pkey_ctx: add ability to generate EC params & keys

openssl-sys/src/ec.rs

@@ -5,6 +5,20 @@ use super::*;
 
 pub const OPENSSL_EC_NAMED_CURVE: c_int = 1;
 
+cfg_if! {
+    if #[cfg(not(ossl300))] {
+        pub unsafe fn EVP_PKEY_CTX_set_ec_paramgen_curve_nid(ctx: *mut EVP_PKEY_CTX, nid: c_int) -> c_int {
+            EVP_PKEY_CTX_ctrl(
+                ctx,
+                EVP_PKEY_EC,
+                EVP_PKEY_OP_PARAMGEN|EVP_PKEY_OP_KEYGEN,
+                EVP_PKEY_CTRL_EC_PARAMGEN_CURVE_NID,
+                nid,
+                ptr::null_mut(),
+            )
+        }
+    }
+}
 #[cfg(ossl300)]
 pub unsafe fn EVP_EC_gen(curve: *const c_char) -> *mut EVP_PKEY {
     EVP_PKEY_Q_keygen(
@@ -14,3 +28,5 @@ pub unsafe fn EVP_EC_gen(curve: *const c_char) -> *mut EVP_PKEY {
         curve,
     )
 }
+
+pub const EVP_PKEY_CTRL_EC_PARAMGEN_CURVE_NID: c_int = EVP_PKEY_ALG_CTRL + 1;

openssl-sys/src/handwritten/ec.rs

@@ -1,6 +1,11 @@
 use super::super::*;
 use libc::*;
 
+#[cfg(ossl300)]
+extern "C" {
+    pub fn EVP_PKEY_CTX_set_ec_paramgen_curve_nid(ctx: *mut EVP_PKEY_CTX, nid: c_int) -> c_int;
+}
+
 #[repr(C)]
 #[derive(Copy, Clone)]
 pub enum point_conversion_form_t {

openssl/src/pkey_ctx.rs

@@ -68,6 +68,7 @@ let cmac_key = ctx.keygen().unwrap();
 use crate::cipher::CipherRef;
 use crate::error::ErrorStack;
 use crate::md::MdRef;
+use crate::nid::Nid;
 use crate::pkey::{HasPrivate, HasPublic, Id, PKey, PKeyRef, Params, Private};
 use crate::rsa::Padding;
 use crate::sign::RsaPssSaltlen;
@@ -463,6 +464,22 @@ impl<T> PkeyCtxRef<T> {
         Ok(())
     }
 
+    /// Sets the EC paramgen curve NID.
+    ///
+    /// This is only useful for EC keys.
+    #[corresponds(EVP_PKEY_CTX_set_ec_paramgen_curve_nid)]
+    #[inline]
+    pub fn set_ec_paramgen_curve_nid(&mut self, nid: Nid) -> Result<(), ErrorStack> {
+        unsafe {
+            cvt(ffi::EVP_PKEY_CTX_set_ec_paramgen_curve_nid(
+                self.as_ptr(),
+                nid.as_raw(),
+            ))?;
+        }
+
+        Ok(())
+    }
+
     /// Returns the RSA padding mode in use.
     ///
     /// This is only useful for RSA keys.
@@ -983,6 +1000,17 @@ mod test {
         assert_eq!(params.size(), size);
     }
 
+    #[test]
+    fn ec_keygen() {
+        let mut ctx = PkeyCtx::new_id(Id::EC).unwrap();
+        ctx.paramgen_init().unwrap();
+        ctx.set_ec_paramgen_curve_nid(Nid::X9_62_PRIME256V1)
+            .unwrap();
+        let params = ctx.paramgen().unwrap();
+
+        assert_eq!(params.size(), 72);
+    }
+
     #[test]
     #[cfg(any(ossl110, boringssl, libressl360, awslc))]
     fn hkdf() {