rustup TLS warning with newer curl versions (v8.10.0+)

[SergioSierraJr]

Verification

• I searched for recent similar issues at https://github.com/rust-lang/rustup/issues?q=is%3Aissue+is%3Aopen%2Cclosed and found no duplicates.
• I am on the latest version of Rustup according to https://github.com/rust-lang/rustup/tags and am still able to reproduce my issue.

Problem

Basically from what I was told by a user on the discord server, rustups check depends on the help text which has apparently changed so it doesnt see the TLS flag as a possibility. This is an issue with curl because of how it changed.

Steps

1. run curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
2. thats it you just get the following error messages when you run the script

Warning: Not enforcing strong cipher suites for TLS, this is potentially less secure
Warning: Not enforcing TLS v1.2, this is potentially less secure

Possible Solution(s)

Though not a solution, running this before running the script appears to fix the issue

export RUSTUP_TLS_CIPHERSUITES="TLS_AES_128_GCM_SHA256:TLS_CHACHA20_POLY1305_SHA256:TLS_AES_256_GCM_SHA384:ECDHE-ECD
SA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-A
ES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384"

Notes

Apparently, the commit that caused this issue was
curl/curl@9a0cf56#diff-c7bff4c78be0ebe9d665d8a58b8794215b1b679d6e6719616e1738f1d6ca6570L53

Rustup version

Affects curl versions 8.10.0 and above

Installed toolchains

Nonapplicable, first time installing.

OS version

Alpine 8.20

[rami3l]

@SergioSierraJr Thanks for filing this issue! Yes, we're using --help output since it's the easiest way so far to check whether a flag is supported:

rustup/rustup-init.sh

Lines 641 to 645 in a497b15

	_err=$(curl $_retry --proto '=https' --tlsv1.2 --ciphers "$_ciphersuites" --silent --show-error --fail --location "$1" --output "$2" 2>&1)
	_status=$?
	else
	warn "Not enforcing strong cipher suites for TLS, this is potentially less secure"
	if ! check_help_for "$3" curl --proto --tlsv1.2; then

If I understand you correctly, did you mean this filter is too narrow?

rustup/rustup-init.sh

Line 709 in a497b15

if "$_cmd" --help | grep -q 'For all options use the manual or "--help all".'; then

... if so then indeed, I think '"--help all"' would suffice.

[rami3l]

@rustbot claim