582246c8e6
Add partial support for SSH known hosts markers ### What does this PR try to resolve? The SSH `known_hosts` file parsing in Cargo did not previously support markers. Markers are modifiers on the lines (``@cert-authority`` and ``@revoked`)` which denote special behavior for the details on that line. Lines were skipped entirely. This silent skipping of marker lines can be confusing to a user, who sees that their command line Git/SSH client works for some repository, but Cargo reports that no host key is found. This change adds support for the ``@revoked`` marker. This marker denotes that a key should be rejected outright. It is of limited use without ``@cert-authority`` marker support. However, if it is present in a user's `known_hosts` file, then Cargo definitely shouldn't accept that key and probably shouldn't suggest that the user add it to their `known_hosts` either. The change also adds support for detecting ``@cert-authority`` markers in `known_hosts` files. These lines cannot yet be used for host key verification, but if one is found for a matching host, the user will be informed that Cargo doesn't support ``@cert-authority`` markers in the error message. Additionally, the user will be advised to use the `net.git-fetch-with-cli` config option to use the command line git client for fetching crates from Git. Refs: #11577 ### How should we test and review this PR? The changes in this PR are covered by unit tests, all within `src/cargo/sources/git/known_hosts.rs`. Additionally, manual testing can be performed. For this you will need an OpenSSH server (it doesn't need to be a Git server). I'll assume that you have one running on your local machine at `127.0.0.1`. #### Setup 1. Create a new Cargo project and add the following line to `[dependencies]`: ```toml fake-crate = { git = "ssh://127.0.0.1/fake-crate.git" } ``` #### Test missing host key: `HostKeyNotFound` (existing functionality) 1. Back up your `known_hosts` file and then remove any lines for `127.0.0.1`. 2. Verify host key not present: `ssh 127.0.0.1`. SSH should tell you `The authenticity of host '127.0.0.1 (127.0.0.1)' can't be established.` 3. Run `cargo build` 4. Expect error from Cargo: `error: unknown SSH host key` #### Test ``@revoked`` key: `HostKeyRevoked` 1. Back up your `known_hosts` file and then remove any lines for `127.0.0.1`. 2. Add host key: `ssh 127.0.0.1` answer `yes` 3. Find all lines in `known_hosts` beginning with `127.0.0.1` (there may be multiple). 4. Add ``@revoked` ` to the beginning of all lines in (3) 5. Run `cargo build` 6. Expect error from Cargo: error: Key has been revoked for `127.0.0.1` #### Test `@cert-authority`` (not being supported): `HostHasOnlyCertAuthority` 1. Back up your `known_hosts` file and then remove any lines for `127.0.0.1`. 2. Run `cargo build` 3. Expect error from Cargo: `error: unknown SSH host key` 4. Check the line after ` The key to add is:` in the error message and copy the key type (e.g. `ecdsa-sha2-nistp256`) 5. Add a line to `known_hosts`: ``@cert-authority` 127.0.0.1 <key-type> AAAAB5Wm` (e.g. ``@cert-authority` 127.0.0.1 ecdsa-sha2-nistp256 AAAAB5Wm`) 7. Run `cargo build` 8. Expect error from Cargo: error: Found a ``@cert-authority`` marker for `127.0.0.1` ### Additional information Cargo doesn't currently support a few things when checking host keys. This may affect the testing described above. * Multiple host key types (OpenSSH negotiates the host key type and can support matching the one present in the `known_hosts` file even when it's not the preferred type of the server). * Wildcard matching of host patterns (there's a FIXME for this) More information about SSH known host markers can be found on #11577.
Cargo
Cargo downloads your Rust project’s dependencies and compiles your project.
To start using Cargo, learn more at The Cargo Book.
To start developing Cargo itself, read the Cargo Contributor Guide.
Code Status
Code documentation: https://docs.rs/cargo/
Installing Cargo
Cargo is distributed by default with Rust, so if you've got rustc installed
locally you probably also have cargo installed locally.
Compiling from Source
Requirements
Cargo requires the following tools and packages to build:
cargoandrustc- A C compiler for your platform
git(to clone this repository)
Other requirements:
The following are optional based on your platform and needs.
-
pkg-config— This is used to help locate system packages, such aslibsslheaders/libraries. This may not be required in all cases, such as using vendored OpenSSL, or on Windows. -
OpenSSL — Only needed on Unix-like systems and only if the
vendored-opensslCargo feature is not used.This requires the development headers, which can be obtained from the
libssl-devpackage on Ubuntu oropenssl-develwith apk or yum or theopensslpackage from Homebrew on macOS.If using the
vendored-opensslCargo feature, then a static copy of OpenSSL will be built from source instead of using the system OpenSSL. This may require additional tools such asperlandmake.On macOS, common installation directories from Homebrew, MacPorts, or pkgsrc will be checked. Otherwise it will fall back to
pkg-config.On Windows, the system-provided Schannel will be used instead.
LibreSSL is also supported.
Optional system libraries:
The build will automatically use vendored versions of the following libraries. However, if they are provided by the system and can be found with pkg-config, then the system libraries will be used instead:
libcurl— Used for network transfers.libgit2— Used for fetching git dependencies.libssh2— Used for SSH access to git repositories.libz(aka zlib) — Used for data compression.
It is recommended to use the vendored versions as they are the versions that are tested to work with Cargo.
Compiling
First, you'll want to check out this repository
git clone https://github.com/rust-lang/cargo.git
cd cargo
With cargo already installed, you can simply run:
cargo build --release
Adding new subcommands to Cargo
Cargo is designed to be extensible with new subcommands without having to modify Cargo itself. See the Wiki page for more details and a list of known community-developed subcommands.
Releases
Cargo releases coincide with Rust releases. High level release notes are available as part of Rust's release notes. Detailed release notes are available in this repo at CHANGELOG.md.
Reporting issues
Found a bug? We'd love to know about it!
Please report all issues on the GitHub issue tracker.
Contributing
See the Cargo Contributor Guide for a complete introduction to contributing to Cargo.
License
Cargo is primarily distributed under the terms of both the MIT license and the Apache License (Version 2.0).
See LICENSE-APACHE and LICENSE-MIT for details.
Third party software
This product includes software developed by the OpenSSL Project for use in the OpenSSL Toolkit (https://www.openssl.org/).
In binary form, this product includes software that is licensed under the terms of the GNU General Public License, version 2, with a linking exception, which can be obtained from the upstream repository.
See LICENSE-THIRD-PARTY for details.