libtpms/src/tpm2/LibtpmsCallbacks.c

// SPDX-License-Identifier: BSD-2-Clause

// (c) Copyright IBM Corporation 2018.

#include <stdint.h>
#include <string.h>

#include "Platform.h"
#include "LibtpmsCallbacks.h"
#include "NVMarshal.h"

#define TPM_HAVE_TPM2_DECLARATIONS
#include "tpm_library_intern.h"
#include "tpm_error.h"
#include "tpm_nvfilename.h"

int libtpms_plat__NVEnable(void)
{
    unsigned char*            data   = NULL;
    uint32_t                  length = 0;
    struct libtpms_callbacks* cbs    = TPMLIB_GetCallbacks();
    TPM_RC                    rc;
    bool                      is_empty_state;

    /* try to get state blob set via TPMLIB_SetState() */
    GetCachedState(TPMLIB_STATE_PERMANENT, &data, &length, &is_empty_state);
    if(is_empty_state)
    {
        memset(s_NV, 0, NV_MEMORY_SIZE);
        return 0;
    }

    if(data == NULL && cbs->tpm_nvram_loaddata)
    {
        uint32_t    tpm_number = 0;
        const char* name       = TPM_PERMANENT_ALL_NAME;
        TPM_RESULT  ret;

        ret = cbs->tpm_nvram_loaddata(&data, &length, tpm_number, name);
        switch(ret)
        {
            case TPM_RETRY:
                if(!cbs->tpm_nvram_storedata)
                {
                    return -1;
                }
                memset(s_NV, 0, NV_MEMORY_SIZE);
                return 0;

            case TPM_SUCCESS:
                /* got the data -- unmarshal them... */
                break;

            case TPM_FAIL:
            default:
                return -1;
        }
    }

    if(data)
    {
        unsigned char* buffer = data;
        INT32          size   = length;

        rc                    = PERSISTENT_ALL_Unmarshal(&buffer, &size);
        free(data);
        if(rc != TPM_RC_SUCCESS)
            return -1;
        return 0;
    }
    return LIBTPMS_CALLBACK_FALLTHROUGH; /* -2 */
}

int libtpms_plat__NVDisable(void)
{
    struct libtpms_callbacks* cbs = TPMLIB_GetCallbacks();

    if(cbs->tpm_nvram_loaddata)
        return 0;
    return LIBTPMS_CALLBACK_FALLTHROUGH; /* -2 */
}

int libtpms_plat__IsNvAvailable(void)
{
    struct libtpms_callbacks* cbs = TPMLIB_GetCallbacks();

    if(cbs->tpm_nvram_loaddata && cbs->tpm_nvram_storedata)
    {
        return 1;
    }
    return LIBTPMS_CALLBACK_FALLTHROUGH; /* -2 */
}

int libtpms_plat__NvCommit(void)
{
    struct libtpms_callbacks* cbs = TPMLIB_GetCallbacks();

    if(cbs->tpm_nvram_storedata)
    {
        uint32_t    tpm_number = 0;
        const char* name       = TPM_PERMANENT_ALL_NAME;
        TPM_RESULT  ret;
        BYTE*       buf;
        uint32_t    buflen;

        ret = TPM2_PersistentAllStore(&buf, &buflen);
        if(ret != TPM_SUCCESS)
            return ret;

        ret = cbs->tpm_nvram_storedata(buf, buflen, tpm_number, name);
        free(buf);
        if(ret == TPM_SUCCESS)
            return 0;

        return -1;
    }
    return LIBTPMS_CALLBACK_FALLTHROUGH; /* -2 */
}

int libtpms_plat__PhysicalPresenceAsserted(BOOL* pp)
{
    struct libtpms_callbacks* cbs = TPMLIB_GetCallbacks();

    if(cbs->tpm_io_getphysicalpresence)
    {
        uint32_t      tpm_number = 0;
        TPM_RESULT    res;
        unsigned char mypp;

        res = cbs->tpm_io_getphysicalpresence(&mypp, tpm_number);
        if(res == TPM_SUCCESS)
        {
            *pp = mypp;
            return 0;
        }
    }
    return LIBTPMS_CALLBACK_FALLTHROUGH;
}