Files
authentik/authentik/lib/avatars.py
Jens L c3445374c2 core: FIPS (#9683)
Co-authored-by: Marc 'risson' Schmitt <marc.schmitt@risson.space>
2024-05-23 17:34:52 +00:00

215 lines
7.2 KiB
Python

"""Avatar utils"""
from base64 import b64encode
from functools import cache as funccache
from hashlib import md5, sha256
from typing import TYPE_CHECKING
from urllib.parse import urlencode
from django.core.cache import cache
from django.http import HttpRequest, HttpResponseNotFound
from django.templatetags.static import static
from lxml import etree # nosec
from lxml.etree import Element, SubElement # nosec
from requests.exceptions import ConnectionError, HTTPError, RequestException, Timeout
from authentik.lib.config import get_path_from_dict
from authentik.lib.utils.http import get_http_session
from authentik.tenants.utils import get_current_tenant
if TYPE_CHECKING:
from authentik.core.models import User
GRAVATAR_URL = "https://www.gravatar.com"
DEFAULT_AVATAR = static("dist/assets/images/user_default.png")
CACHE_KEY_GRAVATAR = "goauthentik.io/lib/avatars/"
CACHE_KEY_GRAVATAR_AVAILABLE = "goauthentik.io/lib/avatars/gravatar_available"
GRAVATAR_STATUS_TTL_SECONDS = 60 * 60 * 8 # 8 Hours
SVG_XML_NS = "http://www.w3.org/2000/svg"
SVG_NS_MAP = {None: SVG_XML_NS}
# Match fonts used in web UI
SVG_FONTS = [
"'RedHatText'",
"'Overpass'",
"overpass",
"helvetica",
"arial",
"sans-serif",
]
def avatar_mode_none(user: "User", mode: str) -> str | None:
"""No avatar"""
return DEFAULT_AVATAR
def avatar_mode_attribute(user: "User", mode: str) -> str | None:
"""Avatars based on a user attribute"""
avatar = get_path_from_dict(user.attributes, mode[11:], default=None)
return avatar
def avatar_mode_gravatar(user: "User", mode: str) -> str | None:
"""Gravatar avatars"""
if not cache.get(CACHE_KEY_GRAVATAR_AVAILABLE, True):
return None
mail_hash = sha256(user.email.lower().encode("utf-8")).hexdigest() # nosec
parameters = {"size": "158", "rating": "g", "default": "404"}
gravatar_url = f"{GRAVATAR_URL}/avatar/{mail_hash}?{urlencode(parameters)}"
full_key = CACHE_KEY_GRAVATAR + mail_hash
if cache.has_key(full_key):
cache.touch(full_key)
return cache.get(full_key)
try:
# Since we specify a default of 404, do a HEAD request
# (HEAD since we don't need the body)
# so if that returns a 404, move onto the next mode
res = get_http_session().head(gravatar_url, timeout=5)
if res.status_code == HttpResponseNotFound.status_code:
cache.set(full_key, None)
return None
res.raise_for_status()
except (Timeout, ConnectionError, HTTPError):
cache.set(CACHE_KEY_GRAVATAR_AVAILABLE, False, timeout=GRAVATAR_STATUS_TTL_SECONDS)
except RequestException:
return gravatar_url
cache.set(full_key, gravatar_url)
return gravatar_url
def generate_colors(text: str) -> tuple[str, str]:
"""Generate colours based on `text`"""
color = (
int(md5(text.lower().encode("utf-8"), usedforsecurity=False).hexdigest(), 16) % 0xFFFFFF
) # nosec
# Get a (somewhat arbitrarily) reduced scope of colors
# to avoid too dark or light backgrounds
blue = min(max((color) & 0xFF, 55), 200)
green = min(max((color >> 8) & 0xFF, 55), 200)
red = min(max((color >> 16) & 0xFF, 55), 200)
bg_hex = f"{red:02x}{green:02x}{blue:02x}"
# Contrasting text color (https://stackoverflow.com/a/3943023)
text_hex = (
"000" if (red * 0.299 + green * 0.587 + blue * 0.114) > 186 else "fff" # noqa: PLR2004
)
return bg_hex, text_hex
@funccache
def generate_avatar_from_name(
name: str,
length: int = 2,
size: int = 64,
rounded: bool = False,
font_size: float = 0.4375,
bold: bool = False,
uppercase: bool = True,
) -> str:
""" "Generate an avatar with initials in SVG format.
Inspired from: https://github.com/LasseRafn/ui-avatars
"""
name_parts = name.split()
# Only abbreviate first and last name
if len(name_parts) > 2: # noqa: PLR2004
name_parts = [name_parts[0], name_parts[-1]]
if len(name_parts) == 1:
initials = name_parts[0][:length]
else:
initials = "".join([part[0] for part in name_parts[:-1]])
initials += name_parts[-1]
initials = initials[:length]
bg_hex, text_hex = generate_colors(name)
half_size = size // 2
shape = "circle" if rounded else "rect"
font_weight = "600" if bold else "400"
root_element: Element = Element(f"{{{SVG_XML_NS}}}svg", nsmap=SVG_NS_MAP)
root_element.attrib["width"] = f"{size}px"
root_element.attrib["height"] = f"{size}px"
root_element.attrib["viewBox"] = f"0 0 {size} {size}"
root_element.attrib["version"] = "1.1"
shape = SubElement(root_element, f"{{{SVG_XML_NS}}}{shape}", nsmap=SVG_NS_MAP)
shape.attrib["fill"] = f"#{bg_hex}"
shape.attrib["cx"] = f"{half_size}"
shape.attrib["cy"] = f"{half_size}"
shape.attrib["width"] = f"{size}"
shape.attrib["height"] = f"{size}"
shape.attrib["r"] = f"{half_size}"
text = SubElement(root_element, f"{{{SVG_XML_NS}}}text", nsmap=SVG_NS_MAP)
text.attrib["x"] = "50%"
text.attrib["y"] = "50%"
text.attrib["style"] = (
f"color: #{text_hex}; " "line-height: 1; " f"font-family: {','.join(SVG_FONTS)}; "
)
text.attrib["fill"] = f"#{text_hex}"
text.attrib["alignment-baseline"] = "middle"
text.attrib["dominant-baseline"] = "middle"
text.attrib["text-anchor"] = "middle"
text.attrib["font-size"] = f"{round(size * font_size)}"
text.attrib["font-weight"] = f"{font_weight}"
text.attrib["dy"] = ".1em"
text.text = initials if not uppercase else initials.upper()
return etree.tostring(root_element).decode()
def avatar_mode_generated(user: "User", mode: str) -> str | None:
"""Wrapper that converts generated avatar to base64 svg"""
# By default generate based off of user's display name
name = user.name.strip()
if name == "":
# Fallback to username
name = user.username.strip()
# If we still don't have anything, fallback to `a k`
if name == "":
name = "a k"
svg = generate_avatar_from_name(name)
return f"data:image/svg+xml;base64,{b64encode(svg.encode('utf-8')).decode('utf-8')}"
def avatar_mode_url(user: "User", mode: str) -> str | None:
"""Format url"""
mail_hash = md5(user.email.lower().encode("utf-8"), usedforsecurity=False).hexdigest() # nosec
return mode % {
"username": user.username,
"mail_hash": mail_hash,
"upn": user.attributes.get("upn", ""),
}
def get_avatar(user: "User", request: HttpRequest | None = None) -> str:
"""Get avatar with configured mode"""
mode_map = {
"none": avatar_mode_none,
"initials": avatar_mode_generated,
"gravatar": avatar_mode_gravatar,
}
tenant = None
if request:
tenant = request.tenant
else:
tenant = get_current_tenant()
modes: str = tenant.avatars
for mode in modes.split(","):
avatar = None
if mode in mode_map:
avatar = mode_map[mode](user, mode)
elif mode.startswith("attributes."):
avatar = avatar_mode_attribute(user, mode)
elif "://" in mode:
avatar = avatar_mode_url(user, mode)
if avatar:
return avatar
return avatar_mode_none(user, modes)