cherry pick 39a07ec8f2c612a5af234c7713571362f7ca90b4

[apt.git] / cmdline / apt-key

diff --git a/cmdline/apt-key b/cmdline/apt-key
index 7c1aad0cfbb23f501e958bc86d912f4a7edcf593..2c087acbc667c6da58363d3de35d0d8cb28f3561 100755 (executable)
--- a/cmdline/apt-key
+++ b/cmdline/apt-key
@@ -1,49 +1,197 @@
 #!/bin/sh
 
 set -e
 #!/bin/sh
 
 set -e

+unset GREP_OPTIONS

 
 # We don't use a secret keyring, of course, but gpg panics and
 # implodes if there isn't one available
 
 # We don't use a secret keyring, of course, but gpg panics and
 # implodes if there isn't one available

+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}"

 
 

-GPG_CMD="gpg --no-options --no-default-keyring --secret-keyring /etc/apt/secring.gpg --trustdb-name /etc/apt/trustdb.gpg"
-GPG="$GPG_CMD --keyring /etc/apt/trusted.gpg"
+if [ "$(id -u)" -eq 0 ]; then
+       # 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"
+
+MASTER_KEYRING=""
+ARCHIVE_KEYRING_URI=""
+#MASTER_KEYRING=/usr/share/keyrings/debian-master-keyring.gpg
+#ARCHIVE_KEYRING_URI=http://ftp.debian.org/debian/debian-archive-keyring.gpg
+
+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=$2
+    
+    if [ ! -f "$ADD_KEYRING" ]; then
+       echo "ERROR: '$ADD_KEYRING' not found"
+       return
+    fi 
+    if [ ! -f "$MASTER" ]; then
+       echo "ERROR: '$MASTER' not found"
+       return
+    fi

 
 

-ARCHIVE_KEYRING=/usr/share/keyrings/ubuntu-archive-keyring.gpg
-REMOVED_KEYS=/usr/share/keyrings/ubuntu-archive-removed-keys.gpg
+    # when adding new keys, make sure that the archive-master-keyring
+    # is honored. so:
+    #   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_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 "$ARCHIVE_KEYRING_URI" ]; then
+       echo >&2 "ERROR: Your distribution is not supported in net-update as no uri for the archive-keyring is set"
+       exit 1
+    fi
+    requires_root
+    # in theory we would need to depend on wget for this, but this feature
+    # isn't useable in debian anyway as we have no keyring uri nor a master key
+    if ! which wget >/dev/null 2>&1; then
+       echo >&2 "ERROR: an installed wget is required for a network-based update"
+       exit 1
+    fi
+    if [ ! -d /var/lib/apt/keyrings ]; then
+       mkdir -p /var/lib/apt/keyrings
+    fi
+    keyring=/var/lib/apt/keyrings/$(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"
 
 update() {
     if [ ! -f $ARCHIVE_KEYRING ]; then
        echo >&2 "ERROR: Can't find the archive-keyring"

-       echo >&2 "Is the ubuntu-keyring package installed?"
+       echo >&2 "Is the debian-archive-keyring package installed?"

        exit 1
     fi
        exit 1
     fi

+    requires_root

 
 

-    # add new keys
-    $GPG_CMD --quiet --batch --keyring $ARCHIVE_KEYRING --export | $GPG --ignore-time-conflict --import
+    # add new keys from the package;

 
 

-    # remove no-longer used keys
-    keys=`$GPG_CMD --keyring $REMOVED_KEYS --with-colons --list-keys | grep ^pub | cut -d: -f5`
-    for key in $keys; do
-       if $GPG --list-keys --with-colons | grep ^pub | cut -d: -f5 | grep -q $key; then
-           $GPG --quiet --batch --delete-key --yes ${key}
-       fi
-    done
+    # we do not use add_keys_with_verify_against_master_keyring here,
+    # because "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 | $GPG --import
+
+    if [ -r "$REMOVED_KEYS" ]; then
+       # remove no-longer supported/used keys
+       keys=`$GPG_CMD --keyring $REMOVED_KEYS --with-colons --list-keys | grep ^pub | cut -d: -f5`
+       for key in $keys; do
+           if $GPG --list-keys --with-colons | grep ^pub | cut -d: -f5 | grep -q $key; then
+               $GPG --quiet --batch --delete-key --yes ${key}
+           fi
+       done
+    else
+       echo "Warning: removed keys keyring  $REMOVED_KEYS missing or not readable" >&2
+    fi

 }
 
 }
 

+

 usage() {
 usage() {

-    echo "Usage: apt-key [command] [arguments]"
+    echo "Usage: apt-key [--keyring file] [command] [arguments]"

     echo
     echo "Manage apt's list of trusted keys"
     echo
     echo "  apt-key add <file>          - add the key contained in <file> ('-' for stdin)"
     echo "  apt-key del <keyid>         - remove the key <keyid>"
     echo
     echo "Manage apt's list of trusted keys"
     echo
     echo "  apt-key add <file>          - add the key contained in <file> ('-' for stdin)"
     echo "  apt-key del <keyid>         - remove the key <keyid>"

+    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 update              - update keys using the keyring package"

+    echo "  apt-key net-update          - update keys using the network"

     echo "  apt-key list                - list keys"
     echo "  apt-key list                - list keys"

+    echo "  apt-key finger              - list fingerprints"
+    echo "  apt-key adv                 - pass advanced options to gpg (download key)"

     echo
     echo

+    echo "If no specific keyring file is given the command applies to all keyring files."

 }
 
 }
 

+# Determine on which keyring we want to work
+if [ "$1" = "--keyring" ]; then
+        #echo "keyfile given"
+       shift
+       TRUSTEDFILE="$1"
+       if [ -r "$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"
+               exit 1
+       fi
+       shift
+# otherwise use the default
+else
+       #echo "generate list"
+       TRUSTEDFILE="/etc/apt/trusted.gpg"
+       eval $(apt-config shell TRUSTEDFILE Apt::GPGV::TrustedKeyring)
+       eval $(apt-config shell TRUSTEDFILE Dir::Etc::Trusted/f)
+       if [ -r "$TRUSTEDFILE" ]; then
+               GPG="$GPG --keyring $TRUSTEDFILE"
+       fi
+       GPG="$GPG --primary-keyring $TRUSTEDFILE"
+       TRUSTEDPARTS="/etc/apt/trusted.gpg.d"
+       eval $(apt-config shell TRUSTEDPARTS Dir::Etc::TrustedParts/d)
+       if [ -d "$TRUSTEDPARTS" ]; then
+               #echo "parts active"
+               for trusted in $(run-parts --list $TRUSTEDPARTS --regex '^.*\.gpg$'); do
+                       #echo "part -> $trusted"
+                       GPG="$GPG --keyring $trusted"
+               done
+       fi
+fi
+#echo "COMMAND: $GPG"
+

 command="$1"
 if [ -z "$command" ]; then
     usage
 command="$1"
 if [ -z "$command" ]; then
     usage


@@ -59,23 +207,43 @@ fi
 
 case "$command" in
     add)
 
 case "$command" in
     add)

+        requires_root
+        init_keyring "$TRUSTEDFILE"

         $GPG --quiet --batch --import "$1"
         echo "OK"
         ;;
     del|rm|remove)
         $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)
         $GPG --quiet --batch --delete-key --yes "$1"
         echo "OK"
         ;;
     update)

+        init_keyring "$TRUSTEDFILE"

        update
        ;;
        update
        ;;

+    net-update)
+        init_keyring "$TRUSTEDFILE"
+       net_update
+       ;;

     list)
     list)

+        init_keyring "$TRUSTEDFILE"

         $GPG --batch --list-keys
         ;;
     finger*)
         $GPG --batch --list-keys
         ;;
     finger*)

+        init_keyring "$TRUSTEDFILE"

         $GPG --batch --fingerprint
         ;;
         $GPG --batch --fingerprint
         ;;

+    export)
+        init_keyring "$TRUSTEDFILE"
+        $GPG --armor --export "$1"
+        ;;
+    exportall)
+        init_keyring "$TRUSTEDFILE"
+        $GPG --armor --export
+        ;;

     adv*)
     adv*)

+        init_keyring "$TRUSTEDFILE"

         echo "Executing: $GPG $*"
         $GPG $*
         ;;
         echo "Executing: $GPG $*"
         $GPG $*
         ;;