From: Reinhard Pfau pfau@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 reinhard.pfau@gdsys.cc Signed-off-by: Dirk Eibach dirk.eibach@gdsys.cc Acked-by: Che-Liang Chiou clchiou@chromium.org --- Changes in v7: None Changes in v6: None Changes in v5: None Changes in v4: None Changes in v3: - fix email addresses
Changes in v2: - replace some numeric constants with named constants - style fixes (as shown by checkpatch.pl) in common/cmd_tpm.c and lib/tpm.c
README | 14 +++ common/cmd_tpm.c | 100 ++++++++++++++++ include/tpm.h | 174 +++++++++++++++++++++++++++ lib/tpm.c | 351 ++++++++++++++++++++++++++++++++++++++++++++++++++++++- 4 files changed, 638 insertions(+), 1 deletion(-)
diff --git a/README b/README index cd0336c..3f9a613 100644 --- a/README +++ b/README @@ -1234,6 +1234,20 @@ 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..c34000a 100644 --- a/common/cmd_tpm.c +++ b/common/cmd_tpm.c @@ -27,6 +27,13 @@ #include <asm/unaligned.h> #include <linux/string.h>
+/* Useful constants */ +enum { + DIGEST_LENGTH = 20, + /* max lengths, valid for RSA keys <= 2048 bits */ + TPM_PUBKEY_MAX_LENGTH = 288, +}; + /** * Print a byte string in hexdecimal format, 16-bytes per line. * @@ -546,6 +553,72 @@ 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[DIGEST_LENGTH]; + 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]) != 2 * DIGEST_LENGTH) + 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[DIGEST_LENGTH]; + uint8_t pub_key_buffer[TPM_PUBKEY_MAX_LENGTH]; + 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]) != 2 * DIGEST_LENGTH) + 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 +663,16 @@ 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 +721,16 @@ 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 +741,13 @@ 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..f0b4f59 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;
return tpm_return_code(response); @@ -579,3 +604,327 @@ 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 */