1Tss2_Tcti_Device_Init(3) TPM2 Software Stack Tss2_Tcti_Device_Init(3)
2
6 Tss2_Tcti_Device_init - Initialization function for the device TCTI
7 library.
8
10 #include <tcti/tcti_device.h>
11 TSS2_RC Tss2_Tcti_Device_Init (TSS2_TCTI_CONTEXT *tctiContext, size_t
14 *size, const char *conf);
15 The Tss2_Tcti_Device_Init() function initializes a TCTI context used to
17 communicate with the TPM device driver.
18
20 Tss2_Tcti_Device_Init() attempts to initialize a caller allocated tcti‐
21 Context of size size . Since the tctiContext must be a caller allocated
22 buffer, the caller needs to know the size required by the TCTI library.
23 The minimum size of this context can be discovered by providing NULL
24 for the tctiContext and a non- NULL size parameter. The initialization
25 function will then populate the size parameter with the minimum size of
26 the tctiContext buffer. The caller must then allocate a buffer of this
27 size (or larger) and call Tss2_Tcti_Device_Init () again providing the
28 newly allocated tctiContext and the size of this context in the size
29 parameter. This pattern is common to all TCTI initialization functions.
30 We provide an example of this pattern using the Tss2_Tcti_Device_Init()
31 function in the section titled EXAMPLE.
32 The conf parameter is a C string. If this string is NULL then the
34 library will use a default configuration string for the caller. Alter‐
35 natively, the caller may provide a configuration string that must con‐
36 tain the path to the device node exposed by the TPM device driver.
37 Once initialized, the TCTI context returned exposes the Trusted Comput‐
39 ing Group (TCG) defined API for the lowest level communication with the
40 TPM. Using this API the caller can exchange (send / receive) TPM2 com‐
41 mand and response buffers with the TPM device driver. In nearly all
42 cases however, the caller will initialize a context using this function
43 before passing the context to a higher level API like the System API
44 (SAPI), and then never touch it again.
45 TCG TSS 2.0 TPM Command Transmission Interface (TCTI) API Specification
47 For a more thorough discussion of the TCTI API see the “TCG TSS 2.0 TPM
49 Command Transmission Interface (TCTI) API Specification” as published
50 by the TCG:
51 https://trustedcomputinggroup.org/wp-content/uploads/TSS_TCTI_Version-1.0_Revision-05_Review_END030918.pdf
52
54 A successful call to Tss2_Tcti_Device_Init() will return TSS2_RC_SUC‐
55 CESS. An unsuccessful call will produce a response code described in
56 section ERRORS.
57
59 TSS2_TCTI_RC_BAD_VALUE is returned if any parameters contain unexpected
60 values. TSS2_TCTI_RC_BAD_REFERENCE is returned if any parameters are
61 NULL when they should not be. TSS2_TCTI_RC_BAD_CONTEXT is returned if
62 the size of the provided is insufficient.
63
65 TCTI initialization fragment:
66 #include <inttypes.h>
68 #include <stdlib.h>
69 #include <stdio.h>
70 #include <tcti/tcti_device.h>
71 TSS2_RC rc;
73 TSS2_TCTI_CONTEXT *tcti_context;
74 size_t size;
75 char *conf = "/dev/tpm0",
76 rc = Tss2_Tcti_Device_Init (NULL, &size, NULL);
78 if (rc != TSS2_RC_SUCCESS) {
79 fprintf (stderr, "Failed to get allocation size for device TCTI "
80 " context: 0x%" PRIx32 "0, rc);
81 exit (EXIT_FAILURE);
82 }
83 tcti_context = calloc (1, size);
84 if (tcti_context == NULL) {
85 fprintf (stderr, "Allocation for TCTI context failed: %s0,
86 strerror (errno));
87 exit (EXIT_FAILURE);
88 }
89 rc = Tss2_Tcti_Device_Init (&tcti_context, &size, &conf);
90 if (rc != TSS2_RC_SUCCESS) {
91 fprintf (stderr, "Failed to initialize device TCTI context: "
92 "0x%" PRIx32 "0, rc);
93 free (tcti_context);
94 exit (EXIT_FAILURE);
95 }
96 exit (EXIT_SUCCESS);
97
99 Philip Tricca <philip.b.tricca@intel.com>
100
102 Tss2_Tcti_Device_Init(3), Tss2_Tcti_Socket_Init(3), tcti-device(7),
103 tcti-socket(7), tcti-tabrmd(7), tpm2-abrmd(8)
104
106 This page is part of release 2.2.3 of Intel's implementation of the TCG
107 TPM2 Software Stack (TSS2). A description of the project, information
108 about reporting bugs, and the latest version of this page can be found
109 at https://github.com/01org/tpm2-tss/.
110Intel MARCH 2018 Tss2_Tcti_Device_Init(3)