear to this author why there's // not only one but two poorly-thought-out attempts at domain separation in the // same signature scheme, and which both fail in exactly the same way. For a // better-designed, Schnorr-based signature scheme, see Trevor Perrin's work on // "generalised EdDSA" and "VXEdDSA". #[repr(C)] #[derive(Default)] // we derive Default in order to use the clear() method in Drop pub struct ExpandedSecretKey { pub (crate) key: Scalar, pub (crate) nonce: [u8; 32], } /// Overwrite secret key material with null bytes when it goes out of scope. impl Drop for ExpandedSecretKey { fn drop(&mut self) { self.key.clear(); self.nonce.clear(); } } #[cfg(feature = "sha2")] impl<'a> From<&'a SecretKey> for ExpandedSecretKey { /// Construct an `ExpandedSecretKey` from a `SecretKey`. /// /// # Examples /// /// ``` /// # extern crate rand; /// # extern crate sha2; /// # extern crate ed25519_dalek; /// # /// # #[cfg(all(feature = "std", feature = "sha2"))] /// # fn main() { /// # /// use rand::{Rng, OsRng}; /// use sha2::Sha512; /// use ed25519_dalek::{SecretKey, ExpandedSecretKey}; /// /// let mut csprng: OsRng = OsRng::new().unwrap(); /// let secret_key: SecretKey = SecretKey::generate(&mut csprng); /// let expanded_secret_key: ExpandedSecretKey = ExpandedSecretKey::from(&secret_key); /// # } /// # /// # #[cfg(any(not(feature = "std"), not(feature = "sha2")))] /// # fn main() {} /// ``` fn from(secret_key: &'a SecretKey) -> ExpandedSecretKey { ExpandedSecretKey::from_secret_key::<Sha512>(&secret_key) } } impl ExpandedSecretKey { /// Convert this `ExpandedSecretKey` into an array of 64 bytes. /// /// # Returns /// /// An array of 64 bytes. The first 32 bytes represent the "expanded" /// secret key, and the last 32 bytes represent the "domain-separation" /// "nonce". /// /// # Examples /// /// ``` /// # extern crate rand; /// # extern crate sha2; /// # extern crate ed25519_dalek; /// # /// # #[cfg(all(feature = "sha2", feature = "std"))] /// # fn main() { /// # /// use rand::{Rng, OsRng}; /// use sha2::Sha512; /// use ed25519_dalek::{SecretKey, ExpandedSecretKey}; /// /// let mut csprng: OsRng = OsRng::new().unwrap(); /// let secret_key: SecretKey = SecretKey::generate(&mut csprng); /// let expanded_secret_key: ExpandedSecretKey = ExpandedSecretKey::from(&secret_key); /// let expanded_secret_key_bytes: [u8; 64] = expanded_secret_key.to_bytes(); /// /// assert!(&expanded_secret_key_bytes[..] != &[0u8; 64][..]); /// # } /// # /// # #[cfg(any(not(feature = "sha2"), not(feature = "std")))] /// # fn main() { } /// ``` #[inline] pub fn to_bytes(&self) -> [u8; EXPANDED_SECRET_KEY_LENGTH] { let mut bytes: [u8; 64] = [0u8; 64]; bytes[..32].copy_from_slice(self.key.as_bytes()); bytes[32..].copy_from_slice(&self.nonce[..]); bytes } /// Construct an `ExpandedSecretKey` from a slice of bytes. /// /// # Returns /// /// A `Result` whose okay value is an EdDSA `ExpandedSecretKey` or whose /// error value is an `SignatureError` describing the error that occurred. /// /// # Examples /// /// ``` /// # extern crate rand; /// # extern crate sha2; /// # extern crate ed25519_dalek; /// # /// # #[cfg(all(feature = "sha2", feature = "std"))] /// # fn do_test() -> Result<ExpandedSecretKey, SignatureError> { /// # /// use rand::{Rng, OsRng}; /// use ed25519_dalek::{SecretKey, ExpandedSecretKey}; /// use ed25519_dalek::SignatureError; /// /// let mut csprng: OsRng = OsRng::new().unwrap(); /// let secret_key: SecretKey = SecretKey::generate(&mut csprng); /// let expanded_secret_key: ExpandedSecretKey = ExpandedSecretKey::from(&secret_key); /// let bytes: [u8; 64] = expanded_secret_key.to_bytes(); /// let expanded_secret_key_again = ExpandedSecretKey::from_bytes(&bytes)?; /// # /// # Ok(expanded_secret_key_again) /// # } /// # /// # #[cfg(all(feature = "sha2", feature = "std"))] /// # fn main() { /// # let result = do_test(); /// # assert!(result.is_ok()); /// # } /// # /// # #[cfg(any(not(feature = "sha2"), not(feature = "std")))] /// # fn main() { } /// ``` #[inline] pub fn from_bytes(bytes: &[u8]) -> Result<ExpandedSecretKey, SignatureError> { if bytes.len() != EXPANDED_SECRET_KEY_LENGTH { return Err(SignatureError(InternalError::BytesLengthError{ name: "ExpandedSecretKey", length: EXPANDED_SECRET_KEY_LENGTH })); } let mut lower: [u8; 32] = [0u8; 32]; let mut upper: [u8; 32] = [0u8; 32]; lower.copy_from_slice(&bytes[00..32]); upper.copy_from_slice(&bytes[32..64]); Ok(ExpandedSecretKey{ key: Scalar::from_bits(lower), nonce: upper }) } /// Construct an `ExpandedSecretKey` from a `SecretKey`, using hash function `D`. /// /// # Examples /// /// ``` /// # extern crate rand; /// # extern crate sha2; /// # extern crate ed25519_dalek; /// # /// # #[cfg(all(feature = "std", feature = "sha2"))] /// # fn main() { /// # /// use rand::{Rng, OsRng}; /// use sha2::Sha512; /// use ed25519_dalek::{SecretKey, ExpandedSecretKey}; /// /// let mut csprng: OsRng = OsRng::new().unwrap(); /// let secret_key: SecretKey = SecretKey::generate(&mut csprng); /// let expanded_secret_key: ExpandedSecretKey = ExpandedSecretKey::from_secret_key::<Sha512>(&secret_key); /// # } /// # /// # #[cfg(any(not(feature = "sha2"), not(feature = "std")))] /// # fn main() { } /// ``` pub fn from_secret_key<D>(secret_key: &SecretKey) -> ExpandedSecretKey where D: Digest<OutputSize = U64> + Default { let mut h: D = D::default(); let mut hash: [u8; 64] = [0u8; 64]; let mut lower: [u8; 32] = [0u8; 32]; let mut upper: [u8; 32] = [0u8; 32]; h.input(secret_key.as_bytes()); hash.copy_from_slice(h.result().as_slice()); lower.copy_from_slice(&hash[00..32]); upper.copy_from_slice(&hash[32..64]); lower[0] &= 248; lower[31] &= 63; lower[31] |= 64; ExpandedSecretKey{ key: Scalar::from_bits(lower), nonce: upper, } } /// Sign a message with this `ExpandedSecretKey`. #[allow(non_snake_case)] pub fn sign<D>(&self, message: &[u8], public_key: &PublicKey) -> Signature where D: Digest<OutputSize = U64> + Default { let mut h: D = D::default(); let R: CompressedEdwardsY; let r: Scalar; let s: Scalar; let k: Scalar; h.input(&self.nonce); h.input(&message); r = Scalar::from_hash(h); R = (&r * &constants::ED25519_BASEPOINT_TABLE).compress(); h = D::default(); h.input(R.as_bytes()); h.input(public_key.as_bytes()); h.input(&message); k = Scalar::from_hash(h); s = &(&k * &self.key) + &r; Signature{ R, s } } /// Sign a `prehashed_message` with this `ExpandedSecretKey` using the /// Ed25519ph algorithm defined in [RFC8032 §5.1][rfc8032]. /// /// # Inputs /// /// * `prehashed_message` is an instantiated hash digest with 512-bits of /// output which has had the message to be signed previously fed into its /// state. /// * `public_key` is a [`PublicKey`] which corresponds to this secret key. /// * `context` is an optional context string, up to 255 bytes inclusive, /// which may be used to provide additional domain separation. If not /// set, this will default to an empty string. /// /// # Returns /// /// An Ed25519ph [`Signature`] on the `prehashed_message`. /// /// [rfc8032]: https://tools.ietf.org/html/rfc8032#section-5.1 #[allow(non_snake_case)] pub fn sign_prehashed<D>(&self, prehashed_message: D, public_key: &PublicKey, context: Option<&'static [u8]>) -> Signature where D: Digest<OutputSize = U64> + Default { let mut h: D; let mut prehash: [u8; 64] = [0u8; 64]; let R: CompressedEdwardsY; let r: Scalar; let s: Scalar; let k: Scalar; let ctx: &[u8] = context.unwrap_or(b""); // By default, the context is an empty string. debug_assert!(ctx.len() <= 255, "The context must not be longer than 255 octets."); let ctx_len: u8 = ctx.len() as u8; // Get the result of the pre-hashed message. prehash.copy_from_slice(prehashed_message.result().as_slice()); // This is the dumbest, ten-years-late, non-admission of fucking up the // domain separation I have ever seen. Why am I still required to put // the upper half "prefix" of the hashed "secret key" in here? Why // can't the user just supply their own nonce and decide for themselves // whether or not they want a deterministic signature scheme? Why does // the message go into what's ostensibly the signature domain separation // hash? Why wasn't there always a way to provide a context string? // // ... // // This is a really fucking stupid bandaid, and the damned scheme is // still bleeding from malleability, for fuck's sake. h = D::default() .chain(b"SigEd25519 no Ed25519 collisions") .chain(&[1]) // Ed25519ph .chain(&[ctx_len]) .chain(ctx) .chain(&self.nonce) .chain(&prehash[..]); r = Scalar::from_hash(h); R = (&r * &constants::ED25519_BASEPOINT_TABLE).compress(); h = D::default() .chain(b"SigEd25519 no Ed25519 collisions") .chain(&[1]) // Ed25519ph .chain(&[ctx_len]) .chain(ctx) .chain(R.as_bytes()) .chain(public_key.as_bytes()) .chain(&prehash[..]); k = Scalar::from_hash(h); s = &(&k * &self.key) + &r; Signature{ R, s } } } #[cfg(feature = "serde")] impl Serialize for ExpandedSecretKey { fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> where S: Serializer { serializer.serialize_bytes(&self.to_bytes()[..]) } } #[cfg(feature = "serde")] impl<'d> Deserialize<'d> for ExpandedSecretKey { fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> where D: Deserializer<'d> { struct ExpandedSecretKeyVisitor; impl<'d> Visitor<'d> for ExpandedSecretKeyVisitor { type Value = ExpandedSecretKey; fn expecting(&self, formatter: &mut ::core::fmt::Formatter) -> ::core::fmt::Result { formatter.write_str("An ed25519 expanded secret key as 64 bytes, as specified in RFC8032.") } fn visit_bytes<E>(self, bytes: &[u8]) -> Result<ExpandedSecretKey, E> where E: SerdeError { ExpandedSecretKey::from_bytes(bytes).or(Err(SerdeError::invalid_length(bytes.len(), &self))) } } deserializer.deserialize_bytes(ExpandedSecretKeyVisitor) } } /// An ed25519 public key. #[derive(Copy, Clone, Default, Eq, PartialEq)] #[repr(C)] pub struct PublicKey(pub (crate) CompressedEdwardsY); impl Debug for PublicKey { fn fmt(&self, f: &mut ::core::fmt::Formatter) -> ::core::fmt::Result { write!(f, "PublicKey( CompressedEdwardsY( {:?} ))", self.0) } } impl PublicKey { /// Convert this public key to a byte array. #[inline] pub fn to_bytes(&self) -> [u8; PUBLIC_KEY_LENGTH] { self.0.to_bytes() } /// View this public key as a byte array. #[inline] pub fn as_bytes<'a>(&'a self) -> &'a [u8; PUBLIC_KEY_LENGTH] { &(self.0).0 } /// Construct a `PublicKey` from a slice of bytes. /// /// # Warning /// /// The caller is responsible for ensuring that the bytes passed into this /// method actually represent a `curve25519_dalek::curve::CompressedEdwardsY` /// and that said compressed point is actually a point on the curve. /// /// # Example /// /// ``` /// # extern crate ed25519_dalek; /// # /// use ed25519_dalek::PublicKey; /// use ed25519_dalek::PUBLIC_KEY_LENGTH; /// use ed25519_dalek::SignatureError; /// /// # 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]; /// /// let public_key = PublicKey::from_bytes(&public_key_bytes)?; /// # /// # Ok(public_key) /// # } /// # /// # fn main() { /// # doctest(); /// # } /// ``` /// /// # Returns /// /// A `Result` whose okay value is an EdDSA `PublicKey` or whose error value /// is an `SignatureError` describing the error that occurred. #[inline] pub fn from_bytes(bytes: &[u8]) -> Result<PublicKey, SignatureError> { if bytes.len() != PUBLIC_KEY_LENGTH { return Err(SignatureError(InternalError::BytesLengthError{ name: "PublicKey", length: PUBLIC_KEY_LENGTH })); } let mut bits: [u8; 32] = [0u8; 32]; bits.copy_from_slice(&bytes[..32]); Ok(PublicKey(CompressedEdwardsY(bits))) } /// Derive this public key from its corresponding `SecretKey`. #[allow(unused_assignments)] pub fn from_secret<D>(secret_key: &SecretKey) -> PublicKey where D: Digest<OutputSize = U64> + Default { let mut h: D = D::default(); let mut hash: [u8; 64] = [0u8; 64]; let mut digest: [u8; 32] = [0u8; 32]; h.input(secret_key.as_bytes()); hash.copy_from_slice(h.result().as_slice()); digest.copy_from_slice(&hash[..32]); PublicKey::mangle_scalar_bits_and_multiply_by_basepoint_to_produce_public_key(&mut digest) } /// Derive this public key from its corresponding `ExpandedSecretKey`. pub fn from_expanded_secret(expanded_secret_key: &ExpandedSecretKey) -> PublicKey { let mut bits: [u8; 32] = expanded_secret_key.key.to_bytes(); PublicKey::mangle_scalar_bits_and_multiply_by_basepoint_to_produce_public_key(&mut bits) } /// Internal utility function for mangling the bits of a (formerly /// mathematically well-defined) "scalar" and multiplying it to produce a /// public key. fn mangle_scalar_bits_and_multiply_by_basepoint_to_produce_public_key(bits: &mut [u8; 32]) -> PublicKey { bits[0] &= 248; bits[31] &= 127; bits[31] |= 64; let pk = (&Scalar::from_bits(*bits) * &constants::ED25519_BASEPOINT_TABLE).compress().to_bytes(); PublicKey(CompressedEdwardsY(pk)) } /// Verify a signature on a message with this keypair's public key. /// /// # Return /// /// 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 R: EdwardsPoint; let k: Scalar; let A: EdwardsPoint = match self.0.decompress() { Some(x) => x, None => return Err(SignatureError(InternalError::PointDecompressionError)), }; h.input(signature.R.as_bytes()); h.input(self.as_bytes()); h.input(&message); k = Scalar::from_hash(h); R = EdwardsPoint::vartime_double_scalar_mul_basepoint(&k, &(-A), &signature.s); if R.compress() == signature.R { Ok(()) } else { Err(SignatureError(InternalError::VerifyError)) } } /// Verify a `signature` on a `prehashed_message` using the Ed25519ph algorithm. /// /// # Inputs /// /// * `prehashed_message` is an instantiated hash digest with 512-bits of /// output which has had the message to be signed previously fed into its /// state. /// * `context` is an optional context string, up to 255 bytes inclusive, /// which may be used to provide additional domain separation. If not /// set, this will default to an empty string. /// * `signature` is a purported Ed25519ph [`Signature`] on the `prehashed_message`. /// /// # Returns /// /// Returns `true` if the `signature` was a valid signature created by this /// `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) -> Result<(), SignatureError> where D: Digest<OutputSize = U64> + Default { let mut h: D = D::default(); let R: EdwardsPoint; let k: Scalar; let ctx: &[u8] = context.unwrap_or(b""); debug_assert!(ctx.len() <= 255, "The context must not be longer than 255 octets."); let A: EdwardsPoint = match self.0.decompress() { Some(x) => x, None => return Err(SignatureError(InternalError::PointDecompressionError)), }; h.input(b"SigEd25519 no Ed25519 collisions"); h.input(&[1]); // Ed25519ph h.input(&[ctx.len() as u8]); h.input(ctx); h.input(signature.R.as_bytes()); h.input(self.as_bytes()); h.input(prehashed_message.result().as_slice()); k = Scalar::from_hash(h); R = EdwardsPoint::vartime_double_scalar_mul_basepoint(&k, &(-A), &signature.s); if R.compress() == signature.R { Ok(()) } else { Err(SignatureError(InternalError::VerifyError)) } } } impl From<ExpandedSecretKey> for PublicKey { fn from(source: ExpandedSecretKey) -> PublicKey { PublicKey::from_expanded_secret(&source) } } /// Verify a batch of `signatures` on `messages` with their respective `public_keys`. /// /// # Inputs /// /// * `messages` is a slice of byte slices, one per signed message. /// * `signatures` is a slice of `Signature`s. /// * `public_keys` is a slice of `PublicKey`s. /// * `csprng` is an implementation of `Rng + CryptoRng`, such as `rand::ThreadRng`. /// /// # Panics /// /// This function will panic if the `messages, `signatures`, and `public_keys` /// slices are not equal length. /// /// # Returns /// /// * A `Result` whose `Ok` value is an emtpy tuple and whose `Err` value is a /// `SignatureError` containing a description of the internal error which /// occured. /// /// # Examples /// /// ``` /// extern crate ed25519_dalek; /// extern crate rand; /// extern crate sha2; /// /// use ed25519_dalek::verify_batch; /// use ed25519_dalek::Keypair; /// use ed25519_dalek::PublicKey; /// use ed25519_dalek::Signature; /// use rand::thread_rng; /// use sha2::Sha512; /// /// # fn main() { /// let mut csprng = thread_rng(); /// let keypairs: Vec<Keypair> = (0..64).map(|_| Keypair::generate::<Sha512, _>(&mut csprng)).collect(); /// let msg: &[u8] = b"They're good dogs Brant"; /// let messages: Vec<&[u8]> = (0..64).map(|_| msg).collect(); /// let signatures: Vec<Signature> = keypairs.iter().map(|key| key.sign::<Sha512>(&msg)).collect(); /// let public_keys: Vec<PublicKey> = keypairs.iter().map(|key| key.public).collect(); /// /// let result = verify_batch::<Sha512>(&messages[..], &signatures[..], &public_keys[..]); /// assert!(result.is_ok()); /// # } /// ``` #[cfg(any(feature = "alloc", feature = "std"))] #[allow(non_snake_case)] pub fn verify_batch<D>(messages: &[&[u8]], signatures: &[Signature], public_keys: &[PublicKey]) -> Result<(), SignatureError> where D: Digest<OutputSize = U64> + Default { const ASSERT_MESSAGE: &'static [u8] = b"The number of messages, signatures, and public keys must be equal."; assert!(signatures.len() == messages.len(), ASSERT_MESSAGE); assert!(signatures.len() == public_keys.len(), ASSERT_MESSAGE); assert!(public_keys.len() == messages.len(), ASSERT_MESSAGE); #[cfg(feature = "alloc")] use alloc::vec::Vec; #[cfg(feature = "std")] use std::vec::Vec; use core::iter::once; use rand::thread_rng; use curve25519_dalek::traits::IsIdentity; use curve25519_dalek::traits::VartimeMultiscalarMul; // Select a random 128-bit scalar for each signature. let zs: Vec<Scalar> = signatures .iter() .map(|_| Scalar::from(thread_rng().gen::<u128>())) .collect(); // Compute the basepoint coefficient, ∑ s[i]z[i] (mod l) let B_coefficient: Scalar = signatures .iter() .map(|sig| sig.s) .zip(zs.iter()) .map(|(s, z)| z * s) .sum(); // Compute H(R || A || M) for each (signature, public_key, message) triplet let hrams = (0..signatures.len()).map(|i| { let mut h: D = D::default(); h.input(signatures[i].R.as_bytes()); h.input(public_keys[i].as_bytes()); h.input(&messages[i]); Scalar::from_hash(h) }); // Multiply each H(R || A || M) by the random value let zhrams = hrams.zip(zs.iter()).map(|(hram, z)| hram * z); let Rs = signatures.iter().map(|sig| sig.R.decompress()); let As = public_keys.iter().map(|pk| pk.0.decompress()); let B = once(Some(constants::ED25519_BASEPOINT_POINT)); // Compute (-∑ z[i]s[i] (mod l)) B + ∑ z[i]R[i] + ∑ (z[i]H(R||A||M)[i] (mod l)) A[i] = 0 let id = EdwardsPoint::optional_multiscalar_mul( once(-B_coefficient).chain(zs.iter().cloned()).chain(zhrams), B.chain(Rs).chain(As), ).ok_or_else(|| SignatureError(InternalError::VerifyError))?; if id.is_identity() { Ok(()) } else { Err(SignatureError(InternalError::VerifyError)) } } #[cfg(feature = "serde")] impl Serialize for PublicKey { fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> where S: Serializer { serializer.serialize_bytes(self.as_bytes()) } } #[cfg(feature = "serde")] impl<'d> Deserialize<'d> for PublicKey { fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> where D: Deserializer<'d> { struct PublicKeyVisitor; impl<'d> Visitor<'d> for PublicKeyVisitor { type Value = PublicKey; fn expecting(&self, formatter: &mut ::core::fmt::Formatter) -> ::core::fmt::Result { formatter.write_str("An ed25519 public key as a 32-byte compressed point, as specified in RFC8032") } fn visit_bytes<E>(self, bytes: &[u8]) -> Result<PublicKey, E> where E: SerdeError { PublicKey::from_bytes(bytes).or(Err(SerdeError::invalid_length(bytes.len(), &self))) } } deserializer.deserialize_bytes(PublicKeyVisitor) } } /// An ed25519 keypair. #[derive(Debug, Default)] // we derive Default in order to use the clear() method in Drop #[repr(C)] pub struct Keypair { /// The secret half of this keypair. pub secret: SecretKey, /// The public half of this keypair. pub public: PublicKey, } impl Keypair { /// Convert this keypair to bytes. /// /// # Returns /// /// An array of bytes, `[u8; KEYPAIR_LENGTH]`. The first /// `SECRET_KEY_LENGTH` of bytes is the `SecretKey`, and the next /// `PUBLIC_KEY_LENGTH` bytes is the `PublicKey` (the same as other /// libraries, such as [Adam Langley's ed25519 Golang /// implementation](https://github.com/agl/ed25519/)). pub fn to_bytes(&self) -> [u8; KEYPAIR_LENGTH] { let mut bytes: [u8; KEYPAIR_LENGTH] = [0u8; KEYPAIR_LENGTH]; bytes[..SECRET_KEY_LENGTH].copy_from_slice(self.secret.as_bytes()); bytes[SECRET_KEY_LENGTH..].copy_from_slice(self.public.as_bytes()); bytes } /// Construct a `Keypair` from the bytes of a `PublicKey` and `SecretKey`. /// /// # Inputs /// /// * `bytes`: an `&[u8]` representing the scalar for the secret key, and a /// compressed Edwards-Y coordinate of a point on curve25519, both as bytes. /// (As obtained from `Keypair::to_bytes()`.) /// /// # Warning /// /// Absolutely no validation is done on the key. If you give this function /// bytes which do not represent a valid point, or which do not represent /// corresponding parts of the key, then your `Keypair` will be broken and /// it will be your fault. /// /// # Returns /// /// A `Result` whose okay value is an EdDSA `Keypair` or whose error value /// 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(SignatureError(InternalError::BytesLengthError{ name: "Keypair", length: KEYPAIR_LENGTH})); } let secret = SecretKey::from_bytes(&bytes[..SECRET_KEY_LENGTH])?; let public = PublicKey::from_bytes(&bytes[SECRET_KEY_LENGTH..])?; Ok(Keypair{ secret: secret, public: public }) } /// Generate an ed25519 keypair. /// /// # Example /// /// ``` /// extern crate rand; /// extern crate sha2; /// extern crate ed25519_dalek; /// /// # #[cfg(all(feature = "std", feature = "sha2"))] /// # fn main() { /// /// use rand::Rng; /// use rand::OsRng; /// use sha2::Sha512; /// use ed25519_dalek::Keypair; /// use ed25519_dalek::Signature; /// /// let mut csprng: OsRng = OsRng::new().unwrap(); /// let keypair: Keypair = Keypair::generate::<Sha512, _>(&mut csprng); /// /// # } /// # /// # #[cfg(any(not(feature = "sha2"), not(feature = "std")))] /// # fn main() { } /// ``` /// /// # Input /// /// A CSPRNG with a `fill_bytes()` method, e.g. `rand::ChaChaRng`. /// /// The caller must also supply a hash function which implements the /// `Digest` and `Default` traits, and which returns 512 bits of output. /// The standard hash function used for most ed25519 libraries is SHA-512, /// which is available with `use sha2::Sha512` as in the example above. /// Other suitable hash functions include Keccak-512 and Blake2b-512. pub fn generate<D, R>(csprng: &mut R) -> Keypair where D: Digest<OutputSize = U64> + Default, R: CryptoRng + Rng, { let sk: SecretKey = SecretKey::generate(csprng); let pk: PublicKey = PublicKey::from_secret::<D>(&sk); Keypair{ public: pk, secret: sk } } /// Sign a message with this keypair's secret key. pub fn sign<D>(&self, message: &[u8]) -> Signature where D: Digest<OutputSize = U64> + Default { self.secret.expand::<D>().sign::<D>(&message, &self.public) } /// Sign a `prehashed_message` with this `Keypair` using the /// Ed25519ph algorithm defined in [RFC8032 §5.1][rfc8032]. /// /// # Inputs /// /// * `prehashed_message` is an instantiated hash digest with 512-bits of /// output which has had the message to be signed previously fed into its /// state. /// * `context` is an optional context string, up to 255 bytes inclusive, /// which may be used to provide additional domain separation. If not /// set, this will default to an empty string. /// /// # Returns /// /// An Ed25519ph [`Signature`] on the `prehashed_message`. /// /// # Examples /// /// ``` /// extern crate ed25519_dalek; /// extern crate rand; /// extern crate sha2; /// /// use ed25519_dalek::Keypair; /// use ed25519_dalek::Signature; /// use rand::thread_rng; /// use rand::ThreadRng; /// use sha2::Sha512; /// /// # #[cfg(all(feature = "std", feature = "sha2"))] /// # fn main() { /// let mut csprng: ThreadRng = thread_rng(); /// let keypair: Keypair = Keypair::generate::<Sha512, _>(&mut csprng); /// let message: &[u8] = b"All I want is to pet all of the dogs."; /// /// // Create a hash digest object which we'll feed the message into: /// let prehashed: Sha512 = Sha512::default(); /// /// prehashed.input(message); /// # } /// # /// # #[cfg(any(not(feature = "sha2"), not(feature = "std")))] /// # fn main() { } /// ``` /// /// If you want, you can optionally pass a "context". It is generally a /// good idea to choose a context and try to make it unique to your project /// and this specific usage of signatures. /// /// For example, without this, if you were to [convert your OpenPGP key /// to a Bitcoin key][terrible_idea] (just as an example, and also Don't /// Ever Do That) and someone tricked you into signing an "email" which was /// actually a Bitcoin transaction moving all your magic internet money to /// their address, it'd be a valid transaction. /// /// By adding a context, this trick becomes impossible, because the context /// is concatenated into the hash, which is then signed. So, going with the /// previous example, if your bitcoin wallet used a context of /// "BitcoinWalletAppTxnSigning" and OpenPGP used a context (this is likely /// the least of their safety problems) of "GPGsCryptoIsntConstantTimeLol", /// then the signatures produced by both could never match the other, even /// if they signed the exact same message with the same key. /// /// Let's add a context for good measure (remember, you'll want to choose /// your own!): /// /// ``` /// # extern crate ed25519_dalek; /// # extern crate rand; /// # extern crate sha2; /// # /// # use ed25519_dalek::Keypair; /// # use ed25519_dalek::Signature; /// # use rand::thread_rng; /// # use rand::ThreadRng; /// # use sha2::Sha512; /// # /// # #[cfg(all(feature = "std", feature = "sha2"))] /// # fn main() { /// # let mut csprng: ThreadRng = thread_rng(); /// # let keypair: Keypair = Keypair::generate::<Sha512, _>(&mut csprng); /// # let message: &[u8] = b"All I want is to pet all of the dogs."; /// # let prehashed: Sha512 = Sha512::default(); /// # prehashed.input(message); /// # /// let context: &[u8] = b"Ed25519DalekSignPrehashedDoctest"; /// /// let sig: Signature = keypair.sign_prehashed(prehashed, Some(context)); /// # } /// # /// # #[cfg(any(not(feature = "sha2"), not(feature = "std")))] /// # fn main() { } /// ``` /// /// [rfc8032]: https://tools.ietf.org/html/rfc8032#section-5.1 /// [terrible_idea]: https://github.com/isislovecruft/scripts/blob/master/gpgkey2bc.py pub fn sign_prehashed<D>(&self, prehashed_message: D, context: Option<&'static [u8]>) -> Signature where D: Digest<OutputSize = U64> + Default { self.secret.expand::<D>().sign_prehashed::<D>(prehashed_message, &self.public, context) } /// Verify a signature on a message with this keypair's public key. pub fn verify<D>(&self, message: &[u8], signature: &Signature) -> Result<(), SignatureError> where D: Digest<OutputSize = U64> + Default { self.public.verify::<D>(message, signature) } /// Verify a `signature` on a `prehashed_message` using the Ed25519ph algorithm. /// /// # Inputs /// /// * `prehashed_message` is an instantiated hash digest with 512-bits of /// output which has had the message to be signed previously fed into its /// state. /// * `context` is an optional context string, up to 255 bytes inclusive, /// which may be used to provide additional domain separation. If not /// set, this will default to an empty string. /// * `signature` is a purported Ed25519ph [`Signature`] on the `prehashed_message`. /// /// # Returns /// /// Returns `true` if the `signature` was a valid signature created by this /// `Keypair` on the `prehashed_message`. /// /// # Examples /// /// ``` /// extern crate ed25519_dalek; /// extern crate rand; /// extern crate sha2; /// /// use ed25519_dalek::Keypair; /// use ed25519_dalek::Signature; /// use rand::thread_rng; /// use rand::ThreadRng; /// use sha2::Sha512; /// /// # #[cfg(all(feature = "std", feature = "sha2"))] /// # fn main() { /// let mut csprng: ThreadRng = thread_rng(); /// let keypair: Keypair = Keypair::generate::<Sha512, _>(&mut csprng); /// let message: &[u8] = b"All I want is to pet all of the dogs."; /// /// let prehashed: Sha512 = Sha512::default(); /// prehashed.input(message); /// /// let context: &[u8] = b"Ed25519DalekSignPrehashedDoctest"; /// /// let sig: Signature = keypair.sign_prehashed(prehashed, Some(context)); /// /// // The sha2::Sha512 struct doesn't implement Copy, so we'll have to create a new one: /// let prehashed_again: Sha512 = Sha512::default(); /// prehashed_again.input(message); /// /// let valid: bool = keypair.public.verify_prehashed(prehashed_again, context, sig); /// /// assert!(valid); /// # } /// # /// # #[cfg(any(not(feature = "sha2"), not(feature = "std")))] /// # fn main() { } /// ``` /// /// [rfc8032]: https://tools.ietf.org/html/rfc8032#section-5.1 pub fn verify_prehashed<D>(&self, prehashed_message: D, context: Option<&[u8]>, signature: &Signature) -> Result<(), SignatureError> where D: Digest<OutputSize = U64> + Default { self.public.verify_prehashed::<D>(prehashed_message, context, signature) } } #[cfg(feature = "serde")] impl Serialize for Keypair { fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> where S: Serializer { serializer.serialize_bytes(&self.to_bytes()[..]) } } #[cfg(feature = "serde")] impl<'d> Deserialize<'d> for Keypair { fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> where D: Deserializer<'d> { struct KeypairVisitor; impl<'d> Visitor<'d> for KeypairVisitor { type Value = Keypair; fn expecting(&self, formatter: &mut ::core::fmt::Formatter) -> ::core::fmt::Result { formatter.write_str("An ed25519 keypair, 64 bytes in total where the secret key is \ the first 32 bytes and is in unexpanded form, and the second \ 32 bytes is a compressed point for a public key.") } fn visit_bytes<E>(self, bytes: &[u8]) -> Result<Keypair, E> where E: SerdeError { let secret_key = SecretKey::from_bytes(&bytes[..SECRET_KEY_LENGTH]); let public_key = PublicKey::from_bytes(&bytes[SECRET_KEY_LENGTH..]); if secret_key.is_ok() && public_key.is_ok() { Ok(Keypair{ secret: secret_key.unwrap(), public: public_key.unwrap() }) } else { Err(SerdeError::invalid_length(bytes.len(), &self)) } } } deserializer.deserialize_bytes(KeypairVisitor) } } #[cfg(test)] mod test { use std::io::BufReader; use std::io::BufRead; use std::fs::File; use std::string::String; use std::vec::Vec; use rand::thread_rng; use rand::ChaChaRng; use rand::SeedableRng; use hex::FromHex; use sha2::Sha512; use super::*; #[cfg(all(test, feature = "serde"))] static PUBLIC_KEY: PublicKey = PublicKey(CompressedEdwardsY([ 130, 039, 155, 015, 062, 076, 188, 063, 124, 122, 026, 251, 233, 253, 225, 220, 014, 041, 166, 120, 108, 035, 254, 077, 160, 083, 172, 058, 219, 042, 086, 120, ])); #[cfg(all(test, feature = "serde"))] static SECRET_KEY: SecretKey = SecretKey([ 062, 070, 027, 163, 092, 182, 011, 003, 077, 234, 098, 004, 011, 127, 079, 228, 243, 187, 150, 073, 201, 137, 076, 022, 085, 251, 152, 002, 241, 042, 072, 054, ]); /// Signature with the above keypair of a blank message. #[cfg(all(test, feature = "serde"))] static SIGNATURE_BYTES: [u8; SIGNATURE_LENGTH] = [ 010, 126, 151, 143, 157, 064, 047, 001, 196, 140, 179, 058, 226, 152, 018, 102, 160, 123, 080, 016, 210, 086, 196, 028, 053, 231, 012, 157, 169, 019, 158, 063, 045, 154, 238, 007, 053, 185, 227, 229, 079, 108, 213, 080, 124, 252, 084, 167, 216, 085, 134, 144, 129, 149, 041, 081, 063, 120, 126, 100, 092, 059, 050, 011, ]; #[test] fn sign_verify() { // TestSignVerify let mut csprng: ChaChaRng; let keypair: Keypair; let good_sig: Signature; let bad_sig: Signature; let good: &[u8] = "test message".as_bytes(); let bad: &[u8] = "wrong message".as_bytes(); csprng = ChaChaRng::from_seed([0u8; 32]); keypair = Keypair::generate::<Sha512, _>(&mut csprng); good_sig = keypair.sign::<Sha512>(&good); bad_sig = keypair.sign::<Sha512>(&bad); assert!(keypair.verify::<Sha512>(&good, &good_sig).is_ok(), "Verification of a valid signature failed!"); 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).is_err(), "Verification of a signature on a different message passed!"); } // TESTVECTORS is taken from sign.input.gz in agl's ed25519 Golang // package. It is a selection of test cases from // http://ed25519.cr.yp.to/python/sign.input #[cfg(test)] #[cfg(not(release))] #[test] fn golden() { // TestGolden let mut line: String; let mut lineno: usize = 0; let f = File::open("TESTVECTORS"); if f.is_err() { println!("This test is only available when the code has been cloned \ from the git repository, since the TESTVECTORS file is large \ and is therefore not included within the distributed crate."); panic!(); } let file = BufReader::new(f.unwrap()); for l in file.lines() { lineno += 1; line = l.unwrap(); let parts: Vec<&str> = line.split(':').collect(); assert_eq!(parts.len(), 5, "wrong number of fields in line {}", lineno); let sec_bytes: Vec<u8> = FromHex::from_hex(&parts[0]).unwrap(); let pub_bytes: Vec<u8> = FromHex::from_hex(&parts[1]).unwrap(); let msg_bytes: Vec<u8> = FromHex::from_hex(&parts[2]).unwrap(); let sig_bytes: Vec<u8> = FromHex::from_hex(&parts[3]).unwrap(); let secret: SecretKey = SecretKey::from_bytes(&sec_bytes[..SECRET_KEY_LENGTH]).unwrap(); let public: PublicKey = PublicKey::from_bytes(&pub_bytes[..PUBLIC_KEY_LENGTH]).unwrap(); let keypair: Keypair = Keypair{ secret: secret, public: public }; // The signatures in the test vectors also include the message // at the end, but we just want R and S. let sig1: Signature = Signature::from_bytes(&sig_bytes[..64]).unwrap(); 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).is_ok(), "Signature verification failed on line {}", lineno); } } // From https://tools.ietf.org/html/rfc8032#section-7.3 #[test] fn ed25519ph_rf8032_test_vector() { let secret_key: &[u8] = b"833fe62409237b9d62ec77587520911e9a759cec1d19755b7da901b96dca3d42"; let public_key: &[u8] = b"ec172b93ad5e563bf4932c70e1245034c35467ef2efd4d64ebf819683467e2bf"; let message: &[u8] = b"616263"; let signature: &[u8] = b"98a70222f0b8121aa9d30f813d683f809e462b469c7ff87639499bb94e6dae4131f85042463c2a355a2003d062adf5aaa10b8c61e636062aaad11c2a26083406"; let sec_bytes: Vec<u8> = FromHex::from_hex(secret_key).unwrap(); let pub_bytes: Vec<u8> = FromHex::from_hex(public_key).unwrap(); let msg_bytes: Vec<u8> = FromHex::from_hex(message).unwrap(); let sig_bytes: Vec<u8> = FromHex::from_hex(signature).unwrap(); let secret: SecretKey = SecretKey::from_bytes(&sec_bytes[..SECRET_KEY_LENGTH]).unwrap(); let public: PublicKey = PublicKey::from_bytes(&pub_bytes[..PUBLIC_KEY_LENGTH]).unwrap(); let keypair: Keypair = Keypair{ secret: secret, public: public }; let sig1: Signature = Signature::from_bytes(&sig_bytes[..]).unwrap(); let mut prehash_for_signing: Sha512 = Sha512::default(); let mut prehash_for_verifying: Sha512 = Sha512::default(); prehash_for_signing.input(&msg_bytes[..]); prehash_for_verifying.input(&msg_bytes[..]); let sig2: Signature = keypair.sign_prehashed(prehash_for_signing, None); 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).is_ok(), "Could not verify ed25519ph signature!"); } #[test] fn ed25519ph_sign_verify() { let mut csprng: ChaChaRng; let keypair: Keypair; let good_sig: Signature; let bad_sig: Signature; let good: &[u8] = b"test message"; let bad: &[u8] = b"wrong message"; // ugh… there's no `impl Copy for Sha512`… i hope we can all agree these are the same hashes let mut prehashed_good1: Sha512 = Sha512::default(); prehashed_good1.input(good); let mut prehashed_good2: Sha512 = Sha512::default(); prehashed_good2.input(good); let mut prehashed_good3: Sha512 = Sha512::default(); prehashed_good3.input(good); let mut prehashed_bad1: Sha512 = Sha512::default(); prehashed_bad1.input(bad); let mut prehashed_bad2: Sha512 = Sha512::default(); prehashed_bad2.input(bad); let context: &[u8] = b"testing testing 1 2 3"; csprng = ChaChaRng::from_seed([0u8; 32]); keypair = Keypair::generate::<Sha512, _>(&mut csprng); 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).is_ok(), "Verification of a valid signature failed!"); 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).is_err(), "Verification of a signature on a different message passed!"); } #[test] fn verify_batch_seven_signatures() { let messages: [&[u8]; 7] = [ b"Watch closely everyone, I'm going to show you how to kill a god.", b"I'm not a cryptographer I just encrypt a lot.", b"Still not a cryptographer.", b"This is a test of the tsunami alert system. This is only a test.", b"Fuck dumbin' it down, spit ice, skip jewellery: Molotov cocktails on me like accessories.", b"Hey, I never cared about your bucks, so if I run up with a mask on, probably got a gas can too.", b"And I'm not here to fill 'er up. Nope, we came to riot, here to incite, we don't want any of your stuff.", ]; let mut csprng = thread_rng(); let mut keypairs: Vec<Keypair> = Vec::new(); let mut signatures: Vec<Signature> = Vec::new(); for i in 0..messages.len() { let keypair: Keypair = Keypair::generate::<Sha512, _>(&mut csprng); signatures.push(keypair.sign::<Sha512>(&messages[i])); keypairs.push(keypair); } let public_keys: Vec<PublicKey> = keypairs.iter().map(|key| key.public).collect(); let result = verify_batch::<Sha512>(&messages, &signatures[..], &public_keys[..]); assert!(result.is_ok()); } #[test] fn public_key_from_bytes() { // Make another function so that we can test the ? operator. 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, 014, 225, 114, 243, 218, 166, 035, 037, 175, 002, 026, 104, 247, 007, 081, 026, ]; let public_key = PublicKey::from_bytes(&public_key_bytes)?; Ok(public_key) } assert_eq!(do_the_test(), Ok(PublicKey(CompressedEdwardsY([ 215, 090, 152, 001, 130, 177, 010, 183, 213, 075, 254, 211, 201, 100, 007, 058, 014, 225, 114, 243, 218, 166, 035, 037, 175, 002, 026, 104, 247, 007, 081, 026, ])))) } #[test] fn keypair_clear_on_drop() { let mut keypair: Keypair = Keypair::from_bytes(&[15u8; KEYPAIR_LENGTH][..]).unwrap(); keypair.clear(); fn as_bytes<T>(x: &T) -> &[u8] { use core::mem; use core::slice; unsafe { slice::from_raw_parts(x as *const T as *const u8, mem::size_of_val(x)) } } assert!(!as_bytes(&keypair).contains(&0x15)); } #[test] fn pubkey_from_secret_and_expanded_secret() { let mut csprng = thread_rng(); let secret: SecretKey = SecretKey::generate::<_>(&mut csprng); let expanded_secret: ExpandedSecretKey = ExpandedSecretKey::from_secret_key::<Sha512>(&secret); let public_from_secret: PublicKey = PublicKey::from_secret::<Sha512>(&secret); let public_from_expanded_secret: PublicKey = PublicKey::from_expanded_secret(&expanded_secret); assert!(public_from_secret == public_from_expanded_secret); } #[cfg(all(test, feature = "serde"))] use bincode::{serialize, deserialize, Infinite}; #[cfg(all(test, feature = "serde"))] #[test] fn serialize_deserialize_signature() { let signature: Signature = Signature::from_bytes(&SIGNATURE_BYTES).unwrap(); let encoded_signature: Vec<u8> = serialize(&signature, Infinite).unwrap(); let decoded_signature: Signature = deserialize(&encoded_signature).unwrap(); assert_eq!(signature, decoded_signature); } #[cfg(all(test, feature = "serde"))] #[test] fn serialize_deserialize_public_key() { let encoded_public_key: Vec<u8> = serialize(&PUBLIC_KEY, Infinite).unwrap(); let decoded_public_key: PublicKey = deserialize(&encoded_public_key).unwrap(); assert_eq!(PUBLIC_KEY, decoded_public_key); } #[cfg(all(test, feature = "serde"))] #[test] fn serialize_deserialize_secret_key() { let encoded_secret_key: Vec<u8> = serialize(&SECRET_KEY, Infinite).unwrap(); let decoded_secret_key: SecretKey = deserialize(&encoded_secret_key).unwrap(); for i in 0..32 { assert_eq!(SECRET_KEY.0[i], decoded_secret_key.0[i]); } } }