PE文件之旅

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平台 : windows XP SP1
编译器 : VC++6.0
时间 : 2004.12 -- 2005.01
参考资料: 看雪<<加密解密(第二版)>>,MengLong[DFCG]<<PE知识学习>>,<<Matt Pietrek's PE Tutorial>>.
Coded by: prince
E-mail : Cracker_prince@163.com

PE文件之旅 第一篇 Sections
PE文件之旅 第二篇 DLL的秘密 -- 输出表
PE文件之旅 第三篇 加壳与脱壳的战场 输入表
PE文件之旅 源码下载

1 PE文件之旅(C语言描述) -- 第一篇 Sections

  首先请大家直观地看一下PE文件格局。这也是PE文件存放在磁盘上的格局。



我们由IMAGE_DOS_HEADER.e_lfanew得到PE文件头在PE文件中的偏移,即IMAGE_NT_HEADERS结构,如下:
typedef struct _IMAGE_NT_HEADERS {
DWORD Signature; **PE文件标识 "PE",0,0
IMAGE_FILE_HEADER FileHeader; **映像文件头 (其中的NumberOfSections成员指定了Sections的个数)
IMAGE_OPTIONAL_HEADER32 OptionalHeader; **映像可选头
} IMAGE_NT_HEADERS32, *PIMAGE_NT_HEADERS32;

核心代码:

IMAGE_DOS_HEADER myDosHeader;
LONG e_lfanew;
FILE *pFile;
pFile = fopen("文件路径", r+cool.gif;

fread(&myDosHeader, sizeof(IMAGE_DOS_HEADER), 1, pFile); // pFile 为打开的文件指针
e_lfanew = myDosHeader.e_lfanew; // 保存PE文件头偏移

IMAGE_FILE_HEADER myFileHeader;
int nSectionCount;

fseek(pFile, (e_lfanew + sizeof(DWORD)), SEEK_SET);
fread(&myFileHeader, sizeof(IMAGE_FILE_HEADER), 1, pFile);
nSectionCount = myFileHeader.NumberOfSections; // 保存Section个数

// 过了IMAGE_NT_HEADERS结构就是IMAGE_SECTION_HEADER结构数组了,注意是结构数组,有几个Section该结构就有几个元素
// 这里动态开辟NumberOfSections个内存来存储不同的Section信息
IMAGE_SECTION_HEADER *pmySectionHeader = (IMAGE_SECTION_HEADER *)calloc(nSectionCount, sizeof(IMAGE_SECTION_HEADER));
fseek(pFile, (e_lfanew + sizeof(IMAGE_NT_HEADERS)), SEEK_SET);
fread(pmySectionHeader, sizeof(IMAGE_SECTION_HEADER), nSectionCount, pFile);

// 打印Sections信息
for (int i = 0; i < nSectionCount; i++, pmySectionHeader++)
{
printf("Name: %s/n", pmySectionHeader->Name);
printf("union_PhysicalAddress: %08x/n", pmySectionHeader->Misc.PhysicalAddress);
printf("union_VirtualSize: %04x/n", pmySectionHeader->Misc.VirtualSize);
printf("VirtualAddress: %08x/n", pmySectionHeader->VirtualAddress);
printf("SizeOfRawData: %08x/n", pmySectionHeader->SizeOfRawData);
printf("PointerToRawData: %04x/n", pmySectionHeader->PointerToRawData);
printf("PointerToRelocations: %04x/n", pmySectionHeader->PointerToRelocations);
printf("PointerToLinenumbers: %04x/n", pmySectionHeader->PointerToLinenumbers);
printf("NumberOfRelocations: %04x/n", pmySectionHeader->NumberOfRelocations);
printf("NumberOfLinenumbers: %04x/n", pmySectionHeader->NumberOfLinenumbers);
printf("Charateristics: %04x/n", pmySectionHeader->Characteristics);
}

// 恢复指针
pmySectionHeader -= m_nSectionCount;

if (pmySectionHeader != NULL) // 释放内存
{
free(pmySectionHeader);
pmySectionHeader = NULL;
}

// 最后不要忘记关闭文件
fclose(pFile);


我将以上代码改写了一个Win32程序,可以很方便地查看PE文件的Section信息。本人菜鸟,错误及不妥之处难免存在,如果大家发现有什么问题,不要吝啬啊,请告之。那么关于PE文件格式Section的C语言描述到此就结束了,下一篇将继续我们的PE文件研究,DLL的秘密 -- 输出表。

2 PE文件之旅(C语言描述) 第二篇 DLL的秘密 -- 输出表


大家好,现在继续我们的PE文件之旅第二篇, DLL的秘密 -- 输出表。
首先看一下预备知识。输出表在<<加密解密II>>等资料中并没有太多的笔墨,居我的接触,它确实比较直观,没有象输入表那样复杂的结构,所以这也可能是介绍的少的缘故。关于输出表的结构可以参考<<Matt Pietrek's PE Tutorial>>。

首先定位输出表。在IMAGE_OPTIONAL_HEADER.DataDirectory结构数组中,注意这也是个结构数组。它的每一个元素都是IMAGE_DATA_DIRECTORY结构。该结构定义如下:

typedef struct _IMAGE_DATA_DIRECTORY {
DWORD VirtualAddress;
DWORD Size;
} IMAGE_DATA_DIRECTORY, *PIMAGE_DATA_DIRECTORY;
DataDirectory结构数组的第一个元素描述的就是输出表,第二个元素描述的是输入表,呵呵,这个是我们下一篇研究对象。所以,这里的VirtualAddress就是输出表的偏移地址,Size就不用说了,输出表的大小。

注意:以下代码的一些变量在前一篇文章<<PE文件之旅 -- Sections>>中已经定义过,这里不再重新定义,请大家参考前面的文章。
核心代码:
[CODE]// 首先定位IMAGE_OPTIONAL_HEADER32结构
IMAGE_OPTIONAL_HEADER32 myOptionalHeader;
fseek(pFile, (e_lfanew + sizeof(DWORD) + sizeof(IMAGE_FILE_HEADER)), SEEK_SET); // 如此定位的原因请参考PE文件结构图
fread(&myOptionalHeader, sizeof(IMAGE_OPTIONAL_HEADER32), 1, pFile);

// 数据目录表的第一个元素为输出表
printf("输出表的偏移地址:%08x/n", myOptionalHeader.DataDirectory[0].VirtualAddress);
printf("输出表的大小:%04x/n", myOptionalHeader.DataDirectory[0].Size);

DWORD dwFileOffset;
if (myOptionalHeader.DataDirectory[0].VirtualAddress != 0)
{
// OnConvertVAToRawA()函数是进行VirtualAddress到文件偏移转换的函数,具体代码见下面
dwFileOffset = OnConvertVAToRawA(myOptionalHeader.DataDirectory[0].VirtualAddress);
if (-1 == dwFileOffset)
{
printf("输出表定位错误/n");
}
else
{
printf("输出表的文件偏移为:%08x/n", dwFileOffset);

// ------------------ 这里已经获得了输出表的文件偏移,输出表是由IED数组开始 ------------------ //
int nNumberOfFunctions = 0;
int nNumberOfNames = 0;
// 由输出表的偏移(VA)计算出文件偏移(RawAddress),然后定位到这里就是输出表了
// 输出表由IMAGE_EXPORT_DIRECTORY结构开始,
IMAGE_EXPORT_DIRECTORY *pIED = (IMAGE_EXPORT_DIRECTORY *)malloc(sizeof(IMAGE_EXPORT_DIRECTORY)); // Memory 17
fseek(pFile, dwFileOffset, SEEK_SET);
fread(pIED, sizeof(IMAGE_EXPORT_DIRECTORY), 1, pFile);

printf("IMAGE_EXPORT_DIRECTORY结构如下: /n");
printf("Characteristics:%08x(没有用途,总是为0)/n", pIED->Characteristics);
printf("TimeDateStamp:%08x(文件被产生时刻)/n", pIED->TimeDateStamp);
printf("MajorVersion:%08x(没有用途,总是为0)/n", pIED->MajorVersion);
printf("MinorVersion:%08x(没有用途,总是为0)/n", pIED->MinorVersion);
printf("Name:%08x(RVA,指向一个DLL文件名称)/n", pIED->Name);

// 读取DLL名称
char chDllName[64] = {0}; // 这里多留点空间给函数名字,防止出错,我所见过的函数名称最长也就30个char,呵呵
// 将指向DLL文件名称的VA转化为文件偏移
DWORD dwTemp = OnConvertVAToRawA(pIED->Name);
// 读取DLL文件名称
fseek(pFile, dwTemp, SEEK_SET);
fread(chDllName, 64, 1, pFile);
printf("DLL文件名称为:%s/n", chDllName);

printf("Base:%08x(起始序号)/n", pIED->Base);
// 被此模块输出的函数的起始序号
WORD wBase = (WORD)pIED->Base;

printf("NumberOfFunctions:%d(输出函数个数)/n", pIED->NumberOfFunctions);
// AddressOfFunctions 数组(稍后描述)中的元素个数。此值同时也是输出函数的个数。
// 通常这个值和 NumberOfNames 字段相同,但也可以不同。
nNumberOfFunctions = pIED->NumberOfFunctions;

printf("NumberOfNames:%d(以名称输出的函数个数)/n", pIED->NumberOfNames);
// AddressOfNames 数组(稍后描述)中的元素个数。此值表示以名称输出的函数个数。
// 通常(但不总是)和输出函数的总数相同。
nNumberOfNames = pIED->NumberOfNames;

// 这是一个 RVA (Relative Virtual Address )值,指向一个由函数地址所构成的数组。
// 我所谓的函数地址是指此一模块中的每一个输出函数的进入点的 RVA 值。
printf("AddressOfFunctions:%08x(RVA, 指向一个由函数地址构成的数组)/n", pIED->AddressOfFunctions);
// 这里将其转化为文件的偏移地址
DWORD dwAddressOfFunctions = OnConvertVAToRawA(pIED->AddressOfFunctions);

// 这是一个 RVA 值,指向一个由字符串指针所构成的数组。
// 字符串的内容是此一模块中的每一个"以名称输出的输出函数"的名称
printf("AddressOfNames:%08x(RVA, 指向一个由字符串指针所构成的数组)/n", pIED->AddressOfNames);
// 转化为文件偏移地址
DWORD dwNameAddressOfFunctions = OnConvertVAToRawA(pIED->AddressOfNames);

// 这是一个 RVA 值,指向一个 WORD 数组。
// WORD 的内容是此一模块中的每一个"以名称输出的输出函数"的序号。别忘了要加上 Base 字段中的起始序号。
printf("AddressOfNameOrdinals:%08x(RVA, 指向一个DWORD数组)/n", pIED->AddressOfNameOrdinals);
// 转化为文件偏移地址
DWORD dwAddressOfNameOrdinals = OnConvertVAToRawA(pIED->AddressOfNameOrdinals);

if (pIED != NULL) // release Memory 17
{
free(pIED);
pIED = NULL;
}

// 动态开辟内存用来存储函数的VirtualAddress
DWORD *pdwAddressOfFunctions = (DWORD *)calloc(nNumberOfFunctions, sizeof(DWORD)); // Memory 18
fseek(pFile, dwAddressOfFunctions, SEEK_SET);
fread(pdwAddressOfFunctions, sizeof(DWORD), nNumberOfFunctions, pFile);
// 动态开辟内存用来存储函数的RawAddress
DWORD *pRowAddressOfFunctions = (DWORD *)calloc(nNumberOfFunctions, sizeof(DWORD)); // Memory 19
for (int i = 0; i < nNumberOfFunctions; i++, pdwAddressOfFunctions++, pRowAddressOfFunctions++)
{
*pRowAddressOfFunctions = OnConvertVAToRAwA(*pdwAddressOfFunctions);
}
// 恢复指针
pdwAddressOfFunctions -= nNumberOfFunctions;
pRowAddressOfFunctions -= nNumberOfFunctions;

// 动态开辟内存用来存储函数名称地址
DWORD *pdwNameAddressOfFunctions = (DWORD *)calloc(nNumberOfNames, sizeof(DWORD)); // Memory 20
fseek(pFile, dwNameAddressOfFunctions, SEEK_SET);
fread(pdwNameAddressOfFunctions, sizeof(DWORD), nNumberOfNames, pFile);
// VA TO RAWA
for (i = 0; i < nNumberOfNames; i++, pdwNameAddressOfFunctions++)
{
*pdwNameAddressOfFunctions = OnConvertVAToRowA(*pdwNameAddressOfFunctions);
}
// 恢复指针
pdwNameAddressOfFunctions -= nNumberOfNames;

// 二重指针,用来存储函数名称指针,因为函数个数不固定
DWORD **pFunctionsName = (DWORD **)calloc(nNumberOfNames, sizeof(char *)); // Memory 21
for (i = 0; i < nNumberOfNames; i++, pFunctionsName++)
{
// 这块内存是用来存放函数名称的
char *pchFunctionName = (char *)malloc(sizeof(char) * 64);
*pFunctionsName = (DWORD *)pchFunctionName;
}
// 恢复指针
pFunctionsName -= nNumberOfNames;

// 读出函数名称
for (i = 0; i < nNumberOfNames; i++, pdwNameAddressOfFunctions++, pFunctionsName++)
{
fseek(pFile, *pdwNameAddressOfFunctions, SEEK_SET);
fread(*pFunctionsName, 64, 1, pFile);
}
// 恢复指针
pdwNameAddressOfFunctions -= nNumberOfNames;
pFunctionsName -= nNumberOfNames;

if (pdwNameAddressOfFunctions != NULL) // release Memory 20
{
free(pdwNameAddressOfFunctions);
pdwNameAddressOfFunctions = NULL;
}

// 读出函数的序号
WORD *pwFunctionsOrdinals = (WORD *)calloc(nNumberOfNames, sizeof(WORD)); // Memory 22
fseek(pFile, dwAddressOfNameOrdinals, SEEK_SET);
for (i = 0; i < nNumberOfNames; i++, pwFunctionsOrdinals++)
{
fread(pwFunctionsOrdinals, sizeof(WORD), 1, pFile);
}
// 恢复指针
pwFunctionsOrdinals -= nNumberOfNames;

// 这里需要注意的是AddressOfFunctions所指的数组。这是一个DWORD数组,每一个DWORD都是
// 一个输出函数的RVA地址。每一个输出函数的序号都与函数在此数组中的位置一致。假使起始序号
// 为1,那么输出序号为1者其函数地址在此数组中排在第一个位置。输出序号为2者其函数地址在此
// 函数地址中则排在第二个位置,依次类推。

// 由以上可知,我们必须对AddressOfNameOrdinals所指向的WORD数组进行升序排序,同时进行的还有
// 函数名称存放位置的排序,因为Ordinals和函数名称存放的位置是对应的。

// 这里采用效率较高的快速排序(详细代码见下面)
QuickSort(pwFunctionsOrdinals, pFunctionsName, nNumberOfNames);

// 打印信息
for (i = 0; i < nNumberOfNames; i++, pwFunctionsOrdinals++, pFunctionsName++, pRowAddressOfFunctions++, pdwAddressOfFunctions++)
{
printf("Ordinals: %04x/n", *pwFunctionsOrdinals + wBase);
printf("函数%d: %s/n", i + 1, *pFunctionsName);
printf("RowAddress: %08x/n", *pRowAddressOfFunctions);
printf("VirtulAddress: %08x/n", *pdwAddressOfFunctions);
}

// 恢复指针
pwFunctionsOrdinals -= nNumberOfNames;
pFunctionsName -= nNumberOfNames;
pRowAddressOfFunctions -= nNumberOfNames;
pdwAddressOfFunctions -= nNumberOfNames;

if (pdwAddressOfFunctions != NULL) // release Memory 18
{
free(pdwAddressOfFunctions);
pdwAddressOfFunctions = NULL;
}

if (pRowAddressOfFunctions != NULL) // release Memory 19
{
free(pRowAddressOfFunctions);
pRowAddressOfFunctions = NULL;
}

for (i = 0; i < nNumberOfNames; i++, pFunctionsName++) // release Memory 21
{
if (*pFunctionsName != NULL)
{
free(*pFunctionsName);
*pFunctionsName = NULL;
}
}
pFunctionsName -= nNumberOfNames;

if (pFunctionsName != NULL) // release prince 21
{
free(pFunctionsName);
pFunctionsName = NULL;
}

if (pwFunctionsOrdinals != NULL) // release prince 22
{
free(pwFunctionsOrdinals);
pwFunctionsOrdinals = NULL;
}
}
}
else
{
printf("此文件无输出表/n");
}


// VA到RAWA的转换程序(原理请参考<<加密解密II>>中关于输出表的部分)
DWORD OnConvertVAToRawA(DWORD dwFileOffset)
{
IMAGE_SECTION_HEADER *pmySectionHeader = (IMAGE_SECTION_HEADER *)calloc(nSectionCount, sizeof(IMAGE_SECTION_HEADER)); // prince 14
fseek(pFile, (e_lfanew + 4 + sizeof(IMAGE_FILE_HEADER) + sizeof(IMAGE_OPTIONAL_HEADER32)), SEEK_SET);
fread(pmySectionHeader, sizeof(IMAGE_SECTION_HEADER), nSectionCount, pFile);

DWORD dwFilePos;
DWORD dwOffset;
DWORD *pdwVA = (DWORD *)malloc(sizeof(DWORD) * nSectionCount); // prince 15
DWORD *pdwRowA = (DWORD *)malloc(sizeof(DWORD) * nSectionCount); // prince 16
for (int i = 0; i < nSectionCount; i++, pmySectionHeader++, pdwVA++, pdwRowA++)
{
*pdwVA = pmySectionHeader->VirtualAddress;
*pdwRowA = pmySectionHeader->PointerToRawData;
}

pmySectionHeader -= nSectionCount;

pdwVA -= nSectionCount;
pdwRowA -= nSectionCount;

for (i = 0; i < nSectionCount; i++, pdwVA++, pdwRowA++)
{
if ((dwFileOffset >= *pdwVA) && (dwFileOffset < *(pdwVA + 1)))
{
dwOffset = *pdwVA - *pdwRowA;
dwFilePos = dwFileOffset - dwOffset;

pdwVA -= i;
pdwRowA -= i;
if (pdwVA != NULL) // release prince 15
{
free(pdwVA);
pdwVA = NULL;
}
if (pdwRowA != NULL) // release prince 16
{
free(pdwRowA);
pdwRowA = NULL;
}

if (pmySectionHeader != NULL) // release prince 14
{
free(pmySectionHeader);
pmySectionHeader = NULL;
}

return dwFilePos;
}
}
pdwVA -= nSectionCount;
pdwRowA -= nSectionCount;

if (pmySectionHeader != NULL) // release prince 14
{
free(pmySectionHeader);
pmySectionHeader = NULL;
}

if (pdwVA != NULL) // release prince 15
{
free(pdwVA);
pdwVA = NULL;
}

if (pdwRowA != NULL) // release prince 16
{
free(pdwRowA);
pdwRowA = NULL;
}

return -1;
}

void QuickSort(WORD *pwSourceData1, DWORD **pdwSourceData2, int nNumberOfArray)
{
SortRun(pwSourceData1, pdwSourceData2, 0, nNumberOfArray - 1);
}

void SortRun(WORD *pwSourceData1, DWORD **pdwSourceData2, int nLeft, int nRight)
{
WORD wMiddle, wTemp;
DWORD *pdwTemp;
int i, j;

wMiddle = pwSourceData1[(nLeft + nRight) / 2];
i = nLeft;
j = nRight;

while (i < j)
{
while ((pwSourceData1[i] < wMiddle) && (i < j))
{
i++;
}
while ((pwSourceData1[j] > wMiddle) && (j > i))
{
j--;
}

if (i <= j)
{
wTemp = pwSourceData1[i];
pwSourceData1[i] = pwSourceData1[j];
pwSourceData1[j] = wTemp;

pdwTemp = *(pdwSourceData2 + i);
*(pdwSourceData2 + i) = *(pdwSourceData2 + j);
*(pdwSourceData2 + j) = pdwTemp;

i++;
j--;
}
}

// 如果左边还有元素,对左边进行快速排序
if (nLeft < j)
{
SortRun(pwSourceData1, pdwSourceData2, 0, j);
}

// 如果右边还有元素,对右边进行快速排序
if (nRight > i)
{
SortRun(pwSourceData1, pdwSourceData2, i, nRight);
}
}

呼~,好累啊!也感谢你坚持看完。接下来的一篇就是大家最关心,也是最重要的输出表了,敬请关注下一篇:PE文件之旅 -- 加壳与脱壳的战场 输入表。

3 PE文件之旅 -- 第三篇 加壳与脱壳的战场 输入表(俯源码)


PE文件之旅(C语言描述) 第三篇 -- 加壳与脱壳的战场 输出表

呼~,终于到输入表了,No Wasting Time, Let's Go!
还是讲原理先。输入表较前一篇的输出表稍微复杂一些,所谓复杂,在C语言里,无非就是多了

几重指针,通过多重指针找啊找的才能访问到想要的东西。就好象你拿着钱找绑匪(T),到了T指定的地点

,接了个电话,T又指定了一个新的地点,于是你到了T指定的新的地点... 呵呵,开个玩笑。上一篇我们

在IMAGE_OPTIONAL_HEADER32.DataDirectory的第一个数组里面找到了输出表,第二个元素描述的就是输

入表的信息。大家还记得这个DataDirectory结构数组吧?它是IMAGE_DATA_DIRECTORY结构,有必要再重

申一下它的定义:

typedef struct _IMAGE_DATA_DIRECTORY {
DWORD VirtualAddress;
DWORD Size;
} IMAGE_DATA_DIRECTORY, *PIMAGE_DATA_DIRECTORY;
想起来了吧,ViretualAddress就指向输出表(接到绑匪电话了,呵呵)。还等什么?我们开始吧!

核心代码:

// 首先定位IMAGE_OPTIONAL_HEADER32结构
IMAGE_OPTIONAL_HEADER32 myOptionalHeader;
fseek(pFile, (e_lfanew + sizeof(DWORD) + sizeof(IMAGE_FILE_HEADER)), SEEK_SET); // 如此

定位的原因请参考PE文件结构图
fread(&myOptionalHeader, sizeof(IMAGE_OPTIONAL_HEADER32), 1, pFile);

// 将输入表的VA转换为文件偏移
dwFileOffset = OnConvertVAToRawA(myOptionalHeader.DataDirectory[1].VirtualAddress);
if (dwFileOffset != -1)
{
printf("输入表的文件偏移为:%08x/n", dwFileOffset);
// 输入表由IMAGE_IMPORT_DESCRIPTOR结构数组开始,每一个被隐式调用的DLL文件都会有一个

对应的IID结构数组
// 但是没有字段指明IID数组的个数,也就是引入的DLL文件个数,但是这个IID数组的最后一个

元素全为0,
// 通过这一点可以计算出引入的DLL文件的个数,也就是IID结构数组的元素个数。
// IMAGE_IMPORT_DESCRIPTOR结构定义:
// typedef struct _IMAGE_IMPORT_DESCRIPTOR {
// union {
// DWORD Characteristics; // 0 for terminating null import

descriptor
// DWORD OriginalFirstThunk; // RVA to original unbound IAT

(PIMAGE_THUNK_DATA)
// };
// DWORD TimeDateStamp; // 0 if not bound,
// -1 if bound, and real date/time stamp
// in IMAGE_DIRECTORY_ENTRY_BOUND_IMPORT

(new BIND)
// O.W. date/time stamp of DLL bound to

(Old BIND)

// DWORD ForwarderChain; // -1 if no forwarders
// DWORD Name;
// DWORD FirstThunk; // RVA to IAT (if bound this IAT has

actual addresses)
// } IMAGE_IMPORT_DESCRIPTOR;
// 现在已经获得了输入表的文件偏移,所以从这里开始就是输入表的IID数组了
IMAGE_IMPORT_DESCRIPTOR IID;
fseek(pFile, dwFileOffset, SEEK_SET);
fread(&IID, sizeof(IMAGE_IMPORT_DESCRIPTOR), 1, pFile);
// 得到IID数组个数先
int nDllCount = 0;
while ((0 != IID.Characteristics) || (0 != IID.FirstThunk) || (0 !=

IID.ForwarderChain) || (0 != IID.Name) || (0 != IID.OriginalFirstThunk) || (0 !=

IID.TimeDateStamp) )
{
nDllCount++;
fread(&IID, sizeof(IMAGE_IMPORT_DESCRIPTOR), 1, pFile);
}
printf("导入的DLL个数为:%d/n", nDllCount);

// 已经得到了导入的DLL个数,现在把他们读出来
IMAGE_IMPORT_DESCRIPTOR *pIID = (IMAGE_IMPORT_DESCRIPTOR *)calloc(nDllCount, sizeof

(IMAGE_IMPORT_DESCRIPTOR)); // prince 01
fseek(pFile, dwFileOffset, SEEK_SET);
fread(pIID, sizeof(IMAGE_IMPORT_DESCRIPTOR), nDllCount, pFile);

// IID.Name中存放的就是DLL文件的名称的地址,注意是地址而不是以Zero结尾的字符串.
// --------------------- 通过IID.Name的RVA读出DLL的名称 ----------------------- //
DWORD *pNameFileOffset = (DWORD *)malloc(sizeof(DWORD) * nDllCount); // prince 02
// 取出这些Name的VA转化为FileOffset存在pNamefileOffset中
for (int i = 0; i < nDllCount; i++, pNameFileOffset++, pIID++)
{
*pNameFileOffset = OnConvertVAToRowA(pIID->Name);
}
// 恢复指针
pIID -= nDllCount;
pNameFileOffset -= nDllCount;

// 动态开辟指针数组pName,*pName指向存着DLL Name的pchName
DWORD *pName = (DWORD *)calloc(nDllCount, sizeof(DWORD)); // prince 03 必须和04一起

释放
for (i = 0; i < nDllCount; i++, pName++)
{
// 每次开辟一个chName[16]用于存放Name
char *pchName = (char *)malloc(sizeof(char) * 16); // prince 04 必须和03

一起释放
// 将本次申请的内存的地址保存到*pName中
*pName = (DWORD)pchName;
}
// 恢复指针
pName -= nDllCount;
// 以上动态分配内存的部分实际上是二重指针,这里这样分配好理解一些,下面再遇见同样的

问题就直接声明多重指针了
// 读取Name
for (i = 0; i < nDllCount; i++, pNameFileOffset++, pName++)
{
DWORD dwDllName = *pNameFileOffset;
fseek(pFile, dwDllName, SEEK_SET);
char chTemp[16] = {0};
fread((void *)*pName, 16, 1, pFile);
}
pNameFileOffset -= nDllCount;
pName -= nDllCount;

if (pNameFileOffset != NULL) // release prince 02
{
free(pNameFileOffset);
pNameFileOffset = NULL;
}
// --------------- pName中就是每个DLL文件名称的文件偏移地址 ------------------- //

// 读取IMAGE_IMPORT_DESCRIPTOR的OriginalFirstThunk(或Characteristics)的值,该值指向

IMAGE_THUNK_DATA结构数组,
// IMAGE_THUNK_DATA数组的每一个指针都指向IMAGE_IMPORT_BY_NAME结构
// 动态开辟空间用来保存每个DLL的FistThunk值(文件偏移值)
DWORD *pFirstThunkOfFileOffset = (DWORD *)calloc(nDllCount, sizeof(DWORD)); //

prince 05
char *pbByIndex = (char *)calloc(nDllCount, sizeof(char)); //

prince 06
for (i = 0; i < nDllCount; i++, pbByIndex++)
{
*pbByIndex = 0;
}
pbByIndex -= nDllCount; // 用来判断是否函数引入的标志

// 读出OriginalFirstThunk所指向的值,该值高位的两个字节如果是0x8000,则说明该函数是

以序号引入。
// 低位的两个字节即为引入序号,比如该值为:0x80001234,那么就说明引入的是该DLL文件的

第1234h号函数。
DWORD *pdwRowAddressOfOriginalFirstThunk = (DWORD *)malloc(sizeof(DWORD)); //

prince 23
for (i = 0; i < nDllCount; i++, pIID++, pFirstThunkOfFileOffset++, pbByIndex++)
{
DWORD dwTemp = OnConvertVAToRawA(pIID->OriginalFirstThunk);
fseek(pFile, dwTemp, SEEK_SET);
fread(pdwRowAddressOfOriginalFirstThunk, sizeof(DWORD), 1, pFile);
if (0 != *pdwRowAddressOfOriginalFirstThunk)
{
struct HightBit
{
int nHightBit : 1;
}Bit;
Bit.nHightBit = *pdwRowAddressOfOriginalFirstThunk >> 31;
if (0 != Bit.nHightBit) // 按序号引入函数
{
*pbByIndex = 1;
*pFirstThunkOfFileOffset = OnConvertVAToRawA(pIID-

>OriginalFirstThunk);
}
else // 按名称引入函数
{
*pFirstThunkOfFileOffset = OnConvertVAToRawA(pIID-

>OriginalFirstThunk);
}
}
else
{
*pFirstThunkOfFileOffset = OnConvertVAToRawA(pIID->FirstThunk);
}
}
// 恢复指针
pIID -= nDllCount;
pFirstThunkOfFileOffset -= nDllCount;
pbByIndex -= nDllCount;

if (pdwRowAddressOfOriginalFirstThunk != NULL) // release prince 23
{
free(pdwRowAddressOfOriginalFirstThunk);
pdwRowAddressOfOriginalFirstThunk = NULL;
}

if (pIID != NULL) // release prince 01
{
free(pIID);
pIID = NULL;
}

// -------------------- pFirstThunkOfFileOffset中是每个DLL入口的文件偏移值 --------

----------- //

// 同样,IMAGE_THUNK_DATA结构数组也是以全0作为结束,用这一点来计算出每个DLL文件的函

数个数
// --------------------------------- 读取每个DLL的函数的个数 ----------------------

---------- //
int *pnFunctionCountPerDll = (int *)calloc(nDllCount, sizeof(int));

// prince 07
IMAGE_THUNK_DATA *pITD = (IMAGE_THUNK_DATA *)malloc(sizeof(IMAGE_THUNK_DATA));

// prince 08
for (i = 0; i < nDllCount; i++, pnFunctionCountPerDll++, pFirstThunkOfFileOffset++)
{
fseek(pFile, *pFirstThunkOfFileOffset, SEEK_SET);
fread(pITD, sizeof(IMAGE_THUNK_DATA), 1, pFile);
int nFunctionCount = 0;
while ((pITD->u1.ForwarderString != 0) || (pITD->u1.Function != 0) || (pITD

->u1.Ordinal != 0) || (pITD->u1.AddressOfData != 0))
{
nFunctionCount++;
fread(pITD, sizeof(IMAGE_THUNK_DATA), 1, pFile);
}
*pnFunctionCountPerDll = nFunctionCount;
}
if (pITD != NULL) // release prince 08
{
free(pITD);
pITD = NULL;
}

pFirstThunkOfFileOffset -= nDllCount;
pnFunctionCountPerDll -= nDllCount;
// ---------------- pnFunctionCountPerDll中存放的就是每个DLL中引入的函数个数 ------

---------- //

// 由于DLL文件的个数,每个DLL文件的函数个数都是不固定的,所以这里我用了三重指针。
// 也许用了三重指针使下面的程序难懂了一些,但是我认为这是最好的方法了。
// ------------------------------ 读取每个DLL文件中函数的名称 ---------------------

---------- //
DWORD ***pdwFunctionOfDll = (DWORD ***)calloc(nDllCount, sizeof(DWORD**));

// prince 09 必须和10,11一起释放
for (i = 0; i < nDllCount; i++, pdwFunctionOfDll++, pnFunctionCountPerDll++)
{
DWORD **pdwFileOffsetOfFunction = (DWORD **)calloc(*pnFunctionCountPerDll,

sizeof(char*)); // prince 10 必须和09,11一起释放
*pdwFunctionOfDll = pdwFileOffsetOfFunction;
for (int j = 0; j < *pnFunctionCountPerDll; j++, pdwFileOffsetOfFunction++)
{
char *pchFunctionName = (char *)malloc(sizeof(char) * 64);

// prince 11 必须和09,10一起释放
*pdwFileOffsetOfFunction = (DWORD *)pchFunctionName;
}
}
pdwFunctionOfDll -= nDllCount;
pnFunctionCountPerDll -= nDllCount;

// ----------------------- 确定哪几个DLL文件是序号引入 ----------------------------

//
int nByIndexDllCount = 0;
for (i = 0; i < nDllCount; i++, pbByIndex++)
{
if (0 != *pbByIndex)
{
nByIndexDllCount++;
}
}
pbByIndex -= nDllCount;
// ----------------------- 有nByIndexDllCount个DLL文件是由序号引入的 --------------

----- //

// ----------------------- 再求出每个由序号引入的DLL的函数个数 --------------------

-- //
int *pnByIndexDllFunctionsCount = (int *)calloc(nByIndexDllCount, sizeof(int));

// prince 24
for (i = 0; i < nDllCount; i++, pbByIndex++, pnFunctionCountPerDll++)
{
if (0 != *pbByIndex)
{
*pnByIndexDllFunctionsCount = *pnFunctionCountPerDll;
pnByIndexDllFunctionsCount++;
}
}
pbByIndex -= nDllCount;
pnFunctionCountPerDll -= nDllCount;
pnByIndexDllFunctionsCount -= nByIndexDllCount;
// ------------------- pnByIndexDllFunctionsCount所指向的就是每个由序号引入的DLL文件

的函数个数 ---------------- //

// ------------------ 动态开辟内存用来保存由序号引入的函数序号 --------------------

---- //
DWORD **pdwFunctionIndex = (DWORD **)calloc(nByIndexDllCount, sizeof(DWORD *));

// prince 25
for (i = 0; i < nByIndexDllCount; i++, pnByIndexDllFunctionsCount++,

pdwFunctionIndex++)
{
DWORD *pdwFunctionIndexTmp = (DWORD *)calloc(*pnByIndexDllFunctionsCount,

sizeof(DWORD)); // prince 26
*pdwFunctionIndex = pdwFunctionIndexTmp;
}
pnByIndexDllFunctionsCount -= nByIndexDllCount;
pdwFunctionIndex -= nByIndexDllCount;
// --------------------------------------------------------------------------------

------//

for (i = 0; i < nDllCount; i++, pFirstThunkOfFileOffset++, pnFunctionCountPerDll++,

pdwFunctionOfDll++, pbByIndex++)
{
IMAGE_THUNK_DATA *pITD = (IMAGE_THUNK_DATA *)calloc(*pnFunctionCountPerDll,

sizeof(IMAGE_THUNK_DATA)); // prince 12
fseek(pFile, *pFirstThunkOfFileOffset, SEEK_SET);
fread(pITD, sizeof(IMAGE_THUNK_DATA), *pnFunctionCountPerDll, pFile);
DWORD dwFileOffsetOfFunction;
if (0 == *pbByIndex)
{
for (int j = 0; j < *pnFunctionCountPerDll; j++, pITD++)
{
dwFileOffsetOfFunction = OnConvertVAToRowA((DWORD)pITD-

>u1.AddressOfData);
fseek(pFile, dwFileOffsetOfFunction + 2, SEEK_SET);
fread((void *)**pdwFunctionOfDll, 64, 1, pFile);
strText.Format("%s", **pdwFunctionOfDll);
(*pdwFunctionOfDll)++;
}
pITD -= *pnFunctionCountPerDll;
*pdwFunctionOfDll -= *pnFunctionCountPerDll;
}
else
{
for (int j = 0; j < *pnByIndexDllFunctionsCount; j++, pITD++,

(*pdwFunctionIndex)++)
{
**pdwFunctionIndex = (DWORD)pITD->u1.AddressOfData;
}
pITD -= *pnByIndexDllFunctionsCount;
*pdwFunctionIndex -= *pnByIndexDllFunctionsCount;
pnByIndexDllFunctionsCount++;
pdwFunctionIndex++;
}

if (pITD != NULL) // release prince 12
{
free(pITD);
pITD = NULL;
}

}

if (nByIndexDllCount != 0)
{
pnByIndexDllFunctionsCount -= nByIndexDllCount;
pdwFunctionIndex -= nByIndexDllCount;
}

pdwFunctionOfDll -= nDllCount;
pFirstThunkOfFileOffset -= nDllCount;
pnFunctionCountPerDll -= nDllCount;
pbByIndex -= nDllCount;

if (pFirstThunkOfFileOffset != NULL) // release prince 05
{
free(pFirstThunkOfFileOffset);
pFirstThunkOfFileOffset = NULL;
}
// -------------------------- 三重指针pdwFunctionOfDll最终指向函数名称 ------------

---------------- //

// --------------------- 处理由序号引入的函数的序号 --------------------------------

//


for (i = 0; i < nDllCount; i++, pName++, pnFunctionCountPerDll++,

pdwFunctionOfDll++, pbByIndex++)
{
prince("DLL %d 名字:%s/n", (i + 1), *pName);
prince("调用函数个数:%d/n", *pnFunctionCountPerDll);
if (0 == *pbByIndex)
{
for (int j = 0; j < *pnFunctionCountPerDll; j++,

(*pdwFunctionOfDll)++)
{
prince("%s/n", **pdwFunctionOfDll);
}
*pdwFunctionOfDll -= *pnFunctionCountPerDll;
}
else
{
prince("此DLL文件中函数由序号引入!");
for (int j = 0; j < *pnByIndexDllFunctionsCount; j++,

(*pdwFunctionIndex)++)
{
prince("引入序号: %04x/n", ((**pdwFunctionIndex) & 0xffff));

// 取0x80000000的后两个字节
m_ListBox1.AddString(strText);
}
*pdwFunctionIndex -= *pnByIndexDllFunctionsCount;
pnByIndexDllFunctionsCount++;
pdwFunctionIndex++;
}

}

// 恢复指针
pName -= nDllCount;
pnFunctionCountPerDll -= nDllCount;
pdwFunctionOfDll -= nDllCount;
pbByIndex -= nDllCount;

pnByIndexDllFunctionsCount -= nByIndexDllCount;
pdwFunctionIndex -= nByIndexDllCount;

for (i = 0; i < nDllCount; i++, pName++) // release prince 04
{
if (*pName != NULL)
{
free((void *)*pName);
*pName = NULL;
}
}
pName -= nDllCount;
if (pName != NULL) // release prince 03
{
free(pName);
pName = NULL;
}

if (pbByIndex != NULL) // release prince 06
{
free(pbByIndex);
pbByIndex = NULL;
}

for (i = 0; i < nDllCount; i++, pdwFunctionOfDll++, pnFunctionCountPerDll++) //

release prince 11
{
for (int j = 0; j < *pnFunctionCountPerDll; j++, (*pdwFunctionOfDll)++)
{
if (**pdwFunctionOfDll != NULL)
{
free((void *)**pdwFunctionOfDll);
**pdwFunctionOfDll = NULL;
}
}
*pdwFunctionOfDll -= *pnFunctionCountPerDll;
}
pnFunctionCountPerDll -= nDllCount;
pdwFunctionOfDll -= nDllCount;

for (i = 0; i < nDllCount; i++, pdwFunctionOfDll++) // release prince 10
{
if (*pdwFunctionOfDll != NULL)
{
free(*pdwFunctionOfDll);
*pdwFunctionOfDll = NULL;
}
}
pdwFunctionOfDll -= nDllCount;

if (pdwFunctionOfDll != NULL) // release prince 09
{
free(pdwFunctionOfDll);
pdwFunctionOfDll = NULL;
}


if (pnFunctionCountPerDll != NULL) //

release prince 07
{
free(pnFunctionCountPerDll);
pnFunctionCountPerDll = NULL;
}

if (pnByIndexDllFunctionsCount != NULL) // release prince 24
{
free(pnByIndexDllFunctionsCount);
pnByIndexDllFunctionsCount = NULL;
}

for (i = 0; i < nByIndexDllCount; i++, pdwFunctionIndex++) // release prince 26
{
if (*pdwFunctionIndex != NULL)
{
free(*pdwFunctionIndex);
*pdwFunctionIndex = NULL;
}
}
pdwFunctionIndex -= nByIndexDllCount;

if (pdwFunctionIndex != NULL) // release prince 25
{
free(pdwFunctionIndex);
pdwFunctionIndex = NULL;
}
}
else
{
printf("输入表定位错误!");
}


// 计算VA到文件偏移的子程序
DWORD OnConvertVAToRawA(DWORD dwFileOffset)
{
IMAGE_SECTION_HEADER *pmySectionHeader = (IMAGE_SECTION_HEADER *)calloc

(m_nSectionCount, sizeof(IMAGE_SECTION_HEADER)); // prince 14
fseek(pFile, (e_lfanew + 4 + sizeof(IMAGE_FILE_HEADER) + sizeof

(IMAGE_OPTIONAL_HEADER32)), SEEK_SET);
fread(pmySectionHeader, sizeof(IMAGE_SECTION_HEADER), m_nSectionCount, pFile);

DWORD dwFilePos;
DWORD dwOffset;
DWORD *pdwVA = (DWORD *)malloc(sizeof(DWORD) * m_nSectionCount); // prince 15
DWORD *pdwRowA = (DWORD *)malloc(sizeof(DWORD) * m_nSectionCount); // prince 16
for (int i = 0; i < m_nSectionCount; i++, pmySectionHeader++, pdwVA++, pdwRowA++)
{
*pdwVA = pmySectionHeader->VirtualAddress;
*pdwRowA = pmySectionHeader->PointerToRawData;
}

pmySectionHeader -= m_nSectionCount;

pdwVA -= m_nSectionCount;
pdwRowA -= m_nSectionCount;

for (i = 0; i < m_nSectionCount; i++, pdwVA++, pdwRowA++)
{
if ((dwFileOffset >= *pdwVA) && (dwFileOffset < *(pdwVA + 1)))
{
dwOffset = *pdwVA - *pdwRowA;
dwFilePos = dwFileOffset - dwOffset;

pdwVA -= i;
pdwRowA -= i;
if (pdwVA != NULL) // release prince 15
{
free(pdwVA);
pdwVA = NULL;
}
if (pdwRowA != NULL) // release prince 16
{
free(pdwRowA);
pdwRowA = NULL;
}

if (pmySectionHeader != NULL) // release prince 14
{
free(pmySectionHeader);
pmySectionHeader = NULL;
}

return dwFilePos;
}
}
pdwVA -= m_nSectionCount;
pdwRowA -= m_nSectionCount;

if (pmySectionHeader != NULL) // release prince 14
{
free(pmySectionHeader);
pmySectionHeader = NULL;
}

if (pdwVA != NULL) // release prince 15
{
free(pdwVA);
pdwVA = NULL;
}

if (pdwRowA != NULL) // release prince 16
{
free(pdwRowA);
pdwRowA = NULL;
}

return -1;
}

PE文件之旅全部系列到此就告一段落了。在将近一个月的时间里通过对PE文件格式的研究让我从

正向的角度全面的了解了EXE文件执行的有关细节,同时对我自己而言也是得到了锻炼和提高,无奈编程

水平有限,这篇堆砌起来的垃圾代码还有着严重的不雅和缺陷,希望高手看了之后能腾出宝贵的时间对我

指点一二;同时也希望对我有着很大帮助和提高的这几篇小小的心得能让广大和我一样渴求知识和追求软

件技术的小菜们得到自己真正想要的东西。
还是那句老话,抛砖引玉,我是就着<<PE知识学习>>写下去的。接下去我会继续研究PE文件的资

源,看看资源的压缩原理,也就是压缩壳的原理,等有了成果再和大家分享。在这里希望大家在学习知识 
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