### Handle IPNS Errors in Go

Source: https://context7.com/ipfs/go-ipns/llms.txt

This example demonstrates how to create IPNS records with intentional errors and use the go-ipns validation functions to identify specific failure conditions such as expired records or invalid signatures. It relies on the go-libp2p crypto package for key generation and the ipns package for record creation and validation. The output lists detected errors and prints common IPNS error constants.

```go
package main

import (
	"errors"
	"fmt"
	"time"

	"github.com/ipfs/go-ipns"
	"github.com/libp2p/go-libp2p/core/crypto"
)

func main() {
	privateKey, public _ := crypto.GenerateKeyPair(crypto.RSA, 2048)
	ipfsPath := []byte("/ipfs/QmErrorTest")

	// Test expired record error
	pastTime := time.Now().Add(-1 * time.Hour)
	expiredRecord, _ := ipns.Create(privateKey, ipfsPath, 0, pastTime, 0)
	err := ipns.Validate(publicKey, expiredRecord)
	if errors.Is(err, ipns.ErrExpiredRecord) {
		fmt.Println("Detected ErrExpiredRecord: record has expired")
	}

	// Test signature error with wrong key
	_, wrongKey, _ := crypto.GenerateKeyPair(crypto.RSA, 2048)
	validRecord, _ := ipns.Create(privateKey, ipfsPath, 0, time.Now().Add(1*time.Hour), 0)
	err = ipns.Validate(wrongKey, validRecord)
	if errors.Is(err, ipns.ErrSignature) {
		fmt.Println("Detected ErrSignature: signature verification failed")
	}

	// Other common errors
	fmt.Println("\nCommon IPNS errors:")
	fmt.Printf("  ErrInvalidPath: %v\n", ipns.ErrInvalidPath)
	fmt.Printf("  ErrKeyFormat: %v\n", ipns.ErrKeyFormat)
	fmt.Printf("  ErrPublicKeyNotFound: %v\n", ipns.ErrPublicKeyNotFound)
	fmt.Printf("  ErrPublicKeyMismatch: %v\n", ipns.ErrPublicKeyMismatch)
	fmt.Printf("  ErrBadRecord: %v\n", ipns.ErrBadRecord)
	fmt.Printf("  ErrRecordSize: %v (max: %d bytes)\n", ipns.ErrRecordSize, ipns.MaxRecordSize)
	fmt.Printf("  ErrUnrecognizedValidity: %v\n", ipns.ErrUnrecognizedValidity)
}
```

--------------------------------

### Create IPNS record in Go

Source: https://context7.com/ipfs/go-ipns/llms.txt

Creates a new cryptographically signed IPNS record that points to an IPFS path with a specified expiration time and sequence number. Requires RSA key pair generation and uses the go-ipns and go-libp2p libraries. The example demonstrates creating a record that expires in one hour.

```go
package main

import (
	"fmt"
	"time"

	"github.com/ipfs/go-ipns"
	"github.com/libp2p/go-libp2p/core/crypto"
)

func main() {
	// Generate RSA key pair for signing
	privateKey, publicKey, err := crypto.GenerateKeyPair(crypto.RSA, 2048)
	if err != nil {
		panic(fmt.Errorf("failed to generate key pair: %w", err))
	}

	// IPFS content path to point to
	ipfsPath := []byte("/ipfs/Qme1knMqwt1hKZbc1BmQFmnm9f36nyQGwXxPGVpVJ9rMK5")

	// Create record with sequence 0, expires in 1 hour, no TTL
	eol := time.Now().Add(1 * time.Hour)
	record, err := ipns.Create(privateKey, ipfsPath, 0, eol, 0)
	if err != nil {
		panic(fmt.Errorf("failed to create IPNS record: %w", err))
	}

	fmt.Printf("Created IPNS record:\n")
	fmt.Printf("  Value: %s\n", string(record.Value))
	fmt.Printf("  Sequence: %d\n", record.GetSequence())
	fmt.Printf("  Validity: %s\n", string(record.Validity))
	fmt.Printf("  Has SignatureV2: %v\n", record.SignatureV2 != nil)
}
```

--------------------------------

### Generate IPNS Key Pairs using Go

Source: https://context7.com/ipfs/go-ipns/llms.txt

This snippet shows how to generate RSA and Ed25519 key pairs with the go-ipns examples package, extract the corresponding peer IDs, and display key metadata. It depends on the go-libp2p core peer package and requires no external input beyond the key size for RSA. The code outputs the generated keys' peer IDs and types, useful for publishing IPNS records.

```go
package main

import (
	"fmt"

	"github.com/ipfs/go-ipns/examples"
	"github.com/libp2p/go-libp2p/core/peer"
)

func main() {
	// Generate RSA key pair (2048 bits)
	rsaPrivKey, err := examples.GenerateRSAKeyPair(2048)
	if err != nil {
		panic(fmt.Errorf("failed to generate RSA key: %w", err))
	}
	rsaPubKey := rsaPrivKey.GetPublic()
	rsaPeerID, _ := peer.IDFromPublicKey(rsaPubKey)
	fmt.Printf("Generated RSA key pair\n")
	fmt.Printf("  Peer ID: %s\n", rsaPeerID.String())
	fmt.Printf("  Key type: %s\n", rsaPrivKey.Type())

	// Generate Ed25519 key pair
	ed25519PrivKey, err := examples.GenerateEDKeyPair()
	if err != nil {
		panic(fmt.Errorf("failed to generate Ed25519 key: %w", err))
	}
	ed25519PubKey := ed25519PrivKey.GetPublic()
	ed25519PeerID, _ := peer.IDFromPublicKey(ed25519PubKey)
	fmt.Printf("\nGenerated Ed25519 key pair\n")
	fmt.Printf("  Peer ID: %s\n", ed25519PeerID.String())
	fmt.Printf("  Key type: %s\n", ed25519PrivKey.Type())

	// Note: Ed25519 public keys can be extracted from peer ID
	extractedKey, err := ed25519PeerID.ExtractPublicKey()
	if err == nil {
		fmt.Println("  Ed25519 public key can be extracted from peer ID")
	} else {
		fmt.Println("  Public key cannot be extracted from peer ID")
	}
}
```

--------------------------------

### Validate IPNS record in Go

Source: https://context7.com/ipfs/go-ipns/llms.txt

Validates an IPNS record by verifying its cryptographic signature, checking expiration time, and ensuring data integrity. Uses the go-ipns and go-libp2p libraries. The example shows validation of both valid and expired records, demonstrating error handling for expired records.

```go
package main

import (
	"fmt"
	"time"

	"github.com/ipfs/go-ipns"
	pb "github.com/ipfs/go-ipns/pb"
	"github.com/libp2p/go-libp2p/core/crypto"
)

func main() {
	// Create a test record
	privateKey, publicKey, _ := crypto.GenerateKeyPair(crypto.RSA, 2048)
	ipfsPath := []byte("/ipfs/QmTest123")
	eol := time.Now().Add(24 * time.Hour)
	record, _ := ipns.Create(privateKey, ipfsPath, 0, eol, 0)

	// Validate the record
	err := ipns.Validate(publicKey, record)
	if err != nil {
		fmt.Printf("Validation failed: %v\n", err)
		return
	}
	fmt.Println("Record validation successful")

	// Test with expired record
	expiredEol := time.Now().Add(-1 * time.Hour)
	expiredRecord, _ := ipns.Create(privateKey, ipfsPath, 1, expiredEol, 0)
	err = ipns.Validate(publicKey, expiredRecord)
	if err == ipns.ErrExpiredRecord {
		fmt.Println("Correctly detected expired record")
	}
}
```

--------------------------------

### Embed and extract public key in Go

Source: https://context7.com/ipfs/go-ipns/llms.txt

Embeds a public key in an IPNS record for validation by nodes that cannot derive the key from the peer ID. Requires RSA key pair generation and uses the go-ipns and go-libp2p libraries. The example demonstrates embedding a public key in a record and then extracting and verifying it.

```go
package main

import (
	"fmt"
	"time"

	"github.com/ipfs/go-ipns"
	"github.com/libp2p/go-libp2p/core/crypto"
	"github.com/libp2p/go-libp2p/core/peer"
)

func main() {
	// Generate RSA key pair (RSA keys cannot be extracted from peer ID)
	privateKey, publicKey, err := crypto.GenerateKeyPair(crypto.RSA, 2048)
	if err != nil {
		panic(err)
	}

	peerID, _ := peer.IDFromPublicKey(publicKey)

	// Create IPNS record
	ipfsPath := []byte("/ipfs/QmExample")
	eol := time.Now().Add(48 * time.Hour)
	record, _ := ipns.Create(privateKey, ipfsPath, 0, eol, 0)

	// Embed public key in record
	err = ipns.EmbedPublicKey(publicKey, record)
	if err != nil {
		panic(fmt.Errorf("failed to embed public key: %w", err))
	}
	fmt.Printf("Embedded public key in record (size: %d bytes)\n", len(record.PubKey))

	// Extract public key from record
	extractedKey, err := ipns.ExtractPublicKey(peerID, record)
	if err != nil {
		panic(fmt.Errorf("failed to extract public key: %w", err))
	}

	// Verify extracted key matches original
	extractedPeerID, _ := peer.IDFromPublicKey(extractedKey)
	if extractedPeerID == peerID {
		fmt.Println("Successfully extracted and verified public key")
	}
}
```

--------------------------------

### Compare IPNS Records in Go

Source: https://context7.com/ipfs/go-ipns/llms.txt

This code demonstrates comparing two IPNS records to determine which is newer based on sequence number and validity timestamp. It uses the go-ipns library to create records and perform comparisons, outputting results for different scenarios. The function handles sequence-based ordering and expiration time differences, assuming valid crypto keys and paths.

```go
package main

import (
	"fmt"
	"time"

	"github.com/ipfs/go-ipns"
	"github.com/libp2p/go-libp2p/core/crypto"
)

func main() {
	privateKey, _, _ := crypto.GenerateKeyPair(crypto.RSA, 2048)
	ipfsPath := []byte("/ipfs/QmTest")

	// Create two records with different sequences
	record1, _ := ipns.Create(privateKey, ipfsPath, 0, time.Now().Add(1*time.Hour), 0)
	record2, _ := ipns.Create(privateKey, ipfsPath, 1, time.Now().Add(1*time.Hour), 0)

	result, err := ipns.Compare(record1, record2)
	if err != nil {
		panic(fmt.Errorf("comparison failed: %w", err))
	}

	switch result {
	case -1:
		fmt.Println("Record 1 is older than Record 2")
	case 0:
		fmt.Println("Records cannot be ordered")
	case 1:
		fmt.Println("Record 1 is newer than Record 2")
	}

	// Compare with different validity times but same sequence
	futureEol := time.Now().Add(48 * time.Hour)
	record3, _ := ipns.Create(privateKey, ipfsPath, 1, futureEol, 0)

	result, _ = ipns.Compare(record2, record3)
	if result == -1 {
		fmt.Println("Record with later expiration is considered newer")
	}
}
```

--------------------------------

### Validate IPNS Records with libp2p in Go

Source: https://context7.com/ipfs/go-ipns/llms.txt

This snippet implements a libp2p record validator for IPNS records, validating them using a keybook for distributed systems. It creates records, embeds public keys, serializes them, and performs validation and selection of the best record. Dependencies include go-ipns and libp2p libraries.

```go
package main

import (
	"fmt"
	"time"

	"github.com/gogo/protobuf/proto"
	"github.com/ipfs/go-ipns"
	pb "github.com/ipfs/go-ipns/pb"
	"github.com/libp2p/go-libp2p/core/crypto"
	"github.com/libp2p/go-libp2p/core/peer"
	"github.com/libp2p/go-libp2p/core/peerstore"
)

func main() {
	// Generate key pair and peer ID
	privateKey, publicKey, _ := crypto.GenerateKeyPair(crypto.RSA, 2048)
	peerID, _ := peer.IDFromPublicKey(publicKey)

	// Create and embed public key in record
	ipfsPath := []byte("/ipfs/QmValidatorExample")
	eol := time.Now().Add(24 * time.Hour)
	record, _ := ipns.Create(privateKey, ipfsPath, 0, eol, 0)
	ipns.EmbedPublicKey(publicKey, record)

	// Serialize record
	recordBytes, _ := proto.Marshal(record)

	// Create validator with keybook
	keybook := peerstore.NewKeyBook()
	keybook.AddPubKey(peerID, publicKey)
	validator := ipns.Validator{KeyBook: keybook}

	// Validate using the key format /ipns/{peerID}
	key := ipns.RecordKey(peerID)
	err := validator.Validate(key, recordBytes)
	if err != nil {
		fmt.Printf("Validation failed: %v\n", err)
		return
	}
	fmt.Printf("Record validated successfully for key: %s\n", key)

	// Test record selection (choosing best record from multiple)
	record2, _ := ipns.Create(privateKey, ipfsPath, 1, eol, 0)
	ipns.EmbedPublicKey(publicKey, record2)
	record2Bytes, _ := proto.Marshal(record2)

	bestIndex, err := validator.Select(key, [][]byte{recordBytes, record2Bytes})
	if err != nil {
		panic(err)
	}
	fmt.Printf("Best record is at index: %d (should be 1 due to higher sequence)\n", bestIndex)
}
```

--------------------------------

### Create IPNS Record in Go

Source: https://github.com/ipfs/go-ipns/blob/master/README.md

Generates an IPNS record pointing to a given IPFS content identifier, signed with a provided private key and set to expire at a specified time. It requires the `go-ipns` and `go-libp2p-crypto` packages. The output is an IPNS record suitable for publishing.

```go
import (
	time "time"

	ipns "github.com/ipfs/go-ipns"
	crypto "github.com/libp2p/go-libp2p-crypto"
)

// Generate a private key to sign the IPNS record with. Most of the time, 
// however, you'll want to retrieve an already-existing key from IPFS using the
// go-ipfs/core/coreapi CoreAPI.KeyAPI() interface.
privateKey, publicKey, err := crypto.GenerateKeyPair(crypto.RSA, 2048)
if err != nil {
  panic(err)
}

// Create an IPNS record that expires in one hour and points to the IPFS address
// /ipfs/Qme1knMqwt1hKZbc1BmQFmnm9f36nyQGwXxPGVpVJ9rMK5
ipnsRecord, err := ipns.Create(privateKey, []byte("/ipfs/Qme1knMqwt1hKZbc1BmQFmnm9f36nyQGwXxPGVpVJ9rMK5"), 0, time.Now().Add(1*time.Hour))
if err != nil {
	panic(err)
}

```

--------------------------------

### Retrieve EOL Timestamp from IPNS Record in Go

Source: https://context7.com/ipfs/go-ipns/llms.txt

This code retrieves the end-of-life (EOL) timestamp from an IPNS record for making TTL and caching decisions. It creates a record with a set expiration and extracts the timestamp, then checks if it's still valid. Inputs are the record and outputs the timestamp, with limitations on time handling.

```go
package main

import (
	"fmt"
	"time"

	"github.com/ipfs/go-ipns"
	"github.com/libp2p/go-libp2p/core/crypto"
)

func main() {
	privateKey, _, _ := crypto.GenerateKeyPair(crypto.RSA, 2048)
	ipfsPath := []byte("/ipfs/QmEOLTest")

	// Create record expiring in 6 hours
	expirationTime := time.Now().Add(6 * time.Hour)
	record, _ := ipns.Create(privateKey, ipfsPath, 0, expirationTime, 0)

	// Retrieve EOL from record
	eol, err := ipns.GetEOL(record)
	if err != nil {
		panic(fmt.Errorf("failed to get EOL: %w", err))
	}

	fmt.Printf("Record expires at: %s\n", eol.Format(time.RFC3339))
	fmt.Printf("Time until expiration: %s\n", time.Until(eol).Round(time.Minute))

	// Check if record is still valid
	if time.Now().Before(eol) {
		fmt.Println("Record is still valid")
	} else {
		fmt.Println("Record has expired")
	}
}
```

=== COMPLETE CONTENT === This response contains all available snippets from this library. No additional content exists. Do not make further requests.