(PowerShell) JWE using A256GCMKW

This example demonstrates creating a JCE with AES GCM key wrap.

Chilkat .NET Downloads Chilkat .NET Assemblies

Add-Type -Path "C:\chilkat\ChilkatDotNet47-9.5.0-x64\ChilkatDotNet47.dll"

# This requires the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

$plaintext = "My text to enrypt"

$jwe = New-Object Chilkat.Jwe

# First build the JWE Protected Header: 

#         {
#             "alg": "A256GCMKW",
#             "kid": "18ec08e1-bfa9-4d95-b205-2b4dd1d4321d",
#             "tag": "kfPduVQ3T3H6vnewt--ksw",
#             "iv": "KkYT0GX_2jHlfqN_",
#             "enc": "A128CBC-HS256"
#         }

$jweProtHdr = New-Object Chilkat.JsonObject
$jweProtHdr.AppendString("alg","A256GCMKW")
# kid is optional
$jweProtHdr.AppendString("kid","18ec08e1-bfa9-4d95-b205-2b4dd1d4321d")
# tag is optional
$jweProtHdr.AppendString("tag","kfPduVQ3T3H6vnewt--ksw")
$jweProtHdr.AppendString("enc","A256GCM")
# the iv should be 16 random chars.
$prng = New-Object Chilkat.Prng
$jweProtHdr.AppendString("iv",$prng.RandomString(16,$true,$true,$true))
$jwe.SetProtectedHeader($jweProtHdr)

$("JWE Protected Header: " + $jweProtHdr.Emit())
$("--")

# Given that we have 256-bit AES, our key should be 32 bytes.
# The ascii string here is 32 bytes, therefore the 2nd arg is "ascii" to use these
# ascii chars directly as the key.
$aesWrappingKey = "2baf4f730f5e4542b428593ef9cceb0e"
$jwe.SetWrappingKey(0,$aesWrappingKey,"ascii")

# Encrypt and return the JWE:
$strJwe = $jwe.Encrypt($plaintext,"utf-8")
if ($jwe.LastMethodSuccess -ne $true) {
    $($jwe.LastErrorText)
    exit
}

# Show the JWE we just created:
$($strJwe)

# Decrypt the JWE that was just produced.
# 1) Load the JWE.
# 2) Set the AES wrapping key.
# 3) Decrypt.
$jwe2 = New-Object Chilkat.Jwe
$success = $jwe2.LoadJwe($strJwe)
if ($success -ne $true) {
    $($jwe2.LastErrorText)
    exit
}

# Set the AES wrap key.  Important to use "ascii"
$jwe2.SetWrappingKey(0,$aesWrappingKey,"ascii")

# Decrypt.
$originalPlaintext = $jwe2.Decrypt(0,"utf-8")
if ($jwe2.LastMethodSuccess -ne $true) {
    $($jwe2.LastErrorText)
    exit
}

$("original text: ")
$($originalPlaintext)