// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2010 IBM Corporation
 * Copyright (c) 2019-2021, Linaro Limited
 *
 * See Documentation/security/keys/trusted-encrypted.rst
 */

#include <crypto/hash_info.h>
#include <crypto/sha1.h>
#include <crypto/utils.h>
#include <linux/hex.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/parser.h>
#include <linux/string.h>
#include <linux/err.h>
#include <keys/trusted-type.h>
#include <linux/key-type.h>
#include <linux/tpm.h>
#include <linux/tpm_command.h>

#include <keys/trusted_tpm.h>

static struct tpm_chip *chip;
static struct tpm_digest *digests;

/* implementation specific TPM constants */
#define TPM_SIZE_OFFSET                 2
#define TPM_RETURN_OFFSET               6
#define TPM_DATA_OFFSET                 10

#define LOAD32(buffer, offset)  (ntohl(*(uint32_t *)&buffer[offset]))
#define LOAD32N(buffer, offset) (*(uint32_t *)&buffer[offset])
#define LOAD16(buffer, offset)  (ntohs(*(uint16_t *)&buffer[offset]))

struct osapsess {
        uint32_t handle;
        unsigned char secret[SHA1_DIGEST_SIZE];
        unsigned char enonce[TPM_NONCE_SIZE];
};

/* discrete values, but have to store in uint16_t for TPM use */
enum {
        SEAL_keytype = 1,
        SRK_keytype = 4
};

#define TPM_DEBUG 0

#if TPM_DEBUG
static inline void dump_options(struct trusted_key_options *o)
{
        pr_info("sealing key type %d\n", o->keytype);
        pr_info("sealing key handle %0X\n", o->keyhandle);
        pr_info("pcrlock %d\n", o->pcrlock);
        pr_info("pcrinfo %d\n", o->pcrinfo_len);
        print_hex_dump(KERN_INFO, "pcrinfo ", DUMP_PREFIX_NONE,
                       16, 1, o->pcrinfo, o->pcrinfo_len, 0);
}

static inline void dump_sess(struct osapsess *s)
{
        print_hex_dump(KERN_INFO, "trusted-key: handle ", DUMP_PREFIX_NONE,
                       16, 1, &s->handle, 4, 0);
        pr_info("secret:\n");
        print_hex_dump(KERN_INFO, "", DUMP_PREFIX_NONE,
                       16, 1, &s->secret, SHA1_DIGEST_SIZE, 0);
        pr_info("trusted-key: enonce:\n");
        print_hex_dump(KERN_INFO, "", DUMP_PREFIX_NONE,
                       16, 1, &s->enonce, SHA1_DIGEST_SIZE, 0);
}

static inline void dump_tpm_buf(unsigned char *buf)
{
        int len;

        pr_info("\ntpm buffer\n");
        len = LOAD32(buf, TPM_SIZE_OFFSET);
        print_hex_dump(KERN_INFO, "", DUMP_PREFIX_NONE, 16, 1, buf, len, 0);
}
#else
static inline void dump_options(struct trusted_key_options *o)
{
}

static inline void dump_sess(struct osapsess *s)
{
}

static inline void dump_tpm_buf(unsigned char *buf)
{
}
#endif

static int TSS_rawhmac(unsigned char *digest, const unsigned char *key,
                       unsigned int keylen, ...)
{
        struct hmac_sha1_ctx hmac_ctx;
        va_list argp;
        unsigned int dlen;
        unsigned char *data;
        int ret = 0;

        hmac_sha1_init_usingrawkey(&hmac_ctx, key, keylen);

        va_start(argp, keylen);
        for (;;) {
                dlen = va_arg(argp, unsigned int);
                if (dlen == 0)
                        break;
                data = va_arg(argp, unsigned char *);
                if (data == NULL) {
                        ret = -EINVAL;
                        break;
                }
                hmac_sha1_update(&hmac_ctx, data, dlen);
        }
        va_end(argp);
        if (!ret)
                hmac_sha1_final(&hmac_ctx, digest);
        return ret;
}

/*
 * calculate authorization info fields to send to TPM
 */
static int TSS_authhmac(unsigned char *digest, const unsigned char *key,
                        unsigned int keylen, unsigned char *h1,
                        unsigned char *h2, unsigned int h3, ...)
{
        unsigned char paramdigest[SHA1_DIGEST_SIZE];
        struct sha1_ctx sha_ctx;
        unsigned int dlen;
        unsigned char *data;
        unsigned char c;
        int ret = 0;
        va_list argp;

        if (!chip)
                return -ENODEV;

        c = !!h3;
        sha1_init(&sha_ctx);
        va_start(argp, h3);
        for (;;) {
                dlen = va_arg(argp, unsigned int);
                if (dlen == 0)
                        break;
                data = va_arg(argp, unsigned char *);
                if (!data) {
                        ret = -EINVAL;
                        break;
                }
                sha1_update(&sha_ctx, data, dlen);
        }
        va_end(argp);
        if (!ret)
                sha1_final(&sha_ctx, paramdigest);
        if (!ret)
                ret = TSS_rawhmac(digest, key, keylen, SHA1_DIGEST_SIZE,
                                  paramdigest, TPM_NONCE_SIZE, h1,
                                  TPM_NONCE_SIZE, h2, 1, &c, 0, 0);
        return ret;
}

/*
 * verify the AUTH1_COMMAND (Seal) result from TPM
 */
static int TSS_checkhmac1(unsigned char *buffer,
                          const uint32_t command,
                          const unsigned char *ononce,
                          const unsigned char *key,
                          unsigned int keylen, ...)
{
        uint32_t bufsize;
        uint16_t tag;
        uint32_t ordinal;
        uint32_t result;
        unsigned char *enonce;
        unsigned char *continueflag;
        unsigned char *authdata;
        unsigned char testhmac[SHA1_DIGEST_SIZE];
        unsigned char paramdigest[SHA1_DIGEST_SIZE];
        struct sha1_ctx sha_ctx;
        unsigned int dlen;
        unsigned int dpos;
        va_list argp;
        int ret;

        if (!chip)
                return -ENODEV;

        bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
        tag = LOAD16(buffer, 0);
        ordinal = command;
        result = LOAD32N(buffer, TPM_RETURN_OFFSET);
        if (tag == TPM_TAG_RSP_COMMAND)
                return 0;
        if (tag != TPM_TAG_RSP_AUTH1_COMMAND)
                return -EINVAL;
        authdata = buffer + bufsize - SHA1_DIGEST_SIZE;
        continueflag = authdata - 1;
        enonce = continueflag - TPM_NONCE_SIZE;

        sha1_init(&sha_ctx);
        sha1_update(&sha_ctx, (const u8 *)&result, sizeof(result));
        sha1_update(&sha_ctx, (const u8 *)&ordinal, sizeof(ordinal));
        va_start(argp, keylen);
        for (;;) {
                dlen = va_arg(argp, unsigned int);
                if (dlen == 0)
                        break;
                dpos = va_arg(argp, unsigned int);
                sha1_update(&sha_ctx, buffer + dpos, dlen);
        }
        va_end(argp);
        sha1_final(&sha_ctx, paramdigest);

        ret = TSS_rawhmac(testhmac, key, keylen, SHA1_DIGEST_SIZE, paramdigest,
                          TPM_NONCE_SIZE, enonce, TPM_NONCE_SIZE, ononce,
                          1, continueflag, 0, 0);
        if (ret < 0)
                return ret;

        if (crypto_memneq(testhmac, authdata, SHA1_DIGEST_SIZE))
                return -EINVAL;
        return 0;
}

/*
 * verify the AUTH2_COMMAND (unseal) result from TPM
 */
static int TSS_checkhmac2(unsigned char *buffer,
                          const uint32_t command,
                          const unsigned char *ononce,
                          const unsigned char *key1,
                          unsigned int keylen1,
                          const unsigned char *key2,
                          unsigned int keylen2, ...)
{
        uint32_t bufsize;
        uint16_t tag;
        uint32_t ordinal;
        uint32_t result;
        unsigned char *enonce1;
        unsigned char *continueflag1;
        unsigned char *authdata1;
        unsigned char *enonce2;
        unsigned char *continueflag2;
        unsigned char *authdata2;
        unsigned char testhmac1[SHA1_DIGEST_SIZE];
        unsigned char testhmac2[SHA1_DIGEST_SIZE];
        unsigned char paramdigest[SHA1_DIGEST_SIZE];
        struct sha1_ctx sha_ctx;
        unsigned int dlen;
        unsigned int dpos;
        va_list argp;
        int ret;

        bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
        tag = LOAD16(buffer, 0);
        ordinal = command;
        result = LOAD32N(buffer, TPM_RETURN_OFFSET);

        if (tag == TPM_TAG_RSP_COMMAND)
                return 0;
        if (tag != TPM_TAG_RSP_AUTH2_COMMAND)
                return -EINVAL;
        authdata1 = buffer + bufsize - (SHA1_DIGEST_SIZE + 1
                        + SHA1_DIGEST_SIZE + SHA1_DIGEST_SIZE);
        authdata2 = buffer + bufsize - (SHA1_DIGEST_SIZE);
        continueflag1 = authdata1 - 1;
        continueflag2 = authdata2 - 1;
        enonce1 = continueflag1 - TPM_NONCE_SIZE;
        enonce2 = continueflag2 - TPM_NONCE_SIZE;

        sha1_init(&sha_ctx);
        sha1_update(&sha_ctx, (const u8 *)&result, sizeof(result));
        sha1_update(&sha_ctx, (const u8 *)&ordinal, sizeof(ordinal));

        va_start(argp, keylen2);
        for (;;) {
                dlen = va_arg(argp, unsigned int);
                if (dlen == 0)
                        break;
                dpos = va_arg(argp, unsigned int);
                sha1_update(&sha_ctx, buffer + dpos, dlen);
        }
        va_end(argp);
        sha1_final(&sha_ctx, paramdigest);

        ret = TSS_rawhmac(testhmac1, key1, keylen1, SHA1_DIGEST_SIZE,
                          paramdigest, TPM_NONCE_SIZE, enonce1,
                          TPM_NONCE_SIZE, ononce, 1, continueflag1, 0, 0);
        if (ret < 0)
                return ret;
        if (crypto_memneq(testhmac1, authdata1, SHA1_DIGEST_SIZE))
                return -EINVAL;
        ret = TSS_rawhmac(testhmac2, key2, keylen2, SHA1_DIGEST_SIZE,
                          paramdigest, TPM_NONCE_SIZE, enonce2,
                          TPM_NONCE_SIZE, ononce, 1, continueflag2, 0, 0);
        if (ret < 0)
                return ret;
        if (crypto_memneq(testhmac2, authdata2, SHA1_DIGEST_SIZE))
                return -EINVAL;
        return 0;
}

/*
 * For key specific tpm requests, we will generate and send our
 * own TPM command packets using the drivers send function.
 */
static int trusted_tpm_send(unsigned char *cmd, size_t buflen)
{
        struct tpm_buf buf;
        int rc;

        if (!chip)
                return -ENODEV;

        rc = tpm_try_get_ops(chip);
        if (rc)
                return rc;

        buf.flags = 0;
        buf.length = buflen;
        buf.data = cmd;
        dump_tpm_buf(cmd);
        rc = tpm_transmit_cmd(chip, &buf, 4, "sending data");
        dump_tpm_buf(cmd);

        if (rc > 0)
                /* TPM error */
                rc = -EPERM;

        tpm_put_ops(chip);
        return rc;
}

/*
 * Lock a trusted key, by extending a selected PCR.
 *
 * Prevents a trusted key that is sealed to PCRs from being accessed.
 * This uses the tpm driver's extend function.
 */
static int pcrlock(const int pcrnum)
{
        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;

        return tpm_pcr_extend(chip, pcrnum, digests) ? -EINVAL : 0;
}

/*
 * Create an object specific authorisation protocol (OSAP) session
 */
static int osap(struct tpm_buf *tb, struct osapsess *s,
                const unsigned char *key, uint16_t type, uint32_t handle)
{
        unsigned char enonce[TPM_NONCE_SIZE];
        unsigned char ononce[TPM_NONCE_SIZE];
        int ret;

        ret = tpm_get_random(chip, ononce, TPM_NONCE_SIZE);
        if (ret < 0)
                return ret;

        if (ret != TPM_NONCE_SIZE)
                return -EIO;

        tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_OSAP);
        tpm_buf_append_u16(tb, type);
        tpm_buf_append_u32(tb, handle);
        tpm_buf_append(tb, ononce, TPM_NONCE_SIZE);

        ret = trusted_tpm_send(tb->data, tb->length);
        if (ret < 0)
                return ret;

        s->handle = LOAD32(tb->data, TPM_DATA_OFFSET);
        memcpy(s->enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]),
               TPM_NONCE_SIZE);
        memcpy(enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) +
                                  TPM_NONCE_SIZE]), TPM_NONCE_SIZE);
        return TSS_rawhmac(s->secret, key, SHA1_DIGEST_SIZE, TPM_NONCE_SIZE,
                           enonce, TPM_NONCE_SIZE, ononce, 0, 0);
}

/*
 * Create an object independent authorisation protocol (oiap) session
 */
static int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce)
{
        int ret;

        if (!chip)
                return -ENODEV;

        tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_OIAP);
        ret = trusted_tpm_send(tb->data, tb->length);
        if (ret < 0)
                return ret;

        *handle = LOAD32(tb->data, TPM_DATA_OFFSET);
        memcpy(nonce, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)],
               TPM_NONCE_SIZE);
        return 0;
}

struct tpm_digests {
        unsigned char encauth[SHA1_DIGEST_SIZE];
        unsigned char pubauth[SHA1_DIGEST_SIZE];
        unsigned char xorwork[SHA1_DIGEST_SIZE * 2];
        unsigned char xorhash[SHA1_DIGEST_SIZE];
        unsigned char nonceodd[TPM_NONCE_SIZE];
};

/*
 * Have the TPM seal(encrypt) the trusted key, possibly based on
 * Platform Configuration Registers (PCRs). AUTH1 for sealing key.
 */
static int tpm_seal(struct tpm_buf *tb, uint16_t keytype,
                    uint32_t keyhandle, const unsigned char *keyauth,
                    const unsigned char *data, uint32_t datalen,
                    unsigned char *blob, uint32_t *bloblen,
                    const unsigned char *blobauth,
                    const unsigned char *pcrinfo, uint32_t pcrinfosize)
{
        struct osapsess sess;
        struct tpm_digests *td;
        unsigned char cont;
        uint32_t ordinal;
        uint32_t pcrsize;
        uint32_t datsize;
        int sealinfosize;
        int encdatasize;
        int storedsize;
        int ret;
        int i;

        /* alloc some work space for all the hashes */
        td = kmalloc_obj(*td);
        if (!td)
                return -ENOMEM;

        /* get session for sealing key */
        ret = osap(tb, &sess, keyauth, keytype, keyhandle);
        if (ret < 0)
                goto out;
        dump_sess(&sess);

        /* calculate encrypted authorization value */
        memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE);
        memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE);
        sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash);

        ret = tpm_get_random(chip, td->nonceodd, TPM_NONCE_SIZE);
        if (ret < 0)
                goto out;

        if (ret != TPM_NONCE_SIZE) {
                ret = -EIO;
                goto out;
        }

        ordinal = htonl(TPM_ORD_SEAL);
        datsize = htonl(datalen);
        pcrsize = htonl(pcrinfosize);
        cont = 0;

        /* encrypt data authorization key */
        for (i = 0; i < SHA1_DIGEST_SIZE; ++i)
                td->encauth[i] = td->xorhash[i] ^ blobauth[i];

        /* calculate authorization HMAC value */
        if (pcrinfosize == 0) {
                /* no pcr info specified */
                ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
                                   sess.enonce, td->nonceodd, cont,
                                   sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
                                   td->encauth, sizeof(uint32_t), &pcrsize,
                                   sizeof(uint32_t), &datsize, datalen, data, 0,
                                   0);
        } else {
                /* pcr info specified */
                ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
                                   sess.enonce, td->nonceodd, cont,
                                   sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
                                   td->encauth, sizeof(uint32_t), &pcrsize,
                                   pcrinfosize, pcrinfo, sizeof(uint32_t),
                                   &datsize, datalen, data, 0, 0);
        }
        if (ret < 0)
                goto out;

        /* build and send the TPM request packet */
        tpm_buf_reset(tb, TPM_TAG_RQU_AUTH1_COMMAND, TPM_ORD_SEAL);
        tpm_buf_append_u32(tb, keyhandle);
        tpm_buf_append(tb, td->encauth, SHA1_DIGEST_SIZE);
        tpm_buf_append_u32(tb, pcrinfosize);
        tpm_buf_append(tb, pcrinfo, pcrinfosize);
        tpm_buf_append_u32(tb, datalen);
        tpm_buf_append(tb, data, datalen);
        tpm_buf_append_u32(tb, sess.handle);
        tpm_buf_append(tb, td->nonceodd, TPM_NONCE_SIZE);
        tpm_buf_append_u8(tb, cont);
        tpm_buf_append(tb, td->pubauth, SHA1_DIGEST_SIZE);

        ret = trusted_tpm_send(tb->data, tb->length);
        if (ret < 0)
                goto out;

        /* calculate the size of the returned Blob */
        sealinfosize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t));
        encdatasize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t) +
                             sizeof(uint32_t) + sealinfosize);
        storedsize = sizeof(uint32_t) + sizeof(uint32_t) + sealinfosize +
            sizeof(uint32_t) + encdatasize;

        /* check the HMAC in the response */
        ret = TSS_checkhmac1(tb->data, ordinal, td->nonceodd, sess.secret,
                             SHA1_DIGEST_SIZE, storedsize, TPM_DATA_OFFSET, 0,
                             0);

        /* copy the returned blob to caller */
        if (!ret) {
                memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize);
                *bloblen = storedsize;
        }
out:
        kfree_sensitive(td);
        return ret;
}

/*
 * use the AUTH2_COMMAND form of unseal, to authorize both key and blob
 */
static int tpm_unseal(struct tpm_buf *tb,
                      uint32_t keyhandle, const unsigned char *keyauth,
                      const unsigned char *blob, int bloblen,
                      const unsigned char *blobauth,
                      unsigned char *data, unsigned int *datalen)
{
        unsigned char nonceodd[TPM_NONCE_SIZE];
        unsigned char enonce1[TPM_NONCE_SIZE];
        unsigned char enonce2[TPM_NONCE_SIZE];
        unsigned char authdata1[SHA1_DIGEST_SIZE];
        unsigned char authdata2[SHA1_DIGEST_SIZE];
        uint32_t authhandle1 = 0;
        uint32_t authhandle2 = 0;
        unsigned char cont = 0;
        uint32_t ordinal;
        int ret;

        /* sessions for unsealing key and data */
        ret = oiap(tb, &authhandle1, enonce1);
        if (ret < 0) {
                pr_info("oiap failed (%d)\n", ret);
                return ret;
        }
        ret = oiap(tb, &authhandle2, enonce2);
        if (ret < 0) {
                pr_info("oiap failed (%d)\n", ret);
                return ret;
        }

        ordinal = htonl(TPM_ORD_UNSEAL);
        ret = tpm_get_random(chip, nonceodd, TPM_NONCE_SIZE);
        if (ret < 0)
                return ret;

        if (ret != TPM_NONCE_SIZE) {
                pr_info("tpm_get_random failed (%d)\n", ret);
                return -EIO;
        }
        ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE,
                           enonce1, nonceodd, cont, sizeof(uint32_t),
                           &ordinal, bloblen, blob, 0, 0);
        if (ret < 0)
                return ret;
        ret = TSS_authhmac(authdata2, blobauth, TPM_NONCE_SIZE,
                           enonce2, nonceodd, cont, sizeof(uint32_t),
                           &ordinal, bloblen, blob, 0, 0);
        if (ret < 0)
                return ret;

        /* build and send TPM request packet */
        tpm_buf_reset(tb, TPM_TAG_RQU_AUTH2_COMMAND, TPM_ORD_UNSEAL);
        tpm_buf_append_u32(tb, keyhandle);
        tpm_buf_append(tb, blob, bloblen);
        tpm_buf_append_u32(tb, authhandle1);
        tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
        tpm_buf_append_u8(tb, cont);
        tpm_buf_append(tb, authdata1, SHA1_DIGEST_SIZE);
        tpm_buf_append_u32(tb, authhandle2);
        tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
        tpm_buf_append_u8(tb, cont);
        tpm_buf_append(tb, authdata2, SHA1_DIGEST_SIZE);

        ret = trusted_tpm_send(tb->data, tb->length);
        if (ret < 0) {
                pr_info("authhmac failed (%d)\n", ret);
                return ret;
        }

        *datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
        ret = TSS_checkhmac2(tb->data, ordinal, nonceodd,
                             keyauth, SHA1_DIGEST_SIZE,
                             blobauth, SHA1_DIGEST_SIZE,
                             sizeof(uint32_t), TPM_DATA_OFFSET,
                             *datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0,
                             0);
        if (ret < 0) {
                pr_info("TSS_checkhmac2 failed (%d)\n", ret);
                return ret;
        }
        memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen);
        return 0;
}

/*
 * Have the TPM seal(encrypt) the symmetric key
 */
static int key_seal(struct trusted_key_payload *p,
                    struct trusted_key_options *o)
{
        struct tpm_buf tb;
        int ret;

        ret = tpm_buf_init(&tb, 0, 0);
        if (ret)
                return ret;

        /* include migratable flag at end of sealed key */
        p->key[p->key_len] = p->migratable;

        ret = tpm_seal(&tb, o->keytype, o->keyhandle, o->keyauth,
                       p->key, p->key_len + 1, p->blob, &p->blob_len,
                       o->blobauth, o->pcrinfo, o->pcrinfo_len);
        if (ret < 0)
                pr_info("srkseal failed (%d)\n", ret);

        tpm_buf_destroy(&tb);
        return ret;
}

/*
 * Have the TPM unseal(decrypt) the symmetric key
 */
static int key_unseal(struct trusted_key_payload *p,
                      struct trusted_key_options *o)
{
        struct tpm_buf tb;
        int ret;

        ret = tpm_buf_init(&tb, 0, 0);
        if (ret)
                return ret;

        ret = tpm_unseal(&tb, o->keyhandle, o->keyauth, p->blob, p->blob_len,
                         o->blobauth, p->key, &p->key_len);
        if (ret < 0)
                pr_info("srkunseal failed (%d)\n", ret);
        else
                /* pull migratable flag out of sealed key */
                p->migratable = p->key[--p->key_len];

        tpm_buf_destroy(&tb);
        return ret;
}

enum {
        Opt_err,
        Opt_keyhandle, Opt_keyauth, Opt_blobauth,
        Opt_pcrinfo, Opt_pcrlock, Opt_migratable,
        Opt_hash,
        Opt_policydigest,
        Opt_policyhandle,
};

static const match_table_t key_tokens = {
        {Opt_keyhandle, "keyhandle=%s"},
        {Opt_keyauth, "keyauth=%s"},
        {Opt_blobauth, "blobauth=%s"},
        {Opt_pcrinfo, "pcrinfo=%s"},
        {Opt_pcrlock, "pcrlock=%s"},
        {Opt_migratable, "migratable=%s"},
        {Opt_hash, "hash=%s"},
        {Opt_policydigest, "policydigest=%s"},
        {Opt_policyhandle, "policyhandle=%s"},
        {Opt_err, NULL}
};

/* can have zero or more token= options */
static int getoptions(char *c, struct trusted_key_payload *pay,
                      struct trusted_key_options *opt)
{
        substring_t args[MAX_OPT_ARGS];
        char *p = c;
        int token;
        int res;
        unsigned long handle;
        unsigned long lock;
        unsigned long token_mask = 0;
        unsigned int digest_len;
        int i;
        int tpm2;

        tpm2 = tpm_is_tpm2(chip);
        if (tpm2 < 0)
                return tpm2;

        opt->hash = tpm2 ? HASH_ALGO_SHA256 : HASH_ALGO_SHA1;

        if (!c)
                return 0;

        while ((p = strsep(&c, " \t"))) {
                if (*p == '\0' || *p == ' ' || *p == '\t')
                        continue;
                token = match_token(p, key_tokens, args);
                if (test_and_set_bit(token, &token_mask))
                        return -EINVAL;

                switch (token) {
                case Opt_pcrinfo:
                        opt->pcrinfo_len = strlen(args[0].from) / 2;
                        if (opt->pcrinfo_len > MAX_PCRINFO_SIZE)
                                return -EINVAL;
                        res = hex2bin(opt->pcrinfo, args[0].from,
                                      opt->pcrinfo_len);
                        if (res < 0)
                                return -EINVAL;
                        break;
                case Opt_keyhandle:
                        res = kstrtoul(args[0].from, 16, &handle);
                        if (res < 0)
                                return -EINVAL;
                        opt->keytype = SEAL_keytype;
                        opt->keyhandle = handle;
                        break;
                case Opt_keyauth:
                        if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
                                return -EINVAL;
                        res = hex2bin(opt->keyauth, args[0].from,
                                      SHA1_DIGEST_SIZE);
                        if (res < 0)
                                return -EINVAL;
                        break;
                case Opt_blobauth:
                        /*
                         * TPM 1.2 authorizations are sha1 hashes passed in as
                         * hex strings.  TPM 2.0 authorizations are simple
                         * passwords (although it can take a hash as well)
                         */
                        opt->blobauth_len = strlen(args[0].from);

                        if (opt->blobauth_len == 2 * TPM_DIGEST_SIZE) {
                                res = hex2bin(opt->blobauth, args[0].from,
                                              TPM_DIGEST_SIZE);
                                if (res < 0)
                                        return -EINVAL;

                                opt->blobauth_len = TPM_DIGEST_SIZE;
                                break;
                        }

                        if (tpm2 && opt->blobauth_len <= sizeof(opt->blobauth)) {
                                memcpy(opt->blobauth, args[0].from,
                                       opt->blobauth_len);
                                break;
                        }

                        return -EINVAL;

                        break;

                case Opt_migratable:
                        if (*args[0].from == '0')
                                pay->migratable = 0;
                        else if (*args[0].from != '1')
                                return -EINVAL;
                        break;
                case Opt_pcrlock:
                        res = kstrtoul(args[0].from, 10, &lock);
                        if (res < 0)
                                return -EINVAL;
                        opt->pcrlock = lock;
                        break;
                case Opt_hash:
                        if (test_bit(Opt_policydigest, &token_mask))
                                return -EINVAL;
                        for (i = 0; i < HASH_ALGO__LAST; i++) {
                                if (!strcmp(args[0].from, hash_algo_name[i])) {
                                        opt->hash = i;
                                        break;
                                }
                        }
                        if (i == HASH_ALGO__LAST)
                                return -EINVAL;
                        if  (!tpm2 && i != HASH_ALGO_SHA1) {
                                pr_info("TPM 1.x only supports SHA-1.\n");
                                return -EINVAL;
                        }
                        break;
                case Opt_policydigest:
                        digest_len = hash_digest_size[opt->hash];
                        if (!tpm2 || strlen(args[0].from) != (2 * digest_len))
                                return -EINVAL;
                        res = hex2bin(opt->policydigest, args[0].from,
                                      digest_len);
                        if (res < 0)
                                return -EINVAL;
                        opt->policydigest_len = digest_len;
                        break;
                case Opt_policyhandle:
                        if (!tpm2)
                                return -EINVAL;
                        res = kstrtoul(args[0].from, 16, &handle);
                        if (res < 0)
                                return -EINVAL;
                        opt->policyhandle = handle;
                        break;
                default:
                        return -EINVAL;
                }
        }
        return 0;
}

static struct trusted_key_options *trusted_options_alloc(void)
{
        struct trusted_key_options *options;
        int tpm2;

        tpm2 = tpm_is_tpm2(chip);
        if (tpm2 < 0)
                return NULL;

        options = kzalloc_obj(*options);
        if (options) {
                /* set any non-zero defaults */
                options->keytype = SRK_keytype;

                if (!tpm2)
                        options->keyhandle = SRKHANDLE;
        }
        return options;
}

static int trusted_tpm_seal(struct trusted_key_payload *p, char *datablob)
{
        struct trusted_key_options *options = NULL;
        int ret = 0;
        int tpm2;

        tpm2 = tpm_is_tpm2(chip);
        if (tpm2 < 0)
                return tpm2;

        options = trusted_options_alloc();
        if (!options)
                return -ENOMEM;

        ret = getoptions(datablob, p, options);
        if (ret < 0)
                goto out;
        dump_options(options);

        if (!options->keyhandle && !tpm2) {
                ret = -EINVAL;
                goto out;
        }

        if (tpm2)
                ret = tpm2_seal_trusted(chip, p, options);
        else
                ret = key_seal(p, options);
        if (ret < 0) {
                pr_info("key_seal failed (%d)\n", ret);
                goto out;
        }

        if (options->pcrlock) {
                ret = pcrlock(options->pcrlock);
                if (ret < 0) {
                        pr_info("pcrlock failed (%d)\n", ret);
                        goto out;
                }
        }
out:
        kfree_sensitive(options);
        return ret;
}

static int trusted_tpm_unseal(struct trusted_key_payload *p, char *datablob)
{
        struct trusted_key_options *options = NULL;
        int ret = 0;
        int tpm2;

        tpm2 = tpm_is_tpm2(chip);
        if (tpm2 < 0)
                return tpm2;

        options = trusted_options_alloc();
        if (!options)
                return -ENOMEM;

        ret = getoptions(datablob, p, options);
        if (ret < 0)
                goto out;
        dump_options(options);

        if (!options->keyhandle && !tpm2) {
                ret = -EINVAL;
                goto out;
        }

        if (tpm2)
                ret = tpm2_unseal_trusted(chip, p, options);
        else
                ret = key_unseal(p, options);
        if (ret < 0)
                pr_info("key_unseal failed (%d)\n", ret);

        if (options->pcrlock) {
                ret = pcrlock(options->pcrlock);
                if (ret < 0) {
                        pr_info("pcrlock failed (%d)\n", ret);
                        goto out;
                }
        }
out:
        kfree_sensitive(options);
        return ret;
}

static int trusted_tpm_get_random(unsigned char *key, size_t key_len)
{
        return tpm_get_random(chip, key, key_len);
}

static int __init init_digests(void)
{
        int i;

        digests = kzalloc_objs(*digests, chip->nr_allocated_banks);
        if (!digests)
                return -ENOMEM;

        for (i = 0; i < chip->nr_allocated_banks; i++)
                digests[i].alg_id = chip->allocated_banks[i].alg_id;

        return 0;
}

static int __init trusted_tpm_init(void)
{
        int ret;

        chip = tpm_default_chip();
        if (!chip)
                return -ENODEV;

        ret = init_digests();
        if (ret < 0)
                goto err_put;
        ret = register_key_type(&key_type_trusted);
        if (ret < 0)
                goto err_free;
        return 0;
err_free:
        kfree(digests);
err_put:
        put_device(&chip->dev);
        return ret;
}

static void trusted_tpm_exit(void)
{
        if (chip) {
                put_device(&chip->dev);
                kfree(digests);
                unregister_key_type(&key_type_trusted);
        }
}

struct trusted_key_ops trusted_key_tpm_ops = {
        .migratable = 1, /* migratable by default */
        .init = trusted_tpm_init,
        .seal = trusted_tpm_seal,
        .unseal = trusted_tpm_unseal,
        .get_random = trusted_tpm_get_random,
        .exit = trusted_tpm_exit,
};