A flat-file alternative to the SQLite chatlog backend with runtime
switching, full migration tooling, integrity verification, and a
synthetic load harness. SQLite remains the default; both backends share
one dispatch layer (db_backend_t vtable) so callers don't change.
Storage layout
- Per-contact append-only `flatlog/<account>/<contact>/history.log`
under XDG_DATA_HOME, one line per message
- Single-line file header with embedded format-version marker
(FLATFILE_FORMAT_VERSION); reader warns on missing or mismatched
marker, writer and checker stay in sync via preprocessor
stringification
- Deterministic key=value metadata (`id`, `aid`, `corrects`, `to`,
`to_res`, `read`) plus escaped body \u2014 `\|`, `\]`, `\\`, `\n`, `\r`
literals prevent log injection
- Sparse byte-offset index (FF_INDEX_STEP=500) per contact for
O(log n) time-range lookups; rebuilt on inode / size / mtime
change, extended in-place when the file just grew
- Per-contact GHashTable caches for archive_id presence and
stanza_id \u2192 from_jid mapping (O(1) MAM dedup, O(1) LMC sender
validation)
Hardening
- Path-traversal protection: JID directory name normalisation
(`@` \u2192 `_at_`, slashes and `..` rejected at construction); every
per-contact path is anchored under the account's flatlog/
directory and validated before open
- Symlink-attack protection: every fopen / open uses O_NOFOLLOW; on
ELOOP the operation aborts with an error rather than following
- Filesystem permissions: log files created with mode 0600,
directories with mode 0700; both enforced at creation, verified
on each open and reported on drift by `/history verify`
- Atomic crash-safe export: write to a temp file via mkstemp (mode
0600, random suffix, no name collisions between concurrent
exports), fsync, then rename \u2014 partial state never replaces the
live file
- Concurrency: advisory flock(LOCK_EX) held for the duration of
every write, including append from live messages and full rewrite
from export, so two profanity processes can't interleave bytes
on the same log
- DoS / abuse guards:
* FF_MAX_LINE_LEN = 10 MB \u2014 lines longer than this are rejected
at read with a warning; the parser will not allocate
unbounded memory for a single record
* FF_MAX_LMC_DEPTH = 100 \u2014 `corrects:` chain walk stops at this
depth and emits a warning, preventing a malicious correction
cycle from spinning the apply pass
* FF_VERSION_SCAN_MAX = 16 \u2014 header version probe never reads
past 16 leading comment lines, even on garbage input
* Empty / inverted byte-range early-return in page-up read path
so a malformed time filter cannot cause an unbounded scan
* Zero-entry index guard so a file whose every line failed to
parse cannot cause a NULL deref on later page-up
- LMC sender validation: an incoming correction whose sender does
not match the original message's sender is rejected at write
time and surfaced via cons_show_error; a cycle in the apply pass
is broken via a visited-set
- jid_create_from_bare_and_resource treats NULL, empty string, and
the literal "(null)" as no resource and returns a bare jid;
similar normalisation for barejid eliminates the legacy
"user@host/(null)" artefact that leaked into stored fulljids
whenever g_strdup_printf("%s", NULL) ran inside create_fulljid
Commands
- `/history switch sqlite|flatfile` \u2014 runtime backend swap, closes
the old backend and opens the new one without reconnecting
- `/history export [<jid>]` \u2014 SQLite -> flat-file, merging with any
existing flatlog (dedup keyed on a SHA-256 hash mixing stanza_id,
timestamp, from_jid, body \u2014 robust against id reuse by older
clients)
- `/history import [<jid>]` \u2014 flat-file -> SQLite, same merge
semantics, runs inside a single SQLite transaction with rollback
on per-contact failure
- `/history verify [<jid>]` \u2014 integrity check; emits a structured
list of issues (ERROR / WARNING / INFO) per file:
* file-level: missing log, wrong permissions (\u2260 0600), UTF-8
BOM present, CRLF line endings, empty file
* line-level: invalid UTF-8 (with byte offset), embedded
control characters, unparsable lines, timestamps out of
order, duplicate `id:` and `aid:` (tracked separately so a
stanza/archive id collision isn't double-reported)
* cross-line: broken `corrects:` references whose target id is
not present in the file
- `/history backend` \u2014 show currently active backend
- Active backend indicator `[sqlite]` / `[flatfile]` in the status
bar next to the JID
- Roster-JID autocomplete for verify / export / import
- export and import open a SQLite handle on demand when the
flatfile backend is currently active, so migration works
regardless of which backend is live
Tests
- Unit: database_export (parser round-trip, escape/unescape, dedup
key stability, JID normalisation), database_stress (14 cases
exercising rapid writes, large messages, deep LMC chains, MAM
dedup, concurrent contacts)
- Functional: history persistence across reconnects, export /
import round-trip with content equality, MUC migration,
timestamp normalisation across timezones
- Bench harness P1\u2013P5 (synthetic load: bulk insert, time-range
read, page-up scroll, MAM ingest, mixed workload) and failure
modes F1\u2013F17 (page-up cursor and forward-iteration symmetry,
oversized lines, MAM dedup, LMC depth and cycles, BOM/CRLF,
missing log, empty file, mtime+inode flip, broken corrects, etc.)
- All bench tests integrate with the existing make targets and
emit CSV rows for baseline comparison
Author: jabber.developer2 <jabber.developer2@jabber.space>
Reviewed-by: jabber.developer <jabber.developer@jabber.space>
CProof
CProof is a console based XMPP chat client based on Profanity.
See the Quick Start Guide for information on installing and using CProof.
Project
CProof enables you to communicate with privacy, freedom and comfort. Our open-source chat application delivers secure, end-to-end encrypted messaging (OTR, PGP, OMEMO, OX) built on the trusted XMPP protocol. With a decentralized design, you can connect directly or even host your own server, keeping your data in your hands. Whether you're chatting with friends or collaborating securely, CProof makes private communication simple, reliable, and truly yours.
Installation
Check our installation guide for detailed instructions.
How to contribute
See our Helping Out page for a concise summary of ways to help us.
Review the Contributing Guide and Code Overview pages for advanced technical details.
Getting help
Prior to asking questions, check our User Guide, then check out the FAQ.
If you are still having a problem then search the issue tracker.
As a last resort, feel free to write us on support@jabber.tech or create a new issue depending on what your problem is.
Links
Website
Feel free to visit our website: jabber.space.
You may also check the repository if you like, available on git.jabber.space/devs/profanity.
Plugins
Plugins repository: https://git.jabber.space/devs/cproof-plugins
