Fix how file modification check is done, and fix accidental extraneous

[monkeysphere.git] / src / common

diff --git a/src/common b/src/common
index 5d43fa4aa15a44a054037b46c35edf405c122e53..ba7df7320f69275f81e1d80cae4892649f95fcf2 100644 (file)
--- a/src/common
+++ b/src/common
@@ -20,14 +20,10 @@ export ETC
 ########################################################################
 ### UTILITY FUNCTIONS
 
-error() {
-    log "$1"
-    ERR=${2:-'1'}
-}
-
+# failure function.  exits with code 255, unless specified otherwise.
 failure() {
     echo "$1" >&2
-    exit ${2:-'1'}
+    exit ${2:-'255'}
 }
 
 # write output to stderr
@@ -83,11 +79,15 @@ remove_line() {
     file="$1"
     string="$2"
 
-    # if the string is in the file and removed, return 0
+    if [ -z "$file" -o -z "$string" ] ; then
+       return 1
+    fi
+
+    # if the string is in the file...
     if grep -q -F "$string" "$file" 2> /dev/null ; then
+       # remove the line with the string, and return 0
        grep -v -F "$string" "$file" | sponge "$file"
        return 0
-
     # otherwise return 1
     else
        return 1
@@ -115,7 +115,49 @@ translate_ssh_variables() {
 
 # test that a string to conforms to GPG's expiration format
 test_gpg_expire() {
-    echo "$1" | egrep -q "^[0-9][mwy]?$"
+    echo "$1" | egrep -q "^[0-9]+[mwy]?$"
+}
+
+# check that a file is properly owned, and that all it's parent
+# directories are not group/other writable
+check_key_file_permissions() {
+    local user
+    local path
+    local access
+    local gAccess
+    local oAccess
+
+    # function to check that an octal corresponds to writability
+    is_write() {
+       [ "$1" -eq 2 -o "$1" -eq 3 -o "$1" -eq 6 -o "$1" -eq 7 ]
+    }
+
+    user="$1"
+    path="$2"
+
+    # return 0 is path does not exist
+    [ -e "$path" ] || return 0
+
+    owner=$(stat --format '%U' "$path")
+    access=$(stat --format '%a' "$path")
+    gAccess=$(echo "$access" | cut -c2)
+    oAccess=$(echo "$access" | cut -c3)
+
+    # check owner
+    if [ "$owner" != "$user" -a "$owner" != 'root' ] ; then
+       return 1
+    fi
+
+    # check group/other writability
+    if is_write "$gAccess" || is_write "$oAccess" ; then
+       return 2
+    fi
+
+    if [ "$path" = '/' ] ; then
+       return 0
+    else
+       check_key_file_permissions $(dirname "$path")
+    fi
 }
 
 ### CONVERSION UTILITIES
@@ -277,8 +319,6 @@ process_user_id() {
     fi
 
     # loop over all lines in the gpg output and process.
-    # need to do it this way (as opposed to "while read...") so that
-    # variables set in loop will be visible outside of loop
     echo "$gpgOut" | cut -d: -f1,2,5,10,12 | \
     while IFS=: read -r type validity keyid uidfpr usage ; do
        # process based on record type
@@ -409,6 +449,10 @@ process_host_known_hosts() {
        keyid=$(echo "$line" | cut -d: -f2)
 
        sshKey=$(gpg2ssh "$keyid")
+        if [ -z "$sshKey" ] ; then
+            log "  ! key could not be translated."
+            continue
+        fi
 
        # remove the old host key line, and note if removed
        remove_line "$KNOWN_HOSTS" "$sshKey"
@@ -454,6 +498,7 @@ update_known_hosts() {
     local nHosts
     local nHostsOK
     local nHostsBAD
+    local fileCheck
     local host
 
     # the number of hosts specified on command line
@@ -468,6 +513,9 @@ update_known_hosts() {
     # create a lockfile on known_hosts
     lockfile-create "$KNOWN_HOSTS"
 
+    # note pre update file checksum
+    fileCheck=$(md5sum "$KNOWN_HOSTS")
+
     for host ; do
        # process the host
        process_host_known_hosts "$host"
@@ -489,7 +537,7 @@ update_known_hosts() {
     lockfile-remove "$KNOWN_HOSTS"
 
     # note if the known_hosts file was updated
-    if [ "$nHostsOK" -gt 0 -o "$nHostsBAD" -gt 0 ] ; then
+    if [ "$(md5sum "$KNOWN_HOSTS")" != "$fileCheck" ] ; then
        log "known_hosts file updated."
     fi
 
@@ -517,6 +565,11 @@ process_known_hosts() {
 
     hosts=$(meat "$KNOWN_HOSTS" | cut -d ' ' -f 1 | grep -v '^|.*$' | tr , ' ' | tr '\n' ' ')
 
+    if [ -z "$hosts" ] ; then
+       log "no hosts to process."
+       return
+    fi
+
     # take all the hosts from the known_hosts file (first
     # field), grep out all the hashed hosts (lines starting
     # with '|')...
@@ -546,6 +599,10 @@ process_uid_authorized_keys() {
        keyid=$(echo "$line" | cut -d: -f2)
 
        sshKey=$(gpg2ssh "$keyid")
+        if [ -z "$sshKey" ] ; then
+            log "  ! key could not be translated."
+            continue
+        fi
 
        # remove the old host key line
        remove_line "$AUTHORIZED_KEYS" "$sshKey"
@@ -581,6 +638,7 @@ update_authorized_keys() {
     local nIDs
     local nIDsOK
     local nIDsBAD
+    local fileCheck
 
     # the number of ids specified on command line
     nIDs="$#"
@@ -594,6 +652,9 @@ update_authorized_keys() {
     # create a lockfile on authorized_keys
     lockfile-create "$AUTHORIZED_KEYS"
 
+    # note pre update file checksum
+    fileCheck=$(md5sum "$AUTHORIZED_KEYS")
+
     for userID ; do
        # process the user ID, change return code if key not found for
        # user ID
@@ -617,7 +678,7 @@ update_authorized_keys() {
     lockfile-remove "$AUTHORIZED_KEYS"
 
     # note if the authorized_keys file was updated
-    if [ "$nIDsOK" -gt 0 -o "$nIDsBAD" -gt 0 ] ; then
+    if [ "$(md5sum "$AUTHORIZED_KEYS")" != "$fileCheck" ] ; then
        log "authorized_keys file updated."
     fi
 
@@ -640,15 +701,25 @@ update_authorized_keys() {
 # process an authorized_user_ids file for authorized_keys
 process_authorized_user_ids() {
     local line
+    local nline
     local userIDs
 
     authorizedUserIDs="$1"
 
     log "processing authorized_user_ids file..."
 
+    if ! meat "$authorizedUserIDs" > /dev/null ; then
+       log "no user IDs to process."
+       return
+    fi
+
+    nline=0
+
     # extract user IDs from authorized_user_ids file
-    for line in $(seq 1 $(meat "$authorizedUserIDs" | wc -l)) ; do
-       userIDs[$((line-1))]=$(cutline "$line" "$authorizedUserIDs")
+    IFS=$'\n'
+    for line in $(meat "$authorizedUserIDs") ; do
+       userIDs["$nline"]="$line"
+       nline=$((nline+1))
     done
 
     update_authorized_keys "${userIDs[@]}"