From 8d60d90ce8200c91ca5f0123f66ed645f3321c7b Mon Sep 17 00:00:00 2001
From: Justus Winter <justus@sequoia-pgp.org>
Date: Tue, 15 Feb 2022 12:21:36 +0100
Subject: openpgp: Fix crash converting nonce slices to arrays.

  - Doing the conversion before matching on the algorithm tries to
    convert nonces of different sizes to an array suitable for EAX,
    leading to a panic.
---
 openpgp/src/crypto/backend/cng/aead.rs | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/openpgp/src/crypto/backend/cng/aead.rs b/openpgp/src/crypto/backend/cng/aead.rs
index ff302dad..aaa9c854 100644
--- a/openpgp/src/crypto/backend/cng/aead.rs
+++ b/openpgp/src/crypto/backend/cng/aead.rs
@@ -27,12 +27,11 @@ impl AEADAlgorithm {
         op: CipherOp,
     ) -> Result<Box<dyn Aead>> {
 
-        let nonce = GenericArray::from_slice(nonce);
-
         match self {
             AEADAlgorithm::EAX => match sym_algo {
                 | SymmetricAlgorithm::AES128 => {
                     let key = GenericArray::from_slice(key);
+                    let nonce = GenericArray::from_slice(nonce);
                     Ok(match op {
                         CipherOp::Encrypt =>
                             Box::new(EaxOnline::<BlockCipherKey<Aes, U128>, Encrypt>::with_key_and_nonce(key, nonce)),
@@ -42,6 +41,7 @@ impl AEADAlgorithm {
                 }
                 SymmetricAlgorithm::AES192 => {
                     let key = GenericArray::from_slice(key);
+                    let nonce = GenericArray::from_slice(nonce);
                     Ok(match op {
                         CipherOp::Encrypt =>
                             Box::new(EaxOnline::<BlockCipherKey<Aes, U192>, Encrypt>::with_key_and_nonce(key, nonce)),
@@ -51,6 +51,7 @@ impl AEADAlgorithm {
                 }
                 SymmetricAlgorithm::AES256 => {
                     let key = GenericArray::from_slice(key);
+                    let nonce = GenericArray::from_slice(nonce);
                     Ok(match op {
                         CipherOp::Encrypt =>
                             Box::new(EaxOnline::<BlockCipherKey<Aes, U256>, Encrypt>::with_key_and_nonce(key, nonce)),
-- 
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