X-Git-Url: https://git.saurik.com/apt.git/blobdiff_plain/1b7fe0e12c7553e0efc90ca6922caecb8d5cbb07..397d56f56b3ffaf38df57571c11f0699e2810902:/cmdline/apt-key?ds=sidebyside

diff --git a/cmdline/apt-key b/cmdline/apt-key
index 860895ae2..de04d16da 100755
--- a/cmdline/apt-key
+++ b/cmdline/apt-key
@@ -12,6 +12,7 @@ GPG="$GPG_CMD --keyring /etc/apt/trusted.gpg"
 MASTER_KEYRING=/usr/share/keyrings/ubuntu-master-keyring.gpg
 ARCHIVE_KEYRING=/usr/share/keyrings/ubuntu-archive-keyring.gpg
 REMOVED_KEYS=/usr/share/keyrings/ubuntu-archive-removed-keys.gpg
+ARCHIVE_KEYRING_URI=http://archive.ubuntu.com/ubuntu/project/ubuntu-archive-keyring.gpg
 
 add_keys_with_verify_against_master_keyring() {
     ADD_KEYRING=$1
@@ -28,20 +29,50 @@ add_keys_with_verify_against_master_keyring() {
 
     # when adding new keys, make sure that the archive-master-keyring
     # is honored. so:
-    #   all keys that are exported and have the name
-    #   "Ubuntu Archive Automatic Signing Key" must have a valid signature
-    #   from a key in the ubuntu-master-keyring
+    #   all keys that are exported must have a valid signature
+    #   from a key in the $distro-master-keyring
     add_keys=`$GPG_CMD --keyring $ADD_KEYRING --with-colons --list-keys | grep ^pub | cut -d: -f5`
     master_keys=`$GPG_CMD --keyring $MASTER --with-colons --list-keys | grep ^pub | cut -d: -f5`
     for add_key in $add_keys; do
+	ADDED=0
 	for master_key in $master_keys; do
-	    if $GPG --list-sigs --with-colons $add_key | grep ^sig | cut -d: -f5 | grep -q $master_key; then
-		$GPG_CMD --quiet --batch --keyring $ARCHIVE_KEYRING --export $add_key | $GPG --import
+	    if $GPG_CMD --keyring $ADD_KEYRING --list-sigs --with-colons $add_key | grep ^sig | cut -d: -f5 | grep -q $master_key; then
+		$GPG_CMD --quiet --batch --keyring $ADD_KEYRING --export $add_key | $GPG --import
+		ADDED=1
 	    fi
 	done
+	if [ $ADDED = 0 ]; then
+	    echo >&2 "Key '$add_key' not added. It is not signed with a master key"
+	fi
     done
 }
 
+# update the current archive signing keyring from a network URI
+# the archive-keyring keys needs to be signed with the master key
+# (otherwise it does not make sense from a security POV)
+net_update() {
+    if [ -z "$ARCHIVE_KEYRING_URI" ]; then
+	echo "ERROR: no location for the archive-keyring given" 
+    fi
+    if [ ! -d /var/lib/apt/keyrings ]; then
+	mkdir -p /var/lib/apt/keyrings
+    fi
+    keyring=/var/lib/apt/keyrings/$(basename $ARCHIVE_KEYRING)
+    old_mtime=0
+    if [ -e $keyring ]; then
+	old_mtime=$(stat -c %Y $keyring)
+    fi
+    (cd  /var/lib/apt/keyrings; wget -q -N $ARCHIVE_KEYRING_URI)
+    if [ ! -e $keyring ]; then
+	return
+    fi
+    new_mtime=$(stat -c %Y $keyring)
+    if [ $new_mtime -ne $old_mtime ]; then
+	echo "Checking for new archive signing keys now"
+	add_keys_with_verify_against_master_keyring $keyring $MASTER_KEYRING
+    fi
+}
+
 update() {
     if [ ! -f $ARCHIVE_KEYRING ]; then
 	echo >&2 "ERROR: Can't find the archive-keyring"
@@ -49,13 +80,14 @@ update() {
 	exit 1
     fi
 
-    # add new keys, if no MASTER_KEYRING is used, use the traditional
-    # way
-    if [ -z "$MASTER_KEYRING" ]; then
-	$GPG_CMD --quiet --batch --keyring $ARCHIVE_KEYRING --export | $GPG --import
-    else
-	add_keys_with_verify_against_master_keyring $ARCHIVE_KEYRING $MASTER_KEYRING
-    fi
+    # add new keys from the package;
+
+    # we do not use add_keys_with_verify_against_master_keyring here,
+    # because we "update" is run on regular package updates.  A
+    # attacker might as well replace the master-archive-keyring file
+    # in the package and add his own keys. so this check wouldn't
+    # add any security. we *need* this check on net-update though
+    $GPG_CMD --quiet --batch --keyring $ARCHIVE_KEYRING --export | $GPG --import
 
     # remove no-longer supported/used keys
     keys=`$GPG_CMD --keyring $REMOVED_KEYS --with-colons --list-keys | grep ^pub | cut -d: -f5`
@@ -77,6 +109,7 @@ usage() {
     echo "  apt-key export <keyid>      - output the key <keyid>"
     echo "  apt-key exportall           - output all trusted keys"
     echo "  apt-key update              - update keys using the keyring package"
+    echo "  apt-key net-update          - update keys using the network"
     echo "  apt-key list                - list keys"
     echo
 }
@@ -106,6 +139,9 @@ case "$command" in
     update)
 	update
 	;;
+    net-update)
+	net_update
+	;;
     list)
         $GPG --batch --list-keys
         ;;