(Excel) Get ECC Public Key from ECC Private Key

Demonstrates how to get an ECC public key from an ECC private key.

Download Excel Class Modules Chilkat Excel Class Modules

' We have an ECC private key...
' The contents of the private key PEM file look like this:

' 	-----BEGIN PRIVATE KEY-----
' 	MIGHAgEAMBMGByqGSM49AgEGCCqGSM49AwEHBG0wawIBAQQg3J8q/24D1sEKGdP9
' 	72MGYElLGpw/a56Y3t6pfON3uhShRANCAATlSmoizyhAwoYZAOuFBATl07/1RR54
' 	a1Dzfm16grxJe666AGKR+bSs24hk7TEpaeCTvT8YOOM3l+xKFg7zq6Q9
' 	-----END PRIVATE KEY-----

Dim privKey As Chilkat.PrivateKey
Set privKey = Chilkat.NewPrivateKey

success = privKey.LoadPemFile("qa_data/ecc/secp256r1-key-pkcs8.pem")
If (success <> True) Then
    Debug.Print privKey.LastErrorText
    Exit Sub
End If

' Get the public key.

Set pubKey = privKey.GetPublicKey()
If (privKey.LastMethodSuccess <> True) Then
    Debug.Print privKey.LastErrorText
    Exit Sub
End If

' Save the public key to a PEM file.
success = pubKey.SavePemFile(False,"qa_data/ecc/secp256r1-pubkey.pem")
If (success <> True) Then
    Debug.Print pubKey.LastErrorText

    Exit Sub
End If

' The contents of the ECC public key PEM file look like this:

' 	-----BEGIN PUBLIC KEY-----
' 	MIIBSzCCAQMGByqGSM49AgEwgfcCAQEwLAYHKoZIzj0BAQIhAP////8AAAABAAAA
' 	AAAAAAAAAAAA////////////////MFsEIP////8AAAABAAAAAAAAAAAAAAAA////
' 	///////////8BCBaxjXYqjqT57PrvVV2mIa8ZR0GsMxTsPY7zjw+J9JgSwMVAMSd
' 	NgiG5wSTamZ44ROdJreBn36QBEEEaxfR8uEsQkf4vOblY6RA8ncDfYEt6zOg9KE5
' 	RdiYwpZP40Li/hp/m47n60p8D54WK84zV2sxXs7LtkBoN79R9QIhAP////8AAAAA
' 	//////////+85vqtpxeehPO5ysL8YyVRAgEBA0IABOVKaiLPKEDChhkA64UEBOXT
' 	v/VFHnhrUPN+bXqCvEl7rroAYpH5tKzbiGTtMSlp4JO9Pxg44zeX7EoWDvOrpD0=
' 	-----END PUBLIC KEY-----

Debug.Print "Success."