Reference implementation of PKCS#11 URIs

7 files changed, 1089 insertions, 13 deletions

diff --git a/module/Makefile.am b/module/Makefile.am
index 49f0a3d..b4339a8 100644
--- a/module/Makefile.am
+++ b/module/Makefile.am
@@ -4,15 +4,18 @@ incdir = $(includedir)/p11-kit
 
 inc_HEADERS = \
 	p11-kit.h \
+	p11-kit-uri.h \
 	pkcs11.h
 
 MODULE_SRCS = \
 	conf.c conf.h \
 	hash.c hash.h \
+	util.c util.h \
 	p11-kit-lib.c \
 	p11-kit-proxy.c \
 	p11-kit-private.h \
 	p11-kit-messages.c \
+	p11-kit-uri.c \
 	$(inc_HEADERS)
 
 lib_LTLIBRARIES = \
diff --git a/module/p11-kit-proxy.c b/module/p11-kit-proxy.c
index 02f8ac3..3b43a5f 100644
--- a/module/p11-kit-proxy.c
+++ b/module/p11-kit-proxy.c
@@ -39,6 +39,7 @@
 #include "pkcs11.h"
 #include "p11-kit.h"
 #include "p11-kit-private.h"
+#include "util.h"
 
 #include <sys/types.h>
 #include <assert.h>
@@ -87,19 +88,6 @@ static struct _Shared {
 #define LIBRARY_VERSION_MINOR   1
 
 /* -----------------------------------------------------------------------------
- * UTILITIES
- */
-
-static void*
-xrealloc (void * memory, size_t length)
-{
-	void *allocated = realloc (memory, length);
-	if (!allocated)
-		free (memory);
-	return allocated;
-}
-
-/* -----------------------------------------------------------------------------
  * PKCS#11 PROXY MODULE
  */
 
diff --git a/module/p11-kit-uri.c b/module/p11-kit-uri.c
new file mode 100644
index 0000000..8c65301
--- /dev/null
+++ b/module/p11-kit-uri.c
@@ -0,0 +1,886 @@
+/*
+ * Copyright (C) 2011 Collabora Ltd.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *     * Redistributions of source code must retain the above
+ *       copyright notice, this list of conditions and the
+ *       following disclaimer.
+ *     * Redistributions in binary form must reproduce the
+ *       above copyright notice, this list of conditions and
+ *       the following disclaimer in the documentation and/or
+ *       other materials provided with the distribution.
+ *     * The names of contributors to this software may not be
+ *       used to endorse or promote products derived from this
+ *       software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+ * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * Author: Stef Walter <stefw@collabora.co.uk>
+ */
+
+#include "config.h"
+
+#include "pkcs11.h"
+#include "p11-kit-uri.h"
+#include "util.h"
+
+#include <assert.h>
+#include <ctype.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+enum {
+	CLASS_IDX,
+	LABEL_IDX,
+	ID_IDX,
+	NUM_ATTRS,
+};
+
+struct _P11KitUri {
+	int unrecognized;
+	CK_INFO module;
+	CK_TOKEN_INFO token;
+	CK_ATTRIBUTE attrs[NUM_ATTRS];
+};
+
+const static char HEX_CHARS[] = "0123456789abcdef";
+
+static int
+url_decode (const char *value, const char *end,
+            unsigned char** output, size_t *length)
+{
+	char *a, *b;
+	unsigned char *result, *p;
+
+	assert (output);
+	assert (value <= end);
+
+	/* String can only get shorter */
+	result = malloc ((end - value) + 1);
+	if (!result)
+		return P11_KIT_URI_NO_MEMORY;
+
+	/* Now loop through looking for escapes */
+	p = result;
+	while (value != end) {
+		/*
+		 * A percent sign followed by two hex digits means
+		 * that the digits represent an escaped character.
+		 */
+		if (*value == '%') {
+			value++;
+			if (value + 2 > end) {
+				free (result);
+				return P11_KIT_URI_BAD_ENCODING;
+			}
+			a = strchr (HEX_CHARS, tolower (value[0]));
+			b = strchr (HEX_CHARS, tolower (value[1]));
+			if (!a || !b) {
+				free (result);
+				return P11_KIT_URI_BAD_ENCODING;
+			}
+			*p = (a - HEX_CHARS) << 4;
+			*(p++) |= (b - HEX_CHARS);
+			value += 2;
+		} else {
+			*(p++) = *(value++);
+		}
+	}
+
+	*p = 0;
+	if (length)
+		*length = p - result;
+	*output = result;
+	return P11_KIT_URI_OK;
+}
+
+static char*
+url_encode (const unsigned char *value, const unsigned char *end, size_t *length)
+{
+	char *p;
+	char *result;
+
+	assert (value <= end);
+
+	/* Just allocate for worst case */
+	result = malloc (((end - value) * 3) + 1);
+	if (!result)
+		return NULL;
+
+	/* Now loop through looking for escapes */
+	p = result;
+	while (value != end) {
+
+		/* These characters we let through verbatim */
+		if (isalnum (*value) || strchr ("_-.", *value) != NULL) {
+			*(p++) = *(value++);
+
+		/* All others get encoded */
+		} else {
+			*(p++) = '%';
+			*(p++) = HEX_CHARS[((unsigned char)*value) >> 4];
+			*(p++) = HEX_CHARS[((unsigned char)*value) & 0x0F];
+			++value;
+		}
+	}
+
+	*p = 0;
+	if (length)
+		*length = p - result;
+	return result;
+}
+
+static int
+attribute_to_idx (CK_ATTRIBUTE_TYPE type)
+{
+	switch (type) {
+	case CKA_CLASS:
+		return CLASS_IDX;
+	case CKA_LABEL:
+		return LABEL_IDX;
+	case CKA_ID:
+		return ID_IDX;
+	default:
+		return -1;
+	}
+}
+
+static CK_ATTRIBUTE_TYPE
+idx_to_attribute (int idx)
+{
+	switch (idx) {
+	case CLASS_IDX:
+		return CKA_CLASS;
+	case LABEL_IDX:
+		return CKA_LABEL;
+	case ID_IDX:
+		return CKA_ID;
+	default:
+		assert (0);
+	}
+}
+
+static int
+match_struct_string (const unsigned char *inuri, const unsigned char *real,
+                     size_t length)
+{
+	assert (inuri);
+	assert (real);
+	assert (length > 0);
+
+	/* NULL matches anything */
+	if (inuri[0] == 0)
+		return 1;
+
+	return memcmp (inuri, real, length) == 0 ? 1 : 0;
+}
+
+static int
+match_struct_version (CK_VERSION_PTR inuri, CK_VERSION_PTR real)
+{
+	/* This matches anything */
+	if (inuri->major == (CK_BYTE)-1 && inuri->minor == (CK_BYTE)-1)
+		return 1;
+
+	return memcmp (inuri, real, sizeof (CK_VERSION));
+}
+
+CK_INFO_PTR
+p11_kit_uri_get_module_info (P11KitUri *uri)
+{
+	assert (uri);
+	return &uri->module;
+}
+
+int
+p11_kit_uri_match_module_info (P11KitUri *uri, CK_INFO_PTR info)
+{
+	assert (uri);
+	assert (info);
+
+	if (uri->unrecognized)
+		return 0;
+
+	return (match_struct_string (uri->module.libraryDescription,
+	                             info->libraryDescription,
+	                             sizeof (info->libraryDescription)) &&
+	        match_struct_string (uri->module.manufacturerID,
+	                             info->manufacturerID,
+	                             sizeof (info->manufacturerID)) &&
+	        match_struct_version (&uri->module.libraryVersion,
+	                              &info->libraryVersion));
+}
+
+CK_TOKEN_INFO_PTR
+p11_kit_uri_get_token_info (P11KitUri *uri)
+{
+	assert (uri);
+	return &uri->token;
+}
+
+int
+p11_kit_uri_match_token_info (P11KitUri *uri, CK_TOKEN_INFO_PTR token_info)
+{
+	assert (uri);
+	assert (token_info);
+
+	if (uri->unrecognized)
+		return 0;
+
+	return (match_struct_string (uri->token.label,
+	                             token_info->label,
+	                             sizeof (token_info->label)) &&
+	        match_struct_string (uri->token.manufacturerID,
+	                             token_info->manufacturerID,
+	                             sizeof (token_info->manufacturerID)) &&
+	        match_struct_string (uri->token.model,
+	                             token_info->model,
+	                             sizeof (token_info->model)) &&
+	        match_struct_string (uri->token.serialNumber,
+	                             token_info->serialNumber,
+	                             sizeof (token_info->serialNumber)));
+}
+
+CK_ATTRIBUTE_PTR
+p11_kit_uri_get_attribute (P11KitUri *uri, CK_ATTRIBUTE_TYPE type)
+{
+	int idx;
+
+	assert (uri);
+
+	idx = attribute_to_idx (type);
+	if (idx < 0)
+		return NULL;
+
+	assert (idx < NUM_ATTRS);
+	if (uri->attrs[idx].ulValueLen == (CK_ULONG)-1)
+		return NULL;
+	return &uri->attrs[idx];
+}
+
+int
+p11_kit_uri_set_attribute (P11KitUri *uri, CK_ATTRIBUTE_PTR attr)
+{
+	void *value = NULL;
+	int idx;
+	int ret;
+
+	assert (uri);
+	assert (attr);
+
+	if (attr->pValue && attr->ulValueLen && attr->ulValueLen != (CK_ULONG)-1) {
+		value = malloc (attr->ulValueLen);
+		if (!value)
+			return P11_KIT_URI_NO_MEMORY;
+		memcpy (value, attr->pValue, attr->ulValueLen);
+	}
+
+	ret = p11_kit_uri_clear_attribute (uri, attr->type);
+	if (ret < 0){
+		free (value);
+		return ret;
+	}
+
+	idx = attribute_to_idx (attr->type);
+	assert (idx >= 0 && idx < NUM_ATTRS);
+
+	memcpy (&uri->attrs[idx], attr, sizeof (CK_ATTRIBUTE));
+	uri->attrs[idx].pValue = value;
+
+	return P11_KIT_URI_OK;
+}
+
+int
+p11_kit_uri_clear_attribute (P11KitUri *uri, CK_ATTRIBUTE_TYPE type)
+{
+	int idx;
+
+	assert (uri);
+
+	idx = attribute_to_idx (type);
+	if (idx < 0)
+		return P11_KIT_URI_NOT_FOUND;
+	assert (idx < NUM_ATTRS);
+
+	free (uri->attrs[idx].pValue);
+	uri->attrs[idx].pValue = NULL;
+	uri->attrs[idx].ulValueLen = (CK_ULONG)-1;
+	return 0;
+}
+
+static int
+match_attributes (CK_ATTRIBUTE_PTR one, CK_ATTRIBUTE_PTR two)
+{
+	assert (one);
+	assert (two);
+
+	if (one->type != two->type)
+		return 0;
+	if (one->ulValueLen != two->ulValueLen)
+		return 0;
+	if (one->pValue == two->pValue)
+		return 1;
+	if (!one->pValue || !two->pValue)
+		return 0;
+	return memcmp (one->pValue, two->pValue, one->ulValueLen) == 0;
+}
+
+int
+p11_kit_uri_match_attributes (P11KitUri *uri, CK_ATTRIBUTE_PTR attrs,
+                              CK_ULONG n_attrs)
+{
+	CK_ULONG j;
+	int i;
+
+	assert (uri);
+	assert (attrs || !n_attrs);
+
+	if (uri->unrecognized)
+		return 0;
+
+	for (i = 0; i < NUM_ATTRS; ++i) {
+		if (uri->attrs[i].ulValueLen == (CK_ULONG)-1)
+			continue;
+		for (j = 0; j < n_attrs; ++j) {
+			if (attrs[j].type == uri->attrs[i].type) {
+				if (!match_attributes (&uri->attrs[i], &attrs[j]))
+					return 0;
+				break;
+			}
+		}
+	}
+
+	return 1;
+}
+
+void
+p11_kit_uri_set_unrecognized (P11KitUri *uri, int unrecognized)
+{
+	assert (uri);
+	uri->unrecognized = unrecognized;
+}
+
+int
+p11_kit_uri_any_unrecognized (P11KitUri *uri)
+{
+	assert (uri);
+	return uri->unrecognized;
+}
+
+P11KitUri*
+p11_kit_uri_new (void)
+{
+	P11KitUri *uri;
+	int i;
+
+	uri = calloc (1, sizeof (P11KitUri));
+	if (!uri)
+		return NULL;
+
+	/* So that it matches anything */
+	uri->module.libraryVersion.major = (CK_BYTE)-1;
+	uri->module.libraryVersion.minor = (CK_BYTE)-1;
+
+	for (i = 0; i < NUM_ATTRS; ++i) {
+		uri->attrs[i].type = idx_to_attribute (i);
+		uri->attrs[i].ulValueLen = (CK_ULONG)-1;
+	}
+
+	return uri;
+}
+
+static size_t
+space_strlen (const unsigned char *string, size_t max_length)
+{
+	size_t i = max_length - 1;
+
+	assert (string);
+
+	while (i > 0 && string[i] == ' ')
+		--i;
+	return i + 1;
+}
+
+static int
+format_raw_string (char **string, size_t *length, int *is_first,
+                   const char *name, const char *value)
+{
+	size_t namelen;
+	size_t vallen;
+
+	/* Not set */
+	if (!value)
+		return 1;
+
+	namelen = strlen (name);
+	vallen = strlen (value);
+
+	*string = xrealloc (*string, *length + namelen + vallen + 3);
+	if (!*string)
+		return 0;
+
+	if (!*is_first)
+		(*string)[(*length)++] = ';';
+	memcpy ((*string) + *length, name, namelen);
+	*length += namelen;
+	(*string)[(*length)++] = '=';
+	memcpy ((*string) + *length, value, vallen);
+	*length += vallen;
+	(*string)[*length] = 0;
+	*is_first = 0;
+
+	return 1;
+}
+
+
+static int
+format_struct_string (char **string, size_t *length, int *is_first,
+                      const char *name, const unsigned char *value,
+                      size_t value_max)
+{
+	char *encoded;
+	size_t len;
+	int ret;
+
+	/* Not set */
+	if (!value[0])
+		return 1;
+
+	len = space_strlen (value, value_max);
+	encoded = url_encode (value, value + len, NULL);
+	if (!encoded)
+		return 0;
+
+	ret = format_raw_string (string, length, is_first, name, encoded);
+	free (encoded);
+
+	return ret;
+}
+
+static int
+format_attribute_string (char **string, size_t *length, int *is_first,
+                         const char *name, CK_ATTRIBUTE_PTR attr)
+{
+	unsigned char *value;
+	char *encoded;
+	int ret;
+
+	/* Not set */;
+	if (attr->ulValueLen == (CK_ULONG)-1)
+		return 1;
+
+	value = attr->pValue;
+	encoded = url_encode (value, value + attr->ulValueLen, NULL);
+	if (!encoded)
+		return 0;
+
+	ret = format_raw_string (string, length, is_first, name, encoded);
+	free (encoded);
+
+	return ret;
+}
+
+static int
+format_attribute_class (char **string, size_t *length, int *is_first,
+                        const char *name, CK_ATTRIBUTE_PTR attr)
+{
+	CK_OBJECT_CLASS klass;
+	const char *value;
+
+	/* Not set */;
+	if (attr->ulValueLen != sizeof (klass))
+		return 1;
+
+	klass = *((CK_OBJECT_CLASS*)attr->pValue);
+	switch (klass) {
+	case CKO_DATA:
+		value = "data";
+		break;
+	case CKO_SECRET_KEY:
+		value = "secretkey";
+		break;
+	case CKO_CERTIFICATE:
+		value = "cert";
+		break;
+	case CKO_PUBLIC_KEY:
+		value = "public";
+		break;
+	case CKO_PRIVATE_KEY:
+		value = "private";
+		break;
+	}
+
+	return format_raw_string (string, length, is_first, name, value);
+}
+
+static int
+format_struct_version (char **string, size_t *length, int *is_first,
+                       const char *name, CK_VERSION_PTR version)
+{
+	char buffer[64];
+
+	/* Not set */
+	if (version->major == (CK_BYTE)-1 && version->minor == (CK_BYTE)-1)
+		return 1;
+
+	snprintf (buffer, sizeof (buffer), "%d.%d",
+	          (int)version->major, (int)version->minor);
+	return format_raw_string (string, length, is_first, name, buffer);
+}
+
+int
+p11_kit_uri_format (P11KitUri *uri, char **string)
+{
+	char *result = NULL;
+	size_t length = 0;
+	int is_first = 1;
+
+	result = malloc (128);
+	if (!result)
+		return P11_KIT_URI_NO_MEMORY;
+
+	length = P11_KIT_URI_PREFIX_LEN;
+	memcpy (result, P11_KIT_URI_PREFIX, length);
+	result[length] = 0;
+
+	if (!format_struct_string (&result, &length, &is_first, "library-description",
+	                           uri->module.libraryDescription,
+	                           sizeof (uri->module.libraryDescription)) ||
+	    !format_struct_string (&result, &length, &is_first, "library-manufacturer",
+	                           uri->module.manufacturerID,
+	                           sizeof (uri->module.manufacturerID)) ||
+	    !format_struct_string (&result, &length, &is_first, "model",
+	                           uri->token.model,
+	                           sizeof (uri->token.model)) ||
+	    !format_struct_string (&result, &length, &is_first, "manufacturer",
+	                           uri->token.manufacturerID,
+	                           sizeof (uri->token.manufacturerID)) ||
+	    !format_struct_string (&result, &length, &is_first, "serial",
+	                           uri->token.serialNumber,
+	                           sizeof (uri->token.serialNumber)) ||
+	    !format_struct_string (&result, &length, &is_first, "token",
+	                           uri->token.label,
+	                           sizeof (uri->token.label)) ||
+	    !format_struct_version (&result, &length, &is_first, "library-version",
+	                            &uri->module.libraryVersion)) {
+		free (result);
+		return P11_KIT_URI_NO_MEMORY;
+	}
+
+	if (!format_attribute_string (&result, &length, &is_first, "id",
+	                              &uri->attrs[ID_IDX]) ||
+	    !format_attribute_string (&result, &length, &is_first, "object",
+	                              &uri->attrs[LABEL_IDX])) {
+		free (result);
+		return P11_KIT_URI_NO_MEMORY;
+	}
+
+	if (!format_attribute_class (&result, &length, &is_first, "objecttype",
+	                             &uri->attrs[CLASS_IDX])) {
+		free (result);
+		return P11_KIT_URI_NO_MEMORY;
+	}
+
+	*string = result;
+	return P11_KIT_URI_OK;
+}
+
+static int
+parse_string_attribute (const char *name, const char *start, const char *end,
+                        P11KitUri *uri)
+{
+	unsigned char *value;
+	size_t length;
+	int idx, ret;
+
+	assert (start <= end);
+
+	if (strcmp ("id", name) == 0)
+		idx = ID_IDX;
+	else if (strcmp ("object", name) == 0)
+		idx = LABEL_IDX;
+	else
+		return 0;
+
+	ret = url_decode (start, end, &value, &length);
+	if (ret < 0)
+		return ret;
+
+	free (uri->attrs[idx].pValue);
+	uri->attrs[idx].pValue = value;
+	uri->attrs[idx].ulValueLen = length;
+	return 1;
+}
+
+static int
+equals_segment (const char *start, const char *end, const char *match)
+{
+	size_t len = strlen (match);
+	assert (start <= end);
+	return (end - start == len) && memcmp (start, match, len) == 0;
+}
+
+static int
+parse_class_attribute (const char *name, const char *start, const char *end,
+                       P11KitUri *uri)
+{
+	CK_OBJECT_CLASS klass = 0;
+	void *value;
+
+	assert (start <= end);
+
+	if (strcmp ("objecttype", name) != 0)
+		return 0;
+
+	if (equals_segment (start, end, "cert"))
+		klass = CKO_CERTIFICATE;
+	else if (equals_segment (start, end, "public"))
+		klass = CKO_PUBLIC_KEY;
+	else if (equals_segment (start, end, "private"))
+		klass = CKO_PRIVATE_KEY;
+	else if (equals_segment (start, end, "secretkey"))
+		klass = CKO_SECRET_KEY;
+	else if (equals_segment (start, end, "data"))
+		klass = CKO_DATA;
+	else {
+		uri->unrecognized = 1;
+		return 1;
+	}
+
+	value = malloc (sizeof (klass));
+	if (value == NULL)
+		return P11_KIT_URI_NO_MEMORY;
+
+	free (uri->attrs[CLASS_IDX].pValue);
+	memcpy (value, &klass, sizeof (klass));
+	uri->attrs[CLASS_IDX].pValue = value;
+	uri->attrs[CLASS_IDX].ulValueLen = sizeof (klass);
+
+	return 1;
+}
+
+static int
+parse_struct_info (unsigned char *where, size_t length, const char *start,
+                   const char *end, P11KitUri *uri)
+{
+	unsigned char *value;
+	size_t value_length;
+	int ret;
+
+	assert (start <= end);
+
+	ret = url_decode (start, end, &value, &value_length);
+	if (ret < 0)
+		return ret;
+
+	/* Too long, shouldn't match anything */
+	if (value_length > length) {
+		free (value);
+		uri->unrecognized = 1;
+		return 1;
+	}
+
+	memset (where, ' ', length);
+	memcpy (where, value, value_length);
+
+	free (value);
+	return 1;
+}
+
+static int
+parse_token_info (const char *name, const char *start, const char *end,
+                  P11KitUri *uri)
+{
+	unsigned char *where;
+	size_t length;
+
+	assert (start <= end);
+
+	if (strcmp (name, "model") == 0) {
+		where = uri->token.model;
+		length = sizeof (uri->token.model);
+	} else if (strcmp (name, "manufacturer") == 0) {
+		where = uri->token.manufacturerID;
+		length = sizeof (uri->token.manufacturerID);
+	} else if (strcmp (name, "serial") == 0) {
+		where = uri->token.serialNumber;
+		length = sizeof (uri->token.serialNumber);
+	} else if (strcmp (name, "token") == 0) {
+		where = uri->token.label;
+		length = sizeof (uri->token.label);
+	} else {
+		return 0;
+	}
+
+	return parse_struct_info (where, length, start, end, uri);
+}
+
+static int
+atoin (const char *start, const char *end)
+{
+	int ret = 0;
+	while (start != end) {
+		if (*start < '0' || *start > '9')
+			return -1;
+		ret *= 10;
+		ret += (*start - '0');
+		++start;
+	}
+	return ret;
+}
+
+static int
+parse_struct_version (const char *start, const char *end, CK_VERSION_PTR version)
+{
+	const char *dot;
+	int val;
+
+	assert (start <= end);
+
+	dot = memchr (start, '.', end - start);
+	if (!dot)
+		dot = end;
+
+	if (dot == start)
+		return P11_KIT_URI_BAD_VERSION;
+	val = atoin (start, dot);
+	if (val < 0 || val >= 255)
+		return P11_KIT_URI_BAD_VERSION;
+	version->major = (CK_BYTE)val;
+	version->minor = 0;
+
+	if (dot != end) {
+		if (dot + 1 == end)
+			return P11_KIT_URI_BAD_VERSION;
+		val = atoin (dot + 1, end);
+		if (val < 0 || val >= 255)
+			return P11_KIT_URI_BAD_VERSION;
+		version->minor = (CK_BYTE)val;
+	}
+
+	return 1;
+}
+
+static int
+parse_module_info (const char *name, const char *start, const char *end,
+                   P11KitUri *uri)
+{
+	unsigned char *where;
+	size_t length;
+
+	assert (start <= end);
+
+	if (strcmp (name, "library-description") == 0) {
+		where = uri->module.libraryDescription;
+		length = sizeof (uri->module.libraryDescription);
+	} else if (strcmp (name, "library-manufacturer") == 0) {
+		where = uri->module.manufacturerID;
+		length = sizeof (uri->module.manufacturerID);
+	} else if (strcmp (name, "library-version") == 0) {
+		return parse_struct_version (start, end,
+		                             &uri->module.libraryVersion);
+	} else {
+		return 0;
+	}
+
+	return parse_struct_info (where, length, start, end, uri);
+}
+
+int
+p11_kit_uri_parse (const char *string, P11KitUriContext context,
+                   P11KitUri *uri)
+{
+	const char *spos, *epos;
+	char *key = NULL;
+	int ret = -1;
+	int i;
+
+	assert (string);
+	assert (uri);
+
+	if (strncmp (string, P11_KIT_URI_PREFIX, P11_KIT_URI_PREFIX_LEN) != 0)
+		return P11_KIT_URI_BAD_PREFIX;
+
+	string += P11_KIT_URI_PREFIX_LEN;
+
+	/* Clear everything out */
+	memset (&uri->module, 0, sizeof (uri->module));
+	memset (&uri->token, 0, sizeof (uri->module));
+	for (i = 0; i < NUM_ATTRS; ++i)
+		uri->attrs[i].ulValueLen = (CK_ULONG)-1;
+	uri->module.libraryVersion.major = (CK_BYTE)-1;
+	uri->module.libraryVersion.minor = (CK_BYTE)-1;
+	uri->unrecognized = 0;
+
+	for (;;) {
+		spos = strchr (string, ';');
+		if (spos == NULL) {
+			spos = string + strlen (string);
+			assert (*spos == '\0');
+			if (spos == string)
+				break;
+		}
+
+		epos = strchr (string, '=');
+		if (epos == NULL || spos == string || epos == string || epos >= spos)
+			return P11_KIT_URI_BAD_SYNTAX;
+
+		key = malloc ((epos - string) + 1);
+		if (key == NULL)
+			return P11_KIT_URI_NO_MEMORY;
+		memcpy (key, string, epos - string);
+		key[epos - string] = 0;
+		epos++;
+
+		ret = 0;
+		if (context & P11_KIT_URI_PARSE_OBJECT)
+			ret = parse_string_attribute (key, epos, spos, uri);
+		if (ret == 0 && context & P11_KIT_URI_PARSE_OBJECT)
+			ret = parse_class_attribute (key, epos, spos, uri);
+		if (ret == 0 && context & P11_KIT_URI_PARSE_TOKEN)
+			ret = parse_token_info (key, epos, spos, uri);
+		if (ret == 0 && context & P11_KIT_URI_PARSE_MODULE)
+			ret = parse_module_info (key, epos, spos, uri);
+		free (key);
+
+		if (ret < 0)
+			return ret;
+		if (ret == 0)
+			uri->unrecognized = 1;
+
+		if (*spos == '\0')
+			break;
+		string = spos + 1;
+	}
+
+	return P11_KIT_URI_OK;
+}
+
+void
+p11_kit_uri_free (P11KitUri *uri)
+{
+	int i;
+
+	if (!uri)
+		return;
+
+	for (i = 0; i < NUM_ATTRS; ++i)
+		free (uri->attrs[i].pValue);
+
+	free (uri);
+}
diff --git a/module/p11-kit-uri.h b/module/p11-kit-uri.h
new file mode 100644
index 0000000..c5e86bb
--- /dev/null
+++ b/module/p11-kit-uri.h
@@ -0,0 +1,101 @@
+/*
+ * Copyright (c) 2011, Collabora Ltd.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *     * Redistributions of source code must retain the above
+ *       copyright notice, this list of conditions and the
+ *       following disclaimer.
+ *     * Redistributions in binary form must reproduce the
+ *       above copyright notice, this list of conditions and
+ *       the following disclaimer in the documentation and/or
+ *       other materials provided with the distribution.
+ *     * The names of contributors to this software may not be
+ *       used to endorse or promote products derived from this
+ *       software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+ * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * Author: Stef Walter <stefw@collabora.co.uk>
+ */
+
+#include "pkcs11.h"
+
+#ifndef __P11_KIT_URI_H__
+#define __P11_KIT_URI_H__
+
+#define P11_KIT_URI_PREFIX "pkcs11:"
+#define P11_KIT_URI_PREFIX_LEN 7
+
+typedef enum {
+	P11_KIT_URI_OK = 0,
+	P11_KIT_URI_NO_MEMORY = -1,
+	P11_KIT_URI_BAD_PREFIX = -2,
+	P11_KIT_URI_BAD_ENCODING = -3,
+	P11_KIT_URI_BAD_SYNTAX = -4,
+	P11_KIT_URI_BAD_VERSION = -5,
+	P11_KIT_URI_NOT_FOUND = -6,
+} P11KitUriParseStatus;
+
+typedef enum {
+	P11_KIT_URI_PARSE_MODULE = (1 << 1),
+	P11_KIT_URI_PARSE_TOKEN =   (1 << 2) | P11_KIT_URI_PARSE_MODULE,
+	P11_KIT_URI_PARSE_OBJECT =  (1 << 3) | P11_KIT_URI_PARSE_TOKEN,
+	P11_KIT_URI_PARSE_ANY =     0xFFFFFFFF,
+} P11KitUriContext;
+
+typedef struct _P11KitUri P11KitUri;
+
+CK_INFO_PTR         p11_kit_uri_get_module_info             (P11KitUri *uri);
+
+int                 p11_kit_uri_match_module_info           (P11KitUri *uri,
+                                                             CK_INFO_PTR info);
+
+CK_TOKEN_INFO_PTR   p11_kit_uri_get_token_info              (P11KitUri *uri);
+
+int                 p11_kit_uri_match_token_info            (P11KitUri *uri,
+                                                             CK_TOKEN_INFO_PTR token_info);
+
+CK_ATTRIBUTE_PTR    p11_kit_uri_get_attribute               (P11KitUri *uri,
+                                                             CK_ATTRIBUTE_TYPE type);
+
+int                 p11_kit_uri_set_attribute               (P11KitUri *uri,
+                                                             CK_ATTRIBUTE_PTR attr);
+
+int                 p11_kit_uri_clear_attribute             (P11KitUri *uri,
+                                                             CK_ATTRIBUTE_TYPE type);
+
+int                 p11_kit_uri_match_attributes            (P11KitUri *uri,
+                                                             CK_ATTRIBUTE_PTR attrs,
+                                                             CK_ULONG n_attrs);
+
+void                p11_kit_uri_set_unrecognized            (P11KitUri *uri,
+                                                             int unrecognized);
+
+int                 p11_kit_uri_any_unrecognized            (P11KitUri *uri);
+
+P11KitUri*          p11_kit_uri_new                         (void);
+
+int                 p11_kit_uri_format                      (P11KitUri *uri,
+                                                             char **string);
+
+int                 p11_kit_uri_parse                       (const char *string,
+                                                             P11KitUriContext context,
+                                                             P11KitUri *uri);
+
+void                p11_kit_uri_free                        (P11KitUri *uri);
+
+#endif /* __P11_KIT_URI_H__ */
diff --git a/module/p11-kit.h b/module/p11-kit.h
index 50b93d8..25af193 100644
--- a/module/p11-kit.h
+++ b/module/p11-kit.h
@@ -35,6 +35,8 @@
 #ifndef __P11_KIT_H__
 #define __P11_KIT_H__
 
+#include "pkcs11.h"
+
 CK_RV                    p11_kit_initialize_registered     (void);
 
 CK_RV                    p11_kit_finalize_registered       (void);
diff --git a/module/util.c b/module/util.c
new file mode 100644
index 0000000..516e70b
--- /dev/null
+++ b/module/util.c
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2011 Collabora Ltd
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *     * Redistributions of source code must retain the above
+ *       copyright notice, this list of conditions and the
+ *       following disclaimer.
+ *     * Redistributions in binary form must reproduce the
+ *       above copyright notice, this list of conditions and
+ *       the following disclaimer in the documentation and/or
+ *       other materials provided with the distribution.
+ *     * The names of contributors to this software may not be
+ *       used to endorse or promote products derived from this
+ *       software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+ * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ *
+ * CONTRIBUTORS
+ *  Stef Walter <stef@memberwebs.com>
+ */
+
+#include "config.h"
+
+#include "util.h"
+
+#include <stdlib.h>
+
+void*
+xrealloc (void *memory, size_t length)
+{
+	void *allocated = realloc (memory, length);
+	if (!allocated)
+		free (memory);
+	return allocated;
+}
diff --git a/module/util.h b/module/util.h
new file mode 100644
index 0000000..73f06ec
--- /dev/null
+++ b/module/util.h
@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2011 Collabora Ltd
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *     * Redistributions of source code must retain the above
+ *       copyright notice, this list of conditions and the
+ *       following disclaimer.
+ *     * Redistributions in binary form must reproduce the
+ *       above copyright notice, this list of conditions and
+ *       the following disclaimer in the documentation and/or
+ *       other materials provided with the distribution.
+ *     * The names of contributors to this software may not be
+ *       used to endorse or promote products derived from this
+ *       software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+ * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ *
+ * CONTRIBUTORS
+ *  Stef Walter <stef@memberwebs.com>
+ */
+
+#ifndef __UTIL_H__
+#define __UTIL_H__
+
+#include <sys/types.h>
+
+void* xrealloc (void *memory, size_t length);
+
+#endif /* __UTIL_H__ */