Re: [PATCH proxmox v4 2/8] http: tls: use legacy behavior when PROXMOX_OLD_TLS_CHECK is set to "1"

["Shannon Sterz" <s.sterz@proxmox.com>]

On Wed Jul 1, 2026 at 12:30 PM CEST, Dominik Csapak wrote:
> If that environment variable is set to "1", give the openssl result
> priority, and potentially ignore a given fingerprint that is not
> matching. If that's the case, print a warning.

nit: the "print a warning" bit was moved to the next commit, so im
guessing the commit message should be cleaned up here :)

> Co-developed-by: Shannon Sterz <s.sterz@proxmox.com>
> Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
> ---
>  proxmox-http/src/tls.rs | 15 +++++++++++++--
>  1 file changed, 13 insertions(+), 2 deletions(-)
>
> diff --git a/proxmox-http/src/tls.rs b/proxmox-http/src/tls.rs
> index 5c2b1743..abdf51e9 100644
> --- a/proxmox-http/src/tls.rs
> +++ b/proxmox-http/src/tls.rs
> @@ -103,6 +103,8 @@ impl std::str::FromStr for Fingerprint {
>      }
>  }
>
> +pub const PROXMOX_OLD_TLS_CHECK_VAR: &str = "PROXMOX_OLD_TLS_CHECK";
> +
>  ///
>  /// Error type returned by failed [`openssl_verify_callback`].
>  ///
> @@ -159,15 +161,24 @@ impl PartialEq for SslVerifyError {
>
>  /// Intended as an openssl verification callback.
>  ///
> -/// The following things are checked:
> +/// If the 'PROXMOX_OLD_TLS_CHECK' environment variable is not set to "1",
> +/// the following things are checked:
>  ///
>  /// * If no fingerprint is given, return the openssl verification result
> -/// * If a fingerprint is given get the leaf fp and check that against the given
> +/// * If a fingerprint is given, check it against the leaf fp
> +///
> +/// Otherwise, we trust the openssl result if the whole chain was trusted
>  pub fn openssl_verify_callback(
>      openssl_valid: bool,
>      ctx: &mut X509StoreContextRef,
>      expected_fp: Option<Fingerprint>,
>  ) -> Result<(), SslVerifyError> {
> +    let old_check = matches!(std::env::var(PROXMOX_OLD_TLS_CHECK_VAR).as_deref(), Ok("1"));
> +
> +    if old_check && openssl_valid {
> +        return Ok(());
> +    }
> +
>      match expected_fp {
>          Some(expected_fp) => {
>              let fingerprint = get_leaf_fp(ctx)?;