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<p>I would propose one line per protocol for disabled methods. This would allow for easier log parsing</p>
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<p id="reply-intro">On 2022-09-13 06:28, Petr Špaček wrote:</p>
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<div class="pre" style="margin: 0; padding: 0; font-family: monospace"><span style="white-space: nowrap;">On 02. 09. 22 15:49, Anand Buddhdev wrote:</span>
<blockquote type="cite" style="padding: 0 0.4em; border-left: #1010ff 2px solid; margin: 0"><span style="white-space: nowrap;">On 02/09/2022 13:53, Mark Andrews wrote:</span><br /><br /><span style="white-space: nowrap;">Hi Mark,</span><br /><br />
<blockquote type="cite" style="padding: 0 0.4em; border-left: #1010ff 2px solid; margin: 0"><span style="white-space: nowrap;">We don’t log rsamd5 is disabled now ec or ed curves when they are</span><br /><span style="white-space: nowrap;">not supported by the crypto provider. Why should rsasha1 based algs be </span></blockquote>
<span style="white-space: nowrap;">special?</span><br /><br />The problem I see with 9.18.6 is that at startup, it is checking to see if it can validate RSASHA1 signatures, and if it can't, it is disabling the algorithm *silently*. I understand the reasoning, but I disagree with it being disabled silently. If BIND is disabling something as important as this at runtime, at the very least, a log entry about it would go a long way towards helping system administrators. Here's my reasoning:<br /><br />There is a difference between RSAMD5 and RSASHA1. RFC 8624 clearly forbids RSAMD5 for all uses, with "MUST NOT". It's fine for BIND to skip validation for any zone signed with this algorithm.<br /><br />RSASHA1 is quite different. The RFC recommends not signing with it, but validation is still a must. Similarly, it forbids publishing SHA1 digests in DS records, but requires validation using them.<br /><br />Now, on RedHat Linux 9 and its clones, SHA1 is disabled by *policy*. The named.conf from the BIND package in this distro (version 9.16.23) includes the file:<br /><br /><span style="white-space: nowrap;">/etc/crypto-policies/back-ends/bind.config</span><br /><br /><span style="white-space: nowrap;">and this file contains:</span><br /><br /><span style="white-space: nowrap;">disable-algorithms "." {</span><br /><span style="white-space: nowrap;">RSAMD5;</span><br /><span style="white-space: nowrap;">RSASHA1;</span><br /><span style="white-space: nowrap;">NSEC3RSASHA1;</span><br /><span style="white-space: nowrap;">DSA;</span><br /><span style="white-space: nowrap;">};</span><br /><span style="white-space: nowrap;">disable-ds-digests "." {</span><br /><span style="white-space: nowrap;">SHA-1;</span><br /><span style="white-space: nowrap;">GOST;</span><br /><span style="white-space: nowrap;">};</span><br /><br /><span style="white-space: nowrap;">This is explicit declaration that SHA1 has been disabled.</span><br /><br />But if one builds BIND >= 9.18.6 from pristine sources, the configuration file is not going to include this snippet, and BIND is going to silently disable SHA1. I strongly feel that BIND should log this.</blockquote>
<br /><span style="white-space: nowrap;">Can you propose log line?</span><br /><br />Should it be one line per algorithm? Or one line with all disabled? Or one one with all enabled? What log level? Log category? It it okay it will be almost always logging GOST? ...<br /><br />So many questions to get log line covering < 2 % of all signed domains, which will be obsolete over time anyway (hopefully).<br /><br /><span class="sig">-- <br /><span style="white-space: nowrap;">Petr Špaček</span></span></div>
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