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