一、JNI接口定义文件 NativeApplication.java：
public class NativeApplication{ static { System.loadLibrary("application"); } public static native void check(Application application);} 二、JNI实现文件application.c：
#include#include #include #include #include "md5.h"#define TAG "application"#define LOGI(...) ((void)__android_log_print(ANDROID_LOG_INFO, TAG, __VA_ARGS__))#define LOGW(...) ((void)__android_log_print(ANDROID_LOG_WARN, TAG, __VA_ARGS__))// 签名文件的MD5unsigned char* MD5 = "*********************************";void ByteToHexStr(const unsigned char* source, char* dest, int sourceLen);JNIEXPORT void Java_com_minchu_app_encodedemo_NativeApplication_check(JNIEnv* env,jobject thiz, jobject application) { getSign(env, application);}int getSign(JNIEnv *env, jobject context) { //Context的类 jclass context_clazz = (*env)->GetObjectClass(env, context); // 得到 getPackageManager 方法的 ID jmethodID methodID_getPackageManager = (*env)->GetMethodID(env, context_clazz, "getPackageManager", "()Landroid/content/pm/PackageManager;"); // 获得PackageManager对象 jobject packageManager = (*env)->CallObjectMethod(env, context, methodID_getPackageManager); // 获得 PackageManager 类 jclass pm_clazz = (*env)->GetObjectClass(env, packageManager); // 得到 getPackageInfo 方法的 ID jmethodID methodID_pm = (*env)->GetMethodID(env, pm_clazz, "getPackageInfo", "(Ljava/lang/String;I)Landroid/content/pm/PackageInfo;"); // // 得到 getPackageName 方法的 ID jmethodID methodID_pack = (*env)->GetMethodID(env, context_clazz, "getPackageName", "()Ljava/lang/String;"); // 获得当前应用的包名 jstring application_package = (*env)->CallObjectMethod(env, context, methodID_pack); const char *str = (*env)->GetStringUTFChars(env, application_package, 0); __android_log_print(ANDROID_LOG_DEBUG, "JNI", "packageName: %s\n", str); // 获得PackageInfo jobject packageInfo = (*env)->CallObjectMethod(env, packageManager, methodID_pm, application_package, 64); jclass packageinfo_clazz = (*env)->GetObjectClass(env, packageInfo); jfieldID fieldID_signatures = (*env)->GetFieldID(env, packageinfo_clazz, "signatures", "[Landroid/content/pm/Signature;"); jobjectArray signature_arr = (jobjectArray)(*env)->GetObjectField(env, packageInfo, fieldID_signatures); // Signature数组中取出第一个元素 jobject signature = (*env)->GetObjectArrayElement(env, signature_arr, 0); // 读signature的hashcode jclass signature_clazz = (*env)->GetObjectClass(env, signature); jmethodID methodID_hashcode = (*env)->GetMethodID(env, signature_clazz, "hashCode", "()I"); jint hashCode = (*env)->CallIntMethod(env, signature, methodID_hashcode); // 读signature的byte array jmethodID methodID_toByteArray = (*env)->GetMethodID(env, signature_clazz, "toByteArray", "()[B"); jbyteArray byteArray = (*env)->CallObjectMethod(env, signature, methodID_toByteArray); jsize len = (*env)->GetArrayLength(env, byteArray); // 获取长度 jbyte* bap = (*env)->GetByteArrayElements(env, byteArray, JNI_FALSE); // jbyteArray转为jbyte* char* rtn = NULL; int i=0; int result = 1; if(len > 0) { rtn = (char*)malloc(len+1); // "\0" memcpy(rtn, bap, len); rtn[len]=0; // 注：这里也可以通过回调java的MessageDigest类方法获取MD5 unsigned char decrypt[16]; MD5_CTX mdContext; MD5Init(&mdContext); //初始化 MD5Update(&mdContext, rtn, len); MD5Final(&mdContext, decrypt); char* char_result = (char*) malloc(16*2+1); ByteToHexStr(decrypt, char_result, 16); *(char_result+16*2) = '\0';// 在末尾补\0 LOGI("result:%s\n", char_result); result = strcasecmp(MD5, char_result); free(char_result); } (*env)->ReleaseByteArrayElements(env, byteArray, bap, 0); //释放掉 if (result != 0) { LOGI("result error!"); jclass newExcCls; (*env)->ExceptionDescribe(env); (*env)->ExceptionClear(env); newExcCls = (*env)->FindClass(env, "java/lang/IllegalArgumentException"); if (newExcCls == NULL) { /* Unable to find the exception class, give up. */ return hashCode; } (*env)->ThrowNew(env, newExcCls, "thrown from C code"); } return hashCode;}void ByteToHexStr(const unsigned char* source, char* dest, int sourceLen) { short i; unsigned char highByte, lowByte; for (i = 0; i < sourceLen; i++) { highByte = source[i] >> 4; lowByte = source[i] & 0x0f; highByte += 0x30; if (highByte > 0x39) dest[i * 2] = highByte + 0x07; else dest[i * 2] = highByte; lowByte += 0x30; if (lowByte > 0x39) dest[i * 2 + 1] = lowByte + 0x07; else dest[i * 2 + 1] = lowByte; } return;}
三、MD5算法（网上找的，经过测试可用）：
头文件md5.h：
#ifndef MD5_H #define MD5_H typedef struct { unsigned int count[2]; unsigned int state[4]; unsigned char buffer[64]; }MD5_CTX; #define F(x,y,z) ((x & y) | (~x & z)) #define G(x,y,z) ((x & z) | (y & ~z)) #define H(x,y,z) (x^y^z) #define I(x,y,z) (y ^ (x | ~z)) #define ROTATE_LEFT(x,n) ((x << n) | (x >> (32-n))) #define FF(a,b,c,d,x,s,ac) \{ \a += F(b,c,d) + x + ac; \a = ROTATE_LEFT(a,s); \a += b; \} #define GG(a,b,c,d,x,s,ac) \{ \a += G(b,c,d) + x + ac; \a = ROTATE_LEFT(a,s); \a += b; \} #define HH(a,b,c,d,x,s,ac) \{ \a += H(b,c,d) + x + ac; \a = ROTATE_LEFT(a,s); \a += b; \} #define II(a,b,c,d,x,s,ac) \{ \a += I(b,c,d) + x + ac; \a = ROTATE_LEFT(a,s); \a += b; \} void MD5Init(MD5_CTX *context); void MD5Update(MD5_CTX *context,unsigned char *input,unsigned int inputlen); void MD5Final(MD5_CTX *context,unsigned char digest[16]); void MD5Transform(unsigned int state[4],unsigned char block[64]); void MD5Encode(unsigned char *output,unsigned int *input,unsigned int len); void MD5Decode(unsigned int *output,unsigned char *input,unsigned int len); #endif 实现文件md5.c：
#include#include "md5.h" unsigned char PADDING[]={0x80,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; void MD5Init(MD5_CTX *context) { context->count[0] = 0; context->count[1] = 0; context->state[0] = 0x67452301; context->state[1] = 0xEFCDAB89; context->state[2] = 0x98BADCFE; context->state[3] = 0x10325476; } void MD5Update(MD5_CTX *context,unsigned char *input,unsigned int inputlen) { unsigned int i = 0,index = 0,partlen = 0; index = (context->count[0] >> 3) & 0x3F; partlen = 64 - index; context->count[0] += inputlen << 3; if(context->count[0] < (inputlen << 3)) context->count[1]++; context->count[1] += inputlen >> 29; if(inputlen >= partlen) { memcpy(&context->buffer[index],input,partlen); MD5Transform(context->state,context->buffer); for(i = partlen;i+64 <= inputlen;i+=64) MD5Transform(context->state,&input[i]); index = 0; } else { i = 0; } memcpy(&context->buffer[index],&input[i],inputlen-i); } void MD5Final(MD5_CTX *context,unsigned char digest[16]) { unsigned int index = 0,padlen = 0; unsigned char bits[8]; index = (context->count[0] >> 3) & 0x3F; padlen = (index < 56)?(56-index):(120-index); MD5Encode(bits,context->count,8); MD5Update(context,PADDING,padlen); MD5Update(context,bits,8); MD5Encode(digest,context->state,16); } void MD5Encode(unsigned char *output,unsigned int *input,unsigned int len) { unsigned int i = 0,j = 0; while(j < len) { output[j] = input[i] & 0xFF; output[j+1] = (input[i] >> 8) & 0xFF; output[j+2] = (input[i] >> 16) & 0xFF; output[j+3] = (input[i] >> 24) & 0xFF; i++; j+=4; } } void MD5Decode(unsigned int *output,unsigned char *input,unsigned int len) { unsigned int i = 0,j = 0; while(j < len) { output[i] = (input[j]) | (input[j+1] << 8) | (input[j+2] << 16) | (input[j+3] << 24); i++; j+=4; } } void MD5Transform(unsigned int state[4],unsigned char block[64]) { unsigned int a = state[0]; unsigned int b = state[1]; unsigned int c = state[2]; unsigned int d = state[3]; unsigned int x[64]; MD5Decode(x,block,64); FF(a, b, c, d, x[ 0], 7, 0xd76aa478); FF(d, a, b, c, x[ 1], 12, 0xe8c7b756); FF(c, d, a, b, x[ 2], 17, 0x242070db); FF(b, c, d, a, x[ 3], 22, 0xc1bdceee); FF(a, b, c, d, x[ 4], 7, 0xf57c0faf); FF(d, a, b, c, x[ 5], 12, 0x4787c62a); FF(c, d, a, b, x[ 6], 17, 0xa8304613); FF(b, c, d, a, x[ 7], 22, 0xfd469501); FF(a, b, c, d, x[ 8], 7, 0x698098d8); FF(d, a, b, c, x[ 9], 12, 0x8b44f7af); FF(c, d, a, b, x[10], 17, 0xffff5bb1); FF(b, c, d, a, x[11], 22, 0x895cd7be); FF(a, b, c, d, x[12], 7, 0x6b901122); FF(d, a, b, c, x[13], 12, 0xfd987193); FF(c, d, a, b, x[14], 17, 0xa679438e); FF(b, c, d, a, x[15], 22, 0x49b40821); GG(a, b, c, d, x[ 1], 5, 0xf61e2562); GG(d, a, b, c, x[ 6], 9, 0xc040b340); GG(c, d, a, b, x[11], 14, 0x265e5a51); GG(b, c, d, a, x[ 0], 20, 0xe9b6c7aa); GG(a, b, c, d, x[ 5], 5, 0xd62f105d); GG(d, a, b, c, x[10], 9, 0x2441453); GG(c, d, a, b, x[15], 14, 0xd8a1e681); GG(b, c, d, a, x[ 4], 20, 0xe7d3fbc8); GG(a, b, c, d, x[ 9], 5, 0x21e1cde6); GG(d, a, b, c, x[14], 9, 0xc33707d6); GG(c, d, a, b, x[ 3], 14, 0xf4d50d87); GG(b, c, d, a, x[ 8], 20, 0x455a14ed); GG(a, b, c, d, x[13], 5, 0xa9e3e905); GG(d, a, b, c, x[ 2], 9, 0xfcefa3f8); GG(c, d, a, b, x[ 7], 14, 0x676f02d9); GG(b, c, d, a, x[12], 20, 0x8d2a4c8a); HH(a, b, c, d, x[ 5], 4, 0xfffa3942); HH(d, a, b, c, x[ 8], 11, 0x8771f681); HH(c, d, a, b, x[11], 16, 0x6d9d6122); HH(b, c, d, a, x[14], 23, 0xfde5380c); HH(a, b, c, d, x[ 1], 4, 0xa4beea44); HH(d, a, b, c, x[ 4], 11, 0x4bdecfa9); HH(c, d, a, b, x[ 7], 16, 0xf6bb4b60); HH(b, c, d, a, x[10], 23, 0xbebfbc70); HH(a, b, c, d, x[13], 4, 0x289b7ec6); HH(d, a, b, c, x[ 0], 11, 0xeaa127fa); HH(c, d, a, b, x[ 3], 16, 0xd4ef3085); HH(b, c, d, a, x[ 6], 23, 0x4881d05); HH(a, b, c, d, x[ 9], 4, 0xd9d4d039); HH(d, a, b, c, x[12], 11, 0xe6db99e5); HH(c, d, a, b, x[15], 16, 0x1fa27cf8); HH(b, c, d, a, x[ 2], 23, 0xc4ac5665); II(a, b, c, d, x[ 0], 6, 0xf4292244); II(d, a, b, c, x[ 7], 10, 0x432aff97); II(c, d, a, b, x[14], 15, 0xab9423a7); II(b, c, d, a, x[ 5], 21, 0xfc93a039); II(a, b, c, d, x[12], 6, 0x655b59c3); II(d, a, b, c, x[ 3], 10, 0x8f0ccc92); II(c, d, a, b, x[10], 15, 0xffeff47d); II(b, c, d, a, x[ 1], 21, 0x85845dd1); II(a, b, c, d, x[ 8], 6, 0x6fa87e4f); II(d, a, b, c, x[15], 10, 0xfe2ce6e0); II(c, d, a, b, x[ 6], 15, 0xa3014314); II(b, c, d, a, x[13], 21, 0x4e0811a1); II(a, b, c, d, x[ 4], 6, 0xf7537e82); II(d, a, b, c, x[11], 10, 0xbd3af235); II(c, d, a, b, x[ 2], 15, 0x2ad7d2bb); II(b, c, d, a, x[ 9], 21, 0xeb86d391); state[0] += a; state[1] += b; state[2] += c; state[3] += d; }
四、Android.mk脚本：
LOCAL_PATH := $(call my-dir)#########################################include $(CLEAR_VARS)LOCAL_MODULE := applicationLOCAL_SRC_FILES := application.c md5.cLOCAL_LDLIBS := -lloginclude $(BUILD_SHARED_LIBRARY)
总结：在合适的地方调用NativeApplication的check方法，如果当前应用的签名md5有问题，会抛出异常。