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