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`selectBranch` reads the key byte at `depth / 2`, which is out of bounds for a 32-byte key once the depth reaches 64. Every branch selection in the map funnels through here, so this is the one place a stray depth can turn into a bad read. Assert the precondition for callers, then clamp anyway: a wrong answer for an input that should never occur is better than reading past the buffer. Verified under ASan that the unclamped form reads one byte past a 32-byte allocation while the clamped form does not. `depthMask`'s own 65-entry table had the same exposure one level up, reachable through the public `createID` factory rather than only from inside the map. A depth past `kLeafDepth` indexed that table out of bounds, confirmed under ASan as a 4-byte `global-buffer-overflow` immediately after `kMasks`. Both places that can set a depth now clamp it: the constructor, which is the single point every `SHAMapNodeID`'s `depth_` passes through, and `createID`, which needs its own bound because it picks the mask while evaluating the constructor's argument, before the constructor body could correct anything. Clamping rather than throwing, which is what `getChildNodeID` does for the analogous case: `createID` is reached from `getSHAMapNodeID` with a peer-supplied depth, and two of that function's three callers (`InboundTransactions::gotData`, `PeerImp::onMessage`) sit on paths with no handler between them and a thread boundary, so a throw there would end the process rather than the message. Clamping also has to fix up `id_` alongside `depth_`, since a node ID whose id and depth disagree fails the invariant every read of `id_` relies on. Leaving the depth unclamped would additionally let `getRawString` narrow it to a byte, turning depth 256 into a node claiming to be the root. `deserializeSHAMapNodeID` gets the same mask check `isPrefixOf` already performs, pulled into a shared `isPrefixOfAtDepth` helper, and the masking both it and `createID` perform is now a named `maskedToDepth` rather than a repeated bitwise-and. Tests cover the depth-sensitivity of `isPrefixOf`, the guards that must hold with asserts stripped, that `deserializeSHAMapNodeID` rejects an out-of-range depth, and the clamp itself under both build configurations (`EXPECT_DEATH` in a forked process when the assert is live, and the clamped result compared against depth 63 when it is not). The clamp test also gates on `ENABLE_VOIDSTAR`, not just `NDEBUG`: under Antithesis instrumentation `XRPL_ASSERT` routes to a handler that records the hit but never aborts, so a Debug build with voidstar enabled has `NDEBUG` undefined yet still hits the same non-fatal assert as a release build, and without this gate would send that configuration into the `EXPECT_DEATH` arm, where the forked child never dies and the test fails, breaking the CI job that runs this suite under `-Dvoidstar=ON`.
The XRP Ledger
The XRP Ledger is a decentralized cryptographic ledger powered by a network of peer-to-peer nodes. The XRP Ledger uses a novel Byzantine Fault Tolerant consensus algorithm to settle and record transactions in a secure distributed database without a central operator.
XRP
XRP is a public, counterparty-free crypto-asset native to the XRP Ledger, and is designed as a gas token for network services and to bridge different currencies. XRP is traded on the open-market and is available for anyone to access. The XRP Ledger was created in 2012 with a finite supply of 100 billion units of XRP.
xrpld
The server software that powers the XRP Ledger is called xrpld and is available in this repository under the permissive ISC open-source license. The xrpld server software is written primarily in C++ and runs on a variety of platforms. The xrpld server software can run in several modes depending on its configuration.
If you are interested in running an API Server (including a Full History Server), take a look at Clio. (xrpld Reporting Mode has been replaced by Clio.)
Build from Source
- Read the build instructions in
BUILD.md - If you encounter any issues, please open an issue
Key Features of the XRP Ledger
- Censorship-Resistant Transaction Processing: No single party decides which transactions succeed or fail, and no one can "roll back" a transaction after it completes. As long as those who choose to participate in the network keep it healthy, they can settle transactions in seconds.
- Fast, Efficient Consensus Algorithm: The XRP Ledger's consensus algorithm settles transactions in 4 to 5 seconds, processing at a throughput of up to 1500 transactions per second. These properties put XRP at least an order of magnitude ahead of other top digital assets.
- Finite XRP Supply: When the XRP Ledger began, 100 billion XRP were created, and no more XRP will ever be created. The available supply of XRP decreases slowly over time as small amounts are destroyed to pay transaction fees.
- Responsible Software Governance: A team of full-time developers at Ripple & other organizations maintain and continually improve the XRP Ledger's underlying software with contributions from the open-source community. Ripple acts as a steward for the technology and an advocate for its interests.
- Secure, Adaptable Cryptography: The XRP Ledger relies on industry standard digital signature systems like ECDSA (the same scheme used by Bitcoin) but also supports modern, efficient algorithms like Ed25519. The extensible nature of the XRP Ledger's software makes it possible to add and disable algorithms as the state of the art in cryptography advances.
- Modern Features: Features like Escrow, Checks, and Payment Channels support financial applications atop of the XRP Ledger. This toolbox of advanced features comes with safety features like a process for amending the network and separate checks against invariant constraints.
- On-Ledger Decentralized Exchange: In addition to all the features that make XRP useful on its own, the XRP Ledger also has a fully-functional accounting system for tracking and trading obligations denominated in any way users want, and an exchange built into the protocol. The XRP Ledger can settle long, cross-currency payment paths and exchanges of multiple currencies in atomic transactions, bridging gaps of trust with XRP.
Source Code
Here are some good places to start learning the source code:
- Read the markdown files in the source tree:
src/xrpld/**/*.md. - Read the levelization document to get an idea of the internal dependency graph.
- In the big picture, the
mainfunction constructs anApplicationImpobject, which implements theApplicationvirtual interface. Almost every component in the application takes anApplication¶meter in its constructor, typically namedappand stored as a member variableapp_. This allows most components to depend on any other component.
Repository Contents
| Folder | Contents |
|---|---|
./bin |
Scripts and data files for XRPL developers. |
./Builds |
Platform-specific guides for building xrpld. |
./docs |
Source documentation files and doxygen config. |
./cfg |
Example configuration files. |
./src |
Source code. |
Some of the directories under src are external repositories included using
git-subtree. See those directories' README files for more details.