OAM - Deny if not protected Flag impact on webgate 10g and 11g

Ever wondered what does 'Deny if not protected 'flag signifies?

This flag is present in webgate profile, by default when you create a profile 10g or 11g, it is 'ON' or 'Checked'.

To whom does it impact?

Basically the significance of this flag is only for 10g webgate profiles. It has no impact on 11g webgates.

What impact does this flag has?

If this flag is set 'ON', than any resource which you are accessing & has no policy defined in OAM, than you will get 404 error. And the reason for this is 'Resource Access Denied'.

As in case of 10g you will face this problem, if this flag is set 'ON'.

Why this flag has no impact on 11g webgate?

The reason for this is: In case of 11g webgate by default access is denied for any resource whose policy is not defined in OAM.

If you want access for such resources than you have an option to make an unprotected/excluded resource type.

Enjoy :-)

OAM Webgate - Unable to get https redirect back to load balancer

Problem Description:

Load Balancer running on 'https' i.e. SSL enabled and behind it their is a web server (OTD/OHS/APACHE...any) on which webgate is integrated. 

The web server may be SSL enabled or may be not. But this webserver expects that the load balancer will tell about its SSL  state i.e. http or https. And this info actually not provided

Lets Understand the Use Case:

Say Load Balancer listening on - https://abc.com, the web server behind it is listening on http://xyz.abc.com:7777.

Now when the request lands on the load balancer it gives this request to the proxied web server where webgate redirects this to OAM Server by making a http://<host:port>/obrareq.cgi?<querystring> request.
OAM Server authenticates/authorizes the user's request & thus makes a redirect back to the server by making a http://<host:port>/obrar.cgi?<quesrystring> request. 

Thus here lies the issue, this obrar.cgi redirect should be on https:// rather it is on http://

Ever wondered why so; the reason is that the load balancer has not sent any info about its SSL state, that whether it is running in http or https mode.
That's why webgate has not given this same info to OAM Server, thus OAM server makes the obrar.cgi redirect on http instead of https.
 

Solution:

IS_SSL header is the solution; this header need to be set in the load balancer config file;
Now if load balancer is;

• Apache/OHS than one need to set this header in the virtual host config
• RequestHeader set IS_SSL ssl

• OTD; one need to set this in the server obj conf file;
• AuthTrans fn="set-variable" set-headers="is_ssl=ssl"     ;

After this restart the load balancer  ; test the use case & the issue is resolved;

Read More:
http://fusionsecurity.blogspot.in/2011/04/ssl-offloading-and-weblogic-server.html


Enjoy :-)

OAM R2PS3 - why there is need for 2 cwallet.sso files in webgate profile

Did you ever wondered that why there are 2 cwallet.sso files generated for your webgate profile in OAM R2PS3?

Let's take a look of the directory structure of the webgate profile when you create it;

• Here you see a cwallet.sso file & a wallet folder. This wallet folder was never there in previous releases, but from R2PS3 onwards you will see this folder as well..

Let' see what this folder contains;

• On expanding this wallet folder you see one more cwallet.sso file present int it.

bash-3.2$ ls -ltr
total 12
drwxr----- 2 ckukreja dba 4096 Oct 20 10:42 wallet
-rw-r----- 1 ckukreja dba 2796 Oct 20 10:42 ObAccessClient.xml
-rw-rw-rw- 1 ckukreja dba    0 Oct 20 10:42 cwallet.sso.lck
-rw------- 1 ckukreja dba  433 Oct 20 10:42 cwallet.sso   ----> this R2PS2 compatible wallet
bash-3.2$ cd wallet/
bash-3.2$ ls -ltr
total 4
-rw-rw-rw- 1 ckukreja dba   0 Oct 20 10:42 cwallet.sso.lck
-rw------- 1 ckukreja dba 401 Oct 20 10:42 cwallet.sso  -------> this R2PS3 compatible wallet

So the answer for these 2 cwallet.sso files is as follows:

• The cwallet.sso file present in wallet folder is R2PS3 compatible wallet, which means if you try to use this cwallet.sso file with R2PS2 webgate, it won't work. You will get FATAL error that "unable to read agent key". And thus webgate is not initialized successfully. 
• This cwallet.sso is used by R2PS3 webgate, but there is a catch here. Consider you don't copy the wallet folder to webgate instance directory in that case R2PS3 webgate is intelligent enough to understand the R2PS2 cwallet.sso.
• So this means that R2PS3 webgate can work with R2PS2 cwallet.sso as well as R2PS3 cwallet.sso.
• While the other cwallet.sso present outside is R2PS2 compatible wallet file i.e. when you try to use R2PS3 OAM Server with R2PS2 WebServer having R2PS2 Webgate. This cwallet.sso will be used by the webgate to read the agent key.
• This means that if this cwallet.sso is not present in that case R2PS2 webgate will be unable to initialize as it won't be able to read the agent key i.e. is present in cwallet.sso.
• Hence to make R2PS2 webgate work with R2PS3 OAM server it is mandatory to use the cwallet.sso file presnet outside the wallet folder.

  

There is one more change done in the cwallet.sso files for R2PS2 & R2PS3 created by R2PS3 OAM Server i.e.

• If you open the cwallet.sso of R2PS2 or R2PS3 it only contains shared secret key, there are no default certs present.

  

      Remember: to set the JAVA_HOME before you use the orapki command.

• While the cwallet.sso created by R2PS2 OAM Server used to contain default certs and the shared key.

Note: 

• To open R2PS3 cwallet.sso present in wallet folder you need the latest orapki executable which comes with R2PS3 OAM server, this same orapki can open the R2PS2 cwallet.sso as well. 
• But the orapki that comes with R2PS2 OAM Server will be unable to open R2PS3 wallet & will ask for login password in-spite of the fact that the cwallet.sso is auto login wallet.

Enjoy :-)

OAM - Webgate NAP Tunneling in OTD (R2PS2, R2PS3 & 12C)

As of now we all are aware how to tunnel a request to OAM through webgate, also we have covered this in Webgate NAP Tunneling.

But there is a catch or you can say you need to do one more step to enable NAP Tunneling when using OTD (Oracle Traffic Director) Server.

I am assuming you have followed all the steps that are mentioned in Webgate NAP Tunneling post. At the very last you need to perform one more step i.e. only for OTD;

1. To enable NAP Tunneling in OTD, one needs to uncomment a line mentioned in
   <instance_name>-obj.conf file which is as follows;
   
   #Uncomment the below line  and  configure "from" paramater for enable
   tunneling.  The value of from parameter would be the tunneled URLS
   #NameTrans fn="pfx2dir" from="/oam" dir="/webgate/otd/lib"
   name="webgate_response"
   
   Above line need to be uncommented, to make nap tunneling enable.
   After doing above change one needs to restart the OTD instance.
   
   Note: 
1. This configuration change, to enable NAP Tunneling, is their since
   R2PS2(with a BP Patch),R2PS3 which is the same carried forward to latest release i.e. 12c as well..
2. In the change suggested above you will find the tunneled urls, that you need to provide here by default it is /oam. But it might be possible you want to tunnel /oamfed as well.. or any other. So all the tunneled urls are to be provided here as well.

Enjoy :-)

User Defined Parameters in OAM 11G

The complete list of user defined parameters is described in the following oracle doc:

R2PS2:

http://docs.oracle.com/cd/E40329_01/admin.1112/e27239/register.htm#AIAAG5856

R2PS1:

http://docs.oracle.com/cd/E28271_01/doc.1111/e15478/shared.htm

OAM R2PS3 - no need to add cacert.pem or aaa_chain.pem in cwallet.sso anymore

With the recent release of Webgate R2PS3, now a new feature is added which saves manual intervention of adding cert in cwallet.sso for SIMPLE & CERT Mode.

Previously for SIMPLE/CERT Mode one needs to add the cacert.pem or aaa_chain.pem cert in the wallet. If not than handshake between webgate & oam is not done successfully.

But now webgate itself picks the cert from the desired location like;

• for simple mode -> cacert.pem is added in wallet which is placed at <webgate_install_dir>/tools/openssl/simpleCA directory location.
• for CERT Mode -> aaa_chain.pem needs to be added in wallet which is to be placed in webgate instance directory location.

So now when we start the webserver in which webgate is integrated, during SSL Handshake first time no cert is found in cwallet.sso hence "TLS Handshake failure" message is gets logged. After detecting this error webgate itself adds the cert in cwallet.sso & retry the handshake once again.

Hence this time all goes good & NAP Channel is initialized in secure mode.


Enjoy :-)

Understanding SSL Handshake Mechanism Between Webgate & OAM Server

Currently Webgate supports 3 modes of communication with OAM Server:

1. Open
2. Simple
3. Cert

With the SIMPLE & CERT Mode SSL comes in picture, but why at all we require it;

• The answer lies in the question it self i.e. security. OAM combined with Webgate is a security product that provides SSO & other features thus itself requires to be secure in talking terms.

From webgate-oam perspective we will be talking about NAP over SSL.

With SSL we ensure that the data transamitted b/w 2 parties is safe & sound as;

• Both the parties knows one another, but how because they do handshake before they start communication.
•  Once they start communicating, the packets or the data been transferred b/w them is secure as it is encrypted.

The 2 SSL modes of communication described above performs handshake process before they are sending data to each other; The handshake mechanism involves following steps;

Remember: In webgate & oam conversation, it is always the webgate who sends the request & server responds to it. So the request-response model is not vice-versa in OAM/Webgate case.   

1. In SSL Handshake first it is require for both client & server to ensure that they are talking to right or intended party only. So how webgate & oam do this;

1. It is the first INITIALIZE NAP message that is sent between both the parties;
2. This init_nap msg comprises of set of messages that they both exchange. And all this is done to ensure that the listener & receiver are not evil.
3. During this exchange webgate ask the server for the communication mode, if it is not open mode than webgate starts the SSL Handshake process. Describe in step 2.

2. At this step it is required to establish a secure connection between the webgate & oam. For this webgate prepare a CLIENT HELLO Message, which contains the following;

• Supported set of Cipher-suite like
  SSL_RSA_WITH_AES_256_CBC_SHA , SSL_RSA_WITH_3DES_EDE_CBC_SHA
• Which TLS Version to be supported; TLSv1.0, TLSv1.1, TLSv1.2; 
• Now webgate with r2ps3 also supports TLSv1.2 as well.

• Random Number - this number is of 32 bytes out of which 4 bytes contains date & time and rest are randomly generated. This random number will be used to prepare the master key (which is combination of client generated random number & server generated random number). This master key will be used for encrypting the data transferred b/w client & server once handshake is done.
• Session ID: a null session id is sent. If this is not the first time, than a valid value is been sent here as a session already exist b/w them.

 Cipher-suite: it is the algo that need to be used for encrypting the data.
 TLS version - it is the SSL supported version, latest one is TLSv1.2

3. Based on the Client Hello, server responds with SERVER HELLO, & in this server responds with;

• Supported cipher suite, that will be used in b/w webgate & oam for data encryption;
• Supported TLS version;
• And server sends its own certificate to webgate; And this is required to authenticate the server. Webgate does so by checking the cert in webgate truststore i.e. cwallet.sso. If webgate is able to verify the process is proceeded to next step, else it "TLS HANDSHAKE ERROR" is thrown.
• Possible reason for this:
• There is no trusted cert loaded in cwallet.sso, so webgate is unable to verify the server cert.
• Else the server provided cert is not a valid cert, hence server need to provide a valid cert.

• Random Number: server generated number same as client did while sending hello message.
• Session ID: server sends this newly generated id, that will be used in further communications. By this server can detect whether a session exist b/w webgate & server or not.

4. Key Exchange Phase: 

•  This phase is divided into 2 messages exchanged b/w client & server:
• SERVER KEY EXCHANGE
• CLIENT KEY EXCHANGE

Server key exchange - During this message exchange you will notice that while sending server hello, you see one more message along with it i.e. SERVER KEY EXCHANGE. This message is encrypted with server's private key and client decrypts it with the server's public key received with server's certificate.

• The SERVER KEY EXCHANGE Message is not mandatory to be sent by server, as it depends on the cipher suite selected for communication.
• DH_ANNON - for this cipher it will be sent
• RSA/MD5 - it will not be sent
• After this server key exchange, server hello is done. immediately after this from webgate side it is required to send CLIENT KEY EXCHANGE message. The data in this message is encrypted with server's public key.

Client key exchange -

• The purpose of sending this message is to share the master key, which client generates using the (client random number + server random number) encrypts it using the cipher suite selected & encrypts the whole message with public key shared by server in its certificate.

Note: 

• This above key exchange step is required so that to generate a master key that will be used as symmetric key b/w server & client for further data exchange.
• And to achieve this step we use asymmetric key, as we saw client used server public key for sending CLIENT KEY EXCHANGE Message while server used its private key to send SERVER KEY EXCHANGE Message.

5. FINISHED: at this point handshake process is done & now onwards client & server exchange the messages encrypted using the master key.


Note:

• It is possible that server will respond with error, if the list of cipher suite provided by webgate is not all supported not any one of it is supported or;
• The tls version provided by webgate is not supported by server.

6. Once client & server handshake is done successfully, after remaining INIT_NAP messages are excahnged b/w webgate & oam server.

7) Once above step is done successfully, than NAP channel is initialized b/w webgate & server. Basically this NAP channel in simple terms means a socket connection b/w webgate & server is established that will transmit the data over SSL.

Note: Once a NAP channel is initialized than for the requests been sent via this channel need not to do the SSL handshake again and again. It is a one time process per connection until unless that connections is to be refreshed or gets expired.


Hence the WEBGATE-OAM SSL Handshake finishes here.....



More Info: Related to SSL (nice article)
http://robertheaton.com/2014/03/27/how-does-https-actually-work/


Enjoy :-)