fix off-by-one error and do not use magic constant of 100 when checking StackPost

[apt.git] / cmdline / apt-key

diff --git a/cmdline/apt-key b/cmdline/apt-key
index 3838fafcd61b18f7957f6423975ac2f65153eaed..2c087acbc667c6da58363d3de35d0d8cb28f3561 100755 (executable)
--- a/cmdline/apt-key
+++ b/cmdline/apt-key
@@ -5,10 +5,14 @@ unset GREP_OPTIONS
 
 # We don't use a secret keyring, of course, but gpg panics and
 # implodes if there isn't one available
-GPG_CMD='gpg --ignore-time-conflict --no-options --no-default-keyring --secret-keyring /etc/apt/secring.gpg'
+SECRETKEYRING="$(mktemp)"
+trap "rm -f '${SECRETKEYRING}'" 0 HUP INT QUIT ILL ABRT FPE SEGV PIPE TERM
+GPG_CMD="gpg --ignore-time-conflict --no-options --no-default-keyring --secret-keyring ${SECRETKEYRING}"
 
 if [ "$(id -u)" -eq 0 ]; then
-       GPG_CMD="$GPG_CMD --trustdb-name /etc/apt/trustdb.gpg"
+       # we could use a tmpfile here too, but creation of this tends to be time-consuming
+       eval $(apt-config shell TRUSTDBDIR Dir::Etc/d)
+       GPG_CMD="$GPG_CMD --trustdb-name ${TRUSTDBDIR}/trustdb.gpg"
 fi
 
 GPG="$GPG_CMD"
@@ -21,6 +25,23 @@ ARCHIVE_KEYRING_URI=""
 ARCHIVE_KEYRING=/usr/share/keyrings/debian-archive-keyring.gpg
 REMOVED_KEYS=/usr/share/keyrings/debian-archive-removed-keys.gpg
 
+requires_root() {
+       if [ "$(id -u)" -ne 0 ]; then
+               echo >&1 "ERROR: This command can only be used by root."
+               exit 1
+       fi
+}
+
+# gpg defaults to mode 0600 for new keyrings. Create one with 0644 instead.
+init_keyring() {
+    for path; do
+        if ! [ -e "$path" ]; then
+            touch -- "$path"
+            chmod 0644 -- "$path"
+        fi
+    done
+}
+
 add_keys_with_verify_against_master_keyring() {
     ADD_KEYRING=$1
     MASTER=$2
@@ -59,13 +80,14 @@ add_keys_with_verify_against_master_keyring() {
 # (otherwise it does not make sense from a security POV)
 net_update() {
     if [ -z "$ARCHIVE_KEYRING_URI" ]; then
-       echo "ERROR: no location for the archive-keyring given"
+       echo >&2 "ERROR: Your distribution is not supported in net-update as no uri for the archive-keyring is set"
        exit 1
     fi
+    requires_root
     # in theory we would need to depend on wget for this, but this feature
     # isn't useable in debian anyway as we have no keyring uri nor a master key
     if ! which wget >/dev/null 2>&1; then
-       echo "ERROR: an installed wget is required for a network-based update"
+       echo >&2 "ERROR: an installed wget is required for a network-based update"
        exit 1
     fi
     if [ ! -d /var/lib/apt/keyrings ]; then
@@ -93,6 +115,7 @@ update() {
        echo >&2 "Is the debian-archive-keyring package installed?"
        exit 1
     fi
+    requires_root
 
     # add new keys from the package;
 
@@ -140,7 +163,7 @@ if [ "$1" = "--keyring" ]; then
         #echo "keyfile given"
        shift
        TRUSTEDFILE="$1"
-       if [ -r "$TRUSTEDFILE" ]; then
+       if [ -r "$TRUSTEDFILE" ] || [ "$2" = 'add' ] || [ "$2" = 'adv' ]; then
                GPG="$GPG --keyring $TRUSTEDFILE --primary-keyring $TRUSTEDFILE"
        else
                echo >&2 "Error: The specified keyring »$TRUSTEDFILE« is missing or not readable"
@@ -184,32 +207,43 @@ fi
 
 case "$command" in
     add)
+        requires_root
+        init_keyring "$TRUSTEDFILE"
         $GPG --quiet --batch --import "$1"
         echo "OK"
         ;;
     del|rm|remove)
+        requires_root
+        init_keyring "$TRUSTEDFILE"
         $GPG --quiet --batch --delete-key --yes "$1"
         echo "OK"
         ;;
     update)
+        init_keyring "$TRUSTEDFILE"
        update
        ;;
     net-update)
+        init_keyring "$TRUSTEDFILE"
        net_update
        ;;
     list)
+        init_keyring "$TRUSTEDFILE"
         $GPG --batch --list-keys
         ;;
     finger*)
+        init_keyring "$TRUSTEDFILE"
         $GPG --batch --fingerprint
         ;;
     export)
+        init_keyring "$TRUSTEDFILE"
         $GPG --armor --export "$1"
         ;;
     exportall)
+        init_keyring "$TRUSTEDFILE"
         $GPG --armor --export
         ;;
     adv*)
+        init_keyring "$TRUSTEDFILE"
         echo "Executing: $GPG $*"
         $GPG $*
         ;;