AccountSASAuthenticator.ts

import IAccountDataStore from "../../common/IAccountDataStore";
import ILogger from "../../common/ILogger";
import StorageErrorFactory from "../errors/StorageErrorFactory";
import Operation from "../generated/artifacts/operation";
import Context from "../generated/Context";
import IRequest from "../generated/IRequest";
import {
  generateAccountSASSignature,
  IAccountSASSignatureValues
} from "../../common/authentication/IAccountSASSignatureValues";
import IAuthenticator from "./IAuthenticator";
import OPERATION_ACCOUNT_SAS_PERMISSIONS from "./OperationAccountSASPermission";

export default class AccountSASAuthenticator implements IAuthenticator {
  public constructor(
    private readonly accountDataStore: IAccountDataStore,
    private readonly logger: ILogger
  ) {}

  public async validate(
    req: IRequest,
    context: Context
  ): Promise<boolean | undefined> {
    this.logger.info(
      `AccountSASAuthenticator:validate() Start validation against account Shared Access Signature pattern.`,
      context.contextID
    );

    this.logger.debug(
      "AccountSASAuthenticator:validate() Getting account properties...",
      context.contextID
    );

    const account: string = context.context.account;
    const tableName: string | undefined = context.context.table;
    this.logger.debug(
      // tslint:disable-next-line:max-line-length
      `AccountSASAuthenticator:validate() Retrieved account name from context: ${account}, table: ${tableName}`,
      context.contextID
    );

    // TODO: Make following async
    const accountProperties = this.accountDataStore.getAccount(account);
    if (accountProperties === undefined) {
      throw StorageErrorFactory.ResourceNotFound(
        context
      );
    }
    this.logger.debug(
      "AccountSASAuthenticator:validate() Got account properties successfully.",
      context.contextID
    );

    const signature = this.decodeIfExist(req.getQuery("sig"));
    this.logger.debug(
      `AccountSASAuthenticator:validate() Retrieved signature from URL parameter sig: ${signature}`,
      context.contextID
    );

    const values = this.getAccountSASSignatureValuesFromRequest(req);
    if (values === undefined) {
      this.logger.info(
        `AccountSASAuthenticator:validate() Failed to get valid account SAS values from request.`,
        context.contextID
      );
      return false;
    }
    this.logger.debug(
      `AccountSASAuthenticator:validate() Successfully got valid account SAS values from request. ${JSON.stringify(
        values
      )}`,
      context.contextID
    );

    this.logger.info(
      `AccountSASAuthenticator:validate() Validate signature based account key1.`,
      context.contextID
    );
    const [sig1, stringToSign1] = generateAccountSASSignature(
      values,
      account,
      accountProperties.key1
    );
    this.logger.debug(
      `AccountSASAuthenticator:validate() String to sign is: ${JSON.stringify(
        stringToSign1
      )}`,
      context.contextID!
    );
    this.logger.debug(
      `AccountSASAuthenticator:validate() Calculated signature is: ${sig1}`,
      context.contextID!
    );

    const sig1Pass = sig1 === signature;
    this.logger.info(
      `AccountSASAuthenticator:validate() Signature based on key1 validation ${
        sig1Pass ? "passed" : "failed"
      }.`,
      context.contextID
    );

    if (!sig1Pass) {
      if (accountProperties.key2 === undefined) {
        return false;
      }

      this.logger.info(
        `AccountSASAuthenticator:validate() Account key2 is not empty, validate signature based account key2.`,
        context.contextID
      );
      const [sig2, stringToSign2] = generateAccountSASSignature(
        values,
        account,
        accountProperties.key2
      );
      this.logger.debug(
        `AccountSASAuthenticator:validate() String to sign is: ${JSON.stringify(
          stringToSign2
        )}`,
        context.contextID!
      );
      this.logger.debug(
        `AccountSASAuthenticator:validate() Calculated signature is: ${sig2}`,
        context.contextID!
      );

      const sig2Pass = sig2 === signature;
      this.logger.info(
        `AccountSASAuthenticator:validate() Signature based on key2 validation ${
          sig2Pass ? "passed" : "failed"
        }.`,
        context.contextID
      );

      if (!sig2Pass) {
        this.logger.info(
          `AccountSASAuthenticator:validate() Validate signature based account key1 and key2 failed.`,
          context.contextID
        );
        return false;
      }
    }

    // When signature validation passes, we enforce account SAS validation
    // Any validation errors will stop this request immediately

    this.logger.info(
      `AccountSASAuthenticator:validate() Validate start and expiry time.`,
      context.contextID
    );
    if (!this.validateTime(values.expiryTime, values.startTime)) {
      this.logger.info(
        `AccountSASAuthenticator:validate() Validate start and expiry failed.`,
        context.contextID
      );
      throw StorageErrorFactory.getAuthorizationFailure(context);
    }

    this.logger.info(
      `AccountSASAuthenticator:validate() Validate IP range.`,
      context.contextID
    );
    if (!this.validateIPRange()) {
      this.logger.info(
        `AccountSASAuthenticator:validate() Validate IP range failed.`,
        context.contextID
      );
      throw StorageErrorFactory.getAuthorizationSourceIPMismatch(context);
    }

    this.logger.info(
      `AccountSASAuthenticator:validate() Validate request protocol.`,
      context.contextID
    );
    if (!this.validateProtocol(values.protocol, req.getProtocol())) {
      this.logger.info(
        `AccountSASAuthenticator:validate() Validate protocol failed.`,
        context.contextID
      );
      throw StorageErrorFactory.getAuthorizationProtocolMismatch(context);
    }

    const operation = context.operation;
    if (operation === undefined) {
      throw new Error(
        // tslint:disable-next-line:max-line-length
        `AccountSASAuthenticator:validate() operation shouldn't be undefined. Please make sure DispatchMiddleware is hooked before authentication related middleware.`
      );
    }

    const accountSASPermission = OPERATION_ACCOUNT_SAS_PERMISSIONS.get(
      operation
    );
    this.logger.debug(
      `AccountSASAuthenticator:validate() Got permission requirements for operation ${
        Operation[operation]
      } - ${JSON.stringify(accountSASPermission)}`,
      context.contextID
    );
    if (accountSASPermission === undefined) {
      throw new Error(
        // tslint:disable-next-line:max-line-length
        `AccountSASAuthenticator:validate() OPERATION_ACCOUNT_SAS_PERMISSIONS doesn't have configuration for operation ${Operation[operation]}'s account SAS permission.`
      );
    }

    if (!accountSASPermission.validateServices(values.services)) {
      throw StorageErrorFactory.getAuthorizationServiceMismatch(context);
    }

    if (!accountSASPermission.validateResourceTypes(values.resourceTypes)) {
      throw StorageErrorFactory.getAuthorizationResourceTypeMismatch(context);
    }

    if (!accountSASPermission.validatePermissions(values.permissions)) {
      throw StorageErrorFactory.getAuthorizationPermissionMismatch(context);
    }

    this.logger.info(
      `AccountSASAuthenticator:validate() Account SAS validation successfully.`,
      context.contextID
    );

    return true;
  }

  private getAccountSASSignatureValuesFromRequest(
    req: IRequest
  ): IAccountSASSignatureValues | undefined {
    const version = this.decodeIfExist(req.getQuery("sv"));
    const services = this.decodeIfExist(req.getQuery("ss"));
    const resourceTypes = this.decodeIfExist(req.getQuery("srt"));
    const protocol = this.decodeIfExist(req.getQuery("spr"));
    const startTime = this.decodeIfExist(req.getQuery("st"));
    const expiryTime = this.decodeIfExist(req.getQuery("se"));
    const ipRange = this.decodeIfExist(req.getQuery("sip"));
    const permissions = this.decodeIfExist(req.getQuery("sp"));
    const signature = this.decodeIfExist(req.getQuery("sig"));

    if (
      version === undefined ||
      expiryTime === undefined ||
      permissions === undefined ||
      services === undefined ||
      resourceTypes === undefined ||
      signature === undefined
    ) {
      return undefined;
    }

    const accountSASValues: IAccountSASSignatureValues = {
      version,
      protocol,
      startTime,
      expiryTime,
      permissions,
      ipRange,
      services,
      resourceTypes
    };

    return accountSASValues;
  }

  private validateTime(expiry: Date | string, start?: Date | string): boolean {
    const expiryTime = new Date(expiry);
    const now = new Date();

    if (now > expiryTime) {
      return false;
    }

    if (start !== undefined) {
      const startTime = new Date(start);
      if (now < startTime) {
        return false;
      }
    }

    return true;
  }

  private validateIPRange(): boolean {
    // TODO: Emulator doesn't validate IP Address
    return true;
  }

  private validateProtocol(
    sasProtocol: string = "https,http",
    requestProtocol: string
  ): boolean {
    if (sasProtocol.includes(",")) {
      return true;
    } else {
      return sasProtocol.toLowerCase() === requestProtocol;
    }
  }

  private decodeIfExist(value?: string): string | undefined {
    return value === undefined ? value : decodeURIComponent(value);
  }
}