224a95f124
Cherry-picked from libfido2 upstream f20a735c0a6f: iso7816: Avoid storing pointers in a packed structure On CHERI, and thus Arm's experimental Morello prototype architecture, pointers are represented as capabilities, which are unforgeable bounded pointers, providing always-on fine-grained spatial memory safety. The unforgeability is enforced through the use of tagged memory, with one validity tag bit per capability-sized-and-aligned word in memory. This means that storing a pointer to an unaligned location, which is not guaranteed to work per the C standard, either traps or results in the capability losing its tag (and thus never being dereferenceable again), depending on how exactly the store is done (specifically, whether a capability store or memcpy is used). However, iso7816 itself does not need to be packed, and doing so likely causes inefficiencies on existing architectures. The iso7816_header_t member is packed, and the flexible payload array is a uint8_t (which by definition has no padding bits and is exactly 8 bits in size and, since CHAR_BITS must be at least 8, its existence implies that it has the same representation as unsigned char, and that it has size and alignment 1) so there will never be any padding inserted between header and payload (but payload may overlap with padding at the end of the struct due to how flexible arrays work, which means we need to be careful about our calculations). Co-authored-by: pedro martelletto <pedro@yubico.com> |
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examples | ||
fuzz | ||
man | ||
openbsd-compat | ||
regress | ||
src | ||
tools | ||
udev | ||
windows | ||
CMakeLists.txt | ||
LICENSE | ||
NEWS | ||
README.adoc |
== libfido2 image:https://github.com/yubico/libfido2/workflows/linux/badge.svg["Linux Build Status (github actions)", link="https://github.com/Yubico/libfido2/actions"] image:https://github.com/yubico/libfido2/workflows/macos/badge.svg["macOS Build Status (github actions)", link="https://github.com/Yubico/libfido2/actions"] image:https://github.com/yubico/libfido2/workflows/windows/badge.svg["Windows Build Status (github actions)", link="https://github.com/Yubico/libfido2/actions"] image:https://github.com/yubico/libfido2/workflows/fuzzer/badge.svg["Fuzz Status (github actions)", link="https://github.com/Yubico/libfido2/actions"] image:https://oss-fuzz-build-logs.storage.googleapis.com/badges/libfido2.svg["Fuzz Status (oss-fuzz)", link="https://bugs.chromium.org/p/oss-fuzz/issues/list?sort=-opened&can=1&q=proj:libfido2"] *libfido2* provides library functionality and command-line tools to communicate with a FIDO device over USB, and to verify attestation and assertion signatures. *libfido2* supports the FIDO U2F (CTAP 1) and FIDO 2.0 (CTAP 2) protocols. For usage, see the `examples/` directory. === License *libfido2* is licensed under the BSD 2-clause license. See the LICENSE file for the full license text. === Supported Platforms *libfido2* is known to work on Linux, macOS, Windows, OpenBSD, and FreeBSD. === Documentation Documentation is available in troff and HTML formats. An https://developers.yubico.com/libfido2/Manuals/[online mirror of *libfido2*'s documentation] is also available. === Bindings * .NET: https://github.com/borrrden/Fido2Net[Fido2Net] * Go: https://github.com/keys-pub/go-libfido2[go-libfido2] * Perl: https://github.com/jacquesg/p5-FIDO-Raw[p5-FIDO-Raw] * Rust: https://github.com/PvdBerg1998/libfido2[libfido2] === Installation ==== Releases The current release of *libfido2* is 1.8.0. Please consult Yubico's https://developers.yubico.com/libfido2/Releases[release page] for source and binary releases. ==== Ubuntu 20.04 (Focal) $ sudo apt install libfido2-1 $ sudo apt install libfido2-dev $ sudo apt install libfido2-doc Alternatively, newer versions of *libfido2* are available in Yubico's PPA. Follow the instructions for Ubuntu 18.04 (Bionic) below. ==== Ubuntu 18.04 (Bionic) $ sudo apt install software-properties-common $ sudo apt-add-repository ppa:yubico/stable $ sudo apt update $ sudo apt install libfido2-dev ==== macOS $ brew install libfido2 Or from source, on UNIX-like systems: $ (rm -rf build && mkdir build && cd build && cmake ..) $ make -C build $ sudo make -C build install Depending on the platform, https://www.freedesktop.org/wiki/Software/pkg-config/[pkg-config] may need to be installed, or the PKG_CONFIG_PATH environment variable set. *libfido2* depends on https://github.com/pjk/libcbor[libcbor], https://www.openssl.org[OpenSSL], and https://zlib.net[zlib]. On Linux, libudev (part of https://www.freedesktop.org/wiki/Software/systemd[systemd]) is also required. For complete, OS-specific installation instructions, please refer to the `.actions/` (Linux, macOS) and `windows/` directories. On Linux, you will need to add a udev rule to be able to access the FIDO device, or run as root. For example, the udev rule may contain the following: ---- #udev rule for allowing HID access to Yubico devices for FIDO support. KERNEL=="hidraw*", SUBSYSTEM=="hidraw", \ MODE="0664", GROUP="plugdev", ATTRS{idVendor}=="1050" ----