feat(quote): add sig/pubkey crypto and some quote header types

Cargo.toml

@@ -28,6 +28,7 @@ rcrypto = ["rand", "rsa", "sha2", "num-integer", "num-traits"]
 x86_64 = { version = "^0.14.6", default-features = false }
 xsave = { version = "^2.0.0", default-features = false }
 openssl = { version = "^0.10.36", optional = true }
+der = { version = "0.6.0-pre.3", features = ["derive"], optional = false }
 bitflags = "^1.3.2"
 
 # Used by the rcrypto feature (see above).

README.md

@@ -19,5 +19,7 @@ How to use this crate partly depends on what you are trying to accomplish:
   3. If you are developing an enclave loader, you probably want the
      `parameters` and `page` modules. However, you may also want the
      `signature` module to load a signature.
+  4. If you are interested in quote parsing and validation, you probably
+     want the `quote` module.
 
 License: Apache-2.0

src/crypto/mod.rs

@@ -11,6 +11,8 @@ pub mod openssl;
 #[cfg(feature = "rcrypto")]
 pub mod rcrypto;
 
+use der::{asn1::UIntBytes, Encodable, Sequence};
+
 /// A fixed-size hash
 pub trait Digest: Sized {
     type Output: AsRef<[u8]>;
@@ -45,6 +47,58 @@ pub struct SigData {
     pub q2: [u8; 384],
 }
 
+/// EC KT-I Public Key, the x-coordinate followed by
+/// the y-coordinate (on the RFC 6090P-256 curve),
+/// 2 x 32 bytes.
+/// A.4, Table 7
+#[derive(Clone, Debug)]
+#[repr(C)]
+pub struct EcdsaPubKey {
+    pub x: [u8; 32],
+    pub y: [u8; 32],
+}
+
+/// ECDSA signature, the r component followed by the
+/// s component, 2 x 32 bytes.
+/// A.4, Table 6
+#[derive(Clone, Debug)]
+#[repr(C)]
+pub struct EcdsaP256Sig {
+    pub r: [u8; 32],
+    pub s: [u8; 32],
+}
+
+impl EcdsaP256Sig {
+    // The size of the buffer the DER encoded signature will occupy.
+    const DER_ENCODED_LEN: usize = 72;
+
+    /// Converts the concatenated signature to a DER signature.
+    ///
+    /// Returns the buffer containing the DER and its length.
+    pub fn to_der(&self) -> Result<([u8; Self::DER_ENCODED_LEN], usize), der::Error> {
+        /// ECDSA-Sig-Value ::= SEQUENCE {
+        ///    r INTEGER,
+        ///    s INTEGER
+        /// }
+        #[derive(Clone, Debug, Sequence)]
+        struct EcdsaSig<'a> {
+            r: UIntBytes<'a>,
+            s: UIntBytes<'a>,
+        }
+
+        let es = EcdsaSig {
+            r: UIntBytes::new(&self.r)?,
+            s: UIntBytes::new(&self.s)?,
+        };
+
+        let mut buffer = [0; Self::DER_ENCODED_LEN];
+        let mut encoder = der::Encoder::new(&mut buffer);
+        es.encode(&mut encoder)?;
+        let len = encoder.finish()?.len();
+        Ok((buffer, len))
+    }
+}
+
 #[cfg(test)]
 #[allow(dead_code)]
 fn selftest<K: PrivateKey, D: Digest<Output = [u8; 32]>>() {

src/lib.rs

@@ -14,6 +14,8 @@
 //!   3. If you are developing an enclave loader, you probably want the
 //!      `parameters` and `page` modules. However, you may also want the
 //!      `signature` module to load a signature.
+//!   4. If you are interested in quote parsing and validation, you probably
+//!      want the `quote` module.
 
 #![cfg_attr(not(test), no_std)]
 #![deny(clippy::exhaustive_enums)]
@@ -87,6 +89,7 @@ macro_rules! testaso {
 pub mod crypto;
 pub mod page;
 pub mod parameters;
+pub mod quote;
 pub mod signature;
 pub mod ssa;
 

src/quote/header.rs

@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: Apache-2.0
+
+/// The type of attestation key used to sign the Report.
+///
+/// ECDSA: <https://en.wikipedia.org/wiki/Elliptic_Curve_Digital_Signature_Algorithm>
+#[derive(Debug, Clone, Copy, Eq, PartialEq)]
+#[non_exhaustive]
+#[repr(u16)]
+pub enum KeyType {
+    /// ECDSA-256-with-P-256 curve
+    ES256 = 2,
+    /// ECDSA-384-with-P-384 curve
+    ES384 = 3,
+}
+
+/// The version of the quote.
+#[derive(Debug, Clone, Copy, Eq, PartialEq)]
+#[non_exhaustive]
+#[repr(u16)]
+pub enum QuoteVersion {
+    V3 = 3,
+}

src/quote/mod.rs

@@ -0,0 +1,3 @@
+// SPDX-License-Identifier: Apache-2.0
+
+pub mod header;