From 4979bdd82f85fd8701552f7e9b7abba08bd02359 Mon Sep 17 00:00:00 2001
From: Thomas Haller <thaller@redhat.com>
Date: Mon, 25 Apr 2016 18:14:25 +0200
Subject: core: add nm_utils_get_secret_key() util

---
 src/nm-core-utils.c | 104 +++++++++++++++++++++++++++++-----------------------
 src/nm-core-utils.h |   2 +
 2 files changed, 61 insertions(+), 45 deletions(-)

diff --git a/src/nm-core-utils.c b/src/nm-core-utils.c
index 188e4737af..24d862aff8 100644
--- a/src/nm-core-utils.c
+++ b/src/nm-core-utils.c
@@ -2588,6 +2588,59 @@ nm_utils_is_specific_hostname (const char *name)
 
 /******************************************************************/
 
+char *
+nm_utils_get_secret_key (gsize *out_key_len, GError **error)
+{
+	char *secret_key = NULL;
+	gsize key_len;
+
+	/* Let's try to load a saved secret key first. */
+	if (g_file_get_contents (NMSTATEDIR "/secret_key", &secret_key, &key_len, NULL)) {
+		if (key_len < 16) {
+			g_set_error_literal (error, NM_UTILS_ERROR, NM_UTILS_ERROR_UNKNOWN,
+			                     "Key is too short to be usable");
+			key_len = 0;
+		}
+	} else {
+		int urandom = open ("/dev/urandom", O_RDONLY);
+		mode_t key_mask;
+
+		if (urandom == -1) {
+			g_set_error (error, NM_UTILS_ERROR, NM_UTILS_ERROR_UNKNOWN,
+			             "Can't open /dev/urandom: %s", strerror (errno));
+			key_len = 0;
+			goto out;
+		}
+
+		/* RFC7217 mandates the key SHOULD be at least 128 bits.
+		 * Let's use twice as much. */
+		key_len = 32;
+		secret_key = g_malloc (key_len + 1);
+
+		key_mask = umask (0077);
+		if (read (urandom, secret_key, key_len) == key_len) {
+			secret_key[key_len] = '\0';
+			if (!g_file_set_contents (NMSTATEDIR "/secret_key", secret_key, key_len, error)) {
+				g_prefix_error (error, "Can't write " NMSTATEDIR "/secret_key: ");
+				key_len = 0;
+			}
+		} else {
+			g_set_error_literal (error, NM_UTILS_ERROR, NM_UTILS_ERROR_UNKNOWN,
+			                     "Could not obtain a secret");
+			key_len = 0;
+		}
+		umask (key_mask);
+		close (urandom);
+	}
+
+out:
+	NM_SET_OUT (out_key_len, key_len);
+	if (key_len)
+		return secret_key;
+	g_free (secret_key);
+	return NULL;
+}
+
 /* Returns the "u" (universal/local) bit value for a Modified EUI-64 */
 static gboolean
 get_gre_eui64_u_bit (guint32 addr)
@@ -2773,9 +2826,8 @@ nm_utils_ipv6_addr_set_stable_privacy (struct in6_addr *addr,
                                        guint dad_counter,
                                        GError **error)
 {
-	gchar *secret_key = NULL;
+	gs_free gchar *secret_key = NULL;
 	gsize key_len = 0;
-	gboolean success = FALSE;
 
 	if (dad_counter >= RFC7217_IDGEN_RETRIES) {
 		g_set_error_literal (error, NM_UTILS_ERROR, NM_UTILS_ERROR_UNKNOWN,
@@ -2783,50 +2835,12 @@ nm_utils_ipv6_addr_set_stable_privacy (struct in6_addr *addr,
 		return FALSE;
 	}
 
-	/* Let's try to load a saved secret key first. */
-	if (g_file_get_contents (NMSTATEDIR "/secret_key", &secret_key, &key_len, NULL)) {
-		if (key_len < 16) {
-			g_set_error_literal (error, NM_UTILS_ERROR, NM_UTILS_ERROR_UNKNOWN,
-			                     "Key is too short to be usable");
-			key_len = 0;
-		}
-	} else {
-		int urandom = open ("/dev/urandom", O_RDONLY);
-		mode_t key_mask;
-
-		if (urandom == -1) {
-			g_set_error (error, NM_UTILS_ERROR, NM_UTILS_ERROR_UNKNOWN,
-			             "Can't open /dev/urandom: %s", strerror (errno));
-			return FALSE;
-		}
-
-		/* RFC7217 mandates the key SHOULD be at least 128 bits.
-		 * Let's use twice as much. */
-		key_len = 32;
-		secret_key = g_malloc (key_len);
-
-		key_mask = umask (0077);
-		if (read (urandom, secret_key, key_len) == key_len) {
-			if (!g_file_set_contents (NMSTATEDIR "/secret_key", secret_key, key_len, error)) {
-				g_prefix_error (error, "Can't write " NMSTATEDIR "/secret_key: ");
-				key_len = 0;
-			}
-		} else {
-			g_set_error_literal (error, NM_UTILS_ERROR, NM_UTILS_ERROR_UNKNOWN,
-			                     "Could not obtain a secret");
-			key_len = 0;
-		}
-		umask (key_mask);
-		close (urandom);
-	}
-
-	if (key_len) {
-		success = _set_stable_privacy (addr, ifname, uuid, dad_counter,
-		                               secret_key, key_len, error);
-	}
+	secret_key = nm_utils_get_secret_key (&key_len, error);
+	if (!secret_key)
+		return FALSE;
 
-	g_free (secret_key);
-	return success;
+	return _set_stable_privacy (addr, ifname, uuid, dad_counter,
+	                            secret_key, key_len, error);
 }
 
 /**
diff --git a/src/nm-core-utils.h b/src/nm-core-utils.h
index 486942a22a..82d9424ec5 100644
--- a/src/nm-core-utils.h
+++ b/src/nm-core-utils.h
@@ -307,6 +307,8 @@ const char *nm_utils_ip4_property_path (const char *ifname, const char *property
 
 gboolean nm_utils_is_specific_hostname (const char *name);
 
+char *nm_utils_get_secret_key (gsize *out_key_len, GError **error);
+
 /* IPv6 Interface Identifer helpers */
 
 /**
-- 
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