(PowerShell) JWE using RSAES-PKCS1-v1_5 and AES_128_CBC_HMAC_SHA_256

This example duplicates the example A.2 in RFC 7516 for JSON Web Encryption (JWE).

Note: This example requires Chilkat v9.5.0.66 or greater.

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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.

# Note: This example requires Chilkat v9.5.0.66 or greater.

$plaintext = "Live long and prosper."

# First build the JWE Protected Header.
# We want to build this: {"alg":"RSA1_5","enc":"A128CBC-HS256"}
$jweProtHdr = New-Object Chilkat.JsonObject
$jweProtHdr.AppendString("alg","RSA1_5")
$jweProtHdr.AppendString("enc","A128CBC-HS256")
$("JWE Protected Header: " + $jweProtHdr.Emit())
$("--")

# The specific RSA key used in the A.2 example is the following JWK:
$sbJwk = New-Object Chilkat.StringBuilder
$sbJwk.Append("{`"kty`":`"RSA`",")
$sbJwk.Append("`"n`":`"sXchDaQebHnPiGvyDOAT4saGEUetSyo9MKLOoWFsueri23bOdgWp4Dy1Wl")
$sbJwk.Append("UzewbgBHod5pcM9H95GQRV3JDXboIRROSBigeC5yjU1hGzHHyXss8UDpre")
$sbJwk.Append("cbAYxknTcQkhslANGRUZmdTOQ5qTRsLAt6BTYuyvVRdhS8exSZEy_c4gs_")
$sbJwk.Append("7svlJJQ4H9_NxsiIoLwAEk7-Q3UXERGYw_75IDrGA84-lA_-Ct4eTlXHBI")
$sbJwk.Append("Y2EaV7t7LjJaynVJCpkv4LKjTTAumiGUIuQhrNhZLuF_RJLqHpM2kgWFLU")
$sbJwk.Append("7-VTdL1VbC2tejvcI2BlMkEpk1BzBZI0KQB0GaDWFLN-aEAw3vRw`",")
$sbJwk.Append("`"e`":`"AQAB`",")
$sbJwk.Append("`"d`":`"VFCWOqXr8nvZNyaaJLXdnNPXZKRaWCjkU5Q2egQQpTBMwhprMzWzpR8Sxq")
$sbJwk.Append("1OPThh_J6MUD8Z35wky9b8eEO0pwNS8xlh1lOFRRBoNqDIKVOku0aZb-ry")
$sbJwk.Append("nq8cxjDTLZQ6Fz7jSjR1Klop-YKaUHc9GsEofQqYruPhzSA-QgajZGPbE_")
$sbJwk.Append("0ZaVDJHfyd7UUBUKunFMScbflYAAOYJqVIVwaYR5zWEEceUjNnTNo_CVSj")
$sbJwk.Append("-VvXLO5VZfCUAVLgW4dpf1SrtZjSt34YLsRarSb127reG_DUwg9Ch-Kyvj")
$sbJwk.Append("T1SkHgUWRVGcyly7uvVGRSDwsXypdrNinPA4jlhoNdizK2zF2CWQ`",")
$sbJwk.Append("`"p`":`"9gY2w6I6S6L0juEKsbeDAwpd9WMfgqFoeA9vEyEUuk4kLwBKcoe1x4HG68")
$sbJwk.Append("ik918hdDSE9vDQSccA3xXHOAFOPJ8R9EeIAbTi1VwBYnbTp87X-xcPWlEP")
$sbJwk.Append("krdoUKW60tgs1aNd_Nnc9LEVVPMS390zbFxt8TN_biaBgelNgbC95sM`",")
$sbJwk.Append("`"q`":`"uKlCKvKv_ZJMVcdIs5vVSU_6cPtYI1ljWytExV_skstvRSNi9r66jdd9-y")
$sbJwk.Append("BhVfuG4shsp2j7rGnIio901RBeHo6TPKWVVykPu1iYhQXw1jIABfw-MVsN")
$sbJwk.Append("-3bQ76WLdt2SDxsHs7q7zPyUyHXmps7ycZ5c72wGkUwNOjYelmkiNS0`",")
$sbJwk.Append("`"dp`":`"w0kZbV63cVRvVX6yk3C8cMxo2qCM4Y8nsq1lmMSYhG4EcL6FWbX5h9yuv")
$sbJwk.Append("ngs4iLEFk6eALoUS4vIWEwcL4txw9LsWH_zKI-hwoReoP77cOdSL4AVcra")
$sbJwk.Append("Hawlkpyd2TWjE5evgbhWtOxnZee3cXJBkAi64Ik6jZxbvk-RR3pEhnCs`",")
$sbJwk.Append("`"dq`":`"o_8V14SezckO6CNLKs_btPdFiO9_kC1DsuUTd2LAfIIVeMZ7jn1Gus_Ff")
$sbJwk.Append("7B7IVx3p5KuBGOVF8L-qifLb6nQnLysgHDh132NDioZkhH7mI7hPG-PYE_")
$sbJwk.Append("odApKdnqECHWw0J-F0JWnUd6D2B_1TvF9mXA2Qx-iGYn8OVV1Bsmp6qU`",")
$sbJwk.Append("`"qi`":`"eNho5yRBEBxhGBtQRww9QirZsB66TrfFReG_CcteI1aCneT0ELGhYlRlC")
$sbJwk.Append("tUkTRclIfuEPmNsNDPbLoLqqCVznFbvdB7x-Tl-m0l_eFTj2KiqwGqE9PZ")
$sbJwk.Append("B9nNTwMVvH3VRRSLWACvPnSiwP8N5Usy-WRXS-V7TbpxIhvepTfE0NNo`"")
$sbJwk.Append("}")

# Load this JWK into a Chilkat private key object.
$rsaPrivKey = New-Object Chilkat.PrivateKey
$success = $rsaPrivKey.LoadJwk($sbJwk.GetAsString())
if ($success -ne $true) {
    $($rsaPrivKey.LastErrorText)
    exit
}

# The public key is used to encrypt (i.e. create the JWE), 
# and the private key is used to decrypt.
# The RSA public key is simply a subset of the private key.  The RSA public key
# is composed of the "n" and "e" members shown above.  These are also known as the
# modulus and exponent.
# We can simply get the public key object from the private key object
$rsaPubKey = $rsaPrivKey.GetPublicKey()

# Create the JWE...
$jwe = New-Object Chilkat.Jwe
$jwe.SetProtectedHeader($jweProtHdr)
$jwe.SetPublicKey(0,$rsaPubKey)

$strJwe = $jwe.Encrypt($plaintext,"utf-8")
if ($jwe.LastMethodSuccess -ne $true) {
    $($jwe.LastErrorText)
    exit
}

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

# Note: The RSA PKCS1_V1_5 padding uses random value, and the results
# will be different each time.  However, each result should be successfully
# decrypting if using the correct RSA private key.

# Let's decrypt the JWE that was just produced.
# Do the following to decrypt a JWE:
# 1) Load the JWE.
# 2) Set the private key for decryption.
# 3) Decrypt.
$jwe2 = New-Object Chilkat.Jwe
$success = $jwe2.LoadJwe($strJwe)
if ($success -ne $true) {
    $($jwe2.LastErrorText)
    exit
}

# Provide the RSA private key for decryption.
# (The JWE was encrypted for a single recipient at index 0.)
$jwe2.SetPrivateKey(0,$rsaPrivKey)

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

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

# ---------------------------------------------------------------------------------
# It should also be possible to decrypt the JWE as shown in RFC 7516, Appendix A.2.7
# because it was produced using the same RSA key.

$sbJwe = New-Object Chilkat.StringBuilder
$sbJwe.Append("eyJhbGciOiJSU0ExXzUiLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0.")
$sbJwe.Append("UGhIOguC7IuEvf_NPVaXsGMoLOmwvc1GyqlIKOK1nN94nHPoltGRhWhw7Zx0-kFm")
$sbJwe.Append("1NJn8LE9XShH59_i8J0PH5ZZyNfGy2xGdULU7sHNF6Gp2vPLgNZ__deLKxGHZ7Pc")
$sbJwe.Append("HALUzoOegEI-8E66jX2E4zyJKx-YxzZIItRzC5hlRirb6Y5Cl_p-ko3YvkkysZIF")
$sbJwe.Append("NPccxRU7qve1WYPxqbb2Yw8kZqa2rMWI5ng8OtvzlV7elprCbuPhcCdZ6XDP0_F8")
$sbJwe.Append("rkXds2vE4X-ncOIM8hAYHHi29NX0mcKiRaD0-D-ljQTP-cFPgwCp6X-nZZd9OHBv")
$sbJwe.Append("-B3oWh2TbqmScqXMR4gp_A.")
$sbJwe.Append("AxY8DCtDaGlsbGljb3RoZQ.")
$sbJwe.Append("KDlTtXchhZTGufMYmOYGS4HffxPSUrfmqCHXaI9wOGY.")
$sbJwe.Append("9hH0vgRfYgPnAHOd8stkvw")

$success = $jwe2.LoadJweSb($sbJwe)
if ($success -ne $true) {
    $($jwe2.LastErrorText)
    exit
}

# Provide the RSA private key for decryption.
$jwe2.SetPrivateKey(0,$rsaPrivKey)

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

$($originalPlaintext)