From ef8532e89d0caf8156b822805b38c1f3953c1090 Mon Sep 17 00:00:00 2001
From: Daniel Huigens <d.huigens@protonmail.com>
Date: Fri, 20 Sep 2024 02:45:09 +0200
Subject: [PATCH 1/2] Fix P-521 bit length in Web Crypto

ECDH over P-521 returns 66 bytes, i.e. 528 bits. Requesting 521 bits
entails a truncation of the derived value, which seems unintended.
---
 packages/crypto/src/keys/ecdh/index.browser.ts | 18 ++++++------------
 1 file changed, 6 insertions(+), 12 deletions(-)

diff --git a/packages/crypto/src/keys/ecdh/index.browser.ts b/packages/crypto/src/keys/ecdh/index.browser.ts
index 63d3470673..4b880cf871 100644
--- a/packages/crypto/src/keys/ecdh/index.browser.ts
+++ b/packages/crypto/src/keys/ecdh/index.browser.ts
@@ -7,13 +7,13 @@ import webcrypto from '../../webcrypto/index.js'
 import type { Curve } from './index.js'
 import type { ECDHKey, ECDHKeyPair, JWKEncodedPrivateKey, JWKEncodedPublicKey } from '../interface.js'
 
-const bits = {
-  'P-256': 256,
-  'P-384': 384,
-  'P-521': 521
+const curveLengths = {
+  'P-256': 32,
+  'P-384': 48,
+  'P-521': 66
 }
 
-const curveTypes = Object.keys(bits)
+const curveTypes = Object.keys(curveLengths)
 const names = curveTypes.join(' / ')
 
 export async function generateEphemeralKeyPair (curve: Curve): Promise<ECDHKey> {
@@ -68,7 +68,7 @@ export async function generateEphemeralKeyPair (curve: Curve): Promise<ECDHKey>
         public: key
       },
       privateKey,
-      bits[curve]
+      curveLengths[curve] * 8
     )
 
     return new Uint8Array(buffer, 0, buffer.byteLength)
@@ -84,12 +84,6 @@ export async function generateEphemeralKeyPair (curve: Curve): Promise<ECDHKey>
   return ecdhKey
 }
 
-const curveLengths = {
-  'P-256': 32,
-  'P-384': 48,
-  'P-521': 66
-}
-
 // Marshal converts a jwk encoded ECDH public key into the
 // form specified in section 4.3.6 of ANSI X9.62. (This is the format
 // go-ipfs uses)

From 7353bf6ab4d9567f6fe477b4c476777847336632 Mon Sep 17 00:00:00 2001
From: Daniel Huigens <d.huigens@protonmail.com>
Date: Fri, 20 Sep 2024 02:47:43 +0200
Subject: [PATCH 2/2] Remove superfluous `namedCurve` property in deriveBits
 algorithm

---
 packages/crypto/src/keys/ecdh/index.browser.ts | 2 --
 1 file changed, 2 deletions(-)

diff --git a/packages/crypto/src/keys/ecdh/index.browser.ts b/packages/crypto/src/keys/ecdh/index.browser.ts
index 4b880cf871..742bd19a7b 100644
--- a/packages/crypto/src/keys/ecdh/index.browser.ts
+++ b/packages/crypto/src/keys/ecdh/index.browser.ts
@@ -63,8 +63,6 @@ export async function generateEphemeralKeyPair (curve: Curve): Promise<ECDHKey>
     const buffer = await webcrypto.get().subtle.deriveBits(
       {
         name: 'ECDH',
-        // @ts-expect-error namedCurve is missing from the types
-        namedCurve: curve,
         public: key
       },
       privateKey,