Lianja

Set JWE Additional Authenticated Data

See more JSON Web Encryption (JWE) Examples

Demonstrates Jwe.SetAad, which sets external Additional Authenticated Data (AAD) for a JWE being encrypted, encoding the supplied text with the given charset.

Background. AAD is integrity-protected but not encrypted, binding external context to the ciphertext. The same AAD must be supplied again when decrypting.

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llSuccess = .F.

loJwe = createobject("CkJwe")

//  Protected header: AES key-wrap with AES-256-GCM content encryption.
loHeader = createobject("CkJsonObject")
loHeader.UpdateString("alg","A256KW")
loHeader.UpdateString("enc","A256GCM")
llSuccess = loJwe.SetProtectedHeader(loHeader)
if (llSuccess = .F.) then
    ? loJwe.LastErrorText
    release loJwe
    release loHeader
    return
endif

//  The 256-bit key-wrapping key (base64) for recipient index 0.  In production, obtain the key from a
//  secure source rather than hard-coding it.
lcBase64Key = "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXowMTIzNDU="
llSuccess = loJwe.SetWrappingKey(0,lcBase64Key,"base64")
if (llSuccess = .F.) then
    ? loJwe.LastErrorText
    release loJwe
    release loHeader
    return
endif

//  Set external Additional Authenticated Data (AAD).  The AAD is integrity-protected but not
//  encrypted, and must be supplied again when decrypting.
llSuccess = loJwe.SetAad("context-info-v1","utf-8")
if (llSuccess = .F.) then
    ? loJwe.LastErrorText
    release loJwe
    release loHeader
    return
endif

loSbContent = createobject("CkStringBuilder")
loSbContent.Append("This is the secret content.")
loSbJwe = createobject("CkStringBuilder")
llSuccess = loJwe.EncryptSb(loSbContent,"utf-8",loSbJwe)
if (llSuccess = .F.) then
    ? loJwe.LastErrorText
    release loJwe
    release loHeader
    release loSbContent
    release loSbJwe
    return
endif

? loSbJwe.GetAsString()


release loJwe
release loHeader
release loSbContent
release loSbJwe