Step to UEFI (61） —– SHA-1的实现

前面介绍了 MD5 的实现，这里介绍一下 SHA-1 算法的实现。具体代码来自【参考1】。

和之前 MD5 程序有一些差别在于这个程序不是一次性将所有文件都放入内存中，而是放入一部分，计算一部分，再用中间结果继续计算下一部分。这样，再大的文件也可以正常处理。

#include  <Uefi.h>
#include  <Library/UefiLib.h>
#include  <Library/ShellCEntryLib.h>

#include  <stdio.h>
#include  <stdlib.h>
#include  <wchar.h>

#include <Protocol/EfiShell.h>
#include <Library/ShellLib.h>
#include <Library/MemoryAllocationLib.h>

#include "sha1.h"

#define BUFFERSIZE 2048

extern EFI_BOOT_SERVICES         *gBS;
extern EFI_SYSTEM_TABLE			 *gST;
extern EFI_RUNTIME_SERVICES 	 *gRT;

extern EFI_SHELL_PROTOCOL        *gEfiShellProtocol;

int
EFIAPI
main (
  IN int Argc,
  IN CHAR16 **Argv
  )
{
  EFI_FILE_HANDLE   FileHandle;
  RETURN_STATUS     Status;
  EFI_FILE_INFO     *FileInfo = NULL;
  EFI_HANDLE        *HandleBuffer=NULL;
  UINTN  			ReadSize=BUFFERSIZE;
  SHA1Context 		sha;
  
  //Check if there is a parameter
  if (Argc == 1) {
	Print(L"Usage: crctest [filename]\n");
	return 0;
  }
  
  //Open the file given by the parameter
  Status = ShellOpenFileByName(Argv[1], (SHELL_FILE_HANDLE *)&FileHandle,
                               EFI_FILE_MODE_READ , 0);

  if(Status != RETURN_SUCCESS) {
        Print(L"OpenFile failed!\n");
		return EFI_SUCCESS;
      }			

  //Get file size	  
  FileInfo = ShellGetFileInfo( (SHELL_FILE_HANDLE)FileHandle);	

  /*
   *  Reset the SHA-1 context and process input
  */
  SHA1Reset(&sha);
		
  //Allocate a memory buffer
  HandleBuffer = AllocateZeroPool(BUFFERSIZE);
  if (HandleBuffer == NULL) {
      return (SHELL_OUT_OF_RESOURCES);   }

	while (BUFFERSIZE == ReadSize)		
    {
		ReadSize=BUFFERSIZE;
		//Load the whole file to the buffer
		Status = ShellReadFile(FileHandle,&ReadSize,HandleBuffer);
		SHA1Input(&sha,(unsigned char *)  HandleBuffer, ReadSize);
   } 
  
  //Output
  Print(L"File Name: %s\n",Argv[1]);
  Print(L"File Size: %d\n",(UINTN)FileInfo-> FileSize);

  if (!SHA1Result(&sha))
        {
            Print(L"sha: could not compute message digest\n");
        }
  else
        {
            Print(L"%08X %08X %08X %08X %08X\n",
                    sha.Message_Digest[0],
                    sha.Message_Digest[1],
                    sha.Message_Digest[2],
                    sha.Message_Digest[3],
                    sha.Message_Digest[4]);
        }
  
  FreePool(HandleBuffer);	
  return EFI_SUCCESS;
}

 

运行结果：

完整的代码下载：

sha1test

参考：

1.https://www.packetizer.com/