Rust wrapper: zeroize aead keys on stack

Fixes F-11286.

Author: holtrop-wolfssl

wrapper/rust/wolfssl-wolfcrypt/src/aes.rs

@@ -526,7 +526,9 @@ impl KeyInit for Aes128Ccm {
     fn new(key: &aead::Key<Self>) -> Self {
         let mut k = [0u8; 16];
         k.copy_from_slice(key.as_ref());
-        Aes128Ccm { key: k }
+        let out = Aes128Ccm { key: k };
+        k.zeroize();
+        out
     }
 }
 
@@ -578,7 +580,9 @@ impl KeyInit for Aes192Ccm {
     fn new(key: &aead::Key<Self>) -> Self {
         let mut k = [0u8; 24];
         k.copy_from_slice(key.as_ref());
-        Aes192Ccm { key: k }
+        let out = Aes192Ccm { key: k };
+        k.zeroize();
+        out
     }
 }
 
@@ -630,7 +634,9 @@ impl KeyInit for Aes256Ccm {
     fn new(key: &aead::Key<Self>) -> Self {
         let mut k = [0u8; 32];
         k.copy_from_slice(key.as_ref());
-        Aes256Ccm { key: k }
+        let out = Aes256Ccm { key: k };
+        k.zeroize();
+        out
     }
 }
 
@@ -1742,7 +1748,9 @@ impl KeyInit for Aes128Gcm {
     fn new(key: &aead::Key<Self>) -> Self {
         let mut k = [0u8; 16];
         k.copy_from_slice(key.as_ref());
-        Aes128Gcm { key: k }
+        let out = Aes128Gcm { key: k };
+        k.zeroize();
+        out
     }
 }
 
@@ -1794,7 +1802,9 @@ impl KeyInit for Aes192Gcm {
     fn new(key: &aead::Key<Self>) -> Self {
         let mut k = [0u8; 24];
         k.copy_from_slice(key.as_ref());
-        Aes192Gcm { key: k }
+        let out = Aes192Gcm { key: k };
+        k.zeroize();
+        out
     }
 }
 
@@ -1846,7 +1856,9 @@ impl KeyInit for Aes256Gcm {
     fn new(key: &aead::Key<Self>) -> Self {
         let mut k = [0u8; 32];
         k.copy_from_slice(key.as_ref());
-        Aes256Gcm { key: k }
+        let out = Aes256Gcm { key: k };
+        k.zeroize();
+        out
     }
 }
 

wrapper/rust/wolfssl-wolfcrypt/src/chacha20_poly1305.rs

@@ -339,7 +339,9 @@ impl aead::KeyInit for ChaCha20Poly1305Aead {
     fn new(key: &aead::Key<Self>) -> Self {
         let mut k = [0u8; 32];
         k.copy_from_slice(key.as_ref());
-        ChaCha20Poly1305Aead { key: k }
+        let out = ChaCha20Poly1305Aead { key: k };
+        k.zeroize();
+        out
     }
 }
 
@@ -528,7 +530,9 @@ impl aead::KeyInit for XChaCha20Poly1305Aead {
     fn new(key: &aead::Key<Self>) -> Self {
         let mut k = [0u8; 32];
         k.copy_from_slice(key.as_ref());
-        XChaCha20Poly1305Aead { key: k }
+        let out = XChaCha20Poly1305Aead { key: k };
+        k.zeroize();
+        out
     }
 }