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         whom -ali -tocc -nobcc "$1" | while read i ; do
 113                 case "$i" in
 114                 '|'*)   echo "Ignoring pipe address" >&2
 115                         continue ;;
 116                 *@*)    ;;
 117                 *)      i="$i@`hostname -f`" ;;
 118                 esac
 119                 # extract the actual address
 120                 format='%<{error}%{error}: %{text}%|%(addr{text})%>'
 121                 i=`%libdir%/ap -form "=$format" "$i"`
 122                 if k=`lookupkeyfile "$i"` ; then
 123                         KL="$KL $k"
 124                 elif k=`lookupkeyring "$i"` ; then
 125                         KL="$KL $k"
 126                 else
 127                         echo "Could not find key for <$i>" >&2
 128                         status=1
 129                 fi
 130         done
 131         return $status
 132 }
 133
 134 ### getheader headername msgfile
 135 getheader() {
 136         HDR=`sed -n -e '/^-*$/q' -e 's/^\([^    :]*\):.*/\1/p' $2 |
 137                 grep -i '^'"$1"'$' | head -1`
 138         if [ "$HDR" = "" ] ; then return 1 ; fi
 139         sed -n -e ':a
 140                 /^-*$/q
 141                 /^'"$HDR"':/b x
 142                 d
 143                 b a
 144                 :x
 145                 p
 146                 n
 147                 /^[     ]/b x
 148                 b a' $2
 149                 return 0
 150 }
 151
 152 ### headbody msgfile # separate msgfile into $TEMP/head $TEMP/body
 153 headbody() {
 154         sed -n '1,/^\-*$/p' "$1" > $TEMP/head
 155         sed '1,/^-*$/d' "$1" > $TEMP/body
 156 }
 157
 158 ### fixheaders -- remove Content headers, add newheaders
 159 fixheaders() {
 160         sed -n ':a
 161                 /^-*$/q
 162                 /^[Cc][Oo][Nn][Tt][Ee][Nn][Tt]-/b r
 163                 p
 164                 n
 165                 b a
 166                 :r
 167                 n
 168                 /^[     ]/b r
 169                 b a' $TEMP/head
 170         cat $TEMP/newheaders
 171         grep "^-" $TEMP/head || echo ""
 172 }
 173
 174 ### newboundary -- output a suitable boundary marker
 175 newboundary() {
 176         b=$$_`date|sed 's/[ :   ]/_/g'`
 177         for i in 0 x '=' _ + , Z 9 4 ; do
 178                 if grep "^--$b" $TEMP/body >/dev/null 2>&1 ; then
 179                         ## oops, bad boundary -- try again
 180                         b=`echo $i$b | tr \
 181 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456780=+,_' \
 182 '3Ba+c98bdACmzXpqR,tTuMDSs_hLkwZ0ef7PQrW=2x5l6E14ZKivIVgOjoJnGNUyHF'`
 183                 else
 184                         echo "$b"
 185                         return 0
 186                 fi
 187         done
 188         echo "Failed to generate unique mime boundary" >&2
 189         exit 1
 190 }
 191
 192 ### detachsign -- sign $TEMP/body, output in $TEMP/body.asc
 193 detachsign() {
 194         gpg -u "$userid" --armor --textmode --detach-sign \
 195                         <$TEMP/body >$TEMP/body.asc
 196 }
 197
 198 ### sign --- inline signature for $TEMP/body, output in $TEMP/body.asc
 199 sign() {
 200         gpg -u "$userid" --armor --textmode --clearsign \
 201                 <$TEMP/body >$TEMP/body.asc
 202 }
 203
 204 ### encrypt recipients -- encrypt $TEMP/body to recipients
 205 encrypt() {
 206         R=
 207         for i in $KL ; do
 208                 R="$R -r $i"
 209         done
 210         gpg --no-encrypt-to -u "$userid" --armor --textmode \
 211                         --always-trust --output $TEMP/body.asc \
 212                         -r "$userid" $R --sign --encrypt $TEMP/body
 213 }
 214
 215 ### Mainline processing
 216
 217 FILE="$1"       ## we assume a disk file
 218 if [ ! -r "$FILE" ] ; then
 219         echo "cannot read $FILE" >&2
 220         exit 1
 221 fi
 222
 223 case "$function" in
 224 encrypt)
 225         lookupkeys "$FILE" || exit 1
 226 esac
 227
 228 cp "$FILE" "$FILE.orig"
 229 outfile="$FILE"
 230 headbody "$FILE"
 231
 232 CT=""
 233 if grep -i "^mime-version:" $TEMP/head >/dev/null 2>&1 ; then
 234         >$TEMP/newheaders
 235         if CT=`getheader content-type $TEMP/head` ; then
 236                 echo "$CT" >$TEMP/newbody
 237                 if grep -i multipart $TEMP/newbody >/dev/null 2>&1 ; then
 238                         usemime=y  # Force MIME if already multi-part
 239                 fi
 240                 getheader content-transfer-encoding $TEMP/head \
 241                                 >>$TEMP/newbody || :
 242         else
 243                 CT=""
 244         fi
 245 else
 246         echo "Mime-Version: 1.0" >$TEMP/newheaders
 247 fi
 248
 249 if [ "$usemime" = n ] ; then
 250         ### non-MIME ###
 251         case "$function" in
 252         sign)
 253                 sign || exit 1 ;;
 254         encrypt)
 255                 encrypt || exit 1 ;;
 256         esac
 257         cat $TEMP/head $TEMP/body.asc >$outfile || exit 1
 258         exit 0
 259 fi
 260
 261 ### MIME ###
 262
 263 BDRY="`newboundary`"
 264
 265 if [ "$CT" = "" ] ; then
 266         echo "Content-Type: text/plain; charset=us-ascii" >$TEMP/newbody
 267 fi
 268 echo >>$TEMP/newbody
 269
 270 case $function in
 271 sign)
 272         sed 's/^From / &/; s/[ \r        ]*$//' $TEMP/body >>$TEMP/newbody
 273         if grep "^From " $TEMP/body >/dev/null 2>&1 ; then
 274                 echo 'Warning: "From " lines in message body have been indented' >&2
 275         fi
 276         if grep "[ \r    ]$" $TEMP/body >/dev/null 2>&1 ; then
 277                 echo 'Warning: trailing blanks removed from message body' >&2
 278         fi
 279         echo 'Content-Type: multipart/signed; protocol="application/pgp-signature";' >>$TEMP/newheaders
 280         echo "  micalg=pgp-sha1"'; boundary="'"$BDRY"'"' >>$TEMP/newheaders
 281
 282         sed -e 's/$/\r/' "$TEMP/newbody" >"$TEMP/body"
 283         detachsign || exit 1
 284         (
 285                 echo "--$BDRY"
 286                 cat $TEMP/newbody
 287                 echo
 288                 echo "--$BDRY"
 289                 echo "Content-Type: application/pgp-signature"
 290                 echo
 291                 cat $TEMP/body.asc
 292                 echo
 293                 echo "--$BDRY--"
 294                 echo
 295         ) >$TEMP/body
 296         ;;
 297
 298 encrypt)
 299         cat $TEMP/body >>$TEMP/newbody
 300         echo 'Content-Type: multipart/encrypted; protocol="application/pgp-encrypted";' >>$TEMP/newheaders
 301         echo "  boundary=\"$BDRY\"" >> $TEMP/newheaders
 302
 303         mv $TEMP/newbody $TEMP/body || exit 1
 304         encrypt || exit 1
 305         (
 306                 echo "--$BDRY"
 307                 echo "Content-Type: application/pgp-encrypted"
 308                 echo
 309                 echo "Version: 1"
 310                 echo
 311                 echo "--$BDRY"
 312                 echo "Content-Type: application/octet-stream"
 313                 echo
 314                 cat $TEMP/body.asc
 315                 echo
 316                 echo "--$BDRY--"
 317                 echo
 318         ) >"$TEMP/body"
 319         ;;
 320 esac
 321
 322 fixheaders | cat - $TEMP/body >"$outfile"