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