Bug Reference

CLOUDSTACK-4821

Introduction

SSL Offloading feature allows loadbalancers to handle encryption/decryption of HTTP(s) traffic giving plaintext HTTP to the backend servers freeing them from the resource intensive task of handling encryption/decryption. Major loadblancers like the Netscaler and F5 have this functionality. This document is a functional sepc for adding certificate mangaement on cloudstack and implement implementing SSL offload capability for cloudstack provisioned loadbalancers.

Goals

1. A user should be able to create/update/delete SSL certs for his account.
2. Certificates can be searched by using either the certificate ID or the account ID.
3. Attach/Remove a certificate from a loadbalancers which support SSL offload feature.
4. Add support for Netscaler to use this feature.

References

• http://support.citrix.com/proddocs/topic/netscaler/ns-ssl-wrapper-con-92.html^{Image Removed}
• AWS API for Upload, Delete, List, Update SSL Certificates.
• AWS API for assigning certificate to LB , Updating certificate for a LB and Unset certificate from LB, but does not work
• StackOverflow thread for the unset SSL certificate issue in AWS.

Document History

Functional requirements & non-requirements

1. Introduce a new entity SSLCerts linked to a user account
2. Users should be able to Add/Delete/List certificates linked to their account
3. Admin should be able to list all the certificates for all accounts
4. When creating a loadbalancer if the public port is 443 and the private port is 80, then
   • If the loadbalancer device supports SSL offloading,
     • The loadbalncer created should be of type SSL.
     • Should allow attach/remove of a SSL certificate to it.
   • If the loadblancner loadbalancer device does not support ssl offload,
     • The loadbalncer loadbalancer type will be TCP.
     • Trying to attach a certificate to it should generate an error
5. Users should be able to attach/remove their certificates to their loadbalancers.
6. Deleting a SSL certificate should also remove it from all the loadbalancers it is attached to. throw an error stating that it is already in use
7. If a user account gets deleted, the associated Certificates should also be deleted.
8. If a loadbalancer gets deleted, the associated binding should also be deleted.
9. The private key and password for the key should be stored encrypted

Architecture and Design description

...

TODO Document Design

Assumptions

• The SSL certificates should include the chain trust with them. They are added to the device as-is. ( Cert chain will be passed as an optional argument )
• For the netscaler loadbalancer, we assume that the port 22 is open and there is space in /nsconfig as we scp the certificate to the device.
• A loadbalancer rule can have only one certificate attached to it. A certificate however can be attached to multiple loadbalancers ( As long they are SSL type ). Support for multiple certificates for a single loadbalancer is not scoped.
• The certificate is not checked for validity at cloudstack level. The device errors if the certificate is invalid ( Certificate validation happens at cloudstack )

Design

General Flow for assign/remove SSL certificate to a load balancer

• when calling AssignToLoadBalancerRule if there is a certificate id in the request execute() method of the command calls
  assignSslCertToLoadBalancer(lb_id, certId) in LoadBalancingRulesManagerImpl
• assignSslCertToLoadBalancer checks if the loadbalancer is capable of SSL. If not error is returned.
• verify if other certificate is bound to the loadbalancer and if it is, return error
• It then verifies if the certificate is valid ( not revoked ) and creates an entry in the load_balancer_cert_map table
• the loadbalancer state is set to Add
• call the applyLoadBalancerConfig which calls applyLoadBalancerRules with the lbId
• getLoadBalancerRuleToApply function should also add getSslCertificates(lbId) which gets called from applyLoadBalancerConfig
• Now the rule has SSL certificate info as well.
• When the rules get applied by calling applyLBRules of the NetscalerElement, the SSL info is passed inside the rule.
• Netscaler should check for SslOffload Capability if the rule has certificate info.
• NetscalerElement creates a LoadBalancerTO which transfers the params to the resource layer.
• The LoadBalancerTO should contain SslCertTO for holding certificate information.

New classes and fields

• The SSL offload will be defined as a new Capability as SslOffload in Network.java static class Capability
• NetscalerElement when checking for canHandleLbRules will check for SSL rule and respond accordingly
• LoadBalancingRule will have a new static class LbSslCert and will have a list List<LbSslCert> for holding the certificate(s)
• LoadBalancerTO will have a new parameter for passing certificate information and an array SslCertsTO[] for holding the certificates.

The loadbalancign rule will have a new subclass for SSL certs

// rule for SSL certificates
public class LoadBalancingRule {
 ....

  public static class LbSslCert()
  {
    String cert;
    String key;
    String password;
    boolean _revoke;

    public LbSslCert(cert,key,password) {}

  }

  public void setSslCerts(List<SslCert> certs){}
  public void getSslCerts(List<SslCert> certs){}
...
}

The transfer object should also be able to pass SSL certs

// TO for SSL certificates
public class LoadBalancerTO {
 ....
  public SslCertsTO[] sslCerts;

  public static class SslCertTO()
  {
    String cert;
    String key;
    String password;
    boolean _revoke;

    public LbSslCert(cert,key,password) {}

  }

...
}

New tables

ssl_certs(id, uuid, account_id, cert, key, password)

load_balancer_cert_map(id, load_balancer_id, certitficate_id, revoke, state)

New

...

Webservice APIs for Certificate Management

This section lists the new webservice APIs for Certificate management. They are derived from their AWS Equivalant ( UploadServerCertificate, ListServerCertificates, GetServerCertificate, DeleteServerCertificate )

uploadSSLCert

Uploads a new SSL certificate-key pair

Request parameters:

• cert certificate : Required : The public certificate, should also include the trust chain if required
• key privatekey : Required : The private key for the certificate, if the key is encrypted, password should be provided
• chain: Optional : The certificate chain
• password: Optional : The password for the private key
• account: Optional : The account to associate with the cert
• domainid: Optional : The domain to associate with the cert
• projectid: Optional : The project to associate with the cert

Response parameters:

• id : The ID of the certificate
• account : The account of the SSL certificate
• cert : public certificate
• key : private key

...

• chain : The certificate chain
• domainid : The domain id associated with the cert
• domain : The domain name associated with the cert
  -- either --
• account : The account associated with the cert
  -- or --
• projectid : The project id associated with the cert
• project : The project name associated with the cert

http://10.x.x.x:8080/client/api?command=uploadSslCert&certificate=-----BEGIN+CERTIFICATE-----<certificate>-----END+CERTIFICATE-----&privatekey=-----BEGIN+RSA+PRIVATE+KEY----<privatekey>-----END+RSA+PRIVATE+KEY-----

Note : The certificate,key and chain should be UTF-encoded in the URL. ssl_certs(id, uuid, account_id, cert, key, password)

deleteSSLCert

Deletes an existing SSL cert from cloudstack.

...

• id : Required : The id of the certificate

updateSSLCert

updates an existing certificate-key pair

Request parameters:

Response parameters:

• displaytext : any text associated with the success or failure
• success : true if operation is executed successfully

http://10.x.x.x:8080/client/api?command=deleteSslCert&id=7

listSSLCerts

The response is a list of following

• id id : Required : The id of the certificate
• cert : Optional : The public certificate, should also include the trust chain if required
• key : Optional : The private key for the certificate, if the key is encrypted, password should be provided
• password: Optional : The password for the private key

listSSLCerts

lists the certificates for an Id or an account

Request parameters:

• id : Optional : The id of the certificate
• accountid : Optional : The account id for which the certs are to be listed

• chain : The certificate chain
• account : The account associated with the certificate
• lbruleid : The lb rule associated with the certificate
• projectid : The project associated with the certificate

http://10.x.x.x:8080/client/api?command=listSslCerts&accountid=2

New Apis  to add SSL cets to LBs

...

For associating the certificates to loadbalancing rules, we need to add have the certificate id parameter to following loadbalancer apis.

assignToLoadBalancerRule

Request parameter to be added:

following APIs

assignCertToLoadBalancer

Request parametes:

• certid: Required certificateid: Optional : The id of the certificate to assign to this rule.

New tables:

load_balancer_cert_map(id, load_balancer_id, cert_id, revoke, state)

• lb_id:Required : The lb rule to assign the cert to

http://10.x.x.x:8080/client/api?command=assignCertToLoadBalancer&certid=138ad12e-a486-44e3-bb02-7a55d0813174&lbruleid=47

removeCertFromLoadBalancer

...

Request parameter to be added:

• certificateidlbruleid: Optional : The id of the certificate to remove from this rule.

http://10.x.x.x:8080/client/api?command=removeCertFromLoadBalancer&lbruleid=47

UI flow

The certificates can be accessed as a tab on the Accounts page.

Add Certificate

Image Added

List Certificates

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Certificate details

Note: I cannot get the certificate to display as a block.

The actual certificate looks like this

-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Image Added

Assign Certificate to Rule

Image Added

Assigned View

Image AddedRight now, this feature will only be available via the API. UI support is not yet scoped.

IP Clearance

No external dependecies are being added for this feature. All code will be developed within Cloudstack’s scope.