(Excel) Get ECC Public Key in JWK Format (JSON Web Key)

Demonstrates how to get an ECC public key in JWK (JSON Web Key) format.

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

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' Note: This example requires Chilkat v9.5.0.66 or later.

' Load a PEM file into memory.
Dim sbPem As Chilkat.StringBuilder
Set sbPem = Chilkat.NewStringBuilder

success = sbPem.LoadFile("qa_data/pem/ecc_public.pem","utf-8")
If (success <> True) Then
    Debug.Print "Failed to load PEM file."
    Exit Sub
End If

' Load the PEM into a public key object.
Dim pubKey As Chilkat.PublicKey
Set pubKey = Chilkat.NewPublicKey
success = pubKey.LoadFromString(sbPem.GetAsString())
If (success <> True) Then
    Debug.Print pubKey.LastErrorText
    Exit Sub
End If

' Get the public key in JWK format:

jwk = pubKey.GetJwk()

' The GetJwk method will return the JWK in the most compact JSON format possible,
' as a single line with no extra whitespace.  To get a more human-readable JWK (for this example),
' load into a Chilkat JSON object and emit non-compact:

Dim json As Chilkat.JsonObject
Set json = Chilkat.NewJsonObject
Dim success As Boolean
success = json.Load(jwk)
json.EmitCompact = False
Debug.Print "ECC Public Key in JWK format:"
Debug.Print json.Emit()

' Sample output:
' { 
'   "kty": "EC",
'   "crv": "P-256",
'   "x": "oBUyo8CQAFPeYPvv78ylh5MwFZjTCLQeb042TjiMJxE",
'   "y": "vvQyxZkUjJQUPU_0bCy3Pj5qQdfu8jwEfqEeYGZ95CU"
' }
' 
' Additional information can be added like this:
success = json.AppendString("use","enc")
success = json.AppendString("kid","123ABC")

' Now examine the JSON:
Debug.Print json.Emit()

' { 
'   "kty": "EC",
'   "crv": "P-256",
'   "x": "oBUyo8CQAFPeYPvv78ylh5MwFZjTCLQeb042TjiMJxE",
'   "y": "vvQyxZkUjJQUPU_0bCy3Pj5qQdfu8jwEfqEeYGZ95CU",
'   "use": "enc",
'   "kid": "123ABC"
' }