1 files changed, 239 insertions, 0 deletions
diff --git a/src/libtpmtss/plugins/tpm/tpm_private_key.c b/src/libtpmtss/plugins/tpm/tpm_private_key.c
new file mode 100644
index 000000000..bd5a8baeb
--- /dev/null
+++ b/src/libtpmtss/plugins/tpm/tpm_private_key.c
@@ -0,0 +1,239 @@
+/*
+ * Copyright (C) 2017 Andreas Steffen
+ * HSR Hochschule fuer Technik Rapperswil
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ */
+
+#include "tpm_private_key.h"
+
+#include <tpm_tss.h>
+#include <utils/debug.h>
+
+typedef struct private_tpm_private_key_t private_tpm_private_key_t;
+
+/**
+ * Private data of an tpm_private_key_t object.
+ */
+struct private_tpm_private_key_t {
+
+	/**
+	 * Public tpm_private_key_t interface.
+	 */
+	tpm_private_key_t public;
+
+	/**
+	 * Token keyid used to reference optional PIN for TPM key
+	 */
+	identification_t *keyid;
+
+	/**
+	 * Trusted Platform Module
+	 */
+	tpm_tss_t *tpm;
+
+	/**
+	 * TPM key object handle
+	 */
+	uint32_t handle;
+
+	/**
+	 * Hierarchy the TPM key object is attached to
+	 */
+	uint32_t hierarchy;
+
+	/**
+	 * Associated public key
+	 */
+	public_key_t *pubkey;
+
+	/**
+	 * References to this key
+	 */
+	refcount_t ref;
+
+};
+
+
+METHOD(private_key_t, get_type, key_type_t,
+	private_tpm_private_key_t *this)
+{
+	return this->pubkey->get_type(this->pubkey);
+}
+
+METHOD(private_key_t, get_keysize, int,
+	private_tpm_private_key_t *this)
+{
+	return this->pubkey->get_keysize(this->pubkey);
+}
+
+METHOD(private_key_t, sign, bool,
+	private_tpm_private_key_t *this, signature_scheme_t scheme,
+	chunk_t data, chunk_t *signature)
+{
+	chunk_t pin = chunk_empty;
+	shared_key_t *shared;
+	enumerator_t *enumerator;
+
+	/* check for optional PIN */
+	enumerator = lib->credmgr->create_shared_enumerator(lib->credmgr,
+										SHARED_PIN, this->keyid, NULL);
+	if (enumerator->enumerate(enumerator, &shared, NULL, NULL))
+	{
+		pin = shared->get_key(shared);
+	}
+	enumerator->destroy(enumerator);
+
+	return this->tpm->sign(this->tpm, this->hierarchy, this->handle, scheme,
+						   data, pin, signature);
+}
+
+METHOD(private_key_t, decrypt, bool,
+	private_tpm_private_key_t *this, encryption_scheme_t scheme,
+	chunk_t crypt, chunk_t *plain)
+{
+	return FALSE;
+}
+
+METHOD(private_key_t, get_public_key, public_key_t*,
+	private_tpm_private_key_t *this)
+{
+	return this->pubkey->get_ref(this->pubkey);
+}
+
+METHOD(private_key_t, get_fingerprint, bool,
+	private_tpm_private_key_t *this, cred_encoding_type_t type,
+	chunk_t *fingerprint)
+{
+	return this->pubkey->get_fingerprint(this->pubkey, type, fingerprint);
+}
+
+METHOD(private_key_t, get_encoding, bool,
+	private_tpm_private_key_t *this, cred_encoding_type_t type,
+	chunk_t *encoding)
+{
+	return FALSE;
+}
+
+METHOD(private_key_t, get_ref, private_key_t*,
+	private_tpm_private_key_t *this)
+{
+	ref_get(&this->ref);
+	return &this->public.key;
+}
+
+METHOD(private_key_t, destroy, void,
+	private_tpm_private_key_t *this)
+{
+	if (ref_put(&this->ref))
+	{
+		DESTROY_IF(this->pubkey);
+		this->tpm->destroy(this->tpm);
+		this->keyid->destroy(this->keyid);
+		free(this);
+	}
+}
+
+/**
+ * See header.
+ */
+tpm_private_key_t *tpm_private_key_connect(key_type_t type, va_list args)
+{
+	private_tpm_private_key_t *this;
+	tpm_tss_t *tpm;
+	chunk_t keyid = chunk_empty, pubkey_blob = chunk_empty;
+	char handle_str[4];
+	size_t len;
+	uint32_t hierarchy = 0x4000000B;  /* TPM_RH_ENDORSEMENT */
+	uint32_t handle;
+
+	while (TRUE)
+	{
+		switch (va_arg(args, builder_part_t))
+		{
+			case BUILD_PKCS11_KEYID:
+				keyid = va_arg(args, chunk_t);
+				continue;
+			case BUILD_PKCS11_SLOT:
+				hierarchy = va_arg(args, int);
+				continue;
+			case BUILD_PKCS11_MODULE:
+				va_arg(args, char*);
+				continue;
+			case BUILD_END:
+				break;
+			default:
+				return NULL;
+		}
+		break;
+	}
+
+	/* convert keyid into 32 bit TPM key object handle */
+	if (!keyid.len)
+	{
+		return NULL;
+	}
+	len = min(keyid.len, 4);
+	memset(handle_str, 0x00, 4);
+	memcpy(handle_str + 4 - len, keyid.ptr + keyid.len - len, len);
+	handle = untoh32(handle_str);
+
+	/* try to find a TPM 2.0 */
+	tpm = tpm_tss_probe(TPM_VERSION_2_0);
+	if (!tpm)
+	{
+		DBG1(DBG_LIB, "no TPM 2.0 found");
+		return NULL;	
+	}
+
+	INIT(this,
+		.public = {
+			.key = {
+				.get_type = _get_type,
+				.sign = _sign,
+				.decrypt = _decrypt,
+				.get_keysize = _get_keysize,
+				.get_public_key = _get_public_key,
+				.equals = private_key_equals,
+				.belongs_to = private_key_belongs_to,
+				.get_fingerprint = _get_fingerprint,
+				.has_fingerprint = private_key_has_fingerprint,
+				.get_encoding = _get_encoding,
+				.get_ref = _get_ref,
+				.destroy = _destroy,
+			},
+		},
+		.tpm = tpm,
+		.keyid = identification_create_from_encoding(ID_KEY_ID, keyid),
+		.handle = handle,
+		.hierarchy = hierarchy,
+		.ref = 1,
+	);
+
+	/* get public key from TPM */
+	pubkey_blob = tpm->get_public(tpm, handle);
+	if (!pubkey_blob.len)
+	{
+		destroy(this);
+		return NULL;
+	}
+	this->pubkey = lib->creds->create(lib->creds, CRED_PUBLIC_KEY, KEY_ANY,
+								BUILD_BLOB_ASN1_DER, pubkey_blob, BUILD_END);
+	chunk_free(&pubkey_blob);
+
+	if (!this->pubkey)
+	{
+		destroy(this);
+		return NULL;
+	}
+
+	return &this->public;
+}