crypto: Introduce SM4 symmetric cipher algorithm

Introduce the SM4 cipher algorithms (OSCCA GB/T 32907-2016).

SM4 (GBT.32907-2016) is a cryptographic standard issued by the
Organization of State Commercial Administration of China (OSCCA)
as an authorized cryptographic algorithms for the use within China.

Detect the SM4 cipher algorithms and enable the feature silently
if it is available.

Signed-off-by: Hyman Huang <yong.huang@smartx.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

1 files changed, 49 insertions, 0 deletions

diff --git a/crypto/cipher-nettle.c.inc b/crypto/cipher-nettle.c.inc
index 24cc61f87b..42b39e18a2 100644
--- a/crypto/cipher-nettle.c.inc
+++ b/crypto/cipher-nettle.c.inc
@@ -33,6 +33,9 @@
 #ifndef CONFIG_QEMU_PRIVATE_XTS
 #include <nettle/xts.h>
 #endif
+#ifdef CONFIG_CRYPTO_SM4
+#include <nettle/sm4.h>
+#endif
 
 static inline bool qcrypto_length_check(size_t len, size_t blocksize,
                                         Error **errp)
@@ -426,6 +429,30 @@ DEFINE_ECB_CBC_CTR_XTS(qcrypto_nettle_twofish,
                        QCryptoNettleTwofish, TWOFISH_BLOCK_SIZE,
                        twofish_encrypt_native, twofish_decrypt_native)
 
+#ifdef CONFIG_CRYPTO_SM4
+typedef struct QCryptoNettleSm4 {
+    QCryptoCipher base;
+    struct sm4_ctx key[2];
+} QCryptoNettleSm4;
+
+static void sm4_encrypt_native(void *ctx, size_t length,
+                               uint8_t *dst, const uint8_t *src)
+{
+    struct sm4_ctx *keys = ctx;
+    sm4_crypt(&keys[0], length, dst, src);
+}
+
+static void sm4_decrypt_native(void *ctx, size_t length,
+                               uint8_t *dst, const uint8_t *src)
+{
+    struct sm4_ctx *keys = ctx;
+    sm4_crypt(&keys[1], length, dst, src);
+}
+
+DEFINE_ECB(qcrypto_nettle_sm4,
+           QCryptoNettleSm4, SM4_BLOCK_SIZE,
+           sm4_encrypt_native, sm4_decrypt_native)
+#endif
 
 bool qcrypto_cipher_supports(QCryptoCipherAlgorithm alg,
                              QCryptoCipherMode mode)
@@ -443,6 +470,9 @@ bool qcrypto_cipher_supports(QCryptoCipherAlgorithm alg,
     case QCRYPTO_CIPHER_ALG_TWOFISH_128:
     case QCRYPTO_CIPHER_ALG_TWOFISH_192:
     case QCRYPTO_CIPHER_ALG_TWOFISH_256:
+#ifdef CONFIG_CRYPTO_SM4
+    case QCRYPTO_CIPHER_ALG_SM4:
+#endif
         break;
     default:
         return false;
@@ -701,6 +731,25 @@ static QCryptoCipher *qcrypto_cipher_ctx_new(QCryptoCipherAlgorithm alg,
 
             return &ctx->base;
         }
+#ifdef CONFIG_CRYPTO_SM4
+    case QCRYPTO_CIPHER_ALG_SM4:
+        {
+            QCryptoNettleSm4 *ctx = g_new0(QCryptoNettleSm4, 1);
+
+            switch (mode) {
+            case QCRYPTO_CIPHER_MODE_ECB:
+                ctx->base.driver = &qcrypto_nettle_sm4_driver_ecb;
+                break;
+            default:
+                goto bad_cipher_mode;
+            }
+
+            sm4_set_encrypt_key(&ctx->key[0], key);
+            sm4_set_decrypt_key(&ctx->key[1], key);
+
+            return &ctx->base;
+        }
+#endif
 
     default:
         error_setg(errp, "Unsupported cipher algorithm %s",