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42643be662 .. issue-220-apps-by-hostname
Author SHA1 Message Date
sneak 21f7bf6f23 SWW_APPS: an app's Core Rule Set fixes apply only to the hostnames that serve it (closes #220)
check / check (push) Failing after 1m34s
Details 
gitea's fixes (its parameters, its cookies and gitea.conf) now apply
only to a hostname SWW_APPS lists gitea for, or to every hostname while
it is unset. Each app's fixes are one .conf file, whose first rule skips
the rest unless Inspect sets tx.app_<name>, and one entry in apps.

A hostname in SWW_APPS that is not a DNS name, such as *.example.com,
stops the start. Unset, SWW_APPS is logged at start as null; set
empty, as "".

Model: opus-5-5
 2026-11-07 13:40:33 +00:00
clawbot beb503b233 Rename the program to sww and its deciding daemon to discriminator (closes #218) (#221)
check / check (push) Failing after 1m34s
Details
2026-11-07 06:51:06 +01:00
15 changed files with 695 additions and 267 deletions
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README.md
+133 -127
View File
@@ -7,8 +7,8 @@ requests of scrapers, scanners and other abusers before they reach an app.
## What it does
A web application firewall reads each request on its way to a web app and
refuses the ones that look like abuse. `smallwebwaf` is one binary, shipped in
one image, with two commands that do this together:
refuses the ones that look like abuse. `smallwebwaf` is one program, `sww`,
shipped in one image, with two commands that do this together:
- `sww rproxy` is a small reverse proxy in front of one app. traefik routes to
it. It asks `discriminator` about each request, passes the allowed ones to the
@@ -194,7 +194,8 @@ account, a key, a token or an alert destination stays off until you give one.
contents are the value, less one newline at the end. Setting both forms stops
the start. `SWW_LOG_REMOTE_TLS_CA_FILE` and
`SWW_CORE_RULE_SET_EXCLUSIONS_FILE` already name a file, so they have no
`_FILE` form. No `SWRP_` setting has one, since `rproxy` never touches disk.
`_FILE` form. `SWW_COMMAND` cannot be given as a file. No `SWRP_` setting has
one, since `rproxy` never touches disk.
- A duration is Go's syntax, with `d` for days: `90s`, `15m`, `24h`, `7d`.
- A size is a number of bytes with an optional `K`, `M` or `G`, in powers of
1024: `512K`, `100M`, `5G`.
@@ -214,122 +215,123 @@ account, a key, a token or an alert destination stays off until you give one.
Every setting the code reads, with its default:
| Variable | Default | What it does |
| ---------------------------------------- | ------------------------------------------------------------------------------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `SWW_COMMAND` | `rproxy` | Which command the image runs, and its health check checks: `rproxy` or `discriminator`. |
| `SWRP_WAF_BACKEND` | required | `discriminator`'s URL, such as `http://discriminator:8080`. |
| `SWRP_UPSTREAM_URL` | `http://127.0.0.1:8081` | The app's URL: a scheme, a host and an optional port, nothing more. |
| `SWRP_LISTEN_ADDR` | `:8080` | Where `rproxy` listens; leave the host part empty. |
| `SWRP_TRUSTED_PROXIES` | `10.0.0.0/8,172.16.0.0/12,192.168.0.0/16` | The netblocks whose `X-Forwarded-For` `rproxy` believes; set but empty, it believes none. |
| `SWRP_TIMEOUT_MS` | `2000` | How long `rproxy` waits for `discriminator`'s answer to a question and to a report, in milliseconds. |
| `SWRP_DEFAULT_DISPOSITION` | `allow` | What `rproxy` does with a request when `discriminator` cannot be reached or does not answer in time: `allow` passes it to the app, `deny` answers `503`. |
| `SWRP_MAX_REQUEST_SIZE` | `100M` | The largest request body, a size or `off`; a larger one is answered `413`. |
| `SWRP_MAX_RESPONSE_SIZE` | `1G` | The largest response body, a size or `off`; a larger one is answered `502`, or cut off once it has started. |
| `SWRP_MAX_REQUEST_TIME_MS` | `60000` | How long the visitor may take to send its request line and headers, and then the whole request to reach the app, in milliseconds or `off`. |
| `SWRP_MAX_RESPONSE_TIME_MS` | `1800000` | How long the answer may take, from the end of the request to its last byte reaching the visitor, in milliseconds or `off`. |
| `SWW_LISTEN_ADDR` | `:8080` | Where `discriminator` listens; leave the host part empty. |
| `SWW_INSTANCE_NAME` | the container's host name | The name in every line `discriminator` logs, and in every alert and metric, such as `fsn1/discriminator`. |
| `SWW_MODE` | `enforce` | `observe` refuses nothing and makes no ban; each log line says what `enforce` would have done. |
| `SWW_IPV6_GROUP_PREFIX` | `64` | The prefix length of the IPv6 netblock that counts as one client, from 32 to 128. |
| `SWW_MAX_TRACKED_CLIENTS` | `20000` | The most clients kept, in memory and in `clients.json`; the least recently seen is dropped first. |
| `SWW_MAX_BANS` | `5000` | The most bans `discriminator` keeps of its own; bans an admin made do not count. |
| `SWW_ALLOW_NETS` | empty | Netblocks whose clients skip every check, such as your monitoring. |
| `SWW_RATE_LIMIT_EXEMPT_NETS` | empty | Netblocks whose clients the request and byte limits neither count nor refuse. |
| `SWW_DENY_NETS` | empty | Netblocks whose clients are refused. |
| `SWW_RATE_LIMIT_PER_MINUTE` | `120` | The most requests a client may make in a minute, a count or `off`; one more bans it. |
| `SWW_RATE_LIMIT_PER_HOUR` | `1500` | The most requests a client may make in an hour, a count or `off`; one more bans it. |
| `SWW_RATE_LIMIT_PER_DAY` | `6000` | The most requests a client may make in a day, a count or `off`; one more bans it. |
| `SWW_RATE_LIMIT_EXEMPT_PATHS` | empty | Path prefixes whose requests the request and byte limits neither count nor refuse, such as `/assets/`. |
| `SWW_BYTES_LIMIT_PER_MINUTE` | `off` | The most bytes a client's requests may carry in a minute, a size or `off`; the request that takes a client past any byte limit bans it. |
| `SWW_BYTES_LIMIT_PER_HOUR` | `50G` | The most bytes a client's requests may carry in an hour, a size or `off`. |
| `SWW_BYTES_LIMIT_PER_DAY` | `100G` | The most bytes a client's requests may carry in a day, a size or `off`. |
| `SWW_BYTES_COUNT` | `both` | Which body bytes the byte limits count: `response`, `request` or `both`. |
| `SWW_ERROR_BURST_THRESHOLD` | `30` | The most refusals by a rule file, a trap path or the Core Rule Set a client may get in a minute, a count or `off`; one more bans it. |
| `SWW_BAN_RESPONSE` | `403` | How a refused client is answered: `403`, `429` or `close`, which drops the connection. |
| `SWW_LIMIT_BAN_DURATION` | `1h` | The ban for a first broken limit. |
| `SWW_LIMIT_BAN_REPEAT_WINDOW` | `24h` | A limit broken again within this time after the last such ban ended gets a ban three times as long. |
| `SWW_MAX_BAN_DURATION` | `7d` | A ban for a broken limit that would be longer than this is permanent instead. |
| `SWW_ATTACK_BAN_DURATION` | `7d` | The ban for a first clear sign of attack: a `ban` rule or a trap path. |
| `SWW_BAN_SCOPE_V4_PREFIX` | `32` | The prefix length of the netblock a ban on an IPv4 client covers, from 0 to 32. |
| `SWW_LOOKUP_SOURCE` | `geojs` | Where each client's AS number and country come from: `geojs`, a web service, `file`, or `off`. |
| `SWW_LOOKUP_DB_PATH` | empty | The IPinfo Lite database file, in its `.mmdb` form, read while the source is `file`. |
| `SWW_LOOKUP_TIMEOUT` | `800ms` | How long a request waits for its client's first GeoJS answer when a setting needs it, and how long a request to GeoJS may take. |
| `SWW_ADD_LOOKUP_HEADERS` | `false` | `true` passes the app the client's AS number and country in `X-Client-ASN` and `X-Client-Country`. |
| `SWW_DENIED_COUNTRIES` | empty | Countries whose clients are refused, such as `cn,ru`. |
| `SWW_EXCLUSIVELY_ALLOWED_COUNTRIES` | empty | When set, the only countries whose clients get through; a client the lookup cannot place is refused too. |
| `SWW_ASN_LIMIT_PERCENT` | empty | AS numbers whose clients get a percentage of every request and byte limit, such as `AS14061:50,AS16276:25`. |
| `SWW_COUNTRY_LIMIT_PERCENT` | empty | The same by country, such as `cn:25`. |
| `SWW_ASN_BYTES_PERCENT` | empty | A percentage of the byte limits alone for the AS numbers listed, in place of their `SWW_ASN_LIMIT_PERCENT`. |
| `SWW_COUNTRY_BYTES_PERCENT` | empty | A percentage of the byte limits alone for the countries listed, in place of their `SWW_COUNTRY_LIMIT_PERCENT`. |
| `SWW_UNKNOWN_LIMIT_PERCENT` | `100` | The percentage of every limit a client without a country gets. |
| `SWW_ASN_LIMIT_PERCENT_URL` | unset | The URL of a text file of `AS<number>:<percent>` lines, fetched like a blocklist; where it and `SWW_ASN_LIMIT_PERCENT` both give a percentage, the lower applies. |
| `SWW_RULES_DIR` | `/etc/sww/rules.d` | The directory of the rule files, read at start and again when a file there changes. |
| `SWW_RULES_ENABLED` | `true` | `false` reads no rule file. |
| `SWW_TRAP_PATHS` | empty | Paths only scanners ask for, such as `/wp-login.php,/xmlrpc.php`; a request for one bans the client. |
| `SWW_WAF_MODE` | `block` | What the Core Rule Set does with a match: `block` refuses it with `403`, `detect` only logs and alerts it, `off` runs no rule. |
| `SWW_WAF_PARANOIA_LEVEL` | `1` | The Core Rule Set's paranoia level, from 1 to 4; each level up finds more attacks and takes more ordinary requests for attacks. |
| `SWW_WAF_ANOMALY_THRESHOLD` | `5` | The Core Rule Set score at which a request is a match, a whole number or `off`; one critical rule scores 5. |
| `SWW_WAF_DISABLED_RULES` | `920340,920420,920440,920640,930130,930140` | Core Rule Set rule ids switched off; a list you give replaces the default, so repeat these six to keep them off. |
| `SWW_WAF_EXEMPT_PATHS` | empty | Path prefixes the Core Rule Set does not inspect. |
| `SWW_WAF_BODY_LIMIT` | `off` | How much of a request body the Core Rule Set reads, a size up to `64K`; `off` reads none. |
| `SWW_CORE_RULE_SET_EXCLUSIONS_FILE` | unset | A file of Core Rule Set exclusions, as Coraza directives, that switch rules off for some fields or paths only. |
| `SWW_BLOCKLIST_URLS` | empty | Blocklists to fetch, text files of addresses and netblocks one to a line, such as `https://www.spamhaus.org/drop/drop.txt`. |
| `SWW_BLOCKLIST_REFRESH` | `24h` | How long after a list was last tried it is fetched again, `1h` or more. |
| `SWW_BLOCKLIST_ACTION` | `deny` | What a client on a blocklist gets: `deny`, `limit:<percent>` of every limit, or `log`. |
| `SWW_DNSBL_ZONES` | empty | DNS blocklists asked about each new client in the background, such as `dnsbl.dronebl.org`. |
| `SWW_DNSBL_RESOLVER` | unset | The resolver the zones are asked through, an IP address with an optional port; unset, the host's resolver is used. |
| `SWW_ABUSEIPDB_KEY` | unset | The key of your AbuseIPDB account; set, a client that has committed an offence is checked in the background. |
| `SWW_ABUSEIPDB_MIN_SCORE` | `75` | The least AbuseIPDB abuse confidence score, from 0 to 100, that is a hit. |
| `SWW_ABUSEIPDB_DAILY_BUDGET` | `900` | The most AbuseIPDB checks made in a day. |
| `SWW_CROWDSEC_LAPI_URL` | unset | The local API of a CrowdSec engine you run, such as `http://172.17.0.1:8080`; its decision list is fetched every minute, and a listed client is banned. |
| `SWW_CROWDSEC_LAPI_KEY` | unset | The key the engine gave for `smallwebwaf`, as `cscli bouncers add smallwebwaf` prints it; set with the URL, never alone. |
| `SWW_REPUTATION_ACTION` | `limit:25` | What a client listed by a DNS blocklist, or scored a hit by AbuseIPDB, gets: `deny`, `limit:<percent>` or `log`. |
| `SWW_REPUTATION_CACHE_TTL` | `24h` | How long a DNS blocklist verdict or an AbuseIPDB score is used. |
| `SWW_REPUTATION_TIMEOUT` | `2s` | How long a DNS blocklist query or an AbuseIPDB check may take. |
| `SWW_STATE_DIR` | `/var/lib/sww` | The directory of the state files, an absolute path. |
| `SWW_STATE_WRITE_DELAY` | `10s` | How long `bans.json` waits to be written after a ban is made, lifted or made permanent. |
| `SWW_STATE_COUNTER_INTERVAL` | `15m` | How often every state file is written. |
| `SWW_LOG_LEVEL` | `info` | The least severe of `discriminator`'s own messages that are written: `debug`, `info`, `warn` or `error`; request lines are always written. |
| `SWW_LOG_REQUEST_HEADERS` | `accept,accept-language,accept-encoding,content-type,origin,range` | The request headers whose values the request log records; `Authorization` and `Cookie` are never recorded. |
| `SWW_LOG_REMOTE_URL` | unset | A syslog server that also gets every line `discriminator` writes: `syslog+udp://`, `syslog+tcp://` or `syslog+tls://` with a host and a port. |
| `SWW_LOG_REMOTE_TLS_CA_FILE` | unset | A file of PEM certificates a `syslog+tls` server's certificate must chain to, instead of the host's own. |
| `SWW_LOG_REMOTE_BUFFER` | `10000` | The most lines held while they wait to be sent; past it, the oldest is dropped. |
| `SWW_LOG_REMOTE_FACILITY` | `local0` | The syslog facility of each record sent. |
| `SWW_LOG_REMOTE_APP_NAME` | `SWW_INSTANCE_NAME` | The app name in each syslog record, 1 to 48 printable ASCII characters without a space. |
| `SWW_ADMIN_TOKEN` | unset | The bearer token for the ban and client endpoints, at least 32 characters; unset, they answer `404`. |
| `SWW_METRICS_TOKEN` | unset | The bearer token for `/_sww/metrics`, at least 32 characters; unset, the metrics are off. |
| `SWW_METRICS_TOP_N` | `50` | How many AS numbers and how many countries get metric series of their own; the rest are summed as `other`. |
| `SWW_ALERT_WEBHOOK_URL` | unset | A webhook each alert is posted to as a JSON object. |
| `SWW_ALERT_WEBHOOK_HEADERS` | empty | Headers sent with each post, a list of `Name:value`, such as `Authorization:Bearer <token>`. |
| `SWW_ALERT_SLACK_WEBHOOK_URL` | unset | A Slack incoming webhook each alert is posted to as a message. |
| `SWW_ALERT_NTFY_URL` | unset | An ntfy topic each alert is published to, as its full URL, such as `https://ntfy.sh/my-alerts`. |
| `SWW_ALERT_NTFY_TOKEN` | unset | An ntfy access token sent with each alert. |
| `SWW_ALERT_EVENTS` | `ban,permanent_ban,waf_block,anomaly,reputation_hit,source_failure,file_error` | The events alerts are sent for; the hourly `summary` is sent whatever it says. |
| `SWW_ALERT_COOLDOWN` | `15m` | How long after an alert its repeats are held back and counted, a duration or `off`. |
| `SWW_ALERT_MAX_PER_HOUR` | `60` | The most alerts sent in an hour, a number or `off`; the rest are counted in the hour's `summary`. |
| `SWW_ANOMALY_CLIENT_REQUESTS_PER_MINUTE` | `off` | Alert when one client makes more requests than this in a minute, a count. |
| `SWW_ANOMALY_CLIENT_REQUESTS_PER_HOUR` | `off` | Alert when one client makes more requests than this in an hour, a count. |
| `SWW_ANOMALY_CLIENT_BYTES_PER_MINUTE` | `off` | Alert when one client's requests carry more bytes than this in a minute, a size. |
| `SWW_ANOMALY_CLIENT_BYTES_PER_HOUR` | `off` | Alert when one client's requests carry more bytes than this in an hour, a size. |
| `SWW_ANOMALY_NET_REQUESTS_PER_MINUTE` | `off` | Alert when the netblock around a client makes more requests than this in a minute, a count. |
| `SWW_ANOMALY_NET_REQUESTS_PER_HOUR` | `off` | Alert when the netblock around a client makes more requests than this in an hour, a count. |
| `SWW_ANOMALY_NET_BYTES_PER_MINUTE` | `off` | Alert when the netblock around a client carries more bytes than this in a minute, a size. |
| `SWW_ANOMALY_NET_BYTES_PER_HOUR` | `off` | Alert when the netblock around a client carries more bytes than this in an hour, a size. |
| `SWW_ANOMALY_NET_V4_PREFIX` | `24` | The prefix length of the netblock around an IPv4 client that the `SWW_ANOMALY_NET_` thresholds count, from 0 to 32. |
| `SWW_ANOMALY_NET_V6_PREFIX` | `48` | The prefix length of the netblock around an IPv6 client that the `SWW_ANOMALY_NET_` thresholds count, from 0 to 128. |
| `SWW_ANOMALY_ASN_REQUESTS_PER_MINUTE` | `off` | Alert when one AS number makes more requests than this in a minute, a count. |
| `SWW_ANOMALY_ASN_REQUESTS_PER_HOUR` | `off` | Alert when one AS number makes more requests than this in an hour, a count. |
| `SWW_ANOMALY_ASN_BYTES_PER_MINUTE` | `off` | Alert when one AS number carries more bytes than this in a minute, a size. |
| `SWW_ANOMALY_ASN_BYTES_PER_HOUR` | `off` | Alert when one AS number carries more bytes than this in an hour, a size. |
| `SWW_ANOMALY_TOTAL_REQUESTS_PER_MINUTE` | `off` | Alert when the whole service gets more requests than this in a minute, a count. |
| `SWW_ANOMALY_TOTAL_REQUESTS_PER_HOUR` | `off` | Alert when the whole service gets more requests than this in an hour, a count. |
| `SWW_ANOMALY_TOTAL_BYTES_PER_MINUTE` | `off` | Alert when the whole service carries more bytes than this in a minute, a size. |
| `SWW_ANOMALY_TOTAL_BYTES_PER_HOUR` | `off` | Alert when the whole service carries more bytes than this in an hour, a size. |
| `SWW_WATCH_NETS` | empty | Named netblocks the `SWW_WATCH_` thresholds count each as a whole, such as `office=203.0.113.0/24,scraper-x=198.51.100.0/22`. |
| `SWW_WATCH_REQUESTS_PER_MINUTE` | `off` | Alert when a watched netblock makes more requests than this in a minute, a count. |
| `SWW_WATCH_REQUESTS_PER_HOUR` | `off` | Alert when a watched netblock makes more requests than this in an hour, a count. |
| `SWW_WATCH_BYTES_PER_MINUTE` | `off` | Alert when a watched netblock carries more bytes than this in a minute, a size. |
| `SWW_WATCH_BYTES_PER_HOUR` | `off` | Alert when a watched netblock carries more bytes than this in an hour, a size. |
| Variable | Default | What it does |
| ---------------------------------------- | ------------------------------------------------------------------------------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `SWW_COMMAND` | `rproxy` | Which command the image runs, and its health check checks: `rproxy` or `discriminator`. |
| `SWRP_WAF_BACKEND` | required | `discriminator`'s URL, such as `http://discriminator:8080`. |
| `SWRP_UPSTREAM_URL` | `http://127.0.0.1:8081` | The app's URL: a scheme, a host and an optional port, nothing more. |
| `SWRP_LISTEN_ADDR` | `:8080` | Where `rproxy` listens; leave the host part empty. |
| `SWRP_TRUSTED_PROXIES` | `10.0.0.0/8,172.16.0.0/12,192.168.0.0/16` | The netblocks whose `X-Forwarded-For` `rproxy` believes; set but empty, it believes none. |
| `SWRP_TIMEOUT_MS` | `2000` | How long `rproxy` waits for `discriminator`'s answer to a question and to a report, in milliseconds. |
| `SWRP_DEFAULT_DISPOSITION` | `allow` | What `rproxy` does with a request when `discriminator` cannot be reached or does not answer in time: `allow` passes it to the app, `deny` answers `503`. |
| `SWRP_MAX_REQUEST_SIZE` | `100M` | The largest request body, a size or `off`; a larger one is answered `413`. |
| `SWRP_MAX_RESPONSE_SIZE` | `1G` | The largest response body, a size or `off`; a larger one is answered `502`, or cut off once it has started. |
| `SWRP_MAX_REQUEST_TIME_MS` | `60000` | How long the visitor may take to send its request line and headers, and then the whole request to reach the app, in milliseconds or `off`. |
| `SWRP_MAX_RESPONSE_TIME_MS` | `1800000` | How long the answer may take, from the end of the request to its last byte reaching the visitor, in milliseconds or `off`. |
| `SWW_LISTEN_ADDR` | `:8080` | Where `discriminator` listens; leave the host part empty. |
| `SWW_INSTANCE_NAME` | the container's host name | The name in every line `discriminator` logs, and in every alert and metric, such as `fsn1/discriminator`. |
| `SWW_MODE` | `enforce` | `observe` refuses nothing and makes no ban; each log line says what `enforce` would have done. |
| `SWW_IPV6_GROUP_PREFIX` | `64` | The prefix length of the IPv6 netblock that counts as one client, from 32 to 128. |
| `SWW_MAX_TRACKED_CLIENTS` | `20000` | The most clients kept, in memory and in `clients.json`; the least recently seen is dropped first. |
| `SWW_MAX_BANS` | `5000` | The most bans `discriminator` keeps of its own; bans an admin made do not count. |
| `SWW_ALLOW_NETS` | empty | Netblocks whose clients skip every check, such as your monitoring. |
| `SWW_RATE_LIMIT_EXEMPT_NETS` | empty | Netblocks whose clients the request and byte limits neither count nor refuse. |
| `SWW_DENY_NETS` | empty | Netblocks whose clients are refused. |
| `SWW_RATE_LIMIT_PER_MINUTE` | `120` | The most requests a client may make in a minute, a count or `off`; one more bans it. |
| `SWW_RATE_LIMIT_PER_HOUR` | `1500` | The most requests a client may make in an hour, a count or `off`; one more bans it. |
| `SWW_RATE_LIMIT_PER_DAY` | `6000` | The most requests a client may make in a day, a count or `off`; one more bans it. |
| `SWW_RATE_LIMIT_EXEMPT_PATHS` | empty | Path prefixes whose requests the request and byte limits neither count nor refuse, such as `/assets/`. |
| `SWW_BYTES_LIMIT_PER_MINUTE` | `off` | The most bytes a client's requests may carry in a minute, a size or `off`; the request that takes a client past any byte limit bans it. |
| `SWW_BYTES_LIMIT_PER_HOUR` | `50G` | The most bytes a client's requests may carry in an hour, a size or `off`. |
| `SWW_BYTES_LIMIT_PER_DAY` | `100G` | The most bytes a client's requests may carry in a day, a size or `off`. |
| `SWW_BYTES_COUNT` | `both` | Which body bytes the byte limits count: `response`, `request` or `both`. |
| `SWW_ERROR_BURST_THRESHOLD` | `30` | The most refusals by a rule file, a trap path or the Core Rule Set a client may get in a minute, a count or `off`; one more bans it. |
| `SWW_BAN_RESPONSE` | `403` | How a refused client is answered: `403`, `429` or `close`, which drops the connection. |
| `SWW_LIMIT_BAN_DURATION` | `1h` | The ban for a first broken limit. |
| `SWW_LIMIT_BAN_REPEAT_WINDOW` | `24h` | A limit broken again within this time after the last such ban ended gets a ban three times as long. |
| `SWW_MAX_BAN_DURATION` | `7d` | A ban for a broken limit that would be longer than this is permanent instead. |
| `SWW_ATTACK_BAN_DURATION` | `7d` | The ban for a first clear sign of attack: a `ban` rule or a trap path. |
| `SWW_BAN_SCOPE_V4_PREFIX` | `32` | The prefix length of the netblock a ban on an IPv4 client covers, from 0 to 32. |
| `SWW_LOOKUP_SOURCE` | `geojs` | Where each client's AS number and country come from: `geojs`, a web service, `file`, or `off`. |
| `SWW_LOOKUP_DB_PATH` | empty | The IPinfo Lite database file, in its `.mmdb` form, read while the source is `file`. |
| `SWW_LOOKUP_TIMEOUT` | `800ms` | How long a request waits for its client's first GeoJS answer when a setting needs it, and how long a request to GeoJS may take. |
| `SWW_ADD_LOOKUP_HEADERS` | `false` | `true` passes the app the client's AS number and country in `X-Client-ASN` and `X-Client-Country`. |
| `SWW_DENIED_COUNTRIES` | empty | Countries whose clients are refused, such as `cn,ru`. |
| `SWW_EXCLUSIVELY_ALLOWED_COUNTRIES` | empty | When set, the only countries whose clients get through; a client the lookup cannot place is refused too. |
| `SWW_ASN_LIMIT_PERCENT` | empty | AS numbers whose clients get a percentage of every request and byte limit, such as `AS14061:50,AS16276:25`. |
| `SWW_COUNTRY_LIMIT_PERCENT` | empty | The same by country, such as `cn:25`. |
| `SWW_ASN_BYTES_PERCENT` | empty | A percentage of the byte limits alone for the AS numbers listed, in place of their `SWW_ASN_LIMIT_PERCENT`. |
| `SWW_COUNTRY_BYTES_PERCENT` | empty | A percentage of the byte limits alone for the countries listed, in place of their `SWW_COUNTRY_LIMIT_PERCENT`. |
| `SWW_UNKNOWN_LIMIT_PERCENT` | `100` | The percentage of every limit a client without a country gets. |
| `SWW_ASN_LIMIT_PERCENT_URL` | unset | The URL of a text file of `AS<number>:<percent>` lines, fetched like a blocklist; where it and `SWW_ASN_LIMIT_PERCENT` both give a percentage, the lower applies. |
| `SWW_RULES_DIR` | `/etc/sww/rules.d` | The directory of the rule files, read at start and again when a file there changes. |
| `SWW_RULES_ENABLED` | `true` | `false` reads no rule file. |
| `SWW_TRAP_PATHS` | empty | Paths only scanners ask for, such as `/wp-login.php,/xmlrpc.php`; a request for one bans the client. |
| `SWW_WAF_MODE` | `block` | What the Core Rule Set does with a match: `block` refuses it with `403`, `detect` only logs and alerts it, `off` runs no rule. |
| `SWW_WAF_PARANOIA_LEVEL` | `1` | The Core Rule Set's paranoia level, from 1 to 4; each level up finds more attacks and takes more ordinary requests for attacks. |
| `SWW_WAF_ANOMALY_THRESHOLD` | `5` | The Core Rule Set score at which a request is a match, a whole number or `off`; one critical rule scores 5. |
| `SWW_WAF_DISABLED_RULES` | `920340,920420,920440,920640,930130,930140` | Core Rule Set rule ids switched off; a list you give replaces the default, so repeat these six to keep them off. |
| `SWW_WAF_EXEMPT_PATHS` | empty | Path prefixes the Core Rule Set does not inspect. |
| `SWW_WAF_BODY_LIMIT` | `off` | How much of a request body the Core Rule Set reads, a size up to `64K`; `off` reads none. |
| `SWW_CORE_RULE_SET_EXCLUSIONS_FILE` | unset | A file of Core Rule Set exclusions, as Coraza directives, that switch rules off for some fields or paths only. |
| `SWW_APPS` | unset | The apps each hostname serves, such as `git.example.com:gitea;cloud.example.com:gitea`; only those apps' fixes apply there. Unset, every app's fixes apply to every hostname. |
| `SWW_BLOCKLIST_URLS` | empty | Blocklists to fetch, text files of addresses and netblocks one to a line, such as `https://www.spamhaus.org/drop/drop.txt`. |
| `SWW_BLOCKLIST_REFRESH` | `24h` | How long after a list was last tried it is fetched again, `1h` or more. |
| `SWW_BLOCKLIST_ACTION` | `deny` | What a client on a blocklist gets: `deny`, `limit:<percent>` of every limit, or `log`. |
| `SWW_DNSBL_ZONES` | empty | DNS blocklists asked about each new client in the background, such as `dnsbl.dronebl.org`. |
| `SWW_DNSBL_RESOLVER` | unset | The resolver the zones are asked through, an IP address with an optional port; unset, the host's resolver is used. |
| `SWW_ABUSEIPDB_KEY` | unset | The key of your AbuseIPDB account; set, a client that has committed an offence is checked in the background. |
| `SWW_ABUSEIPDB_MIN_SCORE` | `75` | The least AbuseIPDB abuse confidence score, from 0 to 100, that is a hit. |
| `SWW_ABUSEIPDB_DAILY_BUDGET` | `900` | The most AbuseIPDB checks made in a day. |
| `SWW_CROWDSEC_LAPI_URL` | unset | The local API of a CrowdSec engine you run, such as `http://172.17.0.1:8080`; its decision list is fetched every minute, and a listed client is banned. |
| `SWW_CROWDSEC_LAPI_KEY` | unset | The key the engine gave for `smallwebwaf`, as `cscli bouncers add smallwebwaf` prints it; set with the URL, never alone. |
| `SWW_REPUTATION_ACTION` | `limit:25` | What a client listed by a DNS blocklist, or scored a hit by AbuseIPDB, gets: `deny`, `limit:<percent>` or `log`. |
| `SWW_REPUTATION_CACHE_TTL` | `24h` | How long a DNS blocklist verdict or an AbuseIPDB score is used. |
| `SWW_REPUTATION_TIMEOUT` | `2s` | How long a DNS blocklist query or an AbuseIPDB check may take. |
| `SWW_STATE_DIR` | `/var/lib/sww` | The directory of the state files, an absolute path. |
| `SWW_STATE_WRITE_DELAY` | `10s` | How long `bans.json` waits to be written after a ban is made, lifted or made permanent. |
| `SWW_STATE_COUNTER_INTERVAL` | `15m` | How often every state file is written. |
| `SWW_LOG_LEVEL` | `info` | The least severe of `discriminator`'s own messages that are written: `debug`, `info`, `warn` or `error`; request lines are always written. |
| `SWW_LOG_REQUEST_HEADERS` | `accept,accept-language,accept-encoding,content-type,origin,range` | The request headers whose values the request log records; `Authorization` and `Cookie` are never recorded. |
| `SWW_LOG_REMOTE_URL` | unset | A syslog server that also gets every line `discriminator` writes: `syslog+udp://`, `syslog+tcp://` or `syslog+tls://` with a host and a port. |
| `SWW_LOG_REMOTE_TLS_CA_FILE` | unset | A file of PEM certificates a `syslog+tls` server's certificate must chain to, instead of the host's own. |
| `SWW_LOG_REMOTE_BUFFER` | `10000` | The most lines held while they wait to be sent; past it, the oldest is dropped. |
| `SWW_LOG_REMOTE_FACILITY` | `local0` | The syslog facility of each record sent. |
| `SWW_LOG_REMOTE_APP_NAME` | `SWW_INSTANCE_NAME` | The app name in each syslog record, 1 to 48 printable ASCII characters without a space. |
| `SWW_ADMIN_TOKEN` | unset | The bearer token for the ban and client endpoints, at least 32 characters; unset, they answer `404`. |
| `SWW_METRICS_TOKEN` | unset | The bearer token for `/_sww/metrics`, at least 32 characters; unset, the metrics are off. |
| `SWW_METRICS_TOP_N` | `50` | How many AS numbers and how many countries get metric series of their own; the rest are summed as `other`. |
| `SWW_ALERT_WEBHOOK_URL` | unset | A webhook each alert is posted to as a JSON object. |
| `SWW_ALERT_WEBHOOK_HEADERS` | empty | Headers sent with each post, a list of `Name:value`, such as `Authorization:Bearer <token>`. |
| `SWW_ALERT_SLACK_WEBHOOK_URL` | unset | A Slack incoming webhook each alert is posted to as a message. |
| `SWW_ALERT_NTFY_URL` | unset | An ntfy topic each alert is published to, as its full URL, such as `https://ntfy.sh/my-alerts`. |
| `SWW_ALERT_NTFY_TOKEN` | unset | An ntfy access token sent with each alert. |
| `SWW_ALERT_EVENTS` | `ban,permanent_ban,waf_block,anomaly,reputation_hit,source_failure,file_error` | The events alerts are sent for; the hourly `summary` is sent whatever it says. |
| `SWW_ALERT_COOLDOWN` | `15m` | How long after an alert its repeats are held back and counted, a duration or `off`. |
| `SWW_ALERT_MAX_PER_HOUR` | `60` | The most alerts sent in an hour, a number or `off`; the rest are counted in the hour's `summary`. |
| `SWW_ANOMALY_CLIENT_REQUESTS_PER_MINUTE` | `off` | Alert when one client makes more requests than this in a minute, a count. |
| `SWW_ANOMALY_CLIENT_REQUESTS_PER_HOUR` | `off` | Alert when one client makes more requests than this in an hour, a count. |
| `SWW_ANOMALY_CLIENT_BYTES_PER_MINUTE` | `off` | Alert when one client's requests carry more bytes than this in a minute, a size. |
| `SWW_ANOMALY_CLIENT_BYTES_PER_HOUR` | `off` | Alert when one client's requests carry more bytes than this in an hour, a size. |
| `SWW_ANOMALY_NET_REQUESTS_PER_MINUTE` | `off` | Alert when the netblock around a client makes more requests than this in a minute, a count. |
| `SWW_ANOMALY_NET_REQUESTS_PER_HOUR` | `off` | Alert when the netblock around a client makes more requests than this in an hour, a count. |
| `SWW_ANOMALY_NET_BYTES_PER_MINUTE` | `off` | Alert when the netblock around a client carries more bytes than this in a minute, a size. |
| `SWW_ANOMALY_NET_BYTES_PER_HOUR` | `off` | Alert when the netblock around a client carries more bytes than this in an hour, a size. |
| `SWW_ANOMALY_NET_V4_PREFIX` | `24` | The prefix length of the netblock around an IPv4 client that the `SWW_ANOMALY_NET_` thresholds count, from 0 to 32. |
| `SWW_ANOMALY_NET_V6_PREFIX` | `48` | The prefix length of the netblock around an IPv6 client that the `SWW_ANOMALY_NET_` thresholds count, from 0 to 128. |
| `SWW_ANOMALY_ASN_REQUESTS_PER_MINUTE` | `off` | Alert when one AS number makes more requests than this in a minute, a count. |
| `SWW_ANOMALY_ASN_REQUESTS_PER_HOUR` | `off` | Alert when one AS number makes more requests than this in an hour, a count. |
| `SWW_ANOMALY_ASN_BYTES_PER_MINUTE` | `off` | Alert when one AS number carries more bytes than this in a minute, a size. |
| `SWW_ANOMALY_ASN_BYTES_PER_HOUR` | `off` | Alert when one AS number carries more bytes than this in an hour, a size. |
| `SWW_ANOMALY_TOTAL_REQUESTS_PER_MINUTE` | `off` | Alert when the whole service gets more requests than this in a minute, a count. |
| `SWW_ANOMALY_TOTAL_REQUESTS_PER_HOUR` | `off` | Alert when the whole service gets more requests than this in an hour, a count. |
| `SWW_ANOMALY_TOTAL_BYTES_PER_MINUTE` | `off` | Alert when the whole service carries more bytes than this in a minute, a size. |
| `SWW_ANOMALY_TOTAL_BYTES_PER_HOUR` | `off` | Alert when the whole service carries more bytes than this in an hour, a size. |
| `SWW_WATCH_NETS` | empty | Named netblocks the `SWW_WATCH_` thresholds count each as a whole, such as `office=203.0.113.0/24,scraper-x=198.51.100.0/22`. |
| `SWW_WATCH_REQUESTS_PER_MINUTE` | `off` | Alert when a watched netblock makes more requests than this in a minute, a count. |
| `SWW_WATCH_REQUESTS_PER_HOUR` | `off` | Alert when a watched netblock makes more requests than this in an hour, a count. |
| `SWW_WATCH_BYTES_PER_MINUTE` | `off` | Alert when a watched netblock carries more bytes than this in a minute, a size. |
| `SWW_WATCH_BYTES_PER_HOUR` | `off` | Alert when a watched netblock carries more bytes than this in an hour, a size. |
[`docs/settings.md`](docs/settings.md) gives the values each setting takes in
full, and the limits that are fixed rather than settings.
@@ -554,11 +556,15 @@ status for a size or time limit, such as `413` for a body too large.
headers of every request, and no body unless `SWW_WAF_BODY_LIMIT` is set. In
front of a code forge, bodies carry what people write and publish, which the
rules take for attacks.
- `smallwebwaf` changes the Core Rule Set in eight ways so that it lets ordinary
- `smallwebwaf` changes the Core Rule Set in six ways so that it lets ordinary
requests to a code forge through, such as git over HTTP and sign-in through
Git Credential Manager. On gitea's own paths, its searches, file names and
branch names get through too. No setting undoes the changes; "Attack
detection" in [`SPEC.md`](SPEC.md) lists them.
Git Credential Manager. No setting undoes the changes; "Attack detection" in
[`SPEC.md`](SPEC.md) lists them.
- Each supported app also has its own fixes, which let its ordinary requests
through. gitea's let its searches, file names and branch names through.
`SWW_APPS` names the apps each hostname serves. A hostname gets only its own
apps' fixes, and a hostname it does not list gets none. Unset, every app's
fixes apply to every hostname.
- `SWW_CORE_RULE_SET_EXCLUSIONS_FILE` switches single rules off for an app's own
fields or paths.
- Rule files are plain text, one rule to a line, edited by hand and read again
@@ -581,10 +587,10 @@ is set aside as `<name>.bad`, and never stops the running process (see
come from Ubuntu's archive, and nixpkgs is fixed at one release. An app's
`Dockerfile` installs a package with `nix-env -iA nixpkgs.<name>` and gets the
same package each time it is built (see [`docs/image.md`](docs/image.md)).
- runit, a service supervisor, runs `smallwebwaf` as the `sww` user (uid and
gid 65532) and starts it again when it exits. The `run` script of
`discriminator` gives the state directory to the `sww` user at each start, so
a volume needs no change of owner.
- runit, a service supervisor, runs `sww` as the `sww` user (uid and gid 65532)
and starts it again when it exits. The `run` script of `discriminator` gives
the state directory to the `sww` user at each start, so a volume needs no
change of owner.
- `rproxy` and `discriminator` use no token between them. `discriminator`'s own
endpoints, under `/_sww/`, are for your admin tools and your metrics
collector, at its own address on the private network; nothing routes the
SPEC.md
+76 -51
View File
@@ -1,7 +1,7 @@
# smallwebwaf specification
`smallwebwaf` is a web application firewall for self-hosted apps. It is one
binary, and two of its commands do the work:
binary, `sww`, and two of its commands do the work:
- `sww rproxy` is a reverse proxy between traefik and one app.
- `sww discriminator` decides what happens to each request, for many sites.
@@ -81,8 +81,8 @@ to them.
of bans is full.
- `internal/rules`: reads the rule files at start and again when they
change, and tells which rules a request matches.
- `internal/waf`: the Core Rule Set, with the eight changes listed under
"Attack detection", as Coraza directives.
- `internal/waf`: the Core Rule Set, with the six changes and the apps'
fixes listed under "Attack detection", as Coraza directives.
- `internal/lookup`: looks clients up through GeoJS or in the lookup
database.
- `internal/reputation`: fetches the lists, asks the DNS blocklists and
@@ -326,7 +326,8 @@ Conventions:
the value itself would be. Setting both forms stops the start, and so does
naming a file that cannot be read. `SWW_LOG_REMOTE_TLS_CA_FILE` and
`SWW_CORE_RULE_SET_EXCLUSIONS_FILE` already hold a file name, so they have no
`_FILE` form. No `SWRP_` setting has one, since `rproxy` never touches disk.
`_FILE` form. `SWW_COMMAND` cannot be given as a file. No `SWRP_` setting has
one, since `rproxy` never touches disk.
- Settings, files included, are read once at start. Changing one means
restarting the container. The files `discriminator` watches while it runs are
its state files, its rule files and the lookup database.
@@ -583,9 +584,9 @@ files, the limits and the bans still apply to the client that sends it.
- `SWW_CORE_RULE_SET_EXCLUSIONS_FILE` names a file of exclusions, written as
Coraza directives. An exclusion switches one rule off for some fields or paths
only, where `SWW_WAF_DISABLED_RULES` switches it off everywhere. The file
holds an app's own exclusions; the eighth change below holds gitea's.
- `discriminator` loads the file after `sww`'s own setup rules and before
the Core Rule Set's rules. The Core Rule Set loads its own
holds an app's own exclusions; gitea's fixes below hold gitea's.
- `discriminator` loads the file after `smallwebwaf`'s own setup rules and
before the Core Rule Set's rules. The Core Rule Set loads its own
`REQUEST-900-EXCLUSION-RULES-BEFORE-CRS.conf` at the same point.
- So the file holds only `SecAction` and `SecRule` lines that exclude with
`ctl:ruleRemoveTargetById` or `ctl:ruleRemoveById`. These run with each
@@ -595,7 +596,8 @@ files, the limits and the bans still apply to the client that sends it.
- The start stops on a file that cannot be read or does not parse, whatever
`SWW_WAF_MODE` is.
- It stops too on a file that names a number from 900000 to 900999, the ids
of `sww`'s own rules, alone or in a range. Comment lines are not checked.
of `smallwebwaf`'s own rules, alone or in a range. Comment lines are not
checked.
- It stops too on a directive that removes or changes rules as the file
loads, such as `SecRuleRemoveById`, since none of the Core Rule Set's
rules is loaded yet.
@@ -628,7 +630,7 @@ files, the limits and the bans still apply to the client that sends it.
scanner from an ordinary client. In front of a code forge, registry and git
clients get `404` and `401` by design, hundreds of times a minute.
`smallwebwaf` changes the Core Rule Set 4.25.0 in eight ways, since in front of
`smallwebwaf` changes the Core Rule Set 4.25.0 in six ways, since in front of
gitea it would otherwise refuse ordinary requests. The changes hold in front of
every app, and no setting undoes them:
@@ -647,8 +649,52 @@ every app, and no setting undoes them:
and tea, which gitea registers for OAuth sign-in, ask to be sent back to
`http://127.0.0.1` on the user's own machine. The server never fetches that
address.
4. Ten query parameters are not checked against the Core Rule Set's lists of
system files (930120), shell paths (932160) and command names (932260):
4. `Referer` is not checked for a Unix command given without arguments (932340),
for Java starting a process (944110) or for a Java class name (944130).
`Referer` names the page a request comes from, on everything that page loads
and on every link followed from it. The Core Rule Set takes some page
addresses for attacks:
- a search for `env`;
- OpenJDK's `Runtime.java`, whose path holds both `runtime` and `java.`;
- a file named `java.lang.String.md`.
Every request from such a page would be refused. `Referer` keeps the other
rules, except after some gitea searches (gitea's fixes). An app that passes
`Referer` to a shell must check it itself.
5. Responses are not inspected. A raw file from a repository, such as a shell
script, looks to the response rules like source code leaking from the server.
6. The `from` parameter of a container registry's upload path,
`/v2/<image>/blobs/uploads/`, is not checked for command names (932260). When
a push reuses a layer, `from` names the image the layer comes from. An image
such as `owner/python3-app` would have that push refused.
Each supported app also has its own fixes, which let its ordinary requests
through. An app's fixes hold for the hostnames `SWW_APPS` lists the app for:
- `SWW_APPS` holds entries separated by semicolons. Each is a hostname, a colon,
then one or more apps separated by commas, for example
`git.example.com:gitea;code.example.com:gitea`.
- The request's `Host` is matched by exact name, without its port and without
regard to case. There are no wildcards.
- A hostname not listed gets no app's fixes, so every rule checks it in full.
Set empty, `SWW_APPS` lists no hostname.
- Unset, every app's fixes hold for every hostname. An app's fixes then weaken
the check of any other app that serves the same paths or fields.
- Any of these mistakes stops the start:
- an unknown app;
- a hostname that is not a DNS name, such as `*.example.com`;
- a hostname listed twice;
- an app listed twice for one hostname;
- an entry without a colon.
`gitea` is the only app supported. Each app's fixes are in one file, such as
`internal/waf/gitea.conf`, and one entry of `apps` in `internal/waf/waf.go`.
gitea's fixes are:
1. Ten query parameters are not checked against the Core Rule Set's lists of
system files (930120), shell paths (932160) and command names (932260), on
any path:
- `path`, `files`, `skip-to` and `sub_path`;
- `ref`, `sha`, `branch` and `workflow`;
- `artifactName` and `redirect_to`.
@@ -661,41 +707,18 @@ every app, and no setting undoes them:
catch reaches the app, such as the command `|cat /etc/passwd`. Path
traversal, SQL and script injection, and PHP, Java and Node.js code are
still refused there. Other parameters keep all three rules, except on the
gitea paths the eighth change names. An app that uses one of these
parameters as a file on the server, or passes it to a shell, must check the
value itself. A rule file can refuse it instead.
gitea paths the third fix names.
5. Two cookies are left out, and `Referer` keeps fewer rules:
- The Core Rule Set reads the request without the `gitea_flash` and
`redirect_to` cookies. gitea puts a message naming what was just done into
`gitea_flash`. It puts into `redirect_to` the page to return to after
signing in. The Core Rule Set takes file names in them, such as
`package.json`, for attacks. A browser sends such a cookie with every
request until gitea replaces it. gitea cannot replace it while those
requests are refused, so one refusal would keep the browser out of the
whole site. gitea shows the message with any script removed and returns
only to its own pages. Every other cookie is read in full. An app that
reads a cookie of either name must check it itself.
- `Referer` is not checked for a Unix command given without arguments
(932340), for Java starting a process (944110) or for a Java class name
(944130). `Referer` names the page a request comes from, on everything
that page loads and on every link followed from it. The Core Rule Set
takes some page addresses for attacks:
- a search for `env`;
- OpenJDK's `Runtime.java`, whose path holds both `runtime` and `java.`;
- a file named `java.lang.String.md`.
Every request from such a page would be refused. `Referer` keeps the
other rules, except after some gitea searches (the eighth change). An
app that passes `Referer` to a shell must check it itself.
6. Responses are not inspected. A raw file from a repository, such as a shell
script, looks to the response rules like source code leaking from the server.
7. The `from` parameter of a container registry's upload path,
`/v2/<image>/blobs/uploads/`, is not checked for command names (932260). When
a push reuses a layer, `from` names the image the layer comes from. An image
such as `owner/python3-app` would have that push refused.
8. On gitea's paths, some fields skip the rules that refused ordinary gitea
2. The Core Rule Set reads the request without the `gitea_flash` and
`redirect_to` cookies. gitea puts a message naming what was just done into
`gitea_flash`. It puts into `redirect_to` the page to return to after signing
in. The Core Rule Set takes file names in them, such as `package.json`, for
attacks. A browser sends such a cookie with every request until gitea
replaces it. gitea cannot replace it while those requests are refused, so one
refusal would keep the browser out of the whole site. gitea shows the message
with any script removed and returns only to its own pages. Every other cookie
is read in full.
3. On gitea's paths, some fields skip the rules that refused ordinary gitea
requests there. They are the fields where gitea sends a search, a file name
or a branch name. `internal/waf/gitea.conf` lists each rule and the request
it refused. The fields are:
@@ -713,8 +736,7 @@ every app, and no setting undoes them:
- packages.
A user's or an organisation's page is any path of one segment, so on
every such path, on any app, `q` skips these three rules, for example on
`/search`.
every such path `q` skips these three rules, for example on `/search`.
Some of these searches also skip the rule for Java class names (944130),
which refused `org.apache.commons.logging`.
@@ -752,11 +774,14 @@ every app, and no setting undoes them:
`actions/upload-artifact@v3` (920450).
Elsewhere these fields keep every rule. The paths are those of gitea at the
site root. An app other than gitea that serves one of them must check these
fields itself.
site root.
The parameter and cookie names in these changes are matched without regard to
case, as Coraza matches them.
On a hostname that gets gitea's fixes, an app other than gitea must check these
fields and cookies itself. Listing each hostname's own apps in `SWW_APPS` keeps
the full check for the others.
The parameter names in these changes and fixes are matched without regard to
case, and the cookie names exactly.
### Ban lengths, response and scope
cmd/sww/main.go
+5 -5
View File
@@ -1,8 +1,8 @@
// Command sww is a web application firewall. `sww rproxy` is
// the reverse proxy in front of one app, which asks discriminator about each request.
// `sww discriminator` decides, for many sites, and keeps what lasts.
// `sww healthcheck` is the container's health check. Everything it does
// is in internal/sww.
// Command sww is a web application firewall. `sww rproxy` is the reverse
// proxy in front of one app, which asks discriminator about each request.
// `sww discriminator` decides, for many sites, and keeps what lasts. `sww
// healthcheck` is the container's health check. Everything it does is in
// internal/sww.
package main
import (
docs/settings.md
+18
View File
@@ -198,6 +198,24 @@ between the two (see "The image's command" below).
a range. So does a directive that removes or changes rules as the file loads,
such as `SecRuleRemoveById`, since none of the Core Rule Set's rules is loaded
yet. It has no `_FILE` form.
- `SWW_APPS` (default unset): the apps each hostname serves. A request gets the
fixes of its hostname's apps only (see "Attack detection" in
[`SPEC.md`](../SPEC.md)).
- Entries are separated by semicolons. Each is a hostname, a colon, then one
or more apps separated by commas, for example
`git.example.com:gitea;code.example.com:gitea`.
- `gitea` is the only app supported.
- The request's `Host` is matched by exact name, without its port and
without regard to case. There are no wildcards.
- A hostname not listed gets no app's fixes, so every rule checks it in
full. Set empty, it lists no hostname.
- Unset, every app's fixes apply to every hostname.
- Any of these mistakes stops the start:
- an unknown app;
- a hostname that is not a DNS name, such as `*.example.com`;
- a hostname listed twice;
- an app listed twice for one hostname;
- an entry without a colon.
- `SWW_ERROR_BURST_THRESHOLD` (default `30`): the most refusals of one client in
a minute (see "Attack detection" in `SPEC.md`). A count or `off`.
internal/config/config.go
+91 -1
View File
@@ -29,6 +29,7 @@ import (
"sneak.berlin/go/smallwebwaf/internal/alerts"
"sneak.berlin/go/smallwebwaf/internal/anomaly"
"sneak.berlin/go/smallwebwaf/internal/remotelog"
"sneak.berlin/go/smallwebwaf/internal/waf"
)
// Config is the settings of `sww discriminator`. A time or size limit of
@@ -230,6 +231,11 @@ type Config struct {
WAFExemptPaths []string
WAFBodyLimit int64
CoreRuleSetExclusionsFile string
// Apps are the names of the apps each hostname serves, by hostname in
// lowercase (SWW_APPS): a request gets only its hostname's apps' fixes
// to the Core Rule Set. Apps is nil while SWW_APPS is unset, and every
// request gets every app's fixes.
Apps map[string][]string
// TrapPaths are the paths a request for which is a clear sign of
// attack (SWW_TRAP_PATHS), each starting with / and without a ?.
TrapPaths []string
@@ -398,6 +404,10 @@ var (
"is not a path prefix starting with /, such as /assets/")
errNotTrapPath = errors.New(
"is not a path starting with / and without a ?, such as /wp-login.php")
errNotAppsEntry = errors.New(
"is not a hostname, : and a list of apps, such as git.example.com:gitea")
errNotHostname = errors.New("is not a DNS name such as git.example.com")
errNotApp = errors.New("is not an app sww has fixes for; the apps are")
errNotWAFMode = errors.New("is not off, detect or block")
errNotParanoiaLevel = errors.New("is not a paranoia level, from 1 to 4")
errNotRuleID = errors.New(
@@ -530,6 +540,7 @@ func FromEnvironment(lookupEnv func(string) (string, bool)) (*Config, error) {
WAFBodyLimit: env.wafBodyLimit("SWW_WAF_BODY_LIMIT", off),
CoreRuleSetExclusionsFile: env.filePath(
"SWW_CORE_RULE_SET_EXCLUSIONS_FILE"),
Apps: env.apps("SWW_APPS"),
TrapPaths: env.trapPaths("SWW_TRAP_PATHS"),
ErrorBurstThreshold: env.count("SWW_ERROR_BURST_THRESHOLD", "30"),
LogRemoteURL: env.logRemoteURL("SWW_LOG_REMOTE_URL"),
@@ -780,6 +791,25 @@ func (e *environment) pathPrefixes(name, defaultValue string) []string {
return prefixes
}
// apps reads the setting that is the apps each hostname serves. It is nil
// while the setting is unset, and logged as null, unlike a setting set
// empty.
func (e *environment) apps(name string) map[string][]string {
value, set := e.lookup(name)
if !set {
e.settings = append(e.settings, slog.Any(name, nil))
return nil
}
e.settings = append(e.settings, slog.String(name, value))
apps, err := parseApps(value)
e.check(name, err)
return apps
}
// trapPaths reads the setting that is the list of trap paths. It is empty
// by default.
func (e *environment) trapPaths(name string) []string {
@@ -1646,6 +1676,65 @@ func parseTrapPaths(value string) ([]string, error) {
return paths, nil
}
// parseApps reads the apps each hostname serves: entries separated by
// semicolons, each a hostname, a colon, and a comma-separated list of the
// names waf.AppNames returns, such as
// git.example.com:gitea;cloud.example.com:nextcloud,wordpress. Each
// hostname is a DNS name, without a wildcard. It returns them by hostname
// in lowercase, since a hostname is matched without regard to case. An
// empty value lists no hostname.
func parseApps(value string) (map[string][]string, error) {
apps := map[string][]string{}
if strings.TrimSpace(value) == "" {
return apps, nil
}
for entry := range strings.SplitSeq(value, ";") {
hostname, list, found := strings.Cut(entry, ":")
if !found {
return nil, fmt.Errorf("%q %w", entry, errNotAppsEntry)
}
hostname = strings.ToLower(strings.TrimSpace(hostname))
if hostname == "" {
return nil, fmt.Errorf("%q %w", entry, errNotAppsEntry)
}
if !isZone(hostname) {
return nil, fmt.Errorf("%q %w", hostname, errNotHostname)
}
if _, listed := apps[hostname]; listed {
return nil, fmt.Errorf("%q %w", hostname, errListedTwice)
}
names, err := parseList(list)
if err != nil {
return nil, err
}
if len(names) == 0 {
return nil, fmt.Errorf("%q %w", entry, errNotAppsEntry)
}
for i, name := range names {
if !slices.Contains(waf.AppNames(), name) {
return nil, fmt.Errorf("%q %w %s", name, errNotApp,
strings.Join(waf.AppNames(), ", "))
}
if slices.Contains(names[:i], name) {
return nil, fmt.Errorf("%q %w", name, errListedTwice)
}
}
apps[hostname] = names
}
return apps, nil
}
// parseRuleIDs reads a comma-separated list of the ids of Core Rule Set
// rules, each a whole number above zero and outside firstSetupRuleID to
// lastSetupRuleID.
@@ -2072,7 +2161,8 @@ func MaskZoneKey(zone string) string {
return masked + "." + rest
}
// isZone reports whether each label of zone is as parseZones takes it.
// isZone reports whether each label of zone is as parseZones takes it. It
// also checks the hostnames of SWW_APPS, which are DNS names too.
func isZone(zone string) bool {
for label := range strings.SplitSeq(zone, ".") {
badChar := strings.ContainsFunc(label, func(char rune) bool {
internal/config/config_test.go
+88
View File
@@ -88,6 +88,7 @@ const (
wafExemptPaths = "SWW_WAF_EXEMPT_PATHS"
wafBodyLimit = "SWW_WAF_BODY_LIMIT"
exclusionsFile = "SWW_CORE_RULE_SET_EXCLUSIONS_FILE"
apps = "SWW_APPS"
trapPaths = "SWW_TRAP_PATHS"
errorBurstThreshold = "SWW_ERROR_BURST_THRESHOLD"
logRemoteURL = "SWW_LOG_REMOTE_URL"
@@ -576,6 +577,92 @@ func TestCoreRuleSetSettings(t *testing.T) {
}
}
func TestApps(t *testing.T) {
t.Parallel()
for _, tc := range []struct {
env environment
want map[string][]string
}{
{environment{}, nil},
{environment{apps: ""}, map[string][]string{}},
{
environment{apps: "Git.Example.com:gitea; cloud.example.com : gitea "},
map[string][]string{
"git.example.com": {"gitea"}, "cloud.example.com": {"gitea"},
},
},
} {
cfg := fromEnvironment(t, tc.env)
if !reflect.DeepEqual(cfg.Apps, tc.want) {
t.Errorf("%v gave %#v, want %#v", tc.env, cfg.Apps, tc.want)
}
}
}
// Unset and set empty, SWW_APPS has opposite effects, so it logs differently.
func TestUnsetAndEmptyAppsAreLoggedDifferently(t *testing.T) {
t.Parallel()
for _, tc := range []struct {
env environment
want string
}{
{environment{}, `"` + apps + `":null`},
{environment{apps: ""}, `"` + apps + `":""`},
} {
var out bytes.Buffer
slog.New(slog.NewJSONHandler(&out, nil)).
Info("starting", "settings", fromEnvironment(t, tc.env))
if !strings.Contains(out.String(), tc.want) {
t.Errorf("%v logged %s, want %s in it", tc.env, out.String(), tc.want)
}
}
}
func TestInvalidAppsStopsTheStart(t *testing.T) {
t.Parallel()
const (
notEntry = " is not a hostname, : and a list of apps, " +
"such as git.example.com:gitea"
notHostname = " is not a DNS name such as git.example.com"
)
for _, tc := range []struct{ value, want string }{
{"git.example.com:gitea;blog.example.com", `"blog.example.com"` + notEntry},
{"git.example.com:gitea;", `""` + notEntry},
{":gitea", `":gitea"` + notEntry},
{"git.example.com:", `"git.example.com:"` + notEntry},
{"*.example.com:gitea", `"*.example.com"` + notHostname},
{"git.example.com/:gitea", `"git.example.com/"` + notHostname},
{"git example.com:gitea", `"git example.com"` + notHostname},
{
"git.example.com:gitea,nextcloud",
`"nextcloud" is not an app sww has fixes for; the apps are gitea`,
},
{
"git.example.com:gitea;GIT.example.com:gitea",
`"git.example.com" is listed twice`,
},
{"git.example.com:gitea,gitea", `"gitea" is listed twice`},
{"git.example.com:gitea,", `"gitea," has an empty item in its list`},
} {
t.Run(tc.value, func(t *testing.T) {
t.Parallel()
_, err := config.FromEnvironment(environment{apps: tc.value}.lookupEnv)
want := apps + ": " + tc.want
if err == nil || err.Error() != want {
t.Errorf("error %v, want %s", err, want)
}
})
}
}
func TestWAFBodyLimitOf64K(t *testing.T) {
t.Parallel()
@@ -2332,6 +2419,7 @@ func TestLogsEachSettingWithItsValue(t *testing.T) {
wafExemptPaths: "",
wafBodyLimit: off,
exclusionsFile: "",
apps: "", // logged as null, which decodes as ""
trapPaths: "",
errorBurstThreshold: "30",
logRemoteURL: "",
internal/discriminator/coreruleset_test.go
+23
View File
@@ -10,6 +10,7 @@ import (
"testing"
"sneak.berlin/go/smallwebwaf/internal/alerts"
"sneak.berlin/go/smallwebwaf/internal/discriminator"
"sneak.berlin/go/smallwebwaf/internal/ratelimit"
"sneak.berlin/go/smallwebwaf/internal/requestlog"
)
@@ -21,6 +22,7 @@ const (
wafDisabledRules = "SWW_WAF_DISABLED_RULES"
wafExemptPaths = "SWW_WAF_EXEMPT_PATHS"
wafBodyLimit = "SWW_WAF_BODY_LIMIT"
apps = "SWW_APPS"
block = "block"
detect = "detect"
)
@@ -237,6 +239,27 @@ func TestDisabledRulesSwitchOffWhatGiteaWouldBeRefused(t *testing.T) {
}
}
func TestGiteasFixesApplyOnlyToAHostnameThatServesGitea(t *testing.T) {
t.Parallel()
// Only gitea's fixes let a file name through in path, a parameter
// gitea sends file names in.
const fileName = "/?path=.gitignore"
s := startDiscriminator(t, "", map[string]string{
wafMode: block, apps: siteA + ":gitea",
})
wantDisposition(t, do(t, s.question(siteA, client, fileName)),
http.StatusOK, discriminator.DispositionAllow)
wantDisposition(t, do(t, s.question(siteB, client, fileName)),
http.StatusForbidden, discriminator.DispositionDeny)
lines := s.out.requestLines(t, 2)
wantLine(t, lines[0], http.StatusOK, requestlog.ActionForward)
wantLine(t, lines[1], http.StatusForbidden, requestlog.ActionWAFBlocked)
}
func TestAttackInAFormBodyIsRefusedOnlyWhileBodiesAreRead(t *testing.T) {
t.Parallel()
internal/discriminator/discriminator.go
+3 -4
View File
@@ -306,10 +306,9 @@ func (h *handler) refuseQuestion(w http.ResponseWriter, reason string) {
// asTheVisitorSentIt returns a copy of r, a question, as the checks and the
// log line are to see it: without the headers rproxy adds for discriminator,
// with
// body, which has been read of r, and with the length the visitor announced,
// as -1 when it announced none. The question's own length covers only the part
// of the body it carries.
// with body, which has been read of r, and with the length the visitor
// announced, as -1 when it announced none. The question's own length covers
// only the part of the body it carries.
func asTheVisitorSentIt(r *http.Request, body []byte) *http.Request {
sent := r.Clone(r.Context())
announced := sent.Header.Get(ContentLengthHeader)
internal/discriminator/proxy.go
+3 -1
View File
@@ -210,7 +210,8 @@ func newReputation(
// NewCoreRuleSet returns the Core Rule Set at SWW_WAF_PARANOIA_LEVEL,
// without the rules SWW_WAF_DISABLED_RULES switches off, reading bodies
// up to SWW_WAF_BODY_LIMIT, with the exclusions in
// SWW_CORE_RULE_SET_EXCLUSIONS_FILE, or nil while SWW_WAF_MODE is off. It
// SWW_CORE_RULE_SET_EXCLUSIONS_FILE and the fixes of the apps in SWW_APPS,
// or nil while SWW_WAF_MODE is off. It
// reads at most QuestionBodyMaxBytes less one byte: a question's body of
// QuestionBodyMaxBytes may be cut short, and the Core Rule Set does not read a
// JSON or XML body over its limit. An exclusions file that waf.New refuses is
@@ -225,6 +226,7 @@ func NewCoreRuleSet(cfg *config.Config) (*waf.CoreRuleSet, error) {
ParanoiaLevel: cfg.WAFParanoiaLevel, DisabledRules: cfg.WAFDisabledRules,
BodyLimit: min(cfg.WAFBodyLimit, QuestionBodyMaxBytes-1),
ExclusionsFile: cfg.CoreRuleSetExclusionsFile,
Apps: cfg.Apps,
})
if err != nil {
return nil, fmt.Errorf("SWW_CORE_RULE_SET_EXCLUSIONS_FILE: %w", err)
internal/discriminator/proxy_test.go
+3 -3
View File
@@ -391,9 +391,9 @@ func startRProxy(
}
// newDiscriminator makes discriminator's server, without starting it, and
// returns it, what
// it writes, and the queue of the alerts it raises, as the settings in env make
// it. No alert is sent from the queue: they wait in it, for the test to look at.
// returns it, what it writes, and the queue of the alerts it raises, as the
// settings in env make it. No alert is sent from the queue: they wait in it,
// for the test to look at.
// With no geojsURL, there is no stand-in for GeoJS to look clients up at, and
// SWW_LOOKUP_SOURCE is off unless env sets it. While it is file, the lookup
// database SWW_LOOKUP_DB_PATH names is read. Clients are checked with AbuseIPDB
internal/rproxy/rproxy.go
+3 -4
View File
@@ -146,10 +146,9 @@ func newTransport() *http.Transport {
}
// newDiscriminatorTransport returns what carries questions and reports to
// discriminator.
// It speaks HTTP/1.1 only. Go's HTTP/2 client refuses to send a visitor's Upgrade
// header, or a Connection header other than close or keep-alive, and that would
// read as discriminator giving no answer.
// discriminator. It speaks HTTP/1.1 only. Go's HTTP/2 client refuses to send
// a visitor's Upgrade header, or a Connection header other than close or
// keep-alive, and that would read as discriminator giving no answer.
func newDiscriminatorTransport() *http.Transport {
transport := newTransport()
transport.Protocols = new(http.Protocols)
internal/rproxy/rproxy_test.go
+4 -5
View File
@@ -268,8 +268,8 @@ func (s *Discriminator) question(t *testing.T) question {
}
// startDiscriminatorAnsweringReports starts a stand-in for discriminator that
// answers each
// question as answer does and each report as report does, and returns its URL.
// answers each question as answer does and each report as report does, and
// returns its URL.
func startDiscriminatorAnsweringReports(
t *testing.T, answer, report http.HandlerFunc,
) string {
@@ -1033,9 +1033,8 @@ func TestAnAnswerOf1MiBGoesToTheVisitor(t *testing.T) {
}
// startDiscriminatorWriting starts a stand-in for discriminator that reads
// each question and
// answers it with text, as it is, and returns its URL. It can send what Go's
// server would not.
// each question and answers it with text, as it is, and returns its URL. It
// can send what Go's server would not.
func startDiscriminatorWriting(t *testing.T, text string) string {
t.Helper()
internal/waf/gitea.conf
+52 -7
View File
@@ -1,8 +1,51 @@
# The eighth change: on gitea's paths, some fields skip the rules that refused
# ordinary gitea requests there. They are the fields where gitea sends a search,
# a file name or a branch name. Each exclusion runs with the request, before the
# rules it switches off, those of phase 1 included, so this file is loaded before
# the Core Rule Set's rules. Each comment names a request the rule refused.
# gitea's fixes: some fields skip the rules that refused ordinary gitea requests.
# They are the fields where gitea sends a search, a file name or a branch name.
# Each exclusion runs with the request, before the rules it switches off, those
# of phase 1 included, so this file is loaded before the Core Rule Set's rules.
# Each comment names a request the rule refused.
# A request whose hostname SWW_APPS does not list gitea for skips every rule
# below. Inspect sets tx.app_gitea on the others.
SecRule &TX:app_gitea "@eq 0" \
"id:900590,phase:1,pass,nolog,skipAfter:END_GITEA"
# The query parameters in which gitea sends names within a repository or its
# own records, or a page of its own site, are not checked against the lists of
# system files, shell paths and command names, on any path:
# 930120: .gitignore
# 932160: bin/docker-entrypoint
# 932260: docker-build
SecAction "id:900591,phase:1,pass,nolog,\
ctl:ruleRemoveTargetById=930120;ARGS:path,\
ctl:ruleRemoveTargetById=930120;ARGS:files,\
ctl:ruleRemoveTargetById=930120;ARGS:skip-to,\
ctl:ruleRemoveTargetById=930120;ARGS:sub_path,\
ctl:ruleRemoveTargetById=930120;ARGS:ref,\
ctl:ruleRemoveTargetById=930120;ARGS:sha,\
ctl:ruleRemoveTargetById=930120;ARGS:branch,\
ctl:ruleRemoveTargetById=930120;ARGS:workflow,\
ctl:ruleRemoveTargetById=930120;ARGS:artifactName,\
ctl:ruleRemoveTargetById=930120;ARGS:redirect_to,\
ctl:ruleRemoveTargetById=932160;ARGS:path,\
ctl:ruleRemoveTargetById=932160;ARGS:files,\
ctl:ruleRemoveTargetById=932160;ARGS:skip-to,\
ctl:ruleRemoveTargetById=932160;ARGS:sub_path,\
ctl:ruleRemoveTargetById=932160;ARGS:ref,\
ctl:ruleRemoveTargetById=932160;ARGS:sha,\
ctl:ruleRemoveTargetById=932160;ARGS:branch,\
ctl:ruleRemoveTargetById=932160;ARGS:workflow,\
ctl:ruleRemoveTargetById=932160;ARGS:artifactName,\
ctl:ruleRemoveTargetById=932160;ARGS:redirect_to,\
ctl:ruleRemoveTargetById=932260;ARGS:path,\
ctl:ruleRemoveTargetById=932260;ARGS:files,\
ctl:ruleRemoveTargetById=932260;ARGS:skip-to,\
ctl:ruleRemoveTargetById=932260;ARGS:sub_path,\
ctl:ruleRemoveTargetById=932260;ARGS:ref,\
ctl:ruleRemoveTargetById=932260;ARGS:sha,\
ctl:ruleRemoveTargetById=932260;ARGS:branch,\
ctl:ruleRemoveTargetById=932260;ARGS:workflow,\
ctl:ruleRemoveTargetById=932260;ARGS:artifactName,\
ctl:ruleRemoveTargetById=932260;ARGS:redirect_to"
# gitea's searches of code, of issues and pull requests, and of commits send the
# text searched for in q, which skips these rules there:
@@ -155,8 +198,8 @@ SecRule REQUEST_FILENAME \
# 942140: information_schema.sql
# 944110: java/lang/Runtime.java
# 944130: java.lang.String.md
# Each request skips the rules that refused it. The fourth change already has
# path and redirect_to skip 930120, 932160 and 932260 on every path.
# Each request skips the rules that refused it. Rule 900591 already has path and
# redirect_to skip 930120, 932160 and 932260 on every path.
# A file's commit graph, in file.
SecRule REQUEST_FILENAME "@rx ^/[^/]+/[^/]+/graph$" \
@@ -281,3 +324,5 @@ SecRule REQUEST_FILENAME \
"@rx ^/api/actions_pipeline/_apis/pipelines/workflows/[0-9]+/artifacts/[^/]+/upload$" \
"id:900640,phase:1,pass,nolog,\
ctl:ruleRemoveTargetById=920450;REQUEST_HEADERS_NAMES:Content-Range"
SecMarker END_GITEA
internal/waf/waf.go
+101 -57
View File
@@ -1,9 +1,9 @@
// Package waf runs the OWASP Core Rule Set 4.25.0, through Coraza, on the
// method, the URL with its query and the headers of a request, and on its
// body while SWW_WAF_BODY_LIMIT is set, with the eight changes sww
// makes to it and the exclusions in SWW_CORE_RULE_SET_EXCLUSIONS_FILE, as
// "Attack detection" under "Settings" in SPEC.md describes them. It reads no
// response.
// body while SWW_WAF_BODY_LIMIT is set, with the six changes sww
// makes to it, the fixes for the apps SWW_APPS names, and the exclusions in
// SWW_CORE_RULE_SET_EXCLUSIONS_FILE, as "Attack detection" under "Settings"
// in SPEC.md describes them. It reads no response.
//
// sww writes only to its state directory, so Coraza is built with
// its no_fs_access tag, as the Dockerfile and script/build build it: of a
@@ -16,6 +16,8 @@ import (
"errors"
"fmt"
"io"
"maps"
"net"
"net/http"
"net/netip"
"os"
@@ -32,8 +34,8 @@ import (
// directives are the Core Rule Set as sww runs it, with the
// paranoia level for %d, bodyDirectives for the first %s while
// SWW_WAF_BODY_LIMIT is set, the exclusions file for the second, and
// giteaExclusions for the third.
// SWW_WAF_BODY_LIMIT is set, the exclusions file for the second, and the
// directives of every app in apps for the third.
// Each rule sww adds has an id from 900000 to 900999, the ids the
// Core Rule Set keeps for the rules that set it up, which
// SWW_WAF_DISABLED_RULES and the exclusions file refuse, so that no
@@ -81,44 +83,28 @@ SecRule ARGUMENTS_LIMIT_REACHED "@eq 1" "id:900300,phase:2,pass,\
# before the rules of phase 1 too.
%s
# The eighth change comes before the rules for the same reason.
# The apps' fixes come before the rules for the same reason.
%s
# The sixth: only the rules for requests are loaded, and no response is
# The fifth: only the rules for requests are loaded, and no response is
# inspected.
Include @owasp_crs/REQUEST-*.conf
# The third: redirect_uri is not checked for a URL naming an IP address or
# localhost. Coraza matches a parameter name here, and in the fourth,
# without regard to case. ARGS holds the fields of a form data or multipart
# body Coraza reads as well as the query parameters, so a field of one of
# these names is left out too.
# localhost. Coraza matches a parameter name here without regard to case.
# ARGS holds the fields of a form data or multipart body Coraza reads as
# well as the query parameters, so a field of this name is left out too.
SecRuleUpdateTargetById 931100 "!ARGS:redirect_uri"
SecRuleUpdateTargetById 934110 "!ARGS:redirect_uri"
# The fourth: the query parameters in which gitea sends names within a
# repository or its own records, or a page of its own site, are not
# checked against the lists of system files, shell paths and command
# names. Coraza takes one rule id per directive.
SecRuleUpdateTargetById 930120 "!ARGS:path|!ARGS:files|!ARGS:skip-to|\
!ARGS:sub_path|!ARGS:ref|!ARGS:sha|!ARGS:branch|!ARGS:workflow|\
!ARGS:artifactName|!ARGS:redirect_to"
SecRuleUpdateTargetById 932160 "!ARGS:path|!ARGS:files|!ARGS:skip-to|\
!ARGS:sub_path|!ARGS:ref|!ARGS:sha|!ARGS:branch|!ARGS:workflow|\
!ARGS:artifactName|!ARGS:redirect_to"
SecRuleUpdateTargetById 932260 "!ARGS:path|!ARGS:files|!ARGS:skip-to|\
!ARGS:sub_path|!ARGS:ref|!ARGS:sha|!ARGS:branch|!ARGS:workflow|\
!ARGS:artifactName|!ARGS:redirect_to"
# The fifth, for Referer: it is not checked for a Unix command without
# arguments, for Java starting a process, or for a Java class name. 944130
# refused every page opened from the page of java.lang.String.md. The
# cookies are left out in Inspect.
# The fourth: Referer is not checked for a Unix command without arguments,
# for Java starting a process, or for a Java class name. 944130 refused
# every page opened from the page of java.lang.String.md.
SecRuleUpdateTargetById 932340 "!REQUEST_HEADERS:Referer"
SecRuleUpdateTargetById 944110 "!REQUEST_HEADERS:Referer"
SecRuleUpdateTargetById 944130 "!REQUEST_HEADERS:Referer"
# The seventh: a container image push that reuses a layer names the image
# The sixth: a container image push that reuses a layer names the image
# it takes the layer from in the query parameter from, which is not
# checked for command names. 932260 refused the push of a layer from
# owner/python3-app.
@@ -168,18 +154,36 @@ SecRule MULTIPART_STRICT_ERROR "!@eq 0" "id:900450,phase:2,pass,\
severity:'CRITICAL',setvar:'tx.inbound_anomaly_score_pl1=+5'"
`
// giteaExclusions are the eighth change: the fields of gitea's own
// requests that skip the rules that refused them there, as Coraza
// directives.
//
//go:embed gitea.conf
var giteaExclusions string
// app is an app whose ordinary requests the Core Rule Set would refuse,
// with the fixes that let them pass.
type app struct {
// directives are Coraza exclusions, loaded before the Core Rule Set's
// rules. Their first rule skips the rest unless Inspect sets the
// transaction variable app_ and the app's name, and they end with the
// marker it skips to.
directives string
// cookies are the cookies the Core Rule Set reads a request without.
cookies []string
}
// cookiesNotRead are the cookies the Core Rule Set reads a request
// without, the rest of the fifth change.
//go:embed gitea.conf
var giteaDirectives string
// apps are the apps whose fixes sww has, by the name SWW_APPS gives each.
//
//nolint:gochecknoglobals // a constant cannot be a list
var cookiesNotRead = []string{"gitea_flash", "redirect_to"}
//nolint:gochecknoglobals // a constant cannot be a map
var apps = map[string]app{
"gitea": {
directives: giteaDirectives,
cookies: []string{"gitea_flash", "redirect_to"},
},
}
// AppNames returns the names of the apps whose fixes sww has, in
// alphabetical order.
func AppNames() []string {
return slices.Sorted(maps.Keys(apps))
}
// Params are what New needs.
type Params struct {
@@ -195,6 +199,10 @@ type Params struct {
// Core Rule Set's rules (SWW_CORE_RULE_SET_EXCLUSIONS_FILE), "" while
// there is none.
ExclusionsFile string
// Apps are the names of the apps each hostname serves, by hostname in
// lowercase (SWW_APPS). A request gets the fixes of its hostname's
// apps only, or of every app while Apps is nil.
Apps map[string][]string
}
// The ids of sww's own rules, which an exclusions file may not
@@ -286,13 +294,15 @@ func checkExclusions(exclusions string) error {
type CoreRuleSet struct {
waf coraza.WAF
bodyLimit int64
apps map[string][]string
}
// New returns the Core Rule Set with the eight changes, at params'
// paranoia level, without the rules it switches off, reading request
// bodies up to params' limit, and with params' exclusions file loaded
// before the Core Rule Set's rules. An exclusions file is an error if it
// cannot be read or does not parse, or if checkExclusions refuses it.
// New returns the Core Rule Set with the six changes and the apps' fixes,
// at params' paranoia level, without the rules it switches off, reading
// request bodies up to params' limit, and with params' exclusions file
// loaded before the Core Rule Set's rules. An exclusions file is an error
// if it cannot be read or does not parse, or if checkExclusions refuses
// it.
func New(params Params) (*CoreRuleSet, error) {
body := ""
if params.BodyLimit > 0 {
@@ -315,8 +325,13 @@ func New(params Params) (*CoreRuleSet, error) {
}
}
var fixes strings.Builder
for _, name := range AppNames() {
fixes.WriteString(apps[name].directives + "\n")
}
text := fmt.Sprintf(directives, params.ParanoiaLevel, body, exclusions,
giteaExclusions)
fixes.String())
if len(params.DisabledRules) > 0 {
ids := make([]string, len(params.DisabledRules))
@@ -334,7 +349,7 @@ func New(params Params) (*CoreRuleSet, error) {
return nil, fmt.Errorf("load the Core Rule Set: %w", err)
}
return &CoreRuleSet{waf: waf, bodyLimit: params.BodyLimit}, nil
return &CoreRuleSet{waf: waf, bodyLimit: params.BodyLimit, apps: params.Apps}, nil
}
// Result is what the Core Rule Set found in a request.
@@ -346,11 +361,12 @@ type Result struct {
Score int
}
// Inspect runs the Core Rule Set on r, a request from client: on its
// method, its URL with the query, and its headers, the Cookie header
// without the cookies in cookiesNotRead, and on body, r's body as the
// caller has it, as readBody reads it. It returns what it found, what it
// read of body, and the error that ended the reading early, if one did.
// Inspect runs the Core Rule Set on r, a request from client, with the
// fixes of the apps appsFor names for r's hostname: on its method, its URL
// with the query, and its headers, the Cookie header without those apps'
// cookies, and on body, r's body as the caller has it, as readBody reads
// it. It returns what it found, what it read of body, and the error that
// ended the reading early, if one did.
func (c *CoreRuleSet) Inspect(
r *http.Request, client netip.Addr, body io.Reader,
) (Result, []byte, error) {
@@ -358,13 +374,24 @@ func (c *CoreRuleSet) Inspect(
// Closing would remove the files Coraza wrote, and it writes none.
defer func() { _ = tx.Close() }()
// The transaction's variables are set only through Coraza's interface
// for plugins.
state := tx.(plugintypes.TransactionState) //nolint:forcetypeassert // every one is
var cookiesNotRead []string
for _, name := range c.appsFor(r.Host) {
state.Variables().TX().Set("app_"+name, []string{"1"})
cookiesNotRead = append(cookiesNotRead, apps[name].cookies...)
}
tx.ProcessConnection(client.String(), 0, "", 0)
tx.ProcessURI(r.URL.String(), r.Method, r.Proto)
for name, values := range r.Header {
for _, value := range values {
if name == "Cookie" {
value = withoutCookiesNotRead(value)
value = withoutCookies(value, cookiesNotRead)
if value == "" {
continue // it held those cookies alone
}
@@ -457,9 +484,26 @@ func score(tx types.Transaction) int {
return n
}
// withoutCookiesNotRead returns value, a Cookie header's, without the
// cookies in cookiesNotRead.
func withoutCookiesNotRead(value string) string {
// appsFor returns the names of the apps whose fixes a request for host,
// its Host header, gets: every app while SWW_APPS is unset, and otherwise
// those SWW_APPS lists for host's name, without the port and in
// lowercase.
func (c *CoreRuleSet) appsFor(host string) []string {
if c.apps == nil {
return AppNames()
}
hostname, _, err := net.SplitHostPort(host)
if err != nil {
hostname = host // it has no port
}
return c.apps[strings.ToLower(hostname)]
}
// withoutCookies returns value, a Cookie header's, without the cookies
// named in cookiesNotRead.
func withoutCookies(value string, cookiesNotRead []string) string {
var kept []string
for cookie := range strings.SplitSeq(value, ";") {
internal/waf/waf_test.go
+92 -2
View File
@@ -120,8 +120,8 @@ func atDefaults(t *testing.T) *waf.CoreRuleSet {
}
// wantChange checks that crs lets through passes, a gitea request one of
// the eight changes is for, and still finds result in refused, a request
// like it that the change is not for.
// the six changes or gitea's fixes are for, and still finds result in
// refused, a request like it that they are not for.
func wantChange(
t *testing.T, crs *waf.CoreRuleSet, passes, refused request, result waf.Result,
) {
@@ -381,6 +381,96 @@ func TestImagePushThatReusesALayerIsNotCheckedForCommandNames(t *testing.T) {
matched(930120, 932160))
}
// giteaFixed are gitea requests that only gitea's fixes let through, one
// for each kind of fix, each with what the Core Rule Set finds in it
// without them.
//
//nolint:gochecknoglobals // a constant cannot be a list
var giteaFixed = []struct {
request request
result waf.Result
}{
// A search of code, on the path of gitea's search.
{get("/explore/code?q=SELECT%20*%20FROM%20users%20WHERE"), matched(942100)},
// A file name, in a parameter gitea sends names in, on any path.
{get("/?path=.gitignore"), matched(930120)},
// A file name, in a cookie of gitea's.
{
get("/owner/repo", "Cookie: gitea_flash=success%3DFile%2Bpackage.json%2Bdeleted"),
matched(930120),
},
}
// The hostnames of the tests of SWW_APPS: the one that serves gitea, and
// one that serves another app.
const (
giteaHost = "git.example"
otherHost = "blog.example"
)
// withHost returns r sent to host.
func withHost(r request, host string) request {
return request{r.method, r.target, append([]string{"Host: " + host}, r.headers...)}
}
// servingApps returns the Core Rule Set at the defaults, with SWW_APPS
// giving apps.
func servingApps(t *testing.T, apps map[string][]string) *waf.CoreRuleSet {
t.Helper()
crs, err := waf.New(waf.Params{
ParanoiaLevel: 1, DisabledRules: defaultDisabledRules, Apps: apps,
})
if err != nil {
t.Fatalf("load the Core Rule Set: %v", err)
}
return crs
}
func TestAppsUnsetGivesEveryHostnameEveryAppsFixes(t *testing.T) {
t.Parallel()
crs := servingApps(t, nil)
for _, fixed := range giteaFixed {
for _, host := range []string{giteaHost, otherHost} {
wantResult(t, crs, withHost(fixed.request, host), waf.Result{})
}
}
}
func TestListedHostnameGetsItsAppsFixes(t *testing.T) {
t.Parallel()
crs := servingApps(t, map[string][]string{giteaHost: {"gitea"}})
// The hostname is matched without the port and without regard to case.
for _, host := range []string{giteaHost, "GIT.Example:8443"} {
for _, fixed := range giteaFixed {
wantResult(t, crs, withHost(fixed.request, host), waf.Result{})
}
}
}
func TestUnlistedHostnameGetsTheFullCheck(t *testing.T) {
t.Parallel()
for _, apps := range []map[string][]string{
{giteaHost: {"gitea"}},
// SWW_APPS set empty lists no hostname.
{},
} {
crs := servingApps(t, apps)
for _, host := range []string{otherHost, otherHost + ":8443", "git.example.org"} {
for _, fixed := range giteaFixed {
wantResult(t, crs, withHost(fixed.request, host), fixed.result)
}
}
}
}
// withExclusions returns the Core Rule Set at the defaults, with the
// exclusions file at path.
func withExclusions(path string) (*waf.CoreRuleSet, error) {