BITCOIN MAINNETLive explorer status

Explorer Mempool Feed Forum Visualizer Receipts Tools Learn Code

Inside Bitcoin

Opening the selected file…

₿MyBitcoinExplorer

Bitcoin, in focus.
Explore the network. Understand the connections.

Explore Bitcoin with clarity.

READ THE CODE

Inside Bitcoin

The code behind the network, with room to understand it.

Stable release v32.1bitcoin/bitcoin · f0de87f04062 ↗3,020 source files · 47.5 MB stored on the server440 file guides

Release published 2026-10-28 · Snapshot fetched 2026-11-01. Latest stable release at fetch time; development branches and Git history are excluded. Only the selected code window and visible folders load here.

bitcoin / bitcoinstable

Find a file

▤ arith_uint256.hGuide

▤ bitcoin-chainstate.cpp

▤ bitcoin-cli-res.rc

▤ bitcoin-cli.cppGuide

▤ bitcoin-res.rc

▤ bitcoin-tx-res.rc

▤ bitcoin-tx.cpp

▤ bitcoin-util-res.rc

▤ bitcoin-util.cpp

▤ bitcoin-wallet-res.rc

▤ blockencodings.cppGuide

▤ blockencodings.hGuide

▤ blockfilter.cppGuide

▤ blockfilter.hGuide

▤ chain.cppGuide

▤ chain.h

▤ chainparams.cppGuide

▤ chainparams.hGuide

▤ chainparamsbase.cppGuide

▤ chainparamsbase.hGuide

▤ chainparamsseeds.h

▤ checkqueue.hGuide

▤ clientversion.cppGuide

▤ clientversion.hGuide

▤ cluster_linearize.h

▤ CMakeLists.txt

▤ coins.cppGuide

▤ coins.hGuide

▤ compressor.cppGuide

▤ compressor.hGuide

▤ core_io.cpp

▤ core_io.hGuide

▤ core_memusage.hGuide

▤ cuckoocache.h

▤ dbwrapper.cpp

▤ dbwrapper.hGuide

▤ deploymentinfo.cppGuide

▤ deploymentinfo.hGuide

▤ deploymentstatus.cppGuide

▤ deploymentstatus.hGuide

▤ dummywallet.cppGuide

▤ external_signer.cpp

▤ external_signer.hGuide

▤ merkleblock.cppGuide

▤ merkleblock.hGuide

▤ musig.cpp

▤ musig.hGuide

▤ net_permissions.cppGuide

▤ net_permissions.hGuide

▤ net_processing.cppGuide

▤ netaddress.cppGuide

▤ netmessagemaker.hGuide

▤ noui.cppGuide

▤ noui.hGuide

▤ outputtype.cppGuide

▤ private_broadcast.cpp

▤ private_broadcast.h

▤ semaphore_grant.hGuide

▤ threadsafety.hGuide

▤ tinyformat.h

▤ torcontrol.cppGuide

▤ validation.cppGuide

▤ validation.h

▤ validationinterface.cpp

▤ validationinterface.h

▤ versionbits_impl.hGuide

▤ versionbits.cpp

▤ versionbits.hGuide

▤ walletinitinterface.hGuide

▤ CMakeLists.txtGuide

▤ libbitcoinkernel.pc.in

bitcoin / src / secp256k1 / examples / silentpayments.c

Download source ↓

19,628 bytes · SHA-256 b31e7e1f197e2386… · View upstream ↗

251        }
252        /*** Create the recipient objects ***/
253
254        /* Alice is sending to Bob and Carol in this transaction:
255         *
256         *     1. One output to Bob's labeled address
257         *     2. Two outputs for Carol
258         *
259         * To create multiple outputs for Carol, Alice simply passes Carol's
260         * Silent Payments address multiple times.
261         */
262        sp_addresses[0] = &carol_address;
263        sp_addresses[1] = &bob_address;
264        sp_addresses[2] = &carol_address;
265        for (i = 0; i < N_OUTPUTS; i++) {
266            ret = secp256k1_ec_pubkey_parse(ctx,
267                &recipients[i].scan_pubkey,
268                (*(sp_addresses[i]))[0],
269                33
270            );
271            ret &= secp256k1_ec_pubkey_parse(ctx,
272                &recipients[i].spend_pubkey,
273                (*(sp_addresses[i]))[1],
274                33
275            );
276            if (!ret) {
277                printf("Something went wrong, this is not a valid Silent Payments address.\n");
278                return EXIT_FAILURE;
279            }
280
281            /* Alice creates the recipient objects and adds the index of the
282             * original ordering (the ordering of the `sp_addresses` array) to
283             * each object. This index is used to return the generated outputs
284             * in the original ordering so that Alice can match up the generated
285             * outputs with the correct amounts.
286             */
287            recipients[i].index = i;
288            recipient_ptrs[i] = &recipients[i];
289        }
290        ret = secp256k1_silentpayments_sender_create_outputs(ctx,
291            tx_output_ptrs,
292            recipient_ptrs, N_OUTPUTS,
293            smallest_outpoint,
294            sender_keypair_ptrs, N_INPUTS,
295            NULL, 0
296        );
297        if (!ret) {
298            printf("Something went wrong, group limit exceeded or input secret keys sum to zero.\n");
299            return EXIT_FAILURE;
300        }
301        printf("Alice created the following outputs for Bob and Carol:\n");
302        for (i = 0; i < N_OUTPUTS; i++) {
303            printf("    ");
304            ret = secp256k1_xonly_pubkey_serialize(ctx,
305                serialized_xonly,
306                &tx_outputs[i]
307            );
308            assert(ret);
309            print_hex(serialized_xonly, sizeof(serialized_xonly));
310        }
311        /* It's best practice to try to clear secrets from memory after using
312         * them. This is done because some bugs can allow an attacker to leak
313         * memory, for example through "out of bounds" array access (see
314         * Heartbleed), or the OS swapping them to disk. Hence, we overwrite the
315         * secret key buffer with zeros.
316         *
317         * Here we are preventing these writes from being optimized out, as any
318         * good compiler will remove any writes that aren't used. */
319        secure_erase(seckey, sizeof(seckey));
320        for (i = 0; i < N_INPUTS; i++) {
321            secure_erase(&sender_keypairs[i], sizeof(sender_keypairs[i]));
322        }
323    }
324
325    /*** Receiving ***/
326    {
327        {
328            /*** Scanning as a full node (Bob) ***
329             *
330             * Since Bob has access to the full transaction, scanning is simple:
331             *
332             *     1. Collect the relevant prevouts from the transaction and call
333             *        `secp256k1_silentpayments_recipient_prevouts_summary_create`
334             *     2. Call `secp256k1_silentpayments_recipient_scan_outputs`
335             */
336            ret = secp256k1_silentpayments_recipient_prevouts_summary_create(ctx,
337                &prevouts_summary,
338                smallest_outpoint,
339                tx_input_ptrs, N_INPUTS,
340                NULL, 0
341            );
342            if (!ret) {
343                /* We need to always check that the prevouts data object is valid
344                 * before proceeding.
345                 */
346                printf("This transaction is not valid for Silent Payments, skipping.\n");
347                return EXIT_SUCCESS;
348            }
349
350            /* Scan the transaction */
351            n_found_outputs = 0;
352            ret = secp256k1_silentpayments_recipient_scan_outputs(ctx,
353                found_output_ptrs, &n_found_outputs,
354                (const secp256k1_xonly_pubkey**)tx_output_ptrs, N_OUTPUTS,
355                bob_scan_key,
356                &prevouts_summary,
357                &unlabeled_spend_pubkey,
358                label_lookup, &bob_labels_cache /* NULL, NULL for no labels */
359            );
360            if (!ret) {
361                printf("This transaction is not valid for Silent Payments, skipping.\n");
362                return EXIT_SUCCESS;
363            }
364            if (n_found_outputs > 0) {
365                secp256k1_keypair kp;
366                secp256k1_xonly_pubkey xonly_output;
367                unsigned char full_seckey[32];
368
369                printf("\n");
370                printf("Bob found the following outputs: \n");
371                for (i = 0; i < n_found_outputs; i++) {
372                    printf("    ");
373                    ret = secp256k1_xonly_pubkey_serialize(ctx,
374                        serialized_xonly,
375                        &found_outputs[i].output
376                    );
377                    assert(ret);
378                    print_hex(serialized_xonly, sizeof(serialized_xonly));
379
380                    /* Verify that this output is spendable by Bob by reconstructing the full
381                     * secret key for the xonly output.
382                     *
383                     * This is done by adding the tweak from the transaction to Bob's spend key.
384                     * If the output was sent to a labeled address, the label tweak has already
385                     * been added to the tweak in `secp256k1_silentpayments_found_output`.
386                     *
387                     * To verify that we are able to sign for this output, it is sufficient to
388                     * check that the public key generated from `full_seckey` matches the output
389                     * in the transaction. For a full example on signing for a taproot ouput,
390                     * see `examples/schnorr.c`.
391                     */
392                    memcpy(&full_seckey, &bob_spend_key, 32);
393                    ret = secp256k1_ec_seckey_tweak_add(ctx, full_seckey, found_outputs[i].tweak);
394                    ret &= secp256k1_keypair_create(ctx, &kp, full_seckey);
395                    ret &= secp256k1_keypair_xonly_pub(
396                        ctx,
397                        &xonly_output,
398                        NULL,
399                        &kp
400                    );
401                    /* We assert here because the only way the seckey_tweak_add operation can fail
402                     * is if the tweak is the negation of Bob's spend key.
403                     *
404                     * We also assert that the generated public key matches the transaction output,
405                     * as it should be impossible for a mismatch at this point considering the
406                     * scanning function completed without errors and indicated found outputs.
407                     */
408                    assert(ret);
409                    assert(secp256k1_xonly_pubkey_cmp(ctx, &xonly_output, &found_outputs[i].output) == 0);
410                    secure_erase(full_seckey, sizeof(full_seckey));
411                }
412            } else {
413                printf("Bob did not find any outputs in this transaction.\n");
414            }
415        }
416        {
417            /*** Scanning as a full node (Carol) ***/
418            /* TODO: switch this part to light client scanning once it is supported */
419
420            /* Load Carol's spend public key. */
421            ret = secp256k1_ec_pubkey_parse(ctx,
422                &unlabeled_spend_pubkey,
423                carol_address[1],
424                33
425            );
426            assert(ret);
427
428            n_found_outputs = 0;
429            ret = secp256k1_silentpayments_recipient_scan_outputs(ctx,
430                found_output_ptrs, &n_found_outputs,
431                (const secp256k1_xonly_pubkey**)tx_output_ptrs, N_OUTPUTS,
432                carol_scan_key,
433                &prevouts_summary,
434                &unlabeled_spend_pubkey,
435                NULL, NULL /* NULL, NULL for no labels */
436            );
437            if (!ret) {
438                printf("This transaction is not valid for Silent Payments, skipping.\n");
439                return EXIT_SUCCESS;
440            }
441            if (n_found_outputs > 0) {
442                /* Carol would spend these outputs the same as Bob, by tweaking her
443                 * spend key with the tweak corresponding to the found output. See above
444                 * for an example for Bob's outputs. */
445                printf("\n");
446                printf("Carol found the following outputs: \n");
447                for (i = 0; i < n_found_outputs; i++) {
448                    printf("    ");
449                    ret = secp256k1_xonly_pubkey_serialize(ctx,
450                        serialized_xonly,
451                        &found_outputs[i].output
452                    );
453                    assert(ret);
454                    print_hex(serialized_xonly, sizeof(serialized_xonly));
455                }
456            } else {
457                printf("Carol did not find any outputs in this transaction.\n");
458            }
459        }
460    }
461
462    /* This will clear everything from the context and free the memory */
463    secp256k1_context_destroy(ctx);
464    return EXIT_SUCCESS;
465}
466

A READING COMPANION

Source available. Guide coming next.

This file is included in the stable source snapshot. A file-specific guide has not been published yet.

440 guided files · 2,580 pending. Guides cover key sections, not every line.

cmake/bitcoin-build-config.h.in src/consensus/amount.h src/consensus/consensus.h src/primitives/block.h src/primitives/transaction.h src/crypto/sha256.h src/util/moneystr.h src/clientversion.h src/uint256.h src/script/script.h src/policy/policy.h CMakeLists.txt README.md COPYING src/consensus/tx_check.cpp src/consensus/tx_verify.cpp src/consensus/merkle.cpp src/pow.cpp src/validation.cpp src/script/interpreter.cpp src/script/solver.cpp src/script/sign.cpp src/key_io.cpp src/net.cpp src/net_processing.cpp src/netaddress.cpp src/protocol.h src/wallet/wallet.cpp src/wallet/spend.cpp

← Previous 250 linesCode page 2

src/wallet/receive.cpp

src/wallet/coinselection.cpp

src/consensus/validation.h

src/primitives/transaction.cpp

src/script/descriptor.cpp

src/bitcoin-cli.cpp

src/rpc/blockchain.cpp

src/rpc/rawtransaction.cpp

src/init.cpp

src/crypto/sha256.cpp

src/consensus/merkle.h

src/consensus/tx_check.h

src/consensus/tx_verify.h

src/policy/feerate.h

src/policy/feerate.cpp

src/primitives/transaction_identifier.h

src/chainparamsbase.h

src/chainparamsbase.cpp

src/util/moneystr.cpp

src/crypto/ripemd160.h

src/crypto/sha1.h

src/crypto/sha512.h

src/crypto/hmac_sha256.h

src/crypto/hmac_sha512.h

src/crypto/hmac_sha256.cpp

src/crypto/hmac_sha512.cpp

src/crypto/hkdf_sha256_32.h

src/crypto/hkdf_sha256_32.cpp

src/support/cleanse.h

src/support/cleanse.cpp

src/crypto/siphash.cpp

src/crypto/muhash.h

src/crypto/chacha20.h

src/crypto/poly1305.h

src/crypto/chacha20poly1305.h

src/crypto/chacha20poly1305.cpp

src/util/chaintype.cpp

src/util/obfuscation.h

src/util/byte_units.h

src/util/overflow.h

src/blockencodings.cpp

src/net_permissions.cpp

src/policy/packages.cpp

src/policy/rbf.cpp

src/policy/truc_policy.cpp

src/policy/ephemeral_policy.cpp

src/policy/settings.cpp

src/policy/policy.cpp

src/node/transaction.cpp

src/node/coin.cpp

src/rpc/client.cpp

src/rpc/external_signer.cpp

src/rpc/request.cpp

src/rpc/server_util.cpp

src/rpc/fees.cpp

src/rpc/output_script.cpp

src/rpc/rawtransaction_util.cpp

src/rpc/rawtransaction_util.h

src/rpc/register.h

src/rpc/request.h

src/rpc/server_util.h

src/rpc/protocol.h

src/rpc/server.h

src/rpc/signmessage.cpp

src/rpc/txoutproof.cpp

src/rpc/util.cpp

src/rpc/util.h

src/wallet/rpc/addresses.cpp

src/wallet/rpc/backup.cpp

src/wallet/rpc/coins.cpp

src/wallet/rpc/encrypt.cpp

src/wallet/rpc/signmessage.cpp

src/wallet/rpc/util.cpp

src/wallet/rpc/util.h

src/wallet/coincontrol.cpp

src/wallet/coincontrol.h

src/wallet/context.cpp

src/wallet/context.h

src/wallet/crypter.cpp

src/wallet/crypter.h

src/wallet/db.cpp

src/wallet/export.cpp

src/wallet/external_signer_scriptpubkeyman.cpp

src/wallet/rpc/spend.cpp

src/wallet/rpc/transactions.cpp

src/wallet/rpc/wallet.cpp

src/wallet/feebumper.cpp

src/wallet/feebumper.h

src/index/base.h

src/index/base.cpp

src/index/txindex.h

src/index/txindex.cpp

src/index/txindex_key.h

src/index/txospenderindex.h

src/index/txospenderindex.cpp

src/index/blockfilterindex.h

src/index/blockfilterindex.cpp

src/index/coinstatsindex.h

src/index/coinstatsindex.cpp

src/index/db_key.h

src/index/disktxpos.h

src/kernel/chain.cpp

src/kernel/chain.h

src/kernel/checks.cpp

src/kernel/checks.h

src/kernel/context.cpp

src/kernel/context.h

src/kernel/cs_main.cpp

src/kernel/cs_main.h

src/kernel/disconnected_transactions.cpp

src/kernel/disconnected_transactions.h

src/kernel/mempool_removal_reason.cpp

src/kernel/mempool_removal_reason.h

src/kernel/coinstats.cpp

src/kernel/coinstats.h

src/kernel/chainparams.cpp

src/kernel/chainparams.h

src/wallet/sqlite.cpp

src/wallet/sqlite.h

src/wallet/transaction.cpp

src/wallet/transaction.h

src/wallet/dump.cpp

src/wallet/dump.h

src/wallet/init.cpp

src/wallet/walletutil.cpp

src/wallet/walletutil.h

src/wallet/wallettool.cpp

src/wallet/wallettool.h

src/wallet/export.h

src/wallet/migrate.cpp

src/wallet/migrate.h

src/wallet/db.h

src/wallet/walletdb.cpp

src/wallet/interfaces.cpp

src/wallet/scriptpubkeyman.cpp

src/wallet/scriptpubkeyman.h

src/kernel/bitcoinkernel.cpp

src/kernel/bitcoinkernel.h

src/kernel/bitcoinkernel_wrapper.h

src/node/chainstate.cpp

src/node/chainstate.h

src/node/blockstorage.cpp

src/node/blockstorage.h

src/node/mempool_persist.cpp

src/node/mempool_persist.h

src/node/utxo_snapshot.cpp

src/node/utxo_snapshot.h

src/node/kernel_notifications.cpp

src/node/kernel_notifications.h

src/node/blockmanager_args.cpp

src/kernel/blockmanager_opts.h

src/util/expected.cpp

src/policy/settings.h

src/util/types.h

src/kernel/messagestartchars.h

src/kernel/warning.h

src/util/exception.h

src/common/license_info.h

src/node/coins_view_args.h

src/node/database_args.h

src/util/batchpriority.h

src/util/ui_change_type.h

src/node/coins_view_args.cpp

src/node/peerman_args.h

src/util/serfloat.h

src/node/blockmanager_args.h

src/node/database_args.cpp

src/util/overloaded.h

src/interfaces/types.h

src/node/chainstatemanager_args.h

src/node/minisketchwrapper.h

src/util/macros.h

src/util/syserror.h

src/common/run_command.h

src/util/bytevectorhash.cpp

src/node/mempool_persist_args.cpp

src/util/exec.h

src/util/rbf.h

src/crypto/hex_base.h

src/node/mempool_persist_args.h

src/interfaces/echo.h

src/util/any.h

src/util/batchpriority.cpp

src/util/threadnames.h

src/node/coin.h

src/node/mempool_args.h

src/util/asmap.h

src/util/bytevectorhash.h

src/node/context.cpp

src/util/insert.h

src/util/readwritefile.h

src/node/peerman_args.cpp

src/node/interface_ui.cpp

src/interfaces/handler.h

src/node/mining_args.h

src/util/hasher.cpp

src/common/init.h

src/kernel/mempool_limits.h

src/common/system.h

src/crypto/sha3.h

src/util/threadinterrupt.cpp

src/node/protocol_version.h

src/util/exception.cpp

src/common/messages.h

src/node/connection_types.cpp

src/util/bip32.h

src/common/license_info.cpp

src/util/stdmutex.h

src/common/run_command.cpp

src/util/check.cpp

src/util/golombrice.h

src/node/types.h

src/node/timeoffsets.h

src/util/readwritefile.cpp

src/util/fastrange.h

src/util/signalinterrupt.h

src/util/task_runner.h

src/util/syserror.cpp

src/common/interfaces.cpp

src/common/types.h

src/util/threadinterrupt.h

src/kernel/chainstatemanager_opts.h

src/node/psbt.h

src/policy/ephemeral_policy.h

src/util/trace.h

src/common/url.cpp

src/kernel/mempool_options.h

src/util/serfloat.cpp

src/kernel/notifications_interface.h

src/node/timeoffsets.cpp

src/node/warnings.cpp

src/util/hash_type.h

src/crypto/hex_base.cpp

src/node/eviction.h

src/util/tokenbucket.h

src/crypto/aes.h

src/common/pcp.h

src/util/feefrac.cpp

src/node/transaction.h

src/util/threadnames.cpp

src/common/signmessage.h

src/util/exec.cpp

src/util/signalinterrupt.cpp

src/clientversion.cpp

src/common/signmessage.cpp

src/compat/assumptions.h

src/compat/byteswap.h

src/deploymentinfo.cpp

src/deploymentinfo.h

src/deploymentstatus.cpp

src/deploymentstatus.h

src/dummywallet.cpp

src/external_signer.h

src/init/bitcoin-gui.cpp

src/init/bitcoin-node.cpp

src/init/bitcoin-qt.cpp

src/init/bitcoin-wallet.cpp

src/init/bitcoind.cpp

src/init/common.h

src/interfaces/init.h

src/interfaces/ipc.h

src/key_io.h

src/logging/categories.h

src/logging/timer.h

src/mapport.h

src/musig.h

src/net_permissions.h

src/netgroup.h

src/netmessagemaker.h

src/node/chainstatemanager_args.cpp

src/node/connection_types.h

src/node/context.h

src/node/interface_ui.h

src/node/mempool_args.cpp

src/node/mining_args.cpp

src/node/minisketchwrapper.cpp

src/node/txreconciliation.h

src/policy/fees/estimator_args.cpp

src/policy/fees/estimator_args.h

src/policy/fees/estimator_man.cpp

src/policy/fees/estimator_man.h

src/policy/packages.h

src/policy/rbf.h

src/policy/truc_policy.h

src/pow.h

src/primitives/block.cpp

src/randomenv.h

src/rest.h

src/script/keyorigin.h

src/script/parsing.cpp

src/script/parsing.h

src/script/script_error.h

src/script/sigcache.cpp

src/script/sigcache.h

src/script/solver.h

src/script/verify_flags.h

src/semaphore_grant.h

src/signet.h

src/span.h

src/support/allocators/secure.h

src/support/allocators/zeroafterfree.h

src/util/tokenpipe.cpp

src/util/translation.h

src/util/vector.h

src/versionbits.h

src/versionbits_impl.h

src/wallet/external_signer_scriptpubkeyman.h

src/wallet/fees.h

src/wallet/load.h

src/wallet/receive.h

src/wallet/rpc/wallet.h

src/wallet/types.h

src/walletinitinterface.h

src/zmq/zmqabstractnotifier.cpp

Independent explanations by MyBitcoinExplorer. Not affiliated with or endorsed by Bitcoin Core. Guides are educational and do not replace the source or its tests.

Bitcoin Core source © its contributors, distributed under the MIT license. Original notices and bundled third-party licenses are retained in the source tree.