There are numerous authentication methods that are supported by SharePoint Server 2010. Through authentication the identity of a user can be validated. Once that occurs the process of authorization will also determine which sites, what types of content, and which of the features available a given user has authority to access. SharePoint Server 2010 can be considered a type of distributed application. There are three tiers that it is divided into which are all important to consider when determining your authentication strategy:
- Application server
- Back end database
- Front end web server
Each of these tiers offers a sub-system and corresponding authentication. A user has to be authorized before they can go from one tier to the next. The provider has control over what levels of access each user has. Those providers offer various software elements that are used to support a specific method of authentication. With SharePoint 2010 you can use a classic mode of authentication or a claims based method. If you are upgrading from Microsoft Office SharePoint Server 2007 Microsoft documentation will recommended you use the classic mode, personally I think it's advisable to just go claims since you can use the identity generation service to generate Windows identities. If you plan to use a forms based authentication or one that is SAML token based you should use the claims based method. This is because the classic mode authentication will only support Windows authentication.
There are several methods of authentication that can be supported by SharePoint Server 2010. As you explore the basics of them you can decide what will work best for your organization. There are three:
This is the standard method of authentication. There are many methods that fall into this particular category. They include:
- Anonymous This allows users to find and access resources from public areas of websites. They don’t have to provide any credentials for authentication to do so.
- Basic This requires a user to have account credentials that have been assigned ala Windows. There is a web browser that is enabled to provide such credentials when someone makes a request. The credentials of users aren’t encrypted but sent across the network as clear-text. Therefore it isn’t recommended for the use of basic authentication to be used on any connection that isn’t secure. Always use SSL encrypting for additional security.
- Digest This type of authentication is very similar in function to basic authentication. However, it offers a much higher level of security with it. The credentials are encrypted as they are sent across a network. The username and password can’t be deciphered along the way. Valid credentials must be given by a user that belong to the secret password string.
- Certificates This offers an exchange of the public key certifications. The use of SSL encryption is used. These certificates are issued by a Certificate Authority. They have to fit the Public Key Infrastructure. This can be done by selecting Windows authentication in the Central Administration area. Once SSL is enabled then the configured certification can be obtained from Certificate Authority.
- NTLM This is a requirement for any network that receives requests for authentication from client computers which don’t support Kerberos authentication. NTLM is secure and it allows for credentials of users to be encrypted before they are transmitted. Windows NT Server, Windows 2003 Server WorkGroup, and Active Directory use NTLM authentication. It may be the default and need to be disabled if you don’t want to use it.
- Negotiate With negotiate authentication for either NTLM or Kerberos, they client has to choose one of them. The default is Kerberos. The client application has to provide a Service Principal Name and a User Principal Name for the account. When such information can’t be offered then NTLM has to be used for authentication.
This type of authentication offers support for management systems that need to make identifications. They aren’t based on Windows because they make it possible to work with identity management systems. These use the MembershipProvider interface. This includes:
- Custom membership providers
- Lightweight Directory Access Protocol
- SQL Database
This based on ASP.NET as well as role provider authentication. With SharePoint 2010 it is only able to be used when claims based authentication is used. Forms Based Authentication can be used to be able to authenticate other user accounts too when connected to Microsoft SQL Server database. You need to register the membership provider in the Web.config file in order to use this type of authentication.
SAML Token Based
This type of authentication is claims based. It is created to support a Windows Identity Foundation. This is a set of .NET framework entities used for the implementation of claims based identity. They include:
- 3rd Party identity providers
- Active Directory Federation Services 2.0
- Windows Live ID
Next, we are going to be talking about user management in this SharePoint security series.