pkey_ctx: add dsa params generation test

boring doesn't support DSA paramgen in a pkey ctx since
google/boringssl@2e295b9

Author: huwcbjones

openssl/src/pkey_ctx.rs

@@ -958,6 +958,19 @@ mod test {
         ctx.keygen().unwrap();
     }
 
+    #[test]
+    #[cfg(not(boringssl))]
+    fn dsa_paramgen() {
+        let mut ctx = PkeyCtx::new_id(Id::DSA).unwrap();
+        ctx.paramgen_init().unwrap();
+        ctx.set_dsa_paramgen_bits(2048).unwrap();
+        let params = ctx.paramgen().unwrap();
+        #[cfg(not(awslc))]
+        assert_eq!(params.size(), 64);
+        #[cfg(awslc)]
+        assert_eq!(params.size(), 72);
+    }
+
     #[test]
     #[cfg(any(ossl110, boringssl, libressl360, awslc))]
     fn hkdf() {