/*
 * COPYRIGHT (c) International Business Machines Corp. 2005-2017
 *
 * This program is provided under the terms of the Common Public License,
 * version 1.0 (CPL-1.0). Any use, reproduction or distribution for this
 * software constitutes recipient's acceptance of CPL-1.0 terms which can be
 * found in the file LICENSE file or at
 * https://opensource.org/licenses/cpl1.0.php
 */

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

#include <openssl/rsa.h>

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

#include <trousers/trousers.h>

#include "pkcs11types.h"
#include "stdll.h"
#include "defs.h"
#include "host_defs.h"
#include "h_extern.h"
#include "trace.h"

#include "tpm_specific.h"

static const struct {
    TSS_FLAG mode;
    const char *str;
} tss_modes[] = {
    {TSS_SECRET_MODE_NONE, "TSS_SECRET_MODE_NONE"},
    {TSS_SECRET_MODE_SHA1, "TSS_SECRET_MODE_SHA1"},
    {TSS_SECRET_MODE_PLAIN, "TSS_SECRET_MODE_PLAIN"},
    {TSS_SECRET_MODE_POPUP, "TSS_SECRET_MODE_POPUP"},
    {TSS_SECRET_MODE_CALLBACK, "TSS_SECRET_MODE_CALLBACK"},
};

UINT32 util_get_keysize_flag(CK_ULONG size)
{
    switch (size) {
    case 512:
        return TSS_KEY_SIZE_512;
        break;
    case 1024:
        return TSS_KEY_SIZE_1024;
        break;
    case 2048:
        return TSS_KEY_SIZE_2048;
        break;
    default:
        break;
    }

    return 0;
}

CK_BYTE *util_create_id(int type)
{
    CK_BYTE *ret = NULL;
    int size = 0;

    switch (type) {
    case TPMTOK_PRIVATE_ROOT_KEY:
        size = TPMTOK_PRIVATE_ROOT_KEY_ID_SIZE + 1;
        if ((ret = malloc(size)) == NULL) {
            TRACE_ERROR("malloc of %d bytes failed.", size);
            break;
        }

        sprintf((char *) ret, "%s", TPMTOK_PRIVATE_ROOT_KEY_ID);
        break;
    case TPMTOK_PUBLIC_ROOT_KEY:
        size = TPMTOK_PUBLIC_ROOT_KEY_ID_SIZE + 1;
        if ((ret = malloc(size)) == NULL) {
            TRACE_ERROR("malloc of %d bytes failed.", size);
            break;
        }

        sprintf((char *) ret, "%s", TPMTOK_PUBLIC_ROOT_KEY_ID);
        break;
    case TPMTOK_PUBLIC_LEAF_KEY:
        size = TPMTOK_PUBLIC_LEAF_KEY_ID_SIZE + 1;
        if ((ret = malloc(size)) == NULL) {
            TRACE_ERROR("malloc of %d bytes failed.", size);
            break;
        }

        sprintf((char *) ret, "%s", TPMTOK_PUBLIC_LEAF_KEY_ID);
        break;
    case TPMTOK_PRIVATE_LEAF_KEY:
        size = TPMTOK_PRIVATE_LEAF_KEY_ID_SIZE + 1;
        if ((ret = malloc(size)) == NULL) {
            TRACE_ERROR("malloc of %d bytes failed.", size);
            break;
        }

        sprintf((char *) ret, "%s", TPMTOK_PRIVATE_LEAF_KEY_ID);
        break;
    default:
        TRACE_ERROR("Unknown type: %d\n", type);
        break;
    }

    return ret;
}

int util_set_file_mode(char *filename, mode_t mode)
{
    struct stat file_stat;

    if (stat(filename, &file_stat) == -1) {
        TRACE_ERROR("stat failed: %s\n", strerror(errno));
        return -1;
    } else if ((file_stat.st_mode ^ mode) != 0) {
        if (chmod(filename, mode) == -1) {
            TRACE_ERROR("chmod(%s) failed: %s\n", filename, strerror(errno));
            return -1;
        }
    }

    return 0;
}

/* make sure the public exponent attribute is 65537 */
CK_ULONG util_check_public_exponent(TEMPLATE * tmpl)
{
    CK_RV rv;
    CK_ATTRIBUTE *publ_exp_attr;
    CK_BYTE pubexp_bytes[] = { 1, 0, 1 };
    CK_ULONG publ_exp, rc = 1;

    rv = template_attribute_get_non_empty(tmpl, CKA_PUBLIC_EXPONENT,
                                          &publ_exp_attr);
    if (rv != CKR_OK) {
        TRACE_ERROR("Couldn't find public exponent attribute.\n");
        return rv;
    }

    switch (publ_exp_attr->ulValueLen) {
    case 3:
        rc = memcmp(pubexp_bytes, publ_exp_attr->pValue, 3);
        break;
    case sizeof(CK_ULONG):
        publ_exp = *((CK_ULONG *) publ_exp_attr->pValue);
        if (publ_exp == 65537)
            rc = 0;
        break;
    default:
        break;
    }

    return rc;
}

TSS_RESULT util_set_public_modulus(TSS_HCONTEXT tspContext, TSS_HKEY hKey,
                                   unsigned long size_n, unsigned char *n)
{
    UINT64 offset;
    UINT32 blob_size;
    BYTE *blob, pub_blob[1024];
    TCPA_PUBKEY pub_key;
    TSS_RESULT result;

    /* Get the TCPA_PUBKEY blob from the key object. */
    result =
        Tspi_GetAttribData(hKey, TSS_TSPATTRIB_KEY_BLOB,
                           TSS_TSPATTRIB_KEYBLOB_PUBLIC_KEY, &blob_size, &blob);
    if (result != TSS_SUCCESS) {
        TRACE_ERROR("Tspi_GetAttribData failed: rc=0x%x", result);
        return result;
    }

    offset = 0;
    result = Trspi_UnloadBlob_PUBKEY(&offset, blob, &pub_key);
    if (result != TSS_SUCCESS) {
        TRACE_ERROR("Tspi_GetAttribData failed: rc=0x%x", result);
        return result;
    }

    Tspi_Context_FreeMemory(tspContext, blob);
    /* Free the first dangling reference, putting 'n' in its place */
    free(pub_key.pubKey.key);
    pub_key.pubKey.keyLength = size_n;
    pub_key.pubKey.key = n;

    offset = 0;
    Trspi_LoadBlob_PUBKEY(&offset, pub_blob, &pub_key);

    /* Free the second dangling reference */
    free(pub_key.algorithmParms.parms);

    /* set the public key data in the TSS object */
    result =
        Tspi_SetAttribData(hKey, TSS_TSPATTRIB_KEY_BLOB,
                           TSS_TSPATTRIB_KEYBLOB_PUBLIC_KEY, (UINT32) offset,
                           pub_blob);
    if (result != TSS_SUCCESS) {
        TRACE_ERROR("Tspi_SetAttribData failed: rc=0x%x", result);
        return result;
    }

    return TSS_SUCCESS;
}

TSS_FLAG get_srk_mode(void)
{
    char *mode = NULL;
    int i;
    int num_modes = sizeof(tss_modes) / sizeof(tss_modes[0]);

    mode = getenv("OCK_SRK_MODE");
    if (mode == NULL)
        return 0;

    /* parse */
    for (i = 0; i < num_modes; i++) {
        if (strncmp(mode, tss_modes[i].str, strlen(mode)) == 0)
            return tss_modes[i].mode;
    }

    TRACE_ERROR("Unknown TSS mode set in OCK_SRK_MODE, %s.\n", mode);
    return -1;
}

int get_srk_info(struct srk_info *srk)
{
    char *passwd_ptr = NULL;
    char *secret = NULL;
    int i;

    srk->mode = get_srk_mode();
    if (srk->mode == -1)
        return -1;

    srk->secret = NULL;
    passwd_ptr = getenv("OCK_SRK_SECRET");

    /* If nothing is set, then use original opencryptoki default of
     *  secret is NULL and TSS_SECRET_MODE_PLAIN.
     */
    if (passwd_ptr == NULL) {
        srk->len = 0;
        if (srk->mode == 0) {
            srk->mode = TSS_SECRET_MODE_PLAIN;
            return 0;
        }
    } else {
        srk->len = strlen(passwd_ptr);
    }

    /* A mode required at this point...  */
    if (srk->mode == 0) {
        TRACE_ERROR("SRK policy's secret mode is not set.\n");
        return -1;
    }

    /*
     * getenv() returns a ptr to the actual string in our env,
     * so be sure to make a copy to avoid problems.
     */

    if (srk->len != 0) {
        if ((secret = (char *) malloc(srk->len + 1)) == NULL) {
            TRACE_ERROR("malloc of %d bytes failed.\n", srk->len);
            return -1;
        }
        memcpy(secret, passwd_ptr, srk->len);
        secret[srk->len] = '\0';
        srk->secret = secret;
    }

    /* Secrets that are a hash, need to be converted from a
     *  hex string to an array of bytes.
     */
    if (srk->mode == TSS_SECRET_MODE_SHA1) {

        char *secret_h;
        int h_len = TPM_SHA1_160_HASH_LEN;

        if ((secret_h = (char *) malloc(h_len)) == NULL) {
            TRACE_ERROR("malloc of %d bytes failed.\n", h_len);
            goto error;
        }

        /* reuse passwd ptr since we dont need it anymore. */
        passwd_ptr = secret;

        /* Assume hash is read in as string of hexidecimal digits.
         * 2 hex digits are required to represent a byte.
         * thus we need 2 * TPM_SHA1_160_HASH_LEN to
         * represent the hash.
         */
        if (srk->len != (h_len * 2)) {
            free(secret_h);
            TRACE_DEVEL("Hashed secret is %d bytes, expected %d.\n",
                        srk->len, h_len * 2);
            goto error;
        }

        /* convert hexadecimal string into a byte array... */
        for (i = 0; i < h_len; i++) {
            sscanf(passwd_ptr, "%2hhx", (unsigned char *)&secret_h[i]);
            passwd_ptr += 2;
        }

        srk->len = h_len;
        srk->secret = secret_h;
        free(secret);
    }

    return 0;

error:
    if (secret)
        free(secret);

    return -1;
}
