tweak

RustCrypto · Feb 12, 2025 · 67d7440 · 67d7440
1 parent aa15367
commit 67d7440
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Showing 3 changed files with 29 additions and 14 deletions.
diff --git a/des/src/des.rs b/des/src/des.rs
@@ -53,13 +53,7 @@ impl KeyInit for Des {
 
     #[inline]
     fn weak_key_test(key: &Key<Self>) -> Result<(), WeakKeyError> {
-        let key = u64::from_ne_bytes(key.0);
-        let mut is_weak = 0u8;
-
-        for &weak_key in crate::consts::WEAK_KEYS {
-            is_weak |= u8::from(key == weak_key);
-        }
-
+        let is_weak = super::weak_key_test(&key.0);
         if is_weak == 0 {
             Ok(())
         } else {

diff --git a/des/src/lib.rs b/des/src/lib.rs
@@ -30,3 +30,16 @@ mod utils;
 
 pub use crate::des::Des;
 pub use crate::tdes::{TdesEde2, TdesEde3, TdesEee2, TdesEee3};
+
+/// Checks whether the key is weak.
+///
+/// Returns 1 if key is weak and 0 otherwise.
+fn weak_key_test(key: &[u8; 8]) -> u8 {
+    let key = u64::from_ne_bytes(*key);
+    let mut is_weak = 0u8;
+
+    for &weak_key in crate::consts::WEAK_KEYS {
+        is_weak |= u8::from(key == weak_key);
+    }
+    is_weak
+}
diff --git a/des/src/tdes.rs b/des/src/tdes.rs
@@ -15,13 +15,21 @@ use core::fmt;
 use cipher::zeroize::ZeroizeOnDrop;
 
 #[inline]
-fn weak_key_test<U: KeyInit>(key: &Key<U>) -> Result<(), WeakKeyError> {
+fn weak_key_test(key: &[u8]) -> Result<(), WeakKeyError> {
     let sub_key_size = <Des as KeySizeUser>::KeySize::USIZE;
     assert_eq!(key.len() % sub_key_size, 0);
+
+    let mut is_weak = 0u8;
     for des_key in key.chunks_exact(sub_key_size) {
-        Des::weak_key_test(des_key.try_into().unwrap())?;
+        let des_key = des_key.try_into().unwrap();
+        is_weak |= super::weak_key_test(des_key);
+    }
+
+    if is_weak == 0 {
+        Ok(())
+    } else {
+        Err(WeakKeyError)
     }
-    Ok(())
 }
 
 /// Triple DES (3DES) block cipher.
@@ -50,7 +58,7 @@ impl KeyInit for TdesEde3 {
 
     #[inline]
     fn weak_key_test(key: &Key<Self>) -> Result<(), WeakKeyError> {
-        weak_key_test::<Self>(key)
+        weak_key_test(key)
     }
 }
 
@@ -139,7 +147,7 @@ impl KeyInit for TdesEee3 {
 
     #[inline]
     fn weak_key_test(key: &Key<Self>) -> Result<(), WeakKeyError> {
-        weak_key_test::<Self>(key)
+        weak_key_test(key)
     }
 }
 
@@ -225,7 +233,7 @@ impl KeyInit for TdesEde2 {
 
     #[inline]
     fn weak_key_test(key: &Key<Self>) -> Result<(), WeakKeyError> {
-        weak_key_test::<Self>(key)
+        weak_key_test(key)
     }
 }
 
@@ -311,7 +319,7 @@ impl KeyInit for TdesEee2 {
 
     #[inline]
     fn weak_key_test(key: &Key<Self>) -> Result<(), WeakKeyError> {
-        weak_key_test::<Self>(key)
+        weak_key_test(key)
     }
 }