Refactor pair record handling to use new usbmuxd pair record interface

This refactoring is mandatory as libimobiledevice should not interact with
the pair record configuration directory which is owned by the usbmuxd user.

This change also adds compatibility for the native usbmuxd and thus pair
records saved by iTunes.

4 files changed, 469 insertions, 585 deletions

diff --git a/common/userpref.c b/common/userpref.c
index c192c1d..d9641cb 100644
--- a/common/userpref.c
+++ b/common/userpref.c
@@ -35,6 +35,7 @@
 #include <pwd.h>
 #endif
 #include <unistd.h>
+#include <usbmuxd.h>
 #ifdef HAVE_OPENSSL
 #include <openssl/pem.h>
 #include <openssl/rsa.h>
@@ -59,6 +60,17 @@
 #include "debug.h"
 #include "utils.h"
 
+#ifndef HAVE_OPENSSL
+const ASN1_ARRAY_TYPE pkcs1_asn1_tab[] = {
+	{"PKCS1", 536872976, 0},
+	{0, 1073741836, 0},
+	{"RSAPublicKey", 536870917, 0},
+	{"modulus", 1073741827, 0},
+	{"publicExponent", 3, 0},
+	{0, 0, 0}
+};
+#endif
+
 #ifdef WIN32
 #define DIR_SEP '\\'
 #define DIR_SEP_S "\\"
@@ -158,274 +170,20 @@ const char *userpref_get_config_dir()
 	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);
-	char* parentdir = dirname(parent);
-	if (parentdir) {
-		res = mkdir_with_parents(parentdir, mode);
-	} else {
-		res = -1;
-	}
-	free(parent);
-	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(int idx)
-{
-	/* 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) - idx);
-	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;
-}
-
-/**
- * Generates a valid BUID for this system (which is actually a UUID).
- *
- * @return A null terminated string containing a valid BUID.
- */
-static char *userpref_generate_system_buid()
-{
-	return userpref_generate_host_id(1);
-}
-
-static int internal_set_value(const char *config_file, const char *key, plist_t value)
-{
-	if (!config_file)
-		return 0;
-
-	/* read file into plist */
-	plist_t config = NULL;
-
-	plist_read_from_filename(&config, config_file);
-	if (!config) {
-		config = plist_new_dict();
-		plist_dict_set_item(config, key, value);
-	} else {
-		plist_t n = plist_dict_get_item(config, key);
-		if (n) {
-			plist_dict_remove_item(config, key);
-		}
-		plist_dict_set_item(config, key, value);
-		remove(config_file);
-	}
-
-	/* store in config file */
-	char *value_string = NULL;
-	if (plist_get_node_type(value) == PLIST_STRING) {
-		plist_get_string_val(value, &value_string);
-		debug_info("setting key %s to %s in config_file %s", key, value_string, config_file);
-		if (value_string)
-			free(value_string);
-	} else {
-		debug_info("setting key %s in config_file %s", key, config_file);
-	}
-
-	plist_write_to_filename(config, config_file, PLIST_FORMAT_XML);
-
-	plist_free(config);
-
-	return 1;
-}
-
-int userpref_set_value(const char *key, plist_t value)
-{
-	const char *config_path = NULL;
-	char *config_file = NULL;
-
-	/* Make sure config directory exists */
-	userpref_create_config_dir();
-
-	config_path = userpref_get_config_dir();
-	config_file = string_concat(config_path, DIR_SEP_S, USERPREF_CONFIG_FILE, NULL);
-
-	int result = internal_set_value(config_file, key, value);
-
-	free(config_file);
-
-	return result;
-}
-
-int userpref_device_record_set_value(const char *udid, const char *key, plist_t value)
-{
-	const char *config_path = NULL;
-	char *config_file = NULL;
-
-	/* Make sure config directory exists */
-	userpref_create_config_dir();
-
-	config_path = userpref_get_config_dir();
-	config_file = string_concat(config_path, DIR_SEP_S, udid, USERPREF_CONFIG_EXTENSION, NULL);
-
-	int result = internal_set_value(config_file, key, value);
-
-	free(config_file);
-
-	return result;
-}
-
-static int internal_get_value(const char* config_file, const char *key, plist_t *value)
-{
-	*value = NULL;
-
-	/* now parse file to get the SystemBUID */
-	plist_t config = NULL;
-	if (plist_read_from_filename(&config, config_file)) {
-		debug_info("reading key %s from config_file %s", key, config_file);
-		plist_t n = plist_dict_get_item(config, key);
-		if (n) {
-			*value = plist_copy(n);
-			n = NULL;
-		}
-	}
-	plist_free(config);
-
-	return 1;
-}
-
-int userpref_get_value(const char *key, plist_t *value)
-{
-	const char *config_path = NULL;
-	char *config_file = NULL;
-
-	config_path = userpref_get_config_dir();
-	config_file = string_concat(config_path, DIR_SEP_S, USERPREF_CONFIG_FILE, NULL);
-
-	int result = internal_get_value(config_file, key, value);
-
-	free(config_file);
-
-	return result;
-}
-
-int userpref_device_record_get_value(const char *udid, const char *key, plist_t *value)
-{
-	const char *config_path = NULL;
-	char *config_file = NULL;
-
-	config_path = userpref_get_config_dir();
-	config_file = string_concat(config_path, DIR_SEP_S, udid, USERPREF_CONFIG_EXTENSION, NULL);
-
-	int result = internal_get_value(config_file, key, value);
-
-	free(config_file);
-
-	return result;
-}
-
-/**
- * Store SystemBUID in config file.
- *
- * @param host_id A null terminated string containing a valid SystemBUID.
- */
-static int userpref_set_system_buid(const char *system_buid)
-{
-	return userpref_set_value(USERPREF_SYSTEM_BUID_KEY, plist_new_string(system_buid));
-}
-
 /**
  * Reads the BUID from a previously generated configuration file.
  *
  * @note It is the responsibility of the calling function to free the returned system_buid
- *
- * @return The string containing the BUID or NULL
+ * @param system_buid A null terminated string containing a valid SystemBUID.
+ * @return 1 if the system buid could be retrieved or 0 otherwise.
  */
-void userpref_get_system_buid(char **system_buid)
+int userpref_read_system_buid(char **system_buid)
 {
-	plist_t value = NULL;
-
-	userpref_get_value(USERPREF_SYSTEM_BUID_KEY, &value);
-
-	if (value && (plist_get_node_type(value) == PLIST_STRING)) {
-		plist_get_string_val(value, system_buid);
-		debug_info("got %s %s", USERPREF_SYSTEM_BUID_KEY, *system_buid);
-	}
-
-	if (value)
-		plist_free(value);
-
-	if (!*system_buid) {
-		/* no config, generate system_buid */
-		debug_info("no previous %s found", USERPREF_SYSTEM_BUID_KEY);
-		*system_buid = userpref_generate_system_buid();
-		userpref_set_system_buid(*system_buid);
-	}
+	int res = usbmuxd_read_buid(system_buid);
 
 	debug_info("using %s as %s", *system_buid, USERPREF_SYSTEM_BUID_KEY);
-}
-
-void userpref_device_record_get_host_id(const char *udid, char **host_id)
-{
-	plist_t value = NULL;
-
-	userpref_device_record_get_value(udid, USERPREF_HOST_ID_KEY, &value);
-
-	if (value && (plist_get_node_type(value) == PLIST_STRING)) {
-		plist_get_string_val(value, host_id);
-	}
-
-	if (value)
-		plist_free(value);
 
-	if (!*host_id) {
-		/* no config, generate host_id */
-		*host_id = userpref_generate_host_id(0);
-		userpref_device_record_set_value(udid, USERPREF_HOST_ID_KEY, plist_new_string(*host_id));
-	}
-
-	debug_info("using %s as %s", *host_id, USERPREF_HOST_ID_KEY);
+	return res;
 }
 
 /**
@@ -436,7 +194,7 @@ void userpref_device_record_get_host_id(const char *udid, char **host_id)
  * @return 1 if the device has been connected previously to this configuration
  *         or 0 otherwise.
  */
-int userpref_has_device_record(const char *udid)
+int userpref_has_pair_record(const char *udid)
 {
 	int ret = 0;
 	const char *config_path = NULL;
@@ -536,50 +294,61 @@ userpref_error_t userpref_get_paired_udids(char ***list, unsigned int *count)
 }
 
 /**
- * Mark the device as having connected to this configuration.
+ * Save a pair record for a device.
  *
  * @param udid The device UDID as given by the device
- * @param device_record The device record with full configuration
+ * @param pair_record The pair record to save
  *
  * @return 1 on success and 0 if no device record is given or if it has already
- *         been marked as connected previously.
+ *         been saved previously.
  */
-userpref_error_t userpref_set_device_record(const char *udid, plist_t device_record)
+userpref_error_t userpref_save_pair_record(const char *udid, plist_t pair_record)
 {
-	/* ensure config directory exists */
-	userpref_create_config_dir();
+	char* record_data = NULL;
+	uint32_t record_size = 0;
 
-	/* build file path */
-	const char *config_path = userpref_get_config_dir();
-	char *device_record_file = string_concat(config_path, DIR_SEP_S, udid, USERPREF_CONFIG_EXTENSION, NULL);
+	plist_to_bin(pair_record, &record_data, &record_size);
 
-	remove(device_record_file);
+	int res = usbmuxd_save_pair_record(udid, record_data, record_size);
 
-	/* store file */
-	if (!plist_write_to_filename(device_record, device_record_file, PLIST_FORMAT_XML)) {
-		debug_info("could not open '%s' for writing: %s", device_record_file, strerror(errno));
-	}
-	free(device_record_file);
+	free(record_data);
 
-	return USERPREF_E_SUCCESS;
+	return res == 0 ? USERPREF_E_SUCCESS: USERPREF_E_UNKNOWN_ERROR;
 }
 
-userpref_error_t userpref_get_device_record(const char *udid, plist_t *device_record)
+/**
+ * Read a pair record for a device.
+ *
+ * @param udid The device UDID as given by the device
+ * @param pair_record The pair record to read
+ *
+ * @return 1 on success and 0 if no device record is given or if it has already
+ *         been saved previously.
+ */
+userpref_error_t userpref_read_pair_record(const char *udid, plist_t *pair_record)
 {
-	/* ensure config directory exists */
-	userpref_create_config_dir();
+	char* record_data = NULL;
+	uint32_t record_size = 0;
+
+	int res = usbmuxd_read_pair_record(udid, &record_data, &record_size);
 
-	/* build file path */
-	const char *config_path = userpref_get_config_dir();
-	char *device_record_file = string_concat(config_path, DIR_SEP_S, udid, USERPREF_CONFIG_EXTENSION, NULL);
+	if (res < 0) {
+		if (record_data)
+			free(record_data);
 
-	/* read file */
-	if (!plist_read_from_filename(device_record, device_record_file)) {
-		debug_info("could not open '%s' for reading: %s", device_record_file, strerror(errno));
+		return USERPREF_E_INVALID_CONF;
 	}
-	free(device_record_file);
 
-	return USERPREF_E_SUCCESS;
+	*pair_record = NULL;
+	if (memcmp(record_data, "bplist00", 8) == 0) {
+		plist_from_bin(record_data, record_size, pair_record);
+	} else {
+		plist_from_xml(record_data, record_size, pair_record);
+	}
+
+	free(record_data);
+
+	return res == 0 ? USERPREF_E_SUCCESS: USERPREF_E_UNKNOWN_ERROR;
 }
 
 /**
@@ -589,87 +358,33 @@ userpref_error_t userpref_get_device_record(const char *udid, plist_t *device_re
  *
  * @return USERPREF_E_SUCCESS on success.
  */
-userpref_error_t userpref_remove_device_record(const char *udid)
+userpref_error_t userpref_delete_pair_record(const char *udid)
 {
-	userpref_error_t res = USERPREF_E_SUCCESS;
-	if (!userpref_has_device_record(udid))
-		return res;
-
-	/* build file path */
-	const char *config_path = userpref_get_config_dir();
-	char *device_record_file = string_concat(config_path, DIR_SEP_S, udid, USERPREF_CONFIG_EXTENSION, NULL);
-
-	/* remove file */
-	if (remove(device_record_file) != 0) {
-		debug_info("could not remove %s: %s", device_record_file, strerror(errno));
-		res = USERPREF_E_UNKNOWN_ERROR;
-	}
+	int res = usbmuxd_delete_pair_record(udid);
 
-	free(device_record_file);
-
-	return res;
+	return res == 0 ? USERPREF_E_SUCCESS: USERPREF_E_UNKNOWN_ERROR;
 }
 
-#if 0
-/**
- * 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)
+#ifdef HAVE_OPENSSL
+static int X509_add_ext_helper(X509 *cert, int nid, char *value)
 {
-	int success = 0;
-	unsigned long int size = 0;
-	unsigned char *content = NULL;
-	const char *config_path = NULL;
-	char *filepath;
-	FILE *fd;
-
-	if (NULL == file || NULL == data)
-		return 0;
-
-	/* Read file */
-	config_path = userpref_get_config_dir();
-	filepath = string_concat(config_path, DIR_SEP_S, file, NULL);
+	X509_EXTENSION *ex;
+	X509V3_CTX ctx;
 
-	fd = fopen(filepath, "rb");
-	if (fd) {
-		fseek(fd, 0, SEEK_END);
-		size = ftell(fd);
-		fseek(fd, 0, SEEK_SET);
+	/* No configuration database */
+	X509V3_set_ctx_nodb(&ctx);
 
-		// 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);
+	X509V3_set_ctx(&ctx, NULL, cert, NULL, NULL, 0);
+	ex = X509V3_EXT_conf_nid(NULL, &ctx, nid, value);
+	if (!ex) {
+		debug_info("ERROR: X509V3_EXT_conf_nid(%d, %s) failed", nid, value);
+		return 0;
 	}
 
-	free(filepath);
+	X509_add_ext(cert, ex, -1);
+	X509_EXTENSION_free(ex);
 
-	/* Add it to the key_data_t structure */
-	if (success) {
-		data->data = (uint8_t*) content;
-		data->size = size;
-	}
-
-	return success;
+	return 1;
 }
 #endif
 
@@ -678,7 +393,7 @@ static int userpref_get_file_contents(const char *file, key_data_t * data)
  *
  * @return 1 if keys were successfully generated, 0 otherwise
  */
-static userpref_error_t userpref_device_record_gen_keys_and_cert(const char* udid)
+userpref_error_t pair_record_generate_keys_and_certs(plist_t pair_record)
 {
 	userpref_error_t ret = USERPREF_E_SSL_ERROR;
 
@@ -687,7 +402,8 @@ static userpref_error_t userpref_device_record_gen_keys_and_cert(const char* udi
 	key_data_t host_key_pem = { NULL, 0 };
 	key_data_t host_cert_pem = { NULL, 0 };
 
-	debug_info("generating keys and certificates");
+	debug_info("Generating keys and certificates...");
+
 #ifdef HAVE_OPENSSL
 	BIGNUM *e = BN_new();
 	RSA* root_keypair = RSA_new();
@@ -719,11 +435,7 @@ static userpref_error_t userpref_device_record_gen_keys_and_cert(const char* udi
 		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);
+		X509_add_ext_helper(root_cert, NID_basic_constraints, (char*)"critical,CA:TRUE");
 
 		/* set key validity */
 		ASN1_TIME* asn1time = ASN1_TIME_new();
@@ -735,6 +447,7 @@ static userpref_error_t userpref_device_record_gen_keys_and_cert(const char* udi
 
 		/* 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());
 	}
@@ -752,17 +465,10 @@ static userpref_error_t userpref_device_record_gen_keys_and_cert(const char* udi
 		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);
+		X509_add_ext_helper(host_cert, NID_basic_constraints, (char*)"critical,CA:FALSE");
 
 		/* 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);
+		X509_add_ext_helper(host_cert, NID_key_usage, (char*)"critical,digitalSignature,keyEncipherment");
 
 		/* set key validity */
 		ASN1_TIME* asn1time = ASN1_TIME_new();
@@ -907,8 +613,11 @@ static userpref_error_t userpref_device_record_gen_keys_and_cert(const char* udi
 		NULL != host_cert_pem.data && 0 != host_cert_pem.size)
 		ret = USERPREF_E_SUCCESS;
 
-	/* store values in config file */
-	userpref_device_record_set_keys_and_certs(udid, &root_key_pem, &root_cert_pem, &host_key_pem, &host_cert_pem);
+	/* now set keys and certificates */
+	pair_record_set_item_from_key_data(pair_record, USERPREF_HOST_PRIVATE_KEY_KEY, &host_key_pem);
+	pair_record_set_item_from_key_data(pair_record, USERPREF_HOST_CERTIFICATE_KEY, &root_cert_pem);
+	pair_record_set_item_from_key_data(pair_record, USERPREF_ROOT_PRIVATE_KEY_KEY, &root_key_pem);
+	pair_record_set_item_from_key_data(pair_record, USERPREF_ROOT_CERTIFICATE_KEY, &host_cert_pem);
 
 	if (root_key_pem.data)
 		free(root_key_pem.data);
@@ -923,6 +632,284 @@ static userpref_error_t userpref_device_record_gen_keys_and_cert(const char* udi
 }
 
 /**
+ * Generates the device certificate from the public key as well as the host
+ * and root certificates.
+ *
+ * @param pair_record The pair record to use for lookup of key pairs
+ * @param public_key The public key of the device to use for generation.
+ *
+ * @return USERPREF_E_SUCCESS on success, USERPREF_E_INVALID_ARG when a
+ *  parameter is NULL, USERPREF_E_INVALID_CONF if the internal configuration
+ *  system failed, USERPREF_E_SSL_ERROR if the certificates could not be
+ *  generated
+ */
+userpref_error_t pair_record_generate_from_device_public_key(plist_t pair_record, key_data_t public_key)
+{
+	if (!pair_record || !public_key.data)
+		return USERPREF_E_INVALID_ARG;
+
+	userpref_error_t uret = USERPREF_E_UNKNOWN_ERROR;
+
+#ifdef HAVE_OPENSSL
+	BIO *membio = BIO_new_mem_buf(public_key.data, public_key.size);
+	RSA *pubkey = NULL;
+	if (!PEM_read_bio_RSAPublicKey(membio, &pubkey, NULL, NULL)) {
+		debug_info("Could not read public key");
+	}
+	BIO_free(membio);
+
+	/* now generate certificates */
+	key_data_t root_privkey, host_privkey;
+	key_data_t root_cert, host_cert;
+
+	X509* dev_cert = X509_new();
+
+	root_cert.data = NULL;
+	root_cert.size = 0;
+	host_cert.data = NULL;
+	host_cert.size = 0;
+
+	root_privkey.data = NULL;
+	root_privkey.size = 0;
+	host_privkey.data = NULL;
+	host_privkey.size = 0;
+
+	uret = pair_record_import_key_with_name(pair_record, USERPREF_ROOT_CERTIFICATE_KEY, &root_cert);
+	uret = pair_record_import_key_with_name(pair_record, USERPREF_HOST_CERTIFICATE_KEY, &host_cert);
+	uret = pair_record_import_key_with_name(pair_record, USERPREF_ROOT_PRIVATE_KEY_KEY, &root_privkey);
+	uret = pair_record_import_key_with_name(pair_record, USERPREF_HOST_PRIVATE_KEY_KEY, &host_privkey);
+
+	if (USERPREF_E_SUCCESS == uret) {
+		/* generate device certificate */
+		ASN1_INTEGER* sn = ASN1_INTEGER_new();
+		ASN1_INTEGER_set(sn, 0);
+		X509_set_serialNumber(dev_cert, sn);
+		ASN1_INTEGER_free(sn);
+		X509_set_version(dev_cert, 2);
+
+		X509_add_ext_helper(dev_cert, NID_basic_constraints, (char*)"critical,CA:FALSE");
+
+		ASN1_TIME* asn1time = ASN1_TIME_new();
+		ASN1_TIME_set(asn1time, time(NULL));
+		X509_set_notBefore(dev_cert, asn1time);
+		ASN1_TIME_set(asn1time, time(NULL) + (60 * 60 * 24 * 365 * 10));
+		X509_set_notAfter(dev_cert, asn1time);
+		ASN1_TIME_free(asn1time);
+
+		/* read root certificate */
+		BIO* membp;
+		X509* rootCert = NULL;
+		membp = BIO_new_mem_buf(root_cert.data, root_cert.size);
+		PEM_read_bio_X509(membp, &rootCert, NULL, NULL);
+		BIO_free(membp);
+		if (!rootCert) {
+			debug_info("Could not read RootCertificate");
+		} else {
+			debug_info("RootCertificate loaded");
+			EVP_PKEY* pkey = EVP_PKEY_new();
+			EVP_PKEY_assign_RSA(pkey, pubkey);
+			X509_set_pubkey(dev_cert, pkey);
+			EVP_PKEY_free(pkey);
+			X509_free(rootCert);
+		}
+
+		X509_add_ext_helper(dev_cert, NID_subject_key_identifier, (char*)"hash");
+		X509_add_ext_helper(dev_cert, NID_key_usage, (char*)"critical,digitalSignature,keyEncipherment");
+
+		/* read root private key */
+		EVP_PKEY* rootPriv = NULL;
+		membp = BIO_new_mem_buf(root_privkey.data, root_privkey.size);
+		PEM_read_bio_PrivateKey(membp, &rootPriv, NULL, NULL);
+		BIO_free(membp);
+		if (!rootPriv) {
+			debug_info("Could not read RootPrivateKey");
+		} else {
+			debug_info("RootPrivateKey loaded");
+			if (X509_sign(dev_cert, rootPriv, EVP_sha1())) {
+				uret = USERPREF_E_SUCCESS;
+			} else {
+				debug_info("signing failed");
+			}
+			EVP_PKEY_free(rootPriv);
+		}
+
+		if (USERPREF_E_SUCCESS == uret) {
+			/* if everything went well, export in PEM format */
+			key_data_t pem_root_cert = { NULL, 0 };
+			key_data_t pem_host_cert = { NULL, 0 };
+
+			uret = pair_record_import_key_with_name(pair_record, USERPREF_ROOT_CERTIFICATE_KEY, &pem_root_cert);
+			uret = pair_record_import_key_with_name(pair_record, USERPREF_HOST_CERTIFICATE_KEY, &pem_host_cert);
+
+			if (USERPREF_E_SUCCESS == uret) {
+				/* set new keys and certs in pair record */
+				membp = BIO_new(BIO_s_mem());
+				if (membp && PEM_write_bio_X509(membp, dev_cert) > 0) {
+					void *datap;
+					int size = BIO_get_mem_data(membp, &datap);
+					plist_dict_set_item(pair_record, USERPREF_DEVICE_CERTIFICATE_KEY, plist_new_data(datap, size));
+				}
+				if (membp)
+					BIO_free(membp);
+
+				plist_dict_set_item(pair_record, USERPREF_HOST_CERTIFICATE_KEY, plist_new_data((char*)pem_host_cert.data, pem_host_cert.size));
+				plist_dict_set_item(pair_record, USERPREF_ROOT_CERTIFICATE_KEY, plist_new_data((char*)pem_root_cert.data, pem_root_cert.size));
+				plist_dict_set_item(pair_record, USERPREF_ROOT_PRIVATE_KEY_KEY, plist_new_data((char*)root_privkey.data, root_privkey.size));
+				plist_dict_set_item(pair_record, USERPREF_HOST_PRIVATE_KEY_KEY, plist_new_data((char*)host_privkey.data, host_privkey.size));
+
+				free(pem_root_cert.data);
+				free(pem_host_cert.data);
+			}
+		}
+	}
+	X509V3_EXT_cleanup();
+	X509_free(dev_cert);
+
+	if (root_cert.data)
+		free(root_cert.data);
+	if (host_cert.data)
+		free(host_cert.data);
+	if (root_privkey.data)
+		free(root_privkey.data);
+	if (host_privkey.data)
+		free(host_privkey.data);
+#else
+	gnutls_datum_t modulus = { NULL, 0 };
+	gnutls_datum_t exponent = { NULL, 0 };
+
+	/* now decode the PEM encoded key */
+	gnutls_datum_t der_pub_key;
+	if (GNUTLS_E_SUCCESS == gnutls_pem_base64_decode_alloc("RSA PUBLIC KEY", &public_key, &der_pub_key)) {
+
+		/* initalize asn.1 parser */
+		ASN1_TYPE pkcs1 = ASN1_TYPE_EMPTY;
+		if (ASN1_SUCCESS == asn1_array2tree(pkcs1_asn1_tab, &pkcs1, NULL)) {
+
+			ASN1_TYPE asn1_pub_key = ASN1_TYPE_EMPTY;
+			asn1_create_element(pkcs1, "PKCS1.RSAPublicKey", &asn1_pub_key);
+
+			if (ASN1_SUCCESS == asn1_der_decoding(&asn1_pub_key, der_pub_key.data, der_pub_key.size, NULL)) {
+
+				/* get size to read */
+				int ret1 = asn1_read_value(asn1_pub_key, "modulus", NULL, (int*)&modulus.size);
+				int ret2 = asn1_read_value(asn1_pub_key, "publicExponent", NULL, (int*)&exponent.size);
+
+				modulus.data = gnutls_malloc(modulus.size);
+				exponent.data = gnutls_malloc(exponent.size);
+
+				ret1 = asn1_read_value(asn1_pub_key, "modulus", modulus.data, (int*)&modulus.size);
+				ret2 = asn1_read_value(asn1_pub_key, "publicExponent", exponent.data, (int*)&exponent.size);
+				if (ASN1_SUCCESS == ret1 && ASN1_SUCCESS == ret2)
+					uret = USERPREF_E_SUCCESS;
+			}
+			if (asn1_pub_key)
+				asn1_delete_structure(&asn1_pub_key);
+		}
+		if (pkcs1)
+			asn1_delete_structure(&pkcs1);
+	}
+
+	/* now generate certificates */
+	if (USERPREF_E_SUCCESS == uret && 0 != modulus.size && 0 != exponent.size) {
+
+		gnutls_global_init();
+		gnutls_datum_t essentially_null = { (unsigned char*)strdup("abababababababab"), strlen("abababababababab") };
+
+		gnutls_x509_privkey_t fake_privkey, root_privkey, host_privkey;
+		gnutls_x509_crt_t dev_cert, root_cert, host_cert;
+
+		gnutls_x509_privkey_init(&fake_privkey);
+		gnutls_x509_privkey_init(&root_privkey);
+		gnutls_x509_privkey_init(&host_privkey);
+
+		gnutls_x509_crt_init(&dev_cert);
+		gnutls_x509_crt_init(&root_cert);
+		gnutls_x509_crt_init(&host_cert);
+
+		if (GNUTLS_E_SUCCESS ==
+			gnutls_x509_privkey_import_rsa_raw(fake_privkey, &modulus, &exponent, &essentially_null, &essentially_null,
+											   &essentially_null, &essentially_null)) {
+
+			uret = pair_record_import_key_with_name(pair_record, USERPREF_ROOT_CERTIFICATE_KEY, root_cert);
+			uret = pair_record_import_key_with_name(pair_record, USERPREF_HOST_CERTIFICATE_KEY, host_cert);
+			uret = pair_record_import_key_with_name(pair_record, USERPREF_ROOT_PRIVATE_KEY_KEY, root_privkey);
+			uret = pair_record_import_key_with_name(pair_record, USERPREF_HOST_PRIVATE_KEY_KEY, host_privkey);
+
+			if (USERPREF_E_SUCCESS == uret) {
+				/* generate device certificate */
+				gnutls_x509_crt_set_key(dev_cert, fake_privkey);
+				gnutls_x509_crt_set_serial(dev_cert, "\x00", 1);
+				gnutls_x509_crt_set_version(dev_cert, 3);
+				gnutls_x509_crt_set_ca_status(dev_cert, 0);
+				gnutls_x509_crt_set_activation_time(dev_cert, time(NULL));
+				gnutls_x509_crt_set_expiration_time(dev_cert, time(NULL) + (60 * 60 * 24 * 365 * 10));
+
+				/* use custom hash generation for compatibility with the "Apple ecosystem" */
+				const gnutls_digest_algorithm_t dig_sha1 = GNUTLS_DIG_SHA1;
+				size_t hash_size = gnutls_hash_get_len(dig_sha1);
+				unsigned char hash[hash_size];
+				if (gnutls_hash_fast(dig_sha1, der_pub_key.data, der_pub_key.size, (unsigned char*)&hash) < 0) {
+					debug_info("ERROR: Failed to generate SHA1 for public key");
+				} else {
+					gnutls_x509_crt_set_subject_key_id(dev_cert, hash, hash_size);
+				}
+
+				gnutls_x509_crt_set_key_usage(dev_cert, GNUTLS_KEY_DIGITAL_SIGNATURE | GNUTLS_KEY_KEY_ENCIPHERMENT);
+				gnutls_x509_crt_sign(dev_cert, root_cert, root_privkey);
+
+				if (LOCKDOWN_E_SUCCESS == ret) {
+					/* if everything went well, export in PEM format */
+					size_t export_size = 0;
+					gnutls_datum_t dev_pem = { NULL, 0 };
+					gnutls_x509_crt_export(dev_cert, GNUTLS_X509_FMT_PEM, NULL, &export_size);
+					dev_pem.data = gnutls_malloc(export_size);
+					gnutls_x509_crt_export(dev_cert, GNUTLS_X509_FMT_PEM, dev_pem.data, &export_size);
+					dev_pem.size = export_size;
+
+					gnutls_datum_t pem_root_cert = { NULL, 0 };
+					gnutls_datum_t pem_host_cert = { NULL, 0 };
+
+					uret = pair_record_import_key_with_name(pair_record, USERPREF_ROOT_CERTIFICATE_KEY, &pem_root_cert);
+					uret = pair_record_import_key_with_name(pair_record, USERPREF_HOST_CERTIFICATE_KEY, &pem_host_cert);
+
+					if (USERPREF_E_SUCCESS == uret) {
+						/* set new keys and certs in pair record */
+						plist_dict_set_item(pair_record, USERPREF_DEVICE_CERTIFICATE_KEY, plist_new_data(dev_pem.data, dev_pem.size));
+						plist_dict_set_item(pair_record, USERPREF_HOST_CERTIFICATE_KEY, plist_new_data(pem_host_cert.data, pem_host_cert.size));
+						plist_dict_set_item(pair_record, USERPREF_ROOT_CERTIFICATE_KEY, plist_new_data(pem_root_cert.data, pem_root_cert.size));
+						plist_dict_set_item(pair_record, USERPREF_ROOT_PRIVATE_KEY_KEY, plist_new_data(root_privkey.data, root_privkey.size));
+						plist_dict_set_item(pair_record, USERPREF_HOST_PRIVATE_KEY_KEY, plist_new_data(host_privkey.data, host_privkey.size));
+
+						gnutls_free(pem_root_cert.data);
+						gnutls_free(pem_host_cert.data);
+
+						if (dev_pem.data)
+							gnutls_free(dev_pem.data);
+					}
+				}
+			}
+		}
+
+		if (essentially_null.data)
+			free(essentially_null.data);
+
+		gnutls_x509_crt_deinit(dev_cert);
+		gnutls_x509_crt_deinit(root_cert);
+		gnutls_x509_crt_deinit(host_cert);
+		gnutls_x509_privkey_deinit(fake_privkey);
+		gnutls_x509_privkey_deinit(root_privkey);
+		gnutls_x509_privkey_deinit(host_privkey);
+	}
+
+	gnutls_free(modulus.data);
+	gnutls_free(exponent.data);
+
+	gnutls_free(der_pub_key.data);
+#endif
+	return uret;
+}
+
+/**
  * Private function which import the given key into a gnutls structure.
  *
  * @param name The name of the private key to import.
@@ -931,9 +918,9 @@ static userpref_error_t userpref_device_record_gen_keys_and_cert(const char* udi
  * @return 1 if the key was successfully imported.
  */
 #ifdef HAVE_OPENSSL
-static userpref_error_t userpref_device_record_import_key(const char* udid, const char* name, key_data_t* key)
+userpref_error_t pair_record_import_key_with_name(plist_t pair_record, const char* name, key_data_t* key)
 #else
-static userpref_error_t userpref_device_record_import_key(const char* udid, const char* name, gnutls_x509_privkey_t key)
+userpref_error_t pair_record_import_key_with_name(plist_t pair_record, const char* name, gnutls_x509_privkey_t key)
 #endif
 {
 #ifdef HAVE_OPENSSL
@@ -941,33 +928,20 @@ static userpref_error_t userpref_device_record_import_key(const char* udid, cons
 		return USERPREF_E_SUCCESS;
 #endif
 	userpref_error_t ret = USERPREF_E_INVALID_CONF;
-	char* buffer = NULL;
-	uint64_t length = 0;
 
-	plist_t crt = NULL;
-	if (userpref_device_record_get_value(udid, name, &crt)) {
-		if (crt && plist_get_node_type(crt) == PLIST_DATA) {
-			plist_get_data_val(crt, &buffer, &length);
 #ifdef HAVE_OPENSSL
-			key->data = (unsigned char*)malloc(length);
-			memcpy(key->data, buffer, length);
-			key->size = length;
-			ret = USERPREF_E_SUCCESS;
+		ret = pair_record_get_item_as_key_data(pair_record, name, key);
 #else
-			key_data_t pem = { (unsigned char*)buffer, length };
-			if (GNUTLS_E_SUCCESS == gnutls_x509_privkey_import(key, &pem, GNUTLS_X509_FMT_PEM))
-				ret = USERPREF_E_SUCCESS;
-			else
-				ret = USERPREF_E_SSL_ERROR;
-#endif
-		}
-	}
-
-	if (crt)
-		plist_free(crt);
+		key_data_t pem = { NULL, 0 };
+		ret = pair_record_get_item_as_key_data(pair_record, name, pem);
+		if (ret == USERPREF_E_SUCCESS && GNUTLS_E_SUCCESS == gnutls_x509_privkey_import(cert, &pem, GNUTLS_X509_FMT_PEM))
+			ret = USERPREF_E_SUCCESS;
+		else
+			ret = USERPREF_E_SSL_ERROR;
 
-	if (buffer)
-		free(buffer);
+		if (pem.data)
+			free(pem.data);
+#endif
 
 	return ret;
 }
@@ -981,9 +955,9 @@ static userpref_error_t userpref_device_record_import_key(const char* udid, cons
  * @return IDEVICE_E_SUCCESS if the certificate was successfully imported.
  */
 #ifdef HAVE_OPENSSL
-static userpref_error_t userpref_device_record_import_crt(const char* udid, const char* name, key_data_t* cert)
+userpref_error_t pair_record_import_crt_with_name(plist_t pair_record, const char* name, key_data_t* cert)
 #else
-static userpref_error_t userpref_device_record_import_crt(const char* udid, const char* name, gnutls_x509_crt_t cert)
+userpref_error_t pair_record_import_crt_with_name(plist_t pair_record, const char* name, gnutls_x509_crt_t cert)
 #endif
 {
 #ifdef HAVE_OPENSSL
@@ -991,206 +965,83 @@ static userpref_error_t userpref_device_record_import_crt(const char* udid, cons
 		return USERPREF_E_SUCCESS;
 #endif
 	userpref_error_t ret = USERPREF_E_INVALID_CONF;
-	char* buffer = NULL;
-	uint64_t length = 0;
 
-	plist_t crt = NULL;
-	if (userpref_device_record_get_value(udid, name, &crt)) {
-		if (crt && plist_get_node_type(crt) == PLIST_DATA) {
-			plist_get_data_val(crt, &buffer, &length);
 #ifdef HAVE_OPENSSL
-			cert->data = (unsigned char*)malloc(length);
-			memcpy(cert->data, buffer, length);
-			cert->size = length;
-			ret = USERPREF_E_SUCCESS;
+		ret = pair_record_get_item_as_key_data(pair_record, name, cert);
 #else
-			key_data_t pem = { (unsigned char*)buffer, length };
-			if (GNUTLS_E_SUCCESS == gnutls_x509_crt_import(cert, &pem, GNUTLS_X509_FMT_PEM))
-				ret = USERPREF_E_SUCCESS;
-			else
-				ret = USERPREF_E_SSL_ERROR;
-#endif
-		}
-	}
-
-	if (crt)
-		plist_free(crt);
+		key_data_t pem = { NULL, 0 };
+		ret = pair_record_get_item_as_key_data(pair_record, name, pem);
+		if (ret == USERPREF_E_SUCCESS && GNUTLS_E_SUCCESS == gnutls_x509_crt_import(cert, &pem, GNUTLS_X509_FMT_PEM))
+			ret = USERPREF_E_SUCCESS;
+		else
+			ret = USERPREF_E_SSL_ERROR;
 
-	if (buffer)
-		free(buffer);
+		if (pem.data)
+			free(pem.data);
+#endif
 
 	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_device_record_get_keys_and_certs(const char *udid, 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_device_record_get_keys_and_certs(const char *udid, 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 pair_record_get_host_id(plist_t pair_record, char** host_id)
 {
-	userpref_error_t ret = USERPREF_E_SUCCESS;
-
-	if (ret == USERPREF_E_SUCCESS)
-		ret = userpref_device_record_import_key(udid, USERPREF_ROOT_PRIVATE_KEY_KEY, root_privkey);
-
-	if (ret == USERPREF_E_SUCCESS)
-		ret = userpref_device_record_import_key(udid, USERPREF_HOST_PRIVATE_KEY_KEY, host_privkey);
-
-	if (ret == USERPREF_E_SUCCESS)
-		ret = userpref_device_record_import_crt(udid, USERPREF_ROOT_CERTIFICATE_KEY, root_crt);
+	plist_t node = plist_dict_get_item(pair_record, USERPREF_HOST_ID_KEY);
 
-	if (ret == USERPREF_E_SUCCESS)
-		ret = userpref_device_record_import_crt(udid, USERPREF_HOST_CERTIFICATE_KEY, host_crt);
-
-	if (USERPREF_E_SUCCESS != ret) {
-		/* we had problem reading or importing root cert, try with new ones */
-		ret = userpref_device_record_gen_keys_and_cert(udid);
-
-		if (ret == USERPREF_E_SUCCESS)
-			ret = userpref_device_record_import_key(udid, USERPREF_ROOT_PRIVATE_KEY_KEY, root_privkey);
-
-		if (ret == USERPREF_E_SUCCESS)
-			ret = userpref_device_record_import_key(udid, USERPREF_HOST_PRIVATE_KEY_KEY, host_privkey);
+	if (node && plist_get_node_type(node) == PLIST_STRING) {
+		plist_get_string_val(node, host_id);
+	}
 
-		if (ret == USERPREF_E_SUCCESS)
-			ret = userpref_device_record_import_crt(udid, USERPREF_ROOT_CERTIFICATE_KEY, root_crt);
+	return USERPREF_E_SUCCESS;
+}
 
-		if (ret == USERPREF_E_SUCCESS)
-			ret = userpref_device_record_import_crt(udid, USERPREF_ROOT_CERTIFICATE_KEY, host_crt);
-	}
+userpref_error_t pair_record_set_host_id(plist_t pair_record, const char* host_id)
+{
+	plist_dict_set_item(pair_record, USERPREF_HOST_ID_KEY, plist_new_string(host_id));
 
-	return ret;
+	return USERPREF_E_SUCCESS;
 }
 
-/**
- * Function to retrieve certificates encoded in PEM format.
- *
- * @param pem_root_cert The root certificate.
- * @param pem_host_cert The host certificate.
- * @param pem_device_cert The device certificate (optional).
- *
- * @return 1 if the certificates were successfully retrieved, 0 otherwise
- */
-userpref_error_t userpref_device_record_get_certs_as_pem(const char *udid, key_data_t *pem_root_cert, key_data_t *pem_host_cert, key_data_t *pem_device_cert)
+userpref_error_t pair_record_get_item_as_key_data(plist_t pair_record, const char* name, key_data_t *value)
 {
-	if (!udid || !pem_root_cert || !pem_host_cert)
+	if (!pair_record || !value)
 		return USERPREF_E_INVALID_ARG;
 
 	char* buffer = NULL;
 	uint64_t length = 0;
 
-	plist_t root_cert = NULL;
-	plist_t host_cert = NULL;
-	plist_t dev_cert = NULL;
-
-	if (userpref_device_record_get_value(udid, USERPREF_HOST_CERTIFICATE_KEY, &host_cert) &&
-		userpref_device_record_get_value(udid, USERPREF_ROOT_CERTIFICATE_KEY, &root_cert)) {
-		if (host_cert && plist_get_node_type(host_cert) == PLIST_DATA) {
-			plist_get_data_val(host_cert, &buffer, &length);
-			pem_host_cert->data = (unsigned char*)malloc(length);
-			memcpy(pem_host_cert->data, buffer, length);
-			pem_host_cert->size = length;
-			free(buffer);
-			buffer = NULL;
-		}
-		if (root_cert && plist_get_node_type(root_cert) == PLIST_DATA) {
-			plist_get_data_val(root_cert, &buffer, &length);
-			pem_root_cert->data = (unsigned char*)malloc(length);
-			memcpy(pem_root_cert->data, buffer, length);
-			pem_root_cert->size = length;
-			free(buffer);
-			buffer = NULL;
-		}
-
-		if (pem_device_cert) {
-			userpref_device_record_get_value(udid, USERPREF_DEVICE_CERTIFICATE_KEY, &dev_cert);
-			if (dev_cert && plist_get_node_type(dev_cert) == PLIST_DATA) {
-				plist_get_data_val(dev_cert, &buffer, &length);
-				pem_device_cert->data = (unsigned char*)malloc(length);
-				memcpy(pem_device_cert->data, buffer, length);
-				pem_device_cert->size = length;
-				free(buffer);
-				buffer = NULL;
-			}
-		}
-
-		if (root_cert)
-			plist_free(root_cert);
-		if (host_cert)
-			plist_free(host_cert);
-		if (dev_cert)
-			plist_free(dev_cert);
+	plist_t node = plist_dict_get_item(pair_record, name);
 
-		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;
-		}
+	if (node && plist_get_node_type(node) == PLIST_DATA) {
+		plist_get_data_val(node, &buffer, &length);
+		value->data = (unsigned char*)malloc(length);
+		memcpy(value->data, buffer, length);
+		value->size = length;
+		free(buffer);
+		buffer = NULL;
 	}
 
-	if (root_cert)
-		plist_free(root_cert);
-	if (host_cert)
-		plist_free(host_cert);
-	if (dev_cert)
-		plist_free(dev_cert);
+	if (node)
+		plist_free(node);
 
-	debug_info("configuration invalid");
-
-	return USERPREF_E_INVALID_CONF;
+	return USERPREF_E_SUCCESS;
 }
 
-/**
- * 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_device_record_set_keys_and_certs(const char* udid, key_data_t * root_key, key_data_t * root_cert, key_data_t * host_key, key_data_t * host_cert)
+userpref_error_t pair_record_set_item_from_key_data(plist_t pair_record, const char* name, key_data_t *value)
 {
 	userpref_error_t ret = USERPREF_E_SUCCESS;
 
-	debug_info("saving keys and certs for udid %s", udid);
-
-	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);
+	if (!pair_record || !value) {
 		return USERPREF_E_INVALID_ARG;
 	}
 
-	/* now write keys and certificates to disk */
-	if (userpref_device_record_set_value(udid, USERPREF_HOST_PRIVATE_KEY_KEY, plist_new_data((char*)host_key->data, host_key->size)) &&
-		userpref_device_record_set_value(udid, USERPREF_HOST_CERTIFICATE_KEY, plist_new_data((char*)host_cert->data, host_cert->size)) &&
-		userpref_device_record_set_value(udid, USERPREF_ROOT_PRIVATE_KEY_KEY, plist_new_data((char*)root_key->data, root_key->size)) &&
-		userpref_device_record_set_value(udid, USERPREF_ROOT_CERTIFICATE_KEY, plist_new_data((char*)root_cert->data, root_cert->size)))
-	{
-		ret = USERPREF_E_SUCCESS;
-	} else {
-		ret = 1;
+	/* remove any existing item */
+	if (plist_dict_get_item(pair_record, name)) {
+		plist_dict_remove_item(pair_record, name);
 	}
 
+	/* set new item */
+	plist_dict_set_item(pair_record, name, plist_new_data((char*)value->data, value->size));
+
 	return ret;
 }
+
diff --git a/common/userpref.h b/common/userpref.h
index 07fed8d..a39417a 100644
--- a/common/userpref.h
+++ b/common/userpref.h
@@ -69,27 +69,29 @@ typedef gnutls_datum_t key_data_t;
 
 typedef int16_t userpref_error_t;
 
+const char *userpref_get_config_dir();
+int userpref_read_system_buid(char **system_buid);
+userpref_error_t userpref_read_pair_record(const char *udid, plist_t *pair_record);
+userpref_error_t userpref_save_pair_record(const char *udid, plist_t pair_record);
+userpref_error_t userpref_delete_pair_record(const char *udid);
+
+LIBIMOBILEDEVICE_INTERNAL userpref_error_t pair_record_generate_keys_and_certs(plist_t pair_record);
+LIBIMOBILEDEVICE_INTERNAL userpref_error_t pair_record_generate_from_device_public_key(plist_t pair_record, key_data_t public_key);
 #ifdef HAVE_OPENSSL
-LIBIMOBILEDEVICE_INTERNAL userpref_error_t userpref_device_record_get_keys_and_certs(const char *udid, key_data_t* root_privkey, key_data_t* root_crt, key_data_t* host_privkey, key_data_t* host_crt);
+LIBIMOBILEDEVICE_INTERNAL userpref_error_t pair_record_import_key_with_name(plist_t pair_record, const char* name, key_data_t* key);
+LIBIMOBILEDEVICE_INTERNAL userpref_error_t pair_record_import_crt_with_name(plist_t pair_record, const char* name, key_data_t* cert);
 #else
-LIBIMOBILEDEVICE_INTERNAL userpref_error_t userpref_device_record_get_keys_and_certs(const char *udid, gnutls_x509_privkey_t root_privkey, gnutls_x509_crt_t root_crt, gnutls_x509_privkey_t host_privkey, gnutls_x509_crt_t host_crt);
+LIBIMOBILEDEVICE_INTERNAL userpref_error_t pair_record_import_key_with_name(plist_t pair_record, const char* name, gnutls_x509_privkey_t key);
+LIBIMOBILEDEVICE_INTERNAL userpref_error_t pair_record_import_crt_with_name(plist_t pair_record, const char* name, gnutls_x509_crt_t cert);
 #endif
-LIBIMOBILEDEVICE_INTERNAL userpref_error_t userpref_device_record_set_keys_and_certs(const char *udid, 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_device_record_get_certs_as_pem(const char *udid, key_data_t *pem_root_cert, key_data_t *pem_host_cert, key_data_t *pem_device_cert);
 
-LIBIMOBILEDEVICE_INTERNAL userpref_error_t userpref_set_device_record(const char *udid, plist_t device_record);
-userpref_error_t userpref_remove_device_record(const char *udid);
-LIBIMOBILEDEVICE_INTERNAL int userpref_has_device_record(const char *udid);
+userpref_error_t pair_record_get_host_id(plist_t pair_record, char** host_id);
+userpref_error_t pair_record_set_host_id(plist_t pair_record, const char* host_id);
+userpref_error_t pair_record_get_item_as_key_data(plist_t pair_record, const char* name, key_data_t *value);
+userpref_error_t pair_record_set_item_from_key_data(plist_t pair_record, const char* name, key_data_t *value);
 
+/* deprecated */
 userpref_error_t userpref_get_paired_udids(char ***list, unsigned int *count);
-void userpref_device_record_get_host_id(const char *udid, char **host_id);
-void userpref_get_system_buid(char **system_buid);
-const char *userpref_get_config_dir();
-
-userpref_error_t userpref_get_device_record(const char *udid, plist_t *device_record);
-int userpref_get_value(const char *key, plist_t *value);
-int userpref_set_value(const char *key, plist_t value);
-int userpref_device_record_get_value(const char *udid, const char *key, plist_t *value);
-int userpref_device_record_set_value(const char *udid, const char *key, plist_t value);
+LIBIMOBILEDEVICE_INTERNAL int userpref_has_pair_record(const char *udid);
 
 #endif
diff --git a/common/utils.c b/common/utils.c
index 1b207ea..68b23b9 100644
--- a/common/utils.c
+++ b/common/utils.c
@@ -26,6 +26,7 @@
 #include <stdarg.h>
 #include <stdlib.h>
 #include <string.h>
+#include <time.h>
 
 #include "utils.h"
 
@@ -107,6 +108,35 @@ char *string_concat(const char *str, ...)
 	return result;
 }
 
+static int get_rand(int min, int max)
+{
+	int retval = (rand() % (max - min)) + min;
+	return retval;
+}
+
+char *generate_uuid()
+{
+	const char *chars = "ABCDEF0123456789";
+	int i = 0;
+	char *uuid = (char *) malloc(sizeof(char) * 37);
+
+	srand(time(NULL));
+
+	for (i = 0; i < 36; i++) {
+		if (i == 8 || i == 13 || i == 18 || i == 23) {
+			uuid[i] = '-';
+			continue;
+		} else {
+			uuid[i] = chars[get_rand(0, 16)];
+		}
+	}
+
+	/* make it a real string */
+	uuid[36] = '\0';
+
+	return uuid;
+}
+
 void buffer_read_from_filename(const char *filename, char **buffer, uint64_t *length)
 {
 	FILE *f;
diff --git a/common/utils.h b/common/utils.h
index 0e78b3c..c1b6c32 100644
--- a/common/utils.h
+++ b/common/utils.h
@@ -37,6 +37,7 @@
 char *stpcpy(char * s1, const char * s2);
 #endif
 char *string_concat(const char *str, ...);
+char *generate_uuid();
 
 void buffer_read_from_filename(const char *filename, char **buffer, uint64_t *length);
 void buffer_write_to_filename(const char *filename, const char *buffer, uint64_t length);