Convert a secure string to plain text

I'm working in PowerShell and I have code that successfully converts a user entered password into plain text:

$SecurePassword = Read-Host -AsSecureString  "Enter password" | convertfrom-securestring | out-file C:\Users\tmarsh\Documents\securePassword.txt

I've been tried several ways to convert it back, but none of them seem to work properly. Most recently, I've tried with the following:

$PlainPassword = Get-Content C:\Users\tmarsh\Documents\securePassword.txt


#convert the SecureString object to plain text using PtrToString and SecureStringToBSTR
$BSTR = [System.Runtime.InteropServices.Marshal]::SecureStringToBSTR($PlainPassword)
$PlainPassword = [System.Runtime.InteropServices.Marshal]::PtrToStringAuto($BSTR)
[Runtime.InteropServices.Marshal]::ZeroFreeBSTR($BSTR) #this is an important step to keep things secure

This gives me an error as well.

Cannot convert argument "s", with value: "01000000d08c9ddf0115d1118c7a00c04fc297eb0100000026a5b6067d53fd43801a9ef3f8ef9e43000000000200000000000366000
0c0000000100000008118fdea02bfb57d0dda41f9748a05f10000000004800000a000000010000000c50f5093f3b87fbf9ee57cbd17267e0a10000000833d1d712cef01497872a3457bc8
bc271400000038c731cb8c47219399e4265515e9569438d8e8ed", for "SecureStringToBSTR" to type "System.Security.SecureString": "Cannot convert the "01000000
d08c9ddf0115d1118c7a00c04fc297eb0100000026a5b6067d53fd43801a9ef3f8ef9e430000000002000000000003660000c0000000100000008118fdea02bfb57d0dda41f9748a05f10
000000004800000a000000010000000c50f5093f3b87fbf9ee57cbd17267e0a10000000833d1d712cef01497872a3457bc8bc271400000038c731cb8c47219399e4265515e9569438d8e8
ed" value of type "System.String" to type "System.Security.SecureString"."
At C:\Users\tmarsh\Documents\Scripts\Local Admin Script\PlainTextConverter1.ps1:14 char:1
+ $BSTR = [System.Runtime.InteropServices.Marshal]::SecureStringToBSTR($PlainPassw ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo          : NotSpecified: (:) [], MethodException
+ FullyQualifiedErrorId : MethodArgumentConversionInvalidCastArgument


Cannot find an overload for "PtrToStringAuto" and the argument count: "1".
At C:\Users\tmarsh\Documents\Scripts\Local Admin Script\PlainTextConverter1.ps1:15 char:1
+ $PlainPassword = [System.Runtime.InteropServices.Marshal]::PtrToStringAuto($BSTR ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo          : NotSpecified: (:) [], MethodException
+ FullyQualifiedErrorId : MethodCountCouldNotFindBest


Cannot convert argument "s", with value: "", for "ZeroFreeBSTR" to type "System.IntPtr": "Cannot convert null to type "System.IntPtr"."
At C:\Users\tmarsh\Documents\Scripts\Local Admin Script\PlainTextConverter1.ps1:16 char:1
+ [Runtime.InteropServices.Marshal]::ZeroFreeBSTR($BSTR) #this is an important ste ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo          : NotSpecified: (:) [], MethodException
+ FullyQualifiedErrorId : MethodArgumentConversionInvalidCastArgument


Password is:  01000000d08c9ddf0115d1118c7a00c04fc297eb0100000026a5b6067d53fd43801a9ef3f8ef9e430000000002000000000003660000c0000000100000008118fdea02bfb57d0dda41f97
48a05f10000000004800000a000000010000000c50f5093f3b87fbf9ee57cbd17267e0a10000000833d1d712cef01497872a3457bc8bc271400000038c731cb8c47219399e4265515e9569
438d8e8ed

Does anyone know of a way that will work for this?

173882

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最佳答案

接近了，但是传递给 SecureStringToBSTR的参数必须是 SecureString。您似乎正在传递 ConvertFrom-SecureString的结果，它是一个加密的标准字符串。因此，在传递给 SecureStringToBSTR之前，对此调用 ConvertTo-SecureString。

$SecurePassword = ConvertTo-SecureString $PlainPassword -AsPlainText -Force
$BSTR = [System.Runtime.InteropServices.Marshal]::SecureStringToBSTR($SecurePassword)
$UnsecurePassword = [System.Runtime.InteropServices.Marshal]::PtrToStringAuto($BSTR)

小开

可以使用 PSCredential. GetNetworkCredential () :

$UnsecurePassword = (New-Object PSCredential 0, $SecurePassword).GetNetworkCredential().Password

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在 PowerShell 中将其转换回来的最简单方法

[System.Net.NetworkCredential]::new("", $SecurePassword).Password

小开

在 PS7中，你可以使用 ConvertFrom-SecureString和 -AsPlainText:

#Requires -Version 7.0


$UnsecurePassword = ConvertFrom-SecureString -SecureString $SecurePassword -AsPlainText

Https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.security/convertfrom-securestring?view=powershell-7#parameters

ConvertFrom-SecureString
[-SecureString] <SecureString>
[-AsPlainText]
[<CommonParameters>]