From d8a4eba872fbba7d1a45edd20c9450703015613c Mon Sep 17 00:00:00 2001
From: Frank Bischof <info@meer-web.nl>
Date: Fri, 23 Feb 2024 08:25:16 +0000
Subject: [PATCH] #1 - Adding filehash

---
 README.md  |  6 ++++--
 crypter.sh | 38 ++++++++++++++++++++++++++------------
 2 files changed, 30 insertions(+), 14 deletions(-)

diff --git a/README.md b/README.md
index 27dadd7..9f08140 100644
--- a/README.md
+++ b/README.md
@@ -6,5 +6,7 @@ Script to encrypt and decrypt files easily using openssl
     -e for encrypt
     -d for decrypt
 ## Additional info
-Uses des-ede3-cbc pbkdf2 with salt by default but can be configured in the ~/.crypter/.keys file.\
-Files are converted using base64 encoding.
+Uses des-ede3-cbc pbkdf2 with salt by default but can be configured in the ~/.crypter/.algos file.\
+Files are converted using base64 encoding.\
+
+Files hash is checked uppon decrypting
diff --git a/crypter.sh b/crypter.sh
index f9d9614..a93d455 100755
--- a/crypter.sh
+++ b/crypter.sh
@@ -16,20 +16,21 @@ else
 	exit 1
 fi
 
-# Check if keys are set
-if [ ! -f ~/.crypter/.keys ]
+# Check if algos are set
+if [ ! -f ~/.crypter/.algos ]
 then
 	mkdir -p ~/.crypter
-	echo "KEYS=\"-des-ede3-cbc -pbkdf2\"" > ~/.crypter/.keys
+	echo "ALGOS=\"-des-ede3-cbc -pbkdf2\"" > ~/.crypter/.algos
 fi
-source ~/.crypter/.keys
+source ~/.crypter/.algos
 
 # Check method
 case "$1" in 
 	"-e")
 		echo "Encrypting file ${INPUT}"
-		OUTPUT="${INPUT}.crypto"
-		openssl enc $KEYS -salt -in ${INPUT} -out ${OUTPUT}.temp
+		HASH=$(sha256sum $INPUT | awk '{ print $1 }')
+		OUTPUT="${INPUT}.${HASH}.crypto"
+		openssl enc $ALGOS -salt -in ${INPUT} -out ${OUTPUT}.temp
 		base64 ${OUTPUT}.temp > ${OUTPUT}
 		rm -f ${OUTPUT}.temp
 		if [ "`stat ${OUTPUT} | grep Size | awk '{ print $2}'`" != 0 ]
@@ -47,18 +48,31 @@ case "$1" in
 		;;
 	"-d")
 		echo "Decrypting file ${INPUT}";
-		OUTPUT="`echo $INPUT | sed 's/\.crypto//'`" #Tim of the last extension in future update"
+		OUTPUT=$(echo $INPUT | sed 's/\.crypto//')
+		HASH=$(echo $OUTPUT | sed 's/^.*\.//')
 		base64 -d ${INPUT} > ${INPUT}.temp
-		openssl enc -d $KEYS -in ${INPUT}.temp -out ${OUTPUT}
+		openssl enc -d $ALGOS -in ${INPUT}.temp -out ${OUTPUT}
 		rm -f ${INPUT}.temp
 		if [ "`stat ${OUTPUT} | grep Size | awk '{ print $2}'`" != 0 ]
 		then
-			# OK - safe to delete the original input file
-			echo "OK - Deleting file ${INPUT}"
-			rm -f ${INPUT}
+			# SHA256SUM CHECK
+			CUR_HASH=$(sha256sum ${OUTPUT} | awk '{ print $1 }')
+			if [ "${HASH}" != "${CUR_HASH}" ]
+			then
+				# NOK - Hash mismatch
+				echo "CRITICAL - Hashes mismatching!"
+				rm -f ${OUTPUT}
+				exit 2
+			else
+				# OK - safe to delete the original input file
+				echo "OK - Hashes matching, deleting input file"
+				rm -f ${INPUT}
+				mv ${OUTPUT} $(echo $OUTPUT | sed 's/\..*//')
+				exit 0
+			fi
 		else
 			# NOK - remove empty output file
-			echo "CRITICAL - Output file ${OUTPUT} is 0 bytes! Not removing the source file ${INPUT}"
+			echo "CRITICAL - Output file is 0 bytes! Not removing the input file"
 			rm -f ${OUTPUT}
 			exit 2
 		fi