adding basic key generation script

Author: thelamer

README.md

@@ -185,6 +185,16 @@ It is also possible to run multiple copies of this container with different port
 You can volume map your own text file to `/etc/motd` to override the message displayed upon connection.  
 You can optionally set the docker argument `hostname`
 
+## Key Generation
+
+This container has a helper script to generate an ssh private/public key. In order to generate a key please run: 
+```
+docker run --rm -it --entrypoint /keygen.sh linuxserver/openssh-server
+```
+
+Then simply follow the prompts. 
+The keys generated by this script are only displayed on your console output, so make sure to save them somewhere after generation.
+
 
 
 ## Support Info
@@ -251,6 +261,7 @@ Once registered you can define the dockerfile to use with `-f Dockerfile.aarch64
 
 ## Versions
 
+* **18.01.20:** - Add key generation script.
 * **13.01.20:** - Add openssh-sftp-server.
 * **19.12.19:** - Rebasing to alpine 3.11.
 * **17.10.19:** - Initial Release.

readme-vars.yml

@@ -77,9 +77,20 @@ app_setup_block: |
   You can volume map your own text file to `/etc/motd` to override the message displayed upon connection.  
   You can optionally set the docker argument `hostname`
 
+  ## Key Generation
+  
+  This container has a helper script to generate an ssh private/public key. In order to generate a key please run: 
+  ```
+  docker run --rm -it --entrypoint /keygen.sh linuxserver/openssh-server
+  ```
+
+  Then simply follow the prompts. 
+  The keys generated by this script are only displayed on your console output, so make sure to save them somewhere after generation.
+
 
 # changelog
 changelogs:
+  - { date: "18.01.20:", desc: "Add key generation script." }
   - { date: "13.01.20:", desc: "Add openssh-sftp-server." }
   - { date: "19.12.19:", desc: "Rebasing to alpine 3.11." }
   - { date: "17.10.19:", desc: "Initial Release." }

root/keygen.sh

@@ -0,0 +1,29 @@
+#! /bin/bash
+
+# selection menu
+echo "Please select your key type to generate"
+printf "1.) ecdsa\n2.) rsa\n3.) ed25519\n4.) dsa\n[default ecdsa]:"
+read opt
+case $opt in
+  "ecdsa"|1) TYPE="ecdsa" BITS="-b 521";;
+  "rsa"|2) TYPE="rsa";;
+  "ed25519"|3) TYPE="ed25519";;
+  "dsa"|4) TYPE="dsa";;
+  *) echo "blank or unkown option choosing ecdsa" && TYPE="ecdsa" BITS="-b 521";;
+esac
+# rsa bit selection
+if [[ "$TYPE" == "rsa" ]]; then
+echo "Please select RSA bits"
+printf "1.) 4096\n2.) 2048\n3.) 1024\n[default 4096]:"
+read opt
+case $opt in
+  4096|1) BITS="-b 4096";;
+  2048|2) BITS="-b 2048";;
+  1024|3) BITS="-b 1024";;
+  *) echo "blank or unkown option choosing 4096" && BITS="-b 4096";;
+esac
+fi
+
+# key generation
+echo "YOUR KEY/PUBFILE IS BELOW PLEASE SAVE THIS DATA AS WE WILL NOT"
+echo /tmp/stderr{,.pub} | xargs -n 1 ln -sf /dev/stderr && yes | ssh-keygen -t ${TYPE} ${BITS} -N '' -qf /tmp/stderr > /dev/null