ConvertFrom-SecureString - PowerShell command help and examples

Converts a secure string into an encrypted standard string. (ConvertFrom-SecureString)

... Examples      
 NAME
 
    ConvertFrom-SecureString 

 SYNOPSIS
 
    Converts a secure string into an encrypted standard string. 

 SYNTAX
 
    ConvertFrom-SecureString [-Key <Byte[]>] [-SecureString] <SecureString> [<CommonParameters>] 

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

 DESCRIPTION
 
    The ConvertFrom-SecureString cmdlet converts a secure string (System.Security.SecureString) into an encrypted standard string (System.String). Unlike a secure string, an encrypted standard string can be saved in a file for later use. The encrypted standard string can be converted back to its secure string format by using the ConvertTo-SecureString cmdlet. If an encryption key is specified by using the Key or SecureKey parameters, the Rijndael encryption algorithm is used. The specified key must have a length of 128, 192, or 256 bits because those are the key lengths supported by the Rijndael encryption algorithm. If no key is specified, the Windows Data Protection API (DPAPI) is used to encrypt the standard string representation. 

 PARAMETERS
 
    -Key <Byte[]> 
        Specifies the encryption key as a byte array. 

        Required?                    false 
        Position?                    named 
        Default value 
        Accept pipeline input?       false 
        Accept wildcard characters?  false 

    -SecureKey <SecureString> 
        Specifies the encryption key as a secure string. The secure string value is converted to a byte array before being used as the key. 

        Required?                    false 
        Position?                    2 
        Default value 
        Accept pipeline input?       false 
        Accept wildcard characters?  false 

    -SecureString <SecureString> 
        Specifies the secure string to convert to an encrypted standard string. 

        Required?                    true 
        Position?                    1 
        Default value 
        Accept pipeline input?       true (ByValue) 
        Accept wildcard characters?  false 

    <CommonParameters> 
        This cmdlet supports the common parameters: Verbose, Debug, 
        ErrorAction, ErrorVariable, WarningAction, WarningVariable, 
        OutBuffer and OutVariable. For more information, type, 
        "get-help about_commonparameters". 

 INPUTS
 
    System.Security.SecureString 
        You can pipe a SecureString object to ConvertFrom-SecureString. 

 OUTPUTS
 
    System.String 
        ConvertFrom-SecureString returns a standard string object. 

 NOTES
 

        To create a secure string from characters that are typed at the command prompt, use the AsSecureString parameter of the Read-Host cmdlet. 

        When you use the Key or SecureKey parameters to specify a key, the key length must be correct. For example, a key of 128 bits can be specified as a byte array of 16 digits. Similarly, 192-bit and 256-bit keys correspond to byte arrays of 24 and 32 digits, respectively. 

 Examples
    
EXAMPLE 1
 

    C:\PS>$securestring = read-host -assecurestring 

     Description
 
    ----------- 
    This command creates a secure string from characters that you type at the command prompt. After entering the command, type the string you want to store as a secure string. An asterisk (*) will be displayed to represent each character that you type. 

    
EXAMPLE 2
 

    C:\PS>$standardstring = convertfrom-securestring  $securestring 

     Description
 
    ----------- 
    This command converts the secure string in the $securestring variable to an encrypted standard string. The resulting encrypted standard string is stored in the $standardstring variable. 

    
EXAMPLE 3
 

    C:\PS>$key = (3,4,2,3,56,34,254,222,1,1,2,23,42,54,33,233,1,34,2,7,6,5,35,43) 

    C:\PS> $standardstring = convertfrom-securestring  $securestring -key $key 

     Description
 
    ----------- 
    These commands use the Rijndael algorithm to convert the secure string stored in the $securestring variable to an encrypted standard string with a 192-bit key. The resulting encrypted standard string is stored in the $standardstring variable. 

    The first command stores a key in the $key variable. The key is an array of 24 digits, all of which are less than 256. 

    Because each digit represents a byte (8 bits), the key has 24 digits for a total of 192 bits (8 x 24). This is a valid key length for the Rijndael algorithm. Each individual value is less than 256, which is the maximum value that can be stored in an unsigned byte. 

    The second command uses the key in the $key variable to convert the secure string to an encrypted standard string. 

RELATED LINKS 
    Online version: http://go.microsoft.com/fwlink/?LinkID=113287 
    ConvertTo-SecureString 
    Read-Host 

C:\Windows>powershell get-help ConvertTo-SecureString -full 

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