通过TSS软件栈使用TPM——获取并改变TPM寄存器-学习笔记1

实验使用TPM_Emulator代替TPM硬件，原理是一样的。（学习网站：http://blog.csdn.net/buaa_shang/article/details/26157253）

1.登录系统后通过命令启动TPM模拟器：

sudo modprobe tpmd_dev

sudo tpmd -f -d clear

2.启动TrouSerS软件栈

sudo tcsd -e -f

//另外可创建一个文件夹，里面新建一个.c文件，可用vim编辑器编写，保存后，用gcc工具对.c文件进行编译，然后执行即可。

shm@shm-Junyi-M580:~$ mkdir myFiles
shm@shm-Junyi-M580:~$ cd myFiles/
shm@shm-Junyi-M580:~/myFiles$ vim tpm1.c

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/types.h>

#include <tss/tss_error.h>
#include <tss/platform.h>
#include <tss/tss_defines.h>
#include <tss/tss_typedef.h>
#include <tss/tss_structs.h>
#include <tss/tspi.h>
#include <trousers/trousers.h>

#define Debug(message, tResult) printf("%s : %s\n", message, (char *)Trspi_Error_String(result))
void printMenu();

int main(int argc, char **argv)
{
    TSS_HCONTEXT     hContext;
    TSS_HTPM        hTPM;
    TSS_HPCRS        hPcrs;
    TSS_HENCDATA    hEncData;
    TSS_HENCDATA    hRetrieveData;
    TSS_RESULT         result;
    TSS_HKEY         hSRK = 0;
    TSS_HPOLICY        hSRKPolicy = 0;
    TSS_UUID        SRK_UUID = TSS_UUID_SRK;

    BYTE             wks[20];
    BYTE             *pubKey;
    UINT32            pubKeySize;
    BYTE            *rgbPcrValue;
    UINT32            ulPcrLen;
    BYTE            *encData;
    UINT32            encDataSize;
    BYTE            *outstring;
    UINT32            outlength;
    FILE            *fout, *fin;
    int             i;
    UINT32            j;
    BYTE            valueToExtend[250];
    int             count = 0;
    int             pcrToExtend = 0;
    

    memset(wks, 0, 20);
    memset(valueToExtend, 0, 250);

    //Pick the TPM you are talking to. 
    //In this case, it is the system TPM(indicated with NULL)
    result = Tspi_Context_Create(&hContext);
    Debug("Create Context", result);

    result = Tspi_Context_Connect(hContext, NULL);
    Debug("Context Connect", result);

    //Get the TPM handle
    result = Tspi_Context_GetTpmObject(hContext, &hTPM);
    Debug("Get TPM Handle", result);

    //Get the SRK handle
    result = Tspi_Context_LoadKeyByUUID(hContext, TSS_PS_TYPE_SYSTEM, SRK_UUID, &hSRK);
    Debug("Get the SRK handle", result);

    //Get the SRK policy
    result = Tspi_GetPolicyObject(hSRK, TSS_POLICY_USAGE, &hSRKPolicy);
    Debug("Get the SRK policy", result);

    //Then set the SRK policy to be the well known secret
    result = Tspi_Policy_SetSecret(hSRKPolicy, TSS_SECRET_MODE_SHA1, 20, wks);


    //输出所有PCR寄存器内的值
    /*********************/
    for (j = 0; j < 24; j++)
    {
        result = Tspi_TPM_PcrRead(hTPM, j, &ulPcrLen, &rgbPcrValue);
        printf("PCR %02d ", j);
        for (i = 0; i < 19; i++)
            printf("%02x", *(rgbPcrValue + i));
        printf("\n");
    }
    /*********************/
    
    //Display each command line argument.
    printf("\n Command line arguments:\n");
    for (count = 0; count <argc; count++)
        printf("argv[%d] : %s\n", count, argv[count]);
    
    //Examine command line arguments.
    if (argc >= 3)
    {
        if (strcmp(argv[1],"-p") == 0)
        {
            pcrToExtend = atoi(argv[2]);
            if (pcrToExtend < 0 || pcrToExtend > 23)
            {
                printMenu();
                return 0;
            }
        }

        if (argc == 5)
        {
            if (strcmp(argv[3], "-v") == 0)
                memcpy(valueToExtend, argv[4], strlen(argv[4]));
        }
        else    //Use default value.
        {
            memcpy(valueToExtend, "abcdefghijklmnopqrst", 20);
        }
    }
    else
    {
        printMenu();
        return 0;
    }

    //Extend the value
    result = Tspi_TPM_PcrExtend(hTPM, pcrToExtend, 20, (BYTE *)valueToExtend, NULL, &ulPcrLen, &rgbPcrValue);
    Debug("Extended the PCR", result);

    //输出所有PCR寄存器内的值
    /*********************/
    for (j = 0; j < 24; j++)
    {
        result = Tspi_TPM_PcrRead(hTPM, j, &ulPcrLen, &rgbPcrValue);
        printf("PCR %02d ", j);
        for (i = 0; i < 19; i++)
            printf("%02x", *(rgbPcrValue + i));
        printf("\n");
    }
    /*********************/
    

    //Clean up
    Tspi_Context_FreeMemory(hContext, NULL);
    Tspi_Context_Close(hContext);
    
    return 0;
}

void printMenu()
{
    printf("\nChangePCRn Help Menu:\n");
    printf("\t -p PCR regiter to extend(0-23)\n");
    printf("\t -v Value to be extended into PCR(abc...)\n");
    printf("\t Note: -v argument is optional and a default value will be used if no value is provided\n");
    printf("\t Example: ChangePCRn -p 10 -v abcdef\n");
}

shm@shm-Junyi-M580:~/myFiles$ ls -al
总用量 12
drwxrwxr-x  2 shm shm 4096 10月 23 20:43 .
drwxr-xr-x 40 shm shm 4096 10月 23 20:43 ..
-rw-rw-r--  1 shm shm 3608 10月 23 20:43 tpm1.c
shm@shm-Junyi-M580:~/myFiles$ gcc tpm1.c -o tpm1 -ltspi
shm@shm-Junyi-M580:~/myFiles$ ./tpm1 -p 0    

//注：通过-p选项指定要修改的PCR寄存器的序号（此处为PCR0，只是为了演示，PCR0用来存放可信启动过程中的度量值）

//下图为程序输出的没有修改前PCR寄存器内值的情况：

Create Context : Success
Context Connect : Success
Get TPM Handle : Success
Get the SRK handle : Success
Get the SRK policy : Success
PCR 00 00000000000000000000000000000000000000
PCR 01 00000000000000000000000000000000000000
PCR 02 00000000000000000000000000000000000000
PCR 03 00000000000000000000000000000000000000
PCR 04 00000000000000000000000000000000000000
PCR 05 00000000000000000000000000000000000000
PCR 06 00000000000000000000000000000000000000
PCR 07 00000000000000000000000000000000000000
PCR 08 00000000000000000000000000000000000000
PCR 09 00000000000000000000000000000000000000
PCR 10 00000000000000000000000000000000000000
PCR 11 00000000000000000000000000000000000000
PCR 12 00000000000000000000000000000000000000
PCR 13 00000000000000000000000000000000000000
PCR 14 00000000000000000000000000000000000000
PCR 15 00000000000000000000000000000000000000
PCR 16 ffffffffffffffffffffffffffffffffffffff
PCR 17 ffffffffffffffffffffffffffffffffffffff
PCR 18 ffffffffffffffffffffffffffffffffffffff
PCR 19 ffffffffffffffffffffffffffffffffffffff
PCR 20 ffffffffffffffffffffffffffffffffffffff
PCR 21 ffffffffffffffffffffffffffffffffffffff
PCR 22 ffffffffffffffffffffffffffffffffffffff
PCR 23 ffffffffffffffffffffffffffffffffffffff
//修改成功后的PCR值输出：  可见PCR0中160bit值被修改了。（通过PCR_Extend操作后所有PCR寄存器内值的情况：
 Command line arguments:
argv[0] : ./tpm1
argv[1] : -p
argv[2] : 0
Extended the PCR : Success
PCR 00 30b94d3d773fe9349dba938c5ced5981b95220
PCR 01 00000000000000000000000000000000000000
PCR 02 00000000000000000000000000000000000000
PCR 03 00000000000000000000000000000000000000
PCR 04 00000000000000000000000000000000000000
PCR 05 00000000000000000000000000000000000000
PCR 06 00000000000000000000000000000000000000
PCR 07 00000000000000000000000000000000000000
PCR 08 00000000000000000000000000000000000000
PCR 09 00000000000000000000000000000000000000
PCR 10 00000000000000000000000000000000000000
PCR 11 00000000000000000000000000000000000000
PCR 12 00000000000000000000000000000000000000
PCR 13 00000000000000000000000000000000000000
PCR 14 00000000000000000000000000000000000000
PCR 15 00000000000000000000000000000000000000
PCR 16 ffffffffffffffffffffffffffffffffffffff
PCR 17 ffffffffffffffffffffffffffffffffffffff
PCR 18 ffffffffffffffffffffffffffffffffffffff
PCR 19 ffffffffffffffffffffffffffffffffffffff
PCR 20 ffffffffffffffffffffffffffffffffffffff
PCR 21 ffffffffffffffffffffffffffffffffffffff
PCR 22 ffffffffffffffffffffffffffffffffffffff
PCR 23 ffffffffffffffffffffffffffffffffffffff
shm@shm-Junyi-M580:~/myFiles$