Slow PKCS #12 generation

[pboguslawski]

PKCS #12 generating with 600k iterations with code below (similar to openSSLLike example) takes 49-60s (tested in Firefox 115.9.1esr 64bit and Chromium 90 64-bit). Tested that most of the execution time is eaten by last makeInternalValues call (integrity protection envelope).

PKCS #12 generating with 600k iterations on same machine with openssl 3 from Debian 12 takes less than 1s:

$ time openssl pkcs12 -export -in test.crt -inkey test.key -out test.p12 -name 'test' -password pass:1234 -iter 600000

real	0m0.917s
user	0m0.894s
sys	0m0.000s

Is it expected or PKI.js bug?

PKCS #12 generation function code using PKI.js (PBKDF2_ITERATION_COUNT is set to 600000 during test):

// downloadPKCS12 downloads given private key and certificate in encrypted PKCS #12 file.
export async function downloadPKCS12(
	keyPair: CryptoKeyPair,
	certificate: Certificate,
	ownerId: string,
	password: string,
	filename: string
) {
	if (!password) {
		throw new Error('password cannot be empty');
	}
	if (!ownerId) {
		throw new Error('ownerId cannot be empty');
	}
	if (!filename) {
		throw new Error('filename cannot be empty');
	}

	const crypto = getCrypto(true);
	const passwordConverted = Convert.FromUtf8String(password);
	const certFingerprint = await crypto.digest('SHA-1', certificate.toSchema().toBER(false));
	const privateKeyBinary = await crypto.subtle.exportKey('pkcs8', keyPair.privateKey);
	const pkcs8Simpl = new PrivateKeyInfo({ schema: fromBER(privateKeyBinary).result });

	// Put initial values for PKCS#12 structures.
	const pkcs12 = new PFX({
		parsedValue: {
			integrityMode: 0, // Password-Based Integrity Mode.
			authenticatedSafe: new AuthenticatedSafe({
				parsedValue: {
					safeContents: [
						{
							privacyMode: 1, // Password-Based Privacy Protection Mode.
							value: new SafeContents({
								safeBags: [
									new SafeBag({
										bagId: '1.2.840.113549.1.12.10.1.3',
										bagValue: new CertBag({
											parsedValue: certificate
										}),
										bagAttributes: [
											new Attribute({
												type: '1.2.840.113549.1.9.21', // localKeyID
												values: [new OctetString({ valueHex: certFingerprint })]
											}),
											new Attribute({
												type: '1.2.840.113549.1.9.20', // friendlyName
												values: [new BmpString({ value: ownerId })]
											})
										]
									})
								]
							})
						},
						{
							privacyMode: 0, // No-privacy Protection Mode.
							value: new SafeContents({
								safeBags: [
									new SafeBag({
										bagId: '1.2.840.113549.1.12.10.1.2',
										bagValue: new PKCS8ShroudedKeyBag({
											parsedValue: pkcs8Simpl
										}),
										bagAttributes: [
											new Attribute({
												type: '1.2.840.113549.1.9.21', // localKeyID
												values: [new OctetString({ valueHex: certFingerprint })]
											}),
											new Attribute({
												type: '1.2.840.113549.1.9.20', // friendlyName
												values: [new BmpString({ value: ownerId })]
											})
										]
									})
								]
							})
						}
					]
				}
			})
		}
	});

	// Encode internal values for PKCS8ShroudedKeyBag.
	if (!(pkcs12.parsedValue && pkcs12.parsedValue.authenticatedSafe)) {
		throw new Error('pkcs12.parsedValue.authenticatedSafe is empty');
	}
	await pkcs12.parsedValue.authenticatedSafe.parsedValue.safeContents[1].value.safeBags[0].bagValue.makeInternalValues(
		{
			password: passwordConverted,
			contentEncryptionAlgorithm: {
				name: 'AES-CBC', // OpenSSL can handle AES-CBC only.
				length: 256
			},
			hmacHashAlgorithm: 'SHA-256',
			iterationCount: PBKDF2_ITERATION_COUNT
		}
	);

	// Encode internal values for all SafeContents first (create all Privacy Protection envelopes).
	await pkcs12.parsedValue.authenticatedSafe.makeInternalValues({
		safeContents: [
			{
				password: passwordConverted,
				contentEncryptionAlgorithm: {
					name: 'AES-CBC', // OpenSSL can handle AES-CBC only.
					length: 256
				},
				hmacHashAlgorithm: 'SHA-256',
				iterationCount: PBKDF2_ITERATION_COUNT
			},
			{
				// Empty parameters for second SafeContent since No Privacy protection mode there.
			}
		]
	});

	// Encode internal values for Integrity Protection envelope.
	await pkcs12.makeInternalValues({
		password: passwordConverted,
		iterations: PBKDF2_ITERATION_COUNT, // Big value here causes long generation time.
		pbkdf2HashAlgorithm: 'SHA-256', // Least two parameters are equal because at the moment it is not clear how to use PBMAC1 schema with PKCS#12 integrity protection.
		hmacHashAlgorithm: 'SHA-256'
	});

	// Download prepared PKCS #12 content to file.
	downloadFile(filename, 'application/pkcs12', pkcs12.toSchema().toBER(false));
}