PSCredentialStore/src/Item/Get-CredentialStoreItem.ps1

function Get-CredentialStoreItem {
    <#
    .SYNOPSIS
        Returns the Credential from a given remote host item.

    .DESCRIPTION
        Return the credential as PSCredential object.


    .PARAMETER RemoteHost
        Specify the host, for which you would like to change the credentials.

    .PARAMETER Identifier
            Provide a custom identifier to the given remote host key. This enables you to store multiple credentials
            for a single remote host entry. For example ad/sys1, ftp/sys1, mssql/sys1

    .PARAMETER Path
        Define a custom path to a shared CredentialStore.

    .PARAMETER Shared
        Switch to shared mode with this param. This enforces the command to work with a shared CredentialStore which
        can be decrypted across systems.

    .INPUTS
        [None]

    .OUTPUTS
        [System.Management.Automation.PSCredential]

    .EXAMPLE
        $myCreds = Get-CredentialStoreItem -Path "C:\TMP\mystore.json" -RemoteHost "esx01.myside.local"

    .NOTES
        - File Name   : Get-CredentialStoreItem.ps1
        - Author      : Messing - marco.blessing@googlemail.com
        - Requires    :

    .LINK
        https://github.com/OCram85/PSCredentialStore
    #>

    [CmdletBinding(DefaultParameterSetName = "Private")]
    [OutputType([PSCredential])]
    param(
        [Parameter(Mandatory = $true, ParameterSetName = "Shared")]
        [Parameter(Mandatory = $true, ParameterSetName = "Private")]
        [ValidateNotNullOrEmpty()]
        [string]$RemoteHost,

        [Parameter(Mandatory = $false, ParameterSetName = "Shared")]
        [Parameter(Mandatory = $false, ParameterSetName = "Private")]
        [ValidateNotNullOrEmpty()]
        [string]$Identifier,

        [Parameter(Mandatory = $true, ParameterSetName = "Shared")]
        [switch]$Shared,

        [Parameter(Mandatory = $false, ParameterSetName = "Shared")]
        [ValidateNotNullOrEmpty()]
        [string]$Path
    )

    begin {
        # Set the CredentialStore for private, shared or custom mode.
        Write-Debug ("ParameterSetName: {0}" -f $PSCmdlet.ParameterSetName)
        if ($PSCmdlet.ParameterSetName -eq "Private") {
            $Path = Get-DefaultCredentialStorePath
        }
        elseif ($PSCmdlet.ParameterSetName -eq "Shared") {
            if (!($PSBoundParameters.ContainsKey('Path'))) {
                $Path = Get-DefaultCredentialStorePath -Shared
            }
        }
    }

    process {
        if ($Identifier -ne "") {
            $CredentialName = $RemoteHost = "{0}/{1}" -f $Identifier, $RemoteHost
        }
        else {
            $CredentialName = $RemoteHost
        }

        if (Test-CredentialStore -Shared -Path $Path) {
            $CS = Get-CredentialStore -Shared -Path $Path
            $CSMembers = Get-Member -InputObject $CS
            # Let's first check if the given remote host exists as object property
            if (($CSMembers.MemberType -eq "NoteProperty") -and ($CSMembers.Name -contains $CredentialName)) {
                if ($null -eq $CS.PfxCertificate) {
                    $Cert = Get-CSCertificate -Type $CS.Type -Thumbprint $CS.Thumbprint
                }
                else {
                    $Cert = Get-PfxCertificate -FilePath $CS.PfxCertificate -ErrorAction Stop
                }
                $DecryptedKey = $Cert.PrivateKey.Decrypt(
                    [Convert]::FromBase64String($CS.$CredentialName.EncryptedKey),
                    [System.Security.Cryptography.RSAEncryptionPadding]::Pkcs1
                )

                if (! $ExpandOutput.isPresent) {
                    [PSCredential]::new(
                        $CS.$CredentialName.User,
                        ($CS.$CredentialName.Password | ConvertTo-SecureString -Key $DecryptedKey)
                    )
                }
            }
            else {
                $MsgParams = @{
                    ErrorAction = "Stop"
                    Message     = "Could not find credentials for the given remote host: {0}" -f $RemoteHost
                }
                Write-Error @MsgParams
            }
        }
        else {
            $MsgParams = @{
                ErrorAction = "Stop"
                Message     = "The given credential store ({0}) does not exist!" -f $Path
            }
            Write-Error @MsgParams
        }
    }

    end {

    }

}