Struct akd::ecvrf::VRFPublicKey
source · pub struct VRFPublicKey(_);
Expand description
An ECVRF public key
Implementations§
source§impl VRFPublicKey
impl VRFPublicKey
sourcepub fn verify(&self, proof: &Proof, alpha: &[u8]) -> Result<(), VrfError>
pub fn verify(&self, proof: &Proof, alpha: &[u8]) -> Result<(), VrfError>
Given a Proof
and an input, returns whether or not the proof is valid for the input
and public key
sourcepub fn verify_label(
&self,
uname: &AkdLabel,
stale: bool,
version: u64,
proof: &[u8],
label: NodeLabel
) -> Result<(), VrfError>
pub fn verify_label(
&self,
uname: &AkdLabel,
stale: bool,
version: u64,
proof: &[u8],
label: NodeLabel
) -> Result<(), VrfError>
This function is called to verify that a given NodeLabel is indeed the VRF for a given version (fresh or stale) for a username. Hence, it also takes as input the server’s public key.
Methods from Deref<Target = PublicKey>§
sourcepub fn verify_prehashed<D>(
&self,
prehashed_message: D,
context: Option<&[u8]>,
signature: &Signature
) -> Result<(), Error>where
D: Digest<OutputSize = UInt<UInt<UInt<UInt<UInt<UInt<UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>>,
pub fn verify_prehashed<D>(
&self,
prehashed_message: D,
context: Option<&[u8]>,
signature: &Signature
) -> Result<(), Error>where
D: Digest<OutputSize = UInt<UInt<UInt<UInt<UInt<UInt<UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>>,
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 theprehashed_message
.
Returns
Returns true
if the signature
was a valid signature created by this
Keypair
on the prehashed_message
.
sourcepub fn verify_strict(
&self,
message: &[u8],
signature: &Signature
) -> Result<(), Error>
pub fn verify_strict(
&self,
message: &[u8],
signature: &Signature
) -> Result<(), Error>
Strictly verify a signature on a message with this keypair’s public key.
On The (Multiple) Sources of Malleability in Ed25519 Signatures
This version of verification is technically non-RFC8032 compliant. The following explains why.
- Scalar Malleability
The authors of the RFC explicitly stated that verification of an ed25519
signature must fail if the scalar s
is not properly reduced mod \ell:
To verify a signature on a message M using public key A, with F being 0 for Ed25519ctx, 1 for Ed25519ph, and if Ed25519ctx or Ed25519ph is being used, C being the context, first split the signature into two 32-octet halves. Decode the first half as a point R, and the second half as an integer S, in the range 0 <= s < L. Decode the public key A as point A’. If any of the decodings fail (including S being out of range), the signature is invalid.)
All verify_*()
functions within ed25519-dalek perform this check.
- Point malleability
The authors of the RFC added in a malleability check to step #3 in
§5.1.7, for small torsion components in the R
value of the signature,
which is not strictly required, as they state:
Check the group equation [8][S]B = [8]R + [8][k]A’. It’s sufficient, but not required, to instead check [S]B = R + [k]A’.
History of Malleability Checks
As originally defined (cf. the “Malleability” section in the README of this repo), ed25519 signatures didn’t consider any form of malleability to be an issue. Later the scalar malleability was considered important. Still later, particularly with interests in cryptocurrency design and in unique identities (e.g. for Signal users, Tor onion services, etc.), the group element malleability became a concern.
However, libraries had already been created to conform to the original definition. One well-used library in particular even implemented the group element malleability check, but only for batch verification! Which meant that even using the same library, a single signature could verify fine individually, but suddenly, when verifying it with a bunch of other signatures, the whole batch would fail!
“Strict” Verification
This method performs both of the above signature malleability checks.
It must be done as a separate method because one doesn’t simply get to change the definition of a cryptographic primitive ten years after-the-fact with zero consideration for backwards compatibility in hardware and protocols which have it already have the older definition baked in.
Return
Returns Ok(())
if the signature is valid, and Err
otherwise.
Trait Implementations§
source§impl Clone for VRFPublicKey
impl Clone for VRFPublicKey
source§fn clone(&self) -> VRFPublicKey
fn clone(&self) -> VRFPublicKey
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for VRFPublicKey
impl Debug for VRFPublicKey
source§impl Deref for VRFPublicKey
impl Deref for VRFPublicKey
source§impl<'de> Deserialize<'de> for VRFPublicKey
impl<'de> Deserialize<'de> for VRFPublicKey
source§fn deserialize<__D>(
__deserializer: __D
) -> Result<VRFPublicKey, <__D as Deserializer<'de>>::Error>where
__D: Deserializer<'de>,
fn deserialize<__D>(
__deserializer: __D
) -> Result<VRFPublicKey, <__D as Deserializer<'de>>::Error>where
__D: Deserializer<'de>,
source§impl<'a> From<&'a VRFPrivateKey> for VRFPublicKey
impl<'a> From<&'a VRFPrivateKey> for VRFPublicKey
source§fn from(private_key: &'a VRFPrivateKey) -> VRFPublicKey
fn from(private_key: &'a VRFPrivateKey) -> VRFPublicKey
source§impl PartialEq<VRFPublicKey> for VRFPublicKey
impl PartialEq<VRFPublicKey> for VRFPublicKey
source§fn eq(&self, other: &VRFPublicKey) -> bool
fn eq(&self, other: &VRFPublicKey) -> bool
source§impl Serialize for VRFPublicKey
impl Serialize for VRFPublicKey
source§fn serialize<__S>(
&self,
__serializer: __S
) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>where
__S: Serializer,
fn serialize<__S>(
&self,
__serializer: __S
) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>where
__S: Serializer,
source§impl TryFrom<&[u8]> for VRFPublicKey
impl TryFrom<&[u8]> for VRFPublicKey
impl Eq for VRFPublicKey
impl StructuralEq for VRFPublicKey
impl StructuralPartialEq for VRFPublicKey
Auto Trait Implementations§
impl RefUnwindSafe for VRFPublicKey
impl Send for VRFPublicKey
impl Sync for VRFPublicKey
impl Unpin for VRFPublicKey
impl UnwindSafe for VRFPublicKey
Blanket Implementations§
source§impl<Q, K> Equivalent<K> for Qwhere
Q: Eq + ?Sized,
K: Borrow<Q> + ?Sized,
impl<Q, K> Equivalent<K> for Qwhere
Q: Eq + ?Sized,
K: Borrow<Q> + ?Sized,
source§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
key
and return true
if they are equal.