There is a case where using this on a network with some (slight) instability or slowness can sometimes fail to detect HTTP headers. Currently, in my testing here, I've seen this range anywhere from 5.7 seconds to 7.8 seconds for a response from getting the headers, so maybe we should consider increasing the time slightly for the header max sleep value. 10 seconds is arbitrary, but still 'short'.
(Feel free to discuss or decline, but I'm hoping we can incorporate this to adapt for slightly slower networks)
s_client's manpage states for -nextprotoneg:
"Empty list of protocols is treated specially and will cause the client
to advertise support for the TLS extension but disconnect just after
reciving ServerHello with a list of server supported protocols."
Consequently, the previous workaround of just quoting an empty variable
is insufficient and the "-nextprotoneg" parameter has to be removed
entirely from the command-line in case of an empty argument.
In other locations where "-nextprotoneg" is used
- its argument cannot be empty ($NPN_PROTOs is initialized to a non-
empty value and set read-only) or
- its argument is intended to be empty (line 3724) or
- the command will not be invoked at all (for-loop parameter, line 3725)
This fixes#467 - again.
Additionally this patch prefers usage of -alpn over -nextprotoneg if the
openssl binary used supports it.
Refactor the while loop so it doesn't use a subshell anymore. Also use
"read -r" to prevent backslash escaping.
```
In testssl.sh line 1193:
app_banners="$app_bannersline"
^-- SC2030: Modification of app_banners is local (to subshell caused by pipeline).
In testssl.sh line 1195:
fileout "app_banner" "WARN" "Application Banners found: $app_banners"
^-- SC2031: app_banners was modified in a subshell. That change might be lost.
```
Found by ShellCheck.
This commit fixes the following two instances of referenced but not assigned
variables:
```
In testssl.sh line 1159:
rp_banners="$rp_bannersline"
^-- SC2154: rp_bannersline is referenced but not assigned.
In testssl.sh line 1193:
app_banners="$app_bannersline"
^-- SC2154: app_bannersline is referenced but not assigned.
```
Found by ShellCheck.
The argument to -nextprotoneg is provided in sometimes empty an unquoted
variables. Because of the missing quotes, the next word on the line "-status"
gets parsed as "-nextprotoneg"'s argument instead of enabling the OCSP status
check.
This fixes#467.
