My guess at this is that your client and server may not have a cipher suite in common. vCenter 5.5 is very old and most, if not all, of the cipher suites from that time have been deprecated.
You can test by running this command on both ends and looking for a common suite in both lists:
Original Message:
Sent: Apr 20, 2025 11:02 PM
From: Ben Tang
Subject: vcenter 5.5 ssl certificate expired
I check the cert rui.crt I generated and the native cert rui.crt.bak.
The rui.crt's issuer and subject are identical. But the rui.crt.bak's are not.
The rui.crt.bak's issuer is "C=US, ST=California, L=Palo Alto, O=VMware Inc., CN=FQDN CA beffae4f/emailAddress=ssl-certificates@vmware.com". And the subject is "C=US, ST=California, L=Palo Alto, O=VMware Inc., OU=VMware vCenter Server Certificate/emailAddress=ssl-certificates@vmware.com, CN=FQDN/unstructuredName=..."
And I try to use the sha256 and 2048 key bits arguments(Because the rui.crt.bak used these arguments) with your command to generate my cert. But it also doesn't work.
Original Message:
Sent: Apr 19, 2025 04:19 PM
From: Andrea Consalvi
Subject: vcenter 5.5 ssl certificate expired
Hi Ben,
I'm sorry to hear the issue is still persisting even after including the SANs.
At this point, the error "Server certificate chain not verified" and "SslHandshakeFailed" indicates that the problem is not with the SANs anymore, but with the trust chain of the certificate itself.
When using vCenter 5.5, the certificate must either:
- Be self-signed and correctly located in the vCenter paths,
OR - Be signed by a trusted Certificate Authority (CA) that is present in the Java truststore used by vCenter services.
Here's what you can do next to verify:
- Double-check that your certificate is self-signed using:
openssl x509 -in rui.crt -noout -issuer -subject
- If issuer and subject are identical, it's self-signed.
- If it's self-signed, make sure:
- It's 2048-bit RSA.
- It includes valid SANs (which you've already done).
- It's copied correctly to /etc/vmware-vpx/ssl/.
- If it's not self-signed, you must import the issuing CA into the Java truststore used by vCenter.
Unfortunately, in vCenter 5.5 this process was fragile and not always reliable sometimes a full reinstallation with new certs was the only way out.
Original Message:
Sent: Apr 17, 2025 12:36 AM
From: Ben Tang
Subject: vcenter 5.5 ssl certificate expired
I use your updated command, the result and the cert content about SANs are following. And the error still occurs. I think it's a big trouble. LOL!!!
Thanks again for your help!!!
Original Message:
Sent: Apr 16, 2025 07:53 AM
From: Andrea Consalvi
Subject: vcenter 5.5 ssl certificate expired
Hi Ben, I knew it was going to be tough with 5.5. The error you're getting (CertificateValidationException: Server certificate chain not verified
) suggests that the certificate was generated, but it's still missing one of the Subject Alternative Names (SANs) expected by vCenter Lookup Service.
Here are a few things to check that are essential:
The CN must exactly match the vCenter's FQDN
→ e.g. /CN=vcenter.lab.local
The SAN must include at least:
If you skip any of those, Lookup Service will fail.
Verify there are no hidden characters in the generated cert
Sometimes, copying commands from the browser can introduce invisible characters or wrong quotes (like smart quotes ""
instead of ""
). Use a raw text editor on Linux (like nano
or vi
).
Try this updated OpenSSL command (replace FQDN and IP accordingly):
Then copy the certs:
And restart the service:
Let me know how it goes if it still fails, we'll look at the SAN content in the certificate directly using:
This will confirm exactly what SANs were included.
Original Message:
Sent: Apr 15, 2025 10:57 PM
From: Ben Tang
Subject: vcenter 5.5 ssl certificate expired
Hi Andrea,
I use your command to get the rui.key and rui.crt, but it still doesn't work.

Original Message:
Sent: Apr 14, 2025 08:07 AM
From: Andrea Consalvi
Subject: vcenter 5.5 ssl certificate expired
Hi Ben,
in vCenter 5.5, even with a correctly generated certificate, components like SSO and LookupService often reject it if the SAN section is missing or incomplete. This is usually the cause behind the "certificate chain not verified" and "SSLHandshakeFailed" messages you're seeing.
Your current .cnf
includes the SAN, but depending on how it's parsed and passed by openssl
, some fields might be skipped or ignored. That's why I suggested injecting the SAN block dynamically via cat
and printf
, which helps force OpenSSL to merge it correctly during the request generation - especially in older vCenter setups.
If you're still seeing the error even with this config, I'd retry the certificate creation using the inline openssl
command I posted earlier, making sure the SAN includes:
The vCenter FQDN
The vCenter IP address
Optionally: localhost
Once regenerated, overwrite rui.crt
and rui.key
under /etc/vmware-vpx/ssl/
, then restart the service:
If after that you're still stuck at the handshake step, we can try reviewing the STS certificate and truststore chain next.
Original Message:
Sent: Apr 11, 2025 11:29 AM
From: Ben Tang
Subject: vcenter 5.5 ssl certificate expired
I made a config file for cert like the following before:
[ req ]
default_bits = 2048
default_keyfile = rui.key
distinguished_name = req_distinguished_name
encrypt_key = no
prompt = no
string_mask = nombstr
req_extensions = v3_req
input_password = testpassword
output_password = testpassword
[ v3_req ]
basicConstraints = CA:false
keyUsage = digitalSignature, keyEncipherment, dataEncipherment
extendedKeyUsage = serverAuth, clientAuth
subjectAltName = DNS:vcva55, IP: 10.0.0.10, IP:ServerIPv6Address, DNS: vcva55.vmware.com
[ req_distinguished_name ]
countryName = US
stateOrProvinceName = NY
localityName = New York
0.organizationName = VMware
organizationalUnitName = vCenterApplianceUniqueServer
commonName = vcva55.vmware.com
and the SANs information I got from the old rui.crt in the location "/etc/vmware-vpx/ssl/" with the openssl command. So far, I still use this template to generate the various certificates with the openssl command.
The procedures I follow are from the url "https://community.broadcom.com/vmware-cloud-foundation/discussion/vcenter-server-550-windows-server-certificate-expired". But it can also do nothing.
Original Message:
Sent: Apr 11, 2025 08:35 AM
From: Andrea Consalvi
Subject: vcenter 5.5 ssl certificate expired
Hi Ben,
The error you're seeing now about the certificate chain not being verified is expected when using a generic self-signed certificate that doesn't include all the required fields. In vCenter 5.5, internal components like LookupService or SSO require not only a valid certificate, but one that includes the correct Subject Alternative Names (SANs), otherwise the handshake fails.
I suggest regenerating the certificate using OpenSSL, but this time making sure to add the SAN extension with the FQDN, IP address, and optionally localhost. This has solved the same issue in other vSphere 5.5 environments where the vpxd service would start but LookupService would still reject the cert.
example:
Make sure to replace the FQDN and IP with your actual vCenter hostname and IP address. Once the files are generated, copy them back to /etc/vmware-vpx/ssl/
, then restart the vpxd service:
This usually allows internal services to trust the certificate again and resolve the handshake issue.
Original Message:
Sent: Apr 11, 2025 01:13 AM
From: Ben Tang
Subject: vcenter 5.5 ssl certificate expired
Hi Andrea,
Thanks for your help.
I try the method you provide. But unfortunately, it don't take effect. After I copy the rui.crt and rui.key, I try to restart the vmare-vpxd service, but I get the error "Getting SSL certificates for https://FQDN:7444/lookupservice/sdk com.vmware.vim.vmomi.core.exception.CertificateValidationException: Server certificate chain not verified Return code is: SslHandshakeFailed", and show "Waiting for vpxd to initialize: .failed". So when I try to login in to the web client, it shows the error "can not connect to the vCenter Single Sign-On Server https://FQDN:7444/sts/STSService/vsphere/local", the error I also got before.
What should I do next? I had also tried to modify the system datetime before, but it didn't take effect.
Original Message:
Sent: Apr 10, 2025 09:53 AM
From: Andrea Consalvi
Subject: vcenter 5.5 ssl certificate expired
Hi Ben,
vCenter 5.5 has been officially out of support since 2020, so it's expected that tools and documentation related to cert-manager and SSL certificates are no longer available through current Broadcom/VMware channels.
The errors you received:
"failed to connect to vmware lookup service" and
"sdk-ssl certificate verification failed"
are unfortunately a classic sign that the vCenter SSL certificates have expired.
The command vpxd_servicecfg certificate change
often no longer works once the certificates have already expired, and the error VC_CFG_RESULT=650
is just a generic confirmation that the procedure failed. If you want to attempt a recovery, here's a method (not guaranteed, but it has worked in some cases):
Rename the expired certificates:
Generate a new self-signed certificate:
You'll be asked for some parameters. Fill them out, making sure the CN matches the FQDN of the vCenter (e.g., vcenter.lab.local
).
Copy the new files to the vCenter SSL directory:
Restart the vCenter services:
After this attempt, try accessing the vSphere Web Client or connecting via browser again. If it works, you might get a warning about an untrusted certificate, but the service should be operational again.
Original Message:
Sent: Apr 09, 2025 01:20 AM
From: Ben Tang
Subject: vcenter 5.5 ssl certificate expired
Hello,everyone
My vsphere vcenter version is 5.5, I got an error "failed to connect to vmware lookup service https://xxxx:7444/lookupservice/sdk-ssl certificate verification failed" when I intended to log in to the vsphere web client and got an other error "wrong user or password" when logged in to the vsphere client. So then I searched the Internet, I found that those errors were caused by SSL certificate expired for vcenter. I verified this after I checked the relevant certificates in my vcenter for suse linux machine. I found the certificates were expired in Feb,2025. And then I got a tutorial about fixing this problem in the url "https://paulgrevink.wordpress.com/?s=Implementing+CA+signed+SSL+certificates+with+vSphere+5.x+". I followed it step by step. But when I proceeded to Part 3, I got "VC_CFG_RESULT=650" error(it must be code 0 if the command succeeded) when I used the "/usr/sbin/vpxd_servicecfg certificate change" command. I wanted to find out what this meant. But I got nothing when I searched the broadcom website. The website no longer provided any service for vcenter 5.5. And the KB article about 5.5 were not found in it.
I've been trying to search out how to solve this, but still haven't. So anyone can help??