git.marmaro.de Git - mmh/blob - uip/mhsign.sh

   1 #!/bin/sh
   2 # Based on mhsign 1.1.0.9 2007/05/30 14:48:40 by Neil Rickert
   3 # Adjusted to mmh by markus schnalke <meillo@marmaro.de>, 2012-07
   4
   5
   6 # mhsign:
   7 #   -encrypt:  Encrypt to recipients of message. This implies signing.
   8 #   -mime:     Use MIME pgp standard.  For signature, trailing blanks
   9 #              will be removed and any "From " line will be indented for
  10 #              best compatibility. Enforced for multipart messages.
  11
  12 usage="Usage: mhsign [-encrypt] [-mime] [-Version] [-help] file"
  13
  14 # defaults
  15 usemime=n
  16 function=sign
  17
  18
  19 # find out the signing key
  20 userid="$MMHPGPKEY"
  21 if [ -z "$userid" ] ; then
  22         userid="`mhparam pgpkey`"
  23 fi
  24 if [ -z "$userid" ] ; then
  25         userid="`gpg --list-secret-keys --with-colons --fixed-list-mode \
  26                                 2>/dev/null |
  27                         grep '^sec' | sort -t: -k3,3nr -k 6,6nr |
  28                         awk -F: '
  29                                 $7=="" || $7 > "'"\`date +%s\`"'" {
  30                                         print $5; exit;
  31                                 }
  32                         '`"
  33 fi
  34 if [ -z "$userid" ] ; then
  35         echo "No secret key found" >&2
  36         exit 1
  37 fi
  38
  39 # find out the file of recipient key exceptions (for encrypt only)
  40 keyfile="${MMH:-$HOME/.mmh}/pgpkeys"
  41 if [ ! -r "$keyfile" ] ; then
  42         keyfile="${GNUPGHOME:-$HOME/.gnupg}/pgpkeys"
  43         if [ ! -r "$keyfile" ] ; then
  44                 keyfile=/dev/null
  45         fi
  46 fi
  47
  48 # prepend the default options from the profile
  49 set -- `mhparam -nocomp ${0##*/}` "$@"
  50
  51 while : ; do
  52         case "$1" in
  53         -e*)
  54                 function=encrypt
  55                 ;;
  56         -m*)
  57                 usemime=y
  58                 ;;
  59         -V*)
  60                 echo "mhsign has no own version number, thus this instead:"
  61                 folder -Version
  62                 exit 0
  63                 ;;
  64         -h*|-*)
  65                 echo "$usage" >&2
  66                 exit 1
  67                 ;;
  68         *)
  69                 break
  70         esac
  71         shift
  72 done
  73
  74 if [ $# -ne 1 ] ; then
  75         echo "$usage" >&2
  76         exit 1
  77 fi
  78
  79 TEMP=/tmp/${0##*/}.$$
  80 umask 077
  81 mkdir $TEMP || exit 1
  82 trap "rm -rf $TEMP" 0 1 2 15
  83
  84 ### lookupkeyfile address -- lookup one address in our database
  85 lookupkeyfile() {
  86         key=`grep -i "^[^#].*[  ]$1\$" "$keyfile" 2>/dev/null`
  87         if [ $? != 0 ] ; then
  88                 return 1
  89         fi
  90         echo "$key" | sed 's/[  ].*//;q'
  91         return 0
  92 }
  93
  94 ### lookupkeyring address -- lookup one address in keyring
  95 lookupkeyring() {
  96         key=`gpg --list-keys --with-colons "<$1>" 2>/dev/null`
  97         if [ $? != 0 ] ; then
  98                 return 1
  99         fi
 100         echo "$key" | sed -n '/^pub:[^idre]:/{p;q;}' | cut -d: -f5
 101         return 0
 102 }
 103
 104 ### lookupkeys file -- set $KL to list of recipient keys
 105 lookupkeys() {
 106         KL=
 107         status=0
 108         if whom -ali -notocc -bcc "$1" >/dev/null ; then
 109                 echo "Encryption is not supported for BCCs" >&2
 110                 return 1
 111         fi
 112
 113         # extract the actual address
 114         format='%<{error}%{error}: %{text}%|%(addr{text})%>'
 115         addresses=`whom -ali -tocc -nobcc "$1" |sed 's_$_,_'`
 116         addresses=`%libdir%/ap -form "=$format" "$addresses"`
 117
 118         for i in $addresses ; do
 119                 case "$i" in
 120                 '|'*)   echo "Ignoring pipe address" >&2
 121                         continue ;;
 122                 *@*)    ;;
 123                 *)      i="$i@`hostname -f`" ;;
 124                 esac
 125                 if k=`lookupkeyfile "$i"` ; then
 126                         KL="$KL $k"
 127                 elif k=`lookupkeyring "$i"` ; then
 128                         KL="$KL $k"
 129                 else
 130                         echo "Could not find key for <$i>" >&2
 131                         status=1
 132                 fi
 133         done
 134         return $status
 135 }
 136
 137 ### getheader headername msgfile
 138 getheader() {
 139         HDR=`sed -n -e '/^-*$/q' -e 's/^\([^    :]*\):.*/\1/p' $2 |
 140                 grep -i '^'"$1"'$' | head -1`
 141         if [ "$HDR" = "" ] ; then return 1 ; fi
 142         sed -n -e ':a
 143                 /^-*$/q
 144                 /^'"$HDR"':/b x
 145                 d
 146                 b a
 147                 :x
 148                 p
 149                 n
 150                 /^[     ]/b x
 151                 b a' $2
 152                 return 0
 153 }
 154
 155 ### headbody msgfile # separate msgfile into $TEMP/head $TEMP/body
 156 headbody() {
 157         sed -n '1,/^\-*$/p' "$1" > $TEMP/head
 158         sed '1,/^-*$/d' "$1" > $TEMP/body
 159 }
 160
 161 ### fixheaders -- remove Content headers, add newheaders
 162 fixheaders() {
 163         sed -n ':a
 164                 /^-*$/q
 165                 /^[Cc][Oo][Nn][Tt][Ee][Nn][Tt]-/b r
 166                 p
 167                 n
 168                 b a
 169                 :r
 170                 n
 171                 /^[     ]/b r
 172                 b a' $TEMP/head
 173         cat $TEMP/newheaders
 174         grep "^-" $TEMP/head || echo ""
 175 }
 176
 177 ### newboundary -- output a suitable boundary marker
 178 newboundary() {
 179         b=$$_`date|sed 's/[ :   ]/_/g'`
 180         for i in 0 x '=' _ + , Z 9 4 ; do
 181                 if grep "^--$b" $TEMP/body >/dev/null 2>&1 ; then
 182                         ## oops, bad boundary -- try again
 183                         b=`echo $i$b | tr \
 184 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456780=+,_' \
 185 '3Ba+c98bdACmzXpqR,tTuMDSs_hLkwZ0ef7PQrW=2x5l6E14ZKivIVgOjoJnGNUyHF'`
 186                 else
 187                         echo "$b"
 188                         return 0
 189                 fi
 190         done
 191         echo "Failed to generate unique mime boundary" >&2
 192         exit 1
 193 }
 194
 195 ### detachsign -- sign $TEMP/body, output in $TEMP/body.asc
 196 detachsign() {
 197         gpg -u "$userid" --armor --textmode --detach-sign \
 198                         <$TEMP/body >$TEMP/body.asc
 199 }
 200
 201 ### sign --- inline signature for $TEMP/body, output in $TEMP/body.asc
 202 sign() {
 203         gpg -u "$userid" --armor --textmode --clearsign \
 204                 <$TEMP/body >$TEMP/body.asc
 205 }
 206
 207 ### encrypt recipients -- encrypt $TEMP/body to recipients
 208 encrypt() {
 209         R=
 210         for i in $KL ; do
 211                 R="$R -r $i"
 212         done
 213         gpg --no-encrypt-to -u "$userid" --armor --textmode \
 214                         --always-trust --output $TEMP/body.asc \
 215                         -r "$userid" $R --sign --encrypt $TEMP/body
 216 }
 217
 218 ### Mainline processing
 219
 220 FILE="$1"       ## we assume a disk file
 221 if [ ! -r "$FILE" ] ; then
 222         echo "cannot read $FILE" >&2
 223         exit 1
 224 fi
 225
 226 case "$function" in
 227 encrypt)
 228         lookupkeys "$FILE" || exit 1
 229 esac
 230
 231 cp "$FILE" "$FILE.orig"
 232 outfile="$FILE"
 233 headbody "$FILE"
 234
 235 CT=""
 236 if grep -i "^mime-version:" $TEMP/head >/dev/null 2>&1 ; then
 237         >$TEMP/newheaders
 238         if CT=`getheader content-type $TEMP/head` ; then
 239                 echo "$CT" >$TEMP/newbody
 240                 if grep -i multipart $TEMP/newbody >/dev/null 2>&1 ; then
 241                         usemime=y  # Force MIME if already multi-part
 242                 fi
 243                 getheader content-transfer-encoding $TEMP/head \
 244                                 >>$TEMP/newbody || :
 245         else
 246                 CT=""
 247         fi
 248 else
 249         echo "Mime-Version: 1.0" >$TEMP/newheaders
 250 fi
 251
 252 if [ "$usemime" = n ] ; then
 253         ### non-MIME ###
 254         case "$function" in
 255         sign)
 256                 sign || exit 1 ;;
 257         encrypt)
 258                 encrypt || exit 1 ;;
 259         esac
 260         cat $TEMP/head $TEMP/body.asc >$outfile || exit 1
 261         exit 0
 262 fi
 263
 264 ### MIME ###
 265
 266 BDRY="`newboundary`"
 267
 268 if [ "$CT" = "" ] ; then
 269         echo "Content-Type: text/plain; charset=us-ascii" >$TEMP/newbody
 270 fi
 271 echo >>$TEMP/newbody
 272
 273 case $function in
 274 sign)
 275         sed 's/^From / &/; s/[ \r        ]*$//' $TEMP/body >>$TEMP/newbody
 276         if grep "^From " $TEMP/body >/dev/null 2>&1 ; then
 277                 echo 'Warning: "From " lines in message body have been indented' >&2
 278         fi
 279         if grep "[ \r    ]$" $TEMP/body >/dev/null 2>&1 ; then
 280                 echo 'Warning: trailing blanks removed from message body' >&2
 281         fi
 282         echo 'Content-Type: multipart/signed; protocol="application/pgp-signature";' >>$TEMP/newheaders
 283         echo "  micalg=pgp-sha1"'; boundary="'"$BDRY"'"' >>$TEMP/newheaders
 284
 285         sed -e 's/$/\r/' "$TEMP/newbody" >"$TEMP/body"
 286         detachsign || exit 1
 287         (
 288                 echo "--$BDRY"
 289                 cat $TEMP/newbody
 290                 echo
 291                 echo "--$BDRY"
 292                 echo "Content-Type: application/pgp-signature"
 293                 echo
 294                 cat $TEMP/body.asc
 295                 echo
 296                 echo "--$BDRY--"
 297                 echo
 298         ) >$TEMP/body
 299         ;;
 300
 301 encrypt)
 302         cat $TEMP/body >>$TEMP/newbody
 303         echo 'Content-Type: multipart/encrypted; protocol="application/pgp-encrypted";' >>$TEMP/newheaders
 304         echo "  boundary=\"$BDRY\"" >> $TEMP/newheaders
 305
 306         mv $TEMP/newbody $TEMP/body || exit 1
 307         encrypt || exit 1
 308         (
 309                 echo "--$BDRY"
 310                 echo "Content-Type: application/pgp-encrypted"
 311                 echo
 312                 echo "Version: 1"
 313                 echo
 314                 echo "--$BDRY"
 315                 echo "Content-Type: application/octet-stream"
 316                 echo
 317                 cat $TEMP/body.asc
 318                 echo
 319                 echo "--$BDRY--"
 320                 echo
 321         ) >"$TEMP/body"
 322         ;;
 323 esac
 324
 325 fixheaders | cat - $TEMP/body >"$outfile"