1 files changed, 252 insertions, 0 deletions
diff --git a/packages/backend/src/core/WebAuthnService.ts b/packages/backend/src/core/WebAuthnService.ts
new file mode 100644
index 0000000000..1c344eabe1
--- /dev/null
+++ b/packages/backend/src/core/WebAuthnService.ts
@@ -0,0 +1,252 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and other misskey contributors
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { Inject, Injectable } from '@nestjs/common';
+import * as Redis from 'ioredis';
+import {
+	generateAuthenticationOptions,
+	generateRegistrationOptions, verifyAuthenticationResponse,
+	verifyRegistrationResponse,
+} from '@simplewebauthn/server';
+import { AttestationFormat, isoCBOR } from '@simplewebauthn/server/helpers';
+import { DI } from '@/di-symbols.js';
+import type { UserSecurityKeysRepository } from '@/models/index.js';
+import type { Config } from '@/config.js';
+import { bindThis } from '@/decorators.js';
+import { MetaService } from '@/core/MetaService.js';
+import { MiUser } from '@/models/index.js';
+import { IdentifiableError } from '@/misc/identifiable-error.js';
+import type {
+	AuthenticationResponseJSON,
+	AuthenticatorTransportFuture,
+	CredentialDeviceType,
+	PublicKeyCredentialCreationOptionsJSON,
+	PublicKeyCredentialDescriptorFuture,
+	PublicKeyCredentialRequestOptionsJSON,
+	RegistrationResponseJSON,
+} from '@simplewebauthn/typescript-types';
+
+@Injectable()
+export class WebAuthnService {
+	constructor(
+		@Inject(DI.redis)
+		private redisClient: Redis.Redis,
+
+		@Inject(DI.config)
+		private config: Config,
+
+		@Inject(DI.userSecurityKeysRepository)
+		private userSecurityKeysRepository: UserSecurityKeysRepository,
+
+		private metaService: MetaService,
+	) {
+	}
+
+	@bindThis
+	public async getRelyingParty(): Promise<{ origin: string; rpId: string; rpName: string; rpIcon?: string; }> {
+		const instance = await this.metaService.fetch();
+		return {
+			origin: this.config.url,
+			rpId: this.config.host,
+			rpName: instance.name ?? this.config.host,
+			rpIcon: instance.iconUrl ?? undefined,
+		};
+	}
+
+	@bindThis
+	public async initiateRegistration(userId: MiUser['id'], userName: string, userDisplayName?: string): Promise<PublicKeyCredentialCreationOptionsJSON> {
+		const relyingParty = await this.getRelyingParty();
+		const keys = await this.userSecurityKeysRepository.findBy({
+			userId: userId,
+		});
+
+		const registrationOptions = await generateRegistrationOptions({
+			rpName: relyingParty.rpName,
+			rpID: relyingParty.rpId,
+			userID: userId,
+			userName: userName,
+			userDisplayName: userDisplayName,
+			attestationType: 'indirect',
+			excludeCredentials: keys.map(key => (<PublicKeyCredentialDescriptorFuture>{
+				id: Buffer.from(key.id, 'base64url'),
+				type: 'public-key',
+				transports: key.transports ?? undefined,
+			})),
+			authenticatorSelection: {
+				residentKey: 'required',
+				userVerification: 'preferred',
+			},
+		});
+
+		await this.redisClient.setex(`webauthn:challenge:${userId}`, 90, registrationOptions.challenge);
+
+		return registrationOptions;
+	}
+
+	@bindThis
+	public async verifyRegistration(userId: MiUser['id'], response: RegistrationResponseJSON): Promise<{
+		credentialID: Uint8Array;
+		credentialPublicKey: Uint8Array;
+		attestationObject: Uint8Array;
+		fmt: AttestationFormat;
+		counter: number;
+		userVerified: boolean;
+		credentialDeviceType: CredentialDeviceType;
+		credentialBackedUp: boolean;
+		transports?: AuthenticatorTransportFuture[];
+	}> {
+		const challenge = await this.redisClient.get(`webauthn:challenge:${userId}`);
+
+		if (!challenge) {
+			throw new IdentifiableError('7dbfb66c-9216-4e2b-9c27-cef2ac8efb84', 'challenge not found');
+		}
+
+		await this.redisClient.del(`webauthn:challenge:${userId}`);
+
+		const relyingParty = await this.getRelyingParty();
+
+		let verification;
+		try {
+			verification = await verifyRegistrationResponse({
+				response: response,
+				expectedChallenge: challenge,
+				expectedOrigin: relyingParty.origin,
+				expectedRPID: relyingParty.rpId,
+				requireUserVerification: true,
+			});
+		} catch (error) {
+			console.error(error);
+			throw new IdentifiableError('5c1446f8-8ca7-4d31-9f39-656afe9c5d87', 'verification failed');
+		}
+
+		const { verified } = verification;
+
+		if (!verified || !verification.registrationInfo) {
+			throw new IdentifiableError('bb333667-3832-4a80-8bb5-c505be7d710d', 'verification failed');
+		}
+
+		const { registrationInfo } = verification;
+
+		return {
+			credentialID: registrationInfo.credentialID,
+			credentialPublicKey: registrationInfo.credentialPublicKey,
+			attestationObject: registrationInfo.attestationObject,
+			fmt: registrationInfo.fmt,
+			counter: registrationInfo.counter,
+			userVerified: registrationInfo.userVerified,
+			credentialDeviceType: registrationInfo.credentialDeviceType,
+			credentialBackedUp: registrationInfo.credentialBackedUp,
+			transports: response.response.transports,
+		};
+	}
+
+	@bindThis
+	public async initiateAuthentication(userId: MiUser['id']): Promise<PublicKeyCredentialRequestOptionsJSON> {
+		const keys = await this.userSecurityKeysRepository.findBy({
+			userId: userId,
+		});
+
+		if (keys.length === 0) {
+			throw new IdentifiableError('f27fd449-9af4-4841-9249-1f989b9fa4a4', 'no keys found');
+		}
+
+		const authenticationOptions = await generateAuthenticationOptions({
+			allowCredentials: keys.map(key => (<PublicKeyCredentialDescriptorFuture>{
+				id: Buffer.from(key.id, 'base64url'),
+				type: 'public-key',
+				transports: key.transports ?? undefined,
+			})),
+			userVerification: 'preferred',
+		});
+
+		await this.redisClient.setex(`webauthn:challenge:${userId}`, 90, authenticationOptions.challenge);
+
+		return authenticationOptions;
+	}
+
+	@bindThis
+	public async verifyAuthentication(userId: MiUser['id'], response: AuthenticationResponseJSON): Promise<boolean> {
+		const challenge = await this.redisClient.get(`webauthn:challenge:${userId}`);
+
+		if (!challenge) {
+			throw new IdentifiableError('2d16e51c-007b-4edd-afd2-f7dd02c947f6', 'challenge not found');
+		}
+
+		await this.redisClient.del(`webauthn:challenge:${userId}`);
+
+		const key = await this.userSecurityKeysRepository.findOneBy({
+			id: response.id,
+			userId: userId,
+		});
+
+		if (!key) {
+			throw new IdentifiableError('36b96a7d-b547-412d-aeed-2d611cdc8cdc', 'unknown key');
+		}
+
+		// マイグレーション
+		if (key.counter === 0 && key.publicKey.length === 87) {
+			const cert = new Uint8Array(Buffer.from(key.publicKey, 'base64url'));
+			if (cert[0] === 0x04) { // 前の実装ではいつも 0x04 で始まっていた
+				const halfLength = (cert.length - 1) / 2;
+
+				const cborMap = new Map<number, number | ArrayBufferLike>();
+				cborMap.set(1, 2); // kty, EC2
+				cborMap.set(3, -7); // alg, ES256
+				cborMap.set(-1, 1); // crv, P256
+				cborMap.set(-2, cert.slice(1, halfLength + 1)); // x
+				cborMap.set(-3, cert.slice(halfLength + 1)); // y
+
+				const cborPubKey = Buffer.from(isoCBOR.encode(cborMap)).toString('base64url');
+				await this.userSecurityKeysRepository.update({
+					id: response.id,
+					userId: userId,
+				}, {
+					publicKey: cborPubKey,
+				});
+				key.publicKey = cborPubKey;
+			}
+		}
+
+		const relyingParty = await this.getRelyingParty();
+
+		let verification;
+		try {
+			verification = await verifyAuthenticationResponse({
+				response: response,
+				expectedChallenge: challenge,
+				expectedOrigin: relyingParty.origin,
+				expectedRPID: relyingParty.rpId,
+				authenticator: {
+					credentialID: Buffer.from(key.id, 'base64url'),
+					credentialPublicKey: Buffer.from(key.publicKey, 'base64url'),
+					counter: key.counter,
+					transports: key.transports ? key.transports as AuthenticatorTransportFuture[] : undefined,
+				},
+				requireUserVerification: true,
+			});
+		} catch (error) {
+			console.error(error);
+			throw new IdentifiableError('b18c89a7-5b5e-4cec-bb5b-0419f332d430', 'verification failed');
+		}
+
+		const { verified, authenticationInfo } = verification;
+
+		if (!verified) {
+			return false;
+		}
+
+		await this.userSecurityKeysRepository.update({
+			id: response.id,
+			userId: userId,
+		}, {
+			lastUsed: new Date(),
+			counter: authenticationInfo.newCounter,
+			credentialDeviceType: authenticationInfo.credentialDeviceType,
+			credentialBackedUp: authenticationInfo.credentialBackedUp,
+		});
+
+		return verified;
+	}
+}