Certificate Hash

Question

dsmithar15 OP

Created Sep ’15

Replies 4

Boosts 0

Views 4k

Participants 4

Having issues calculating the hash for validation.

In the documentation for decrypting an ApplePay Payment Token:

Use the value of the

publicKeyHash

key to determine which merchant public key was used by Apple, and then retrieve the corresponding merchant public key certificate and private key.

I can't seem to get the hash to generate properly. Is the public key in the X509 returned by apple in the initial certificate exchange the correct one to use?

I'm doing this decryption at the gateway level, my code is in C# using BouncyCastle. Any help is appreciated.

Boost

Answer 1

muxa OP

Feb ’16

I am facing the same problem. When i generate hash of public key bytes of the certificate used for merchant id i get a different value to the one sent to me vi

publicKeyHash

.

Have you managed to get this solved?

0

Answer 2

muxa OP

Feb ’16

Initially I was doing this (in C#):

var cert = X509Certificate.CreateFromCertFile(fileName);
var publicKey = cert.GetPublicKey();
var hash = SHA256.Create().ComputeHash(publicKey);

This produced a different result to what i got form the paymentDataToken.

The working solution that I have found is to use BouncyCastle:

Org.BouncyCastle.X509.X509Certificate cert = LoadCert(fileName);
var publicKeyInfo = cert.CertificateStructure.SubjectPublicKeyInfo;
var hash = sha256.ComputeHash(publicKeyInfo.ToAsn1Object().GetEncoded());

This hash matches the publicKeyHash from paymentDataToken

0

Answer 3

mybootcamp OP

Apr ’17

Muxa,

Have you been able to decrypt the payment token with Apple Pay JS?

0

Answer 4

Vadzimka OP

Oct ’17

Take a look here: https://github.com/sidimansourjs/applepay-token

0