1 files changed, 289 insertions, 0 deletions
diff --git a/src/libpts/pts/pts_pcr.c b/src/libpts/pts/pts_pcr.c
new file mode 100644
index 000000000..0af93b608
--- /dev/null
+++ b/src/libpts/pts/pts_pcr.c
@@ -0,0 +1,289 @@
+/*
+ * Copyright (C) 2012 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 "pts_pcr.h"
+
+#include <utils/debug.h>
+
+#include <stdarg.h>
+
+typedef struct private_pts_pcr_t private_pts_pcr_t;
+
+/**
+ * Private data of a pts_pcr_t object.
+ *
+ */
+struct private_pts_pcr_t {
+
+	/**
+	 * Public pts_pcr_t interface.
+	 */
+	pts_pcr_t public;
+
+	/**
+	 * Shadow PCR registers
+	 */
+	chunk_t pcrs[PTS_PCR_MAX_NUM];
+
+	/**
+	 * Number of extended PCR registers
+	 */
+	u_int32_t pcr_count;
+
+	/**
+	 * Highest extended PCR register
+	 */
+	u_int32_t pcr_max;
+
+	/**
+	 * Bitmap of extended PCR registers
+	 */
+	u_int8_t pcr_select[PTS_PCR_MAX_NUM / 8];
+
+	/**
+	 * Hasher used to extend shadow PCRs
+	 */
+	hasher_t *hasher;
+
+};
+
+METHOD(pts_pcr_t, get_count, u_int32_t,
+	private_pts_pcr_t *this)
+{
+	return this->pcr_count;
+}
+
+METHOD(pts_pcr_t, select_pcr, bool,
+	private_pts_pcr_t *this, u_int32_t pcr)
+{
+	u_int32_t i, f;
+
+	if (pcr >= PTS_PCR_MAX_NUM)
+	{
+		DBG1(DBG_PTS, "PCR %2u: number is larger than maximum of %u",
+					   pcr, PTS_PCR_MAX_NUM-1);
+		return FALSE;
+	}
+
+	/* Determine PCR selection flag */
+	i = pcr / 8;
+	f = 1 << (pcr - 8*i);
+
+	/* Has this PCR already been selected? */
+	if (!(this->pcr_select[i] & f))
+	{
+		this->pcr_select[i] |= f;
+		this->pcr_max = max(this->pcr_max, pcr);
+		this->pcr_count++;
+	}
+	return TRUE;
+}
+
+METHOD(pts_pcr_t, get_selection_size, size_t,
+	private_pts_pcr_t *this)
+{
+
+	/**
+	 * A TPM v1.2 has 24 PCR Registers so the bitmask field length
+	 * used by TrouSerS is at least 3 bytes
+	 */
+	return PTS_PCR_MAX_NUM / 8;
+}
+
+typedef struct {
+	/** implements enumerator_t */
+	enumerator_t public;
+	/** current PCR */
+	u_int32_t pcr;
+	/** back reference to parent */
+	private_pts_pcr_t *pcrs;
+} pcr_enumerator_t;
+
+/**
+ * Implementation of enumerator.enumerate
+ */
+static bool pcr_enumerator_enumerate(pcr_enumerator_t *this, ...)
+{
+	u_int32_t *pcr, i, f;
+	va_list args;
+
+	va_start(args, this);
+	pcr = va_arg(args, u_int32_t*);
+	va_end(args);
+
+	while (this->pcr <= this->pcrs->pcr_max)
+	{
+		/* Determine PCR selection flag */
+		i = this->pcr / 8;
+		f = 1 << (this->pcr - 8*i);
+
+		/* Assign current PCR to output argument and increase */
+		*pcr = this->pcr++;
+
+		/* return if PCR is selected */
+		if (this->pcrs->pcr_select[i] & f)
+		{
+			return TRUE;
+		}
+	}
+	return FALSE;
+}
+
+METHOD(pts_pcr_t, create_enumerator, enumerator_t*,
+	private_pts_pcr_t *this)
+{
+	pcr_enumerator_t *enumerator;
+
+	INIT(enumerator,
+		.public = {
+			.enumerate = (void*)pcr_enumerator_enumerate,
+			.destroy = (void*)free,
+		},
+		.pcrs = this,
+	);
+
+	return (enumerator_t*)enumerator;
+}
+
+METHOD(pts_pcr_t, get, chunk_t,
+	private_pts_pcr_t *this, u_int32_t pcr)
+{
+	return (pcr < PTS_PCR_MAX_NUM) ? this->pcrs[pcr] : chunk_empty;
+}
+
+METHOD(pts_pcr_t, set, bool,
+	private_pts_pcr_t *this, u_int32_t pcr, chunk_t value)
+{
+	if (value.len != PTS_PCR_LEN)
+	{
+		DBG1(DBG_PTS, "PCR %2u: value does not fit", pcr);
+		return FALSE;
+	}
+	if (select_pcr(this, pcr))
+	{
+		memcpy(this->pcrs[pcr].ptr, value.ptr, PTS_PCR_LEN);
+		return TRUE;
+	}
+	return FALSE;
+}
+
+METHOD(pts_pcr_t, extend, chunk_t,
+	private_pts_pcr_t *this, u_int32_t pcr, chunk_t measurement)
+{
+	if (measurement.len != PTS_PCR_LEN)
+	{
+		DBG1(DBG_PTS, "PCR %2u: measurement does not fit", pcr);
+		return chunk_empty;
+	}
+	if (!select_pcr(this, pcr))
+	{
+		return chunk_empty;
+	}
+	if (!this->hasher->get_hash(this->hasher, this->pcrs[pcr] , NULL) ||
+		!this->hasher->get_hash(this->hasher, measurement, this->pcrs[pcr].ptr))
+	{
+		DBG1(DBG_PTS, "PCR %2u: not extended due to hasher problem", pcr);
+		return chunk_empty;
+	}
+	return this->pcrs[pcr];
+}
+
+METHOD(pts_pcr_t, get_composite, chunk_t,
+	private_pts_pcr_t *this)
+{
+	chunk_t composite;
+	enumerator_t *enumerator;
+	u_int16_t selection_size;
+	u_int32_t pcr_field_size, pcr;
+	u_char *pos;
+
+	selection_size = get_selection_size(this);
+	pcr_field_size = this->pcr_count * PTS_PCR_LEN;
+
+	composite = chunk_alloc(2 + selection_size + 4 + pcr_field_size);
+	pos = composite.ptr;
+	htoun16(pos, selection_size);
+	pos += 2;
+	memcpy(pos, this->pcr_select, selection_size);
+	pos += selection_size;
+	htoun32(pos, pcr_field_size);
+	pos += 4;
+
+	enumerator = create_enumerator(this);
+	while (enumerator->enumerate(enumerator, &pcr))
+	{
+		memcpy(pos, this->pcrs[pcr].ptr, PTS_PCR_LEN);
+		pos += PTS_PCR_LEN;
+	}
+	enumerator->destroy(enumerator);
+
+	DBG3(DBG_PTS, "constructed PCR Composite: %B", &composite);
+	return composite;
+}
+
+METHOD(pts_pcr_t, destroy, void,
+	private_pts_pcr_t *this)
+{
+	u_int32_t i;
+
+	for (i = 0; i < PTS_PCR_MAX_NUM; i++)
+	{
+		free(this->pcrs[i].ptr);
+	}
+	this->hasher->destroy(this->hasher);
+	free(this);
+}
+
+/**
+ * See header
+ */
+pts_pcr_t *pts_pcr_create(void)
+{
+	private_pts_pcr_t *this;
+	hasher_t *hasher;
+	u_int32_t i;
+
+	hasher = lib->crypto->create_hasher(lib->crypto, HASH_SHA1);
+	if (!hasher)
+	{
+		DBG1(DBG_PTS, "%N hasher could not be created",
+			 hash_algorithm_short_names, HASH_SHA1);
+		return NULL;
+	}
+
+	INIT(this,
+		.public = {
+			.get_count = _get_count,
+			.select_pcr = _select_pcr,
+			.get_selection_size = _get_selection_size,
+			.create_enumerator = _create_enumerator,
+			.get = _get,
+			.set = _set,
+			.extend = _extend,
+			.get_composite = _get_composite,
+			.destroy = _destroy,
+		},
+		.hasher = hasher,
+	);
+
+	for (i = 0; i < PTS_PCR_MAX_NUM; i++)
+	{
+		this->pcrs[i] = chunk_alloc(PTS_PCR_LEN);
+		memset(this->pcrs[i].ptr, 0x00, PTS_PCR_LEN);
+	}
+
+	return &this->public;
+}
+