PowerBuilder

JWE using "dir" Direct use of Shared Symmetric Key

See more JSON Web Encryption (JWE) Examples

Demonstrates how to create a JWE using the "dir" alg -- which is to directly use a shared symmetric key.

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

PowerBuilder

integer li_rc
integer li_Success
string ls_Plaintext
oleobject loo_Jwe
oleobject loo_JweProtHdr
integer li_RecipientIndex
string ls_StrJwe
oleobject loo_Jwe2
string ls_OriginalPlaintext

li_Success = 0

// 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.

ls_Plaintext = "Live long and prosper."

loo_Jwe = create oleobject
li_rc = loo_Jwe.ConnectToNewObject("Chilkat.Jwe")
if li_rc < 0 then
    destroy loo_Jwe
    MessageBox("Error","Connecting to COM object failed")
    return
end if

// First build the JWE Protected Header..
loo_JweProtHdr = create oleobject
li_rc = loo_JweProtHdr.ConnectToNewObject("Chilkat.JsonObject")

loo_JweProtHdr.AppendString("alg","dir")
loo_JweProtHdr.AppendString("enc","A128GCM")

// Don't forget to actually provide the protected header to the JWE object:
loo_Jwe.SetProtectedHeader(loo_JweProtHdr)

// The JWE is to use 128-bit AES GCM encryption as specified by the "enc" parameter.
// Given that the "alg" = "dir", we are to directly specify the AES GCM key.
// (It is assumed that the decrypting side also has knowledge of the direct key to be used..)

// Our key will be these 16 hex bytes: 000102030405060708090A0B0C0D0E0F

// The SetWrappingKey method is also used for "dir" direct keys.
// However, if there are multiple recipients, they must all share the same CEK (Content Encryption Key),
// which is specified by calling SetWrappingKey with an index of 0.

li_RecipientIndex = 0
loo_Jwe.SetWrappingKey(li_RecipientIndex,"000102030405060708090A0B0C0D0E0F","hex")

// Encrypt and return the JWE:
ls_StrJwe = loo_Jwe.Encrypt(ls_Plaintext,"utf-8")
if loo_Jwe.LastMethodSuccess <> 1 then
    Write-Debug loo_Jwe.LastErrorText
    destroy loo_Jwe
    destroy loo_JweProtHdr
    return
end if

// Show the JWE we just created:
Write-Debug ls_StrJwe

// Decrypt the JWE.
loo_Jwe2 = create oleobject
li_rc = loo_Jwe2.ConnectToNewObject("Chilkat.Jwe")

li_Success = loo_Jwe2.LoadJwe(ls_StrJwe)
if li_Success <> 1 then
    Write-Debug loo_Jwe2.LastErrorText
    destroy loo_Jwe
    destroy loo_JweProtHdr
    destroy loo_Jwe2
    return
end if

loo_Jwe2.SetWrappingKey(0,"000102030405060708090A0B0C0D0E0F","hex")

// Decrypt.
ls_OriginalPlaintext = loo_Jwe2.Decrypt(0,"utf-8")
if loo_Jwe2.LastMethodSuccess <> 1 then
    Write-Debug loo_Jwe2.LastErrorText
    destroy loo_Jwe
    destroy loo_JweProtHdr
    destroy loo_Jwe2
    return
end if

Write-Debug "original text: "
Write-Debug ls_OriginalPlaintext

// Sample output:
// eyJhbGciOiJkaXIiLCJlbmMiOiJBMTI4R0NNIn0..20HX5Huc7f1nQC4pBUtiCQ.axFZIxtZy5j0ifJQUzGXLKIpsBuxJA.eBrOC-NrsreN6JeGuOPk1g
// original text: 
// Live long and prosper.


destroy loo_Jwe
destroy loo_JweProtHdr
destroy loo_Jwe2