View PIN

This operation retrieves card PIN encrypted with temporary PIN encryption key (tzpk) and tzpk encrypted with the provided RSA public key.

Note: The card-holder device must be generating the RSA key, and must not allow any other system to access the private RSA key. The RSA key should be a temporary one-time use key.

Example flow

Step 1, executed on the CARD-HOLDER DEVICE, generating an RSA key pair

// generate RSA key pair var kpg = KeyPairGenerator.getInstance(“RSA”); kpg.initialize(2048); var keyPair = kpg.generateKeyPair(); var publicKey = Base64.getEncoder().encodeToString(keyPair.getPublic().getEncoded());

Step 2, executed on the CLIENT BACK-END, requesting the encrypted PIN from the API

// controlId received from pincontrol API var controlId = “83fa5f55-3dd7-453a-8233-4242a6bad179”;

// public RSA key, generated by the card-holder device in Step 1 var publicKey = // fetched from the device

// make request var pinResponse = pinApiClient.post() .uri(“/pin/v3/view?auditUser=”, “test”) .bodyValue(Map.of( “controlId”, controlId, “publicKey”, publicKey )) .retrieve() .bodyToMono(ViewPinResponse.class) .block();

Step 3, executed on the CARD-HOLDER DEVICE, decrypting the PIN

// response from the API call done in Step 2, given by the backend var pinResponse = // given by the backend

// decrypt received tzpk with private key var rsa = Cipher.getInstance(“RSA/ECB/OAEPPadding”); rsa.init(Cipher.DECRYPT_MODE, keyPair.getPrivate(), new OAEPParameterSpec(“SHA-256”, “MGF1”, MGF1ParameterSpec.SHA256, PSource.PSpecified.DEFAULT)); var decryptedTzpk = rsa.doFinal(Base64.getDecoder().decode(pinResponse.getTzpk())); // convert double-length key to triple-length - used if the library support only triple-length 3DES var tzpk = new byte[24]; System.arraycopy(decryptedTzpk, 0, tzpk, 0, 16); System.arraycopy(decryptedTzpk, 0, tzpk, 16, 8); // decrypt pinBlock with tzpk var des = Cipher.getInstance(“DESede/ECB/NoPadding”); des.init(Cipher.DECRYPT_MODE, new SecretKeySpec(tzpk, “DESede”)); var decryptedPinBlock = Hex.toHexString(des.doFinal(Base64.getDecoder().decode(pinResponse.getPinBlock())));