extracted from knoppix-autoconfig:

<<START>>

# Try to mount this filesystem read-only, without or with encryption
# trymount device|file mountpoint
trymount(){
# Check if already mounted
case "$(cat /proc/mounts)" in *\ $2\ *) return 0;; esac
# Create target directory if it doesn't exist yet
[ -d "$2" ] || mkdir -p "$2"
RC=""
# Apparently, mount-aes DOES autodetect AES loopback files.
[ -b "$1" ] && { mount -t auto -o ro "$1" "$2" 2>/dev/null; RC="$?"; }
# We need to mount crypto-loop files with initial rw support
[ -f "$1" ] && { mount -t auto -o loop,rw "$1" "$2" 2>/dev/null; RC="$?"; }
# Mount succeeded?
[ "$RC" = "0" ] && return 0
echo ""
echo "${CYAN}Filesystem not autodetected, trying to mount $1 with AES256 encryption${NORMAL}"
sleep 2
a="y"
while [ "$a" != "n" -a "$a" != "N" ]; do
# We need to mount crypto-loop files with initial rw support
PW="$(dialog --title "Encrypted Partition?" --stdout --insecure --passwordbox "Please enter decryption password:" 8 40)"
[ "$?" != "0" ] && break
mount -p0 -t auto -o loop,rw,encryption=AES256 "$1" "$2" <<EOT
$PW
EOT
[ "$?" = "0" ] && { unset PW; return 0; }
unset PW
echo -n "${RED}Mount failed, retry? [Y/n] ${NORMAL}"
read a
done
return 1
}

<<END>>

<<START>>

# Try to mount this filesystem read-only, without or with encryption
# trymount device|file mountpoint
trymount(){
# Check if already mounted
case "$(cat /proc/mounts)" in *\ $2\ *) return 0;; esac
# Create target directory if it doesn't exist yet
[ -d "$2" ] || mkdir -p "$2"
RC=""
# Apparently, mount-aes DOES autodetect AES loopback files.
[ -b "$1" ] && { mount -t auto -o ro "$1" "$2" 2>/dev/null; RC="$?"; }
# We need to mount crypto-loop files with initial rw support
[ -f "$1" ] && { mount -t auto -o loop,rw "$1" "$2" 2>/dev/null; RC="$?"; }
# Mount succeeded?
[ "$RC" = "0" ] && return 0
echo ""
echo "${CYAN}Filesystem not autodetected, trying to mount $1 with AES256 encryption${NORMAL}"
sleep 2
a="y"
while [ "$a" != "n" -a "$a" != "N" ]; do
# We need to mount crypto-loop files with initial rw support
PW="$(dialog --title "Encrypted Partition?" --stdout --insecure --passwordbox "Please enter decryption password:" 8 40)"
[ "$?" != "0" ] && break
mount -p0 -t auto -o loop,rw,encryption=AES256 "$1" "$2" <<EOT
$PW
EOT
[ "$?" = "0" ] && { unset PW; return 0; }
unset PW
echo -n "${RED}Mount failed, retry? [Y/n] ${NORMAL}"
read a
done
return 1
}

<<END>>

<<START>>

# Try to mount this filesystem read-only, without or with encryption
# trymount device|file mountpoint
trymount(){
# Check if already mounted
case "$(cat /proc/mounts)" in *\ $2\ *) return 0;; esac
# Create target directory if it doesn't exist yet
[ -d "$2" ] || mkdir -p "$2"
RC=""
# Apparently, mount-aes DOES autodetect AES loopback files.
[ -b "$1" ] && { mount -t auto -o ro "$1" "$2" 2>/dev/null; RC="$?"; }
# We need to mount crypto-loop files with initial rw support
[ -f "$1" ] && { mount -t auto -o loop,rw "$1" "$2" 2>/dev/null; RC="$?"; }
# Mount succeeded?
[ "$RC" = "0" ] && return 0
echo ""
echo "${CYAN}Filesystem not autodetected, trying to mount $1 with AES256 encryption${NORMAL}"
sleep 2
a="y"
while [ "$a" != "n" -a "$a" != "N" ]; do
# We need to mount crypto-loop files with initial rw support
PW="$(dialog --title "Encrypted Partition?" --stdout --insecure --passwordbox "Please enter decryption password:" 8 40)"
[ "$?" != "0" ] && break
mount -p0 -t auto -o loop,rw,encryption=AES256 "$1" "$2" <<EOT
$PW
EOT
[ "$?" = "0" ] && { unset PW; return 0; }
unset PW
echo -n "${RED}Mount failed, retry? [Y/n] ${NORMAL}"
read a
done
return 1
}

<<END>>