Title: Cannot complete login process
Last modified: June 2, 2020

---

# Cannot complete login process

 *  Resolved [webgroupf](https://wordpress.org/support/users/webgroupf/)
 * (@webgroupf)
 * [6 years ago](https://wordpress.org/support/topic/cannot-complete-login-process/)
 * After entering user name and password into CAS login form, CAS redirect me to
   my site with the following error, and I cannot complete login:
 * Warning: Cannot modify header information – headers already sent by (output started
   at /home/domain/wp-content/plugins/authorizer/vendor/phpCAS-1.3.6/source/CAS/
   Client.php:80) in /home/domain/wp-content/plugins/authorizer/vendor/phpCAS-1.3.6/
   source/CAS/Client.php on line 1695
 * The page I need help with: _[[log in](https://login.wordpress.org/?redirect_to=https%3A%2F%2Fwordpress.org%2Fsupport%2Ftopic%2Fcannot-complete-login-process%2F%3Foutput_format%3Dmd&locale=en_US)
   to see the link]_

Viewing 9 replies - 1 through 9 (of 9 total)

 *  Plugin Author [Paul Ryan](https://wordpress.org/support/users/figureone/)
 * (@figureone)
 * [6 years ago](https://wordpress.org/support/topic/cannot-complete-login-process/#post-12928618)
 * Sounds like you either have `WP_DEBUG_DISPLAY` turned on, and it’s echoing something
   to the client before the CAS response has completed. Or you have theme or plugin
   code that unintentionally echos whitespace. See this for details:
    [https://premium.wpmudev.org/blog/fixing-cannot-modify-header-error/](https://premium.wpmudev.org/blog/fixing-cannot-modify-header-error/)
 *  Thread Starter [webgroupf](https://wordpress.org/support/users/webgroupf/)
 * (@webgroupf)
 * [6 years ago](https://wordpress.org/support/topic/cannot-complete-login-process/#post-12928957)
 * Yes, I turned on WP_DEBUG_DISLAY so that I could see any errors. I have about
   ten different sites that are using Authorizer, and as of this morning, I cannot
   log into any of those sites with Authorizer. They all use different themes and
   have a mix of plugins and they all return the same error (in the text below [
   domain] replaces name of actual folder):
 * ———–START————–
    CAS Authentication failed!
 * You were not authenticated.
 * You may submit your request again by clicking here.
 * If the problem persists, you may contact the administrator of this site.
 * Warning: Cannot modify header information – headers already sent by (output started
   at /home/[domain]/references/wp-content/plugins/authorizer/vendor/phpCAS-1.3.6/
   source/CAS/Client.php:80) in /home/[domain]/references/wp-content/plugins/authorizer/
   vendor/phpCAS-1.3.6/source/CAS/Client.php on line 1695
 * CAS logout wanted!
 * You should already have been redirected to the CAS server. Click here to continue.
 * ———-END—————–
 * The site I am using to test and find a fix is [https://testsite.ufordh.am/references](https://testsite.ufordh.am/references).
   It has only one plugin (Authorizer) and uses a default WordPress theme (twenty-
   twenty), php 7.3, Apache 2.2.
 * I can successfully authenticate and log into my non-Wordpress apps using PHPCAS,
   which are on the same server as my WordPress apps where I am using Authorizer.
 *  Plugin Author [Paul Ryan](https://wordpress.org/support/users/figureone/)
 * (@figureone)
 * [6 years ago](https://wordpress.org/support/topic/cannot-complete-login-process/#post-12929330)
 * Don’t use `WP_DEBUG_DISPLAY`, look at the server logs instead. Echoing the errors
   to the client causes the problem you are seeing. If anything has been echoed 
   before PHP writes HTTP headers with `header()`, then you see that message.
    [https://www.php.net/manual/en/function.header.php](https://www.php.net/manual/en/function.header.php)
 *  Thread Starter [webgroupf](https://wordpress.org/support/users/webgroupf/)
 * (@webgroupf)
 * [6 years ago](https://wordpress.org/support/topic/cannot-complete-login-process/#post-12932232)
 * Paul,
 * WP_DEBUG_DISPLAY is set to false
 * The WordPress Dashboard for Authorizer shows:
 * Authorizer Settings
    Can’t reach CAS server. Please provide accurate CAS settings
   if you intend to use it.
 * None of the CAS settings for any of my WordPress sites have changed in the last
   few years, and I can successfully authenticate and login with the same settings
   with my non-Wordpress sites on the same server.
 * The error log shows:
 * [Wed Jun 03 00:05:51 2020] [warn] RSA server certificate is a CA certificate (
   BasicConstraints: CA == TRUE !?)
    [Wed Jun 03 00:07:07 2020] [warn] RSA server
   certificate is a CA certificate (BasicConstraints: CA == TRUE !?)
 *  Thread Starter [webgroupf](https://wordpress.org/support/users/webgroupf/)
 * (@webgroupf)
 * [6 years ago](https://wordpress.org/support/topic/cannot-complete-login-process/#post-12932605)
 * Additional error info:
 * [Wed Jun 03 06:55:32 2020] [warn] [client 173.56.121.24] mod_fcgid: stderr: CAS
   server returned an Authentication Exception. Details:, referer: [https://loginp.fordham.edu/cas/login?service=https%3A%2F%2Ftestsite.ufordh.am%2Freferences%2Fwp-login.php%3Fexternal%3Dcas%26redirect_to%3Dhttps%253A%252F%252Ftestsite.ufordh.am%252Freferences%252Fwp-admin%252F](https://loginp.fordham.edu/cas/login?service=https%3A%2F%2Ftestsite.ufordh.am%2Freferences%2Fwp-login.php%3Fexternal%3Dcas%26redirect_to%3Dhttps%253A%252F%252Ftestsite.ufordh.am%252Freferences%252Fwp-admin%252F)
   [
   Wed Jun 03 06:55:32 2020] [warn] [client 173.56.121.24] mod_fcgid: stderr: CAS
   URL: [https://loginp.fordham.edu/cas/samlValidate?TARGET=https%3A%2F%2Ftestsite.ufordh.am%2Freferences%2Fwp-login.php%3Fexternal%3Dcas%26redirect_to%3Dhttps%253A%252F%252Ftestsite.ufordh.am%252Freferences%252Fwp-admin%252F](https://loginp.fordham.edu/cas/samlValidate?TARGET=https%3A%2F%2Ftestsite.ufordh.am%2Freferences%2Fwp-login.php%3Fexternal%3Dcas%26redirect_to%3Dhttps%253A%252F%252Ftestsite.ufordh.am%252Freferences%252Fwp-admin%252F),
   referer: [https://loginp.fordham.edu/cas/login?service=https%3A%2F%2Ftestsite.ufordh.am%2Freferences%2Fwp-login.php%3Fexternal%3Dcas%26redirect_to%3Dhttps%253A%252F%252Ftestsite.ufordh.am%252Freferences%252Fwp-admin%252F](https://loginp.fordham.edu/cas/login?service=https%3A%2F%2Ftestsite.ufordh.am%2Freferences%2Fwp-login.php%3Fexternal%3Dcas%26redirect_to%3Dhttps%253A%252F%252Ftestsite.ufordh.am%252Freferences%252Fwp-admin%252F)[
   Wed Jun 03 06:55:32 2020] [warn] [client 173.56.121.24] mod_fcgid: stderr: Authentication
   failure: SA not validated, referer: [https://loginp.fordham.edu/cas/login?service=https%3A%2F%2Ftestsite.ufordh.am%2Freferences%2Fwp-login.php%3Fexternal%3Dcas%26redirect_to%3Dhttps%253A%252F%252Ftestsite.ufordh.am%252Freferences%252Fwp-admin%252F](https://loginp.fordham.edu/cas/login?service=https%3A%2F%2Ftestsite.ufordh.am%2Freferences%2Fwp-login.php%3Fexternal%3Dcas%26redirect_to%3Dhttps%253A%252F%252Ftestsite.ufordh.am%252Freferences%252Fwp-admin%252F)[
   Wed Jun 03 06:55:32 2020] [warn] [client 173.56.121.24] mod_fcgid: stderr: Reason:
   no response from the CAS server, referer: [https://loginp.fordham.edu/cas/login?service=https%3A%2F%2Ftestsite.ufordh.am%2Freferences%2Fwp-login.php%3Fexternal%3Dcas%26redirect_to%3Dhttps%253A%252F%252Ftestsite.ufordh.am%252Freferences%252Fwp-admin%252F](https://loginp.fordham.edu/cas/login?service=https%3A%2F%2Ftestsite.ufordh.am%2Freferences%2Fwp-login.php%3Fexternal%3Dcas%26redirect_to%3Dhttps%253A%252F%252Ftestsite.ufordh.am%252Freferences%252Fwp-admin%252F)[
   Wed Jun 03 06:55:32 2020] [warn] [client 173.56.121.24] mod_fcgid: stderr: PHP
   Warning: Cannot modify header information – headers already sent by (output started
   at ../wp-content/plugins/authorizer/vendor/phpCAS-1.3.6/source/CAS/Client.php:
   80) in ../wp-content/plugins/authorizer/vendor/phpCAS-1.3.6/source/CAS/Client.
   php on line 1695, referer: [https://loginp.fordham.edu/cas/login?service=https%3A%2F%2Ftestsite.ufordh.am%2Freferences%2Fwp-login.php%3Fexternal%3Dcas%26redirect_to%3Dhttps%253A%252F%252Ftestsite.ufordh.am%252Freferences%252Fwp-admin%252F](https://loginp.fordham.edu/cas/login?service=https%3A%2F%2Ftestsite.ufordh.am%2Freferences%2Fwp-login.php%3Fexternal%3Dcas%26redirect_to%3Dhttps%253A%252F%252Ftestsite.ufordh.am%252Freferences%252Fwp-admin%252F)
 *  Plugin Author [Paul Ryan](https://wordpress.org/support/users/figureone/)
 * (@figureone)
 * [6 years ago](https://wordpress.org/support/topic/cannot-complete-login-process/#post-12934033)
 * Might be possible that openssl on one of your servers is outdated, and falling
   victim to this:
    [https://www.cmu.edu/iso/service/cert-auth/addtrust.html](https://www.cmu.edu/iso/service/cert-auth/addtrust.html)
 * I know our university replaced SSL certs on our CAS server to remove the AddTrust
   root CA from the chain.
 *  Thread Starter [webgroupf](https://wordpress.org/support/users/webgroupf/)
 * (@webgroupf)
 * [6 years ago](https://wordpress.org/support/topic/cannot-complete-login-process/#post-12939352)
 * Paul,
 * With your help we were able to see what it is that is likely causing the problem,
   which is our OpenSSL version 1.0.1
 * Our hosting provider suggests an OS upgrade (Ubuntu v14 to v18), but in the meantime,
   I removed the AddTrust cert from the ca-bundle.crt in “/wp-includes/certificates/
   ca-bundle.crt”. This revision lets Authorizer connect to the CAS server and successfully
   authenticate.
 * We know this will get overwritten by future WP upgrades, but we needed a solution
   immediately until our ISP can permanently resolve.
 * Thank you so much.
 *  Thread Starter [webgroupf](https://wordpress.org/support/users/webgroupf/)
 * (@webgroupf)
 * [6 years ago](https://wordpress.org/support/topic/cannot-complete-login-process/#post-12939413)
 * Follow up question:
 * Please forgive my ignorance, but when you stated that your “university replaced
   SSL certs on our CAS server to remove the AddTrust root CA from the chain”, were
   you implying that if our CAS server has an AddTrust root CA in its cert chain
   and we remove it, then OpenSSL versions which are failing because of the expired
   root CA will succeed? Or is it more complicated that this?
 *  Plugin Author [Paul Ryan](https://wordpress.org/support/users/figureone/)
 * (@figureone)
 * [6 years ago](https://wordpress.org/support/topic/cannot-complete-login-process/#post-12939913)
 * Glad you isolated the problem! Updating the OS is probably the best long term
   strategy; Ubuntu 14.04 LTS is no longer supported so there are other security
   risks there too. Ubuntu 20.04 LTS is out now too, so that or 18.04 are both in
   active support.
 * Here’s our university’s language on their actions:
    [https://www.hawaii.edu/bwiki/pages/viewpage.action?pageId=721619543](https://www.hawaii.edu/bwiki/pages/viewpage.action?pageId=721619543)
   Specifically:
 * > ITS will be updating the intermediate InCommon certificates bundle
 * I don’t think they replaced the SSL certs themselves, only the intermediates.
   In apache, this is usually specified in `SSLCertificateChainFile`:
    [https://httpd.apache.org/docs/current/mod/mod_ssl.html#sslcertificatechainfile](https://httpd.apache.org/docs/current/mod/mod_ssl.html#sslcertificatechainfile)
 * That said, I think your short term fix (modifying WordPress’s ca-bundle.crt) 
   should be fine. Historically, WordPress has only updated the bundle infrequently
   so it’s unlikely to get overwritten in the near future.
    [https://github.com/WordPress/WordPress/commits/master/wp-includes/certificates/ca-bundle.crt](https://github.com/WordPress/WordPress/commits/master/wp-includes/certificates/ca-bundle.crt)

Viewing 9 replies - 1 through 9 (of 9 total)

The topic ‘Cannot complete login process’ is closed to new replies.

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## Tags

 * [login](https://wordpress.org/support/topic-tag/login/)

 * 9 replies
 * 2 participants
 * Last reply from: [Paul Ryan](https://wordpress.org/support/users/figureone/)
 * Last activity: [6 years ago](https://wordpress.org/support/topic/cannot-complete-login-process/#post-12939913)
 * Status: resolved