README
¶
Go-SPF
TL;DR
To add this package to your go imports, use
go get github.com/moverval/go-spf
This package provides easy to use features, to validate, if an IP belongs to a network.
It supports all spf1 mechanisms and the redirect modifier.
To check if an ip belongs to a network
// ValidateIP(ip, domain, nameserver, follows)
result, err := spf.ValidateIP(net.ParseIP("35.190.247.10"), "gmail.com", "8.8.8.8:53", 3)
if err != nil {
// handle error
}
switch result {
case spf.PassQualifier:
// IP belongs to network
case spf.NeutralQualifier:
// IP was found but no conclusion can be made
case spf.NoneQualifier:
// No match was found for the ip. This should be treated as Neutral
case spf.SoftFailQualifier:
// IP is probably not from the network
case spf.FailQualifier:
// IP is not from the network
}
Errors
All custom error types can be seen in errors.go. If an error get's thrown, it is most of the time the issuers fault, but errors can also occur if a dns record could not be resolved.
Examples of errors:
- Syntax
The spf record has an invalid syntax.
- OutOfRecursions
The issuer exceeded the include or redirect depth. (Use -1 to make the depth infinite; not recommended)
Lookup SPF
SPF can also only be queried. If you only want the spf record string, use LookupSPF
record, err := spf.LookupSPF("gmail.com", "8.8.8.8:53")
if err != nil {
// handle error
}
// do something with the record
Parse SPF
This library has a custom parser to evaluate spf strings. It handles strings gracefully and tries to interpret them correctly even if they are false.
result, err := spf.ParseSPF("v=spf1 -include:ban.voulter.com include:spf.voulter.com include:spf2.voulter.com a:voulter.com ip4:127.0.0.1 ip6:::1 ~all")
var expected spf.Record = []spf.Mechanism{
{Qualifier: spf.FailQualifier, Mechanism: spf.IncludeMechanism, Value: "ban.voulter.com"},
{Qualifier: spf.PassQualifier, Mechanism: spf.IncludeMechanism, Value: "spf.voulter.com"},
{Qualifier: spf.PassQualifier, Mechanism: spf.IncludeMechanism, Value: "spf2.voulter.com"},
{Qualifier: spf.PassQualifier, Mechanism: spf.AMechanism, Value: "voulter.com"},
{Qualifier: spf.PassQualifier, Mechanism: spf.IPv4Mechanism, Value: "127.0.0.1"},
{Qualifier: spf.PassQualifier, Mechanism: spf.IPv6Mechanism, Value: "::1"},
{Qualifier: spf.SoftFailQualifier, Mechanism: spf.AllMechanism, Value: ""},
}
if err != nil {
// handle error
// an error should not occur in this example
}
if reflect.DeepEqual(result, expected) {
// this is true
}
Advanced: Partial Parse SPF
Because Subcomponents are exposed by design, it is possible the evaluate individual Mechanisms seperately. For more information look at interpreter.go/ExecuteMechanism.
Documentation
¶
Index ¶
- Constants
- Variables
- func IsSPF(spf string) bool
- func LookupARec(domain string, nameserver string) (net.IP, error)
- func LookupSPF(domain string, nameserver string) (string, error)
- func MatchIP(ip net.IP, ip2 string) (bool, error)
- func MatchIPWithARec(ip net.IP, domain string, nameserver string) (bool, error)
- func MatchIPWithCIDR(ip net.IP, cidr string) (bool, error)
- func MatchIPWithMXRec(ip net.IP, domain string, nameserver string) (bool, error)
- func MatchIPWithPtrRec(ip net.IP, domain string, nameserver string) (bool, error)
- type Mechanism
- type MechanismParseContext
- type Qualifier
- type Record
- type Result
Constants ¶
const ( PassQualifier = iota // + FailQualifier // - SoftFailQualifier // ~ NeutralQualifier // ? NoneQualifier // No Mechanism matched the current ip )
A Qualifier can be -, +, ~, ?
const ( AllMechanism = iota + 1 // all IPv4Mechanism // ip4 IPv6Mechanism // ip6 AMechanism // a MXMechanism // mx PTRMechanism // ptr ExistsMechanism // exists IncludeMechanism // include RedirectMechanism // redirect )
Caution! Modifiers are also called mechanisms in this library, but they get distinguished correctly
Variables ¶
var ErrInvalidMechanism error = errors.New("invalidmechanism") // Unknwon mechanism keyword received
var ErrInvalidModifier error = errors.New("invalidmodifier") // Unknown modifier received
var ErrInvalidQualifier error = errors.New("invalidqualifier") // Other character than +, -, ~, ? for a qualifier received
var ErrNotFound error = errors.New("notfound") // DNS entry not found
var ErrOutOfRecursions = errors.New("outofrecursions") // Too many redirect or include mechanisms were called
var ErrSyntax error = errors.New("syntax") // Syntax error in ParseSPF
Functions ¶
func LookupARec ¶
Returns first a record as net.IP
Returns an error if dns name couldn't be resolved
func LookupSPF ¶
Get an SPF Record as string from a domain
Returns an error if no spf record is found or dns name couldn't be resolved
func MatchIPWithARec ¶
Checks if ip is contained in a record
Returns an error if dns name couldn't be resolved
func MatchIPWithMXRec ¶
Checks if ip is found in a record which was referenced by mx record
Returns an error if dns name couldn't be resolved
Types ¶
type Mechanism ¶
An Argument in the SPF Record They are read from left to right (Left is the most powerful one) Qualifiers determine how the ip should be treated if the mechanism matches the address
func EvaluateMechanism ¶
func EvaluateMechanism(context *MechanismParseContext) (Mechanism, error)
func EvaluateModifier ¶
func EvaluateModifier(context *MechanismParseContext) (Mechanism, error)
type MechanismParseContext ¶
type Qualifier ¶
type Qualifier int
Source Files