[U-Boot] [PATCH 1/6] tpm: add AUTH1 cmds for LoadKey2 and GetPubKey
Che-liang Chiou
clchiou at chromium.org
Mon Apr 22 19:51:12 CEST 2013
Acked-by: Che-Liang Chiou <clchiou at chromium.org>
On Mon, Apr 22, 2013 at 4:06 AM, Dirk Eibach <eibach at gdsys.de> wrote:
> From: Reinhard Pfau <pfau at gdsys.de>
>
> Extend the tpm library with support for single authorized (AUTH1) commands
> as specified in the TCG Main Specification 1.2. (The internally used helper
> functions are implemented in a way that they could also be used for double
> authorized commands if someone needs it.)
>
> Provide enums with the return codes from the TCG Main specification.
>
> For now only a single OIAP session is supported.
>
> OIAP authorized version of the commands TPM_LoadKey2 and TPM_GetPubKey are
> provided. Both features are available using the 'tpm' command, too.
>
> Authorized commands are enabled with CONFIG_TPM_AUTH_SESSIONS. (Note that
> this also requires CONFIG_SHA1 to be enabled.)
>
> Signed-off-by: Reinhard Pfau <pfau at gdsys.de>
>
> Signed-off-by: Dirk Eibach <eibach at gdsys.de>
> ---
> README | 14 +++
> common/cmd_tpm.c | 93 +++++++++++++++
> include/tpm.h | 174 +++++++++++++++++++++++++++
> lib/tpm.c | 348 +++++++++++++++++++++++++++++++++++++++++++++++++++++-
> 4 files changed, 628 insertions(+), 1 deletion(-)
>
> diff --git a/README b/README
> index 0bc0af5..58b2ee5 100644
> --- a/README
> +++ b/README
> @@ -1210,6 +1210,20 @@ The following options need to be configured:
> to. Contemporary x86 systems usually map it at
> 0xfed40000.
>
> + CONFIG_CMD_TPM
> + Add tpm monitor functions.
> + Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
> + provides monitor access to authorized functions.
> +
> + CONFIG_TPM
> + Define this to enable the TPM support library which provides
> + functional interfaces to some TPM commands.
> + Requires support for a TPM device.
> +
> + CONFIG_TPM_AUTH_SESSIONS
> + Define this to enable authorized functions in the TPM library.
> + Requires CONFIG_TPM and CONFIG_SHA1.
> +
> - USB Support:
> At the moment only the UHCI host controller is
> supported (PIP405, MIP405, MPC5200); define
> diff --git a/common/cmd_tpm.c b/common/cmd_tpm.c
> index 46fae18..c8767a4 100644
> --- a/common/cmd_tpm.c
> +++ b/common/cmd_tpm.c
> @@ -546,6 +546,72 @@ static int do_tpm_nv_write(cmd_tbl_t *cmdtp, int flag,
> return convert_return_code(err);
> }
>
> +#ifdef CONFIG_TPM_AUTH_SESSIONS
> +
> +static int do_tpm_oiap(cmd_tbl_t *cmdtp, int flag,
> + int argc, char * const argv[])
> +{
> + uint32_t auth_handle, err;
> +
> + err = tpm_oiap(&auth_handle);
> +
> + return convert_return_code(err);
> +}
> +
> +static int do_tpm_load_key2_oiap(cmd_tbl_t *cmdtp, int flag,
> + int argc, char * const argv[])
> +{
> + uint32_t parent_handle, key_len, key_handle, err;
> + uint8_t usage_auth[20];
> + void *key;
> +
> + if (argc < 5)
> + return CMD_RET_USAGE;
> +
> + parent_handle = simple_strtoul(argv[1], NULL, 0);
> + key = (void *)simple_strtoul(argv[2], NULL, 0);
> + key_len = simple_strtoul(argv[3], NULL, 0);
> + if (strlen(argv[4]) != 40)
> + return CMD_RET_FAILURE;
> + parse_byte_string(argv[4], usage_auth, NULL);
> +
> + err = tpm_load_key2_oiap(parent_handle, key, key_len, usage_auth,
> + &key_handle);
> + if (!err)
> + printf("Key handle is 0x%x\n", key_handle);
> +
> + return convert_return_code(err);
> +}
> +
> +static int do_tpm_get_pub_key_oiap(cmd_tbl_t *cmdtp, int flag,
> + int argc, char * const argv[])
> +{
> + uint32_t key_handle, err;
> + uint8_t usage_auth[20];
> + uint8_t pub_key_buffer[288];
> + size_t pub_key_len = sizeof(pub_key_buffer);
> +
> + if (argc < 3)
> + return CMD_RET_USAGE;
> +
> + key_handle = simple_strtoul(argv[1], NULL, 0);
> + if (strlen(argv[2]) != 40)
> + return CMD_RET_FAILURE;
> + parse_byte_string(argv[2], usage_auth, NULL);
> +
> + err = tpm_get_pub_key_oiap(key_handle, usage_auth,
> + pub_key_buffer, &pub_key_len);
> + if (!err) {
> + printf("dump of received pub key structure:\n");
> + print_byte_string(pub_key_buffer, pub_key_len);
> + }
> + return convert_return_code(err);
> +}
> +
> +TPM_COMMAND_NO_ARG(tpm_end_oiap)
> +
> +#endif /* CONFIG_TPM_AUTH_SESSIONS */
> +
> #define MAKE_TPM_CMD_ENTRY(cmd) \
> U_BOOT_CMD_MKENT(cmd, 0, 1, do_tpm_ ## cmd, "", "")
>
> @@ -590,6 +656,16 @@ static cmd_tbl_t tpm_commands[] = {
> do_tpm_nv_read, "", ""),
> U_BOOT_CMD_MKENT(nv_write, 0, 1,
> do_tpm_nv_write, "", ""),
> +#ifdef CONFIG_TPM_AUTH_SESSIONS
> + U_BOOT_CMD_MKENT(oiap, 0, 1,
> + do_tpm_oiap, "", ""),
> + U_BOOT_CMD_MKENT(end_oiap, 0, 1,
> + do_tpm_end_oiap, "", ""),
> + U_BOOT_CMD_MKENT(load_key2_oiap, 0, 1,
> + do_tpm_load_key2_oiap, "", ""),
> + U_BOOT_CMD_MKENT(get_pub_key_oiap, 0, 1,
> + do_tpm_get_pub_key_oiap, "", ""),
> +#endif /* CONFIG_TPM_AUTH_SESSIONS */
> };
>
> static int do_tpm(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
> @@ -638,6 +714,16 @@ U_BOOT_CMD(tpm, CONFIG_SYS_MAXARGS, 1, do_tpm,
> " get_capability cap_area sub_cap addr count\n"
> " - Read <count> bytes of TPM capability indexed by <cap_area> and\n"
> " <sub_cap> to memory address <addr>.\n"
> +#ifdef CONFIG_TPM_AUTH_SESSIONS
> +"Storage functions\n"
> +" loadkey2_oiap parent_handle key_addr key_len usage_auth\n"
> +" - loads a key data from memory address <key_addr>, <key_len> bytes\n"
> +" into TPM using the parent key <parent_handle> with authorization\n"
> +" <usage_auth> (20 bytes hex string).\n"
> +" get_pub_key_oiap key_handle usage_auth\n"
> +" - get the public key portion of a loaded key <key_handle> using\n"
> +" authorization <usage auth> (20 bytes hex string)\n"
> +#endif /* CONFIG_TPM_AUTH_SESSIONS */
> "Endorsement Key Handling Commands:\n"
> " read_pubek addr count\n"
> " - Read <count> bytes of the public endorsement key to memory\n"
> @@ -648,6 +734,13 @@ U_BOOT_CMD(tpm, CONFIG_SYS_MAXARGS, 1, do_tpm,
> " <digest_hex_string>\n"
> " pcr_read index addr count\n"
> " - Read <count> bytes from PCR <index> to memory address <addr>.\n"
> +#ifdef CONFIG_TPM_AUTH_SESSIONS
> +"Authorization Sessions\n"
> +" oiap\n"
> +" - setup an OIAP session\n"
> +" end_oiap\n"
> +" - terminates an active OIAP session\n"
> +#endif /* CONFIG_TPM_AUTH_SESSIONS */
> "Non-volatile Storage Commands:\n"
> " nv_define_space index permission size\n"
> " - Establish a space at index <index> with <permission> of <size> bytes.\n"
> diff --git a/include/tpm.h b/include/tpm.h
> index 7219b73..5e9f832 100644
> --- a/include/tpm.h
> +++ b/include/tpm.h
> @@ -1,5 +1,6 @@
> /*
> * Copyright (c) 2013 The Chromium OS Authors.
> + * Coypright (c) 2013 Guntermann & Drunck GmbH
> *
> * See file CREDITS for list of people who contributed to this
> * project.
> @@ -54,6 +55,120 @@ enum tpm_nv_index {
> };
>
> /**
> + * TPM return codes as defined in the TCG Main specification
> + * (TPM Main Part 2 Structures; Specification version 1.2)
> + */
> +enum tpm_return_code {
> + TPM_BASE = 0x00000000,
> + TPM_NON_FATAL = 0x00000800,
> + TPM_SUCCESS = TPM_BASE,
> + /* TPM-defined fatal error codes */
> + TPM_AUTHFAIL = TPM_BASE + 1,
> + TPM_BADINDEX = TPM_BASE + 2,
> + TPM_BAD_PARAMETER = TPM_BASE + 3,
> + TPM_AUDITFAILURE = TPM_BASE + 4,
> + TPM_CLEAR_DISABLED = TPM_BASE + 5,
> + TPM_DEACTIVATED = TPM_BASE + 6,
> + TPM_DISABLED = TPM_BASE + 7,
> + TPM_DISABLED_CMD = TPM_BASE + 8,
> + TPM_FAIL = TPM_BASE + 9,
> + TPM_BAD_ORDINAL = TPM_BASE + 10,
> + TPM_INSTALL_DISABLED = TPM_BASE + 11,
> + TPM_INVALID_KEYHANDLE = TPM_BASE + 12,
> + TPM_KEYNOTFOUND = TPM_BASE + 13,
> + TPM_INAPPROPRIATE_ENC = TPM_BASE + 14,
> + TPM_MIGRATE_FAIL = TPM_BASE + 15,
> + TPM_INVALID_PCR_INFO = TPM_BASE + 16,
> + TPM_NOSPACE = TPM_BASE + 17,
> + TPM_NOSRK = TPM_BASE + 18,
> + TPM_NOTSEALED_BLOB = TPM_BASE + 19,
> + TPM_OWNER_SET = TPM_BASE + 20,
> + TPM_RESOURCES = TPM_BASE + 21,
> + TPM_SHORTRANDOM = TPM_BASE + 22,
> + TPM_SIZE = TPM_BASE + 23,
> + TPM_WRONGPCRVAL = TPM_BASE + 24,
> + TPM_BAD_PARAM_SIZE = TPM_BASE + 25,
> + TPM_SHA_THREAD = TPM_BASE + 26,
> + TPM_SHA_ERROR = TPM_BASE + 27,
> + TPM_FAILEDSELFTEST = TPM_BASE + 28,
> + TPM_AUTH2FAIL = TPM_BASE + 29,
> + TPM_BADTAG = TPM_BASE + 30,
> + TPM_IOERROR = TPM_BASE + 31,
> + TPM_ENCRYPT_ERROR = TPM_BASE + 32,
> + TPM_DECRYPT_ERROR = TPM_BASE + 33,
> + TPM_INVALID_AUTHHANDLE = TPM_BASE + 34,
> + TPM_NO_ENDORSEMENT = TPM_BASE + 35,
> + TPM_INVALID_KEYUSAGE = TPM_BASE + 36,
> + TPM_WRONG_ENTITYTYPE = TPM_BASE + 37,
> + TPM_INVALID_POSTINIT = TPM_BASE + 38,
> + TPM_INAPPROPRIATE_SIG = TPM_BASE + 39,
> + TPM_BAD_KEY_PROPERTY = TPM_BASE + 40,
> + TPM_BAD_MIGRATION = TPM_BASE + 41,
> + TPM_BAD_SCHEME = TPM_BASE + 42,
> + TPM_BAD_DATASIZE = TPM_BASE + 43,
> + TPM_BAD_MODE = TPM_BASE + 44,
> + TPM_BAD_PRESENCE = TPM_BASE + 45,
> + TPM_BAD_VERSION = TPM_BASE + 46,
> + TPM_NO_WRAP_TRANSPORT = TPM_BASE + 47,
> + TPM_AUDITFAIL_UNSUCCESSFUL = TPM_BASE + 48,
> + TPM_AUDITFAIL_SUCCESSFUL = TPM_BASE + 49,
> + TPM_NOTRESETABLE = TPM_BASE + 50,
> + TPM_NOTLOCAL = TPM_BASE + 51,
> + TPM_BAD_TYPE = TPM_BASE + 52,
> + TPM_INVALID_RESOURCE = TPM_BASE + 53,
> + TPM_NOTFIPS = TPM_BASE + 54,
> + TPM_INVALID_FAMILY = TPM_BASE + 55,
> + TPM_NO_NV_PERMISSION = TPM_BASE + 56,
> + TPM_REQUIRES_SIGN = TPM_BASE + 57,
> + TPM_KEY_NOTSUPPORTED = TPM_BASE + 58,
> + TPM_AUTH_CONFLICT = TPM_BASE + 59,
> + TPM_AREA_LOCKED = TPM_BASE + 60,
> + TPM_BAD_LOCALITY = TPM_BASE + 61,
> + TPM_READ_ONLY = TPM_BASE + 62,
> + TPM_PER_NOWRITE = TPM_BASE + 63,
> + TPM_FAMILY_COUNT = TPM_BASE + 64,
> + TPM_WRITE_LOCKED = TPM_BASE + 65,
> + TPM_BAD_ATTRIBUTES = TPM_BASE + 66,
> + TPM_INVALID_STRUCTURE = TPM_BASE + 67,
> + TPM_KEY_OWNER_CONTROL = TPM_BASE + 68,
> + TPM_BAD_COUNTER = TPM_BASE + 69,
> + TPM_NOT_FULLWRITE = TPM_BASE + 70,
> + TPM_CONTEXT_GAP = TPM_BASE + 71,
> + TPM_MAXNVWRITES = TPM_BASE + 72,
> + TPM_NOOPERATOR = TPM_BASE + 73,
> + TPM_RESOURCEMISSING = TPM_BASE + 74,
> + TPM_DELEGATE_LOCK = TPM_BASE + 75,
> + TPM_DELEGATE_FAMILY = TPM_BASE + 76,
> + TPM_DELEGATE_ADMIN = TPM_BASE + 77,
> + TPM_TRANSPORT_NOTEXCLUSIVE = TPM_BASE + 78,
> + TPM_OWNER_CONTROL = TPM_BASE + 79,
> + TPM_DAA_RESOURCES = TPM_BASE + 80,
> + TPM_DAA_INPUT_DATA0 = TPM_BASE + 81,
> + TPM_DAA_INPUT_DATA1 = TPM_BASE + 82,
> + TPM_DAA_ISSUER_SETTINGS = TPM_BASE + 83,
> + TPM_DAA_TPM_SETTINGS = TPM_BASE + 84,
> + TPM_DAA_STAGE = TPM_BASE + 85,
> + TPM_DAA_ISSUER_VALIDITY = TPM_BASE + 86,
> + TPM_DAA_WRONG_W = TPM_BASE + 87,
> + TPM_BAD_HANDLE = TPM_BASE + 88,
> + TPM_BAD_DELEGATE = TPM_BASE + 89,
> + TPM_BADCONTEXT = TPM_BASE + 90,
> + TPM_TOOMANYCONTEXTS = TPM_BASE + 91,
> + TPM_MA_TICKET_SIGNATURE = TPM_BASE + 92,
> + TPM_MA_DESTINATION = TPM_BASE + 93,
> + TPM_MA_SOURCE = TPM_BASE + 94,
> + TPM_MA_AUTHORITY = TPM_BASE + 95,
> + TPM_PERMANENTEK = TPM_BASE + 97,
> + TPM_BAD_SIGNATURE = TPM_BASE + 98,
> + TPM_NOCONTEXTSPACE = TPM_BASE + 99,
> + /* TPM-defined non-fatal errors */
> + TPM_RETRY = TPM_BASE + TPM_NON_FATAL,
> + TPM_NEEDS_SELFTEST = TPM_BASE + TPM_NON_FATAL + 1,
> + TPM_DOING_SELFTEST = TPM_BASE + TPM_NON_FATAL + 2,
> + TPM_DEFEND_LOCK_RUNNING = TPM_BASE + TPM_NON_FATAL + 3,
> +};
> +
> +/**
> * Initialize TPM device. It must be called before any TPM commands.
> *
> * @return 0 on success, non-0 on error.
> @@ -201,4 +316,63 @@ uint32_t tpm_physical_set_deactivated(uint8_t state);
> uint32_t tpm_get_capability(uint32_t cap_area, uint32_t sub_cap,
> void *cap, size_t count);
>
> +/**
> + * Issue a TPM_FlushSpecific command for a AUTH ressource.
> + *
> + * @param auth_handle handle of the auth session
> + * @return return code of the operation
> + */
> +uint32_t tpm_terminate_auth_session(uint32_t auth_handle);
> +
> +/**
> + * Issue a TPM_OIAP command to setup an object independant authorization
> + * session.
> + * Information about the session is stored internally.
> + * If there was already an OIAP session active it is terminated and a new
> + * session is set up.
> + *
> + * @param auth_handle pointer to the (new) auth handle or NULL.
> + * @return return code of the operation
> + */
> +uint32_t tpm_oiap(uint32_t *auth_handle);
> +
> +/**
> + * Ends an active OIAP session.
> + *
> + * @return return code of the operation
> + */
> +uint32_t tpm_end_oiap(void);
> +
> +/**
> + * Issue a TPM_LoadKey2 (Auth1) command using an OIAP session for authenticating
> + * the usage of the parent key.
> + *
> + * @param parent_handle handle of the parent key.
> + * @param key pointer to the key structure (TPM_KEY or TPM_KEY12).
> + * @param key_length size of the key structure
> + * @param parent_key_usage_auth usage auth for the parent key
> + * @param key_handle pointer to the key handle
> + * @return return code of the operation
> + */
> +uint32_t tpm_load_key2_oiap(uint32_t parent_handle,
> + const void *key, size_t key_length,
> + const void *parent_key_usage_auth,
> + uint32_t *key_handle);
> +
> +/**
> + * Issue a TPM_GetPubKey (Auth1) command using an OIAP session for
> + * authenticating the usage of the key.
> + *
> + * @param key_handle handle of the key
> + * @param usage_auth usage auth for the key
> + * @param pubkey pointer to the pub key buffer; may be NULL if the pubkey
> + * should not be stored.
> + * @param pubkey_len pointer to the pub key buffer len. On entry: the size of
> + * the provided pubkey buffer. On successful exit: the size
> + * of the stored TPM_PUBKEY structure (iff pubkey != NULL).
> + * @return return code of the operation
> + */
> +uint32_t tpm_get_pub_key_oiap(uint32_t key_handle, const void *usage_auth,
> + void *pubkey, size_t *pubkey_len);
> +
> #endif /* __TPM_H */
> diff --git a/lib/tpm.c b/lib/tpm.c
> index 42c9bea..87bf188 100644
> --- a/lib/tpm.c
> +++ b/lib/tpm.c
> @@ -1,5 +1,6 @@
> /*
> * Copyright (c) 2013 The Chromium OS Authors.
> + * Coypright (c) 2013 Guntermann & Drunck GmbH
> *
> * See file CREDITS for list of people who contributed to this
> * project.
> @@ -22,6 +23,7 @@
>
> #include <common.h>
> #include <stdarg.h>
> +#include <sha1.h>
> #include <tpm.h>
> #include <asm/unaligned.h>
>
> @@ -35,8 +37,31 @@ enum {
> TPM_REQUEST_HEADER_LENGTH = 10,
> TPM_RESPONSE_HEADER_LENGTH = 10,
> PCR_DIGEST_LENGTH = 20,
> + DIGEST_LENGTH = 20,
> + TPM_REQUEST_AUTH_LENGTH = 45,
> + TPM_RESPONSE_AUTH_LENGTH = 41,
> + /* some max lengths, valid for RSA keys <= 2048 bits */
> + TPM_KEY12_MAX_LENGTH = 618,
> + TPM_PUBKEY_MAX_LENGTH = 288,
> };
>
> +#ifdef CONFIG_TPM_AUTH_SESSIONS
> +
> +#ifndef CONFIG_SHA1
> +#error "TPM_AUTH_SESSIONS require SHA1 to be configured, too"
> +#endif /* !CONFIG_SHA1 */
> +
> +struct session_data {
> + int valid;
> + uint32_t handle;
> + uint8_t nonce_even[DIGEST_LENGTH];
> + uint8_t nonce_odd[DIGEST_LENGTH];
> +};
> +
> +static struct session_data oiap_session = {0, };
> +
> +#endif /* CONFIG_TPM_AUTH_SESSIONS */
> +
> /**
> * Pack data into a byte string. The data types are specified in
> * the format string: 'b' means unsigned byte, 'w' unsigned word,
> @@ -235,7 +260,7 @@ static uint32_t tpm_sendrecv_command(const void *command,
> response, &response_length);
> if (err)
> return TPM_LIB_ERROR;
> - if (response)
> + if (size_ptr)
> *size_ptr = response_length;
Thanks for catching this!
>
> return tpm_return_code(response);
> @@ -579,3 +604,324 @@ uint32_t tpm_get_capability(uint32_t cap_area, uint32_t sub_cap,
>
> return 0;
> }
> +
> +#ifdef CONFIG_TPM_AUTH_SESSIONS
> +
> +/**
> + * Fill an authentication block in a request.
> + * This func can create the first as well as the second auth block (for
> + * double authorized commands).
> + *
> + * @param request pointer to the request (w/ uninitialised auth data)
> + * @param request_len0 length of the request without auth data
> + * @param handles_len length of the handles area in request
> + * @param auth_session pointer to the (valid) auth session to be used
> + * @param request_auth pointer to the auth block of the request to be filled
> + * @param auth authentication data (HMAC key)
> + */
> +static uint32_t create_request_auth(const void *request, size_t request_len0,
> + size_t handles_len,
> + struct session_data *auth_session,
> + void *request_auth, const void *auth)
> +{
> + uint8_t hmac_data[DIGEST_LENGTH * 3 + 1];
> + sha1_context hash_ctx;
> + const size_t command_code_offset = 6;
> + const size_t auth_nonce_odd_offset = 4;
> + const size_t auth_continue_offset = 24;
> + const size_t auth_auth_offset = 25;
> +
> + if (!auth_session || !auth_session->valid)
> + return TPM_LIB_ERROR;
> +
> + sha1_starts(&hash_ctx);
> + sha1_update(&hash_ctx, request + command_code_offset, 4);
> + if (request_len0 > TPM_REQUEST_HEADER_LENGTH + handles_len)
> + sha1_update(&hash_ctx,
> + request + TPM_REQUEST_HEADER_LENGTH + handles_len,
> + request_len0 - TPM_REQUEST_HEADER_LENGTH - handles_len);
> + sha1_finish(&hash_ctx, hmac_data);
> +
> + sha1_starts(&hash_ctx);
> + sha1_update(&hash_ctx, auth_session->nonce_odd, DIGEST_LENGTH);
> + sha1_update(&hash_ctx, hmac_data, sizeof(hmac_data));
> + sha1_finish(&hash_ctx, auth_session->nonce_odd);
> +
> + if (pack_byte_string(request_auth, TPM_REQUEST_AUTH_LENGTH, "dsb",
> + 0, auth_session->handle,
> + auth_nonce_odd_offset, auth_session->nonce_odd,
> + DIGEST_LENGTH,
> + auth_continue_offset, 1))
> + return TPM_LIB_ERROR;
> + if (pack_byte_string(hmac_data, sizeof(hmac_data), "ss",
> + DIGEST_LENGTH,
> + auth_session->nonce_even,
> + DIGEST_LENGTH,
> + 2 * DIGEST_LENGTH,
> + request_auth + auth_nonce_odd_offset,
> + DIGEST_LENGTH + 1))
> + return TPM_LIB_ERROR;
> + sha1_hmac(auth, DIGEST_LENGTH, hmac_data, sizeof(hmac_data),
> + request_auth + auth_auth_offset);
> +
> + return TPM_SUCCESS;
> +}
> +
> +/**
> + * Verify an authentication block in a response.
> + * Since this func updates the nonce_even in the session data it has to be
> + * called when receiving a succesfull AUTH response.
> + * This func can verify the first as well as the second auth block (for
> + * double authorized commands).
> + *
> + * @param command_code command code of the request
> + * @param response pointer to the request (w/ uninitialised auth data)
> + * @param handles_len length of the handles area in response
> + * @param auth_session pointer to the (valid) auth session to be used
> + * @param response_auth pointer to the auth block of the response to be verified
> + * @param auth authentication data (HMAC key)
> + */
> +static uint32_t verify_response_auth(uint32_t command_code,
> + const void *response, size_t response_len0,
> + size_t handles_len,
> + struct session_data *auth_session,
> + const void *response_auth, const void *auth)
> +{
> + uint8_t hmac_data[DIGEST_LENGTH * 3 + 1];
> + uint8_t computed_auth[DIGEST_LENGTH];
> + sha1_context hash_ctx;
> + const size_t return_code_offset = 6;
> + const size_t auth_continue_offset = 20;
> + const size_t auth_auth_offset = 21;
> + uint8_t auth_continue;
> +
> + if (!auth_session || !auth_session->valid)
> + return TPM_AUTHFAIL;
> + if (pack_byte_string(hmac_data, sizeof(hmac_data), "d",
> + 0, command_code))
> + return TPM_LIB_ERROR;
> + if (response_len0 < TPM_RESPONSE_HEADER_LENGTH)
> + return TPM_LIB_ERROR;
> +
> + sha1_starts(&hash_ctx);
> + sha1_update(&hash_ctx, response + return_code_offset, 4);
> + sha1_update(&hash_ctx, hmac_data, 4);
> + if (response_len0 > TPM_RESPONSE_HEADER_LENGTH + handles_len)
> + sha1_update(&hash_ctx,
> + response + TPM_RESPONSE_HEADER_LENGTH + handles_len,
> + response_len0 - TPM_RESPONSE_HEADER_LENGTH
> + - handles_len);
> + sha1_finish(&hash_ctx, hmac_data);
> +
> + memcpy(auth_session->nonce_even, response_auth, DIGEST_LENGTH);
> + auth_continue = ((uint8_t *)response_auth)[auth_continue_offset];
> + if (pack_byte_string(hmac_data, sizeof(hmac_data), "ssb",
> + DIGEST_LENGTH,
> + response_auth,
> + DIGEST_LENGTH,
> + 2 * DIGEST_LENGTH,
> + auth_session->nonce_odd,
> + DIGEST_LENGTH,
> + 3 * DIGEST_LENGTH,
> + auth_continue))
> + return TPM_LIB_ERROR;
> +
> + sha1_hmac(auth, DIGEST_LENGTH, hmac_data, sizeof(hmac_data),
> + computed_auth);
> +
> + if (memcmp(computed_auth, response_auth + auth_auth_offset,
> + DIGEST_LENGTH))
> + return TPM_AUTHFAIL;
> +
> + return TPM_SUCCESS;
> +}
> +
> +
> +uint32_t tpm_terminate_auth_session(uint32_t auth_handle)
> +{
> + const uint8_t command[18] = {
> + 0x00, 0xc1, /* TPM_TAG */
> + 0x00, 0x00, 0x00, 0x00, /* parameter size */
> + 0x00, 0x00, 0x00, 0xba, /* TPM_COMMAND_CODE */
> + 0x00, 0x00, 0x00, 0x00, /* TPM_HANDLE */
> + 0x00, 0x00, 0x00, 0x02, /* TPM_RESSOURCE_TYPE */
> + };
> + const size_t req_handle_offset = TPM_REQUEST_HEADER_LENGTH;
> + uint8_t request[COMMAND_BUFFER_SIZE];
> +
> + if (pack_byte_string(request, sizeof(request), "sd",
> + 0, command, sizeof(command),
> + req_handle_offset, auth_handle))
> + return TPM_LIB_ERROR;
> + if (oiap_session.valid && oiap_session.handle == auth_handle)
> + oiap_session.valid = 0;
> +
> + return tpm_sendrecv_command(request, NULL, NULL);
> +}
> +
> +uint32_t tpm_end_oiap(void)
> +{
> + uint32_t err = TPM_SUCCESS;
> + if (oiap_session.valid)
> + err = tpm_terminate_auth_session(oiap_session.handle);
> + return err;
> +}
> +
> +uint32_t tpm_oiap(uint32_t *auth_handle)
> +{
> + const uint8_t command[10] = {
> + 0x00, 0xc1, /* TPM_TAG */
> + 0x00, 0x00, 0x00, 0x0a, /* parameter size */
> + 0x00, 0x00, 0x00, 0x0a, /* TPM_COMMAND_CODE */
> + };
> + const size_t res_auth_handle_offset = TPM_RESPONSE_HEADER_LENGTH;
> + const size_t res_nonce_even_offset = TPM_RESPONSE_HEADER_LENGTH + 4;
> + uint8_t response[COMMAND_BUFFER_SIZE];
> + size_t response_length = sizeof(response);
> + uint32_t err;
> +
> + if (oiap_session.valid)
> + tpm_terminate_auth_session(oiap_session.handle);
> +
> + err = tpm_sendrecv_command(command, response, &response_length);
> + if (err)
> + return err;
> + if (unpack_byte_string(response, response_length, "ds",
> + res_auth_handle_offset, &oiap_session.handle,
> + res_nonce_even_offset, &oiap_session.nonce_even,
> + (uint32_t)DIGEST_LENGTH))
> + return TPM_LIB_ERROR;
> + oiap_session.valid = 1;
> + if (auth_handle)
> + *auth_handle = oiap_session.handle;
> + return 0;
> +}
> +
> +uint32_t tpm_load_key2_oiap(uint32_t parent_handle,
> + const void *key, size_t key_length,
> + const void *parent_key_usage_auth,
> + uint32_t *key_handle)
> +{
> + const uint8_t command[14] = {
> + 0x00, 0xc2, /* TPM_TAG */
> + 0x00, 0x00, 0x00, 0x00, /* parameter size */
> + 0x00, 0x00, 0x00, 0x41, /* TPM_COMMAND_CODE */
> + 0x00, 0x00, 0x00, 0x00, /* parent handle */
> + };
> + const size_t req_size_offset = 2;
> + const size_t req_parent_handle_offset = TPM_REQUEST_HEADER_LENGTH;
> + const size_t req_key_offset = TPM_REQUEST_HEADER_LENGTH + 4;
> + const size_t res_handle_offset = TPM_RESPONSE_HEADER_LENGTH;
> + uint8_t request[sizeof(command) + TPM_KEY12_MAX_LENGTH
> + + TPM_REQUEST_AUTH_LENGTH];
> + uint8_t response[COMMAND_BUFFER_SIZE];
> + size_t response_length = sizeof(response);
> + uint32_t err;
> +
> + if (!oiap_session.valid) {
> + err = tpm_oiap(NULL);
> + if (err)
> + return err;
> + }
> + if (pack_byte_string(request, sizeof(request), "sdds",
> + 0, command, sizeof(command),
> + req_size_offset,
> + sizeof(command) + key_length + TPM_REQUEST_AUTH_LENGTH,
> + req_parent_handle_offset, parent_handle,
> + req_key_offset, key, key_length
> + ))
> + return TPM_LIB_ERROR;
> +
> + err = create_request_auth(request, sizeof(command) + key_length, 4,
> + &oiap_session,
> + request + sizeof(command) + key_length,
> + parent_key_usage_auth);
> + if (err)
> + return err;
> + err = tpm_sendrecv_command(request, response, &response_length);
> + if (err) {
> + if (err == TPM_AUTHFAIL)
> + oiap_session.valid = 0;
> + return err;
> + }
> +
> + err = verify_response_auth(0x00000041, response,
> + response_length - TPM_RESPONSE_AUTH_LENGTH,
> + 4, &oiap_session,
> + response + response_length - TPM_RESPONSE_AUTH_LENGTH,
> + parent_key_usage_auth);
> + if (err)
> + return err;
> +
> + if (key_handle) {
> + if (unpack_byte_string(response, response_length, "d",
> + res_handle_offset, key_handle))
> + return TPM_LIB_ERROR;
> + }
> +
> + return 0;
> +}
> +
> +uint32_t tpm_get_pub_key_oiap(uint32_t key_handle, const void *usage_auth,
> + void *pubkey, size_t *pubkey_len)
> +{
> + const uint8_t command[14] = {
> + 0x00, 0xc2, /* TPM_TAG */
> + 0x00, 0x00, 0x00, 0x00, /* parameter size */
> + 0x00, 0x00, 0x00, 0x21, /* TPM_COMMAND_CODE */
> + 0x00, 0x00, 0x00, 0x00, /* key handle */
> + };
> + const size_t req_size_offset = 2;
> + const size_t req_key_handle_offset = TPM_REQUEST_HEADER_LENGTH;
> + const size_t res_pubkey_offset = TPM_RESPONSE_HEADER_LENGTH;
> + uint8_t request[sizeof(command) + TPM_REQUEST_AUTH_LENGTH];
> + uint8_t response[TPM_RESPONSE_HEADER_LENGTH + TPM_PUBKEY_MAX_LENGTH
> + + TPM_RESPONSE_AUTH_LENGTH];
> + size_t response_length = sizeof(response);
> + uint32_t err;
> +
> + if (!oiap_session.valid) {
> + err = tpm_oiap(NULL);
> + if (err)
> + return err;
> + }
> + if (pack_byte_string(request, sizeof(request), "sdd",
> + 0, command, sizeof(command),
> + req_size_offset,
> + (uint32_t)(sizeof(command) + TPM_REQUEST_AUTH_LENGTH),
> + req_key_handle_offset, key_handle
> + ))
> + return TPM_LIB_ERROR;
> + err = create_request_auth(request, sizeof(command), 4, &oiap_session,
> + request + sizeof(command), usage_auth);
> + if (err)
> + return err;
> + err = tpm_sendrecv_command(request, response, &response_length);
> + if (err) {
> + if (err == TPM_AUTHFAIL)
> + oiap_session.valid = 0;
> + return err;
> + }
> + err = verify_response_auth(0x00000021, response,
> + response_length - TPM_RESPONSE_AUTH_LENGTH,
> + 0, &oiap_session,
> + response + response_length - TPM_RESPONSE_AUTH_LENGTH,
> + usage_auth);
> + if (err)
> + return err;
> +
> + if (pubkey) {
> + if ((response_length - TPM_RESPONSE_HEADER_LENGTH
> + - TPM_RESPONSE_AUTH_LENGTH) > *pubkey_len)
> + return TPM_LIB_ERROR;
> + *pubkey_len = response_length - TPM_RESPONSE_HEADER_LENGTH
> + - TPM_RESPONSE_AUTH_LENGTH;
> + memcpy(pubkey, response + res_pubkey_offset,
> + response_length - TPM_RESPONSE_HEADER_LENGTH
> + - TPM_RESPONSE_AUTH_LENGTH);
> + }
> +
> + return 0;
> +}
> +
> +#endif /* CONFIG_TPM_AUTH_SESSIONS */
> --
> 1.7.10.4
>
>
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