fix: is_file drift on decrypt_aes_key_with_rsa and non-str dict key coercion

self_test(is_file=False) only forwarded is_file to the public-key wrap;
decrypt_aes_key_with_rsa had no is_file parameter and always open()'d its
argument, so a PEM string was opened as a filename, misdiagnosing a good
keypair as non-pairing and leaking the private key PEM into the
FileNotFoundError traceback. decrypt_aes_key_with_rsa now takes is_file
(default True, preserving current callers), and self_test threads it
through to both key loads.

encrypt_data json.dumps a dict without checking key types, silently
stringifying int/float/bool/None keys (e.g. snowflake-int-keyed dicts),
so a decrypt round-trip silently lost the original key. encrypt_data now
raises TypeError on a non-str key instead of coercing it.

Signed-off-by: disqualifier <dev@disqualifier.me>
This commit is contained in:
2026-07-02 17:17:44 -04:00
parent 49af2a1143
commit d827dca30f
3 changed files with 61 additions and 12 deletions
+15 -3
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@@ -11,18 +11,18 @@ and storage-agnostic.
`requirements.txt`:
```
envelope_crypto @ git+ssh://git@git.rethinkstudios.io/rethink-public/envelope_crypto.git@v0.1.4
envelope_crypto @ git+ssh://git@git.rethinkstudios.io/rethink-public/envelope_crypto.git@v0.1.5
```
Direct:
```bash
pip install "envelope_crypto @ git+ssh://git@git.rethinkstudios.io/rethink-public/envelope_crypto.git@v0.1.4"
pip install "envelope_crypto @ git+ssh://git@git.rethinkstudios.io/rethink-public/envelope_crypto.git@v0.1.5"
```
Requires `cryptography` (pulled transitively).
Drop the `@v0.1.4` suffix from the line above to install the latest unpinned.
Drop the `@v0.1.5` suffix from the line above to install the latest unpinned.
## First-time setup
@@ -66,6 +66,13 @@ bot.crypto = crypto
The `keys` schema (`_id` = fingerprint, `key` = wrapped) is the **caller's** choice;
this lib only produces `(fingerprint, wrapped_key)`.
`decrypt_aes_key_with_rsa` (like `encrypt_aes_key_with_rsa` and
`get_rsa_key_fingerprint`) takes `is_file` (default `True`). Pass `is_file=False` to
hand it PEM/OpenSSH key data directly — e.g. a private key sourced from a vault —
instead of a file path. `self_test` threads the same `is_file` through to both the
public and private key it loads, so `self_test(pub_pem, priv_pem, is_file=False)`
round-trips two in-memory PEM strings rather than treating them as paths.
## Encrypt / decrypt
```python
@@ -73,6 +80,11 @@ enc = crypto.encrypt_data({"ssn": "..."}) # -> {"secure": True, "iv": ...,
plain = crypto.decrypt_data(enc) # -> {"ssn": "..."}
```
Dict keys must be `str`. `encrypt_data` raises `TypeError` on a non-str key (e.g. an
int-keyed dict of Discord snowflakes) instead of silently stringifying it — the
underlying JSON encoding has no other key type, so a coerced key would come back out
of `decrypt_data` as a `str` and no longer match the original lookup key.
For whole records: `decrypt_record(crypto, doc)` decrypts every `{secure, iv, data}`
field (nested up to `traversal_level`, default 2); `is_encrypted_record(doc)` reports
whether any encrypted field exists. Both also detect `doc` itself being a bare
+1 -1
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@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
[project]
name = "envelope_crypto"
version = "0.1.4"
version = "0.1.5"
description = "Envelope encryption (RSA-OAEP wrapped AES-256-GCM) for dict records — config-free, storage-agnostic, installable."
requires-python = ">=3.10"
dependencies = [
+44 -7
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@@ -55,6 +55,11 @@ config-free: the host supplies the DEK and RSA key paths; this lib never imports
config, configures logging, or touches a database. storage-agnostic — the
encrypted blob is a plain dict; store it in mongo, a sql json column, or a file.
encrypt_data/decrypt_data round-trip a dict only when every key is a str —
json (the wire format under the hood) has no other key type, so encrypt_data
raises TypeError on a non-str key (e.g. an int-keyed dict of discord snowflakes)
rather than silently stringifying it and losing the original key on decrypt.
naming: EnvelopeCrypto is canonical. PCICrypto / DocumentCrypto / RecordCrypto are
aliases (PCICrypto is a deprecated legacy alias). the document/record/dict
function variants are the same functions — use whichever fits your storage.
@@ -188,7 +193,11 @@ class EnvelopeCrypto:
round-trips sample data through this instance's DEK, then wraps the DEK
with the public key and unwraps with the private key, confirming they
match. run after bootstrap (or anytime as a health check) to catch a bad
keypair or wrong key path before relying on it. returns True on success.
keypair or wrong key path before relying on it. is_file (default True) is
threaded through to both the public and private key loads, so
is_file=False correctly treats both rsa_public_key and rsa_private_key as
in-memory PEM/OpenSSH data rather than opening either as a file path.
returns True on success.
"""
if not self.master_key:
raise ValueError("self_test: not initialized with a key")
@@ -199,7 +208,7 @@ class EnvelopeCrypto:
_, wrapped = self.encrypt_aes_key_with_rsa(self.master_key, rsa_public_key, is_file=is_file)
try:
recovered = self.decrypt_aes_key_with_rsa(wrapped, rsa_private_key, password=password)
recovered = self.decrypt_aes_key_with_rsa(wrapped, rsa_private_key, is_file=is_file, password=password)
except Exception as error:
raise RuntimeError(
"self_test: key unwrap failed (public/private keys do not pair, "
@@ -293,12 +302,21 @@ class EnvelopeCrypto:
return fingerprint, wrapped_b64
def decrypt_aes_key_with_rsa(
self, encrypted_key_base64: str, rsa_private_key_path: str,
password: Optional[str] = None,
self, encrypted_key_base64: str, rsa_private_key: str,
is_file: bool = True, password: Optional[str] = None,
) -> bytes:
"""unwrap an AES key with an RSA private key"""
with open(rsa_private_key_path, "rb") as key_file:
"""unwrap an AES key with an RSA private key
is_file defaults to True (rsa_private_key is a path), matching
encrypt_aes_key_with_rsa / get_rsa_key_fingerprint; pass is_file=False to
supply the PEM/OpenSSH key data directly (e.g. an in-memory or vault-sourced
key) instead of a file path.
"""
if is_file:
with open(rsa_private_key, "rb") as key_file:
key_data = key_file.read()
else:
key_data = rsa_private_key.encode() if isinstance(rsa_private_key, str) else rsa_private_key
pw = password.encode() if password else None
private_key = _load_private_key(key_data, pw)
@@ -343,13 +361,30 @@ class EnvelopeCrypto:
return new_key, wrapped
def encrypt_data(self, data: Union[Dict[str, Any], str]) -> Dict[str, str]:
"""encrypt a dict or string under the data key with a unique IV"""
"""encrypt a dict or string under the data key with a unique IV
dict keys must be str: json.dumps silently stringifies int/float/bool/None
keys (e.g. a snowflake-int-keyed dict), which would make decrypt_data return
a dict that no longer matches the original by key type or identity — a
non-str key is rejected here instead, so the failure is loud at encrypt
time rather than a silent lookup miss after decrypt.
"""
if not self.master_key:
raise ValueError("not initialized with data key")
if not isinstance(data, (dict, str)):
# a non-dict/non-str would .encode()-fail with an opaque AttributeError below;
# reject it clearly (decrypt_data only round-trips dict or str anyway)
raise TypeError(f"encrypt_data expects a dict or str, got {type(data).__name__}")
if isinstance(data, dict):
non_str_keys = [key for key in data if not isinstance(key, str)]
if non_str_keys:
# json.dumps would silently stringify these (int/float/bool/None keys),
# corrupting the round-trip (decrypt_data would return a dict keyed by
# the stringified value) — fail loud instead of coercing
raise TypeError(
"encrypt_data requires str dict keys, got non-str key(s): "
f"{[type(key).__name__ for key in non_str_keys]}"
)
data_str = json.dumps(data) if isinstance(data, dict) else data
iv = os.urandom(12)
@@ -373,6 +408,8 @@ class EnvelopeCrypto:
without a type marker it is indistinguishable from a stored dict — don't store a
bare string that is a json object if you need it back as a string. existing stored
blobs are unaffected — a dict was stored as a json object and still parses to a dict.
dict KEYS round-trip faithfully only because encrypt_data now requires str keys —
json has no other key type, so this is the only shape decrypt_data ever sees.
"""
if not self.master_key:
raise ValueError("not initialized with data key")