refactor hmac key

apowers313 · Dec 11, 2021 · 8006175 · 8006175
1 parent a0d9e3a
commit 8006175
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Showing 4 changed files with 33 additions and 63 deletions.
diff --git a/src/comm/comm.test.ts b/src/comm/comm.test.ts
@@ -38,17 +38,20 @@ const ijavascriptMsg: Array<Uint8Array> = [
 
 Deno.test("message parsing", async () => {
     // const connFile = await Kernel.parseConnectionFile("./src/testdata/connfile.json");
-    console.log("");
+    const hmacKey = await window.crypto.subtle.importKey(
+        "raw",
+        new TextEncoder().encode(connFile.key),
+        { name: "HMAC", hash: { name: "SHA-256" } },
+        true,
+        ["sign", "verify"]
+    );
 
     const c = new Comm({
         name: "test",
         hostname: "127.0.0.1",
         port: 0,
         sessionId: "bob",
-        hmacKey: {
-            alg: "sha256",
-            key: connFile.key
-        },
+        hmacKey,
         handler: recvCb,
         type: "router"
     });

diff --git a/src/comm/comm.ts b/src/comm/comm.ts
@@ -12,10 +12,7 @@ export interface CommContext {
     sessionId: string;
 }
 
-export interface HmacKey {
-    alg: "sha256",
-    key: string;
-}
+export type HmacKey = CryptoKey;
 
 export interface CommCfg {
     name: string;

diff --git a/src/comm/message.ts b/src/comm/message.ts
@@ -181,15 +181,19 @@ export class Message {
     public async serialize(hmacKey: HmacKey): Promise<Uint8Array[]> {
         // format data
         const messages: Array<Uint8Array> = [];
+        const header = JSON.stringify(this.header);
+        const parentHeader = JSON.stringify(this.parentHeader);
+        const metadata = JSON.stringify(this.metadata);
+        const content = JSON.stringify(this.content);
+        const hmac = await this.hmacSign(hmacKey, header, parentHeader, metadata, content);
+
         messages.push(stringToAb("<IDS|MSG>"));
-        const hmac = await this.calcHmac(hmacKey);
-        // console.log("calculated HMAC:", hmac);
-        // console.log("calculated HMAC buf:", stringToAb(hmac).toString());
         messages.push(stringToAb(hmac));
-        messages.push(stringToAb(JSON.stringify(this.header)));
-        messages.push(stringToAb(JSON.stringify(this.parentHeader)));
-        messages.push(stringToAb(JSON.stringify(this.metadata)));
-        messages.push(stringToAb(JSON.stringify(this.content)));
+        messages.push(stringToAb(header));
+        messages.push(stringToAb(parentHeader));
+        messages.push(stringToAb(metadata));
+        messages.push(stringToAb(content));
+
         if (this.buffers) {
             console.error("Jupyter message buffers not currently supported");
         }
@@ -199,66 +203,29 @@ export class Message {
         return (messages as Uint8Array[]);
     }
 
-    public async calcHmac(hmacKey: HmacKey): Promise<string> {
-        const headerStr = JSON.stringify(this.header);
-        const parentHeaderStr = JSON.stringify(this.parentHeader);
-        const metadataStr = JSON.stringify(this.metadata);
-        const contentStr = JSON.stringify(this.content);
-
-        const hmacData = `${headerStr}${parentHeaderStr}${metadataStr}${contentStr}`;
-        console.log(`HMAC data: '${hmacData}'`);
-        const keyBuf = new TextEncoder().encode(hmacKey.key);
+    public async hmacSign(hmacKey: HmacKey, header: string, parentHeader: string, metadata: string, content: string): Promise<string> {
+        const hmacData = `${header}${parentHeader}${metadata}${content}`;
         const hmacBuf = new TextEncoder().encode(hmacData);
-        console.log("hmacBuf", hmacBuf.toString());
-        console.log("hmacData size", hmacData.length);
-        console.log("hmacBuf size", hmacBuf.buffer.byteLength);
-
-        // TODO: replace hmacKey with this key
-        const key = await window.crypto.subtle.importKey(
-            "raw",
-            keyBuf,
-            { name: "HMAC", hash: { name: "SHA-256" } },
-            true,
-            ["sign", "verify"]
-        );
-        const sig = await window.crypto.subtle.sign(
-            "HMAC",
-            key,
-            hmacBuf
-        );
-        const b = new Uint8Array(sig);
-        const ret2 = Array.prototype.map.call(b, x => ('00' + x.toString(16)).slice(-2)).join("");
+
+        const sig = await window.crypto.subtle.sign("HMAC", hmacKey, hmacBuf);
+        const ret2 = buf2hex(sig);
         console.log("++++ WEBCRYPTO HMAC", ret2);
 
         return ret2;
     }
 
-    public static async hmacSign() {
-
-    }
-
     public static async hmacVerify(expectedSig: Uint8Array, hmacKey: HmacKey, headerBuf: Uint8Array, parentHeaderBuf: Uint8Array, metadataBuf: Uint8Array, contentBuf: Uint8Array) {
-        const keyBuf = new TextEncoder().encode(hmacKey.key);
-
         const hmacBuf = Uint8Array.from([
             ...headerBuf,
             ...parentHeaderBuf,
             ...metadataBuf,
             ...contentBuf,
         ]);
 
-        const cryptoKey = await window.crypto.subtle.importKey(
-            "raw",
-            keyBuf,
-            { name: "HMAC", hash: { name: "SHA-256" } },
-            true,
-            ["sign", "verify"]
-        );
-
         const decodedSig = hexStringToArrayBuffer(new TextDecoder().decode(expectedSig));
         const valid = await window.crypto.subtle.verify(
             "HMAC",
-            cryptoKey,
+            hmacKey,
             decodedSig,
             hmacBuf
         );

diff --git a/src/kernel.ts b/src/kernel.ts
@@ -103,10 +103,13 @@ export class Kernel {
         console.info("initializing IDeno kernel...");
 
         this.connectionSpec = await Kernel.parseConnectionFile(this.connectionFile);
-        this.hmacKey = {
-            key: this.connectionSpec.key,
-            alg: "sha256"
-        };
+        this.hmacKey = await window.crypto.subtle.importKey(
+            "raw",
+            new TextEncoder().encode(this.connectionSpec.key),
+            { name: "HMAC", hash: { name: "SHA-256" } },
+            true,
+            ["sign", "verify"]
+        );
 
         this.addComm(ShellComm, this.connectionSpec.shell_port, this.shellHandler.bind(this));
         this.addComm(ControlComm, this.connectionSpec.control_port, this.controlHandler.bind(this));