libtpmss: Configure TCTI device options

diff --git a/conf/plugins/tpm.opt b/conf/plugins/tpm.opt
index 58f5d8b354600bd8455f5900f966017165e2aa9d..df7adb0984501392a9bc23e86c02aceb4fe48b30 100644 (file)
--- a/conf/plugins/tpm.opt
+++ b/conf/plugins/tpm.opt
@@ -1,5 +1,12 @@
 charon.plugins.tpm.use_rng = no
        Whether the TPM should be used as RNG.
 
-charon.plugins.tpm.tcti.name = tabrmd
-       Name of TCTI library. Valid values: tabrmd, device, mssim.
\ No newline at end of file
+charon.plugins.tpm.tcti.name = device|tabrmd
+       Name of TPM 2.0 TCTI library. Valid values: _tabrmd_, _device_ or _mssim_.
+       Defaults are _device_ if the _/dev/tpmrm0_ in-kernel TPM 2.0 resource manager
+       device exists, and _tabrmd_ otherwise, requiring the d-bus based TPM 2.0
+       access broker and resource manager to be available.
+
+charon.plugins.tpm.tcti.opts = /dev/tpmrm0|<none>
+       Options for the TPM 2.0 TCTI library. Defaults are _/dev/tpmrm0_ if the
+       TCTI library name is _device_ and no options otherwise.

diff --git a/src/libtpmtss/tpm_tss_tss2_v2.c b/src/libtpmtss/tpm_tss_tss2_v2.c
index 18164f08b449ef437362412e78d5016859d5ddc2..7cb0d48a91c046e52fbad84fda18e41c1aac7c41 100644 (file)
--- a/src/libtpmtss/tpm_tss_tss2_v2.c
+++ b/src/libtpmtss/tpm_tss_tss2_v2.c
@@ -23,7 +23,11 @@
 #include <bio/bio_reader.h>
 
 #include <tss2/tss2_sys.h>
+
 #include <dlfcn.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
 
 #define LABEL  "TPM 2.0 -"
 
@@ -69,6 +73,8 @@ static void *tcti_handle;
 
 static TSS2_TCTI_INIT_FUNC tcti_init;
 
+static char *tcti_opts;
+
 /**
  * Empty AUTH_COMMAND
  */
@@ -268,7 +274,7 @@ static bool initialize_tcti_context(private_tpm_tss_tss2_t *this)
        }
 
        /* determine size of tcti context */
-       rval = tcti_init(NULL, &tcti_context_size, "");
+       rval = tcti_init(NULL, &tcti_context_size, tcti_opts);
        if (rval != TSS2_RC_SUCCESS)
        {
                DBG1(DBG_PTS, "%s tcti init setup failed: 0x%06x",  LABEL, rval);
@@ -280,13 +286,13 @@ static bool initialize_tcti_context(private_tpm_tss_tss2_t *this)
        memset(this->tcti_context, 0x00, tcti_context_size);
 
        /* initialize tcti context */
-       rval = tcti_init(this->tcti_context, &tcti_context_size, "");
+       rval = tcti_init(this->tcti_context, &tcti_context_size, tcti_opts);
        if (rval != TSS2_RC_SUCCESS)
        {
                DBG1(DBG_PTS, "%s tcti init allocation failed: 0x%06x", LABEL,rval);
                return FALSE;
        }
-       return TRUE;            
+       return TRUE;
 }
 
 /**
@@ -1089,14 +1095,24 @@ bool tpm_tss_tss2_init(void)
        const TSS2_TCTI_INFO *info;
        char tcti_lib_format[] = "libtss2-tcti-%s.so.0";
        char tcti_lib[BUF_LEN];
-       char *tcti_names[] = { "tabrmd", "device", "mssim" };
+       char *tcti_names[]   = { "device", "tabrmd", "mssim" };
+       char *tcti_options[] = { "/dev/tpmrm0", "", "" };
        char *tcti_name;
        bool match = FALSE;
-       int i;
+       struct stat st;
+       int i = 0;
 
-       /* select a dynamic TCTI library */
+       /* check for the existence of an in-kernel TPM resource manager */
+       if (stat(tcti_options[i], &st))
+       {
+               i = 1;
+       }
+       DBG2(DBG_PTS, "%s \"%s\" in-kernel resource manager is %spresent",
+                                  LABEL, tcti_options[0], i ? "not " : "");
+
+       /* select a dynamic TCTI library (device, tabrmd or mssim) */
        tcti_name = lib->settings->get_str(lib->settings,
-                                        "%s.plugins.tpm.tcti.name", tcti_names[0], lib->ns);
+                                        "%s.plugins.tpm.tcti.name", tcti_names[i], lib->ns);
        snprintf(tcti_lib, BUF_LEN, tcti_lib_format, tcti_name);
 
        for (i = 0; i < countof(tcti_names); i++)
@@ -1104,6 +1120,7 @@ bool tpm_tss_tss2_init(void)
                if (streq(tcti_name, tcti_names[i]))
                {
                        match = TRUE;
+                       break;
                }
        }
        if (!match)
@@ -1113,6 +1130,9 @@ bool tpm_tss_tss2_init(void)
                return FALSE;
        }
 
+       tcti_opts = lib->settings->get_str(lib->settings,
+                                        "%s.plugins.tpm.tcti.opts", tcti_options[i], lib->ns);
+
        /* open the selected dynamic TCTI library */
        tcti_handle = dlopen(tcti_lib, RTLD_LAZY);
        if (!tcti_handle)
@@ -1143,7 +1163,9 @@ bool tpm_tss_tss2_init(void)
 void tpm_tss_tss2_deinit(void)
 {
        dlclose(tcti_handle);
-       tcti_handle = tcti_init = NULL;
+       tcti_handle = NULL;
+       tcti_init   = NULL;
+       tcti_opts   = NULL;
 }
 
 #else /* TSS_TSS2_V2 */