Payment Protocol: X509-validated payment requests

Add support for a Payment Protocol to Bitcoin-Qt.

Payment messages are protocol-buffer encoded and communicated over
http(s), so this adds a dependency on the Google protocol buffer
library, and requires Qt with OpenSSL support.

1 files changed, 46 insertions, 0 deletions

diff --git a/src/qt/paymentrequest.proto b/src/qt/paymentrequest.proto
new file mode 100644
index 0000000000..b2281c4c7b
--- /dev/null
+++ b/src/qt/paymentrequest.proto
@@ -0,0 +1,46 @@
+//
+// Simple Bitcoin Payment Protocol messages
+//
+// Use fields 100+ for extensions;
+// to avoid conflicts, register extensions at:
+// https://en.bitcoin.it/wiki/Payment_Request
+//
+
+package payments;
+option java_package = "org.bitcoin.protocols.payments";
+option java_outer_classname = "Protos";
+
+// Generalized form of "send payment to this/these bitcoin addresses"
+message Output {
+	optional uint64 amount = 1 [default = 0]; // amount is integer-number-of-satoshis
+	required bytes script = 2; // usually one of the standard Script forms
+}
+message PaymentDetails {
+        optional string network = 1 [default = "main"]; // "main" or "test"
+        repeated Output outputs = 2;        // Where payment should be sent
+        required uint64 time = 3;           // Timestamp; when payment request created
+        optional uint64 expires = 4;        // Timestamp; when this request should be considered invalid
+        optional string memo = 5;           // Human-readable description of request for the customer
+        optional string payment_url = 6;    // URL to send Payment and get PaymentACK
+        optional bytes merchant_data = 7;   // Arbitrary data to include in the Payment message
+}
+message PaymentRequest {
+        optional uint32 payment_details_version = 1 [default = 1];
+        optional string pki_type = 2 [default = "none"];  // none / x509+sha256 / x509+sha1
+        optional bytes pki_data = 3;                      // depends on pki_type
+        required bytes serialized_payment_details = 4;    // PaymentDetails
+        optional bytes signature = 5;                     // pki-dependent signature
+}
+message X509Certificates {
+        repeated bytes certificate = 1;    // DER-encoded X.509 certificate chain
+}
+message Payment {
+        optional bytes merchant_data = 1;  // From PaymentDetails.merchant_data
+        repeated bytes transactions = 2;   // Signed transactions that satisfy PaymentDetails.outputs
+        repeated Output refund_to = 3;     // Where to send refunds, if a refund is necessary
+        optional string memo = 4;          // Human-readable message for the merchant
+}
+message PaymentACK {
+        required Payment payment = 1;      // Payment message that triggered this ACK
+        optional string memo = 2;          // human-readable message for customer
+}