tlsx hangs indefinitely for some hosts #819
Description
tlsx version:
v1.1.9
Current Behavior:
For long target lists (in our case: Around 30k host/port combinations), tlsx reliably hangs indefinitely after several hours of execution, usually after around 25k targets have finished. Hanging happens even while writing JSONL output lines, cutting off a JSONL line somewhere in the middle.
Expected Behavior:
tlsx should not hang indefinitely.
Steps To Reproduce:
tlsx was started as follows:
~/go/bin/tlsx \
-list /tmp/host_port_combos.txt \
-scan-mode 'auto' \
-ip-version '4' \
-so \
-tls-version \
-cipher \
-hash 'sha256' \
-wildcard-cert \
-probe-status \
-version-enum \
-cipher-enum \
-cipher-type 'all' \
-serial \
-expired \
-self-signed \
-mismatched \
-revoked \
-untrusted \
-resolvers 8.8.8.8,8.8.4.4,1.1.1.1 \
-certificate \
-tls-chain \
-concurrency '300' \
-cipher-concurrency '10' \
-timeout '5' \
-retry '3' \
-disable-update-check \
-output /tmp/tlsx_output.jsonl \
-json \
-no-color
At one point, there is no more progress and even output is no longer written. This is the last line of the output file (/tmp/tlsx_output.jsonl):
{"timestamp":"2025-04-25T09:59:31.489674682Z","host":"xn--<censored>-t6b.<censored>","ip":"<censored>","port":"443","probe_status":true,"tls_version":"tls13","cipher":"TLS_AES_128_GCM_SHA256","self_signed":true,"mismatched":true,"not_before":"2017-01-16T16:04:01Z","not_after":"2027-01-14T16:04:01Z","subject_dn":"emailAddress=root@localhost.localdomain, CN=localhost.localdomain, OU=IT, O=MyCompany, L=Seattle, ST=WA, C=US, emailAddress=root@localhost.localdomain","subject_cn":
Please note that the line ends with an open "subject_cn" key and the JSON object on that line is never closed. The aforementioned line is line 25737 of the output file, so more than 25k targets have been scanned before.
Anything else:
The issue always appears after a long time of execution. Execution of tlsx for the aforementioned approx. 30k targets (aborted/hanging after about 25k targets) started at 2025-04-24T16:50:47+00:00 and the process started hanging at 2025-04-25T10:47:39+0000, so about 18 hours later.
The issue does not seem to depend on the specific target host, as tlsx correctly terminates when only scanning the target host. Also, it always starts hanging indefinitely for a different target, but always after having run for hours and after having already scanned several thousand targets,