fix(signatures): ensure crypto engine is always installed before use (#36)

Author: Mythie

src/integration/signatures/signing.test.ts

@@ -459,6 +459,8 @@ describe("signing integration", () => {
 
       const pdfStr = new TextDecoder().decode(bytes);
       expect(pdfStr).toContain("/Type /Sig");
+
+      await saveTestOutput("signatures/signed-aes128.pdf", bytes);
     });
 
     it("signs with Triple DES P12", async () => {
@@ -473,6 +475,8 @@ describe("signing integration", () => {
 
       const pdfStr = new TextDecoder().decode(bytes);
       expect(pdfStr).toContain("/Type /Sig");
+
+      await saveTestOutput("signatures/signed-3des.pdf", bytes);
     });
 
     it("signs with legacy RC2 P12", async () => {
@@ -487,6 +491,8 @@ describe("signing integration", () => {
 
       const pdfStr = new TextDecoder().decode(bytes);
       expect(pdfStr).toContain("/Type /Sig");
+
+      await saveTestOutput("signatures/signed-rc2.pdf", bytes);
     });
   });
 

src/signatures/crypto/crypto-engine.ts

@@ -245,12 +245,18 @@ export function getCryptoEngine(): CryptoEngine {
 }
 
 /**
- * Install the legacy crypto engine globally in pkijs.
- * Call this once at startup to enable legacy P12 support.
+ * Get the pkijs Crypto object, ensuring our custom engine is installed.
+ *
+ * Handles cases where pkijs engine might not be set yet, or where another
+ * engine is already installed.
  */
-export function installCryptoEngine(): void {
+export const getCrypto = () => {
   const engine = getCryptoEngine();
 
-  // oxlint-disable-next-line typescript/no-unsafe-type-assertion
-  pkijs.setEngine(engine.name, engine as unknown as pkijs.ICryptoEngine);
-}
+  if (!pkijs.engine || pkijs.engine.name !== engine.name) {
+    // oxlint-disable-next-line typescript/no-unsafe-type-assertion
+    pkijs.setEngine(engine.name, engine as unknown as pkijs.ICryptoEngine);
+  }
+
+  return pkijs.getCrypto(true);
+};

src/signatures/crypto/index.ts

@@ -10,7 +10,7 @@ export {
   CryptoEngine,
   decryptLegacyPbe,
   getCryptoEngine,
-  installCryptoEngine,
+  getCrypto,
   isLegacyPbeOid,
   LEGACY_PBE_OIDS,
 } from "./crypto-engine";

src/signatures/revocation.ts

@@ -12,6 +12,7 @@ import { fromBER, ObjectIdentifier, OctetString, Sequence } from "asn1js";
 import * as pkijs from "pkijs";
 
 import { toArrayBuffer } from "../helpers/buffer";
+import { getCrypto } from "./crypto";
 import {
   OID_AD_OCSP,
   OID_AUTHORITY_INFO_ACCESS,
@@ -245,7 +246,7 @@ export class DefaultRevocationProvider implements RevocationProvider {
     cert: pkijs.Certificate,
     issuer: pkijs.Certificate,
   ): Promise<Uint8Array> {
-    const crypto = pkijs.getCrypto(true);
+    const crypto = getCrypto();
 
     // Use SHA-1 for OCSP certID hashes.
     // While SHA-1 is deprecated for signatures, it's widely required for OCSP

src/signatures/signers/crypto-key.ts

@@ -4,13 +4,11 @@
  * Signs using a CryptoKey directly.
  */
 
-import * as pkijs from "pkijs";
 import { createCMSECDSASignature } from "pkijs";
 
+import { getCrypto } from "../crypto";
 import type { DigestAlgorithm, KeyType, SignatureAlgorithm, Signer } from "../types";
 
-const cryptoEngine = pkijs.getCrypto(true);
-
 /**
  * Signer that uses a Web Crypto CryptoKey directly.
  *
@@ -71,6 +69,8 @@ export class CryptoKeySigner implements Signer {
    * @returns Raw signature bytes
    */
   async sign(data: Uint8Array, algorithm: DigestAlgorithm): Promise<Uint8Array> {
+    const crypto = getCrypto();
+
     let signAlgorithm: { name: string; saltLength?: number; hash?: { name: string } };
 
     switch (this.signatureAlgorithm) {
@@ -87,7 +87,7 @@ export class CryptoKeySigner implements Signer {
         break;
     }
 
-    const signature = await cryptoEngine.sign(signAlgorithm, this.privateKey, new Uint8Array(data));
+    const signature = await crypto.sign(signAlgorithm, this.privateKey, new Uint8Array(data));
 
     // WebCrypto ECDSA returns P1363 format (r || s), but CMS requires DER format
     if (this.signatureAlgorithm === "ECDSA") {

src/signatures/signers/p12.ts

@@ -10,7 +10,7 @@ import { createCMSECDSASignature } from "pkijs";
 
 import { toArrayBuffer } from "../../helpers/buffer";
 import { buildCertificateChain } from "../aia";
-import { decryptLegacyPbe, installCryptoEngine, isLegacyPbeOid, PKCS12KDF } from "../crypto";
+import { decryptLegacyPbe, getCrypto, isLegacyPbeOid, PKCS12KDF } from "../crypto";
 import {
   OID_CERT_BAG,
   OID_EC_PUBLIC_KEY,
@@ -24,12 +24,6 @@ import {
 import type { DigestAlgorithm, KeyType, SignatureAlgorithm, Signer } from "../types";
 import { CertificateChainError, SignerError } from "../types";
 
-// Install our legacy crypto engine to handle 3DES/RC2 encrypted P12 files
-installCryptoEngine();
-
-// Get the crypto engine (now with legacy support)
-const cryptoEngine = pkijs.getCrypto(true);
-
 /**
  * Options for creating a P12Signer.
  */
@@ -252,6 +246,8 @@ export class P12Signer implements Signer {
     password: string,
     passwordBuffer: ArrayBuffer,
   ): Promise<CryptoKey> {
+    const crypto = getCrypto();
+
     // oxlint-disable-next-line typescript/no-unsafe-type-assertion
     const keyBag = safeBag.bagValue as pkijs.PKCS8ShroudedKeyBag;
     const algorithmId = keyBag.encryptionAlgorithm.algorithmId;
@@ -300,7 +296,7 @@ export class P12Signer implements Signer {
       decryptedKey = toArrayBuffer(decrypted);
     } else {
       // Use pkijs/Web Crypto
-      decryptedKey = await cryptoEngine.decryptEncryptedContentInfo({
+      decryptedKey = await crypto.decryptEncryptedContentInfo({
         encryptedContentInfo: new pkijs.EncryptedContentInfo({
           contentEncryptionAlgorithm: keyBag.encryptionAlgorithm,
           encryptedContent: keyBag.encryptedData,
@@ -325,11 +321,13 @@ export class P12Signer implements Signer {
    * Import a PrivateKeyInfo into WebCrypto.
    */
   private static async importPrivateKey(privateKeyInfo: pkijs.PrivateKeyInfo): Promise<CryptoKey> {
+    const crypto = getCrypto();
+
     const algorithmOid = privateKeyInfo.privateKeyAlgorithm.algorithmId;
 
     // RSA
     if (algorithmOid === OID_RSA_ENCRYPTION) {
-      return cryptoEngine.importKey(
+      return crypto.importKey(
         "pkcs8",
         privateKeyInfo.toSchema().toBER(false),
         { name: "RSASSA-PKCS1-v1_5", hash: "SHA-256" },
@@ -355,7 +353,7 @@ export class P12Signer implements Signer {
         }
       }
 
-      return cryptoEngine.importKey(
+      return crypto.importKey(
         "pkcs8",
         privateKeyInfo.toSchema().toBER(false),
         { name: "ECDSA", namedCurve },
@@ -413,6 +411,8 @@ export class P12Signer implements Signer {
    * @returns The signature bytes
    */
   async sign(data: Uint8Array, algorithm: DigestAlgorithm): Promise<Uint8Array> {
+    const crypto = getCrypto();
+
     let signAlgorithm: { name: string; saltLength?: number; hash?: { name: string } };
 
     switch (this.signatureAlgorithm) {
@@ -429,7 +429,7 @@ export class P12Signer implements Signer {
         break;
     }
 
-    const signature = await cryptoEngine.sign(signAlgorithm, this.privateKey, new Uint8Array(data));
+    const signature = await crypto.sign(signAlgorithm, this.privateKey, new Uint8Array(data));
 
     // WebCrypto ECDSA returns P1363 format (r || s), but CMS requires DER format
     if (this.signatureAlgorithm === "ECDSA") {