fix keypair repr on big-endian architectures

Author: kwantam

secp256k1-sys/src/lib.rs

@@ -462,12 +462,18 @@ impl KeyPair {
     /// [`zeroize`](https://docs.rs/zeroize) crate.
     #[inline]
     pub fn non_secure_erase(&mut self) {
-        // DUMMY is a valid key pair with secret key `[1u8; 32]`
-        const DUMMY: [c_uchar; 96] = [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 143, 7, 221, 213, 233, 245, 23, 156, 255, 25, 72, 96, 52, 24, 30, 215, 101, 5, 186, 170, 213, 62, 93, 153, 64, 100, 18, 123, 86, 197, 132, 27, 209, 232, 168, 105, 122, 212, 34, 81, 222, 57, 246, 167, 32, 129, 223, 223, 66, 171, 197, 66, 166, 214, 254, 7, 21, 84, 139, 88, 143, 175, 190, 112];
-        non_secure_erase_impl(&mut self.0, DUMMY);
+        non_secure_erase_impl(&mut self.0, DUMMY_KEYPAIR);
     }
 }
 
+// DUMMY_KEYPAIR is the internal repr of a valid key pair with secret key `[1u8; 32]`
+#[cfg(all(target_endian = "little"))]
+const DUMMY_KEYPAIR: [c_uchar; 96] = [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 143, 7, 221, 213, 233, 245, 23, 156, 255, 25, 72, 96, 52, 24, 30, 215, 101, 5, 186, 170, 213, 62, 93, 153, 64, 100, 18, 123, 86, 197, 132, 27, 209, 232, 168, 105, 122, 212, 34, 81, 222, 57, 246, 167, 32, 129, 223, 223, 66, 171, 197, 66, 166, 214, 254, 7, 21, 84, 139, 88, 143, 175, 190, 112];
+#[cfg(all(target_endian = "big", target_pointer_width = "32"))]
+const DUMMY_KEYPAIR: [c_uchar; 96] = [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 213, 221, 7, 143, 156, 23, 245, 233, 96, 72, 25, 255, 215, 30, 24, 52, 170, 186, 5, 101, 153, 93, 62, 213, 123, 18, 100, 64, 27, 132, 197, 86, 105, 168, 232, 209, 81, 34, 212, 122, 167, 246, 57, 222, 223, 223, 129, 32, 66, 197, 171, 66, 7, 254, 214, 166, 88, 139, 84, 21, 112, 190, 175, 143];
+#[cfg(all(target_endian = "big", target_pointer_width = "64"))]
+const DUMMY_KEYPAIR: [c_uchar; 96] = [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 156, 23, 245, 233, 213, 221, 7, 143, 215, 30, 24, 52, 96, 72, 25, 255, 153, 93, 62, 213, 170, 186, 5, 101, 27, 132, 197, 86, 123, 18, 100, 64, 81, 34, 212, 122, 105, 168, 232, 209, 223, 223, 129, 32, 167, 246, 57, 222, 7, 254, 214, 166, 66, 197, 171, 66, 112, 190, 175, 143, 88, 139, 84, 21];
+
 /// This function implements a best attempt at secure erasure using Rust intrinsics.
 /// The implementation is based on the approach used by the [`zeroize`](https://docs.rs/zeroize) crate.
 #[inline(always)]