Files
probo/pkg/agent/tools/security/spf.go
Émile Ré f5703d390b Enforce Go style rules across codebase
Apply five style rules: convert iota string enums to typed
string constants, replace errors.As with errors.AsType,
merge three-group imports into two groups, fix multiline
parameter/argument formatting, and replace fmt.Sprintf URL
construction with net/url.

Signed-off-by: Émile Ré <emile@probo.com>
2026-05-20 11:46:39 +04:00

130 lines
3.1 KiB
Go

// Copyright (c) 2026 Probo Inc <hello@getprobo.com>.
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
// AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
// OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
// PERFORMANCE OF THIS SOFTWARE.
package security
import (
"context"
"fmt"
"strings"
"codeberg.org/miekg/dns"
"go.probo.inc/probo/pkg/agent"
)
type (
spfParams struct {
Domain string `json:"domain" jsonschema:"The domain to check SPF record for (e.g. example.com)"`
}
spfResult struct {
Found bool `json:"found"`
RawRecord string `json:"raw_record,omitempty"`
Policy string `json:"policy,omitempty"`
Mechanisms string `json:"mechanisms,omitempty"`
ErrorDetail string `json:"error_detail,omitempty"`
}
)
func parseSPFPolicy(record string) string {
for part := range strings.FieldsSeq(strings.ToLower(record)) {
switch part {
case "-all":
return "fail"
case "~all":
return "softfail"
case "?all":
return "neutral"
case "+all":
return "pass"
}
}
return ""
}
func CheckSPFTool() agent.Tool {
return agent.FunctionTool(
"check_spf",
"Check the SPF (Sender Policy Framework) DNS record for a domain, returning the raw record and its policy qualifier.",
func(ctx context.Context, p spfParams) (agent.ToolResult, error) {
fqdn := p.Domain
if !strings.HasSuffix(fqdn, ".") {
fqdn = fqdn + "."
}
client := dns.NewClient()
answers, err := queryDNS(
ctx,
client,
&dns.TXT{
Hdr: dns.Header{
Name: fqdn,
Class: dns.ClassINET,
},
},
)
if err != nil {
return agent.ResultJSON(
spfResult{
Found: false,
ErrorDetail: fmt.Sprintf("cannot lookup SPF record: %s", err),
},
), nil
}
var spfRecords []string
for _, answer := range answers {
txt, ok := answer.(*dns.TXT)
if !ok {
continue
}
record := strings.Join(txt.Txt, "")
if !strings.HasPrefix(strings.ToLower(record), "v=spf1") {
continue
}
spfRecords = append(spfRecords, record)
}
if len(spfRecords) > 1 {
return agent.ResultJSON(
spfResult{
Found: true,
ErrorDetail: fmt.Sprintf("multiple SPF records found (%d); this is an invalid configuration per RFC 7208", len(spfRecords)),
},
), nil
}
if len(spfRecords) == 1 {
record := spfRecords[0]
return agent.ResultJSON(
spfResult{
Found: true,
RawRecord: record,
Policy: parseSPFPolicy(record),
Mechanisms: record,
},
), nil
}
return agent.ResultJSON(spfResult{Found: false}), nil
},
)
}