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Powershell使用密碼或字串加密文字文件

tag-icon • tag-icon command-line powershell encryption passwords
Powershell使用密碼或字串加密文字文件

我正在運行具有命令提示字元存取權限的共用計算機，我希望能夠使用唯一的使用者識別密碼從 powershell 腳本加密和解密文字檔案。這樣，沒有該密碼就無法開啟該檔案。我嘗試使用該模組，但是似乎需要一個叫做憑證的東西。我想要的只是一個 powershell 腳本，可以用類似的東西來呼叫-Encrypt -File "Path\To\File" -Password -"12345"（以及類似的東西來解密它）。存在這樣的工具嗎？如果沒有，我該怎麼做呢？

答案1

以下 PowerShell 可以滿足您的需求。 （來源*)

描述：

此 PowerShell 模組包含 3 個 cmdlet，用於建立 AES 金鑰、加密檔案和解密檔案。

用法範例：

#Create Key 
$key = New-CryptographyKey -Algorithm AES 
 
#Encrypt the file 
Protect-File '.\secrets.txt' -Algorithm AES -Key $key -RemoveSource 
 
#Decrypt the file 
Unprotect-File '.\secrets.txt.AES' -Algorithm AES -Key $key -RemoveSource

The full module code:

function New-CryptographyKey()
{
<#
.SYNOPSIS 
Generates a random cryptography key.

.DESCRIPTION
Generates a random cryptography key based on the desired key size.

.PARAMETER Algorithm
Algorithm to generate key for.

.PARAMETER KeySize
Number of bits the generated key will have.

.PARAMETER AsPlainText
Returns a String instead of SecureString.

.OUTPUTS
System.Security.SecureString. New-CryptographyKey return the key as a SecureString by default.
System.String. New-CryptographyKey will return the key in plain text as a string if the -AsPlainText parameter is specified.

.EXAMPLE
$key = New-CryptographyKey
This example generates a random 256-bit AES key and stores it in the variable $key.

.NOTES
Author: Tyler Siegrist
Date: 9/22/2017
#>
[CmdletBinding()]
[OutputType([System.Security.SecureString])]
[OutputType([String], ParameterSetName='PlainText')]
Param(
    [Parameter(Mandatory=$false, Position=1)]
    [ValidateSet('AES','DES','RC2','Rijndael','TripleDES')]
    [String]$Algorithm='AES',
    [Parameter(Mandatory=$false, Position=2)]
    [Int]$KeySize,
    [Parameter(ParameterSetName='PlainText')]
    [Switch]$AsPlainText
)
    Process
    {
        try
        {
            $Crypto = [System.Security.Cryptography.SymmetricAlgorithm]::Create($Algorithm)
            if($PSBoundParameters.ContainsKey('KeySize')){
                $Crypto.KeySize = $KeySize
            }
            $Crypto.GenerateKey()
            if($AsPlainText)
            {
                return [System.Convert]::ToBase64String($Crypto.Key)
            }
            else
            {
                return [System.Convert]::ToBase64String($Crypto.Key) | ConvertTo-SecureString -AsPlainText -Force
            }
        }
        catch
        {
            Write-Error $_
        }
        
    }
}

Function Protect-File
{
<#
.SYNOPSIS 
Encrypts a file using a symmetrical algorithm.

.DESCRIPTION
Encrypts a file using a symmetrical algorithm.

.PARAMETER FileName
File(s) to be encrypted.

.PARAMETER Key
Cryptography key as a SecureString to be used for encryption.

.PARAMETER KeyAsPlainText
Cryptography key as a String to be used for encryption.

.PARAMETER CipherMode
Specifies the block cipher mode to use for encryption.

.PARAMETER PaddingMode
Specifies the type of padding to apply when the message data block is shorter than the full number of bytes needed for a cryptographic operation.

.PARAMETER Suffix
Suffix of the encrypted file to be removed.

.PARAMETER RemoveSource
Removes the source (decrypted) file after encrypting.

.OUTPUTS
System.IO.FileInfo. Protect-File will return FileInfo with the SourceFile, Algorithm, Key, CipherMode, and PaddingMode as added NoteProperties

.EXAMPLE
Protect-File 'C:\secrets.txt' $key
This example encrypts C:\secrets.txt using the key stored in the variable $key. The encrypted file would have the default extension of '.AES' and the source (decrypted) file would not be removed.

.EXAMPLE
Protect-File 'C:\secrets.txt' -Algorithm DES -Suffix '.Encrypted' -RemoveSource
This example encrypts C:\secrets.txt with a randomly generated DES key. The encrypted file would have an extension of '.Encrypted' and the source (decrypted) file would be removed.

.EXAMPLE
Get-ChildItem 'C:\Files' -Recurse | Protect-File -Algorithm AES -Key $key -RemoveSource
This example encrypts all of the files under the C:\Files directory using the key stored in the variable $key. The encrypted files would have the default extension of '.AES' and the source (decrypted) files would be removed.

.NOTES
Author: Tyler Siegrist
Date: 9/22/2017
#>
[CmdletBinding(DefaultParameterSetName='SecureString')]
[OutputType([System.IO.FileInfo[]])]
Param(
    [Parameter(Mandatory=$true, Position=1, ValueFromPipeline=$true, ValueFromPipelineByPropertyName=$true)]
    [Alias('PSPath','LiteralPath')]
    [string[]]$FileName,
    [Parameter(Mandatory=$false, Position=2)]
    [ValidateSet('AES','DES','RC2','Rijndael','TripleDES')]
    [String]$Algorithm = 'AES',
    [Parameter(Mandatory=$false, Position=3, ParameterSetName='SecureString')]
    [System.Security.SecureString]$Key = (New-CryptographyKey -Algorithm $Algorithm),
    [Parameter(Mandatory=$true, Position=3, ParameterSetName='PlainText')]
    [String]$KeyAsPlainText,
    [Parameter(Mandatory=$false, Position=4)]
    [System.Security.Cryptography.CipherMode]$CipherMode,
    [Parameter(Mandatory=$false, Position=5)]
    [System.Security.Cryptography.PaddingMode]$PaddingMode,
    [Parameter(Mandatory=$false, Position=6)]
    [String]$Suffix = ".$Algorithm",
    [Parameter()]
    [Switch]$RemoveSource
)
    Begin
    {
        #Configure cryptography
        try
        {
            if($PSCmdlet.ParameterSetName -eq 'PlainText')
            {
                $Key = $KeyAsPlainText | ConvertTo-SecureString -AsPlainText -Force
            }

            #Decrypt cryptography Key from SecureString
            $BSTR = [System.Runtime.InteropServices.Marshal]::SecureStringToBSTR($Key)
            $EncryptionKey = [System.Convert]::FromBase64String([System.Runtime.InteropServices.Marshal]::PtrToStringAuto($BSTR))

            $Crypto = [System.Security.Cryptography.SymmetricAlgorithm]::Create($Algorithm)
            if($PSBoundParameters.ContainsKey('CipherMode')){
                $Crypto.Mode = $CipherMode
            }
            if($PSBoundParameters.ContainsKey('PaddingMode')){
                $Crypto.Padding = $PaddingMode
            }
            $Crypto.KeySize = $EncryptionKey.Length*8
            $Crypto.Key = $EncryptionKey
        }
        Catch
        {
            Write-Error $_ -ErrorAction Stop
        }
    }
    Process
    {
        $Files = Get-Item -LiteralPath $FileName
    
        ForEach($File in $Files)
        {
            $DestinationFile = $File.FullName + $Suffix

            Try
            {
                $FileStreamReader = New-Object System.IO.FileStream($File.FullName, [System.IO.FileMode]::Open)
                $FileStreamWriter = New-Object System.IO.FileStream($DestinationFile, [System.IO.FileMode]::Create)

                #Write IV (initialization-vector) length & IV to encrypted file
                $Crypto.GenerateIV()
                $FileStreamWriter.Write([System.BitConverter]::GetBytes($Crypto.IV.Length), 0, 4)
                $FileStreamWriter.Write($Crypto.IV, 0, $Crypto.IV.Length)

                #Perform encryption
                $Transform = $Crypto.CreateEncryptor()
                $CryptoStream = New-Object System.Security.Cryptography.CryptoStream($FileStreamWriter, $Transform, [System.Security.Cryptography.CryptoStreamMode]::Write)
                $FileStreamReader.CopyTo($CryptoStream)
    
                #Close open files
                $CryptoStream.FlushFinalBlock()
                $CryptoStream.Close()
                $FileStreamReader.Close()
                $FileStreamWriter.Close()

                #Delete unencrypted file
                if($RemoveSource){Remove-Item -LiteralPath $File.FullName}

                #Output ecrypted file
                $result = Get-Item $DestinationFile
                $result | Add-Member –MemberType NoteProperty –Name SourceFile –Value $File.FullName
                $result | Add-Member –MemberType NoteProperty –Name Algorithm –Value $Algorithm
                $result | Add-Member –MemberType NoteProperty –Name Key –Value $Key
                $result | Add-Member –MemberType NoteProperty –Name CipherMode –Value $Crypto.Mode
                $result | Add-Member –MemberType NoteProperty –Name PaddingMode –Value $Crypto.Padding
                $result
            }
            Catch
            {
                Write-Error $_
                If($FileStreamWriter)
                {
                    #Remove failed file
                    $FileStreamWriter.Close()
                    Remove-Item -LiteralPath $DestinationFile -Force
                }
                Continue
            }
            Finally
            {
                if($CryptoStream){$CryptoStream.Close()}
                if($FileStreamReader){$FileStreamReader.Close()}
                if($FileStreamWriter){$FileStreamWriter.Close()}
            }
        }
    }
}

Function Unprotect-File
{
<#
.SYNOPSIS 
Decrypts a file encrypted with Protect-File.

.DESCRIPTION
Decrypts a file using a provided cryptography key.

.PARAMETER FileName
File(s) to be decrypted.

.PARAMETER Key
Cryptography key as a SecureString be used for decryption.

.PARAMETER KeyAsPlainText
Cryptography key as a String to be used for decryption.

.PARAMETER CipherMode
Specifies the block cipher mode that was used for encryption.

.PARAMETER PaddingMode
Specifies the type of padding that was applied when the message data block was shorter than the full number of bytes needed for a cryptographic operation.

.PARAMETER Suffix
Suffix of the encrypted file to be removed.

.PARAMETER RemoveSource
Removes the source (encrypted) file after decrypting.

.OUTPUTS
System.IO.FileInfo. Unprotect-File will return FileInfo with the SourceFile as an added NoteProperty

.EXAMPLE
Unprotect-File 'C:\secrets.txt.AES' $key
This example decrypts C:\secrets.txt.AES using the key stored in the variable $key. The decrypted file would remove the default extension of '.AES' and the source (encrypted) file would not be removed.

.EXAMPLE
Unprotect-File 'C:\secrets.txt.Encrypted' -Algorithm DES -Key $key -Suffix '.Encrypted' -RemoveSource
This example decrypts C:\secrets.txt.Encrypted using DES and the key stored in the variable $key. The decrypted file would remove the extension of '.Encrypted' and the source (encrypted) file would be removed.

.EXAMPLE
Get-ChildItem 'C:\Files' -Recurse | Unprotect-File -Algorithm AES -Key $key -RemoveSource
This example decrypts all of the files under the C:\Files directory using the key stored in the variable $key. The decrypted files would remove the default extension of '.AES' and the source (encrypted) files would be removed.

.NOTES
Author: Tyler Siegrist
Date: 9/22/2017
#>
[CmdletBinding(DefaultParameterSetName='SecureString')]
[OutputType([System.IO.FileInfo[]])]
Param(
    [Parameter(Mandatory=$true, Position=1, ValueFromPipeline=$true, ValueFromPipelineByPropertyName=$true)]
    [Alias('PSPath','LiteralPath')]
    [string[]]$FileName,
    [Parameter(Mandatory=$false, Position=2, ValueFromPipelineByPropertyName=$true)]
    [ValidateSet('AES','DES','RC2','Rijndael','TripleDES')]
    [String]$Algorithm = 'AES',
    [Parameter(Mandatory=$true, Position=3, ValueFromPipelineByPropertyName=$true, ParameterSetName='SecureString')]
    [System.Security.SecureString]$Key,
    [Parameter(Mandatory=$true, Position=3, ParameterSetName='PlainText')]
    [String]$KeyAsPlainText,
    [Parameter(Mandatory=$false, Position=4, ValueFromPipelineByPropertyName=$true)]
    [System.Security.Cryptography.CipherMode]$CipherMode = 'CBC',
    [Parameter(Mandatory=$false, Position=5, ValueFromPipelineByPropertyName=$true)]
    [System.Security.Cryptography.PaddingMode]$PaddingMode = 'PKCS7',
    [Parameter(Mandatory=$false, Position=6)]
    [String]$Suffix, #Assigning default value in code due to it not processing ".$Algorithm" properly when Algorithm is ValueFromPipelineByPropertyName
    [Parameter()]
    [Switch]$RemoveSource
)
    Process
    {
        #Configure cryptography
        try
        {
            if($PSCmdlet.ParameterSetName -eq 'PlainText')
            {
                $Key = $KeyAsPlainText | ConvertTo-SecureString -AsPlainText -Force
            }

            #Decrypt cryptography Key from SecureString
            $BSTR = [System.Runtime.InteropServices.Marshal]::SecureStringToBSTR($Key)
            $EncryptionKey = [System.Convert]::FromBase64String([System.Runtime.InteropServices.Marshal]::PtrToStringAuto($BSTR))

            $Crypto = [System.Security.Cryptography.SymmetricAlgorithm]::Create($Algorithm)
            $Crypto.Mode = $CipherMode
            $Crypto.Padding = $PaddingMode
            $Crypto.KeySize = $EncryptionKey.Length*8
            $Crypto.Key = $EncryptionKey
        }
        Catch
        {
            Write-Error $_ -ErrorAction Stop
        }

        if(-not $PSBoundParameters.ContainsKey('Suffix'))
        {
            $Suffix = ".$Algorithm"
        }

        #Used to store successfully decrypted file names.
        $Files = Get-Item -LiteralPath $FileName

        ForEach($File in $Files)
        {
            #Verify file ends with supplied suffix
            If(-not $File.Name.EndsWith($Suffix))
            {
                Write-Error "$($File.FullName) does not have an extension of '$Suffix'."
                Continue
            }

            $DestinationFile = $File.FullName -replace "$Suffix$"

            Try
            {
                $FileStreamReader = New-Object System.IO.FileStream($File.FullName, [System.IO.FileMode]::Open)
                $FileStreamWriter = New-Object System.IO.FileStream($DestinationFile, [System.IO.FileMode]::Create)

                #Get IV from file
                [Byte[]]$LenIV = New-Object Byte[] 4
                $FileStreamReader.Seek(0, [System.IO.SeekOrigin]::Begin) | Out-Null
                $FileStreamReader.Read($LenIV,  0, 3) | Out-Null
                [Int]$LIV = [System.BitConverter]::ToInt32($LenIV,  0)
                [Byte[]]$IV = New-Object Byte[] $LIV
                $FileStreamReader.Seek(4, [System.IO.SeekOrigin]::Begin) | Out-Null
                $FileStreamReader.Read($IV, 0, $LIV) | Out-Null
                $Crypto.IV = $IV

                #Peform Decryption
                $Transform = $Crypto.CreateDecryptor()
                $CryptoStream = New-Object System.Security.Cryptography.CryptoStream($FileStreamWriter, $Transform, [System.Security.Cryptography.CryptoStreamMode]::Write)
                $FileStreamReader.CopyTo($CryptoStream)

                #Close open files
                $CryptoStream.FlushFinalBlock()
                $CryptoStream.Close()
                $FileStreamReader.Close()
                $FileStreamWriter.Close()

                #Delete encrypted file
                if($RemoveSource){Remove-Item $File.FullName}

                #Output decrypted file
                Get-Item $DestinationFile | Add-Member –MemberType NoteProperty –Name SourceFile –Value $File.FullName -PassThru
            }
            Catch
            {
                Write-Error $_
                If($FileStreamWriter)
                {
                    #Remove failed file
                    $FileStreamWriter.Close()
                    Remove-Item -LiteralPath $DestinationFile -Force
                }
                Continue
            }
            Finally
            {
                if($CryptoStream){$CryptoStream.Close()}
                if($FileStreamReader){$FileStreamReader.Close()}
                if($FileStreamWriter){$FileStreamWriter.Close()}
            }
        }
    }
}

Export-ModuleMember -Function New-CryptographyKey
Export-ModuleMember -Function Protect-File
Export-ModuleMember -Function Unprotect-File

*來源連結取自gjpio的答案。這個新答案包括實際程式碼，而不是依賴來源連結。我最初建議將此作為對 gjpio 答案的編輯，但我的編輯被拒絕，反饋是它應該是它自己的答案。

答案2

PS 庫中的這個腳本也許可以解決問題； https://gallery.technet.microsoft.com/scriptcenter/EncryptDecrypt-files-use-65e7ae5d

更新：畫廊已刪除。我在任何地方都找不到遷移的版本，但網路存檔有一個副本： https://web.archive.org/web/20200318045131/https://gallery.technet.microsoft.com/scriptcenter/EncryptDecrypt-files-use-65e7ae5d

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