Table of Contents

Requirements

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Key aspects of implementation

• We implemented only 2FA (but MANY FA)
• User must authorize for 2FA (second step) only after successful login with emal+password (first step)
• We support a few kind of factors, but user have only 1 active factor at the same time 
• Now we implement only `SMS` factor type 
• We add blocking process (in case OTP error) for verifying step 
• We create additional blocking process (in case error password) for normal login process (login + password)
• Logic 2FA process based on same token_types (access_token_type && 2fa_access_token_type)
• 2FA data store at separate entity `mithril.authentication_factors` (without status model, but with logical state for 2fa & user item)
• OTP data store at existing separate entity `mithril.otp` (with status model)
• At same time we have 1 active OTP for 1 factor

Configs

2FA & OTP configurable parameters:

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• Validate token & scope
• Check login exist
  • If login exist
    • Get user by $.email
    • Validate user.password = $.password
    • If invalid -  Update user (set values) by $.user_id
      • Increment `users.priv_settings.login_error_counter` (+1)
      • If `users.priv_settings.login_error_counter` > USER_LOGIN_ERROR_MAX
        • Blocked user - update user (set values) by $.user_id
          • is_blocked = TRUE
          • block_reason = "OTP verify attempts more then USER_LOGIN_ERROR_MAX"
          • updated_at = now()
• Validate user status

• Get active 2FA item for non-blocked user by $.user_id

  Code Block
  language sql
  SELECT * FROM authentication_factors AS 2FA INNER JOIN user AS U ON 2FA.user_id = U.id WHERE U.id = $.user_id AND U.is_active = TRUE AND U.is_blocked = FALSE AND 2FA.is_active = TRUE

  • If  exist 2FA active item for user
    • go to new process with 2FA (return 2fa_access_token + code 201)
  • If not exist 2FA active item for user
    • go to standart process without 2FA (return access_token+ code 201)

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• Processed OTP lists for $.key
  • Deactivate all active OTP items (NEW → CANCELED)
• Create new OTP item
  • status = NEW
  • expired_at = now() + OTP_LIFETIME
  • value = generate number according OTP_LENGTH
  • updated_at = now()

Response

• 200 if OTP successful create & send 
• 4xx in other case

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• Validate token (2fa_access_token) - ???? 
  • If invalid - return error 4xx 
• Validate user id & user status

• Get active 2FA item for non-blocked user by $.user_id

  Code Block
  language sql
  SELECT * FROM authentication_factors AS 2FA WHERE 2FA.user_id = $.user_id AND 2FA.is_active = TRUE

  • If not found - return 409 error "Not found 2FA data for user"
• Extract type & factor from 2FA item for user
• Invoke internal function `verify OTP (key, code)`, for 2FA.type = SMS, with params:
  • key = 2FA.faсtor
  • code = $.otp
• Get result of call `verify OTP()`  
• If result = VERIFIED
  • Update user (set values) by $.user_id

    • users.priv_settings.otp_error_counter = 0

  • Update 2fa_access_token (set `tokens.details.used`=true)
  • Create & return new access_token (as a existing standart process without 2FA)
  • Return 200
• If result = UNVERIFIED
  • Update user (set values) by $.user_id
    • Increment `users.priv_settings.otp_error_counter` (+1)
  • If `users.priv_settings.otp_error_counter` > USER_OTP_ERROR_MAX
    • Blocked user - update user (set values) by $.user_id
      • is_blocked = TRUE
      • block_reason = "OTP verify attempts more then USER_OTP_ERROR_MAX"
      • updated_at = now()
  • return 401 error

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• Find 1 active OTP (status = NEW) for $.key
  • If not found - return 409 error "Not found active OTP" - ??? or 401 ?
  • If found -  increment  `attempts_count` (+1) for this OTP
    
    • If OTP.code = $.code - update OTP item:
      • OTP status  ( NEW → VERIFIED)
      • updated_at = now()
    • If (OTP.code <> $.code ) AND (OTP.attempts_count > OTP_ERROR_MAX ) 
      • Update OTP item
        • status ( NEW → UNVERIFIED)
        • updated_at = now()

Response

• 200 if OTP successful create & send 
• 4xx in other case

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