Initial release

[websub-hub] / src / authenticator.js

diff --git a/src/authenticator.js b/src/authenticator.js
new file mode 100644 (file)
index 0000000..ed4fc40
--- /dev/null
+++ b/src/authenticator.js
@@ -0,0 +1,113 @@
+'use strict';
+
+const argon2 = require('argon2');
+const common = require('./common');
+const Enum = require('./enum');
+const Errors = require('./errors');
+
+const _fileScope = common.fileScope(__filename);
+
+class Authenticator {
+  constructor(logger, db, options) {
+    this.logger = logger;
+    this.db = db;
+    this.basicRealm = options.authenticator.basicRealm;
+    this.secureAuthOnly = options.authenticator.secureAuthOnly;
+  }
+
+
+  /**
+   * Check for valid Basic auth, updates ctx with identifier if valid.
+   * @param {String} credentials
+   * @param {Object} ctx
+   * @returns {Boolean}
+   */
+  async isValidBasic(credentials, ctx) {
+    const _scope = _fileScope('isValidBasic');
+    this.logger.debug(_scope, 'called', { ctx });
+
+    const [identifier, credential] = common.splitFirst(credentials, ':', '');
+
+    let valid = false;
+    await this.db.context(async (dbCtx) => {
+      const authData = await this.db.authenticationGet(dbCtx, identifier);
+      if (!authData) {
+        this.logger.debug(_scope, 'failed, invalid authentication id', { ctx });
+        return false;
+      }
+
+      if (authData.credential.startsWith('$argon2')) {
+        valid = await argon2.verify(authData.credential, credential);
+      } else {
+        this.logger.error(_scope, 'failed, unknown type of stored password hash', { ctx });
+      }
+      if (valid) {
+        ctx.authenticationId = identifier;
+        await this.db.authenticationSuccess(dbCtx, identifier);
+      }
+    });
+
+    return valid;
+  }
+
+
+  /**
+   * Determine which Authorization header is available, and if it is valid.
+   * @param {String} authorizationHeader
+   * @param {Object} ctx
+   */
+  async isValidAuthorization(authorizationHeader, ctx) {
+    const _scope = _fileScope('isValidAuthorization');
+    this.logger.debug(_scope, 'called', { authorizationHeader, ctx });
+
+    const [authMethod, authString] = common.splitFirst(authorizationHeader, ' ', '').map((x) => x.trim());
+    // eslint-disable-next-line sonarjs/no-small-switch
+    switch (authMethod.toLowerCase()) {
+      case 'basic': {
+        const credentials = Buffer.from(authString, 'base64').toString('utf-8');
+        return await this.isValidBasic(credentials, ctx);
+      }
+
+      default:
+        this.logger.debug(_scope, 'unknown authorization scheme', { ctx });
+        return false;
+    }
+  }
+
+
+  /**
+   * Send a response requesting basic auth.
+   * @param {http.ServerResponse} res
+   */
+  requestBasic(res) {
+    res.setHeader(Enum.Header.WWWAuthenticate, `Basic realm="${this.basicRealm}", charset="UTF-8"`);
+    throw new Errors.ResponseError(Enum.ErrorResponse.Unauthorized);
+  }
+
+
+  /**
+   * Require that a request has valid auth over secure channel, requests if missing.
+   * @param {http.ClientRequest} req
+   * @param {http.ServerResponse} res
+   * @param {Object} ctx
+   */
+  async required(req, res, ctx) {
+    const _scope = _fileScope('required');
+    this.logger.debug(_scope, 'called', { ctx });
+
+    if (this.secureAuthOnly && ctx.clientProtocol.toLowerCase() !== 'https') {
+      this.logger.debug(_scope, 'rejecting insecure auth', ctx);
+      throw new Errors.ResponseError(Enum.ErrorResponse.Forbidden, 'authentication required, but connection is insecure; cannot continue');
+    }
+
+    const authData = req.getHeader(Enum.Header.Authorization);
+    if (authData
+    &&  await this.isValidAuthorization(authData, ctx)) {
+        return true;
+    }
+    return this.requestBasic(res);
+  }
+
+}
+
+module.exports = Authenticator;
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