ishencrypt

linux下的E_MAIL客户端源码

#!/bin/sh
#
# Description: signs and/or encrypt the input file and moves the pgp .asc
# output to the output file
#
ECHO=echo
DASHN="-n"

PGP=pgp

MYNAME=`basename $0`

usage()
{
   $ECHO ""
   $ECHO "Usage: $MYNAME -i infile -o outfile [-u uname] [-s] [-e -r recipient-list]"
   $ECHO "   -s   : sign"
   $ECHO "   -e   : encrypt (requires recipient-list)"
   $ECHO "  At least one of -s and -e should be present"
   $ECHO ""
   $ECHO "*** Press return to continue ***"
   read ANS
}

# defaults
USER=""
INPUT=""
OUTPUT=""
SIGN=""
ENCR=""
RECLIST=""
MIME=""
BOUNDARY=""

#
# Parse arguments
#

while test X"$1" != X
do
    case "$1" in
    -i)   INPUT=$2;
          shift 2;;
    -o)   OUTPUT=$2;
          shift 2;;
    -u)   USER=$2;
          shift 2;;
    -s)   SIGN="yes";
          shift;;
    -e)   ENCR="yes"
          shift;;
    -r)   RECLIST=$2;
          shift 2;;
    -m)   MIME="yes";
          shift;;
    -b)   BOUNDARY=$2;
          MIME="yes"
          shift 2;;
    -h)   usage;
          exit 0;;
     *)   usage;
          exit 1;;
    esac
done

#
# Check argument validity
#

# Make sure an action is selected
if test -z "$SIGN" -a -z "$ENCR"
then
    usage
    exit 1
fi

# I/O should be defined
if test -z "$INPUT" -o -z "$OUTPUT"
then
    usage
    exit 1
fi

# For encryption, recepient list must be present
if test -n "$ENCR" -a -z "$RECLIST"
then
    usage
    exit 1
fi


# Check for sign-only
if test -n "$SIGN" -a -z "$ENCR"
then
    SIGNONLY="yes"
fi


# Construct the PGP command line
ARGS="-fat"
if test -n "$USER"
then
    ARGS="${ARGS} -u '$USER'"
fi

if test -n "$SIGN"
then
    ARGS="${ARGS} -s"
fi

if test -n "$ENCR"
then
    ARGS="${ARGS} -e"
fi

# Produce detached signature for MIME messages
if test -n "$MIME" -a -n "$SIGNONLY"
then
    ARGS="${ARGS} -b"
fi

COMMAND="$PGP $ARGS $RECLIST < $INPUT >> $OUTPUT"


# Remove the output file(s)
rm -f $OUTPUT $OUTPUT.head

if test -n "$MIME"
then
    # Headers - in a separate file
    if test -n "$SIGNONLY"
    then
        $ECHO "Content-Type: multipart/signed;" >> $OUTPUT.head
        $ECHO " boundary=\"$BOUNDARY\";" >> $OUTPUT.head
        $ECHO " micalg=pgp-md5;" >> $OUTPUT.head
        $ECHO " protocol=\"application/pgp-signature\"" >> $OUTPUT.head
    else
        $ECHO "Content-Type: multipart/encrypted;" >> $OUTPUT.head
        $ECHO " boundary=\"$BOUNDARY\";" >> $OUTPUT.head
        $ECHO " protocol=\"application/pgp-encrypted\"" >> $OUTPUT.head
    fi

    # MIME boundary
    $ECHO "--$BOUNDARY" >> $OUTPUT
    
    # Output the body first if needed
    if test -n "$SIGNONLY"
    then
        cat $INPUT >> $OUTPUT
        $ECHO "" >> $OUTPUT
        $ECHO "--$BOUNDARY" >> $OUTPUT
        $ECHO "Content-Type: application/pgp-signature" >> $OUTPUT
    else
        $ECHO "Content-Type: application/pgp-encrypted" >> $OUTPUT
        $ECHO "" >> $OUTPUT
        $ECHO "--$BOUNDARY" >> $OUTPUT
        $ECHO "Content-Type: application/octet-stream" >> $OUTPUT
    fi

    # Prepare for the PGP part
    $ECHO "" >> $OUTPUT
fi

#
# Run the command and save the status
#
$ECHO "Executing $COMMAND"
eval $COMMAND
PGPSTAT=$?

if test -n "$MIME"
then
    # Final MIME boundary
    $ECHO "" >> $OUTPUT
    $ECHO "--$BOUNDARY--" >> $OUTPUT
fi

#
# Allow user to confirm
#
if test $PGPSTAT -eq 0
then
    DEFANS="Y"
else
    DEFANS="N"
fi

ANS=""

$ECHO ""
$ECHO ""

while [ "$ANS" != "y" -a "$ANS" != "Y" -a "$ANS" != "n" -a "$ANS" != "N" ]
do
   $ECHO $DASHN "Was the PGP operation successful (y/n)[$DEFANS]?"
   read ANS
   test -z "$ANS" && ANS=$DEFANS
done

if [ "$ANS" = "n" -o "$ANS" = "N" ]
then
   test $PGPSTAT -eq 0 && PGPSTAT=1
fi

exit $PGPSTAT