uor-addr-c

C ABI bindings for uor-addr — typed content-addressing exposed over extern "C" so embedded toolchains and any language with a C FFI can mint the same 71-byte sha256:<64hex> κ-label that the Rust crate produces, byte-for-byte.

What this crate is

A thin extern "C" marshalling layer over the uor-addr core. The core is no_std + no_alloc; this crate inherits that posture. The staticlib / cdylib outputs:

target/<profile>/libuor_addr_c.a — for embedded toolchains
target/<profile>/libuor_addr_c.so (.dylib on macOS, .dll on Windows) — for hosted FFI consumers

Plus a generated C header at include/uor_addr.h (auto-generated by cbindgen in build.rs — do not edit by hand).

API shape

Every UOR-ADDR realization is exposed as one entry point:

int32_t uor_addr_<realization>(
    const uint8_t *input,
    size_t         input_len,
    uint8_t       *out_label,
    size_t         out_label_len,
    size_t        *out_written);

Return value is one of:

Constant	Meaning
`UOR_ADDR_OK` (`0`)	Success; `out_label[..71]` holds the ASCII `sha256:<64hex>` κ-label.
`UOR_ADDR_ERR_NULL_POINTER` (`-1`)	`input == NULL && input_len > 0`, or `out_label == NULL`.
`UOR_ADDR_ERR_BUFFER_TOO_SMALL` (`-2`)	`out_label_len < 71`.
`UOR_ADDR_ERR_INVALID_INPUT` (`-3`)	Input failed the realization's host-boundary parser.
`UOR_ADDR_ERR_TOO_LARGE` (`-4`)	Input exceeded a typed-input ceiling.
`UOR_ADDR_ERR_PIPELINE` (`-5`)	Defensive substrate-level failure; unreachable on well-formed input.

Exported entry points:

Symbol	Realization
`uor_addr_json`	JSON (RFC 8259 + RFC 8785 JCS + UAX #15 NFC)
`uor_addr_sexp`	S-expressions (Rivest 1997 canonical form)
`uor_addr_xml`	XML (W3C XML-C14N 1.1 subset)
`uor_addr_asn1`	ASN.1 (ITU-T X.690 DER)
`uor_addr_ring`	Ring elements (UOR-Framework Amendment 43 §2)
`uor_addr_codemodule`	CCMAS canonical AST
`uor_addr_schema_photo`	schema.org/Photograph
`uor_addr_schema_document`	schema.org/Article (+ standard subtypes)
`uor_addr_schema_codemodule_signed`	in-toto Statement v1

Byte identity

The κ-label produced by this binding is byte-for-byte identical to uor_addr::<realization>::address(input).address. Callers can cross-check against the pure-Rust path; the FFI is a thin marshalling layer on top of the same no_alloc pipeline.

Building

# Default (no_std + no_alloc, embedded-friendly):
cargo build -p uor-addr-c --release

# Hosted (links libc, std panic handler):
cargo build -p uor-addr-c --release --features std

The C header at include/uor_addr.h regenerates on every build via the build.rs cbindgen invocation.

Consuming from other languages

The C ABI is the substrate for any language with a C FFI:

Language	Mechanism
C / C++	`#include "uor_addr.h"` + link `libuor_addr_c.a`
Python	`cffi` or `ctypes`
Go	`cgo`
Ruby	`FFI` gem
.NET	`P/Invoke`
Swift	C interop in Swift package manifests
Java / Kotlin	JNI shim around the C ABI

License

Apache-2.0 — same as uor-addr.