Set-AuthenticodeSignature

Module:

Microsoft.PowerShell.Security

Adds an Authenticode signature to a PowerShell script or other file.

Syntax

Set-AuthenticodeSignature
   [-Certificate] <X509Certificate2>
   [-IncludeChain <String>]
   [-TimestampServer <String>]
   [-HashAlgorithm <String>]
   [-Force]
   [-FilePath] <String[]>
   [-WhatIf]
   [-Confirm]
   [<CommonParameters>]

Set-AuthenticodeSignature
   [-Certificate] <X509Certificate2>
   [-IncludeChain <String>]
   [-TimestampServer <String>]
   [-HashAlgorithm <String>]
   [-Force]
   -LiteralPath <String[]>
   [-WhatIf]
   [-Confirm]
   [<CommonParameters>]

Set-AuthenticodeSignature
   [-Certificate] <X509Certificate2>
   [-IncludeChain <String>]
   [-TimestampServer <String>]
   [-HashAlgorithm <String>]
   [-Force]
   -SourcePathOrExtension <String[]>
   -Content <Byte[]>
   [-WhatIf]
   [-Confirm]
   [<CommonParameters>]

Description

The Set-AuthenticodeSignature cmdlet adds an Authenticode signature to any file that supports Subject Interface Package (SIP).

In a PowerShell script file, the signature takes the form of a block of text that indicates the end of the instructions that are executed in the script. If there is a signature in the file when this cmdlet runs, that signature is removed.

Examples

Example 1 - Sign a script using a certificate from the local certificate store

These commands retrieve a code-signing certificate from the PowerShell certificate provider and use it to sign a PowerShell script.

$cert=Get-ChildItem -Path Cert:\CurrentUser\My -CodeSigningCert
$signingParameters = @{
    FilePath      = 'PsTestInternet2.ps1'
    Certificate   = $cert
    HashAlgorithm = 'SHA256'
}
Set-AuthenticodeSignature @signingParameters

The first command uses the Get-ChildItem cmdlet and the PowerShell certificate provider to get the certificates in the Cert:\CurrentUser\My subdirectory of the certificate store. The Cert: drive is the drive exposed by the certificate provider. The CodeSigningCert parameter, which is supported only by the certificate provider, limits the certificates retrieved to those with code-signing authority. The command stores the result in the $cert variable.

The second command defines the $signingParameters variable as a HashTable with the parameters for the Set-AuthenticodeSignature cmdlet to sign the PSTestInternet2.ps1 script. It uses the FilePath parameter to specify the name of the script, the Certificate parameter to specify that the certificate is stored in the $cert variable, and the HashAlgorithm parameter to set the hashing algorithm to SHA256.

The third command signs the script by splatting the parameters defined in $signingParameters.

Note

Using the CodeSigningCert parameter with Get-ChildItem only returns certificates that have code-signing authority and contain a private key. If there is no private key, the certificates cannot be used for signing.

Example 2 - Sign a script using a certificate from a PFX file

These commands use the Get-PfxCertificate cmdlet to load a code signing certificate. Then, use it to sign a PowerShell script.

$cert = Get-PfxCertificate -FilePath C:\Test\Mysign.pfx
$signingParameters = @{
    FilePath      = 'ServerProps.ps1'
    Certificate   = $cert
    HashAlgorithm = 'SHA256'
}
Set-AuthenticodeSignature @signingParameters

The first command uses the Get-PfxCertificate cmdlet to load the C:\Test\MySign.pfx certificate into the $cert variable.

The second command defines the $signingParameters variable as a HashTable with the parameters for the Set-AuthenticodeSignature cmdlet to sign the ServerProps.ps1 script. It uses the FilePath parameter to specify the name of the script, the Certificate parameter to specify that the certificate is stored in the $cert variable, and the HashAlgorithm parameter to set the hashing algorithm to SHA256.

The third command signs the script by splatting the parameters defined in $signingParameters.

If the certificate file is password protected, PowerShell prompts you for the password.

Example 3 - Add a signature that includes the root authority

This command adds a digital signature that includes the root authority in the trust chain, and it is signed by a third-party timestamp server.

$signingParameters = @{
    FilePath      = 'C:\scripts\Remodel.ps1'
    Certificate   = $cert
    HashAlgorithm = 'SHA256'
    IncludeChain  = 'All'
    TimestampServer = 'http://timestamp.fabrikam.com/scripts/timstamper.dll'
}
Set-AuthenticodeSignature @signingParameters

The first command defines the $signingParameters variable as a HashTable with the parameters for the Set-AuthenticodeSignature cmdlet to sign the script. It uses the FilePath parameter to specify the path to the script, the Certificate parameter to specify that the certificate is stored in the $cert variable, and the HashAlgorithm parameter to set the hashing algorithm to SHA256. It uses the IncludeChain parameter to include all of the signatures in the trust chain, including the root authority. It also uses the TimeStampServer parameter to add a timestamp to the signature. This prevents the script from failing when the certificate expires.

The second command signs the script by splatting the parameters defined in $signingParameters.

Parameters

-Certificate

Specifies the certificate that will be used to sign the script or file. Enter a variable that stores an object representing the certificate or an expression that gets the certificate.

To find a certificate, use Get-PfxCertificate or use the Get-ChildItem cmdlet in the Certificate Cert: drive. If the certificate is not valid or does not have code-signing authority, the command fails.

Type:	X509Certificate2
Position:	1
Default value:	None
Required:	True
Accept pipeline input:	False
Accept wildcard characters:	False

-Confirm

Prompts you for confirmation before running the cmdlet.

Type:	SwitchParameter
Aliases:	cf
Position:	Named
Default value:	False
Required:	False
Accept pipeline input:	False
Accept wildcard characters:	False

-Content

This parameter appears in the syntax listing because it is defined in the base class that Set-AuthenticodeSignature is derived from. However, support for this parameter is not implemented in Set-AuthenticodeSignature.

Type:	Byte[]
Position:	Named
Default value:	None
Required:	True
Accept pipeline input:	True
Accept wildcard characters:	False

-FilePath

Specifies the path to a file that is being signed.

Type:	String[]
Position:	1
Default value:	None
Required:	True
Accept pipeline input:	True
Accept wildcard characters:	False

-Force

Allows the cmdlet to append a signature to a read-only file. Even using the Force parameter, the cmdlet cannot override security restrictions.

Type:	SwitchParameter
Position:	Named
Default value:	False
Required:	False
Accept pipeline input:	False
Accept wildcard characters:	False

-HashAlgorithm

Specifies the hashing algorithm that Windows uses to compute the digital signature for the file.

The default is SHA1. Files that are signed with a different hashing algorithm might not be recognized on other systems. Which algorithms are supported depends on the version of the operating system.

For a list of possible values, see HashAlgorithmName Struct.

Type:	String
Position:	Named
Default value:	Null
Required:	False
Accept pipeline input:	False
Accept wildcard characters:	False

-IncludeChain

Determines which certificates in the certificate trust chain are included in the digital signature. NotRoot is the default.

Valid values are:

• Signer: Includes only the signer's certificate.
• NotRoot: Includes all of the certificates in the certificate chain, except for the root authority.
• All: Includes all the certificates in the certificate chain.

Type:	String
Position:	Named
Default value:	NotRoot
Required:	False
Accept pipeline input:	False
Accept wildcard characters:	False

-LiteralPath

Specifies the path to a file that is being signed. Unlike FilePath, the value of the LiteralPath parameter is used exactly as it is typed. No characters are interpreted as wildcards. If the path includes escape characters, enclose it in single quotation marks. Single quotation marks tell PowerShell not to interpret any characters as escape sequences.

Type:	String[]
Aliases:	PSPath
Position:	Named
Default value:	None
Required:	True
Accept pipeline input:	True
Accept wildcard characters:	False

-SourcePathOrExtension

This parameter appears in the syntax listing because it is defined in the base class that Set-AuthenticodeSignature is derived from. However, support for this parameter is not implemented in Set-AuthenticodeSignature.

Type:	String[]
Position:	Named
Default value:	None
Required:	True
Accept pipeline input:	True
Accept wildcard characters:	False

-TimestampServer

Uses the specified time stamp server to add a time stamp to the signature. Type the URL of the time stamp server as a string.

The time stamp represents the exact time that the certificate was added to the file. A time stamp prevents the script from failing if the certificate expires because users and programs can verify that the certificate was valid at the time of signing.

Type:	String
Position:	Named
Default value:	None
Required:	False
Accept pipeline input:	False
Accept wildcard characters:	False

-WhatIf

Shows what would happen if the cmdlet runs. The cmdlet is not run.

Type:	SwitchParameter
Aliases:	wi
Position:	Named
Default value:	False
Required:	False
Accept pipeline input:	False
Accept wildcard characters:	False

Inputs

String

You can pipe a string that contains the file path to this cmdlet.

Outputs

Signature

This cmdlet returns a Signature object representing the value it set.

Related Links

• Get-AuthenticodeSignature
• Get-ExecutionPolicy
• Get-PfxCertificate
• Set-ExecutionPolicy
• about_Execution_Policies
• about_Signing