使用上层秘钥解密终端识别码密钥后再次加密连接设备

2025-07-28 10:40:00 +08:00
parent d58923fd21
commit 492193f848
4 changed files with 75 additions and 4 deletions
--- a/misc/my_encrypt.cpp
+++ b/misc/my_encrypt.cpp
@@ -60,8 +60,61 @@ using namespace std;
 	sm4Encode.sm4_enc(input,strlen(input),output,szKey); 
 }

-//////////////////////////////////////////////////////////////////////////////////////////////////
+//////////////////////////////////////////////////////////////////////////////////////////////////lnk20250728

+/**
+ * SM4 ECB <20><><EFBFBD>ܺ<EFBFBD><DCBA><EFBFBD><EFBFBD><EFBFBD>ZeroPadding<6E><67>
+ * @param encrypted_base64_str <20><><EFBFBD>ܺ<EFBFBD><DCBA><EFBFBD> Base64 <20>ַ<EFBFBD><D6B7><EFBFBD>
+ * @param key_str 16<31>ֽ<EFBFBD><D6BD><EFBFBD>Կ<EFBFBD><D4BF><EFBFBD><EFBFBD><EFBFBD>ģ<EFBFBD>
+ * @param decrypted_output <20><><EFBFBD>ܺ<EFBFBD><DCBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ɵ<EFBFBD><C9B5><EFBFBD><EFBFBD><EFBFBD>Ԥ<EFBFBD>ȷ<EFBFBD><C8B7><EFBFBD><EFBFBD>ڴ<EFBFBD>
+ * @return 0 <20>ɹ<EFBFBD><C9B9><EFBFBD><EFBFBD><EFBFBD> 0 ʧ<><CAA7>
+ */
+// ע<>⣺<EFBFBD><E2A3BA><EFBFBD><EFBFBD>ʹ<EFBFBD><CAB9> ZeroPadding<6E><67><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫȥ<D2AA><C8A5>ĩβ 0
+int sm4_ecb_decrypt_zeropad_base64(const char* base64_cipher, const char* key_str, char* plaintext_out) {
+    if (!base64_cipher || !key_str || !plaintext_out) {
+        return -1;
+    }

+    // base64 decode
+    unsigned char cipher_bin[256] = {0};
+	long cipher_len = 0;                   // <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
+    int ret = base64_decode(base64_cipher, strlen(base64_cipher),
+                        (char*)cipher_bin, &cipher_len);
+	if (ret != 0) {
+    	// <20><><EFBFBD><EFBFBD>ʧ<EFBFBD>ܴ<EFBFBD><DCB4><EFBFBD>
+    	return -1;
+	}
+	
+    if (cipher_len <= 0 || cipher_len % 16 != 0) {
+        return -2; // SM4 <20>鳤<EFBFBD>ȱ<EFBFBD><C8B1><EFBFBD>Ϊ 16 <20>ı<EFBFBD><C4B1><EFBFBD>
+    }

+    // ׼<><D7BC> key
+    if (strlen(key_str) != 16) {
+        return -3; // SM4 Ҫ<><D2AA><EFBFBD><EFBFBD>Կ<EFBFBD><D4BF> 16 <20>ֽ<EFBFBD>
+    }
+
+    unsigned char key_bin[16] = {0};
+    memcpy(key_bin, key_str, 16);
+
+    // <20><>ʼ<EFBFBD><CABC> SM4 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
+    sm4_context ctx;
+    SM4 sm4;
+    sm4.sm4_setkey_dec(&ctx, key_bin);
+
+    // <20><><EFBFBD><EFBFBD>
+    unsigned char plain_buf[256] = {0};
+    sm4.sm4_crypt_ecb(&ctx, SM4_DECRYPT, cipher_len, cipher_bin, plain_buf);
+
+    // ȥ<><C8A5> zero padding<6E><67>ĩβ<C4A9><CEB2> 0x00<30><30>
+    int plain_len = cipher_len;
+    while (plain_len > 0 && plain_buf[plain_len - 1] == 0x00) {
+        plain_len--;
+    }
+
+    memcpy(plaintext_out, plain_buf, plain_len);
+    plaintext_out[plain_len] = '\0';
+
+    return 0;
+}