diff --git a/README.md b/README.md
index 858421dc..9def6502 100644
--- a/README.md
+++ b/README.md
@@ -24,6 +24,39 @@ make test
 sudo make install
 ```
 
+### Visual Studio环境编译
+
+在Visual Studio命令提示符下执行：
+
+```bash
+mkdir build
+cd build
+cmake .. -G "NMake Makefiles"
+nmake
+```
+
+### iOS编译
+
+下载 https://github.com/leetal/ios-cmake，将`ios.toolchain.cmake`文件复制到`build`目录。
+
+```bash
+mkdir build; cd build
+cmake .. -G Xcode -DCMAKE_TOOLCHAIN_FILE=../ios.toolchain.cmake -DPLATFORM=OS64
+cmake --build . --config Release
+```
+
+如果出现“error: Signing for "gmssl" requires a development team.”错误，可以用Xcode打开工程文件，在Signing配置中设置Development Team。
+
+### Android编译
+
+下载Android NDK，执行
+
+```bash
+mkdir build; cd build
+cmake .. -DCMAKE_TOOLCHAIN_FILE=$NDK/build/cmake/android.toolchain.cmake  -DANDROID_ABI=arm64-v8a  -DANDROID_PLATFORM=android-23
+make
+```
+
 ## 主要功能
 
 ### 密码算法
@@ -68,3 +101,4 @@ GmSSL支持Nginx的适配，并提供了Docker实现，具体参见[Nginx-with-G
 - [ ] Add GCM cipher suites
 - [ ] Release official open interfaces
 - [ ] **Version 3.2.0 release**
+
diff --git a/tests/hmactest.c b/tests/hmactest.c
index 6efb1128..5b7c289f 100644
--- a/tests/hmactest.c
+++ b/tests/hmactest.c
@@ -84,25 +84,27 @@ struct {
 int test_hmac(const DIGEST *digest, const char *key_hex, const char *data_hex, const char *hmac_hex)
 {
 	HMAC_CTX ctx;
-	uint8_t key = malloc(strlen(key_hex)/2); // FIXME: malloc
-	uint8_t data = malloc(strlen(data_hex)/2);
-	uint8_t hmac = malloc(strlen(hmac_hex) / 2);
+	uint8_t *key = (uint8_t *)malloc(strlen(key_hex)/2);
+	uint8_t *data = (uint8_t *)malloc(strlen(data_hex)/2);
+	uint8_t *hmac = (uint8_t *)malloc(strlen(hmac_hex) / 2);
+	size_t keylen, datalen, hmaclen;
 	uint8_t buf[64];
-	size_t len;
+	size_t buflen;
 
-	hex_to_bytes(key_hex, strlen(key_hex), key, &len);
-	hex_to_bytes(data_hex, strlen(data_hex), data, &len);
-	hex_to_bytes(hmac_hex, strlen(hmac_hex), hmac, &len);
+	hex_to_bytes(key_hex, strlen(key_hex), key, &keylen);
+	hex_to_bytes(data_hex, strlen(data_hex), data, &datalen);
+	hex_to_bytes(hmac_hex, strlen(hmac_hex), hmac, &hmaclen);
 
-	hmac_init(&ctx, digest, key, sizeof(key));
-	hmac_update(&ctx, data, sizeof(data));
-	hmac_finish(&ctx, buf, &len);
+	hmac_init(&ctx, digest, key, keylen);
+	hmac_update(&ctx, data, datalen);
+	hmac_finish(&ctx, buf, &buflen);
 
-	if (len != sizeof(hmac) || memcmp(buf, hmac, sizeof(hmac)) != 0) {
+	if (buflen !=  hmaclen || memcmp(buf, hmac, hmaclen) != 0) {
 		printf("failed\n");
 		return 0;
 	}
 	printf("ok\n");
+
 	if (key) free(key);
 	if (data) free(data);
 	if (hmac) free(hmac);