2 Commits
Author SHA1 Message Date
dsql d827dca30f 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>
2026-07-02 17:17:44 -04:00
dsql 49af2a1143 fix: reencrypt/is_encrypted_record/decrypt_record miss self-blob and deep-nested records
Two silent-data-loss paths in the record-level functions: (1) reencrypt's
traversal_level cutoff silently left blobs nested deeper than the default
under the old key with no signal, contradicting its own documented fail-loud
rotation contract, and is_encrypted_record shared the cutoff so a
post-rotation audit couldn't detect the leftover; (2) all three record
functions inspected only record.values(), never the record itself, so a bare
{secure, iv, data} blob used as the whole document (the README's file-storage
pattern) was invisible to is_encrypted_record and passed through reencrypt
unchanged under the old key.

reencrypt now raises when a blob sits deeper than traversal_level instead of
silently truncating, and detects/handles the record-itself-is-a-blob case;
is_encrypted_record falls back to an unbounded-depth scan past
traversal_level so it reliably flags leftovers regardless of nesting depth;
decrypt_record likewise handles a record that is itself a blob. Bumped to
v0.1.4.

Signed-off-by: disqualifier <dev@disqualifier.me>
2026-07-02 16:40:37 -04:00
3 changed files with 160 additions and 30 deletions
+31 -5
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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@v0.1.3
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@v0.1.3"
pip install "envelope_crypto @ git+ssh://git@git.rethinkstudios.io/rethink-public/envelope_crypto.git@v0.1.5"
```
Requires `cryptography` (pulled transitively).
Drop the `@v0.1.3` 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
@@ -73,9 +80,16 @@ 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.
whether any encrypted field exists. Both also detect `doc` itself being a bare
`{secure, iv, data}` blob (the file-storage pattern below, where the blob IS the whole
document) — not just blobs nested under a key.
```python
from envelope_crypto import is_encrypted_record, decrypt_record
@@ -84,6 +98,11 @@ if is_encrypted_record(doc):
doc = decrypt_record(crypto, doc)
```
`is_encrypted_record` falls back to an unbounded-depth scan once `traversal_level` is
exhausted, so it reliably reports `True` for a blob left behind by a shallower
`decrypt_record`/`reencrypt` call — safe to use as a leftover-detecting audit after
rotation, regardless of how deep the blob is nested.
Naming aliases (same objects): `EnvelopeCrypto` = `DocumentCrypto` = `RecordCrypto`
= `PCICrypto` (deprecated legacy alias). `decrypt_record` = `decrypt_document` =
`decrypt_dict`; `is_encrypted_record` = `is_encrypted_document` = `is_encrypted_dict`.
@@ -129,7 +148,14 @@ for fingerprint, wrapped_key in wrapped.items():
`reencrypt(source_crypto, record)` is a method on the **destination** (new-key)
instance: it decrypts each encrypted field with `source_crypto` (old key) and
re-encrypts with itself. Only `{secure, ...}` fields are touched.
re-encrypts with itself. Only `{secure, ...}` fields are touched — including `record`
itself if it IS a `{secure, iv, data}` blob (the file-storage pattern).
Rotation must fail loud: a per-field decrypt failure raises, and so does a blob nested
deeper than `traversal_level` — silently leaving it under the old key would strand it
once the old key's wrapped-key record is deleted below. If you nest blobs deeper than
the default `traversal_level=2`, pass a higher `traversal_level` or flatten the record
first.
## Storage patterns
+1 -1
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@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
[project]
name = "envelope_crypto"
version = "0.1.3"
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 = [
+124 -20
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@@ -44,10 +44,22 @@ set, then re-encrypt existing records old -> new:
for record in caller_iter():
caller_update(new_crypto.reencrypt(crypto, record))
reencrypt/is_encrypted_record/decrypt_record all detect a bare {secure, iv, data}
blob used AS the whole record (the file-storage pattern), not just blobs nested
under a key. reencrypt fails loud (raises) rather than silently leaving a field
under the old key — including when a blob sits deeper than `traversal_level`;
is_encrypted_record falls back to an unbounded-depth scan past traversal_level so
it reliably catches leftovers as a post-rotation audit.
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.
@@ -113,6 +125,24 @@ def _fingerprint_of(public_key) -> str:
return base64.b64encode(digest.finalize()).decode()
def _is_blob(value: Any) -> bool:
"""return whether value has the {secure, iv, data} encrypted-blob shape"""
return isinstance(value, dict) and value.get("secure") is True and "iv" in value and "data" in value
def _has_encrypted_field(record: Any) -> bool:
"""unbounded-depth scan: does record (or anything nested under it) contain a blob
used to detect a blob left behind by a depth-limited traversal — no traversal_level
cutoff here, since the whole point is to catch what a bounded pass would miss.
"""
if not isinstance(record, dict):
return False
if _is_blob(record):
return True
return any(_has_encrypted_field(value) for value in record.values())
def _load_public_key(key_data: bytes):
"""load a PEM or OpenSSH public key, normalizing non-key input to ValueError
@@ -163,7 +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")
@@ -174,7 +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, "
@@ -268,12 +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)
@@ -318,13 +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)
@@ -348,6 +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")
@@ -373,25 +435,42 @@ class EnvelopeCrypto:
key. only {secure, iv, data} fields are touched; plaintext fields are left
as-is. returns a new dict; the input is not mutated. used during rotation.
if `record` itself is a {secure, iv, data} blob (the file-storage pattern, where
the blob IS the whole document) it is re-encrypted directly and the result is
returned in place of `record` — not nested under a key.
unlike decrypt_record (which logs a failed field and leaves it encrypted), a
per-field decrypt failure here RAISES — rotation must fail loud, since silently
keeping a field under the old key would lose it once the old key is retired.
keeping a field under the old key would lose it once the old key is retired. for
the same reason, a blob nested DEEPER than `traversal_level` also RAISES instead
of being silently left under the old key: the caller either needs a higher
`traversal_level` or must flatten the record before rotation.
traversal recurses into nested DICTS only (up to `traversal_level`); a blob nested
inside a LIST is NOT re-encrypted. records in this scheme key blobs by field name,
not inside arrays, so this doesn't arise in practice — but if you store
list-nested blobs, flatten them to dict fields before rotation or they'll be left
under the old key.
traversal recurses into nested DICTS only; a blob nested inside a LIST is NOT
re-encrypted and is NOT covered by the depth-limit raise above. records in this
scheme key blobs by field name, not inside arrays, so this doesn't arise in
practice — but if you store list-nested blobs, flatten them to dict fields before
rotation or they'll be silently left under the old key.
"""
if not self.master_key:
raise ValueError("destination not initialized with data key")
if _is_blob(record):
return self.encrypt_data(source_crypto.decrypt_data(record))
result = copy.deepcopy(record)
for key, value in record.items():
if isinstance(value, dict) and value.get("secure") is True and "iv" in value and "data" in value:
if _is_blob(value):
result[key] = self.encrypt_data(source_crypto.decrypt_data(value))
elif traversal_level > 0 and isinstance(value, dict):
elif isinstance(value, dict):
if traversal_level > 0:
result[key] = self.reencrypt(source_crypto, value, traversal_level - 1)
elif _has_encrypted_field(value):
raise ValueError(
f"reencrypt: field {key!r} contains an encrypted blob nested deeper "
"than traversal_level; increase traversal_level or flatten the record "
"before rotation — leaving it would strand the field under the old key"
)
return result
@@ -404,14 +483,24 @@ PCICrypto = EnvelopeCrypto # deprecated legacy alias; remove after all systems
def is_encrypted_record(record, traversal_level: int = 2) -> bool:
"""return whether a record has any encrypted ({secure, iv, data}) fields
checks `record` itself (the file-storage pattern stores the blob AS the whole
document, not nested under a key) as well as fields up to `traversal_level` deep.
beyond that bounded pass, this ALSO does an unbounded-depth scan before giving up —
so a blob left behind by a shallower decrypt_record/reencrypt call (nested deeper
than their traversal_level) is still reported as encrypted. this makes the function
safe to use as a leftover-detecting post-rotation audit: it never returns False for
a record that still contains a blob, at any depth.
aliases: is_encrypted_document, is_encrypted_dict — same function
"""
if not isinstance(record, dict):
return False
if _is_blob(record):
return True
for value in record.values():
if isinstance(value, dict) and value.get("secure") is True:
if "iv" in value and "data" in value:
if _is_blob(value):
return True
if traversal_level > 0:
@@ -420,12 +509,20 @@ def is_encrypted_record(record, traversal_level: int = 2) -> bool:
return True
return False
return any(_has_encrypted_field(value) for value in record.values())
def decrypt_record(crypto: EnvelopeCrypto, record, traversal_level: int = 2) -> dict:
def decrypt_record(crypto: EnvelopeCrypto, record, traversal_level: int = 2) -> Union[dict, Any]:
"""decrypt a record's encrypted fields into a new dict (up to traversal_level deep)
if `record` itself is a {secure, iv, data} blob (the file-storage pattern, where the
blob IS the whole document) it is decrypted directly and the decrypted value
(dict or string — see decrypt_data) is returned in place of `record`.
failures on a single field are logged and that field is left encrypted, so a
partial failure is visible (the {secure,...} blob remains) rather than silent.
partial failure is visible (the {secure,...} blob remains) rather than silent. a
failure decrypting `record` itself (the self-blob case above) is likewise logged
and the still-encrypted blob is returned unchanged.
aliases: decrypt_document, decrypt_dict — same function
"""
@@ -434,9 +531,16 @@ def decrypt_record(crypto: EnvelopeCrypto, record, traversal_level: int = 2) ->
if not isinstance(record, dict):
return record
if _is_blob(record):
try:
return crypto.decrypt_data(record)
except Exception:
_log.exception("failed to decrypt record")
return copy.deepcopy(record)
result = copy.deepcopy(record)
for key, value in record.items():
if isinstance(value, dict) and value.get("secure") is True and "iv" in value and "data" in value:
if _is_blob(value):
try:
result[key] = crypto.decrypt_data(value)
except Exception: