Refactor how parsing of ASN.1 data and certificate extensions work

9 files changed, 1135 insertions, 3 deletions

diff --git a/common/Makefile.am b/common/Makefile.am
index bed4630..145627c 100644
--- a/common/Makefile.am
+++ b/common/Makefile.am
@@ -39,12 +39,14 @@ noinst_LTLIBRARIES += \
 	$(NULL)
 
 libp11_data_la_SOURCES = \
+	asn1.c asn1.h \
 	base64.c base64.h \
 	checksum.c checksum.h \
 	oid.c oid.h \
 	openssl.asn openssl.asn.h \
 	pem.c pem.h \
 	pkix.asn pkix.asn.h \
+	x509.c x509.h \
 	$(NULL)
 
 asn:
diff --git a/common/asn1.c b/common/asn1.c
new file mode 100644
index 0000000..3df56d9
--- /dev/null
+++ b/common/asn1.c
@@ -0,0 +1,551 @@
+/*
+ * Copyright (C) 2012 Red Hat Inc.
+ *
+ * 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@redhat.com>
+ */
+
+#include "config.h"
+
+#include "asn1.h"
+#define P11_DEBUG_FLAG P11_DEBUG_TRUST
+#include "debug.h"
+#include "oid.h"
+
+#include "openssl.asn.h"
+#include "pkix.asn.h"
+
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+
+static void
+free_asn1_def (void *data)
+{
+	node_asn *def = data;
+	asn1_delete_structure (&def);
+}
+
+struct {
+	const ASN1_ARRAY_TYPE* tab;
+	const char *prefix;
+	int prefix_len;
+} asn1_tabs[] = {
+	{ pkix_asn1_tab, "PKIX1.", 6 },
+	{ openssl_asn1_tab, "OPENSSL.", 8 },
+	{ NULL, },
+};
+
+p11_dict *
+p11_asn1_defs_load (void)
+{
+	char message[ASN1_MAX_ERROR_DESCRIPTION_SIZE] = { 0, };
+	node_asn *def;
+	p11_dict *defs;
+	int ret;
+	int i;
+
+	defs = p11_dict_new (p11_dict_str_hash, p11_dict_str_equal, NULL, free_asn1_def);
+
+	for (i = 0; asn1_tabs[i].tab != NULL; i++) {
+
+		def = NULL;
+		ret = asn1_array2tree (asn1_tabs[i].tab, &def, message);
+		if (ret != ASN1_SUCCESS) {
+			p11_debug_precond ("failed to load %s* definitions: %s: %s\n",
+			                   asn1_tabs[i].prefix, asn1_strerror (ret), message);
+			return NULL;
+		}
+
+		if (!p11_dict_set (defs, (void *)asn1_tabs[i].prefix, def))
+			return_val_if_reached (NULL);
+	}
+
+	return defs;
+}
+
+static node_asn *
+lookup_def (p11_dict *asn1_defs,
+            const char *struct_name)
+{
+	int i;
+
+	for (i = 0; asn1_tabs[i].tab != NULL; i++) {
+		if (strncmp (struct_name, asn1_tabs[i].prefix, asn1_tabs[i].prefix_len) == 0)
+			return p11_dict_get (asn1_defs, asn1_tabs[i].prefix);
+	}
+
+	p11_debug_precond ("unknown prefix for element: %s\n", struct_name);
+	return NULL;
+}
+
+node_asn *
+p11_asn1_create (p11_dict *asn1_defs,
+                 const char *struct_name)
+{
+	node_asn *def;
+	node_asn *asn;
+	int ret;
+
+	return_val_if_fail (asn1_defs != NULL, NULL);
+
+	def = lookup_def (asn1_defs, struct_name);
+	return_val_if_fail (def != NULL, NULL);
+
+	ret = asn1_create_element (def, struct_name, &asn);
+	if (ret != ASN1_SUCCESS) {
+		p11_debug_precond ("failed to create element %s: %s\n",
+		                   struct_name, asn1_strerror (ret));
+		return NULL;
+	}
+
+	return asn;
+}
+
+node_asn *
+p11_asn1_decode (p11_dict *asn1_defs,
+                 const char *struct_name,
+                 const unsigned char *der,
+                 size_t der_len,
+                 char *message)
+{
+	char msg[ASN1_MAX_ERROR_DESCRIPTION_SIZE];
+	node_asn *asn = NULL;
+	int ret;
+
+	return_val_if_fail (asn1_defs != NULL, NULL);
+
+	if (message == NULL)
+		message = msg;
+
+	asn = p11_asn1_create (asn1_defs, struct_name);
+	return_val_if_fail (asn != NULL, NULL);
+
+	/* asn1_der_decoding destroys the element if fails */
+	ret = asn1_der_decoding (&asn, der, der_len, message);
+
+	if (ret != ASN1_SUCCESS) {
+		p11_debug ("couldn't parse %s: %s: %s",
+		           struct_name, asn1_strerror (ret), message);
+		return NULL;
+	}
+
+	return asn;
+}
+
+unsigned char *
+p11_asn1_encode (node_asn *asn,
+                 size_t *der_len)
+{
+	char message[ASN1_MAX_ERROR_DESCRIPTION_SIZE];
+	struct asn1_data_node data = { NULL, };
+	unsigned char *der;
+	int len;
+	int ret;
+
+	return_val_if_fail (der_len != NULL, NULL);
+
+	len = 0;
+	ret = asn1_der_coding (asn, "", NULL, &len, message);
+	return_val_if_fail (ret != ASN1_SUCCESS, NULL);
+
+	if (ret == ASN1_MEM_ERROR) {
+		der = malloc (len);
+		return_val_if_fail (der != NULL, NULL);
+
+		ret = asn1_der_coding (asn, "", der, &len, message);
+	}
+
+	if (ret != ASN1_SUCCESS) {
+		asn1_read_node_value (asn, &data);
+		p11_debug_precond ("failed to encode %s: %s\n",
+		                   data.name ? data.name : "(unknown)", message);
+		return NULL;
+	}
+
+	if (der_len)
+		*der_len = len;
+	return der;
+}
+
+static int
+atoin (const char *p,
+       int digits)
+{
+	int ret = 0, base = 1;
+	while(--digits >= 0) {
+		if (p[digits] < '0' || p[digits] > '9')
+			return -1;
+		ret += (p[digits] - '0') * base;
+		base *= 10;
+	}
+	return ret;
+}
+
+static int
+two_to_four_digit_year (int year)
+{
+	time_t now;
+	struct tm tm;
+	int century, current;
+
+	return_val_if_fail (year >= 0 && year <= 99, -1);
+
+	/* Get the current year */
+	now = time (NULL);
+	return_val_if_fail (now >= 0, -1);
+	if (!gmtime_r (&now, &tm))
+		return_val_if_reached (-1);
+
+	current = (tm.tm_year % 100);
+	century = (tm.tm_year + 1900) - current;
+
+	/*
+	 * Check if it's within 40 years before the
+	 * current date.
+	 */
+	if (current < 40) {
+		if (year < current)
+			return century + year;
+		if (year > 100 - (40 - current))
+			return (century - 100) + year;
+	} else {
+		if (year < current && year > (current - 40))
+			return century + year;
+	}
+
+	/*
+	 * If it's after then adjust for overflows to
+	 * the next century.
+	 */
+	if (year < current)
+		return century + 100 + year;
+	else
+		return century + year;
+}
+
+static int
+parse_utc_time (const char *time,
+                size_t n_time,
+                struct tm *when,
+                int *offset)
+{
+	const char *p, *e;
+	int year;
+
+	assert (when != NULL);
+	assert (time != NULL);
+	assert (offset != NULL);
+
+	/* YYMMDDhhmmss.ffff Z | +0000 */
+	if (n_time < 6 || n_time >= 28)
+		return 0;
+
+	/* Reset everything to default legal values */
+	memset (when, 0, sizeof (*when));
+	*offset = 0;
+	when->tm_mday = 1;
+
+	/* Select the digits part of it */
+	p = time;
+	for (e = p; *e >= '0' && *e <= '9'; ++e);
+
+	if (p + 2 <= e) {
+		year = atoin (p, 2);
+		p += 2;
+
+		/*
+		 * 40 years in the past is our century. 60 years
+		 * in the future is the next century.
+		 */
+		when->tm_year = two_to_four_digit_year (year) - 1900;
+	}
+	if (p + 2 <= e) {
+		when->tm_mon = atoin (p, 2) - 1;
+		p += 2;
+	}
+	if (p + 2 <= e) {
+		when->tm_mday = atoin (p, 2);
+		p += 2;
+	}
+	if (p + 2 <= e) {
+		when->tm_hour = atoin (p, 2);
+		p += 2;
+	}
+	if (p + 2 <= e) {
+		when->tm_min = atoin (p, 2);
+		p += 2;
+	}
+	if (p + 2 <= e) {
+		when->tm_sec = atoin (p, 2);
+		p += 2;
+	}
+
+	if (when->tm_year < 0 || when->tm_year > 9999 ||
+	    when->tm_mon < 0 || when->tm_mon > 11 ||
+	    when->tm_mday < 1 || when->tm_mday > 31 ||
+	    when->tm_hour < 0 || when->tm_hour > 23 ||
+	    when->tm_min < 0 || when->tm_min > 59 ||
+	    when->tm_sec < 0 || when->tm_sec > 59)
+		return 0;
+
+	/* Make sure all that got parsed */
+	if (p != e)
+		return 0;
+
+	/* Now the remaining optional stuff */
+	e = time + n_time;
+
+	/* See if there's a fraction, and discard it if so */
+	if (p < e && *p == '.' && p + 5 <= e)
+		p += 5;
+
+	/* See if it's UTC */
+	if (p < e && *p == 'Z') {
+		p += 1;
+
+	/* See if it has a timezone */
+	} else if ((*p == '-' || *p == '+') && p + 3 <= e) {
+		int off, neg;
+
+		neg = *p == '-';
+		++p;
+
+		off = atoin (p, 2) * 3600;
+		if (off < 0 || off > 86400)
+			return 0;
+		p += 2;
+
+		if (p + 2 <= e) {
+			off += atoin (p, 2) * 60;
+			p += 2;
+		}
+
+		/* Use TZ offset */
+		if (neg)
+			*offset = 0 - off;
+		else
+			*offset = off;
+	}
+
+	/* Make sure everything got parsed */
+	if (p != e)
+		return 0;
+
+	return 1;
+}
+
+static int
+parse_general_time (const char *time,
+                    size_t n_time,
+                    struct tm *when,
+                    int *offset)
+{
+	const char *p, *e;
+
+	assert (time != NULL);
+	assert (when != NULL);
+	assert (offset != NULL);
+
+	/* YYYYMMDDhhmmss.ffff Z | +0000 */
+	if (n_time < 8 || n_time >= 30)
+		return 0;
+
+	/* Reset everything to default legal values */
+	memset (when, 0, sizeof (*when));
+	*offset = 0;
+	when->tm_mday = 1;
+
+	/* Select the digits part of it */
+	p = time;
+	for (e = p; *e >= '0' && *e <= '9'; ++e);
+
+	if (p + 4 <= e) {
+		when->tm_year = atoin (p, 4) - 1900;
+		p += 4;
+	}
+	if (p + 2 <= e) {
+		when->tm_mon = atoin (p, 2) - 1;
+		p += 2;
+	}
+	if (p + 2 <= e) {
+		when->tm_mday = atoin (p, 2);
+		p += 2;
+	}
+	if (p + 2 <= e) {
+		when->tm_hour = atoin (p, 2);
+		p += 2;
+	}
+	if (p + 2 <= e) {
+		when->tm_min = atoin (p, 2);
+		p += 2;
+	}
+	if (p + 2 <= e) {
+		when->tm_sec = atoin (p, 2);
+		p += 2;
+	}
+
+	if (when->tm_year < 0 || when->tm_year > 9999 ||
+	    when->tm_mon < 0 || when->tm_mon > 11 ||
+	    when->tm_mday < 1 || when->tm_mday > 31 ||
+	    when->tm_hour < 0 || when->tm_hour > 23 ||
+	    when->tm_min < 0 || when->tm_min > 59 ||
+	    when->tm_sec < 0 || when->tm_sec > 59)
+		return 0;
+
+	/* Make sure all that got parsed */
+	if (p != e)
+		return 0;
+
+	/* Now the remaining optional stuff */
+	e = time + n_time;
+
+	/* See if there's a fraction, and discard it if so */
+	if (p < e && *p == '.' && p + 5 <= e)
+		p += 5;
+
+	/* See if it's UTC */
+	if (p < e && *p == 'Z') {
+		p += 1;
+
+	/* See if it has a timezone */
+	} else if ((*p == '-' || *p == '+') && p + 3 <= e) {
+		int off, neg;
+
+		neg = *p == '-';
+		++p;
+
+		off = atoin (p, 2) * 3600;
+		if (off < 0 || off > 86400)
+			return 0;
+		p += 2;
+
+		if (p + 2 <= e) {
+			off += atoin (p, 2) * 60;
+			p += 2;
+		}
+
+		/* Use TZ offset */
+		if (neg)
+			*offset = 0 - off;
+		else
+			*offset = off;
+	}
+
+	/* Make sure everything got parsed */
+	if (p != e)
+		return 0;
+
+	return 1;
+}
+
+static time_t
+when_and_offset_to_time_t (struct tm *when,
+                           int tz_offset)
+{
+	time_t timet;
+
+	/* In order to work with 32 bit time_t. */
+	if (sizeof (time_t) <= 4 && when->tm_year >= 2038) {
+		timet = (time_t)2145914603;  /* 2037-12-31 23:23:23 */
+
+	/* Convert to seconds since epoch */
+	} else {
+		timet = timegm (when);
+		return_val_if_fail (timet >= 0, -1);
+		timet += tz_offset;
+	}
+
+	if (!gmtime_r (&timet, when))
+		return_val_if_reached (-1);
+
+	return timet;
+}
+
+time_t
+p11_asn1_parse_utc (const char *time_str,
+                    struct tm *when)
+{
+	struct tm dummy;
+	int tz_offset;
+	int ret;
+
+	if (!when)
+		when = &dummy;
+
+	ret = parse_utc_time (time_str, strlen (time_str),
+	                      when, &tz_offset);
+	if (!ret)
+		return -1;
+
+	return when_and_offset_to_time_t (when, tz_offset);
+}
+
+time_t
+p11_asn1_parse_general (const char *time_str,
+                        struct tm *when)
+{
+	struct tm dummy;
+	int tz_offset;
+	int ret;
+
+	if (!when)
+		when = &dummy;
+
+	ret = parse_general_time (time_str, strlen (time_str),
+	                          when, &tz_offset);
+	if (!ret)
+		return -1;
+
+	return when_and_offset_to_time_t (when, tz_offset);
+}
+
+ssize_t
+p11_asn1_tlv_length (const unsigned char *data,
+                     size_t length)
+{
+	unsigned char cls;
+	int counter = 0;
+	int cb, len;
+	unsigned long tag;
+
+	if (asn1_get_tag_der (data, length, &cls, &cb, &tag) == ASN1_SUCCESS) {
+		counter += cb;
+		len = asn1_get_length_der (data + cb, length - cb, &cb);
+		counter += cb;
+		if (len >= 0) {
+			len += counter;
+			if (length >= len)
+				return len;
+		}
+	}
+
+	return -1;
+}
diff --git a/common/asn1.h b/common/asn1.h
new file mode 100644
index 0000000..76a84ed
--- /dev/null
+++ b/common/asn1.h
@@ -0,0 +1,65 @@
+/*
+ * Copyright (C) 2012 Red Hat Inc.
+ *
+ * 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@redhat.com>
+ */
+
+#include <libtasn1.h>
+
+#include "dict.h"
+
+#ifndef P11_ASN1_H_
+#define P11_ASN1_H_
+
+p11_dict *       p11_asn1_defs_load                 (void);
+
+node_asn *       p11_asn1_decode                    (p11_dict *asn1_defs,
+                                                     const char *struct_name,
+                                                     const unsigned char *der,
+                                                     size_t der_len,
+                                                     char *message);
+
+node_asn *       p11_asn1_create                    (p11_dict *asn1_defs,
+                                                     const char *struct_name);
+
+unsigned char *  p11_asn1_encode                    (node_asn *asn,
+                                                     size_t *der_len);
+
+time_t           p11_asn1_parse_utc                 (const char *time_str,
+                                                     struct tm *when);
+
+time_t           p11_asn1_parse_general             (const char *time_str,
+                                                     struct tm *when);
+
+ssize_t          p11_asn1_tlv_length                (const unsigned char *data,
+                                                     size_t length);
+
+#endif /* P11_ASN1_H_ */
diff --git a/common/oid.h b/common/oid.h
index 181539a..a06054a 100644
--- a/common/oid.h
+++ b/common/oid.h
@@ -129,6 +129,7 @@ static const unsigned char P11_OID_OPENSSL_REJECT[] =
  */
 static const unsigned char P11_OID_SERVER_AUTH[] =
 	{ 0x06, 0x08, 0x2b, 0x06, 0x01, 0x05, 0x05, 0x07, 0x03, 0x01 };
+static const char P11_OID_SERVER_AUTH_STR[] = "1.3.6.1.5.5.7.3.1";
 
 /*
  * 1.3.6.1.5.5.7.3.2: Client Auth
@@ -137,6 +138,7 @@ static const unsigned char P11_OID_SERVER_AUTH[] =
  */
 static const unsigned char P11_OID_CLIENT_AUTH[] =
 	{ 0x06, 0x08, 0x2b, 0x06, 0x01, 0x05, 0x05, 0x07, 0x03, 0x02 };
+static const char P11_OID_CLIENT_AUTH_STR[] = "1.3.6.1.5.5.7.3.2";
 
 /*
  * 1.3.6.1.5.5.7.3.3: Code Signing
@@ -145,6 +147,7 @@ static const unsigned char P11_OID_CLIENT_AUTH[] =
  */
 static const unsigned char P11_OID_CODE_SIGNING[] =
 	{ 0x06, 0x08, 0x2b, 0x06, 0x01, 0x05, 0x05, 0x07, 0x03, 0x03 };
+static const char P11_OID_CODE_SIGNING_STR[] = "1.3.6.1.5.5.7.3.3";
 
 /*
  * 1.3.6.1.5.5.7.3.4: Email Protection
@@ -153,6 +156,7 @@ static const unsigned char P11_OID_CODE_SIGNING[] =
  */
 static const unsigned char P11_OID_EMAIL_PROTECTION[] =
 	{ 0x06, 0x08, 0x2b, 0x06, 0x01, 0x05, 0x05, 0x07, 0x03, 0x04 };
+static const char P11_OID_EMAIL_PROTECTION_STR[] = "1.3.6.1.5.5.7.3.4";
 
 /*
  * 1.3.6.1.5.5.7.3.5: IPSec End System
@@ -161,6 +165,7 @@ static const unsigned char P11_OID_EMAIL_PROTECTION[] =
  */
 static const unsigned char P11_OID_IPSEC_END_SYSTEM[] =
 	{ 0x06, 0x08, 0x2b, 0x06, 0x01, 0x05, 0x05, 0x07, 0x03, 0x05 };
+static const char P11_OID_IPSEC_END_SYSTEM_STR[] = "1.3.6.1.5.5.7.3.5";
 
 /*
  * 1.3.6.1.5.5.7.3.6: IPSec Tunnel
@@ -169,6 +174,7 @@ static const unsigned char P11_OID_IPSEC_END_SYSTEM[] =
  */
 static const unsigned char P11_OID_IPSEC_TUNNEL[] =
 	{ 0x06, 0x08, 0x2b, 0x06, 0x01, 0x05, 0x05, 0x07, 0x03, 0x06 };
+static const char P11_OID_IPSEC_TUNNEL_STR[] = "1.3.6.1.5.5.7.3.6";
 
 /*
  * 1.3.6.1.5.5.7.3.7: IPSec User
@@ -177,6 +183,7 @@ static const unsigned char P11_OID_IPSEC_TUNNEL[] =
  */
 static const unsigned char P11_OID_IPSEC_USER[] =
 	{ 0x06, 0x08, 0x2b, 0x06, 0x01, 0x05, 0x05, 0x07, 0x03, 0x07 };
+static const char P11_OID_IPSEC_USER_STR[] = "1.3.6.1.5.5.7.3.7";
 
 /*
  * 1.3.6.1.5.5.7.3.8: Time Stamping
@@ -185,7 +192,7 @@ static const unsigned char P11_OID_IPSEC_USER[] =
  */
 static const unsigned char P11_OID_TIME_STAMPING[] =
 	{ 0x06, 0x08, 0x2b, 0x06, 0x01, 0x05, 0x05, 0x07, 0x03, 0x08 };
-
+static const char P11_OID_TIME_STAMPING_STR[] = "1.3.6.1.5.5.7.3.8";
 /*
  * 1.3.6.1.4.1.3319.6.10.16: Reserved key purpose
  *
@@ -202,7 +209,6 @@ static const unsigned char P11_OID_TIME_STAMPING[] =
  */
 static const unsigned char P11_OID_RESERVED_PURPOSE[] =
 	{ 0x06, 0x0a, 0x2b, 0x06, 0x01, 0x04, 0x01, 0x99, 0x77, 0x06, 0x0a, 0x10 };
-static const char P11_OID_RESERVED_PURPOSE_STR[] =
-	"1.3.6.1.4.1.3319.6.10.16";
+static const char P11_OID_RESERVED_PURPOSE_STR[] = "1.3.6.1.4.1.3319.6.10.16";
 
 #endif
diff --git a/common/tests/Makefile.am b/common/tests/Makefile.am
index 94c6556..6d8d76e 100644
--- a/common/tests/Makefile.am
+++ b/common/tests/Makefile.am
@@ -34,9 +34,11 @@ LDADD += \
 	$(NULL)
 
 CHECK_PROGS += \
+	test-asn1 \
 	test-checksum \
 	test-pem \
 	test-oid \
+	test-x509 \
 	$(NULL)
 
 noinst_PROGRAMS += \
diff --git a/common/tests/test-asn1.c b/common/tests/test-asn1.c
new file mode 100644
index 0000000..34e9129
--- /dev/null
+++ b/common/tests/test-asn1.c
@@ -0,0 +1,113 @@
+/*
+ * Copyright (c) 2012 Red Hat Inc.
+ *
+ * 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@gnome.org>
+ */
+
+#include "config.h"
+#include "CuTest.h"
+
+#include "asn1.h"
+#include "debug.h"
+#include "oid.h"
+#include "x509.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+struct {
+	p11_dict *asn1_defs;
+} test;
+
+static void
+setup (CuTest *cu)
+{
+	test.asn1_defs = p11_asn1_defs_load ();
+	CuAssertPtrNotNull (cu, test.asn1_defs);
+}
+
+static void
+teardown (CuTest *cu)
+{
+	p11_dict_free (test.asn1_defs);
+	memset (&test, 0, sizeof (test));
+}
+
+static void
+test_tlv_length (CuTest *cu)
+{
+	struct {
+		const char *der;
+		size_t der_len;
+		int expected;
+	} tlv_lengths[] = {
+		{ "\x01\x01\x00", 3, 3 },
+		{ "\x01\x01\x00\x01\x02", 5, 3 },
+		{ "\x01\x05\x00", 3, -1 },
+		{ NULL }
+	};
+
+	int length;
+	int i;
+
+	setup (cu);
+
+	for (i = 0; tlv_lengths[i].der != NULL; i++) {
+		length = p11_asn1_tlv_length ((const unsigned char *)tlv_lengths[i].der, tlv_lengths[i].der_len);
+		CuAssertIntEquals (cu, tlv_lengths[i].expected, length);
+	}
+
+	teardown (cu);
+}
+
+int
+main (void)
+{
+	CuString *output = CuStringNew ();
+	CuSuite* suite = CuSuiteNew ();
+	int ret;
+
+	setenv ("P11_KIT_STRICT", "1", 1);
+	p11_debug_init ();
+
+	SUITE_ADD_TEST (suite, test_tlv_length);
+
+	CuSuiteRun (suite);
+	CuSuiteSummary (suite, output);
+	CuSuiteDetails (suite, output);
+	printf ("%s\n", output->buffer);
+	ret = suite->failCount;
+	CuSuiteDelete (suite);
+	CuStringDelete (output);
+
+	return ret;
+}
diff --git a/common/tests/test-x509.c b/common/tests/test-x509.c
new file mode 100644
index 0000000..17e25bf
--- /dev/null
+++ b/common/tests/test-x509.c
@@ -0,0 +1,185 @@
+/*
+ * Copyright (c) 2012 Red Hat Inc.
+ *
+ * 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@gnome.org>
+ */
+
+#include "config.h"
+#include "CuTest.h"
+
+#include "asn1.h"
+#include "debug.h"
+#include "oid.h"
+#include "x509.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+struct {
+	p11_dict *asn1_defs;
+} test;
+
+static void
+setup (CuTest *cu)
+{
+	test.asn1_defs = p11_asn1_defs_load ();
+	CuAssertPtrNotNull (cu, test.asn1_defs);
+}
+
+static void
+teardown (CuTest *cu)
+{
+	p11_dict_free (test.asn1_defs);
+	memset (&test, 0, sizeof (test));
+}
+
+static const char test_ku_ds_and_np[] = {
+	0x03, 0x03, 0x07, 0xc0, 0x00,
+};
+
+static const char test_ku_none[] = {
+	0x03, 0x03, 0x07, 0x00, 0x00,
+};
+
+static const char test_ku_cert_crl_sign[] = {
+	0x03, 0x03, 0x07, 0x06, 0x00,
+};
+
+static const char test_eku_server_and_client[] = {
+	0x30, 0x14, 0x06, 0x08, 0x2b, 0x06, 0x01, 0x05, 0x05, 0x07, 0x03, 0x01, 0x06, 0x08, 0x2b, 0x06,
+	0x01, 0x05, 0x05, 0x07, 0x03, 0x02,
+};
+
+static const char test_eku_none[] = {
+	0x30, 0x00,
+};
+
+static const char test_eku_client_email_and_timestamp[] = {
+	0x30, 0x1e, 0x06, 0x08, 0x2b, 0x06, 0x01, 0x05, 0x05, 0x07, 0x03, 0x02, 0x06, 0x08, 0x2b, 0x06,
+	0x01, 0x05, 0x05, 0x07, 0x03, 0x04, 0x06, 0x08, 0x2b, 0x06, 0x01, 0x05, 0x05, 0x07, 0x03, 0x08,
+};
+
+struct {
+	const char *eku;
+	size_t length;
+	const char *expected[16];
+} extended_key_usage_fixtures[] = {
+	{ test_eku_server_and_client, sizeof (test_eku_server_and_client),
+	  { P11_OID_CLIENT_AUTH_STR, P11_OID_SERVER_AUTH_STR, NULL }, },
+	{ test_eku_none, sizeof (test_eku_none),
+	  { NULL, }, },
+	{ test_eku_client_email_and_timestamp, sizeof (test_eku_client_email_and_timestamp),
+	  { P11_OID_CLIENT_AUTH_STR, P11_OID_EMAIL_PROTECTION_STR, P11_OID_TIME_STAMPING_STR }, },
+	{ NULL },
+};
+
+static void
+test_parse_extended_key_usage (CuTest *cu)
+{
+	p11_dict *ekus;
+	int i, j;
+
+	setup (cu);
+
+	for (i = 0; extended_key_usage_fixtures[i].eku != NULL; i++) {
+		ekus = p11_x509_parse_extended_key_usage (test.asn1_defs,
+		                                          (const unsigned char *)extended_key_usage_fixtures[i].eku,
+		                                          extended_key_usage_fixtures[i].length);
+		CuAssertPtrNotNull (cu, ekus);
+
+		for (j = 0; extended_key_usage_fixtures[i].expected[j] != NULL; j++)
+			CuAssertTrue (cu, p11_dict_get (ekus, extended_key_usage_fixtures[i].expected[j]) != NULL);
+		CuAssertIntEquals (cu, j, p11_dict_size (ekus));
+
+		p11_dict_free (ekus);
+	}
+
+	teardown (cu);
+}
+
+struct {
+	const char *ku;
+	size_t length;
+	unsigned int expected;
+} key_usage_fixtures[] = {
+	{ test_ku_ds_and_np, sizeof (test_ku_ds_and_np), P11_KU_DIGITAL_SIGNATURE | P11_KU_NON_REPUDIATION },
+	{ test_ku_none, sizeof (test_ku_none), 0 },
+	{ test_ku_cert_crl_sign, sizeof (test_ku_cert_crl_sign), P11_KU_KEY_CERT_SIGN | P11_KU_CRL_SIGN },
+	{ NULL },
+};
+
+static void
+test_parse_key_usage (CuTest *cu)
+{
+	unsigned int ku;
+	int i;
+	bool ret;
+
+	setup (cu);
+
+	for (i = 0; key_usage_fixtures[i].ku != NULL; i++) {
+		ku = 0;
+
+		ret = p11_x509_parse_key_usage (test.asn1_defs,
+		                                (const unsigned char *)key_usage_fixtures[i].ku,
+		                                key_usage_fixtures[i].length, &ku);
+		CuAssertIntEquals (cu, true, ret);
+
+		CuAssertIntEquals (cu, key_usage_fixtures[i].expected, ku);
+	}
+
+	teardown (cu);
+}
+
+int
+main (void)
+{
+	CuString *output = CuStringNew ();
+	CuSuite* suite = CuSuiteNew ();
+	int ret;
+
+	setenv ("P11_KIT_STRICT", "1", 1);
+	p11_debug_init ();
+
+	SUITE_ADD_TEST (suite, test_parse_extended_key_usage);
+	SUITE_ADD_TEST (suite, test_parse_key_usage);
+
+	CuSuiteRun (suite);
+	CuSuiteSummary (suite, output);
+	CuSuiteDetails (suite, output);
+	printf ("%s\n", output->buffer);
+	ret = suite->failCount;
+	CuSuiteDelete (suite);
+	CuStringDelete (output);
+
+	return ret;
+}
diff --git a/common/x509.c b/common/x509.c
new file mode 100644
index 0000000..8eb513d
--- /dev/null
+++ b/common/x509.c
@@ -0,0 +1,152 @@
+/*
+ * Copyright (C) 2012 Red Hat Inc.
+ *
+ * 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@redhat.com>
+ */
+
+#include "config.h"
+
+#include "asn1.h"
+#define P11_DEBUG_FLAG P11_DEBUG_TRUST
+#include "debug.h"
+#include "oid.h"
+#include "x509.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+bool
+p11_x509_parse_basic_constraints (p11_dict *asn1_defs,
+                                  const unsigned char *ext_der,
+                                  size_t ext_len,
+                                  bool *is_ca)
+{
+	char buffer[8];
+	node_asn *ext;
+	int ret;
+	int len;
+
+	return_val_if_fail (is_ca != NULL, false);
+
+	ext = p11_asn1_decode (asn1_defs, "PKIX1.BasicConstraints", ext_der, ext_len, NULL);
+	if (ext == NULL)
+		return false;
+
+	len = sizeof (buffer);
+	ret = asn1_read_value (ext, "cA", buffer, &len);
+	return_val_if_fail (ret == ASN1_SUCCESS, false);
+
+	*is_ca = (strcmp (buffer, "TRUE") == 0);
+	asn1_delete_structure (&ext);
+
+	return true;
+}
+
+bool
+p11_x509_parse_key_usage (p11_dict *asn1_defs,
+                          const unsigned char *ext_der,
+                          size_t ext_len,
+                          unsigned int *ku)
+{
+	char message[ASN1_MAX_ERROR_DESCRIPTION_SIZE] = { 0, };
+	unsigned char buf[2];
+	node_asn *ext;
+	int len;
+	int ret;
+
+	ext = p11_asn1_decode (asn1_defs, "PKIX1.KeyUsage", ext_der, ext_len, message);
+	if (ext == NULL)
+		return false;
+
+	len = sizeof (buf);
+	ret = asn1_read_value (ext, "", buf, &len);
+	return_val_if_fail (ret == ASN1_SUCCESS, false);
+
+	/* A bit string, so combine into one set of flags */
+	*ku = buf[0] | (buf[1] << 8);
+
+	asn1_delete_structure (&ext);
+
+	return true;
+}
+
+p11_dict *
+p11_x509_parse_extended_key_usage (p11_dict *asn1_defs,
+                                   const unsigned char *ext_der,
+                                   size_t ext_len)
+{
+	node_asn *asn;
+	char field[128];
+	p11_dict *ekus;
+	char *eku;
+	int ret;
+	int len;
+	int i;
+
+	asn = p11_asn1_decode (asn1_defs, "PKIX1.ExtKeyUsageSyntax", ext_der, ext_len, NULL);
+	if (asn == NULL)
+		return NULL;
+
+	ekus = p11_dict_new (p11_dict_str_hash, p11_dict_str_equal, free, NULL);
+
+	for (i = 1; ; i++) {
+		if (snprintf (field, sizeof (field), "?%u", i) < 0)
+			return_val_if_reached (NULL);
+
+		len = 0;
+		ret = asn1_read_value (asn, field, NULL, &len);
+		if (ret == ASN1_ELEMENT_NOT_FOUND)
+			break;
+
+		return_val_if_fail (ret == ASN1_MEM_ERROR, NULL);
+
+		eku = malloc (len + 1);
+		return_val_if_fail (eku != NULL, NULL);
+
+		ret = asn1_read_value (asn, field, eku, &len);
+		return_val_if_fail (ret == ASN1_SUCCESS, NULL);
+
+		eku[len] = 0;
+
+		/* If it's our reserved OID, then skip */
+		if (strcmp (eku, P11_OID_RESERVED_PURPOSE_STR) == 0) {
+			free (eku);
+			continue;
+		}
+
+		if (!p11_dict_set (ekus, eku, eku))
+			return_val_if_reached (NULL);
+	}
+
+	asn1_delete_structure (&asn);
+
+	return ekus;
+}
diff --git a/common/x509.h b/common/x509.h
new file mode 100644
index 0000000..b7c9a5e
--- /dev/null
+++ b/common/x509.h
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2012 Red Hat Inc.
+ *
+ * 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@redhat.com>
+ */
+
+#include <libtasn1.h>
+
+#include "dict.h"
+
+#ifndef P11_X509_H_
+#define P11_X509_H_
+
+bool             p11_x509_parse_basic_constraints   (p11_dict *asn1_defs,
+                                                     const unsigned char *ext_der,
+                                                     size_t ext_len,
+                                                     bool *is_ca);
+
+bool             p11_x509_parse_key_usage           (p11_dict *asn1_defs,
+                                                     const unsigned char *data,
+                                                     size_t length,
+                                                     unsigned int *ku);
+
+p11_dict *       p11_x509_parse_extended_key_usage  (p11_dict *asn1_defs,
+                                                     const unsigned char *ext_der,
+                                                     size_t ext_len);
+
+#endif /* P11_X509_H_ */