在LoadRunner中进行Base64的编码和解码

《Base64 Encode/Decode for LoadRunner》这篇文章介绍了如何在LoadRunner中对字符串进行Base64的编码和解码：

http://ptfrontline.wordpress.com/2009/09/30/base64-encodedecode-for-loadrunner/

在头文件中封装b64_encode_string和b64_decode_string函数：

/*
Base 64 Encode and Decode functions for LoadRunner
==================================================
This include file provides functions to Encode and Decode
LoadRunner variables. It's based on source codes found on the
internet and has been modified to work in LoadRunner.

Created by Kim Sandell / Celarius - www.celarius.com
*/
// Encoding lookup table
char base64encode_lut[] = {
'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q',
'R','S','T','U','V','W','X','Y','Z','a','b','c','d','e','f','g','h',
'i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y',
'z','0','1','2','3','4','5','6','7','8','9','+','/','='};

// Decode lookup table
char base64decode_lut[] = {
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, 0,62, 0, 0, 0,63,52,53,54,55,56,57,58,59,60,61, 0, 0,
0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,
15,16,17,18,19,20,21,22,23,24,25, 0, 0, 0, 0, 0, 0,26,27,28,
29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,
49,50,51, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, };

void base64encode(char *src, char *dest, int len)
// Encodes a buffer to base64
{
int i=0, slen=strlen(src);
for(i=0;i<slen && i<len;i+=3,src+=3)
{ // Enc next 4 characters
*(dest++)=base64encode_lut[(*src&0xFC)>>0x2];
*(dest++)=base64encode_lut[(*src&0x3)<<0x4|(*(src+1)&0xF0)>>0x4];
*(dest++)=((i+1)<slen)?base64encode_lut[(*(src+1)&0xF)<<0x2|(*(src+2)&0xC0)>>0x6]:'=';
*(dest++)=((i+2)<slen)?base64encode_lut[*(src+2)&0x3F]:'=';
}
*dest='/0'; // Append terminator
}

void base64decode(char *src, char *dest, int len)
// Encodes a buffer to base64
{
int i=0, slen=strlen(src);
for(i=0;i<slen&&i<len;i+=4,src+=4)
{ // Store next 4 chars in vars for faster access
char c1=base64decode_lut[*src], c2=base64decode_lut[*(src+1)], c3=base64decode_lut[*(src+2)], c4=base64decode_lut[*(src+3)];
// Decode to 3 chars
*(dest++)=(c1&0x3F)<<0x2|(c2&0x30)>>0x4;
*(dest++)=(c3!=64)?((c2&0xF)<<0x4|(c3&0x3C)>>0x2):'/0';
*(dest++)=(c4!=64)?((c3&0x3)<<0x6|c4&0x3F):'/0';
}
*dest='/0'; // Append terminator
}

int b64_encode_string( char *source, char *lrvar )
// ----------------------------------------------------------------------------
// Encodes a string to base64 format
//
// Parameters:
//        source    Pointer to source string to encode
//        lrvar     LR variable where base64 encoded string is stored
//
// Example:
//
//        b64_encode_string( "Encode Me!", "b64" )
// ----------------------------------------------------------------------------
{
int dest_size;
int res;
char *dest;
// Allocate dest buffer
dest_size = 1 + ((strlen(source)+2)/3*4);
dest = (char *)malloc(dest_size);
memset(dest,0,dest_size);
// Encode & Save
base64encode(source, dest, dest_size);
lr_save_string( dest, lrvar );
// Free dest buffer
res = strlen(dest);
free(dest);
// Return length of dest string
return res;
}

int b64_decode_string( char *source, char *lrvar )
// ----------------------------------------------------------------------------
// Decodes a base64 string to plaintext
//
// Parameters:
//        source    Pointer to source base64 encoded string
//        lrvar     LR variable where decoded string is stored
//
// Example:
//
//        b64_decode_string( lr_eval_string("{b64}"), "Plain" )
// ----------------------------------------------------------------------------
{
int dest_size;
int res;
char *dest;
// Allocate dest buffer
dest_size = strlen(source);
dest = (char *)malloc(dest_size);
memset(dest,0,dest_size);
// Encode & Save
base64decode(source, dest, dest_size);
lr_save_string( dest, lrvar );
// Free dest buffer
res = strlen(dest);
free(dest);
// Return length of dest string
return res;
}

使用的例子如下所示：

#include "base64.h"

vuser_init()
{
int res;

// ENCODE
lr_save_string("ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789","plain");
b64_encode_string( lr_eval_string("{plain}"), "b64str" );
lr_output_message("Encoded: %s", lr_eval_string("{b64str}") );

// DECODE
b64_decode_string( lr_eval_string("{b64str}"), "plain2" );
lr_output_message("Decoded: %s", lr_eval_string("{plain2}") );

// Verify decoded matches original plain text
res = strcmp( lr_eval_string("{plain}"), lr_eval_string("{plain2}") );
if (res==0) lr_output_message("Decoded matches original plain text");

return 0;

}