Add functions to X509Req to obtain public key and extensions

This allows for basic CSR signing.

openssl-sys/src/lib.rs

@@ -2741,8 +2741,10 @@ extern "C" {
     pub fn X509_REQ_set_version(req: *mut X509_REQ, version: c_long) -> c_int;
     pub fn X509_REQ_set_subject_name(req: *mut X509_REQ, name: *mut X509_NAME) -> c_int;
     pub fn X509_REQ_set_pubkey(req: *mut X509_REQ, pkey: *mut EVP_PKEY) -> c_int;
+    pub fn X509_REQ_get_pubkey(req: *mut X509_REQ) -> *mut EVP_PKEY;
     pub fn X509_REQ_add_extensions(req: *mut X509_REQ, exts: *mut stack_st_X509_EXTENSION)
         -> c_int;
+    pub fn X509_REQ_get_extensions(req: *mut X509_REQ) -> *mut stack_st_X509_EXTENSION;
     pub fn X509_REQ_sign(x: *mut X509_REQ, pkey: *mut EVP_PKEY, md: *const EVP_MD) -> c_int;
 
     #[cfg(not(ossl101))]

openssl/src/x509/mod.rs

@@ -1069,6 +1069,28 @@ impl X509ReqRef {
             X509NameRef::from_ptr(name)
         }
     }
+
+    /// Returns the public key of the certificate request.
+    ///
+    /// This corresponds to [`X509_REQ_get_pubkey"]
+    ///
+    /// [`X509_REQ_get_pubkey`]: https://www.openssl.org/docs/man1.1.0/crypto/X509_REQ_get_pubkey.html
+    pub fn public_key(&self) -> Result<PKey<Public>, ErrorStack> {
+        unsafe {
+            let key = cvt_p(ffi::X509_REQ_get_pubkey(self.as_ptr()))?;
+            Ok(PKey::from_ptr(key))
+        }
+    }
+
+    /// Returns the extensions of the certificate request.
+    ///
+    /// This corresponds to [`X509_REQ_get_extensions"]
+    pub fn extensions(&self) -> Result<Stack<X509Extension>, ErrorStack> {
+        unsafe {
+            let extensions = cvt_p(ffi::X509_REQ_get_extensions(self.as_ptr()))?;
+            Ok(Stack::from_ptr(extensions))
+        }
+    }
 }
 
 /// The result of peer certificate verification.

openssl/src/x509/tests.rs

@@ -234,6 +234,10 @@ fn x509_req_builder() {
     builder.add_extensions(&extensions).unwrap();
 
     builder.sign(&pkey, MessageDigest::sha256()).unwrap();
+
+    let req = builder.build();
+    assert!(req.public_key().unwrap().public_eq(&pkey));
+    assert_eq!(req.extensions().unwrap().len(), extensions.len());
 }
 
 #[test]