mox/tlsrpt/alert_go120.go

//go:build !go1.21

// For go1.20 and earlier.

package tlsrpt

import (
	"fmt"
)

// FormatAlert formats a TLS alert in the form "alert-<num>".
func FormatAlert(alert uint8) string {
	return fmt.Sprintf("alert-%d", alert)
}
implement outgoing tls reports we were already accepting, processing and displaying incoming tls reports. now we start tracking TLS connection and security-policy-related errors for outgoing message deliveries as well. we send reports once a day, to the reporting addresses specified in TLSRPT records (rua) of a policy domain. these reports are about MTA-STS policies and/or DANE policies, and about STARTTLS-related failures. sending reports is enabled by default, but can be disabled through setting NoOutgoingTLSReports in mox.conf. only at the end of the implementation process came the realization that the TLSRPT policy domain for DANE (MX) hosts are separate from the TLSRPT policy for the recipient domain, and that MTA-STS and DANE TLS/policy results are typically delivered in separate reports. so MX hosts need their own TLSRPT policies. config for the per-host TLSRPT policy should be added to mox.conf for existing installs, in field HostTLSRPT. it is automatically configured by quickstart for new installs. with a HostTLSRPT config, the "dns records" and "dns check" admin pages now suggest the per-host TLSRPT record. by creating that record, you're requesting TLS reports about your MX host. gathering all the TLS/policy results is somewhat tricky. the tentacles go throughout the code. the positive result is that the TLS/policy-related code had to be cleaned up a bit. for example, the smtpclient TLS modes now reflect reality better, with independent settings about whether PKIX and/or DANE verification has to be done, and/or whether verification errors have to be ignored (e.g. for tls-required: no header). also, cached mtasts policies of mode "none" are now cleaned up once the MTA-STS DNS record goes away. 2023-11-09 19:40:46 +03:00			`//go:build !go1.21`

			`// For go1.20 and earlier.`

			`package tlsrpt`

			`import (`
			`"fmt"`
			`)`

smtpserver: add prometheus metric for failing starttls handshakes for incoming deliveries and add an alerting rule if the failure rate becomes >10% (e.g. expired certificate). the prometheus metrics includes a reason, including potential tls alerts, if remote smtp clients would send those (openssl s_client -starttls does). inspired by issue #237, where incoming connections were aborted by remote. such errors would show up as "eof" in the metrics. 2024-11-29 14:43:21 +03:00			`// FormatAlert formats a TLS alert in the form "alert-<num>".`
			`func FormatAlert(alert uint8) string {`
implement outgoing tls reports we were already accepting, processing and displaying incoming tls reports. now we start tracking TLS connection and security-policy-related errors for outgoing message deliveries as well. we send reports once a day, to the reporting addresses specified in TLSRPT records (rua) of a policy domain. these reports are about MTA-STS policies and/or DANE policies, and about STARTTLS-related failures. sending reports is enabled by default, but can be disabled through setting NoOutgoingTLSReports in mox.conf. only at the end of the implementation process came the realization that the TLSRPT policy domain for DANE (MX) hosts are separate from the TLSRPT policy for the recipient domain, and that MTA-STS and DANE TLS/policy results are typically delivered in separate reports. so MX hosts need their own TLSRPT policies. config for the per-host TLSRPT policy should be added to mox.conf for existing installs, in field HostTLSRPT. it is automatically configured by quickstart for new installs. with a HostTLSRPT config, the "dns records" and "dns check" admin pages now suggest the per-host TLSRPT record. by creating that record, you're requesting TLS reports about your MX host. gathering all the TLS/policy results is somewhat tricky. the tentacles go throughout the code. the positive result is that the TLS/policy-related code had to be cleaned up a bit. for example, the smtpclient TLS modes now reflect reality better, with independent settings about whether PKIX and/or DANE verification has to be done, and/or whether verification errors have to be ignored (e.g. for tls-required: no header). also, cached mtasts policies of mode "none" are now cleaned up once the MTA-STS DNS record goes away. 2023-11-09 19:40:46 +03:00			`return fmt.Sprintf("alert-%d", alert)`
			`}`