Merge pull request #2003 from AdmiralGT/geoffthomas/crl-extensions

Add support for CRL extensions and the Authority Information Access extension

Author: Skepfyr

openssl/src/x509/mod.rs

@@ -1746,6 +1746,17 @@ unsafe impl ExtensionType for CertificateIssuer {
     type Output = Stack<GeneralName>;
 }
 
+/// The CRL extension identifying how to access information and services for the issuer of the CRL
+pub enum AuthorityInformationAccess {}
+
+// SAFETY: AuthorityInformationAccess is defined to be a stack of AccessDescription in the RFC
+// and in OpenSSL.
+unsafe impl ExtensionType for AuthorityInformationAccess {
+    const NID: Nid = Nid::from_raw(ffi::NID_info_access);
+
+    type Output = Stack<AccessDescription>;
+}
+
 foreign_type_and_impl_send_sync! {
     type CType = ffi::X509_CRL;
     fn drop = ffi::X509_CRL_free;
@@ -1915,6 +1926,36 @@ impl X509CrlRef {
     {
         unsafe { cvt_n(ffi::X509_CRL_verify(self.as_ptr(), key.as_ptr())).map(|n| n != 0) }
     }
+
+    /// Get the criticality and value of an extension.
+    ///
+    /// This returns None if the extension is not present or occurs multiple times.
+    #[corresponds(X509_CRL_get_ext_d2i)]
+    pub fn extension<T: ExtensionType>(&self) -> Result<Option<(bool, T::Output)>, ErrorStack> {
+        let mut critical = -1;
+        let out = unsafe {
+            // SAFETY: self.as_ptr() is a valid pointer to an X509_CRL.
+            let ext = ffi::X509_CRL_get_ext_d2i(
+                self.as_ptr(),
+                T::NID.as_raw(),
+                &mut critical as *mut _,
+                ptr::null_mut(),
+            );
+            // SAFETY: Extensions's contract promises that the type returned by
+            // OpenSSL here is T::Output.
+            T::Output::from_ptr_opt(ext as *mut _)
+        };
+        match (critical, out) {
+            (0, Some(out)) => Ok(Some((false, out))),
+            (1, Some(out)) => Ok(Some((true, out))),
+            // -1 means the extension wasn't found, -2 means multiple were found.
+            (-1 | -2, _) => Ok(None),
+            // A critical value of 0 or 1 suggests success, but a null pointer
+            // was returned so something went wrong.
+            (0 | 1, None) => Err(ErrorStack::get()),
+            (c_int::MIN..=-2 | 2.., _) => panic!("OpenSSL should only return -2, -1, 0, or 1 for an extension's criticality but it returned {}", critical),
+        }
+    }
 }
 
 /// The result of peer certificate verification.

openssl/src/x509/tests.rs

@@ -34,7 +34,7 @@ use hex::{self, FromHex};
 #[cfg(any(ossl102, libressl261))]
 use libc::time_t;
 
-use super::{CertificateIssuer, ReasonCode};
+use super::{AuthorityInformationAccess, CertificateIssuer, ReasonCode};
 
 fn pkey() -> PKey<Private> {
     let rsa = Rsa::generate(2048).unwrap();
@@ -701,6 +701,24 @@ fn test_crl_entry_extensions() {
     let crl = include_bytes!("../../test/entry_extensions.crl");
     let crl = X509Crl::from_pem(crl).unwrap();
 
+    let (critical, access_info) = crl
+        .extension::<AuthorityInformationAccess>()
+        .unwrap()
+        .expect("Authority Information Access extension should be present");
+    assert!(
+        !critical,
+        "Authority Information Access extension is not critical"
+    );
+    assert_eq!(
+        access_info.len(),
+        1,
+        "Authority Information Access should have one entry"
+    );
+    assert_eq!(access_info[0].method().to_string(), "CA Issuers");
+    assert_eq!(
+        access_info[0].location().uri(),
+        Some("http://www.example.com/ca.crt")
+    );
     let revoked_certs = crl.get_revoked().unwrap();
     let entry = &revoked_certs[0];
 

openssl/test/entry_extensions.crl

@@ -1,10 +1,11 @@
 -----BEGIN X509 CRL-----
-MIIBXDCCAQICAQEwCgYIKoZIzj0EAwIwETEPMA0GA1UEAwwGQ1JMIENBFw0yMzAz
-MjgwOTQ5MThaFw0yMzA0MDQwOTUwMDdaMIGAMH4CFE+Y95/1pOqa6c9fUEJ8c04k
-xu2PFw0yMzAzMjgwOTQ3MzNaMFcwLwYDVR0dAQH/BCUwI6QhMB8xCzAJBgNVBAYT
-AkdCMRAwDgYDVQQDDAdUZXN0IENBMAoGA1UdFQQDCgEBMBgGA1UdGAQRGA8yMDIz
-MDMyODA5NDQ0MFqgPTA7MB8GA1UdIwQYMBaAFNX1GZ0RWuC+4gz1wuy5H32T2W+R
-MAoGA1UdFAQDAgEUMAwGA1UdHAQFMAOEAf8wCgYIKoZIzj0EAwIDSAAwRQIgbl7x
-W+WVAb+zlvKcJLmHVuC+gbqR4jqwGIHHgQl2J8kCIQCo/sAF5sDqy/cL+fbzBeUe
-YoY2h6lIkj9ENwU8ZCt03w==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 -----END X509 CRL-----