diff options
Diffstat (limited to 'drivers/char/tpm/tpm2-cmd.c')
| -rw-r--r-- | drivers/char/tpm/tpm2-cmd.c | 250 |
1 files changed, 249 insertions, 1 deletions
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index 011909a9be96..bd7039fafa8a 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 2014 Intel Corporation + * Copyright (C) 2014, 2015 Intel Corporation * * Authors: * Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> @@ -16,6 +16,11 @@ */ #include "tpm.h" +#include <keys/trusted-type.h> + +enum tpm2_object_attributes { + TPM2_ATTR_USER_WITH_AUTH = BIT(6), +}; struct tpm2_startup_in { __be16 startup_type; @@ -381,6 +386,249 @@ static const struct tpm_input_header tpm2_get_tpm_pt_header = { }; /** + * Append TPMS_AUTH_COMMAND to the buffer. The buffer must be allocated with + * tpm_buf_alloc(). + * + * @param buf: an allocated tpm_buf instance + * @param nonce: the session nonce, may be NULL if not used + * @param nonce_len: the session nonce length, may be 0 if not used + * @param attributes: the session attributes + * @param hmac: the session HMAC or password, may be NULL if not used + * @param hmac_len: the session HMAC or password length, maybe 0 if not used + */ +static void tpm2_buf_append_auth(struct tpm_buf *buf, u32 session_handle, + const u8 *nonce, u16 nonce_len, + u8 attributes, + const u8 *hmac, u16 hmac_len) +{ + tpm_buf_append_u32(buf, 9 + nonce_len + hmac_len); + tpm_buf_append_u32(buf, session_handle); + tpm_buf_append_u16(buf, nonce_len); + + if (nonce && nonce_len) + tpm_buf_append(buf, nonce, nonce_len); + + tpm_buf_append_u8(buf, attributes); + tpm_buf_append_u16(buf, hmac_len); + + if (hmac && hmac_len) + tpm_buf_append(buf, hmac, hmac_len); +} + +/** + * tpm2_seal_trusted() - seal a trusted key + * @chip_num: A specific chip number for the request or TPM_ANY_NUM + * @options: authentication values and other options + * @payload: the key data in clear and encrypted form + * + * Returns < 0 on error and 0 on success. + */ +int tpm2_seal_trusted(struct tpm_chip *chip, + struct trusted_key_payload *payload, + struct trusted_key_options *options) +{ + unsigned int blob_len; + struct tpm_buf buf; + int rc; + + rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_CREATE); + if (rc) + return rc; + + tpm_buf_append_u32(&buf, options->keyhandle); + tpm2_buf_append_auth(&buf, TPM2_RS_PW, + NULL /* nonce */, 0, + 0 /* session_attributes */, + options->keyauth /* hmac */, + TPM_DIGEST_SIZE); + + /* sensitive */ + tpm_buf_append_u16(&buf, 4 + TPM_DIGEST_SIZE + payload->key_len); + + tpm_buf_append_u16(&buf, TPM_DIGEST_SIZE); + tpm_buf_append(&buf, options->blobauth, TPM_DIGEST_SIZE); + tpm_buf_append_u16(&buf, payload->key_len); + tpm_buf_append(&buf, payload->key, payload->key_len); + + /* public */ + tpm_buf_append_u16(&buf, 14); + + tpm_buf_append_u16(&buf, TPM2_ALG_KEYEDHASH); + tpm_buf_append_u16(&buf, TPM2_ALG_SHA256); + tpm_buf_append_u32(&buf, TPM2_ATTR_USER_WITH_AUTH); + tpm_buf_append_u16(&buf, 0); /* policy digest size */ + tpm_buf_append_u16(&buf, TPM2_ALG_NULL); + tpm_buf_append_u16(&buf, 0); + + /* outside info */ + tpm_buf_append_u16(&buf, 0); + + /* creation PCR */ + tpm_buf_append_u32(&buf, 0); + + if (buf.flags & TPM_BUF_OVERFLOW) { + rc = -E2BIG; + goto out; + } + + rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "sealing data"); + if (rc) + goto out; + + blob_len = be32_to_cpup((__be32 *) &buf.data[TPM_HEADER_SIZE]); + if (blob_len > MAX_BLOB_SIZE) { + rc = -E2BIG; + goto out; + } + + memcpy(payload->blob, &buf.data[TPM_HEADER_SIZE + 4], blob_len); + payload->blob_len = blob_len; + +out: + tpm_buf_destroy(&buf); + + if (rc > 0) + rc = -EPERM; + + return rc; +} + +static int tpm2_load(struct tpm_chip *chip, + struct trusted_key_payload *payload, + struct trusted_key_options *options, + u32 *blob_handle) +{ + struct tpm_buf buf; + unsigned int private_len; + unsigned int public_len; + unsigned int blob_len; + int rc; + + private_len = be16_to_cpup((__be16 *) &payload->blob[0]); + if (private_len > (payload->blob_len - 2)) + return -E2BIG; + + public_len = be16_to_cpup((__be16 *) &payload->blob[2 + private_len]); + blob_len = private_len + public_len + 4; + if (blob_len > payload->blob_len) + return -E2BIG; + + rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_LOAD); + if (rc) + return rc; + + tpm_buf_append_u32(&buf, options->keyhandle); + tpm2_buf_append_auth(&buf, TPM2_RS_PW, + NULL /* nonce */, 0, + 0 /* session_attributes */, + options->keyauth /* hmac */, + TPM_DIGEST_SIZE); + + tpm_buf_append(&buf, payload->blob, blob_len); + + if (buf.flags & TPM_BUF_OVERFLOW) { + rc = -E2BIG; + goto out; + } + + rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "loading blob"); + if (!rc) + *blob_handle = be32_to_cpup( + (__be32 *) &buf.data[TPM_HEADER_SIZE]); + +out: + tpm_buf_destroy(&buf); + + if (rc > 0) + rc = -EPERM; + + return rc; +} + +static void tpm2_flush_context(struct tpm_chip *chip, u32 handle) +{ + struct tpm_buf buf; + int rc; + + rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_FLUSH_CONTEXT); + if (rc) { + dev_warn(chip->pdev, "0x%08x was not flushed, out of memory\n", + handle); + return; + } + + tpm_buf_append_u32(&buf, handle); + + rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "flushing context"); + if (rc) + dev_warn(chip->pdev, "0x%08x was not flushed, rc=%d\n", handle, + rc); + + tpm_buf_destroy(&buf); +} + +static int tpm2_unseal(struct tpm_chip *chip, + struct trusted_key_payload *payload, + struct trusted_key_options *options, + u32 blob_handle) +{ + struct tpm_buf buf; + int rc; + + rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_UNSEAL); + if (rc) + return rc; + + tpm_buf_append_u32(&buf, blob_handle); + tpm2_buf_append_auth(&buf, TPM2_RS_PW, + NULL /* nonce */, 0, + 0 /* session_attributes */, + options->blobauth /* hmac */, + TPM_DIGEST_SIZE); + + rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "unsealing"); + if (rc > 0) + rc = -EPERM; + + if (!rc) { + payload->key_len = be16_to_cpup( + (__be16 *) &buf.data[TPM_HEADER_SIZE + 4]); + + memcpy(payload->key, &buf.data[TPM_HEADER_SIZE + 6], + payload->key_len); + } + + tpm_buf_destroy(&buf); + return rc; +} + +/** + * tpm_unseal_trusted() - unseal a trusted key + * @chip_num: A specific chip number for the request or TPM_ANY_NUM + * @options: authentication values and other options + * @payload: the key data in clear and encrypted form + * + * Returns < 0 on error and 0 on success. + */ +int tpm2_unseal_trusted(struct tpm_chip *chip, + struct trusted_key_payload *payload, + struct trusted_key_options *options) +{ + u32 blob_handle; + int rc; + + rc = tpm2_load(chip, payload, options, &blob_handle); + if (rc) + return rc; + + rc = tpm2_unseal(chip, payload, options, blob_handle); + + tpm2_flush_context(chip, blob_handle); + + return rc; +} + +/** * tpm2_get_tpm_pt() - get value of a TPM_CAP_TPM_PROPERTIES type property * @chip: TPM chip to use. * @property_id: property ID. |