crypto: add 3des-ede support when using libgcrypt/nettle

Libgcrypt and nettle support 3des-ede, so this patch add 3des-ede
support when using libgcrypt or nettle.

Reviewed-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
diff --git a/crypto/cipher.c b/crypto/cipher.c
index a9bca41..9ecaff7 100644
--- a/crypto/cipher.c
+++ b/crypto/cipher.c
@@ -28,6 +28,7 @@
     [QCRYPTO_CIPHER_ALG_AES_192] = 24,
     [QCRYPTO_CIPHER_ALG_AES_256] = 32,
     [QCRYPTO_CIPHER_ALG_DES_RFB] = 8,
+    [QCRYPTO_CIPHER_ALG_3DES] = 24,
     [QCRYPTO_CIPHER_ALG_CAST5_128] = 16,
     [QCRYPTO_CIPHER_ALG_SERPENT_128] = 16,
     [QCRYPTO_CIPHER_ALG_SERPENT_192] = 24,
@@ -42,6 +43,7 @@
     [QCRYPTO_CIPHER_ALG_AES_192] = 16,
     [QCRYPTO_CIPHER_ALG_AES_256] = 16,
     [QCRYPTO_CIPHER_ALG_DES_RFB] = 8,
+    [QCRYPTO_CIPHER_ALG_3DES] = 8,
     [QCRYPTO_CIPHER_ALG_CAST5_128] = 8,
     [QCRYPTO_CIPHER_ALG_SERPENT_128] = 16,
     [QCRYPTO_CIPHER_ALG_SERPENT_192] = 16,
@@ -107,8 +109,9 @@
     }
 
     if (mode == QCRYPTO_CIPHER_MODE_XTS) {
-        if (alg == QCRYPTO_CIPHER_ALG_DES_RFB) {
-            error_setg(errp, "XTS mode not compatible with DES-RFB");
+        if (alg == QCRYPTO_CIPHER_ALG_DES_RFB
+                || alg == QCRYPTO_CIPHER_ALG_3DES) {
+            error_setg(errp, "XTS mode not compatible with DES-RFB/3DES");
             return false;
         }
         if (nkey % 2) {