Publisher Configuration Files

A publisher configuration file is an XML file that globally redirects applications and assemblies from using one version of a side-by-side assembly to another version of the same assembly. Typically, the publisher of the assembly issues a compatible update or security fix on a per-assembly basis by issuing a publisher configuration file to be installed along with a service pack update. This is referred to as publisher configuration. For more information about this type of configuration see Publisher Configuration.

Publisher configuration files have the following elements and attributes. For a complete listing of the XML schema, see Publisher Configuration File Schema.

Element	Attributes	Required
assembly		Yes
	manifestVersion	Yes
assemblyIdentity		Yes
	type	Yes
	name	Yes
	language	No
	processorArchitecture	No
	version	Yes
	publicKeyToken	No
dependency		No
dependentAssembly		No
bindingRedirect		Yes
	oldVersion	Yes
	newVersion	Yes

File Location

Publisher configuration files must be installed in the WinSxS folder. They are commonly installed as a separate file but publisher configuration files can also be included as a resource in a DLL. A publisher configuration file cannot be included as a resource in an EXE file. An EXE file may include an application manifest as a resource.

File Name Syntax

The file name of a publisher configuration file has the form policy.major.minor.assemblyname where major and minor refer to the major and minor parts of the assembly version that is being affected. The assemblyname refers to the name of the assembly.

For example, a publisher configuration file for version 6.0 of the Microsoft.Windows.Common-Controls assembly would have the following name:

policy.6.0.Microsoft.Windows.Common-Controls

Do not use policy configuration files to increment the major or minor version of an assembly. For example, do not redirect version 6.0.0.0 to 7.0.0.0 or 6.1.0.0. When an application references an assembly version, such as 6.0.0.0, side-by-side checks for the presence of any policy configuration files with the specified major and minor versions, e.g. 6.0. The application is then redirected to another version of the assembly, for example 6.0.1.0. If a publisher configuration file increments the major or minor version of an assembly, subsequent redirection of the assembly may require issuing multiple policy configuration files.

Elements

assembly

A container element. Its first subelement must be an assemblyIdentity. Required.

The assembly element must be in the namespace urn:schemas-microsoft-com:asm.v1. Child elements of the assembly must also be in this namespace, by inheritance or by tagging.

The assembly element has the following attributes.

Attribute	Description
manifestVersion	The manifestVersion attribute must be set to 1.0.

assemblyIdentity

Describes and uniquely identifies a side-by-side assembly.

As the first subelement of an assembly element, the assemblyIdentity describes the side-by-side assembly that is having one or more of its assembly dependencies changed. The publisher configuration file redirects the dependencies of the assembly identified. For example, the following assemblyIdentity indicates that the publisher configuration file affects the dependencies of the x86 Microsoft.Windows.Pop 6.0.0.0 assembly.

<assemblyIdentity 
     type="win32-policy" 
     publicKeyToken="0000000000000000" 
     name="policy.6.0.Microsoft.Windows.Pop" 
     version="2.1.0.0" 
     processorArchitecture="x86"/>

As the first subelement of a dependentAssembly element, assemblyIdentity describes a side-by-side assembly dependency. The publisher configuration file reconfigures the identity of this required side-by-side assembly. The change is specified in a bindingRedirect. For example, the following assemblyIdentity changes any dependency on Microsoft.Windows.SampleAssembly version 2.0.0.0 to a dependency on Microsoft.Windows.SampleAssembly version 2.0.1.0.

<dependency>
      <dependentAssembly>
         <assemblyIdentity 
type="win32" 
name="Microsoft.Windows.SampleAssembly"  
processorArchitecture="x86"
publicKeyToken="0000000000000000"/>
         <bindingRedirect oldVersion="2.0.0.0" newVersion="2.0.1.0"/>
      </dependentAssembly>
</dependency>

The assemblyIdentity element has the following attributes. It has no sub-elements.

Attribute	Description
type	Specifies the assembly type. Required. In the assemblyIdentity for the assembly being affected, the value of the type attribute must be set to win32-policy. The value win32-policy must be in all lowercase letters. In the assemblyIdentity for the changing assembly dependency, the value of the type attribute must be set to win32. The value win32 must be in all lowercase letters.
name	Uniquely names an assembly. Required. In the assemblyIdentity for the assembly being affected, name has the form policy.major.minor.assemblyname where major and minor refer to the major and minor parts of the assembly version. In the assemblyIdentity for the changing assembly dependency, name has the form Organization.Division.Name. For example, Microsoft.Windows.MysampleApp.
language	Identifies the language of the assembly. Optional. In the assemblyIdentity for the assembly being affected, if the assembly is language-specific, specify the DHTML language code. If the assembly is for worldwide use (language neutral), omit this attribute. In the assemblyIdentity for the changing assembly dependency, if the assembly is language-specific, specify the DHTML language code. If the assembly is for worldwide use (language neutral) set the value as "*".
processorArchitecture	Specifies the processor running the application.
version	Specifies the assembly version. Use four-part version syntax: mmmm.nnnn.oooo.pppp Required only in the DEF-context assemblyIdentity. Do not specify the version attribute in the REF-context assemblyIdentity.
publicKeyToken	A 16-character hexadecimal string representing the last 8 bytes of the SHA-1 hash of the public key under which the assembly is signed. The public key used to sign the catalog must be 2048 bits or greater. A publicKeyToken is required for all shared side-by-side assemblies. The publicKeyToken used for the publisher configuration file should be the same key used for the signed assembly. Publisher configuration files can be signed using the same tools as used with assemblies, see Assembly Signing Example and Creating Signed Files and Catalogs.

dependency

An optional container element for at least one dependentAssembly. It has no attributes.

dependentAssembly

Every dependentAssembly must be inside exactly one dependency. A dependentAssembly has no attributes. The first subelement of dependentAssembly must be an assemblyIdentity for the side-by-side assembly being reconfigured by the publisher configuration.

bindingRedirect

The bindingRedirect element contains redirection information for the binding of the assembly.

This element has the attributes shown in the following table.

Attribute	Description
oldVersion	Specifies the assembly version being overridden and redirected. Use the four-part version syntax nnnnn.nnnnn.nnnnn.nnnnn. Specify a range of versions by a dash with no spaces. For example, 2.14.3.0 or 2.14.3.0 2.16.0.0. Required.
newVersion	Specifies the replacement assembly version. Use four-part version syntax nnnnn.nnnnn.nnnnn.nnnnn.

Remarks

Publisher configuration files do not specify files. Note that language-specific policy files are separate from the publisher configuration file.

Example

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
<assemblyIdentity type="win32-policy" publicKeyToken="0000000000000000" name="policy.6.0.Proseware.Research.SampleAssembly" version="1.0.1.0" language="en-us" processorArchitecture="x86"/>
<dependency>
<dependentAssembly>
<assemblyIdentity type="win32" publicKeyToken="0000000000000000" name="Proseware.Research.SampleAssembly" language="en-us" processorArchitecture="x86"/>
<bindingRedirect oldVersion="1.0.0.0" newVersion="1.0.1.0"/>
</dependentAssembly>
</dependency>
</assembly>