ResetPassword

1# ResetPassword.intent
2# The secure password-reset mission, end to end: a name and a goal grow into
3# guarantees, never-rules, an executable decision, and tests that prove it.
4# Compiles clean and runs 3/3 with the deterministic `intent` compiler (no AI).
5
6mission ResetPassword
7
8goal
9  Let a user securely reset their password
10
11why
12  A weak reset flow is a common path to account takeover.
13
14requires
15  verified email
16  reset token
17
18input
19  email: Email
20  token: ResetToken
21  newPassword: Secret
22
23output
24  result: PasswordResetResult
25
26constraints
27  token.ttl <= 15 minutes
28  password.minLength >= 12
29
30guarantees
31  token expires after 15 minutes
32  token can only be used once
33  password is never logged
34
35guarantee token expires after 15 minutes
36  because a long-lived reset token widens the account-takeover window
37  verify test token expiration
38
39guarantee token can only be used once
40  because a reusable reset token is an account-takeover risk
41  verify test one time use
42
43guarantee password is never logged
44  because a plaintext password in logs is a credential leak
45  verify test raw password not logged
46
47never
48  log the new password
49  return the token to the client
50
51never log the new password
52  because logs are visible to support and observability tools
53  verify test raw password not logged
54
55never return the token to the client
56  because a returned token can be replayed to seize the account
57  verify test token not returned
58
59# The reset policy is a decision, it runs, it is not a wish. `intent run` / `intent test`.
60decision CanReset
61  inputs
62    tokenAgeMinutes
63    attempts
64  rule expired
65    when tokenAgeMinutes > 15
66    return Denied
67  rule tooManyAttempts
68    when attempts >= 5
69    return Denied
70  rule allowed
71    when attempts < 5
72    return Allowed
73  default
74    return Denied
75
76target
77  DotNet
78  Tests
79
80style
81  ASP.NET Core
82  EntityFramework
83  BCrypt
84
85test CanReset
86  case fresh token
87    given tokenAgeMinutes 3, attempts 1
88    expect Allowed
89  case expired token
90    given tokenAgeMinutes 20, attempts 1
91    expect Denied
92  case locked out
93    given tokenAgeMinutes 3, attempts 5
94    expect Denied