1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
|
from datetime import datetime, timedelta, timezone
import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
OAuth2PasswordBearer,
OAuth2PasswordRequestForm,
SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError
# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30
fake_users_db = {
"johndoe": {
"username": "johndoe",
"full_name": "John Doe",
"email": "johndoe@example.com",
"hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
"disabled": False,
},
"alice": {
"username": "alice",
"full_name": "Alice Chains",
"email": "alicechains@example.com",
"hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
"disabled": True,
},
}
class Token(BaseModel):
access_token: str
token_type: str
class TokenData(BaseModel):
username: str | None = None
scopes: list[str] = []
class User(BaseModel):
username: str
email: str | None = None
full_name: str | None = None
disabled: bool | None = None
class UserInDB(User):
hashed_password: str
password_hash = PasswordHash.recommended()
oauth2_scheme = OAuth2PasswordBearer(
tokenUrl="token",
scopes={"me": "Read information about the current user.", "items": "Read items."},
)
app = FastAPI()
def verify_password(plain_password, hashed_password):
return password_hash.verify(plain_password, hashed_password)
def get_password_hash(password):
return password_hash.hash(password)
def get_user(db, username: str):
if username in db:
user_dict = db[username]
return UserInDB(**user_dict)
def authenticate_user(fake_db, username: str, password: str):
user = get_user(fake_db, username)
if not user:
return False
if not verify_password(password, user.hashed_password):
return False
return user
def create_access_token(data: dict, expires_delta: timedelta | None = None):
to_encode = data.copy()
if expires_delta:
expire = datetime.now(timezone.utc) + expires_delta
else:
expire = datetime.now(timezone.utc) + timedelta(minutes=15)
to_encode.update({"exp": expire})
encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
return encoded_jwt
async def get_current_user(
security_scopes: SecurityScopes, token: str = Depends(oauth2_scheme)
):
if security_scopes.scopes:
authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
else:
authenticate_value = "Bearer"
credentials_exception = HTTPException(
status_code=status.HTTP_401_UNAUTHORIZED,
detail="Could not validate credentials",
headers={"WWW-Authenticate": authenticate_value},
)
try:
payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
username: str = payload.get("sub")
if username is None:
raise credentials_exception
scope: str = payload.get("scope", "")
token_scopes = scope.split(" ")
token_data = TokenData(scopes=token_scopes, username=username)
except (InvalidTokenError, ValidationError):
raise credentials_exception
user = get_user(fake_users_db, username=token_data.username)
if user is None:
raise credentials_exception
for scope in security_scopes.scopes:
if scope not in token_data.scopes:
raise HTTPException(
status_code=status.HTTP_401_UNAUTHORIZED,
detail="Not enough permissions",
headers={"WWW-Authenticate": authenticate_value},
)
return user
async def get_current_active_user(
current_user: User = Security(get_current_user, scopes=["me"]),
):
if current_user.disabled:
raise HTTPException(status_code=400, detail="Inactive user")
return current_user
@app.post("/token")
async def login_for_access_token(
form_data: OAuth2PasswordRequestForm = Depends(),
) -> Token:
user = authenticate_user(fake_users_db, form_data.username, form_data.password)
if not user:
raise HTTPException(status_code=400, detail="Incorrect username or password")
access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
access_token = create_access_token(
data={"sub": user.username, "scope": " ".join(form_data.scopes)},
expires_delta=access_token_expires,
)
return Token(access_token=access_token, token_type="bearer")
@app.get("/users/me/", response_model=User)
async def read_users_me(current_user: User = Depends(get_current_active_user)):
return current_user
@app.get("/users/me/items/")
async def read_own_items(
current_user: User = Security(get_current_active_user, scopes=["items"]),
):
return [{"item_id": "Foo", "owner": current_user.username}]
@app.get("/status/")
async def read_system_status(current_user: User = Depends(get_current_user)):
return {"status": "ok"}
|
