fix: section Securite du compte incomplete BUG-068 (boutons theme, QR local, mot de passe, recovery WebAuthn)

backend/auth/router.py

@@ -448,7 +448,9 @@ class MfaEnableRequest(BaseModel):
 async def mfa_totp_setup(current_user=Depends(require_auth)):
     """Generate a TOTP secret and QR URI for MFA setup.
 
-    Returns the secret and otpauth URI — client displays QR code.
+    Returns the secret, the otpauth URI and a ready-to-display QR code
+    (`qr_data_url`, SVG `data:` URI — no third-party service, CSP-safe).
+
     Does NOT enable MFA yet; call /mfa/totp/enable after first successful verify.
     """
     from .user_store import update_user
@@ -458,10 +460,21 @@ async def mfa_totp_setup(current_user=Depends(require_auth)):
     update_user(current_user["username"], {
         "mfa_secret_pending": secret,
     })
+    # BUG-068: the QR code is generated locally (segno, stdlib-free SVG data
+    # URI). The previous client-side https://api.qrserver.com image was blocked
+    # by the CSP (img-src 'self' data: blob:) and leaked the otpauth URI —
+    # including the TOTP secret — to a third party.
+    qr_data_url: str | None = None
+    try:
+        import segno
+        qr_data_url = segno.make(qr_uri).svg_data_uri(scale=5)
+    except Exception:
+        qr_data_url = None
     return {
         "secret": secret,
         "qr_uri": qr_uri,
         "otpauth_uri": qr_uri,
+        "qr_data_url": qr_data_url,
     }
 
 

backend/requirements.txt

@@ -15,6 +15,7 @@ weasyprint>=60.0
 httpx>=0.27.0
 pypdf>=4.0
 pyotp>=2.10.0
+segno>=1.5.0
 webauthn==2.6.0
 psutil>=5.9
 pywebpush>=2.3.0