Add support for generic OAuth2 providers

Signed-off-by: Pedro Ferreira <pedro.ferreira@cern.ch>

6 files changed, 129 insertions, 0 deletions

diff --git a/lib/config/default.js b/lib/config/default.js
index 19ddccf6..48916c89 100644
--- a/lib/config/default.js
+++ b/lib/config/default.js
@@ -72,6 +72,12 @@ module.exports = {
   },
   s3bucket: undefined,
   // authentication
+  oauth2: {
+    authorizationURL: undefined,
+    tokenURL: undefined,
+    clientID: undefined,
+    clientSecret: undefined
+  },
   facebook: {
     clientID: undefined,
     clientSecret: undefined
diff --git a/lib/config/environment.js b/lib/config/environment.js
index cab3bc3e..66fa5284 100644
--- a/lib/config/environment.js
+++ b/lib/config/environment.js
@@ -66,6 +66,17 @@ module.exports = {
     clientID: process.env.HMD_MATTERMOST_CLIENTID,
     clientSecret: process.env.HMD_MATTERMOST_CLIENTSECRET
   },
+  oauth2: {
+    baseURL: process.env.HMD_OAUTH2_BASEURL,
+    userProfileURL: process.env.HMD_OAUTH2_USER_PROFILE_URL,
+    userProfileUsernameAttr: process.env.HMD_OAUTH2_USER_PROFILE_USERNAME_ATTR,
+    userProfileDisplayNameAttr: process.env.HMD_OAUTH2_USER_PROFILE_DISPLAY_NAME_ATTR,
+    userProfileEmailAttr: process.env.HMD_OAUTH2_USER_PROFILE_EMAIL_ATTR,
+    tokenURL: process.env.HMD_OAUTH2_TOKEN_URL,
+    authorizationURL: process.env.HMD_OAUTH2_AUTHORIZATION_URL,
+    clientID: process.env.HMD_OAUTH2_CLIENT_ID,
+    clientSecret: process.env.HMD_OAUTH2_CLIENT_SECRET
+  },
   dropbox: {
     clientID: process.env.HMD_DROPBOX_CLIENTID,
     clientSecret: process.env.HMD_DROPBOX_CLIENTSECRET,
diff --git a/lib/config/index.js b/lib/config/index.js
index fae51e52..63c23f0c 100644
--- a/lib/config/index.js
+++ b/lib/config/index.js
@@ -98,6 +98,7 @@ config.isGitLabEnable = config.gitlab.clientID && config.gitlab.clientSecret
 config.isMattermostEnable = config.mattermost.clientID && config.mattermost.clientSecret
 config.isLDAPEnable = config.ldap.url
 config.isSAMLEnable = config.saml.idpSsoUrl
+config.isOAuth2Enable = config.oauth2.clientID && config.oauth2.clientSecret
 config.isPDFExportEnable = config.allowPDFExport
 
 // merge legacy values
diff --git a/lib/response.js b/lib/response.js
index b18fd7a3..8dc1ed35 100644
--- a/lib/response.js
+++ b/lib/response.js
@@ -70,6 +70,8 @@ function showIndex (req, res, next) {
     ldap: config.isLDAPEnable,
     ldapProviderName: config.ldap.providerName,
     saml: config.isSAMLEnable,
+    oauth2: config.isOAuth2Enable,
+    oauth2ProviderName: config.oauth2.providerName,
     email: config.isEmailEnable,
     allowEmailRegister: config.allowEmailRegister,
     allowPDFExport: config.allowPDFExport,
@@ -104,7 +106,9 @@ function responseHackMD (res, note) {
     google: config.isGoogleEnable,
     ldap: config.isLDAPEnable,
     ldapProviderName: config.ldap.providerName,
+    oauth2ProviderName: config.oauth2.providerName,
     saml: config.isSAMLEnable,
+    oauth2: config.isOAuth2Enable,
     email: config.isEmailEnable,
     allowEmailRegister: config.allowEmailRegister,
     allowPDFExport: config.allowPDFExport
diff --git a/lib/web/auth/index.js b/lib/web/auth/index.js
index eb42fb36..61e7c3f9 100644
--- a/lib/web/auth/index.js
+++ b/lib/web/auth/index.js
@@ -43,6 +43,7 @@ if (config.isDropboxEnable) authRouter.use(require('./dropbox'))
 if (config.isGoogleEnable) authRouter.use(require('./google'))
 if (config.isLDAPEnable) authRouter.use(require('./ldap'))
 if (config.isSAMLEnable) authRouter.use(require('./saml'))
+if (config.isOAuth2Enable) authRouter.use(require('./oauth2'))
 if (config.isEmailEnable) authRouter.use(require('./email'))
 
 // logout
diff --git a/lib/web/auth/oauth2/index.js b/lib/web/auth/oauth2/index.js
new file mode 100644
index 00000000..f2a3132d
--- /dev/null
+++ b/lib/web/auth/oauth2/index.js
@@ -0,0 +1,106 @@
+'use strict'
+
+const Router = require('express').Router
+const passport = require('passport')
+const OAuth2Strategy = require('passport-oauth2').Strategy
+const config = require('../../../config')
+const {setReturnToFromReferer, passportGeneralCallback} = require('../utils')
+
+let oauth2Auth = module.exports = Router()
+
+class OAuth2CustomStrategy extends OAuth2Strategy {
+  constructor (options, verify) {
+    options.customHeaders = options.customHeaders || {}
+    super(options, verify)
+    this.name = 'oauth2'
+    this._userProfileURL = options.userProfileURL
+    this._oauth2.useAuthorizationHeaderforGET(true)
+  }
+
+  userProfile (accessToken, done) {
+    this._oauth2.get(this._userProfileURL, accessToken, function (err, body, res) {
+      var json
+
+      if (err) {
+        return done(new passport.InternalOAuthError('Failed to fetch user profile', err))
+      }
+
+      try {
+        json = JSON.parse(body)
+      } catch (ex) {
+        return done(new Error('Failed to parse user profile'))
+      }
+
+      let profile = parseProfile(json)
+      profile.provider = 'oauth2'
+
+      done(null, profile)
+    })
+  }
+}
+
+function extractProfileAttribute (data, path) {
+  // can handle stuff like `attrs[0].name`
+  path = path.split('.')
+  for (const segment of path) {
+    const m = segment.match(/([\d\w]+)\[(.*)\]/)
+    data = m ? data[m[1]][m[2]] : data[segment]
+  }
+  return data
+}
+
+function parseProfile (data) {
+  const username = extractProfileAttribute(data, config.oauth2.userProfileUsernameAttr)
+  const displayName = extractProfileAttribute(data, config.oauth2.userProfileDisplayNameAttr)
+  const email = extractProfileAttribute(data, config.oauth2.userProfileEmailAttr)
+
+  return {
+    id: username,
+    username: username,
+    displayName: displayName,
+    email: email
+  }
+}
+
+OAuth2CustomStrategy.prototype.userProfile = function (accessToken, done) {
+  this._oauth2.get(this._userProfileURL, accessToken, function (err, body, res) {
+    var json
+
+    if (err) {
+      return done(new passport.InternalOAuthError('Failed to fetch user profile', err))
+    }
+
+    try {
+      json = JSON.parse(body)
+    } catch (ex) {
+      return done(new Error('Failed to parse user profile'))
+    }
+
+    let profile = parseProfile(json)
+    profile.provider = 'oauth2'
+
+    done(null, profile)
+  })
+}
+
+passport.use(new OAuth2CustomStrategy({
+  authorizationURL: config.oauth2.authorizationURL,
+  tokenURL: config.oauth2.tokenURL,
+  clientID: config.oauth2.clientID,
+  clientSecret: config.oauth2.clientSecret,
+  callbackURL: config.serverURL + '/auth/oauth2/callback',
+  userProfileURL: config.oauth2.userProfileURL
+}, passportGeneralCallback))
+
+oauth2Auth.get('/auth/oauth2', function (req, res, next) {
+  setReturnToFromReferer(req)
+  passport.authenticate('oauth2')(req, res, next)
+})
+
+// github auth callback
+oauth2Auth.get('/auth/oauth2/callback',
+  passport.authenticate('oauth2', {
+    successReturnToOrRedirect: config.serverurl + '/',
+    failureRedirect: config.serverurl + '/'
+  })
+)