spf2ip

package module

v0.0.0-...-7dad53a Latest Latest Go to latest Published: Jun 17, 2025 License: MIT Imports: 12 Imported by: 0

Details

Valid go.mod file
Redistributable license
Tagged version
Stable version
Learn more about best practices

Repository

github.com/HENNGE/spf2ip-go

Links

Open Source Insights

README ¶

SPF2IP-Go

A Go implementation designed to resolve a domain's SPF (Sender Policy Framework) records into a list of IP addresses and CIDR blocks. This project is a remake of and inspired by the original Python-based SPF2IP by Nathan Dines.

This tool recursively processes SPF records, handling include and redirect mechanisms, and extracts all authorized IP networks.

Features

Resolves SPF records for a given domain.
Supports both IPv4 and IPv6 resolution (ip4, ip6, a, mx mechanisms).
Handles include and redirect mechanisms recursively.
Implements strict redirect logic (a redirect overrides preceding mechanisms in the same record).
Detects and prevents resolution loops and excessive lookups (via include depth limit).
Outputs all IPs and networks in canonical CIDR notation (e.g., 1.2.3.4/32, 10.0.0.0/24), sorted and unique.

Acknowledgements

This project is a Go remake of the original SPF2IP (Python) by Nathan Dines. Full credit and thanks to Nathan Dines for the original concept and implementation.

Installation

Building from Source

To build the spf2ip-go executable from source, follow these steps:

Clone the repository:

git clone https://github.com/HENNGE/spf2ip-go.git
cd spf2ip-go

Build the executable:
```
go build github.com/HENNGE/spf2ip-go/cmd/spf2ip-go
```
This will create an executable named spf2ip-go in the current directory.

Using Go Modules

If you prefer to use Go modules, you can run the following command to install the package:

go install github.com/HENNGE/spf2ip-go/cmd/spf2ip-go@latest

CLI Usage

spf2ip-go --domain <domain_name> [--ip-version <4|6>] [--debug]

Flags

--domain <string>: (Required) The domain for which the SPF records should be resolved.
--ip-version <int>: (Optional) The IP version to extract. Accepts 4 for IPv4 or 6 for IPv6. Defaults to 4.
--debug: (Optional) Enable debug logging output to stderr. Defaults to false.

Examples

Get IPv4 addresses for example.com:
```
spf2ip-go --domain example.com
```

Get IPv6 addresses for example.com:

spf2ip-go --domain example.com --ip-version 6

Get IPv4 addresses for example.com with debug output:
```
spf2ip-go --domain example.com --debug
```

Documentation ¶

Overview ¶

Code generated by MockGen. DO NOT EDIT. Source: spf2ip.go

Generated by this command:

mockgen -package spf2ip -source spf2ip.go -destination netresolver_mock.go

Package spf2ip is a generated GoMock package.

Index ¶

Variables
type MockNetResolver
- func NewMockNetResolver(ctrl *gomock.Controller) *MockNetResolver
type MockNetResolverMockRecorder
type NetResolver
type SPF2IPResolver
- func NewSPF2IPResolver(netResolver NetResolver, debugLogging bool) *SPF2IPResolver
- func (r *SPF2IPResolver) Resolve(ctx context.Context, domain string, ipVersion int) ([]string, error)

Constants ¶

This section is empty.

Variables ¶

View Source

var (
	ErrInvalidIPVersion = errors.New("spf2ip: invalid IP version specified, must be 4 or 6")
	ErrLoopDetected     = errors.New("spf2ip: loop detected in SPF resolution")
	ErrExceededMaxDepth = errors.New("spf2ip: maximum SPF include depth exceeded")
)

Functions ¶

This section is empty.

Types ¶

type MockNetResolver ¶

type MockNetResolver struct {
	// contains filtered or unexported fields
}

MockNetResolver is a mock of NetResolver interface.

func NewMockNetResolver ¶

func NewMockNetResolver(ctrl *gomock.Controller) *MockNetResolver

NewMockNetResolver creates a new mock instance.

func (*MockNetResolver) EXPECT ¶

func (m *MockNetResolver) EXPECT() *MockNetResolverMockRecorder

EXPECT returns an object that allows the caller to indicate expected use.

func (*MockNetResolver) LookupIP ¶

func (m *MockNetResolver) LookupIP(ctx context.Context, network, host string) ([]net.IP, error)

LookupIP mocks base method.

func (*MockNetResolver) LookupMX ¶

func (m *MockNetResolver) LookupMX(ctx context.Context, domain string) ([]*net.MX, error)

LookupMX mocks base method.

func (*MockNetResolver) LookupTXT ¶

func (m *MockNetResolver) LookupTXT(ctx context.Context, domain string) ([]string, error)

LookupTXT mocks base method.

type MockNetResolverMockRecorder ¶

type MockNetResolverMockRecorder struct {
	// contains filtered or unexported fields
}

MockNetResolverMockRecorder is the mock recorder for MockNetResolver.

func (*MockNetResolverMockRecorder) LookupIP ¶

func (mr *MockNetResolverMockRecorder) LookupIP(ctx, network, host any) *gomock.Call

LookupIP indicates an expected call of LookupIP.

func (*MockNetResolverMockRecorder) LookupMX ¶

func (mr *MockNetResolverMockRecorder) LookupMX(ctx, domain any) *gomock.Call

LookupMX indicates an expected call of LookupMX.

func (*MockNetResolverMockRecorder) LookupTXT ¶

func (mr *MockNetResolverMockRecorder) LookupTXT(ctx, domain any) *gomock.Call

LookupTXT indicates an expected call of LookupTXT.

type NetResolver ¶

type NetResolver interface {
	LookupIP(ctx context.Context, network, host string) ([]net.IP, error)
	LookupMX(ctx context.Context, domain string) ([]*net.MX, error)
	LookupTXT(ctx context.Context, domain string) ([]string, error)
}

type SPF2IPResolver ¶

type SPF2IPResolver struct {
	// contains filtered or unexported fields
}

func NewSPF2IPResolver ¶

func NewSPF2IPResolver(netResolver NetResolver, debugLogging bool) *SPF2IPResolver

func (*SPF2IPResolver) Resolve ¶

func (r *SPF2IPResolver) Resolve(ctx context.Context, domain string, ipVersion int) ([]string, error)

Source Files ¶

View all Source files

Directories ¶

Path	Synopsis
cmd
spf2ip-go command

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