笔者在第 4 小节里基于前 3 小结的知识点简单扩展了一个 md5()
方法并成功在 JS 代码里调起了 C++ 代码,本节笔者简单介绍一下引入三方库编译的知识点。
上一小节的 md5()
方法实现只是简单模拟,并没有真正实现 MD5 的计算,因此笔者从网上找了一个 MD5 计算的源码并引入工程,工程目录如下所示:
其中 md5.h
源码如下所示:
//
// Created on 2023/2/28.
//
// Node APIs are not fully supported. To solve the compilation error of the interface cannot be found,
// please include "napi/native_api.h".
#ifndef oh_0400_napi_md5_H
#define oh_0400_napi_md5_H
/* Parameters of MD5\. */
#define s11 7
#define s12 12
#define s13 17
#define s14 22
#define s21 5
#define s22 9
#define s23 14
#define s24 20
#define s31 4
#define s32 11
#define s33 16
#define s34 23
#define s41 6
#define s42 10
#define s43 15
#define s44 21
#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 ROTATELEFT(num, n) (((num) << (n)) | ((num) >> (32-(n))))
#define FF(a, b, c, d, x, s, ac) { \
(a) += F ((b), (c), (d)) + (x) + ac; \
(a) = ROTATELEFT ((a), (s)); \
(a) += (b); \
}
#define GG(a, b, c, d, x, s, ac) { \
(a) += G ((b), (c), (d)) + (x) + ac; \
(a) = ROTATELEFT ((a), (s)); \
(a) += (b); \
}
#define HH(a, b, c, d, x, s, ac) { \
(a) += H ((b), (c), (d)) + (x) + ac; \
(a) = ROTATELEFT ((a), (s)); \
(a) += (b); \
}
#define II(a, b, c, d, x, s, ac) { \
(a) += I ((b), (c), (d)) + (x) + ac; \
(a) = ROTATELEFT ((a), (s)); \
(a) += (b); \
}
#include <string>
#include <cstring>
using std::string;
/* Define of btye.*/
typedef unsigned char byte;
/* Define of byte. */
typedef unsigned int bit32;
class MD5 {
public:
/* Construct a MD5 object with a string. */
MD5(const string& message);
/* Generate md5 digest. */
const byte* getDigest();
/* Convert digest to string value */
string toStr();
private:
/* Initialization the md5 object, processing another message block,
* and updating the context.*/
void init(const byte* input, size_t len);
/* MD5 basic transformation. Transforms state based on block. */
void transform(const byte block[64]);
/* Encodes input (usigned long) into output (byte). */
void encode(const bit32* input, byte* output, size_t length);
/* Decodes input (byte) into output (usigned long). */
void decode(const byte* input, bit32* output, size_t length);
private:
/* Flag for mark whether calculate finished. */
bool finished;
/* state (ABCD). */
bit32 state[4];
/* number of bits, low-order word first. */
bit32 count[2];
/* input buffer. */
byte buffer[64];
/* message digest. */
byte digest[16];
/* padding for calculate. */
static const byte PADDING[64];
/* Hex numbers. */
static const char HEX_NUMBERS[16];
};
#endif //oh_0400_napi_md5_H
md5.cpp
源码如下所示:
//
// Created on 2023/2/28.
//
// Node APIs are not fully supported. To solve the compilation error of the interface cannot be found,
// please include "napi/native_api.h".
#include "md5.h"
#include <string>
/* Define the static member of MD5\. */
const byte MD5::PADDING[64] = { 0x80 };
const char MD5::HEX_NUMBERS[16] = {
'0', '1', '2', '3',
'4', '5', '6', '7',
'8', '9', 'a', 'b',
'c', 'd', 'e', 'f'
};
MD5::MD5(const string& message) {
finished = false;
/* Reset number of bits. */
count[0] = count[1] = 0;
/* Initialization constants. */
state[0] = 0x67452301;
state[1] = 0xefcdab89;
state[2] = 0x98badcfe;
state[3] = 0x10325476;
/* Initialization the object according to message. */
init((const byte*)message.c_str(), message.length());
}
/**
* @Generate md5 digest.
*
* @return the message-digest.
*
*/
const byte* MD5::getDigest() {
if (!finished) {
finished = true;
byte bits[8];
bit32 oldState[4];
bit32 oldCount[2];
bit32 index, padLen;
/* Save current state and count. */
memcpy(oldState, state, 16);
memcpy(oldCount, count, 8);
/* Save number of bits */
encode(count, bits, 8);
/* Pad out to 56 mod 64\. */
index = (bit32)((count[0] >> 3) & 0x3f);
padLen = (index < 56) ? (56 - index) : (120 - index);
init(PADDING, padLen);
/* Append length (before padding) */
init(bits, 8);
/* Store state in digest */
encode(state, digest, 16);
/* Restore current state and count. */
memcpy(state, oldState, 16);
memcpy(count, oldCount, 8);
}
return digest;
}
/**
* @Initialization the md5 object, processing another message block,
* and updating the context.
*
* @param {input} the input message.
*
* @param {len} the number btye of message.
*
*/
void MD5::init(const byte* input, size_t len) {
bit32 i, index, partLen;
finished = false;
/* Compute number of bytes mod 64 */
index = (bit32)((count[0] >> 3) & 0x3f);
/* update number of bits */
if ((count[0] += ((bit32)len << 3)) < ((bit32)len << 3)) {
++count[1];
}
count[1] += ((bit32)len >> 29);
partLen = 64 - index;
/* transform as many times as possible. */
if (len >= partLen) {
memcpy(&buffer[index], input, partLen);
transform(buffer);
for (i = partLen; i + 63 < len; i += 64) {
transform(&input[i]);
}
index = 0;
} else {
i = 0;
}
/* Buffer remaining input */
memcpy(&buffer[index], &input[i], len - i);
}
void MD5::transform(const byte block[64]) {
bit32 a = state[0], b = state[1], c = state[2], d = state[3], x[16];
decode(block, x, 64);
/* Round 1 */
FF (a, b, c, d, x[ 0], s11, 0xd76aa478);
FF (d, a, b, c, x[ 1], s12, 0xe8c7b756);
FF (c, d, a, b, x[ 2], s13, 0x242070db);
FF (b, c, d, a, x[ 3], s14, 0xc1bdceee);
FF (a, b, c, d, x[ 4], s11, 0xf57c0faf);
FF (d, a, b, c, x[ 5], s12, 0x4787c62a);
FF (c, d, a, b, x[ 6], s13, 0xa8304613);
FF (b, c, d, a, x[ 7], s14, 0xfd469501);
FF (a, b, c, d, x[ 8], s11, 0x698098d8);
FF (d, a, b, c, x[ 9], s12, 0x8b44f7af);
FF (c, d, a, b, x[10], s13, 0xffff5bb1);
FF (b, c, d, a, x[11], s14, 0x895cd7be);
FF (a, b, c, d, x[12], s11, 0x6b901122);
FF (d, a, b, c, x[13], s12, 0xfd987193);
FF (c, d, a, b, x[14], s13, 0xa679438e);
FF (b, c, d, a, x[15], s14, 0x49b40821);
/* Round 2 */
GG (a, b, c, d, x[ 1], s21, 0xf61e2562);
GG (d, a, b, c, x[ 6], s22, 0xc040b340);
GG (c, d, a, b, x[11], s23, 0x265e5a51);
GG (b, c, d, a, x[ 0], s24, 0xe9b6c7aa);
GG (a, b, c, d, x[ 5], s21, 0xd62f105d);
GG (d, a, b, c, x[10], s22, 0x2441453);
GG (c, d, a, b, x[15], s23, 0xd8a1e681);
GG (b, c, d, a, x[ 4], s24, 0xe7d3fbc8);
GG (a, b, c, d, x[ 9], s21, 0x21e1cde6);
GG (d, a, b, c, x[14], s22, 0xc33707d6);
GG (c, d, a, b, x[ 3], s23, 0xf4d50d87);
GG (b, c, d, a, x[ 8], s24, 0x455a14ed);
GG (a, b, c, d, x[13], s21, 0xa9e3e905);
GG (d, a, b, c, x[ 2], s22, 0xfcefa3f8);
GG (c, d, a, b, x[ 7], s23, 0x676f02d9);
GG (b, c, d, a, x[12], s24, 0x8d2a4c8a);
/* Round 3 */
HH (a, b, c, d, x[ 5], s31, 0xfffa3942);
HH (d, a, b, c, x[ 8], s32, 0x8771f681);
HH (c, d, a, b, x[11], s33, 0x6d9d6122);
HH (b, c, d, a, x[14], s34, 0xfde5380c);
HH (a, b, c, d, x[ 1], s31, 0xa4beea44);
HH (d, a, b, c, x[ 4], s32, 0x4bdecfa9);
HH (c, d, a, b, x[ 7], s33, 0xf6bb4b60);
HH (b, c, d, a, x[10], s34, 0xbebfbc70);
HH (a, b, c, d, x[13], s31, 0x289b7ec6);
HH (d, a, b, c, x[ 0], s32, 0xeaa127fa);
HH (c, d, a, b, x[ 3], s33, 0xd4ef3085);
HH (b, c, d, a, x[ 6], s34, 0x4881d05);
HH (a, b, c, d, x[ 9], s31, 0xd9d4d039);
HH (d, a, b, c, x[12], s32, 0xe6db99e5);
HH (c, d, a, b, x[15], s33, 0x1fa27cf8);
HH (b, c, d, a, x[ 2], s34, 0xc4ac5665);
/* Round 4 */
II (a, b, c, d, x[ 0], s41, 0xf4292244);
II (d, a, b, c, x[ 7], s42, 0x432aff97);
II (c, d, a, b, x[14], s43, 0xab9423a7);
II (b, c, d, a, x[ 5], s44, 0xfc93a039);
II (a, b, c, d, x[12], s41, 0x655b59c3);
II (d, a, b, c, x[ 3], s42, 0x8f0ccc92);
II (c, d, a, b, x[10], s43, 0xffeff47d);
II (b, c, d, a, x[ 1], s44, 0x85845dd1);
II (a, b, c, d, x[ 8], s41, 0x6fa87e4f);
II (d, a, b, c, x[15], s42, 0xfe2ce6e0);
II (c, d, a, b, x[ 6], s43, 0xa3014314);
II (b, c, d, a, x[13], s44, 0x4e0811a1);
II (a, b, c, d, x[ 4], s41, 0xf7537e82);
II (d, a, b, c, x[11], s42, 0xbd3af235);
II (c, d, a, b, x[ 2], s43, 0x2ad7d2bb);
II (b, c, d, a, x[ 9], s44, 0xeb86d391);
state[0] += a;
state[1] += b;
state[2] += c;
state[3] += d;
}
/**
* @Encodes input (unsigned long) into output (byte).
*
* @param {input} usigned long.
*
* @param {output} byte.
*
* @param {length} the length of input.
*
*/
void MD5::encode(const bit32* input, byte* output, size_t length) {
for (size_t i = 0, j = 0; j < length; ++i, j += 4) {
output[j]= (byte)(input[i] & 0xff);
output[j + 1] = (byte)((input[i] >> 8) & 0xff);
output[j + 2] = (byte)((input[i] >> 16) & 0xff);
output[j + 3] = (byte)((input[i] >> 24) & 0xff);
}
}
/**
* @Decodes input (byte) into output (usigned long).
*
* @param {input} bytes.
*
* @param {output} unsigned long.
*
* @param {length} the length of input.
*
*/
void MD5::decode(const byte* input, bit32* output, size_t length) {
for (size_t i = 0, j = 0; j < length; ++i, j += 4) {
output[i] = ((bit32)input[j]) | (((bit32)input[j + 1]) << 8) |
(((bit32)input[j + 2]) << 16) | (((bit32)input[j + 3]) << 24);
}
}
/**
* @Convert digest to string value.
*
* @return the hex string of digest.
*
*/
string MD5::toStr() {
const byte* digest_ = getDigest();
string str;
str.reserve(16 << 1);
for (size_t i = 0; i < 16; ++i) {
int t = digest_[i];
int a = t / 16;
int b = t % 16;
str.append(1, HEX_NUMBERS[a]);
str.append(1, HEX_NUMBERS[b]);
}
return str;
}
引入 MD5 算法后,就可以在 hello.cpp 里的 Md5()
方法内实现 MD5 算法了,使用流程如下:
引入头文件的目的是调用其提供的 MD5 计算方法,和 JS 里的 import
功能类似。
#include "./md5/md5.h"
修改 hello.cpp 里的 Md5()
方法内容如下所示:
static napi_value Md5(napi_env env, napi_callback_info info) {
// 1、从info中取出JS传递过来的参数放入args
size_t argc = 1;
napi_value args[1] = { nullptr };
if (napi_ok != napi_get_cb_info(env, info, &argc, args, nullptr, nullptr)) {
napi_throw_error(env, "-1000", "napi_get_cb_info error");
return nullptr;
}
// 2、获取参数的类型
napi_valuetype stringType;
if (napi_ok != napi_typeof(env, args[0], &stringType)) {
napi_throw_error(env, "-1001", "napi_typeof error");
return nullptr;
}
// 3、如果参数为null,这抛异常
if (napi_null == stringType) {
napi_throw_error(env, "-1002", "the param can't be null");
return nullptr;
}
// 4、获取传递的string长度
size_t length = 0;
if (napi_ok != napi_get_value_string_utf8(env, args[0], nullptr, 0, &length)) {
napi_throw_error(env, "-1003", "napi_get_value_string_utf8 error");
return nullptr;
}
// 5、如果传递的是"",则抛异常
if (length == 0) {
napi_throw_error(env, "-1004", "the param length invalid");
return nullptr;
}
// 6、读取传递的string参数放入buffer中
char* buffer = new char[length + 1];
if (napi_ok != napi_get_value_string_utf8(env, args[0], buffer, length + 1, &length)) {
delete[] buffer;
buffer = nullptr;
napi_throw_error(env, "-1005", "napi_get_value_string_utf8 error");
return nullptr;
}
// **********************************************************************
// ********************************MD5加密********************************
// 7、计算MD5加密操作
std::string str = buffer;
// MD5 加密计算
str = MD5(str).toStr();
// **********************************************************************
// ********************************MD5加密********************************
// 8、把C++数据转成napi_value并返回
napi_value value = nullptr;
const char* md5 = str.c_str();
if (napi_ok != napi_create_string_utf8(env, md5, strlen(md5), &value)) {
delete[] buffer;
buffer = nullptr;
napi_throw_error(env, "-1006", "napi_create_string_utf8 error");
return nullptr;
}
// 9、资源清理
delete[] buffer;
buffer = nullptr;
return value;
}
主要看第 7 步:直接创建 MD5 后调用其 toStr()
方法即可生成加密后的字符串。
增加了 MD5 计算的源码,需要修改 CMakeLists.txt 文件,目的是把计算 MD5 的源文件打包进 so 中,修改后的代码如下所示:
# the minimum version of CMake.
cmake_minimum_required(VERSION 3.4.1)
project(oh_0400_napi)
set(NATIVERENDER_ROOT_PATH ${CMAKE_CURRENT_SOURCE_DIR})
include_directories(${NATIVERENDER_ROOT_PATH}
${NATIVERENDER_ROOT_PATH}/include)
# 把 md5.cpp 源文件引入
add_library(entry SHARED hello.cpp ./md5/md5.cpp)
target_link_libraries(entry PUBLIC libace_napi.z.so)
根据 Md5() 方法的实现,限制条件是不允许数据 null 和 "",如果输入则抛异常。因此可测试以下三种场景:正常参数,null 参数和 "" 参数,样例代码如下所示:
import testNapi from 'libentry.so'
@Entry @Component struct Index {
@State message: string = 'Hello,OpenHarmony'
build() {
Column({space: 10}) {
Text(this.message)
.fontSize(20)
Button("正常参数")
.onClick(() => {
this.message = testNapi.md5("Hello, OpenHarmony")
})
Button("null参数")
.onClick(() => {
this.message = testNapi.md5(null);
})
Button("\"\"参数")
.onClick(() => {
this.message = testNapi.md5("");
})
}
.padding(10)
.width('100%')
.height("100%")
}
}
点解 正常参数 按钮,输出结果和在线网站上计算的结果一致,非常棒(#^.^#),样例运行结果如下所示:
本节笔者通过引入三方库的方式实现了 MD5 的计算,当前只是一个简单的计算,如果是一个非常复杂的耗时计算,就会阻塞主线程,因此需要实现异步方法,笔者将要在下节讲解一下异步的实现方式。
如果你觉得这篇内容对你还蛮有帮助,我想邀请你帮我三个小忙:
原创声明:本文系作者授权腾讯云开发者社区发表,未经许可,不得转载。
如有侵权,请联系 cloudcommunity@tencent.com 删除。
原创声明:本文系作者授权腾讯云开发者社区发表,未经许可,不得转载。
如有侵权,请联系 cloudcommunity@tencent.com 删除。