common: Move debug and userpref code into libinternalcommon

5 files changed, 1465 insertions, 1 deletions

diff --git a/common/Makefile.am b/common/Makefile.am
index dfa6852..664e13b 100644
--- a/common/Makefile.am
+++ b/common/Makefile.am
@@ -8,7 +8,9 @@ libinternalcommon_la_LIBADD =
 libinternalcommon_la_LDFLAGS = $(AM_LDFLAGS) -no-undefined
 libinternalcommon_la_SOURCES = \
 		       socket.c socket.h \
-		       thread.c thread.h
+		       thread.c thread.h \
+		       debug.c debug.h \
+		       userpref.c userpref.h
 
 if WIN32
 libinternalcommon_la_LIBADD += -lole32
diff --git a/common/debug.c b/common/debug.c
new file mode 100644
index 0000000..0bb87a2
--- /dev/null
+++ b/common/debug.c
@@ -0,0 +1,169 @@
+/*
+ * debug.c
+ * contains utilitary functions for debugging
+ *
+ * Copyright (c) 2008 Jonathan Beck All Rights Reserved.
+ * Copyright (c) 2010 Martin S. All Rights Reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ * 
+ * This library 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
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA 
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+#include <stdarg.h>
+#define _GNU_SOURCE 1
+#define __USE_GNU 1
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <time.h>
+
+#include "debug.h"
+#include "libimobiledevice/libimobiledevice.h"
+
+#ifndef STRIP_DEBUG_CODE
+#include "asprintf.h"
+#endif
+
+int debug_level = 0;
+
+/**
+ * Sets the level of debugging. Currently the only acceptable values are 0 and
+ * 1.
+ *
+ * @param level Set to 0 for no debugging or 1 for debugging.
+ */
+void idevice_set_debug_level(int level)
+{
+	debug_level = level;
+}
+
+#ifndef STRIP_DEBUG_CODE
+static void debug_print_line(const char *func, const char *file, int line, const char *buffer)
+{
+	char *str_time = NULL;
+	char *header = NULL;
+	time_t the_time;
+
+	time(&the_time);
+	str_time = (char*)malloc(255);
+	strftime(str_time, 254, "%H:%M:%S", localtime (&the_time));
+
+	/* generate header text */
+	(void)asprintf(&header, "%s %s:%d %s()", str_time, file, line, func);
+	free (str_time);
+
+	/* trim ending newlines */
+
+	/* print header */
+	printf ("%s: ", header);
+
+	/* print actual debug content */
+	printf ("%s\n", buffer);
+
+	/* flush this output, as we need to debug */
+	fflush (stdout);
+
+	free (header);
+}
+#endif
+
+inline void debug_info_real(const char *func, const char *file, int line, const char *format, ...)
+{
+#ifndef STRIP_DEBUG_CODE
+	va_list args;
+	char *buffer = NULL;
+
+	if (!debug_level)
+		return;
+
+	/* run the real fprintf */
+	va_start(args, format);
+	(void)vasprintf(&buffer, format, args);
+	va_end(args);
+
+	debug_print_line(func, file, line, buffer);
+
+	free(buffer);
+#endif
+}
+
+inline void debug_buffer(const char *data, const int length)
+{
+#ifndef STRIP_DEBUG_CODE
+	int i;
+	int j;
+	unsigned char c;
+
+	if (debug_level) {
+		for (i = 0; i < length; i += 16) {
+			fprintf(stderr, "%04x: ", i);
+			for (j = 0; j < 16; j++) {
+				if (i + j >= length) {
+					fprintf(stderr, "   ");
+					continue;
+				}
+				fprintf(stderr, "%02hhx ", *(data + i + j));
+			}
+			fprintf(stderr, "  | ");
+			for (j = 0; j < 16; j++) {
+				if (i + j >= length)
+					break;
+				c = *(data + i + j);
+				if ((c < 32) || (c > 127)) {
+					fprintf(stderr, ".");
+					continue;
+				}
+				fprintf(stderr, "%c", c);
+			}
+			fprintf(stderr, "\n");
+		}
+		fprintf(stderr, "\n");
+	}
+#endif
+}
+
+inline void debug_buffer_to_file(const char *file, const char *data, const int length)
+{
+#ifndef STRIP_DEBUG_CODE
+	if (debug_level) {
+		FILE *f = fopen(file, "wb");
+		fwrite(data, 1, length, f);
+		fflush(f);
+		fclose(f);
+	}
+#endif
+}
+
+inline void debug_plist_real(const char *func, const char *file, int line, plist_t plist)
+{
+#ifndef STRIP_DEBUG_CODE
+	if (!plist)
+		return;
+
+	char *buffer = NULL;
+	uint32_t length = 0;
+	plist_to_xml(plist, &buffer, &length);
+
+	/* get rid of ending newline as one is already added in the debug line */
+	if (buffer[length-1] == '\n')
+		buffer[length-1] = '\0';
+
+	debug_info_real(func, file, line, "printing %i bytes plist:\n%s", length, buffer);
+	free(buffer);
+#endif
+}
+
diff --git a/common/debug.h b/common/debug.h
new file mode 100644
index 0000000..b7cff80
--- /dev/null
+++ b/common/debug.h
@@ -0,0 +1,59 @@
+/*
+ * debug.h
+ * contains utilitary functions for debugging
+ *
+ * Copyright (c) 2008 Jonathan Beck All Rights Reserved.
+ * Copyright (c) 2010 Martin S. All Rights Reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ * 
+ * This library 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
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA 
+ */
+
+#ifndef __DEBUG_H
+#define __DEBUG_H
+
+#include <plist/plist.h>
+
+#ifndef LIBIMOBILEDEVICE_INTERNAL
+#ifdef WIN32
+#define LIBIMOBILEDEVICE_INTERNAL
+#else
+#define LIBIMOBILEDEVICE_INTERNAL __attribute__((visibility("hidden")))
+#endif
+#endif
+
+#if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L && !defined(STRIP_DEBUG_CODE)
+#define debug_info(...) debug_info_real (__func__, __FILE__, __LINE__, __VA_ARGS__)
+#define debug_plist(a) debug_plist_real (__func__, __FILE__, __LINE__, a)
+#elif defined(__GNUC__) && __GNUC__ >= 3 && !defined(STRIP_DEBUG_CODE)
+#define debug_info(...) debug_info_real (__FUNCTION__, __FILE__, __LINE__, __VA_ARGS__)
+#define debug_plist(a) debug_plist_real (__FUNCTION__, __FILE__, __LINE__, a)
+#else
+#define debug_info(...)
+#define debug_plist(a)
+#endif
+
+LIBIMOBILEDEVICE_INTERNAL inline void debug_info_real(const char *func,
+											const char *file,
+											int	line,
+											const char *format, ...);
+
+LIBIMOBILEDEVICE_INTERNAL inline void debug_buffer(const char *data, const int length);
+LIBIMOBILEDEVICE_INTERNAL inline void debug_buffer_to_file(const char *file, const char *data, const int length);
+LIBIMOBILEDEVICE_INTERNAL inline void debug_plist_real(const char *func,
+											const char *file,
+											int	line,
+											plist_t plist);
+
+#endif
diff --git a/common/userpref.c b/common/userpref.c
new file mode 100644
index 0000000..0e774b7
--- /dev/null
+++ b/common/userpref.c
@@ -0,0 +1,1161 @@
+/*
+ * userpref.c
+ * contains methods to access user specific certificates IDs and more.
+ *
+ * Copyright (c) 2008 Jonathan Beck All Rights Reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#ifdef HAVE_OPENSSL
+#include <openssl/pem.h>
+#include <openssl/rsa.h>
+#include <openssl/x509.h>
+#include <openssl/x509v3.h>
+#else
+#include <gnutls/gnutls.h>
+#include <gnutls/x509.h>
+#include <gcrypt.h>
+#endif
+
+#include <dirent.h>
+#include <libgen.h>
+#include <sys/stat.h>
+#include <errno.h>
+
+#ifdef WIN32
+#include <shlobj.h>
+#endif
+
+#include "userpref.h"
+#include "debug.h"
+
+#define LIBIMOBILEDEVICE_CONF_DIR  "libimobiledevice"
+#define LIBIMOBILEDEVICE_CONF_FILE "libimobiledevicerc"
+
+#define LIBIMOBILEDEVICE_ROOT_PRIVKEY "RootPrivateKey.pem"
+#define LIBIMOBILEDEVICE_HOST_PRIVKEY "HostPrivateKey.pem"
+#define LIBIMOBILEDEVICE_ROOT_CERTIF "RootCertificate.pem"
+#define LIBIMOBILEDEVICE_HOST_CERTIF "HostCertificate.pem"
+
+#ifdef WIN32
+#define DIR_SEP '\\'
+#define DIR_SEP_S "\\"
+#else
+#define DIR_SEP '/'
+#define DIR_SEP_S "/"
+#endif
+
+static char __config_dir[512] = {0, };
+
+#ifdef WIN32
+static char *userpref_utf16_to_utf8(wchar_t *unistr, long len, long *items_read, long *items_written)
+{
+	if (!unistr || (len <= 0)) return NULL;
+	char *outbuf = (char*)malloc(3*(len+1));
+	int p = 0;
+	int i = 0;
+
+	wchar_t wc;
+
+	while (i < len) {
+		wc = unistr[i++];
+		if (wc >= 0x800) {
+			outbuf[p++] = (char)(0xE0 + ((wc >> 12) & 0xF));
+			outbuf[p++] = (char)(0x80 + ((wc >> 6) & 0x3F));
+			outbuf[p++] = (char)(0x80 + (wc & 0x3F));
+		} else if (wc >= 0x80) {
+			outbuf[p++] = (char)(0xC0 + ((wc >> 6) & 0x1F));
+			outbuf[p++] = (char)(0x80 + (wc & 0x3F));
+		} else {
+			outbuf[p++] = (char)(wc & 0x7F);
+		}
+	}
+	if (items_read) {
+		*items_read = i;
+	}
+	if (items_written) {
+		*items_written = p;
+	}
+	outbuf[p] = 0;
+
+	return outbuf;
+}
+#endif
+
+static const char *userpref_get_tmp_dir()
+{
+	const char *cdir = getenv("TMPDIR");
+	if (cdir && cdir[0])
+		return cdir;
+	cdir = getenv("TMP");
+	if (cdir && cdir[0])
+		return cdir;
+	cdir = getenv("TEMP");
+	if (cdir && cdir[0])
+		return cdir;
+	return "/tmp";
+}
+
+static const char *userpref_get_config_dir()
+{
+	if (__config_dir[0]) return __config_dir;
+#ifdef WIN32
+	wchar_t path[MAX_PATH+1];
+	HRESULT hr;
+	LPITEMIDLIST pidl = NULL;
+	BOOL b = FALSE;
+
+	hr = SHGetSpecialFolderLocation (NULL, CSIDL_LOCAL_APPDATA, &pidl);
+	if (hr == S_OK) {
+		b = SHGetPathFromIDListW (pidl, path);
+		if (b) {
+			char *cdir = userpref_utf16_to_utf8 (path, wcslen(path), NULL, NULL);
+			strcpy(__config_dir, cdir);
+			free(cdir);
+			CoTaskMemFree (pidl);
+		}
+	}
+#else
+	const char *cdir = getenv("XDG_CONFIG_HOME");
+	if (!cdir) {
+		cdir = getenv("HOME");
+		if (!cdir || !cdir[0]) {
+			const char *tdir = userpref_get_tmp_dir();
+			strcpy(__config_dir, tdir);
+			strcat(__config_dir, DIR_SEP_S);
+			strcat(__config_dir, "root");
+		} else {
+			strcpy(__config_dir, cdir);
+		}
+		strcat(__config_dir, DIR_SEP_S);
+		strcat(__config_dir, ".config");
+	} else {
+		strcpy(__config_dir, cdir);
+	}
+#endif
+	strcat(__config_dir, DIR_SEP_S);
+	strcat(__config_dir, LIBIMOBILEDEVICE_CONF_DIR);
+
+	int i = strlen(__config_dir)-1;	
+	while ((i > 0) && (__config_dir[i] == DIR_SEP)) {
+		__config_dir[i--] = '\0';
+	}
+
+	return __config_dir;
+}
+
+static int __mkdir(const char *dir, int mode)
+{
+#ifdef WIN32
+	return mkdir(dir);
+#else
+	return mkdir(dir, mode);
+#endif
+}
+
+static int mkdir_with_parents(const char *dir, int mode)
+{
+	if (!dir) return -1;
+	if (__mkdir(dir, mode) == 0) {
+		return 0;
+	} else {
+		if (errno == EEXIST) return 0;	
+	}
+	int res;
+	char *parent = strdup(dir);
+	parent = dirname(parent);
+	if (parent) {
+		res = mkdir_with_parents(parent, mode);
+	} else {
+		res = -1;	
+	}
+	free(parent);
+	if (res == 0) {
+		mkdir_with_parents(dir, mode);
+	}
+	return res;
+}
+
+static int config_write(const char *cfgfile, plist_t dict)
+{
+	if (!cfgfile || !dict || (plist_get_node_type(dict) != PLIST_DICT)) {
+		return -1;
+	}
+	int res = -1;
+
+#if 1 // old style config
+	plist_t hostid = plist_dict_get_item(dict, "HostID");
+	if (hostid && (plist_get_node_type(hostid) == PLIST_STRING)) {
+		char *hostidstr = NULL;
+		plist_get_string_val(hostid, &hostidstr);
+		if (hostidstr) {
+			FILE *fd = fopen(cfgfile, "wb");
+			if (fd) {
+				fprintf(fd, "\n[Global]\nHostID=%s\n", hostidstr);
+				fclose(fd);
+				res = 0;
+			} else {
+				debug_info("could not open '%s' for writing: %s", cfgfile, strerror(errno));
+			}
+			free(hostidstr);
+		}
+	}
+#endif
+#if 0
+	char *xml = NULL;
+	uint32_t length = 0;
+
+	plist_to_xml(dict, &xml, &length);
+	if (!xml) {
+		return res;
+	}
+
+	FILE *fd = fopen(cfgfile, "wb");
+	if (!fd) {
+		free(xml);
+		return res;
+	}
+
+	if (fwrite(xml, 1, length, fd) == length) {
+		res = 0;
+	} else {
+		fprintf(stderr, "%s: ERROR: failed to write configuration to '%s'\n", __func__, cfgfile);
+	}
+	fclose(fd);
+
+	free(xml);
+#endif
+	return res;
+}
+
+static int config_read(const char *cfgfile, plist_t *dict)
+{
+	if (!cfgfile || !dict) {
+		return -1;
+	}
+
+	int res = -1;
+	FILE *fd = fopen(cfgfile, "rb");
+	if (!fd) {
+		debug_info("could not open '%s' for reading: %s", cfgfile, strerror(errno));
+		return -1;
+	}
+
+	fseek(fd, 0, SEEK_END);
+	unsigned long int size = ftell(fd);
+	fseek(fd, 0, SEEK_SET);
+	unsigned char *contents = NULL;
+
+	contents = malloc(size);
+	if (fread(contents, 1, size, fd) != size) {
+		free(contents);
+		fclose(fd);
+		return -1;
+	}
+	plist_t plist = NULL;
+
+	if (!memcmp(contents, "bplist00", 8)) {
+		plist_from_bin((const char*)contents, (uint32_t)size, &plist);
+		fclose(fd);
+	} else {
+		if (memchr(contents, '<', size)) {
+			plist_from_xml((const char*)contents, (uint32_t)size, &plist);
+		}
+		if (plist) {
+			fclose(fd);
+		} else {
+			// try parsing old format config file
+			char line[256];
+			fseek(fd, 0, SEEK_SET);
+			while (fgets(line, 256, fd)) {
+				char *p = &line[0];
+				size_t llen = strlen(p)-1;
+				while ((llen > 0) && ((p[llen] == '\n') || (p[llen] == '\r'))) {
+					p[llen] = '\0';
+					llen--;
+				}
+				if (llen == 0) continue;
+				while ((p[0] == '\n') || (p[0] == '\r')) {
+					p++;
+				}
+				if (!strncmp(p, "HostID=", 7)) {
+					plist = plist_new_dict();
+					plist_dict_insert_item(plist, "HostID", plist_new_string(p+7));
+					break;
+				}
+			}
+			fclose(fd);
+#if 0
+			if (plist) {
+				// write new format config
+				config_write(cfgfile, plist);
+			}
+#endif
+		}
+	}
+	free(contents);
+	if (plist) {
+		*dict = plist;
+		res = 0;
+	}
+	return res;
+}
+
+/**
+ * Creates a freedesktop compatible configuration directory.
+ */
+static void userpref_create_config_dir(void)
+{
+	const char *config_path = userpref_get_config_dir();
+	struct stat st;
+	if (stat(config_path, &st) != 0) {
+		mkdir_with_parents(config_path, 0755);
+	}
+}
+
+static int get_rand(int min, int max)
+{
+	int retval = (rand() % (max - min)) + min;
+	return retval;
+}
+
+/**
+ * Generates a valid HostID (which is actually a UUID).
+ *
+ * @return A null terminated string containing a valid HostID.
+ */
+static char *userpref_generate_host_id()
+{
+	/* HostID's are just UUID's, and UUID's are 36 characters long */
+	char *hostid = (char *) malloc(sizeof(char) * 37);
+	const char *chars = "ABCDEF0123456789";
+	srand(time(NULL));
+	int i = 0;
+
+	for (i = 0; i < 36; i++) {
+		if (i == 8 || i == 13 || i == 18 || i == 23) {
+			hostid[i] = '-';
+			continue;
+		} else {
+			hostid[i] = chars[get_rand(0, 16)];
+		}
+	}
+	/* make it a real string */
+	hostid[36] = '\0';
+	return hostid;
+}
+
+/**
+ * Store HostID in config file.
+ *
+ * @param host_id A null terminated string containing a valid HostID.
+ */
+static int userpref_set_host_id(const char *host_id)
+{
+	const char *config_path;
+	char *config_file;
+
+	if (!host_id)
+		return 0;
+
+	/* Make sure config directory exists */
+	userpref_create_config_dir();
+
+	config_path = userpref_get_config_dir();
+	config_file = (char*)malloc(strlen(config_path)+1+strlen(LIBIMOBILEDEVICE_CONF_FILE)+1);
+	strcpy(config_file, config_path);
+	strcat(config_file, DIR_SEP_S);
+	strcat(config_file, LIBIMOBILEDEVICE_CONF_FILE);
+
+	/* Now parse file to get the HostID */
+	plist_t config = NULL;
+	config_read(config_file, &config);
+	if (!config) {
+		config = plist_new_dict();
+		plist_dict_insert_item(config, "HostID", plist_new_string(host_id));
+	} else {
+		plist_t n = plist_dict_get_item(config, "HostID");
+		if (n) {
+			plist_set_string_val(n, host_id);
+		} else {
+			plist_dict_insert_item(config, "HostID", plist_new_string(host_id));
+		}
+	}
+
+	/* Store in config file */
+	debug_info("setting hostID to %s", host_id);
+
+	config_write(config_file, config);
+	plist_free(config);
+
+	free(config_file);
+	return 1;
+}
+
+/**
+ * Reads the HostID from a previously generated configuration file.
+ *
+ * @note It is the responsibility of the calling function to free the returned host_id
+ *
+ * @return The string containing the HostID or NULL
+ */
+void userpref_get_host_id(char **host_id)
+{
+	const char *config_path;
+	char *config_file;
+
+	config_path = userpref_get_config_dir();
+	config_file = (char*)malloc(strlen(config_path)+1+strlen(LIBIMOBILEDEVICE_CONF_FILE)+1);
+	strcpy(config_file, config_path);
+	strcat(config_file, DIR_SEP_S);
+	strcat(config_file, LIBIMOBILEDEVICE_CONF_FILE);
+
+	/* now parse file to get the HostID */
+	plist_t config = NULL;
+	if (config_read(config_file, &config) == 0) {
+		plist_t n_host_id = plist_dict_get_item(config, "HostID");
+		if (n_host_id && (plist_get_node_type(n_host_id) == PLIST_STRING)) {
+			plist_get_string_val(n_host_id, host_id);
+		}
+	}
+	plist_free(config);
+	free(config_file);
+
+	if (!*host_id) {
+		/* no config, generate host_id */
+		*host_id = userpref_generate_host_id();
+		userpref_set_host_id(*host_id);
+	}
+
+	debug_info("Using %s as HostID", *host_id);
+}
+
+/**
+ * Determines whether this device has been connected to this system before.
+ *
+ * @param udid The device UDID as given by the device.
+ *
+ * @return 1 if the device has been connected previously to this configuration
+ *         or 0 otherwise.
+ */
+int userpref_has_device_public_key(const char *udid)
+{
+	int ret = 0;
+	const char *config_path;
+	char *config_file;
+	struct stat st;
+
+	if (!udid) return 0;
+
+	/* first get config file */
+	config_path = userpref_get_config_dir();
+	config_file = (char*)malloc(strlen(config_path)+1+strlen(udid)+4+1);
+	strcpy(config_file, config_path);
+	strcat(config_file, DIR_SEP_S);
+	strcat(config_file, udid);
+	strcat(config_file, ".pem");
+
+	if ((stat(config_file, &st) == 0) && S_ISREG(st.st_mode))
+		ret = 1;
+	free(config_file);
+	return ret;
+}
+
+/**
+ * Fills a list with UDIDs of devices that have been connected to this
+ * system before, i.e. for which a public key file exists.
+ *
+ * @param list A pointer to a char** initially pointing to NULL that will
+ *        hold a newly allocated list of UDIDs upon successful return.
+ *        The caller is responsible for freeing the memory. Note that if
+ *        no public key file was found the list has to be freed too as it
+ *        points to a terminating NULL element.
+ * @param count The number of UDIDs found. This parameter can be NULL if it
+ *        is not required.
+ *
+ * @return USERPREF_E_SUCCESS on success, or USERPREF_E_INVALID_ARG if the 
+ *         list parameter is not pointing to NULL.
+ */
+userpref_error_t userpref_get_paired_udids(char ***list, unsigned int *count)
+{
+	struct slist_t {
+		char *name;
+		void *next;
+	};
+	DIR *config_dir;
+	const char *config_path;
+	struct slist_t *udids = NULL;
+	unsigned int i;
+	unsigned int found = 0;
+
+	if (!list || (list && *list)) {
+		debug_info("ERROR: The list parameter needs to point to NULL!");
+		return USERPREF_E_INVALID_ARG;
+	}
+
+	if (count) {
+		*count = 0;
+	}
+
+	config_path = userpref_get_config_dir();
+	config_dir = opendir(config_path);
+	if (config_dir) {
+		struct dirent *entry;
+		struct slist_t *listp = udids;
+		while ((entry = readdir(config_dir))) {
+			char *ext = strstr(entry->d_name, ".pem");
+			if (ext && ((ext - entry->d_name) == 40) && (strlen(entry->d_name) == 44)) {
+				struct slist_t *ne = (struct slist_t*)malloc(sizeof(struct slist_t));
+				ne->name = (char*)malloc(41);
+				strncpy(ne->name, entry->d_name, 40);
+				ne->name[40] = 0;
+				ne->next = NULL;
+				if (!listp) {
+					listp = ne;
+					udids = listp;
+				} else {
+					listp->next = ne;
+					listp = listp->next;
+				}
+				found++;
+			}
+		}
+		closedir(config_dir);
+	}
+	*list = (char**)malloc(sizeof(char*) * (found+1));
+	i = 0;
+	while (udids) {
+		(*list)[i++] = udids->name;
+		struct slist_t *old = udids;
+		udids = udids->next;
+		free(old);
+	}
+	(*list)[i] = NULL;
+
+	if (count) {
+		*count = found;
+	}
+
+	return USERPREF_E_SUCCESS;
+}
+
+/**
+ * Mark the device (as represented by the key) as having connected to this
+ * configuration.
+ *
+ * @param udid The device UDID as given by the device
+ * @param public_key The public key given by the device
+ *
+ * @return 1 on success and 0 if no public key is given or if it has already
+ *         been marked as connected previously.
+ */
+userpref_error_t userpref_set_device_public_key(const char *udid, key_data_t public_key)
+{
+	if (NULL == public_key.data)
+		return USERPREF_E_INVALID_ARG;
+	
+	if (userpref_has_device_public_key(udid))
+		return USERPREF_E_SUCCESS;
+
+	/* ensure config directory exists */
+	userpref_create_config_dir();
+
+	/* build file path */
+	const char *config_path = userpref_get_config_dir();
+	char *pem = (char*)malloc(strlen(config_path)+1+strlen(udid)+4+1);
+	strcpy(pem, config_path);
+	strcat(pem, DIR_SEP_S);
+	strcat(pem, udid);
+	strcat(pem, ".pem");
+
+	/* store file */
+	FILE *pFile = fopen(pem, "wb");
+	if (pFile) {
+		fwrite(public_key.data, 1, public_key.size, pFile);
+		fclose(pFile);
+	} else {
+		debug_info("could not open '%s' for writing: %s", pem, strerror(errno));
+	}
+	free(pem);
+
+	return USERPREF_E_SUCCESS;
+}
+
+/**
+ * Remove the public key stored for the device with udid from this host.
+ *
+ * @param udid The udid of the device
+ *
+ * @return USERPREF_E_SUCCESS on success.
+ */
+userpref_error_t userpref_remove_device_public_key(const char *udid)
+{
+	if (!userpref_has_device_public_key(udid))
+		return USERPREF_E_SUCCESS;
+
+	/* build file path */
+	const char *config_path = userpref_get_config_dir();
+	char *pem = (char*)malloc(strlen(config_path)+1+strlen(udid)+4+1);
+	strcpy(pem, config_path);
+	strcat(pem, DIR_SEP_S);
+	strcat(pem, udid);
+	strcat(pem, ".pem");
+
+	/* remove file */
+	remove(pem);
+
+	free(pem);
+
+	return USERPREF_E_SUCCESS;
+}
+
+/**
+ * Private function which reads the given file into a key_data_t structure.
+ *
+ * @param file The filename of the file to read
+ * @param data The pointer at which to store the data.
+ *
+ * @return 1 if the file contents where read successfully and 0 otherwise.
+ */
+static int userpref_get_file_contents(const char *file, key_data_t * data)
+{
+	int success = 0;
+	unsigned long int size = 0;
+	unsigned char *content = NULL;
+	const char *config_path;
+	char *filepath;
+	FILE *fd;
+
+	if (NULL == file || NULL == data)
+		return 0;
+
+	/* Read file */
+	config_path = userpref_get_config_dir();
+	filepath = (char*)malloc(strlen(config_path)+1+strlen(file)+1);
+	strcpy(filepath, config_path);
+	strcat(filepath, DIR_SEP_S);
+	strcat(filepath, file);
+
+	fd = fopen(filepath, "rb");
+	if (fd) {
+		fseek(fd, 0, SEEK_END);
+		size = ftell(fd);
+		fseek(fd, 0, SEEK_SET);
+
+		// prevent huge files
+		if (size > 0xFFFFFF) {
+			fprintf(stderr, "%s: file is too big (> 16MB). Refusing to read the contents to memory!", __func__);
+		} else {
+			size_t p = 0;
+			content = (unsigned char*)malloc(size);
+			while (!feof(fd)) {
+				p += fread(content+p, 1, size-p, fd);
+				if (ferror(fd) != 0) {
+					break;
+				}
+				if (p >= size) {
+					success = 1;
+					break;
+				}
+			}
+		}
+		fclose(fd);
+	}
+
+	free(filepath);
+
+	/* Add it to the key_data_t structure */
+	if (success) {
+		data->data = (uint8_t*) content;
+		data->size = size;
+	}
+
+	return success;
+}
+
+/**
+ * Private function which generate private keys and certificates.
+ *
+ * @return 1 if keys were successfully generated, 0 otherwise
+ */
+static userpref_error_t userpref_gen_keys_and_cert(void)
+{
+	userpref_error_t ret = USERPREF_E_SSL_ERROR;
+
+	key_data_t root_key_pem = { NULL, 0 };
+	key_data_t root_cert_pem = { NULL, 0 };
+	key_data_t host_key_pem = { NULL, 0 };
+	key_data_t host_cert_pem = { NULL, 0 };
+
+	debug_info("Generating keys and certificates");
+#ifdef HAVE_OPENSSL
+	RSA* root_keypair = RSA_generate_key(2048, 65537, NULL, NULL);
+	RSA* host_keypair = RSA_generate_key(2048, 65537, NULL, NULL);
+
+	EVP_PKEY* root_pkey = EVP_PKEY_new();
+	EVP_PKEY_assign_RSA(root_pkey, root_keypair);
+
+	EVP_PKEY* host_pkey = EVP_PKEY_new();
+	EVP_PKEY_assign_RSA(host_pkey, host_keypair);
+
+	/* generate root certificate */
+	X509* root_cert = X509_new();
+	{
+		/* set serial number */
+		ASN1_INTEGER* sn = ASN1_INTEGER_new();
+		ASN1_INTEGER_set(sn, 0);
+		X509_set_serialNumber(root_cert, sn);
+		ASN1_INTEGER_free(sn);
+
+		/* set version */
+		X509_set_version(root_cert, 2);
+
+		/* set x509v3 basic constraints */
+		X509_EXTENSION* ext;
+		if (!(ext = X509V3_EXT_conf_nid(NULL, NULL, NID_basic_constraints, (char*)"critical,CA:TRUE"))) {
+			debug_info("ERROR: X509V3_EXT_conf_nid failed");
+		}
+		X509_add_ext(root_cert, ext, -1);
+
+		/* set key validity */
+		ASN1_TIME* asn1time = ASN1_TIME_new();
+		ASN1_TIME_set(asn1time, time(NULL));
+		X509_set_notBefore(root_cert, asn1time);
+		ASN1_TIME_set(asn1time, time(NULL) + (60 * 60 * 24 * 365 * 10));
+		X509_set_notAfter(root_cert, asn1time);
+		ASN1_TIME_free(asn1time);
+
+		/* use root public key for root cert */
+		X509_set_pubkey(root_cert, root_pkey);
+		/* sign root cert with root private key */
+		X509_sign(root_cert, root_pkey, EVP_sha1());
+	}
+
+	/* create host certificate */
+	X509* host_cert = X509_new();
+	{
+		/* set serial number */
+		ASN1_INTEGER* sn = ASN1_INTEGER_new();
+		ASN1_INTEGER_set(sn, 0);
+		X509_set_serialNumber(host_cert, sn);
+		ASN1_INTEGER_free(sn);
+
+		/* set version */
+		X509_set_version(host_cert, 2);
+
+		/* set x509v3 basic constraints */
+		X509_EXTENSION* ext;
+		if (!(ext = X509V3_EXT_conf_nid(NULL, NULL, NID_basic_constraints, (char*)"critical,CA:FALSE"))) {
+			debug_info("ERROR: X509V3_EXT_conf_nid failed");
+		}
+		X509_add_ext(host_cert, ext, -1);
+
+		/* set x509v3 key usage */
+		if (!(ext = X509V3_EXT_conf_nid(NULL, NULL, NID_key_usage, (char*)"digitalSignature,keyEncipherment"))) {
+			debug_info("ERROR: X509V3_EXT_conf_nid failed");
+		}
+		X509_add_ext(host_cert, ext, -1);
+
+		/* set key validity */
+		ASN1_TIME* asn1time = ASN1_TIME_new();
+		ASN1_TIME_set(asn1time, time(NULL));
+		X509_set_notBefore(host_cert, asn1time);
+		ASN1_TIME_set(asn1time, time(NULL) + (60 * 60 * 24 * 365 * 10));
+		X509_set_notAfter(host_cert, asn1time);
+		ASN1_TIME_free(asn1time);
+
+		/* use host public key for host cert */	
+		X509_set_pubkey(host_cert, host_pkey);
+
+		/* sign host cert with root private key */
+		X509_sign(host_cert, root_pkey, EVP_sha1());
+	}
+
+	if (root_cert && root_pkey && host_cert && host_pkey) {
+		BIO* membp;
+
+		membp = BIO_new(BIO_s_mem());
+		if (PEM_write_bio_X509(membp, root_cert) > 0) {
+			root_cert_pem.size = BIO_get_mem_data(membp, &root_cert_pem.data);
+		}
+		membp = BIO_new(BIO_s_mem());
+		if (PEM_write_bio_PrivateKey(membp, root_pkey, NULL, NULL, 0, 0, NULL) > 0) {
+			root_key_pem.size = BIO_get_mem_data(membp, &root_key_pem.data);
+		}
+		membp = BIO_new(BIO_s_mem());
+		if (PEM_write_bio_X509(membp, host_cert) > 0) {
+			host_cert_pem.size = BIO_get_mem_data(membp, &host_cert_pem.data);
+		}
+		membp = BIO_new(BIO_s_mem());
+		if (PEM_write_bio_PrivateKey(membp, host_pkey, NULL, NULL, 0, 0, NULL) > 0) {
+			host_key_pem.size = BIO_get_mem_data(membp, &host_key_pem.data);
+		}
+	}
+
+	EVP_PKEY_free(root_pkey);
+	EVP_PKEY_free(host_pkey);
+
+	X509_free(host_cert);
+	X509_free(root_cert);
+#else
+	gnutls_x509_privkey_t root_privkey;
+	gnutls_x509_crt_t root_cert;
+	gnutls_x509_privkey_t host_privkey;
+	gnutls_x509_crt_t host_cert;
+
+	gnutls_global_deinit();
+	gnutls_global_init();
+
+	//use less secure random to speed up key generation
+	gcry_control(GCRYCTL_ENABLE_QUICK_RANDOM);
+
+	gnutls_x509_privkey_init(&root_privkey);
+	gnutls_x509_privkey_init(&host_privkey);
+
+	gnutls_x509_crt_init(&root_cert);
+	gnutls_x509_crt_init(&host_cert);
+
+	/* generate root key */
+	gnutls_x509_privkey_generate(root_privkey, GNUTLS_PK_RSA, 2048, 0);
+	gnutls_x509_privkey_generate(host_privkey, GNUTLS_PK_RSA, 2048, 0);
+
+	/* generate certificates */
+	gnutls_x509_crt_set_key(root_cert, root_privkey);
+	gnutls_x509_crt_set_serial(root_cert, "\x00", 1);
+	gnutls_x509_crt_set_version(root_cert, 3);
+	gnutls_x509_crt_set_ca_status(root_cert, 1);
+	gnutls_x509_crt_set_activation_time(root_cert, time(NULL));
+	gnutls_x509_crt_set_expiration_time(root_cert, time(NULL) + (60 * 60 * 24 * 365 * 10));
+	gnutls_x509_crt_sign(root_cert, root_cert, root_privkey);
+
+	gnutls_x509_crt_set_key(host_cert, host_privkey);
+	gnutls_x509_crt_set_serial(host_cert, "\x00", 1);
+	gnutls_x509_crt_set_version(host_cert, 3);
+	gnutls_x509_crt_set_ca_status(host_cert, 0);
+	gnutls_x509_crt_set_key_usage(host_cert, GNUTLS_KEY_KEY_ENCIPHERMENT | GNUTLS_KEY_DIGITAL_SIGNATURE);
+	gnutls_x509_crt_set_activation_time(host_cert, time(NULL));
+	gnutls_x509_crt_set_expiration_time(host_cert, time(NULL) + (60 * 60 * 24 * 365 * 10));
+	gnutls_x509_crt_sign(host_cert, root_cert, root_privkey);
+
+	/* export to PEM format */
+	size_t root_key_export_size = 0;
+	size_t host_key_export_size = 0;
+
+	gnutls_x509_privkey_export(root_privkey, GNUTLS_X509_FMT_PEM, NULL, &root_key_export_size);
+	gnutls_x509_privkey_export(host_privkey, GNUTLS_X509_FMT_PEM, NULL, &host_key_export_size);
+
+	root_key_pem.data = gnutls_malloc(root_key_export_size);
+	host_key_pem.data = gnutls_malloc(host_key_export_size);
+
+	gnutls_x509_privkey_export(root_privkey, GNUTLS_X509_FMT_PEM, root_key_pem.data, &root_key_export_size);
+	root_key_pem.size = root_key_export_size;
+	gnutls_x509_privkey_export(host_privkey, GNUTLS_X509_FMT_PEM, host_key_pem.data, &host_key_export_size);
+	host_key_pem.size = host_key_export_size;
+
+	size_t root_cert_export_size = 0;
+	size_t host_cert_export_size = 0;
+
+	gnutls_x509_crt_export(root_cert, GNUTLS_X509_FMT_PEM, NULL, &root_cert_export_size);
+	gnutls_x509_crt_export(host_cert, GNUTLS_X509_FMT_PEM, NULL, &host_cert_export_size);
+
+	root_cert_pem.data = gnutls_malloc(root_cert_export_size);
+	host_cert_pem.data = gnutls_malloc(host_cert_export_size);
+
+	gnutls_x509_crt_export(root_cert, GNUTLS_X509_FMT_PEM, root_cert_pem.data, &root_cert_export_size);
+	root_cert_pem.size = root_cert_export_size;
+	gnutls_x509_crt_export(host_cert, GNUTLS_X509_FMT_PEM, host_cert_pem.data, &host_cert_export_size);
+	host_cert_pem.size = host_cert_export_size;
+
+	//restore gnutls env
+	gnutls_global_deinit();
+	gnutls_global_init();
+#endif
+	if (NULL != root_cert_pem.data && 0 != root_cert_pem.size &&
+		NULL != host_cert_pem.data && 0 != host_cert_pem.size)
+		ret = USERPREF_E_SUCCESS;
+
+	/* store values in config file */
+	userpref_set_keys_and_certs( &root_key_pem, &root_cert_pem, &host_key_pem, &host_cert_pem);
+
+	if (root_key_pem.data)
+		free(root_key_pem.data);
+	if (root_cert_pem.data)
+		free(root_cert_pem.data);
+	if (host_key_pem.data)
+		free(host_key_pem.data);
+	if (host_cert_pem.data)
+		free(host_cert_pem.data);
+
+	return ret;
+}
+
+/**
+ * Private function which import the given key into a gnutls structure.
+ *
+ * @param key_name The filename of the private key to import.
+ * @param key the gnutls key structure.
+ *
+ * @return 1 if the key was successfully imported.
+ */
+#ifdef HAVE_OPENSSL
+static userpref_error_t userpref_import_key(const char* key_name, key_data_t* key)
+#else
+static userpref_error_t userpref_import_key(const char* key_name, gnutls_x509_privkey_t key)
+#endif
+{
+#ifdef HAVE_OPENSSL
+	if (!key)
+		return USERPREF_E_SUCCESS;
+#endif
+	userpref_error_t ret = USERPREF_E_INVALID_CONF;
+	key_data_t pem_key = { NULL, 0 };
+	if (userpref_get_file_contents(key_name, &pem_key)) {
+#ifdef HAVE_OPENSSL
+		key->data = (unsigned char*)malloc(pem_key.size);
+		memcpy(key->data, pem_key.data, pem_key.size);
+		key->size = pem_key.size;
+		ret = USERPREF_E_SUCCESS;
+#else
+		if (GNUTLS_E_SUCCESS == gnutls_x509_privkey_import(key, &pem_key, GNUTLS_X509_FMT_PEM))
+			ret = USERPREF_E_SUCCESS;
+		else
+			ret = USERPREF_E_SSL_ERROR;
+#endif
+	}
+	if (pem_key.data)
+		free(pem_key.data);
+	return ret;
+}
+
+/**
+ * Private function which import the given certificate into a gnutls structure.
+ *
+ * @param crt_name The filename of the certificate to import.
+ * @param cert the gnutls certificate structure.
+ *
+ * @return IDEVICE_E_SUCCESS if the certificate was successfully imported.
+ */
+#ifdef HAVE_OPENSSL
+static userpref_error_t userpref_import_crt(const char* crt_name, key_data_t* cert)
+#else
+static userpref_error_t userpref_import_crt(const char* crt_name, gnutls_x509_crt_t cert)
+#endif
+{
+#ifdef HAVE_OPENSSL
+	if (!cert)
+		return USERPREF_E_SUCCESS;
+#endif
+	userpref_error_t ret = USERPREF_E_INVALID_CONF;
+	key_data_t pem_cert = { NULL, 0 };
+
+	if (userpref_get_file_contents(crt_name, &pem_cert)) {
+#ifdef HAVE_OPENSSL
+		cert->data = (unsigned char*)malloc(pem_cert.size);
+		memcpy(cert->data, pem_cert.data, pem_cert.size);
+		cert->size = pem_cert.size;
+		ret = USERPREF_E_SUCCESS;
+#else
+		if (GNUTLS_E_SUCCESS == gnutls_x509_crt_import(cert, &pem_cert, GNUTLS_X509_FMT_PEM))
+			ret = USERPREF_E_SUCCESS;
+		else
+			ret = USERPREF_E_SSL_ERROR;
+#endif
+	}
+	if (pem_cert.data)
+		free(pem_cert.data);
+	return ret;
+}
+
+/**
+ * Function to retrieve host keys and certificates.
+ * This function trigger key generation if they do not exists yet or are invalid.
+ *
+ * @note This function can take few seconds to complete (typically 5 seconds)
+ *
+ * @param root_privkey The root private key.
+ * @param root_crt The root certificate.
+ * @param host_privkey The host private key.
+ * @param host_crt The host certificate.
+ *
+ * @return 1 if the keys and certificates were successfully retrieved, 0 otherwise
+ */
+#ifdef HAVE_OPENSSL
+userpref_error_t userpref_get_keys_and_certs(key_data_t* root_privkey, key_data_t* root_crt, key_data_t* host_privkey, key_data_t* host_crt)
+#else
+userpref_error_t userpref_get_keys_and_certs(gnutls_x509_privkey_t root_privkey, gnutls_x509_crt_t root_crt, gnutls_x509_privkey_t host_privkey, gnutls_x509_crt_t host_crt)
+#endif
+{
+	userpref_error_t ret = USERPREF_E_SUCCESS;
+
+	if (ret == USERPREF_E_SUCCESS)
+		ret = userpref_import_key(LIBIMOBILEDEVICE_ROOT_PRIVKEY, root_privkey);
+
+	if (ret == USERPREF_E_SUCCESS)
+		ret = userpref_import_key(LIBIMOBILEDEVICE_HOST_PRIVKEY, host_privkey);
+
+	if (ret == USERPREF_E_SUCCESS)
+		ret = userpref_import_crt(LIBIMOBILEDEVICE_ROOT_CERTIF, root_crt);
+
+	if (ret == USERPREF_E_SUCCESS)
+		ret = userpref_import_crt(LIBIMOBILEDEVICE_HOST_CERTIF, host_crt);
+
+	if (USERPREF_E_SUCCESS != ret) {
+		//we had problem reading or importing root cert
+		//try with a new ones.
+		ret = userpref_gen_keys_and_cert();
+
+		if (ret == USERPREF_E_SUCCESS)
+			ret = userpref_import_key(LIBIMOBILEDEVICE_ROOT_PRIVKEY, root_privkey);
+
+		if (ret == USERPREF_E_SUCCESS)
+			ret = userpref_import_key(LIBIMOBILEDEVICE_HOST_PRIVKEY, host_privkey);
+
+		if (ret == USERPREF_E_SUCCESS)
+			ret = userpref_import_crt(LIBIMOBILEDEVICE_ROOT_CERTIF, root_crt);
+
+		if (ret == USERPREF_E_SUCCESS)
+			ret = userpref_import_crt(LIBIMOBILEDEVICE_HOST_CERTIF, host_crt);
+	}
+
+	return ret;
+}
+
+/**
+ * Function to retrieve certificates encoded in PEM format.
+ *
+ * @param pem_root_cert The root certificate.
+ * @param pem_host_cert The host certificate.
+ *
+ * @return 1 if the certificates were successfully retrieved, 0 otherwise
+ */
+userpref_error_t userpref_get_certs_as_pem(key_data_t *pem_root_cert, key_data_t *pem_host_cert)
+{
+	if (!pem_root_cert || !pem_host_cert)
+		return USERPREF_E_INVALID_ARG;
+
+	if (userpref_get_file_contents(LIBIMOBILEDEVICE_ROOT_CERTIF, pem_root_cert) && userpref_get_file_contents(LIBIMOBILEDEVICE_HOST_CERTIF, pem_host_cert))
+		return USERPREF_E_SUCCESS;
+	else {
+		if (pem_root_cert->data) {
+			free(pem_root_cert->data);
+			pem_root_cert->size = 0;
+		}
+		if (pem_host_cert->data) {
+			free(pem_host_cert->data);
+			pem_host_cert->size = 0;
+		}
+	}
+	debug_info("configuration invalid");
+	return USERPREF_E_INVALID_CONF;
+}
+
+/**
+ * Create and save a configuration file containing the given data.
+ *
+ * @note: All fields must specified and be non-null
+ *
+ * @param root_key The root key
+ * @param root_cert The root certificate
+ * @param host_key The host key
+ * @param host_cert The host certificate
+ *
+ * @return 1 on success and 0 otherwise.
+ */
+userpref_error_t userpref_set_keys_and_certs(key_data_t * root_key, key_data_t * root_cert, key_data_t * host_key, key_data_t * host_cert)
+{
+	FILE *pFile;
+	char *pem;
+	const char *config_path;
+	userpref_error_t ret = USERPREF_E_SUCCESS;
+
+	debug_info("saving keys and certs");
+
+	if (!root_key || !host_key || !root_cert || !host_cert) {
+		debug_info("missing key or cert (root_key=%p, host_key=%p, root=cert=%p, host_cert=%p", root_key, host_key, root_cert, host_cert);
+		return USERPREF_E_INVALID_ARG;
+	}
+
+	/* Make sure config directory exists */
+	userpref_create_config_dir();
+
+	config_path = userpref_get_config_dir();
+
+	/* Now write keys and certificates to disk */
+	pem = (char*)malloc(strlen(config_path)+1+strlen(LIBIMOBILEDEVICE_ROOT_PRIVKEY)+1);
+	strcpy(pem, config_path);
+	strcat(pem, DIR_SEP_S);
+	strcat(pem, LIBIMOBILEDEVICE_ROOT_PRIVKEY);
+	pFile = fopen(pem, "wb");
+	if (pFile) {
+		fwrite(root_key->data, 1, root_key->size, pFile);
+		fclose(pFile);
+	} else {
+		debug_info("could not open '%s' for writing: %s", pem, strerror(errno));
+		ret = USERPREF_E_WRITE_ERROR;
+	}
+	free(pem);
+
+	pem = (char*)malloc(strlen(config_path)+1+strlen(LIBIMOBILEDEVICE_HOST_PRIVKEY)+1);
+	strcpy(pem, config_path);
+	strcat(pem, DIR_SEP_S);
+	strcat(pem, LIBIMOBILEDEVICE_HOST_PRIVKEY);
+	pFile = fopen(pem, "wb");
+	if (pFile) {
+		fwrite(host_key->data, 1, host_key->size, pFile);
+		fclose(pFile);
+	} else {
+		debug_info("could not open '%s' for writing: %s", pem, strerror(errno));
+		ret = USERPREF_E_WRITE_ERROR;
+	}
+	free(pem);
+
+	pem = (char*)malloc(strlen(config_path)+1+strlen(LIBIMOBILEDEVICE_ROOT_CERTIF)+1);
+	strcpy(pem, config_path);
+	strcat(pem, DIR_SEP_S);
+	strcat(pem, LIBIMOBILEDEVICE_ROOT_CERTIF);
+	pFile = fopen(pem, "wb");
+	if (pFile) {
+		fwrite(root_cert->data, 1, root_cert->size, pFile);
+		fclose(pFile);
+	} else {
+		debug_info("could not open '%s' for writing: %s", pem, strerror(errno));
+		ret = USERPREF_E_WRITE_ERROR;
+	}
+	free(pem);
+
+	pem = (char*)malloc(strlen(config_path)+1+strlen(LIBIMOBILEDEVICE_HOST_CERTIF)+1);
+	strcpy(pem, config_path);
+	strcat(pem, DIR_SEP_S);
+	strcat(pem, LIBIMOBILEDEVICE_HOST_CERTIF);
+	pFile = fopen(pem, "wb");
+	if (pFile) {
+		fwrite(host_cert->data, 1, host_cert->size, pFile);
+		fclose(pFile);
+	} else {
+		debug_info("could not open '%s' for writing: %s", pem, strerror(errno));
+		ret = USERPREF_E_WRITE_ERROR;
+	}
+	free(pem);
+
+	return ret;
+}
diff --git a/common/userpref.h b/common/userpref.h
new file mode 100644
index 0000000..14db985
--- /dev/null
+++ b/common/userpref.h
@@ -0,0 +1,73 @@
+/*
+ * userpref.h
+ * contains methods to access user specific certificates IDs and more.
+ *
+ * Copyright (c) 2008 Jonathan Beck All Rights Reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#ifndef __USERPREF_H
+#define __USERPREF_H
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#ifdef HAVE_OPENSSL
+typedef struct {
+	unsigned char *data;
+	unsigned int size;
+} key_data_t;
+#else
+#include <gnutls/gnutls.h>
+typedef gnutls_datum_t key_data_t;
+#endif
+
+#include <stdint.h>
+
+#ifndef LIBIMOBILEDEVICE_INTERNAL
+#ifdef WIN32
+#define LIBIMOBILEDEVICE_INTERNAL
+#else
+#define LIBIMOBILEDEVICE_INTERNAL __attribute__((visibility("hidden")))
+#endif
+#endif
+
+#define USERPREF_E_SUCCESS             0
+#define USERPREF_E_INVALID_ARG        -1
+#define USERPREF_E_INVALID_CONF       -2
+#define USERPREF_E_SSL_ERROR          -3
+#define USERPREF_E_READ_ERROR         -4
+#define USERPREF_E_WRITE_ERROR        -5
+
+#define USERPREF_E_UNKNOWN_ERROR    -256
+
+typedef int16_t userpref_error_t;
+
+#ifdef HAVE_OPENSSL
+LIBIMOBILEDEVICE_INTERNAL userpref_error_t userpref_get_keys_and_certs(key_data_t* root_privkey, key_data_t* root_crt, key_data_t* host_privkey, key_data_t* host_crt);
+#else
+LIBIMOBILEDEVICE_INTERNAL userpref_error_t userpref_get_keys_and_certs(gnutls_x509_privkey_t root_privkey, gnutls_x509_crt_t root_crt, gnutls_x509_privkey_t host_privkey, gnutls_x509_crt_t host_crt);
+#endif
+LIBIMOBILEDEVICE_INTERNAL userpref_error_t userpref_set_keys_and_certs(key_data_t * root_key, key_data_t * root_cert, key_data_t * host_key, key_data_t * host_cert);
+LIBIMOBILEDEVICE_INTERNAL userpref_error_t userpref_get_certs_as_pem(key_data_t *pem_root_cert, key_data_t *pem_host_cert);
+LIBIMOBILEDEVICE_INTERNAL userpref_error_t userpref_set_device_public_key(const char *udid, key_data_t public_key);
+userpref_error_t userpref_remove_device_public_key(const char *udid);
+LIBIMOBILEDEVICE_INTERNAL int userpref_has_device_public_key(const char *udid);
+userpref_error_t userpref_get_paired_udids(char ***list, unsigned int *count);
+void userpref_get_host_id(char **host_id);
+
+#endif