[U-Boot] [PATCH v6 1/5] tpm: add AUTH1 cmds for LoadKey2 and GetPubKey
dirk.eibach at gdsys.cc
dirk.eibach at gdsys.cc
Wed Jun 12 10:08:02 CEST 2013
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 <reinhard.pfau at gdsys.cc>
Signed-off-by: Dirk Eibach <dirk.eibach at gdsys.cc>
---
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 33bda8c..3d1fa08 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 */
--
1.8.3
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