|Oracle® Fusion Middleware Administrator's Guide for Oracle Internet Directory
11g Release 1 (11.1.1)
Part Number E10029-04
|PDF · Mobi · ePub|
Password verifiers are the security credentials used to authenticate users to Oracle Internet Directory and other Oracle components. This chapter explains how Oracle Internet Directory centrally stores these password verifiers.
This chapter contains these topics:
When a user leaves a company or changes jobs, that user's privileges should change the same day to guard against misuse of old or unused accounts and privileges. Without centralized password administration, an administrator in a large enterprise with user accounts and passwords distributed over many databases may not be able to make the changes as quickly as good security requires.
Oracle Internet Directory centrally stores security credentials to make their administration easy for both end users and administrators. It stores:
Passwords for authenticating users to the directory itself
Password verifiers for authenticating users to other Oracle components
Users can store non-Oracle authentication credentials if the non-Oracle applications are directory enabled. These applications must create their own container under the Products entry.
Oracle Internet Directory stores a user's directory password in the
userPassword attribute. You can protect this password by storing it as a Base64 encoded string of a one-way hashed value by using one of Oracle Internet Directory's supported hashing algorithms. Storing passwords as one-way hashed values—rather than as encrypted values—more fully secures them because a malicious user can neither read nor decrypt them.
The default userPassword hashing algorithm for Oracle Internet Directory has been changed from MD4 to SHA. This default scheme is in effect for new installations only. All
userPassword attributes created after a new install are one-way hashed using SHA, then stored in Oracle Internet Directory.
When you perform an upgrade, the default hashing scheme in effect before upgrade is retained. For example, if the default scheme before the upgrade was MD4, then MD4 remains the default scheme after the upgrade. To ensure greater security of
userPasswords, change the default scheme to SHA immediately after the upgrade. When you change the default scheme to SHA, user login is unaffected. For greater security, require users to reset their passwords so that SHA values hash values are stored in Oracle Internet Directory.
Note:For even greater security, three variants of the more secure SHA-2 algorithm, as well as salted versions of those variants, are available, as of 11g Release 1 (126.96.36.199.0).
Oracle Internet Directory stores the user password in a reversible encrypted format in a configuration attribute called
orclrevpwd. This attribute is generated only if the attribute
orclpwdencryptionenable in the password policy entry is set to
orclrevpwd attribute is maintained securely within the server and cannot be queried.
This section contains these topics:
Oracle Internet Directory can protect a user's directory password by storing it in the
userPassword attribute as a one-way hashed value. You select the hashing algorithm you want to use. Storing passwords as one-way hashed values—rather than as encrypted values—more fully secures them because a malicious user can neither read nor decrypt them.
During authentication to a directory server, clients supply a password to the directory server in clear text. The directory server hashes this password by using the hashing algorithm specified in the DSE attribute
orclcryptoscheme. It then verifies it against the hashed password stored in the binding entry's
userPassword attribute. If the hashed password values match, then the server authenticates the user. If they do not match, then the server sends the user an "Invalid Credentials" error message.
For external users, Oracle Internet Directory generates the attribute
orclrevpwd during authentication. In particular this attribute is generated when clients authenticate using
ldapcompare on the user's cleartext password. If the attribute
orclrevpwd does not exist, then the Oracle Internet Directory server generates this attribute using the cleartext password provided for authentication. However this attribute is not generated if external users are authenticated against Oracle Internet Directory using
During installation, Oracle Identity Management 11g Installer sets the one-way hashing scheme for protecting user passwords to the directory to SHA. This value is stored in the
orclCryptoScheme attribute in the root DSE. You can change that value to any of the following hashing schemes:
SHA-1: Secure Hash Algorithm, which produces a 160-bit hash, longer than MD5. The algorithm is slightly slower than MD5, but the larger message digest makes it more secure against brute-force collision and inversion attacks. Potential vulnerabilities have been found in SHA-1
None: Passwords are stored in clear text.
Note:In the past Oracle Internet Directory supported the DES variant of UNIX Crypt. In 11g Release 1 (11.1.1) Oracle Internet Directory has the capability to understand the MD5 and Blowfish variants of UNIX Crypt. This means pre-hashed passwords using these other variants can be imported into Oracle Internet Directory as-is and will continue to work. However, selecting UNIX Crypt as
orclcryptoschemewill continue to only generate the DES variant of UNIX Crypt.
The following example changes the password hashing algorithm to SHA512 by using an LDIF file named
ldapmodify -D cn=orcladmin -q -h myhost -p 3060 -v -f my_ldif_file
The LDIF file,
dn: changetype: modify replace: orclcryptoscheme orclcryptoscheme: SHA512
Oracle components store both passwords and password verifiers in Oracle Internet Directory. This section contains these topics:
Oracle components can store their password values in Oracle Internet Directory as password verifiers. A password verifier is a hashed version of a clear text password, which is then encoded as a BASE64 encoded string.
SHA-1: Secure Hash Algorithm, which produces a 160-bit hash, longer than MD5. The algorithm is slightly slower than MD5, but the larger message digest makes it more secure against brute-force collision and inversion attacks.
During Oracle application installation, the Oracle Identity Management 11g Installer creates for that application a password verifier profile entry containing all the necessary password verification information. It places this entry, as shown in Figure 30-1, immediately below the application entry, which resides under the products entry, which, in turn, resides under the realm-specific Oracle Context.
This verifier profile entry is applicable to users in the specified realm only. For verifier generation to take effect, you must set the
orclcommonusersearchbase attribute in the common entry of the realm-specific Oracle context to the appropriate value.
Both the directory and Oracle components store the user password in the user entry, but in different attributes. Whereas the directory stores user passwords in the
userPassword attribute, Oracle components store user password verifiers in the
orclpassword attribute. Table 30-1 describes each of the attributes used by Oracle components.
Table 30-1 Attributes for Storing Password Verifiers in User Entries
Attribute for storing a password to an Oracle component when that password is the same as that used to authenticate the user to the directory, namely,
Several different applications can require the user to enter the same clear text password used for the directory, but each application may hash it with a different algorithm. In this case, the same clear text password can become the source of several different password verifiers.
This attribute is multivalued and can contain all the other verifiers that different applications use for this user's clear text password. If the
Attribute for storing a password to an Oracle component when that password is different from that used to authenticate the user to the directory, namely,
Attribute for storing only the 03LOGON verifier for enterprise users. The 03LOGON verifier is synchronized with the
When Oracle Internet Directory is installed, a database security profile entry is created by default in the Root Oracle Context. The presence of this entry triggers the generation of 03LOGON verifiers for user entries associated with the
Each of these attribute types has
appID as an attribute subtype. This attribute subtype uniquely identifies a particular application. For example, the
appID can be the
ORCLGUID of the application entry. This attribute subtype is generated during application installation.
In Figure 30-2, various Oracle components store their password verifiers in Oracle Internet Directory. Oracle Single Sign-On uses the same password as that for the directory, and hence stores it in the
authPassword attribute.The other applications use different passwords and hence store their verifiers in
The following is an example of an application-specific verifier profile entry. Any application that chooses not to use the common verifier framework must create its own verifier profile entry, similar to the one given in the following example. The
orclappid is set to the GUID of the application container and it will also be used as a subtype in the verifier attributes
dn: cn=IFSVerifierProfileEntry,cn=IFS,cn=Products,cn=OracleContext,o=Oracle,dc=com objectclass:top objectclass:orclpwdverifierprofile cn:IFSVerifierProfileEntry orclappid:8FF2DFD8203519C0E034080020C34C50 orclpwdverifierparams;authpassword: crypto:SASL/MDS $ realm:dc=com orclpwdverifierparams;orclpasswordverifier: crypto:ORCLLM orclpwdverifierparams;authpassword: crypto:ORCLWEBDAV $ realm:dc=com $ usernameattribute: mail $ usernamecase: lower $ nodomain: TRUE
SASL/MD5 and ORCLWEBDAV verifiers are generated by using user name, realm, and password. The user name attribute to be used can be specified in the verifier profile entry. The case of the user name can also be specified as either upper or lower. The ORLWEBDAV verifier is generated by appending the name of the identity management realm to the user name. If this is not required, then the verifier profile entry must specify
In the previous example, ORCLWEBDAV verifier is generated by using the value of the
Figure 30-2 Authentication Model
To save you from having to create a profile for each Oracle component, and to enable sharing of password verifiers across all components, Oracle Internet Directory provides a default set of password verifiers. The default verifier types are MD5, MD5-IFS (SASL/MD5 with the user name set to the value of the nickname attribute and realm = Authorized_Users), WEBDAV, ORCLLM, and ORCLNT.
Two profile entries are required: one for applications using personal identification numbers (PINs), which use numeric values only, and another for applications using alphanumeric passwords.
The verifiers for PIN-based applications—for example, the voice mail application in OracleAS Unified Messaging—are stored in the
orclpasswordverifier;orclcommonpin attribute. The subtype
orclcommonpin is used to distinguish numeric PINs from alphanumeric passwords. Any application that uses numeric PINs can directly query or compare against the attribute
The verifiers for alphanumeric password-based applications can be stored in either:
authpassword;orclcommonpwd attribute—If an application requires its verifier to be synchronized with the
orclpasswordverifier;orclcommonpwd attribute—If synchronization with the
userpassword attribute is not required
orclcommonpwd is used to distinguish alphanumeric passwords from numeric PINs. The verifier attributes subtyped by orclcommonpwd can be queried against.
These profile entries also contain the list of subscribed applications and these are specified as values in the
uniquemember attribute in the profile entries. By default, the DN of the Oracle Single Sign-On identity is one of the subscribed applications. This means that Oracle Single Sign-On is a proxy member for all its partner applications. All applications not based on Oracle Single Sign-On must add their identities (DNs) to the
uniquemember attribute in the appropriate profile entry.
The following is an example of the profile entries.
Cn=defaultSharedPwdProfileEntry, cn=common, cn=products, cn=oraclecontext Objectclass: orclpwdverifierprofile Objectclass: orclcommonpwdprofile Cn: defaultSharedPwdProfileEntry Orclappid: orclcommonpwd Orclpwdverifierparams;authpassword: crypto:SASL/MD5 $ realm:Authorized_Users Orclpwdverifierparams;authpassword: crypto:ORCLWEBDAV $ realm:Authorized_Users Orclpwdverifierparams;authpassword: crypto:ORCLLM Orclpwdverifierparams;authpassword: crypto:ORCLNT Orclpwdverifierparams;orclpasswordverifier: crypto:SSHA Uniquemember: cn=SSO,cn=Products,cn=OracleContext Uniquemember: cn=IFS,cn=Products,cn=OracleContext Cn=defaultSharedPINProfileEntry, cn=common, cn=products, cn=oraclecontext Objectclass: orclpwdverifierprofile Objectclass: orclcommonpwdprofile Cn: defaultSharedPinProfileEntry Orclappid: orclcommonpin Orclpwdverifierparams;orclpasswordverifier: crypto:MD5 Orclpwdverifierparams;orclpasswordverifier: crypto:SSHA Uniquemember: cn=SSO,cn=Products,cn=OracleContext Uniquemember: cn=Unified Messaging,cn=Products,cn=OracleContext
For PIN-based applications,
authpassword is not an option. Such applications use the
Figure 30-3 shows an example of password verification for an Oracle component. In this example, the Oracle component stores its password verifiers in the directory.
The user tries to log in to an application by entering a user name and a clear text password.
The application sends the clear text password to the directory server. If the application stores password verifiers in the directory, then the application requests the directory server to compare this password value with the corresponding one in the directory.
The directory server:
Generates a password verifier by using the hashing algorithm specified for the particular application
Compares this password verifier with the corresponding password verifiers in the directory. For the compare operation to be successful, the application must provide its
appID as the subtype of the verifier attribute. For example:
ldapcompare -p 3060 -D "DN_of_the_appplication_entity" -q \ -b "DN_of_the_user" -a orclpasswordverifier; appID \ -v password_of_the_user
Notifies the application of the results of the compare operation.
Depending on the message from the directory server, the application either authenticates the user or not.
If an application does not use the compare operation, then it:
Hashes the clear text password entered by the user
Retrieves from the directory the hashed value of the clear text password as entered by the user
Initiates a challenge to the user to which the client responds. If the response is correct, then the application authenticates the user.
To view and modify an application's password verifiers:
Invoke Oracle Directory Services Manager and connect to the Oracle Internet Directory server as described in Section 7.4.5, "Invoking Oracle Directory Services Manager."
From the task selection bar, select Security.
Expand Password Verifier in the left pane. All of the password verifiers appear in the left pane.
Select the password verifier you want to view. The right pane displays the Password Verifier Profile tab page.
You can modify the hashing algorithm used to generate a password verifier. In the Password Verifier Profile dialog box, specify the hashing algorithm in the Oracle Password Parameters field. The syntax is:
For example, if you are using the ORCLLM hashing algorithm, then you would enter:
If you are using SASL/MD5, for example, you can enter the following:
crypto:SASL/MD5 $ realm:dc=com
You can view and modify password verifier profiles by using command-line tools.
ldapmodify -D "cn=orcladmin" -q -p 3060 -h my_host -v -f file.ldif
dn: cn=MyAppVerifierProfileEntry,cn=MyApp,cn=Products,cn=OracleContext, o=my_company,dc=com changetype: modify replace: orclPwdVerifierParams orclPwdVerifierParams;authPassword: crypto:SASL/MD5 $ realm:dc=com
The password verifiers described previously are static password verifiers. That is, they are generated with preconfigured parameters, typically during application installation. Some applications, including Oracle Calendar, Oracle Email, and Oracle Wireless and Voice, require Oracle Internet Directory to generate dynamic password verifiers.
Oracle Internet Directory generates a dynamic password verifier when an application requests one. Dynamic verifiers are based on application parameters that are not available until run time.
In order to generate a dynamic password verifier, Oracle Internet Directory needs a user password that was previously stored in a reversible encrypted format. Oracle Internet Directory stores such values in the configuration attributes
orclunsyncrevpwd. Encrypted values based on
userpassword are stored in the parameter
orclrevpwd. Encrypted values based on passwords other than
userpassword, such as the numeric PINs used by Oracle Calendar, are stored in the parameter
If you are deploying applications that use
userpassword and that need dynamic password verifiers, you must ensure that Oracle Internet Directory generates the
orclrevpwd attribute. Oracle Internet Directory generates the attribute
orclrevpwd when you provision a user if the attribute
orclpwdencryptionenable in the realm password policy entry is set to
1. Therefore, you must set
1 before you provision users.
$ ldapsearch -p port -q -D "cn=orcladmin" \ -b "cn=default,cn=pwdPolicies,cn=Common,cn=Products,cn=OracleContext" \ -s base "objectclass=*"
orclpwdencryptionenable is not listed or is equal to
0, set it to
1 by using ldapmodify with an LDIF file similar to this:
dn: cn=DefaultSharedPinProfileEntry,cn=Common,cn=Products,cn=Oraclecontext cn: DefaultSharedPinProfileEntry orclappid: orclpwdencryptionenable orclpwdencryptionenable: 1
Alternatively, if users were provisioned before you set
orclpwdencryptionenable, all users must reset their user passwords to trigger the generation of the encrypted value.
If you are deploying applications that use a numeric PIN and that need dynamic password verifiers, you must ensure that Oracle Internet Directory can use the crypto type
3DES in order to generate the value stored in
orclunsyncrevpwd. You must specify
3DES as a value of the attribute
orclpwdverifierparams;orclpasswordverifier in the common verifier profile entry under the root oracle context. The default DN of this entry is
cn=DefaultSharedPINProfileEntry,cn=Common,cn=Products, cn=OracleContext. To set the value, you would use the following LDIF file:
dn: cn=DefaultSharedPinProfileEntry,cn=Common,cn=Products,cn=Oraclecontext cn: DefaultSharedPinProfileEntry orclappid: orclcommonpin orclpwdverifierparams;orclpasswordverifier: crypto:MD5 orclpwdverifierparams;orclpasswordverifier: crypto:3DES