Revert "Propagate the NBYTES constant from Int256 to SecKey"

This reverts commit 0073c153d2.

libraries/crypto/src/ecdsa.rs

@@ -22,8 +22,6 @@ use super::{Hash256, HashBlockSize64Bytes};
 use alloc::vec::Vec;
 use core::marker::PhantomData;
 
-pub use super::ec::int256::NBYTES;
-
 #[derive(Clone, PartialEq)]
 #[cfg_attr(feature = "derive_debug", derive(Debug))]
 pub struct SecKey {
@@ -142,7 +140,7 @@ impl SecKey {
         }
     }
 
-    pub fn from_bytes(bytes: &[u8; NBYTES]) -> Option<SecKey> {
+    pub fn from_bytes(bytes: &[u8; 32]) -> Option<SecKey> {
         let k = NonZeroExponentP256::from_int_checked(Int256::from_bin(bytes));
         // The branching here is fine because all this reveals is whether the key was invalid.
         if bool::from(k.is_none()) {
@@ -152,7 +150,7 @@ impl SecKey {
         Some(SecKey { k })
     }
 
-    pub fn to_bytes(&self, bytes: &mut [u8; NBYTES]) {
+    pub fn to_bytes(&self, bytes: &mut [u8; 32]) {
         self.k.to_int().to_bin(bytes);
     }
 }

src/ctap/storage.rs

@@ -62,7 +62,7 @@ const AAGUID: usize = 7;
 const NUM_TAGS: usize = 8;
 
 const MAX_PIN_RETRIES: u8 = 6;
-const ATTESTATION_PRIVATE_KEY_LENGTH: usize = crypto::ecdsa::NBYTES;
+const ATTESTATION_PRIVATE_KEY_LENGTH: usize = 32;
 const AAGUID_LENGTH: usize = 16;
 
 #[derive(PartialEq, Eq, PartialOrd, Ord)]