From 9fc3613cf5ea071d76cd24cb569a528914cddd36 Mon Sep 17 00:00:00 2001
From: Hatter Jiang <jht5945@gmail.com>
Date: Sat, 11 Jan 2025 16:46:35 +0800
Subject: [PATCH] feat: update deno-sshsig-mod.ts

---
 libraries/deno-sshsig-mod.ts | 48 ++++++++++++++++++++++++++++++------
 1 file changed, 41 insertions(+), 7 deletions(-)

diff --git a/libraries/deno-sshsig-mod.ts b/libraries/deno-sshsig-mod.ts
index b113530..35e50a9 100644
--- a/libraries/deno-sshsig-mod.ts
+++ b/libraries/deno-sshsig-mod.ts
@@ -1,7 +1,7 @@
 import {crypto} from "jsr:@std/crypto";
 import {decodeBase64} from "jsr:@std/encoding/base64";
 import {encodeBase64Url} from "jsr:@std/encoding/base64url";
-import {encodeHex} from "jsr:@std/encoding/hex";
+import {decodeHex, encodeHex} from "jsr:@std/encoding/hex";
 
 // Reference:
 // * https://github.com/openssh/openssh-portable/blob/master/PROTOCOL.sshsig
@@ -66,8 +66,8 @@ class BinaryWriter {
     }
 
     writeString(byte: Uint8Array) {
-        this._writeUint32(byte.byteLength);
-        this._writeBytes(byte);
+        this.writeUint32(byte.byteLength);
+        this.writeBytes(byte);
     }
 
     writeStringFromString(str: string) {
@@ -77,16 +77,22 @@ class BinaryWriter {
 
     writeLengthFromString(str: string) {
         const bytes = new TextEncoder().encode(str);
-        this._writeBytes(bytes);
+        this.writeBytes(bytes);
     }
 
-    _writeUint32(num: number) {
+    writeUint32(num: number) {
         let dataView = new DataView(new ArrayBuffer(4), 0);
         dataView.setUint32(0, num);
-        this._writeBytes(new Uint8Array(dataView.buffer));
+        this.writeBytes(new Uint8Array(dataView.buffer));
     }
 
-    _writeBytes(bytes: Uint8Array) {
+    writeNumber(num: number) {
+        let n = new Uint8Array(1)
+        n[0] = num;
+        this.writeBytes(n);
+    }
+
+    writeBytes(bytes: Uint8Array) {
         this.buffers.push(bytes);
     }
 }
@@ -203,6 +209,33 @@ class SshSignatureValue {
         const s = signatureEcReader.readString();
         return new SshSignatureValue(signatureAlgorithm, r, s);
     }
+
+    // SEQUENCE {
+    //   INTEGER: 00cdf3f5e083974961a9737daa2352cf08f7e652f103d4e3cc494b5ffadccf1a6d
+    //   INTEGER: 69658b75c9c7523c15e6de16907350f0d0fd51114237c3e32bdd9fe92465e768
+    // }
+    toDer(): Uint8Array {
+        let writer = new BinaryWriter();
+        writer.writeNumber(0x30);
+        writer.writeNumber(0x45);
+
+        writer.writeNumber(2);
+        const rFirstByte = this.ecSignatureR[0];
+        writer.writeNumber(((rFirstByte >= 0x80) ? 1 : 0) + this.ecSignatureR.byteLength);
+        if (rFirstByte >= 0x80) {
+            writer.writeNumber(0);
+        }
+        writer.writeBytes(this.ecSignatureR);
+
+        writer.writeNumber(2);
+        const sFirstByte = this.ecSignatureS[0];
+        writer.writeNumber(((sFirstByte >= 0x80) ? 1 : 0) + this.ecSignatureS.byteLength);
+        if (sFirstByte >= 0x80) {
+            writer.writeNumber(0);
+        }
+        writer.writeBytes(this.ecSignatureS);
+        return writer.merge();
+    }
 }
 
 class SshPublicKey {
@@ -331,6 +364,7 @@ console.log(encodeHex(sig));
 
 const publicKey = await sshSignature.publicKey.importJwk();
 console.log(publicKey);
+console.log(encodeHex(sshSignature.signature.toDer()));
 
 // crypto.subtle.verify(
 //     {