Not all paths in qcrypto_cipher_ctx_new() were correctly distinguishing
between valid user input for cipher mode (which should report a user
facing error), vs program logic errors (which should assert).

Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
 crypto/cipher-nettle.c.inc | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/crypto/cipher-nettle.c.inc b/crypto/cipher-nettle.c.inc
index 766de036ba..2654b439c1 100644
--- a/crypto/cipher-nettle.c.inc
+++ b/crypto/cipher-nettle.c.inc
@@ -525,8 +525,10 @@ static QCryptoCipher *qcrypto_cipher_ctx_new(QCryptoCipherAlgorithm alg,
             case QCRYPTO_CIPHER_MODE_CTR:
                 drv = &qcrypto_nettle_des_driver_ctr;
                 break;
-            default:
+            case QCRYPTO_CIPHER_MODE_XTS:
                 goto bad_cipher_mode;
+            default:
+                g_assert_not_reached();
             }
 
             ctx = g_new0(QCryptoNettleDES, 1);
@@ -551,8 +553,10 @@ static QCryptoCipher *qcrypto_cipher_ctx_new(QCryptoCipherAlgorithm alg,
             case QCRYPTO_CIPHER_MODE_CTR:
                 drv = &qcrypto_nettle_des3_driver_ctr;
                 break;
-            default:
+            case QCRYPTO_CIPHER_MODE_XTS:
                 goto bad_cipher_mode;
+            default:
+                g_assert_not_reached();
             }
 
             ctx = g_new0(QCryptoNettleDES3, 1);
@@ -663,8 +667,10 @@ static QCryptoCipher *qcrypto_cipher_ctx_new(QCryptoCipherAlgorithm alg,
             case QCRYPTO_CIPHER_MODE_CTR:
                 drv = &qcrypto_nettle_cast128_driver_ctr;
                 break;
-            default:
+            case QCRYPTO_CIPHER_MODE_XTS:
                 goto bad_cipher_mode;
+            default:
+                g_assert_not_reached();
             }
 
             ctx = g_new0(QCryptoNettleCAST128, 1);
@@ -741,8 +747,12 @@ static QCryptoCipher *qcrypto_cipher_ctx_new(QCryptoCipherAlgorithm alg,
             case QCRYPTO_CIPHER_MODE_ECB:
                 drv = &qcrypto_nettle_sm4_driver_ecb;
                 break;
-            default:
+            case QCRYPTO_CIPHER_MODE_CBC:
+            case QCRYPTO_CIPHER_MODE_CTR:
+            case QCRYPTO_CIPHER_MODE_XTS:
                 goto bad_cipher_mode;
+            default:
+                g_assert_not_reached();
             }
 
             ctx = g_new0(QCryptoNettleSm4, 1);
-- 
2.45.2