Visual Basic 6.0

Load ECC Public Key from JWK Format (JSON Web Key)

See more ECC Examples

Demonstrates how to load an ECC public key from JWK (JSON Web Key) format.

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

Visual Basic 6.0

Dim success As Long
success = 0

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

' First build a JWK sample to load..
Dim json As New ChilkatJsonObject
success = json.UpdateString("kty","EC")
success = json.UpdateString("crv","P-256")
success = json.UpdateString("x","oBUyo8CQAFPeYPvv78ylh5MwFZjTCLQeb042TjiMJxE")
success = json.UpdateString("y","vvQyxZkUjJQUPU_0bCy3Pj5qQdfu8jwEfqEeYGZ95CU")

' The JSON contains the following:
' { 
'   "kty": "EC",
'   "crv": "P-256",
'   "x": "oBUyo8CQAFPeYPvv78ylh5MwFZjTCLQeb042TjiMJxE",
'   "y": "vvQyxZkUjJQUPU_0bCy3Pj5qQdfu8jwEfqEeYGZ95CU",
' }

' Note: The JSON can contain other members, such as "use", "kid", or anything else.  These will be ignored.
json.EmitCompact = 0

' Show the JWK string to be loaded:
Dim jwkStr As String
jwkStr = json.Emit()

Dim pubKey As New PublicKey
' The LoadFromString method will automatically detect the format.
success = pubKey.LoadFromString(jwkStr)
If (success <> 1) Then
    Debug.Print pubKey.LastErrorText
    Exit Sub
End If

' OK.. the JWK is loaded.  It can be used in whatever way desired...

' The key can be retrieved in any other format, such as XML or PEM..
Debug.Print pubKey.GetXml()

' XML output:
' <ECCPublicKey curve="secp256r1" 
'    x="A01532A3C0900053DE60FBEFEFCCA58793301598D308B41E6F4E364E388C2711" 
'    y="BEF432C599148C94143D4FF46C2CB73E3E6A41D7EEF23C047EA11E60667DE425">
'    MIIBSzCCAQMGByqGSM49AgEwgfcCAQEwLAYHKoZIzj0BAQIhAP////8AAAABAAAAAAAAAAAAAAAA////////////////MFsEIP////8AAAABAAAAAAAAAAAAAAAA///////////////8BCBaxjXYqjqT57PrvVV2mIa8ZR0GsMxTsPY7zjw+J9JgSwMVAMSdNgiG5wSTamZ44ROdJreBn36QBEEEaxfR8uEsQkf4vOblY6RA8ncDfYEt6zOg9KE5RdiYwpZP40Li/hp/m47n60p8D54WK84zV2sxXs7LtkBoN79R9QIhAP////8AAAAA//////////+85vqtpxeehPO5ysL8YyVRAgEBA0IABKAVMqPAkABT3mD77+/MpYeTMBWY0wi0Hm9ONk44jCcRvvQyxZkUjJQUPU/0bCy3Pj5qQdfu8jwEfqEeYGZ95CU=
' </ECCPublicKey>

' Choose PCKS1 or PCKS8 PEM format..
Dim bPreferPkcs1 As Long
bPreferPkcs1 = 0
Debug.Print pubKey.GetPem(bPreferPkcs1)

' PEM output
' -----BEGIN PUBLIC KEY-----
' MIIBSzCCAQMGByqGSM49AgEwgfcCAQEwLAYHKoZIzj0BAQIhAP////8AAAABAAAA
' AAAAAAAAAAAA////////////////MFsEIP////8AAAABAAAAAAAAAAAAAAAA////
' ///////////8BCBaxjXYqjqT57PrvVV2mIa8ZR0GsMxTsPY7zjw+J9JgSwMVAMSd
' NgiG5wSTamZ44ROdJreBn36QBEEEaxfR8uEsQkf4vOblY6RA8ncDfYEt6zOg9KE5
' RdiYwpZP40Li/hp/m47n60p8D54WK84zV2sxXs7LtkBoN79R9QIhAP////8AAAAA
' //////////+85vqtpxeehPO5ysL8YyVRAgEBA0IABKAVMqPAkABT3mD77+/MpYeT
' MBWY0wi0Hm9ONk44jCcRvvQyxZkUjJQUPU/0bCy3Pj5qQdfu8jwEfqEeYGZ95CU=
' -----END PUBLIC KEY-----