openssl 1.1.1 - this introduces not backward compatible changes :(

README.md

@@ -37,5 +37,12 @@ this line fetches the first public key for the github user S2- and encrypts the
 sshenc.sh -s ~/.ssh/id_rsa < encrypted.txt
 ```
 
+## Notes
+[OpenSSL 1.1.1](https://www.openssl.org/docs/man1.1.1/man1/openssl-enc.html) introduced a not backwards compatible change: the default digest to create a key from the passphrase changed from md5 to sha-256.  
+Also, a new `-iter` parameter to explicitly specify a given number of iterations on the password in deriving the encryption key was added.  
+Before OpenSSL 1.1.1 this option was not available.  
+Since the new parameters are more secure, `sshenc.sh` changed to adopt them, so since 2019-11-26, files encrypted with a previous version of `sshenc.sh` will not decrypt.  
+To do so, use the prevous `sshenc.sh` script, located at [https://sshenc.sh/sshenc-pre1.1.1.sh](https://sshenc.sh/sshenc-pre1.1.1.sh).
+
 ## License
 [MIT](https://opensource.org/licenses/MIT)

sshenc-pre1.1.1.sh

@@ -0,0 +1,109 @@
+#!/bin/bash
+
+OPTIND=1 # reset in case getopts has been used previously in the shell.
+
+me=sshenc.sh
+
+show_help() {
+cat << EOF
+usage: $me [-p <public ssh key> | -s <private ssh key>] [-h]
+
+examples:
+    - encrypt a file
+    $me -p ~/.ssh/id_rsa.pub < plain-text-file.txt > encrypted.txt
+
+    - decrypt a file
+    $me -s ~/.ssh/id_rsa < encrypted.txt
+
+$me home page: https://sshenc.sh/
+EOF
+}
+
+cleanup() {
+    rm -rf "$temp_dir"
+}
+
+while getopts "h?p:s:" opt; do
+    case "$opt" in
+    h|\?)
+    show_help
+    exit 0
+    ;;
+    p)  public_key+=("$OPTARG")
+    ;;
+    s)  private_key=$OPTARG
+    ;;
+    esac
+done
+
+shift $((OPTIND -1))
+
+[ "$1" = "--" ] && shift
+
+temp_dir="$(mktemp -d -t "$me.XXXXXX")"
+temp_file_key="$(mktemp "$temp_dir/$me.XXXXXX.key")"
+temp_file="$(mktemp "$temp_dir/$me.XXXXXX.cypher")"
+trap cleanup EXIT
+
+#encrypt
+if [[ "${#public_key[@]}" > 0 ]]; then
+    openssl rand 32 > $temp_file_key
+
+    echo "-- encrypted with https://sshenc.sh/"
+    echo "-- keys"
+    for pubkey in "${public_key[@]}"
+    do
+        if [[ -e "$pubkey" ]]; then
+            convertedpubkey=$temp_dir/$(basename "$pubkey").pem
+            ssh-keygen -f "$pubkey" -e -m PKCS8 > $convertedpubkey
+            #encrypt key with public keys
+            if openssl rsautl -encrypt -pubin -inkey "$convertedpubkey" -in "$temp_file_key" -out $temp_dir/$(basename "$pubkey").key.enc; then
+                echo "-- key"
+                openssl base64 -in $temp_dir/$(basename "$pubkey").key.enc
+                echo "-- /key"
+            fi
+        fi
+    done
+    echo "-- /keys"
+
+    if cat | openssl enc -aes-256-cbc -salt -pass file:"$temp_file_key" > "$temp_file"; then
+        openssl base64 -A < "$temp_file"
+    fi
+
+#decrypt
+elif [[ -e "$private_key" ]]; then
+    stdin=`cat`
+    keys_enc=$(echo "$stdin" | awk '/-- keys/{f=1;next} /-- \/keys/{f=0} f')
+    cypher=$(echo "$stdin" | sed -e '1,/-- \/keys/d')
+
+    i=0
+    while read line ; do \
+        if [ "$line" == "-- key" ]; then
+            i=$(($i + 1))
+        elif [ "$line" == "-- /key" ]; then
+            :
+        else
+            keys[i]="${keys[$i]}$line"
+        fi
+    done <<< "$keys_enc"
+
+    decrypted=false
+    for key in "${keys[@]}"
+    do
+        if ((echo "$key" | openssl base64 -d -A | openssl rsautl -decrypt -ssl -inkey "$private_key" > "$temp_file") > /dev/null 2>&1); then
+            if echo "$cypher" | openssl base64 -d -A | openssl aes-256-cbc -d -pass file:"$temp_file"; then
+                decrypted=true
+            fi
+        fi
+    done
+
+    if [ $decrypted = false ]; then
+        >&2 echo "no valid decryption key supplied"
+        exit 1
+    fi
+
+#help
+else
+    show_help
+    exit 1
+fi