From 4a9a1f3d4fa0ef9cd02df3ddfabc0ec6eede120d Mon Sep 17 00:00:00 2001
From: Tony Arcieri <bascule@gmail.com>
Date: Wed, 6 Mar 2024 17:14:15 -0700
Subject: [PATCH] ssh-key: correct erroneous signature constants

The elliptic curve was misspecified for `p384::ecdsa::Signature` and
`p521::ecdsa::Signature`.

Additionally P-521 had an incorrect field size.

Closes #197
---
 ssh-key/src/signature.rs | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/ssh-key/src/signature.rs b/ssh-key/src/signature.rs
index 2a1e498..c791978 100644
--- a/ssh-key/src/signature.rs
+++ b/ssh-key/src/signature.rs
@@ -560,7 +560,7 @@ impl TryFrom<&Signature> for p384::ecdsa::Signature {
 
         match signature.algorithm {
             Algorithm::Ecdsa {
-                curve: EcdsaCurve::NistP256,
+                curve: EcdsaCurve::NistP384,
             } => {
                 let reader = &mut signature.as_bytes();
                 let r = Mpint::decode(reader)?;
@@ -586,11 +586,11 @@ impl TryFrom<&Signature> for p521::ecdsa::Signature {
     type Error = Error;
 
     fn try_from(signature: &Signature) -> Result<p521::ecdsa::Signature> {
-        const FIELD_SIZE: usize = 48;
+        const FIELD_SIZE: usize = 66;
 
         match signature.algorithm {
             Algorithm::Ecdsa {
-                curve: EcdsaCurve::NistP256,
+                curve: EcdsaCurve::NistP521,
             } => {
                 let reader = &mut signature.as_bytes();
                 let r = Mpint::decode(reader)?;