Add silentpayments_test_outputs

Author: jlest01

examples/silentpayments.c

@@ -111,7 +111,11 @@ const unsigned char* label_lookup(
 }
 
 int main(void) {
-    enum { N_TX_INPUTS = 2, N_TX_OUTPUTS = 3 };
+    enum { N_TX_INPUTS = 2, N_TX_OUTPUTS = 3, N_OUT_PUBKEYS = 198 };
+
+    int n_out_pubkeys = N_OUT_PUBKEYS;
+    unsigned char out_pubkeys[N_OUT_PUBKEYS];
+
     unsigned char randomize[32];
     unsigned char xonly_print[32];
     secp256k1_xonly_pubkey tx_inputs[N_TX_INPUTS];
@@ -219,8 +223,17 @@ int main(void) {
             generated_output_ptrs[i] = &generated_outputs[i];
         }
 
-        ret = secp256k1_silentpayments_test_outputs(ctx, recipients, N_TX_OUTPUTS);
+        ret = secp256k1_silentpayments_test_outputs(
+            ctx, 
+            recipients, 
+            N_TX_OUTPUTS, 
+            out_pubkeys, 
+            n_out_pubkeys
+        );
         assert(ret);
+
+        printf("out_pubkeys: ");
+        print_hex(out_pubkeys, n_out_pubkeys);
 
         ret = secp256k1_silentpayments_sender_create_outputs(ctx,
             generated_output_ptrs,

include/secp256k1_silentpayments.h

@@ -110,7 +110,9 @@ SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_silentpayments_sender_c
 SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_silentpayments_test_outputs(
     const secp256k1_context *ctx,
     const secp256k1_silentpayments_recipient *recipients,
-    size_t n_recipients
+    size_t n_recipients,
+    unsigned char *out_pubkeys,
+    size_t n_out_pubkeys
 ) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2);
 
 /** Create Silent Payment label tweak and label.

src/modules/silentpayments/main_impl.h

@@ -139,54 +139,63 @@ static int secp256k1_silentpayments_create_output_pubkey(const secp256k1_context
     return ret;
 }
 
-static void print_hex(unsigned char* data, size_t size) {
+/* static void print_hex(unsigned char* data, size_t size) {
     size_t i;
     printf("0x");
     for (i = 0; i < size; i++) {
         printf("%02x", data[i]);
     }
     printf("\n");
-}
+} */
 
 int secp256k1_silentpayments_test_outputs(
     const secp256k1_context *ctx,
     const secp256k1_silentpayments_recipient *recipients,
-    size_t n_recipients
+    size_t n_recipients,
+    unsigned char *out_pubkeys,
+    size_t n_out_pubkeys
 ) {
     size_t i;
     int ret = 1;
 
+    VERIFY_CHECK(n_out_pubkeys == 66 * n_recipients);
 
     for (i = 0; i < n_recipients; i++) {
         ARG_CHECK(recipients[i].index == i);
     }
 
+    /* Initialize out_pubkeys to zero */
+    memset(out_pubkeys, 0, n_out_pubkeys);
+
     for (i = 0; i < n_recipients; i++) {
-        unsigned char compressed_scan_pubkey[33];
-        unsigned char compressed_spend_pubkey[33];
+        unsigned char *compressed_scan_pubkey = &out_pubkeys[i * 66];
+        unsigned char *compressed_spend_pubkey = &out_pubkeys[i * 66 + 33];
+
         size_t len;
 
-        printf("index: %ld\n", recipients[i].index);
+        // printf("index: %ld\n", recipients[i].index);
 
         /* Serialize pubkey1 in a compressed form (33 bytes), should always return 1 */
-        len = sizeof(compressed_scan_pubkey);
+        len = 33;
         ret = secp256k1_ec_pubkey_serialize(ctx, compressed_scan_pubkey, &len, &recipients[i].scan_pubkey, SECP256K1_EC_COMPRESSED);
         /* Should be the same size as the size of the output, because we passed a 33 byte array. */
-        VERIFY_CHECK(len == sizeof(compressed_scan_pubkey));
+        VERIFY_CHECK(len == 33);
 
-        len = sizeof(compressed_spend_pubkey);
+        len = 33;
         ret = secp256k1_ec_pubkey_serialize(ctx, compressed_spend_pubkey, &len, &recipients[i].spend_pubkey, SECP256K1_EC_COMPRESSED);
         /* Should be the same size as the size of the output, because we passed a 33 byte array. */
-        VERIFY_CHECK(len == sizeof(compressed_spend_pubkey));
+        VERIFY_CHECK(len == 33);
 
-        printf("scan_pubkey: ");
-        print_hex(compressed_scan_pubkey, sizeof(compressed_scan_pubkey));
+        // printf("scan_pubkey: ");
+        // print_hex(compressed_scan_pubkey, 33);
 
-        printf("spend_pubkey: ");
-        print_hex(compressed_spend_pubkey, sizeof(compressed_spend_pubkey));
+        // printf("spend_pubkey: ");
+        // print_hex(compressed_spend_pubkey, 33);
 
     }
 
+    VERIFY_CHECK((i * 66) == n_out_pubkeys);
+
     return ret;
 }