From 687f0d26c4d3199179bb0b11485992e004038dba Mon Sep 17 00:00:00 2001
From: Michael Rossberg <michael.rossberg@tu-ilmenau.de>
Date: Mon, 15 Feb 2021 11:47:07 +0100
Subject: Add ec point validation functions

---
 openssl-sys/src/ec.rs |  8 ++++++++
 openssl/src/ec.rs     | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 57 insertions(+)

diff --git a/openssl-sys/src/ec.rs b/openssl-sys/src/ec.rs
index 98e233fb..82772fe8 100644
--- a/openssl-sys/src/ec.rs
+++ b/openssl-sys/src/ec.rs
@@ -81,6 +81,14 @@ extern "C" {
 
     pub fn EC_GROUP_new_by_curve_name(nid: c_int) -> *mut EC_GROUP;
 
+    pub fn EC_POINT_is_at_infinity(group: *const EC_GROUP, point: *const EC_POINT) -> c_int;
+
+    pub fn EC_POINT_is_on_curve(
+        group: *const EC_GROUP,
+        point: *const EC_POINT,
+        ctx: *mut BN_CTX,
+    ) -> c_int;
+
     pub fn EC_POINT_new(group: *const EC_GROUP) -> *mut EC_POINT;
 
     pub fn EC_POINT_free(point: *mut EC_POINT);
diff --git a/openssl/src/ec.rs b/openssl/src/ec.rs
index efbc26f6..1e266a0b 100644
--- a/openssl/src/ec.rs
+++ b/openssl/src/ec.rs
@@ -527,6 +527,30 @@ impl EcPointRef {
             .map(|_| ())
         }
     }
+
+    /// Checks if point is infinity
+    pub fn is_infinity(&self, group: &EcGroupRef) -> Result<bool, ErrorStack> {
+        unsafe {
+            let res = cvt_n(ffi::EC_POINT_is_at_infinity(group.as_ptr(), self.as_ptr()))?;
+            Ok(res == 1)
+        }
+    }
+
+    /// Checks if point is on a given curve
+    pub fn is_on_curve(
+        &self,
+        group: &EcGroupRef,
+        ctx: &mut BigNumContextRef,
+    ) -> Result<bool, ErrorStack> {
+        unsafe {
+            let res = cvt_n(ffi::EC_POINT_is_on_curve(
+                group.as_ptr(),
+                self.as_ptr(),
+                ctx.as_ptr(),
+            ))?;
+            Ok(res == 1)
+        }
+    }
 }
 
 impl EcPoint {
@@ -1074,4 +1098,29 @@ mod test {
         assert_eq!(xbn2, xbn);
         assert_eq!(ybn2, ybn);
     }
+
+    #[test]
+    fn is_infinity() {
+        let group = EcGroup::from_curve_name(Nid::X9_62_PRIME256V1).unwrap();
+        let mut ctx = BigNumContext::new().unwrap();
+        let g = group.generator();
+        assert_eq!(g.is_infinity(&group).unwrap(), false);
+
+        let mut order = BigNum::new().unwrap();
+        group.order(&mut order, &mut ctx).unwrap();
+        let mut inf = EcPoint::new(&group).unwrap();
+        inf.mul_generator(&group, &order, &ctx).unwrap();
+        assert_eq!(inf.is_infinity(&group).unwrap(), true);
+    }
+
+    #[test]
+    fn is_on_curve() {
+        let group = EcGroup::from_curve_name(Nid::X9_62_PRIME256V1).unwrap();
+        let mut ctx = BigNumContext::new().unwrap();
+        let g = group.generator();
+        assert_eq!(g.is_on_curve(&group, &mut ctx).unwrap(), true);
+
+        let group2 = EcGroup::from_curve_name(Nid::X9_62_PRIME239V3).unwrap();
+        assert_eq!(g.is_on_curve(&group2, &mut ctx).unwrap(), false);
+    }
 }
-- 
cgit v1.2.3


From 53a220bee6d19d3c70f6a60606eea353ad47e72a Mon Sep 17 00:00:00 2001
From: Michael Rossberg <michael.rossberg@tu-ilmenau.de>
Date: Mon, 15 Feb 2021 15:34:10 +0100
Subject: fix sfackler's comments

---
 openssl/src/ec.rs | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/openssl/src/ec.rs b/openssl/src/ec.rs
index 1e266a0b..32751cd2 100644
--- a/openssl/src/ec.rs
+++ b/openssl/src/ec.rs
@@ -529,14 +529,22 @@ impl EcPointRef {
     }
 
     /// Checks if point is infinity
-    pub fn is_infinity(&self, group: &EcGroupRef) -> Result<bool, ErrorStack> {
+    ///
+    /// OpenSSL documentation at [`EC_POINT_is_at_infinity`]
+    ///
+    /// [`EC_POINT_is_at_infinity`]: https://www.openssl.org/docs/man1.1.0/man3/EC_POINT_is_at_infinity.html
+    pub fn is_infinity(&self, group: &EcGroupRef) -> bool {
         unsafe {
-            let res = cvt_n(ffi::EC_POINT_is_at_infinity(group.as_ptr(), self.as_ptr()))?;
-            Ok(res == 1)
+            let res = ffi::EC_POINT_is_at_infinity(group.as_ptr(), self.as_ptr());
+            res == 1
         }
     }
 
     /// Checks if point is on a given curve
+    ///
+    /// OpenSSL documentation at [`EC_POINT_is_on_curve`]
+    ///
+    /// [`EC_POINT_is_on_curve`]: https://www.openssl.org/docs/man1.1.0/man3/EC_POINT_is_on_curve.html
     pub fn is_on_curve(
         &self,
         group: &EcGroupRef,
@@ -1104,13 +1112,13 @@ mod test {
         let group = EcGroup::from_curve_name(Nid::X9_62_PRIME256V1).unwrap();
         let mut ctx = BigNumContext::new().unwrap();
         let g = group.generator();
-        assert_eq!(g.is_infinity(&group).unwrap(), false);
+        assert_eq!(g.is_infinity(&group), false);
 
         let mut order = BigNum::new().unwrap();
         group.order(&mut order, &mut ctx).unwrap();
         let mut inf = EcPoint::new(&group).unwrap();
         inf.mul_generator(&group, &order, &ctx).unwrap();
-        assert_eq!(inf.is_infinity(&group).unwrap(), true);
+        assert_eq!(inf.is_infinity(&group), true);
     }
 
     #[test]
-- 
cgit v1.2.3