add other name support #1915

huettner94 · 2023-05-01T19:25:47Z

the issue with other name SANs is that they can contain arbitary data. As we can no longer use the old method for other_name for security reasons the easiest way now is to do individual implementations per datatype.

We start with strings for now, but it should be quite easy to expand upon that.

Closes: #1911

huettner94 · 2023-05-01T19:26:16Z

note: i did not test with boringssl i hope the ci does that

alex

Thanks for diving into this.

alex · 2023-05-01T21:40:36Z

openssl/src/x509/extension.rs

    pub fn other_name(&mut self, _other_name: &str) -> &mut SubjectAlternativeName {
        unimplemented!(
            "This has not yet been adapted for the new internals. File a bug if you need this."
        );
    }

+    /// Sets the `otherName` flag to a ia5string value.
+    pub fn other_name_string(&mut self, oid: &str, content: &str) -> &mut SubjectAlternativeName {


I think we want to use more precise types here: oid should be an Asn1ObjectIdentifier type, and contents should be &[u8] since it's DER.

I understand that idea, but i would also propose to support a more "userfriendly" way of doing things.

When the user can add arbitrary data as &[u8] it is not that easy to use that function anymore (and we need to define it as unsafe, since openssl has certain assumptions about the data).

If i know that field is a IA5STRING, then it would be ideal from my perspective if this library cares about the needed unsafe magic and i can just use the "easy" methods.

Would it be ok for you to add two versions? One that allows arbitrary (but unsafe) data, and one that is restricted to Strings?

IMO limiting to strings doesn't very much sense, OtherName is a very general purpose specification, and we should have an API that's similarly broad. Why do you think unsafe would be required?

thats why i would allow both. To get the combination of ease of use and all the features you might need.

I see unsafe as required as the data would then be passed to GENERAL_NAME_set0_othername. In there the openssl lib expects (if i understood it correctly) certain data formats (e.g. during deserialization). At least the last parameter must be a ASN1_TYPE as otherwise you will get a SegmentationFault (which is a clear sign to me that we need unsafe here, or guarantee that we do not need it like in the string case)

If the public API takes &[u8], a sequence of DER bytes, then it will be the responsibility of rust-openssl to have the unsafe code to turn that into an ASN1_TYPE, we can do that with d2i_ASN1_TYPE.

Thanks for the clarification.

I have now added other_name2 that will take a provided &[u8] and try to convert it to an ASN1_TYPE.

For ease of use i have adapted the other_name_ia5string method, but if you want to get rid of it that is also fine for me.

alex · 2023-05-01T21:41:21Z

openssl/src/x509/mod.rs

+            let s = cvt_p(ffi::ASN1_STRING_type_new(Asn1Type::IA5STRING.as_raw()))?;
+            ffi::ASN1_STRING_set(s, value.as_ptr().cast(), value.len().try_into().unwrap());


This isn't right, the value of an OtherName is not necessarily an IA5String, we need to handle arbitrary DER TLVs in the value.

alex

Getting close! Can you please add a test case or two to this.

alex · 2023-05-04T21:31:20Z

openssl/src/x509/extension.rs

+    ) -> Result<&mut SubjectAlternativeName, ErrorStack> {
+        let typ: *mut ASN1_TYPE;
+        unsafe {
+            ffi::init();
+
+            typ = cvt_p(ffi::d2i_ASN1_TYPE(
+                ptr::null_mut(),
+                &mut content.as_ptr().cast(),
+                content.len().try_into().unwrap(),
+            ))?;
+        }
+        self.items
+            .push(RustGeneralName::OtherName(oid.to_string(), typ));
+        Ok(self)
+    }


Would like @sfackler's take on this, specifically whether we should have this return a Result, or if it should be consistent with the other ones and just return &mut SAN and then do the error handling lazily.

alex · 2023-05-04T21:31:37Z

openssl/src/x509/extension.rs

+    /// If you want to add just a ia5string use `other_name_ia5string`
+    pub fn other_name2(
+        &mut self,
+        oid: &str,


Should take https://docs.rs/openssl/latest/openssl/asn1/struct.Asn1Object.html

alex · 2023-05-04T21:32:29Z

openssl/src/x509/extension.rs

+    /// Sets the `otherName` flag for ia5strings.
+    pub fn other_name_ia5string(
+        &mut self,
+        oid: &str,
+        content: &str,
+    ) -> &mut SubjectAlternativeName {


I'd prefer not to expose this -- the right way to do this is a separate, orthogonal API that makes it easy to DER serialize a https://docs.rs/openssl/latest/openssl/asn1/struct.Asn1String.html

done, added that api in a separate commit

alex · 2023-05-04T21:34:16Z

openssl/src/x509/mod.rs

+            let gn = cvt_p(ffi::GENERAL_NAME_new())?;
+            (*gn).type_ = ffi::GEN_OTHERNAME;
+
+            ffi::GENERAL_NAME_set0_othername(gn, oid.as_ptr().cast(), value);


This can technically fail and we should handle that.

huettner94 · 2023-05-09T20:12:22Z

i will add tests soon(tm)

alex

A few small comments, this is very close. Thanks for your work.

alex · 2023-05-09T22:27:43Z

openssl/src/x509/extension.rs

+        &mut self,
+        oid: Asn1Object,
+        content: &[u8],
+    ) -> Result<&mut SubjectAlternativeName, ErrorStack> {


@sfackler do you have an opinion on this returning a Result, vs. returning &mut SAN and doing the fallible ops in build?

Given that we're deferring the other fallible work to build currently, I'd have this do the same I think.

Ok, so in that case this should just return the builder, and we can conver to ASN1_TYPE in build and I think that will fix the other soundness problem

alex · 2023-05-09T22:28:02Z

openssl/src/x509/mod.rs

+            cvt(ffi::GENERAL_NAME_set0_othername(
+                gn,
+                oid.as_ptr().cast(),
+                value,
+            ))?;


If this fails then gn is leaked.

alex · 2023-05-09T22:28:37Z

openssl/src/asn1.rs

+impl Asn1String {
+    /// Converts a `&str` to an `Asn1String`.
+    pub fn from_str(data: &str) -> Result<Self, ErrorStack> {
+        unsafe {
+            let s = cvt_p(ffi::ASN1_STRING_type_new(Asn1Type::IA5STRING.as_raw()))?;
+            ffi::ASN1_STRING_set(s, data.as_ptr().cast(), data.len().try_into().unwrap());
+            Ok(Self::from_ptr(s))
+        }
+    }
+
+    /// Converts the Asn1String to the ASN.1 representation with a IA5String tag
+    pub fn as_asn1type_der(&self) -> Result<Vec<u8>, ErrorStack> {
+        unsafe {
+            let typ = cvt_p(ffi::ASN1_TYPE_new()).unwrap();
+            ffi::ASN1_TYPE_set(typ, ffi::V_ASN1_IA5STRING, self.0.cast());
+
+            let len = cvt(ffi::i2d_ASN1_TYPE(typ, ptr::null_mut()))?;
+            let mut buf = vec![0; len as usize];
+            crate::cvt(ffi::i2d_ASN1_TYPE(typ, &mut buf.as_mut_ptr()))?;
+            Ok(buf)
+        }
+    }
+}
+


Can we do this in a separate PR? It should be orthagonal to the rest of this.

sure, will open one soon

alex · 2023-05-09T22:29:40Z

openssl/src/asn1.rs

@@ -705,6 +729,12 @@ impl Asn1Object {
    }
 }

+impl Clone for Asn1Object {
+    fn clone(&self) -> Self {
+        unsafe { Asn1Object::from_ptr(cvt_p(ffi::OBJ_dup(self.as_ptr())).unwrap()) }


Instead of this you can do clone = OBJ_dup; in the foreign_type_and_impl_send_sync macro.

thanks, done

alex · 2023-05-09T22:30:01Z

openssl/src/x509/extension.rs

+    /// Not currently actually supported, always panics. Please use other_name2 or other_name_ia5string
+    #[deprecated = "other_name is deprecated and always panics. Please use other_name2 or other_name_ia5string."]


Suggested change

/// Not currently actually supported, always panics. Please use other_name2 or other_name_ia5string

#[deprecated = "other_name is deprecated and always panics. Please use other_name2 or other_name_ia5string."]

/// Not currently actually supported, always panics. Please use other_name2

#[deprecated = "other_name is deprecated and always panics. Please use other_name2."]

thanks fixed

alex · 2023-05-09T22:30:09Z

openssl/src/x509/extension.rs

    pub fn other_name(&mut self, _other_name: &str) -> &mut SubjectAlternativeName {
        unimplemented!(
-            "This has not yet been adapted for the new internals. File a bug if you need this."
+            "This has not yet been adapted for the new internals. Use other_name2 or other_name_ia5string."


Suggested change

"This has not yet been adapted for the new internals. Use other_name2 or other_name_ia5string."

"This has not yet been adapted for the new internals. Use other_name2."

thanks fixed

huettner94 · 2023-05-17T21:00:45Z

i added a small testcase. is that sufficient or would you like a larger one

depends on sfackler/rust-openssl#1915 and sfackler/rust-openssl#1928

alex · 2023-05-23T20:35:31Z

openssl/src/x509/extension.rs

@@ -506,12 +511,34 @@ impl SubjectAlternativeName {

    /// Sets the `otherName` flag.
    ///
-    /// Not currently actually supported, always panics.
-    #[deprecated = "other_name is deprecated and always panics. Please file a bug if you have a use case for this."]
+    /// Not currently actually supported, always panics. Please use other_name2 or other_name_ia5string


Suggested change

/// Not currently actually supported, always panics. Please use other_name2 or other_name_ia5string

/// Not currently actually supported, always panics. Please use other_name2

thanks fixed

alex · 2023-05-23T20:37:50Z

openssl/src/x509/mod.rs

+            if let Err(e) = cvt(ffi::GENERAL_NAME_set0_othername(
+                gn,
+                oid.as_ptr().cast(),
+                value,
+            )) {


Unfortunately this isn't sound -- because build takes &self you can call it multiple times, in which case the value ptr will be reused.

handled as already commented somewhere else

the issue with other name SANs is that they can contain arbitary data. As we can no longer use the old method for other_name for security reasons we now add `other_name2` as an alternative.

huettner94 force-pushed the feat_other_name branch 2 times, most recently from 58a5e90 to 8f99f0f Compare May 1, 2023 20:09

alex reviewed May 1, 2023

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huettner94 force-pushed the feat_other_name branch from 8f99f0f to 347545d Compare May 4, 2023 18:51

alex reviewed May 4, 2023

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huettner94 force-pushed the feat_other_name branch from 347545d to 77c0850 Compare May 9, 2023 20:10

alex reviewed May 9, 2023

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huettner94 force-pushed the feat_other_name branch from 77c0850 to e1154cd Compare May 17, 2023 21:00

huettner94 mentioned this pull request May 17, 2023

simplify converting asn1string #1928

Open

huettner94 force-pushed the feat_other_name branch from e1154cd to 56f9813 Compare May 17, 2023 21:12

huettner94 added a commit to huettner94/dtn that referenced this pull request May 17, 2023

Fix othername generation

b6e8dcd

depends on sfackler/rust-openssl#1915 and sfackler/rust-openssl#1928

huettner94 force-pushed the feat_other_name branch 2 times, most recently from 8ae9cd1 to b5a6abc Compare May 17, 2023 21:25

alex reviewed May 23, 2023

View reviewed changes

huettner94 force-pushed the feat_other_name branch from b5a6abc to 3c28987 Compare May 25, 2023 18:46

add other name support

56e94e3

the issue with other name SANs is that they can contain arbitary data. As we can no longer use the old method for other_name for security reasons we now add `other_name2` as an alternative.

huettner94 force-pushed the feat_other_name branch from 3c28987 to 56e94e3 Compare May 25, 2023 18:50

alex merged commit 14b6ad5 into sfackler:master May 26, 2023

huettner94 deleted the feat_other_name branch May 28, 2023 20:09

beaufour mentioned this pull request Jun 22, 2023

Bump openssl from 0.10.48 to 0.10.55 beaufour/fios-stats#11

Merged

renovate bot mentioned this pull request Sep 15, 2023

chore(deps): update all non-major dependencies lyonkit/lyonkit-api#222

Open

1 task

		let s = cvt_p(ffi::ASN1_STRING_type_new(Asn1Type::IA5STRING.as_raw()))?;
		ffi::ASN1_STRING_set(s, value.as_ptr().cast(), value.len().try_into().unwrap());

		/// Not currently actually supported, always panics. Please use other_name2 or other_name_ia5string
		#[deprecated = "other_name is deprecated and always panics. Please use other_name2 or other_name_ia5string."]

	"This has not yet been adapted for the new internals. Use other_name2 or other_name_ia5string."
	"This has not yet been adapted for the new internals. Use other_name2."

add other name support #1915

add other name support #1915

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huettner94 commented May 1, 2023

huettner94 commented May 1, 2023

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huettner94 commented May 9, 2023

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huettner94 commented May 17, 2023

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