diff --git a/emailflow.md b/emailflow.md index 52689f0..bec0129 100644 --- a/emailflow.md +++ b/emailflow.md @@ -3,21 +3,28 @@ In creating an email flow that maintains PRIVACY and SECURITY whilst also being convenient to use, the following principles were observed: - Keypair must be generated client-side -- Keypair must be protected by a password -- There must be protection from keyloggers +- Keypair must be protected by a long and complex password - It must be possible to change the password - It must remain possible to work offline - Network traffic must not contain identifying metadata -All of the above is achieved using a high level flow as follows: +All of the above is achieved using a high level signup flow as follows: -1. Generate temporary key pair for secure server communication -2. Validate email using a 6 digit code -3. Provide some server side entropy to client -4. Combine entropy + complex user password to encrypt the final keypair -5. Store the encrypted keypair on the server +1. User provides email and complex password +2. These are used to encrypt a locally generated keypair into a backup +3. Email address, Public Key and encrypted backup are sent to the server +4. Account is validated -The password is only used to encrypt the key and is never stored or sent anywhere. Hence, the server cannot decrypt the backup. All key signing / encryption operations happen on client side using [private class properties](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes/Private_properties). +The password is only used to encrypt/decrypt the local backup and is never stored or sent anywhere. + +When perforing a login, the flow is: + +1. Generate a temporary key pair for secure server communication +2. Validate the email +3. Provide the encrypted keypair for the user to unlock + + +All key signing / encryption operations happen on client side using [private class properties](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes/Private_properties). ## SIGNUP FLOW @@ -27,47 +34,44 @@ sequenceDiagram autoNumber actor U as SIGit User participant W as SIGit Website - participant D as DVM - Participant DB as DataBase - Note over W,D: All comms over
Nostr Relay - U->>W: Click SIGNUP and enter
email address - Note over W: Ephemeral key generated
to communicate with DVM - W->>D: Request Account - Note right of W: Event uses PoW and
encrypts only EMAIL
to dvm@sigit.io pubkey - D -x DB: Verify PoW and check
if email exists - Note over D: If email already exists,
send user to LOGIN.
Otherwise#58; - D->>DB: Create Temp Session - Note over DB: SESSION entry#58;
#128274;session.pubkey="ephemeral pubkey"
session.email=lowcase($EMAIL)
session.email_code=INT (6 digits)
session.created_at=now() + participant D as Server + Participant DB + Note over W,D: All comms encrypted with throwaway
(ephemeral) client keys and a
.well-known server key + U->>W: Click SIGNUP + U->>W: Provide Email and Complex Password + Note over W: Validate Email
Ensure Complex Password + + Note right of U: User is warned that they CANNOT
RESET PASSWORD, should USE
PASSWORD MANAGER etc + + + Note over W: Nostr Keypair Generated
& Encrypted inside a
PRIVATE method,
with COMPLEX password.
Password variable is not
stored, sent or printed
anywhere.
Any sensitive variables
are immediately destroyed. + W->>D: Request account activation + Note right of W: Event uses PoW and
encrypts PUBKEY, EMAIL,
and the encrypted BACKUP
to the dvm@sigit.io pubkey
using the ephemeral key + Note over D: Verify PoW,
event.created_at,
event.id + D -x DB: Check if email exists + Note over D: If email already exists, and
user.last_seen <> null then
send user to LOGIN.

If email exists and last_seen
is null, then DELETE the
current entry.

Otherwise#58; + D->>DB: Create DB entries + Note over DB: USER insert#58;
#128274;user.id=uid()
user.pubkey=lowcase($PUBKEY)
user.email=lowcase($EMAIL)
user.last_seen=null
user.created_at=now()
user.bkp=$BACKUP + Note over DB: SESSION insert#58;
#128274;session.pubkey="ephemeral pubkey"
session.email_code=INT (6 digits)
session.user_id=user.id
session.created_at=now() D->>U: Send session.email_code via email D->>W: Account created - Note left of D: Payload is an empty string or
an encrypted (and detailed)
error message + Note left of D: Payload is the user.id and/or
an encrypted (and detailed)
error message + Note over W: Verify DVM pubkey,
event.created_at,
event.id W->>U: Tell user to check email and
to open it in the
SAME BROWSER SESSION Note over W: Screen to accept the 6 digits
is already displayed
(mobile optimised if relevant) U->>W: User opens link or enters the code W->>D: Verify Account - Note right of W: Event uses PoW and
encrypts only CODE
to DVM pubkey + Note right of W: Event uses PoW and
encrypts both user_id
and email_code
to DVM pubkey D -x DB: Check email_code where
session pk=event pk - D->>DB: If code matches,
create User Account - Note over DB: USER entry#58;
#128274;user.id=uid()
user.email=session.email
user.pubkey=""
user.activated=false
user.created_at=now()
user.bkp=""
user.entropy=uid() - D->>W: Provide user.entropy - Note left of D: Payload encrypted to ephemeral
pubkey. Is either a UID or a
detailed error message. - Note over W: Client verifies that
DVM response came from
DVM pubkey - W->>U: Ask for secure password - Note right of U: This password is what prevents
backend from decrypting the nsec - Note right of U: User is warned that they CANNOT
RESET PASSWORD, should USE
PASSWORD MANAGER etc - U->>W: Enter password (twice) + D->>DB: If email_code matches,
update USER table where
session.user_id=user.id - Note over W: Nostr Keypair Generated
& Encrypted inside a
PRIVATE METHOD,
using password + entropy.
Password variable is not
stored, sent or printed
anywhere. Temporary
variables are destroyed. - W->>D: Request account activation - Note right of W: Event uses PoW and
encrypts both PUBKEY
and the already-
encrypted BACKUP
to the DVM pubkey - D -x DB: Ensure event pubkey
in SESSION table - D->>DB: Update Account - Note over DB: user.activated=true
user.pubkey=$pubkey
user.bkp=$backup + Note over DB: USER update#58;
user.last_seen=now() D->>W: Account activated Note left of D: Payload is an empty string or
an encrypted (and detailed)
error message + Note over W: Verify DVM pubkey,
event.created_at,
event.id W->>U: User is automatically logged in - Note over W: Ephemeral key is destroyed
Default relay list applied + Note over W: Ephemeral key is destroyed
Default relay list is broadcast
using the user pubkey ```