[bssl] Move ec_key module from rialto to libbssl

Bug: 301068421
Test: atest rialto_test
Change-Id: I04f3040f79f1af18b5c76546adcd6616aa052729
diff --git a/rialto/src/requests/ec_key.rs b/rialto/src/requests/ec_key.rs
deleted file mode 100644
index fa96023..0000000
--- a/rialto/src/requests/ec_key.rs
+++ /dev/null
@@ -1,210 +0,0 @@
-// Copyright 2023, The Android Open Source Project
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-//! Contains struct and functions that wraps the API related to EC_KEY in
-//! BoringSSL.
-
-use alloc::vec::Vec;
-use bssl_avf::{ApiName, CbbFixed, Error, Result};
-use bssl_ffi::{
-    BN_bn2bin_padded, BN_clear_free, BN_new, CBB_flush, CBB_len, EC_KEY_free, EC_KEY_generate_key,
-    EC_KEY_get0_group, EC_KEY_get0_public_key, EC_KEY_marshal_private_key,
-    EC_KEY_new_by_curve_name, EC_POINT_get_affine_coordinates, NID_X9_62_prime256v1, BIGNUM,
-    EC_GROUP, EC_KEY, EC_POINT,
-};
-use core::ptr::{self, NonNull};
-use core::result;
-use coset::{iana, CoseKey, CoseKeyBuilder};
-use zeroize::{Zeroize, ZeroizeOnDrop, Zeroizing};
-
-const P256_AFFINE_COORDINATE_SIZE: usize = 32;
-
-type Coordinate = [u8; P256_AFFINE_COORDINATE_SIZE];
-
-/// Wrapper of an `EC_KEY` object, representing a public or private EC key.
-pub struct EcKey(NonNull<EC_KEY>);
-
-impl Drop for EcKey {
-    fn drop(&mut self) {
-        // SAFETY: It is safe because the key has been allocated by BoringSSL and isn't
-        // used after this.
-        unsafe { EC_KEY_free(self.0.as_ptr()) }
-    }
-}
-
-impl EcKey {
-    /// Creates a new EC P-256 key pair.
-    pub fn new_p256() -> Result<Self> {
-        // SAFETY: The returned pointer is checked below.
-        let ec_key = unsafe {
-            EC_KEY_new_by_curve_name(NID_X9_62_prime256v1) // EC P-256 CURVE Nid
-        };
-        let mut ec_key = NonNull::new(ec_key)
-            .map(Self)
-            .ok_or(Error::CallFailed(ApiName::EC_KEY_new_by_curve_name))?;
-        ec_key.generate_key()?;
-        Ok(ec_key)
-    }
-
-    /// Generates a random, private key, calculates the corresponding public key and stores both
-    /// in the `EC_KEY`.
-    fn generate_key(&mut self) -> Result<()> {
-        // SAFETY: The non-null pointer is created with `EC_KEY_new_by_curve_name` and should
-        // point to a valid `EC_KEY`.
-        // The randomness is provided by `getentropy()` in `vmbase`.
-        let ret = unsafe { EC_KEY_generate_key(self.0.as_ptr()) };
-        check_int_result(ret, ApiName::EC_KEY_generate_key)
-    }
-
-    /// Returns the `CoseKey` for the public key.
-    pub fn cose_public_key(&self) -> Result<CoseKey> {
-        const ALGO: iana::Algorithm = iana::Algorithm::ES256;
-        const CURVE: iana::EllipticCurve = iana::EllipticCurve::P_256;
-
-        let (x, y) = self.public_key_coordinates()?;
-        let key =
-            CoseKeyBuilder::new_ec2_pub_key(CURVE, x.to_vec(), y.to_vec()).algorithm(ALGO).build();
-        Ok(key)
-    }
-
-    /// Returns the x and y coordinates of the public key.
-    fn public_key_coordinates(&self) -> Result<(Coordinate, Coordinate)> {
-        let ec_group = self.ec_group()?;
-        let ec_point = self.public_key_ec_point()?;
-        let mut x = BigNum::new()?;
-        let mut y = BigNum::new()?;
-        let ctx = ptr::null_mut();
-        // SAFETY: All the parameters are checked non-null and initialized when needed.
-        // The last parameter `ctx` is generated when needed inside the function.
-        let ret = unsafe {
-            EC_POINT_get_affine_coordinates(ec_group, ec_point, x.as_mut_ptr(), y.as_mut_ptr(), ctx)
-        };
-        check_int_result(ret, ApiName::EC_POINT_get_affine_coordinates)?;
-        Ok((x.try_into()?, y.try_into()?))
-    }
-
-    /// Returns a pointer to the public key point inside `EC_KEY`. The memory region pointed
-    /// by the pointer is owned by the `EC_KEY`.
-    fn public_key_ec_point(&self) -> Result<*const EC_POINT> {
-        let ec_point =
-           // SAFETY: It is safe since the key pair has been generated and stored in the
-           // `EC_KEY` pointer.
-           unsafe { EC_KEY_get0_public_key(self.0.as_ptr()) };
-        if ec_point.is_null() {
-            Err(Error::CallFailed(ApiName::EC_KEY_get0_public_key))
-        } else {
-            Ok(ec_point)
-        }
-    }
-
-    /// Returns a pointer to the `EC_GROUP` object inside `EC_KEY`. The memory region pointed
-    /// by the pointer is owned by the `EC_KEY`.
-    fn ec_group(&self) -> Result<*const EC_GROUP> {
-        let group =
-           // SAFETY: It is safe since the key pair has been generated and stored in the
-           // `EC_KEY` pointer.
-           unsafe { EC_KEY_get0_group(self.0.as_ptr()) };
-        if group.is_null() {
-            Err(Error::CallFailed(ApiName::EC_KEY_get0_group))
-        } else {
-            Ok(group)
-        }
-    }
-
-    /// Returns the DER-encoded ECPrivateKey structure described in RFC 5915 Section 3:
-    ///
-    /// https://datatracker.ietf.org/doc/html/rfc5915#section-3
-    pub fn private_key(&self) -> Result<ZVec> {
-        const CAPACITY: usize = 256;
-        let mut buf = Zeroizing::new([0u8; CAPACITY]);
-        let mut cbb = CbbFixed::new(buf.as_mut());
-        let enc_flags = 0;
-        let ret =
-            // SAFETY: The function only write bytes to the buffer managed by the valid `CBB`
-            // object, and the key has been allocated by BoringSSL.
-            unsafe { EC_KEY_marshal_private_key(cbb.as_mut(), self.0.as_ptr(), enc_flags) };
-
-        check_int_result(ret, ApiName::EC_KEY_marshal_private_key)?;
-        // SAFETY: This is safe because the CBB pointer is a valid pointer initialized with
-        // `CBB_init_fixed()`.
-        check_int_result(unsafe { CBB_flush(cbb.as_mut()) }, ApiName::CBB_flush)?;
-        // SAFETY: This is safe because the CBB pointer is initialized with `CBB_init_fixed()`,
-        // and it has been flushed, thus it has no active children.
-        let len = unsafe { CBB_len(cbb.as_ref()) };
-        Ok(buf.get(0..len).ok_or(Error::CallFailed(ApiName::CBB_len))?.to_vec().into())
-    }
-}
-
-/// A u8 vector that is zeroed when dropped.
-#[derive(Zeroize, ZeroizeOnDrop)]
-pub struct ZVec(Vec<u8>);
-
-impl ZVec {
-    /// Extracts a slice containing the entire vector.
-    pub fn as_slice(&self) -> &[u8] {
-        &self.0[..]
-    }
-}
-
-impl From<Vec<u8>> for ZVec {
-    fn from(v: Vec<u8>) -> Self {
-        Self(v)
-    }
-}
-
-struct BigNum(NonNull<BIGNUM>);
-
-impl Drop for BigNum {
-    fn drop(&mut self) {
-        // SAFETY: The pointer has been created with `BN_new`.
-        unsafe { BN_clear_free(self.as_mut_ptr()) }
-    }
-}
-
-impl BigNum {
-    fn new() -> Result<Self> {
-        // SAFETY: The returned pointer is checked below.
-        let bn = unsafe { BN_new() };
-        NonNull::new(bn).map(Self).ok_or(Error::CallFailed(ApiName::BN_new))
-    }
-
-    fn as_mut_ptr(&mut self) -> *mut BIGNUM {
-        self.0.as_ptr()
-    }
-}
-
-/// Converts the `BigNum` to a big-endian integer. The integer is padded with leading zeros up to
-/// size `N`. The conversion fails if `N` is smaller thanthe size of the integer.
-impl<const N: usize> TryFrom<BigNum> for [u8; N] {
-    type Error = Error;
-
-    fn try_from(bn: BigNum) -> result::Result<Self, Self::Error> {
-        let mut num = [0u8; N];
-        // SAFETY: The `BIGNUM` pointer has been created with `BN_new`.
-        let ret = unsafe { BN_bn2bin_padded(num.as_mut_ptr(), num.len(), bn.0.as_ptr()) };
-        check_int_result(ret, ApiName::BN_bn2bin_padded)?;
-        Ok(num)
-    }
-}
-
-fn check_int_result(ret: i32, api_name: ApiName) -> Result<()> {
-    if ret == 1 {
-        Ok(())
-    } else {
-        assert_eq!(ret, 0, "Unexpected return value {ret} for {api_name:?}");
-        Err(Error::CallFailed(api_name))
-    }
-}
-
-// TODO(b/301068421): Unit tests the EcKey.
diff --git a/rialto/src/requests/mod.rs b/rialto/src/requests/mod.rs
index 8162237..d9e6f37 100644
--- a/rialto/src/requests/mod.rs
+++ b/rialto/src/requests/mod.rs
@@ -15,7 +15,6 @@
 //! This module contains functions for the request processing.
 
 mod api;
-mod ec_key;
 mod pub_key;
 mod rkp;
 
diff --git a/rialto/src/requests/rkp.rs b/rialto/src/requests/rkp.rs
index bcddf67..6982337 100644
--- a/rialto/src/requests/rkp.rs
+++ b/rialto/src/requests/rkp.rs
@@ -15,11 +15,11 @@
 //! This module contains functions related to the attestation of the
 //! service VM via the RKP (Remote Key Provisioning) server.
 
-use super::ec_key::EcKey;
 use super::pub_key::{build_maced_public_key, validate_public_key};
 use alloc::string::String;
 use alloc::vec;
 use alloc::vec::Vec;
+use bssl_avf::EcKey;
 use ciborium::{cbor, value::Value};
 use core::result;
 use coset::{iana, AsCborValue, CoseSign1, CoseSign1Builder, HeaderBuilder};