pspk

Public storage public key

Specific storage for sharing public keys of pair ECDH by curve25519.

Service provide HTTP API for save and read a 32-bytes key with human-readable name (aka. alias).

This service solve problem for persistent saving public key and send to recipient through open communication channel.

Features

• save public key with name
• load public key by name
• share some encrypted data via one-time link
• support other elliptic curve cryptography algorithms
• ephemeral encryption via API method (generate ephemeral private key on server, ecnrypt by public key and return link to data)
• signature and verification
• verification of signature by link
• QR codes
• simple cli tool (WIP)
• simple web-application. See: https://freecontent.space
• simple iOS client (thanks: l-vitaly for library for ios)
• simple android client
• local http server to pspk API
• sdk for mobile clients

Model

You should use this model:

{
	"name":"Some Name",
	"key":"base64=="
}

where:

• name - string with length more that 1000 signs
• key - encodeted to base64 32-bytes public key

Request

Save public key:

curl -X POST "https://pspk.now.sh" -d '{"name":"Some.Name","key":"E7+TL112lj1GmJRHf9jT5MZJDgYIhUbtBLc4/ZFMZ5c="}'
{"access":true,"msg":"added"}

Read public key:

curl -X POST "https://pspk.now.sh" -d '{"name":"Some.Name"}'
{"access":true,"key":"wTaZA5+QeZpby33W2T5uV8TweWaPEZn3clTe5xkmb2M="}

API

GET:

• get all keys in json array GET /?output=json-array&limit=500&last_key=&last_key=5c93d5b8149588f7c7638546 response:

[
	{"id":"5c952b5e149588f7c777c7b6","name":"x1","key":"wTaZA5+QeZpby33W2T5uV8TweWaPEZn3clTe5xkmb2M="},
	{"id":"5c952b62149588f7c777ca52","name":"x2","key":"ApYM2UsdUxFas5AF16W605950ke2iXPd5sDhg287xnM="}
]

• get data by link GET /?link=5d06a65da5cdb90006989577 response:

{"data":"123"}

• get by full name GET /?name_key=alice response

[{"id":"5c9bd58b149588f7c71bce91","name":"alice","key":"E7+TL112lj1GmJRHf9jT5MZJDgYIhUbtBLc4/ZFMZ5c="}]

• get public key in QR code by name GET /?qr_code=alice. Response will contains byes for image/png.

• get by regexp name.* GET /?name_regex=Some response

[{"id":"5c9bd58b149588f7c71bce91","name":"Some.Name","key":"E7+TL112lj1GmJRHf9jT5MZJDgYIhUbtBLc4/ZFMZ5c="},...]

POST:

• post data POST / with body {"method":"link","data":"base64=="}, response

{"link":"5d06a65da5cdb90006989577"}

• publish key POST / with body {"name":"alice","key":"base64=="}, response

{"msg":"added"}

• get key nmae POST / with body {"name":"alice"}, response

{"msg":"base64=="}

pspk cli usage

pspk - console tool which use API to pspk and implement encryption/decryption for one or several recipients.

$ pspk --help
NAME:
   pspk - pspk - encrypt you message and send through open communication channel

USAGE:
   pspk [global options] command [command options] [arguments...]

VERSION:
   0.1.2

DESCRIPTION:
   Console tool for encyption/decription data through pspk.now.sh

COMMANDS:
     publish, p                    --name <NAME> publish
     secret, s                     secret public_name
     encrypt, e                    ecnrypt pub_name some message will encrypt
     ephemeral-encrypt, ee         ee pub_name some message will encrypt
     decrypt, d                    decrypt pub_name base64==
     ephemeral-decrypt, ed         ephemeral-decryp pub_name base64==
     use-current, uc               --name name_pub_key use-current
     group, g                      --name base_name group
     start-group, sg               start-group groupName [pubName1 pubName2 ...]
     finish-group, fg              finish-group groupName pubName1 [pubName2 ...]
     secret-group, seg             secret-group groupName pubName1 [pubName2 ...]
     encrypt-group, eg             eg <GROUP_NAME> message
     ephemeral-encrypt-group, eeg  Encrypt input message with ephemeral key
     decrypt-group, dg             dg <GROUP_NAME> base64
     ephemeral-decrypt-group, edg  Decrypt input message with ephemral shared key
     sign, s                       --name <KEY_NAME> sign <MESSAGE>
	 verify, v                     verify <KEY_NAME> <SIGNATURE_IN_BASE64> <MESSAGE>
     help, h                       Shows a list of commands or help for one command

GLOBAL OPTIONS:
   --name value   key name
   --help, -h     show help
   --version, -v  print the version

Generation key pair.

Will generation private and public keys and publish public pice to pspk.now.sh.

pspk --name <NAME_YOUR_KEY> publish

Encryption some text message.

Will encryption message through your private key and public key name from pspk.now.sh.

pspk --name <NAME_YOUR_KEY> encrypt <PUBLIC_PART_NAME> <SOME_MESSAGE_WITH_SPACES>

Or encryption with ephemral key

pspk ephemeral-encrypt <PUBLIC_PART_NAME> <SOME_MESSAGE_WITH_SPACES>

Also encrypt commands have a --link boolean flag for uploading encrypted data to server. And generation link 24hrs for access data.

pspk ephemeral-encrypt --link <PUBLIC_PART_NAME> <SOME_MESSAGE_WITH_SAPCES>

Output:

base64ofencpryteddata==
https://pspk.now.sh/?link=5d07c5264f818b00069f5dda

Get data by this link return json:

{"data":"MmeSOsti98jaancR+qsbNtpL6nwPtov2p9U5diP7ahbSAhkwsYbgYMRAHMbO/gry"}

where data contains encrypted data.

Decription some text message.

Will decription message through your private key and public key name from pspk.now.sh.

pspk --name <NAME_YOUR_KEY> decrypt <PUBLIC_PART_NAME> <SOME_BASE64_WITH_SPACES>

Or decription with ephemral key

pspk --name <NAME_YOUR_KEY> ephemeral-decrypt <SOME_MESSAGE_WITH_SPACES>

Also decrypt commands have a --link <URL> string flag for downloading ecnrypted data from server.

Example:

pspk --name <NAME_YOUR_KEY> ephemeral-decrypt --link https://pspk.now.sh/?link=5d07c5264f818b00069f5dda

Group encryption exchange

For encryption/decryption need generate shared secret in group. Use this algorithm (CLIQUES) IV.A

1. Creat group. Create prime base point for group base and publish to pspk.now.sh

pspk --name base group

2. Decide number of members in group and select order for generation secret. As example Alice, Bob, Carol and Daron want creage shared secret in group base.

pspk --name alice start-group base 
pspk --name bob start-group base alice
pspk --name carol start-group base bob alice

The last members finish generate intermediate secrets.

pspk --name daron finish-group base carol bob alice

Members can start generate shared secret keys via intermediate keys.

pspk --name daron secret-group base carol bob alice
pspk --name carol secret-group base daron bob alice
pspk --name bob secret-group base daron carol alice
pspk --name alice secret-group base daron carol bob

3. Encryption Encrypt some messages for base group members

pspk --name alice ephemeral-encrypt-group base Super secret message

4. Decription Decrypt the message from member's base group

pspk --name bob ephemeral-decryp-group base base64

NOTE All intermediate secrets would saved in pspk storage!

pspk signature and verification

You can sign text message or output with pspk and you private key:

pspk --name bob sign Hello Alice!
osnfKYmhRNQx7/f3rcpA9jV0T6i/z/+XwyNFcSTGW7QKtJaBzRlbnf7Prg7Q5Hj90rfN2++CKY21IfPcIcAsAQ==

# now Alice can check signature of bob
pspk sign bob osnfKYmhRNQx7/f3rcpA9jV0T6i/z/+XwyNFcSTGW7QKtJaBzRlbnf7Prg7Q5Hj90rfN2++CKY21IfPcIcAsAQ== Hello Alice!
Signature osnfKYmhRNQx7/f3rcpA9jV0T6i/z/+XwyNFcSTGW7QKtJaBzRlbnf7Prg7Q5Hj90rfN2++CKY21IfPcIcAsAQ== is valid.

or file:

pspk --name bob sign --file ./bin/pspk
osnfKYmhRNQx7/f3rcpA9jV0T6i/z/+XwyNFcSTGW7QKtJaBzRlbnf7Prg7Q5Hj90rfN2++CKY21IfPcIcAsAQ==

# now Alice can check signature of bob
pspk sign bob osnfKYmhRNQx7/f3rcpA9jV0T6i/z/+XwyNFcSTGW7QKtJaBzRlbnf7Prg7Q5Hj90rfN2++CKY21IfPcIcAsAQ== --file ./bin/pspk
Signature osnfKYmhRNQx7/f3rcpA9jV0T6i/z/+XwyNFcSTGW7QKtJaBzRlbnf7Prg7Q5Hj90rfN2++CKY21IfPcIcAsAQ== is valid.

pspk config

pspk use $XDG_CONFIG_HOME for saving configuration or default value $HOME/.config/pspk Use config.json file for saving configuration:

{"current_name":"name"}

Also pspk use $XDG_DATA_HOME for saving appication data ro default value $HOME/.local/share/pspk