feat: Added age-ffi.

zig-vendor/age-ffi/src/keys.rs

@@ -0,0 +1,92 @@
+//! Key generation and derivation functions.
+
+use crate::helpers::{cstr_to_str, string_to_cstr};
+use crate::types::{AgeKeypair, AgeResult};
+use age::secrecy::ExposeSecret;
+use std::ffi::CString;
+use std::os::raw::c_char;
+use std::str::FromStr;
+
+/// Generate a new age x25519 keypair.
+///
+/// # Arguments
+/// * `keypair` - Pointer to receive the generated keypair
+///
+/// # Returns
+/// AgeResult indicating success or failure
+#[no_mangle]
+pub extern "C" fn age_generate_x25519(keypair: *mut AgeKeypair) -> AgeResult {
+    if keypair.is_null() {
+        return AgeResult::InvalidInput;
+    }
+
+    let identity = age::x25519::Identity::generate();
+    let public_key = identity.to_public().to_string();
+    let private_key = identity.to_string().expose_secret().to_string();
+
+    let c_public = match string_to_cstr(public_key) {
+        Ok(s) => s,
+        Err(e) => return e,
+    };
+
+    let c_private = match string_to_cstr(private_key) {
+        Ok(s) => s,
+        Err(e) => {
+            unsafe { drop(CString::from_raw(c_public)); }
+            return e;
+        }
+    };
+
+    unsafe {
+        (*keypair).public_key = c_public;
+        (*keypair).private_key = c_private;
+    }
+
+    AgeResult::Success
+}
+
+/// Alias for age_generate_x25519 for backwards compatibility.
+#[no_mangle]
+pub extern "C" fn age_generate_keypair(keypair: *mut AgeKeypair) -> AgeResult {
+    age_generate_x25519(keypair)
+}
+
+/// Derive the public key from a private x25519 identity.
+///
+/// # Arguments
+/// * `private_key` - The private key string (AGE-SECRET-KEY-1...)
+/// * `public_key` - Pointer to receive the public key string
+///
+/// # Returns
+/// AgeResult indicating success or failure
+#[no_mangle]
+pub extern "C" fn age_x25519_to_public(
+    private_key: *const c_char,
+    public_key: *mut *mut c_char,
+) -> AgeResult {
+    if public_key.is_null() {
+        return AgeResult::InvalidInput;
+    }
+
+    let private_str = match unsafe { cstr_to_str(private_key) } {
+        Ok(s) => s,
+        Err(e) => return e,
+    };
+
+    let identity = match age::x25519::Identity::from_str(private_str) {
+        Ok(i) => i,
+        Err(_) => return AgeResult::InvalidIdentity,
+    };
+
+    let public_str = identity.to_public().to_string();
+    let c_public = match string_to_cstr(public_str) {
+        Ok(s) => s,
+        Err(e) => return e,
+    };
+
+    unsafe {
+        *public_key = c_public;
+    }
+
+    AgeResult::Success
+}