怎样在Android Native项目中使用OpenSSL?

sugelawa

我需要用到OpenSSL的RSA在项目中，我从OpenSSL1.0.1cForAndroid下载了源码然后成功编译得到libcrypto.so 和libssl.so。我将这两个文件拷贝到$(MY_PROJECT)/jni/lib/，然后在jni的Android.mk中这样引用：

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)
LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
LOCAL_LIBS := $(LOCAL_PATH)/lib
LOCAL_STATIC_LIBRARIES := libcrypto libssl
LOCAL_LDLIBS := -llog
LOCAL_MODULE := jni

LOCAL_SRC_FILES := jni.c

include $(BUILD_SHARED_LIBRARY)


然后在代码中这样测试：

#include <stdio.h>
#include <string.h>

#include <openssl/rsa.h>

#define nr_bits 2048

int test_openssl()
{
  RSA *rsa = RSA_generate_key(nr_bits, 65537, NULL, NULL);
  return 0;
}


编译的时候报错:

....jni/test.c:10: error: undefined reference to 'RSA_generate_key'
collect2: ld returned 1 exit status


谁知道怎么回事吗？是link libcrypto.so的方式有问题吗还是怎么回事？

rover12421

2个修改
1.修改mk文件

1. LOCAL_PATH := $(call my-dir)
   
2. 
   
3. include $(CLEAR_VARS)
   
4. LOCAL_MODULE := crypto
   
5. LOCAL_SRC_FILES := lib/libcrypto.so
   
6. LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/include
   
7. include $(PREBUILT_SHARED_LIBRARY)
   
8. 
   
9. include $(CLEAR_VARS)
   
10. LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
    
11. LOCAL_LIBS := $(LOCAL_PATH)/lib
    
12. LOCAL_STATIC_LIBRARIES := libcrypto libssl
    
13. LOCAL_LDLIBS := -llog
    
14. LOCAL_MODULE := jni
    
15. 
    
16. LOCAL_SRC_FILES := jni.c
    
17. 
    
18. include $(BUILD_SHARED_LIBRARY)

复制代码

2.修改openssl中的android-config.mk重新编译
#LOCAL_CFLAGS += -DOPENSSL_NO_DEPRECATED
这一行注释掉
查看rsa.h可以看到原因:

1. /* Deprecated version */
   
2. #ifndef OPENSSL_NO_DEPRECATED
   
3. RSA *        RSA_generate_key(int bits, unsigned long e,void
   
4.                 (*callback)(int,int,void *),void *cb_arg);
   
5. #endif /* !defined(OPENSSL_NO_DEPRECATED) */
   
6. 
   
7. /* New version */
   
8. int        RSA_generate_key_ex(RSA *rsa, int bits, BIGNUM *e, BN_GENCB *cb);

复制代码

一测试通过.
如果不改2,你可以用new版本的RSA_generate_key_ex

sugelawa

回复 2# rover12421 太厉害了，直接命中要害！3Q