diff --git a/libs/bssl/error/src/lib.rs b/libs/bssl/error/src/lib.rs
index 3766c41..88929af 100644
--- a/libs/bssl/error/src/lib.rs
+++ b/libs/bssl/error/src/lib.rs
@@ -56,11 +56,13 @@
     BN_bn2bin_padded,
     CBB_flush,
     CBB_len,
+    EC_GROUP_new_by_curve_name,
     EC_KEY_check_key,
     EC_KEY_generate_key,
     EC_KEY_get0_group,
     EC_KEY_get0_public_key,
     EC_KEY_marshal_private_key,
+    EC_KEY_parse_private_key,
     EC_KEY_new_by_curve_name,
     EC_POINT_get_affine_coordinates,
     EVP_AEAD_CTX_new,
diff --git a/libs/bssl/src/cbs.rs b/libs/bssl/src/cbs.rs
new file mode 100644
index 0000000..9718903
--- /dev/null
+++ b/libs/bssl/src/cbs.rs
@@ -0,0 +1,55 @@
+// 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.
+
+//! Helpers for using BoringSSL CBS (crypto byte string) objects.
+
+use bssl_ffi::{CBS_init, CBS};
+use core::marker::PhantomData;
+use core::mem::MaybeUninit;
+
+/// CRYPTO ByteString.
+///
+/// Wraps a `CBS` that references an existing fixed-sized buffer; no memory is allocated, but the
+/// buffer cannot grow.
+pub struct Cbs<'a> {
+    cbs: CBS,
+    /// The CBS contains a mutable reference to the buffer, disguised as a pointer.
+    /// Make sure the borrow checker knows that.
+    _buffer: PhantomData<&'a [u8]>,
+}
+
+impl<'a> Cbs<'a> {
+    /// Creates a new CBS that points to the given buffer.
+    pub fn new(buffer: &'a [u8]) -> Self {
+        let mut cbs = MaybeUninit::uninit();
+        // SAFETY: `CBS_init()` only sets `cbs` to point to `buffer`. It doesn't take ownership
+        // of data.
+        unsafe { CBS_init(cbs.as_mut_ptr(), buffer.as_ptr(), buffer.len()) };
+        // SAFETY: `cbs` has just been initialized by `CBS_init()`.
+        let cbs = unsafe { cbs.assume_init() };
+        Self { cbs, _buffer: PhantomData }
+    }
+}
+
+impl<'a> AsRef<CBS> for Cbs<'a> {
+    fn as_ref(&self) -> &CBS {
+        &self.cbs
+    }
+}
+
+impl<'a> AsMut<CBS> for Cbs<'a> {
+    fn as_mut(&mut self) -> &mut CBS {
+        &mut self.cbs
+    }
+}
diff --git a/libs/bssl/src/ec_key.rs b/libs/bssl/src/ec_key.rs
index 7038e21..4c1ba5c 100644
--- a/libs/bssl/src/ec_key.rs
+++ b/libs/bssl/src/ec_key.rs
@@ -16,14 +16,15 @@
 //! BoringSSL.
 
 use crate::cbb::CbbFixed;
+use crate::cbs::Cbs;
 use crate::util::{check_int_result, to_call_failed_error};
 use alloc::vec::Vec;
 use bssl_avf_error::{ApiName, 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,
+    BN_bn2bin_padded, BN_clear_free, BN_new, CBB_flush, CBB_len, EC_GROUP_new_by_curve_name,
+    EC_KEY_check_key, 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_KEY_parse_private_key,
+    EC_POINT_get_affine_coordinates, NID_X9_62_prime256v1, BIGNUM, EC_GROUP, EC_KEY, EC_POINT,
 };
 use core::ptr::{self, NonNull};
 use core::result;
@@ -59,6 +60,16 @@
         Ok(ec_key)
     }
 
+    /// Performs several checks on the key. See BoringSSL doc for more details:
+    ///
+    /// https://commondatastorage.googleapis.com/chromium-boringssl-docs/ec_key.h.html#EC_KEY_check_key
+    pub fn check_key(&self) -> Result<()> {
+        // SAFETY: This function only reads the `EC_KEY` pointer, the non-null check is performed
+        // within the function.
+        let ret = unsafe { EC_KEY_check_key(self.0.as_ptr()) };
+        check_int_result(ret, ApiName::EC_KEY_check_key)
+    }
+
     /// Generates a random, private key, calculates the corresponding public key and stores both
     /// in the `EC_KEY`.
     fn generate_key(&mut self) -> Result<()> {
@@ -124,10 +135,34 @@
         }
     }
 
+    /// Constructs an `EcKey` instance from the provided DER-encoded ECPrivateKey slice.
+    ///
+    /// Currently, only the EC P-256 curve is supported.
+    pub fn from_ec_private_key(der_encoded_ec_private_key: &[u8]) -> Result<Self> {
+        // SAFETY: This function only returns a pointer to a static object, and the
+        // return is checked below.
+        let ec_group = unsafe {
+            EC_GROUP_new_by_curve_name(NID_X9_62_prime256v1) // EC P-256 CURVE Nid
+        };
+        if ec_group.is_null() {
+            return Err(to_call_failed_error(ApiName::EC_GROUP_new_by_curve_name));
+        }
+        let mut cbs = Cbs::new(der_encoded_ec_private_key);
+        // SAFETY: The function only reads bytes from the buffer managed by the valid `CBS`
+        // object, and the returned EC_KEY is checked.
+        let ec_key = unsafe { EC_KEY_parse_private_key(cbs.as_mut(), ec_group) };
+
+        let ec_key = NonNull::new(ec_key)
+            .map(Self)
+            .ok_or(to_call_failed_error(ApiName::EC_KEY_parse_private_key))?;
+        ec_key.check_key()?;
+        Ok(ec_key)
+    }
+
     /// 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> {
+    pub fn ec_private_key(&self) -> Result<ZVec> {
         const CAPACITY: usize = 256;
         let mut buf = Zeroizing::new([0u8; CAPACITY]);
         let mut cbb = CbbFixed::new(buf.as_mut());
diff --git a/libs/bssl/src/lib.rs b/libs/bssl/src/lib.rs
index 709e8ad..de81368 100644
--- a/libs/bssl/src/lib.rs
+++ b/libs/bssl/src/lib.rs
@@ -20,6 +20,7 @@
 
 mod aead;
 mod cbb;
+mod cbs;
 mod digest;
 mod ec_key;
 mod err;
@@ -32,6 +33,7 @@
 
 pub use aead::{Aead, AeadContext, AES_GCM_NONCE_LENGTH};
 pub use cbb::CbbFixed;
+pub use cbs::Cbs;
 pub use digest::Digester;
 pub use ec_key::{EcKey, ZVec};
 pub use hkdf::hkdf;
diff --git a/libs/bssl/tests/eckey_test.rs b/libs/bssl/tests/eckey_test.rs
new file mode 100644
index 0000000..a013fba
--- /dev/null
+++ b/libs/bssl/tests/eckey_test.rs
@@ -0,0 +1,25 @@
+// 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.
+
+use bssl_avf::{EcKey, Result};
+
+#[test]
+fn ec_private_key_serialization() -> Result<()> {
+    let ec_key = EcKey::new_p256()?;
+    let der_encoded_ec_private_key = ec_key.ec_private_key()?;
+    let deserialized_ec_key = EcKey::from_ec_private_key(der_encoded_ec_private_key.as_slice())?;
+
+    assert_eq!(ec_key.cose_public_key()?, deserialized_ec_key.cose_public_key()?);
+    Ok(())
+}
diff --git a/libs/bssl/tests/tests.rs b/libs/bssl/tests/tests.rs
index 4c0b0b0..02666d8 100644
--- a/libs/bssl/tests/tests.rs
+++ b/libs/bssl/tests/tests.rs
@@ -15,5 +15,6 @@
 //! API tests of the crate `bssl_avf`.
 
 mod aead_test;
+mod eckey_test;
 mod hkdf_test;
 mod hmac_test;