Files
opentimestamps/verifyer/esplora.go
2025-04-11 13:31:02 +02:00

86 lines
1.8 KiB
Go

package verifyer
import (
"bytes"
"encoding/hex"
"fmt"
"io"
"net/http"
"strconv"
"strings"
"time"
"slices"
"github.com/btcsuite/btcd/chaincfg/chainhash"
"github.com/btcsuite/btcd/wire"
)
// esplora is a client for the Esplora API, which provides access to Bitcoin
// blockchain data.
type esplora struct {
httpClient *http.Client
baseURL string
}
func NewEsploraClient(url string, timeout time.Duration) Bitcoin {
url = strings.TrimSuffix(url, "/")
h := &http.Client{
Timeout: timeout,
}
return esplora{h, url}
}
func (e esplora) GetBlockHash(height int64) (*chainhash.Hash, error) {
resp, err := e.httpClient.Get(e.baseURL + "/block-height/" + strconv.FormatInt(height, 10))
if err != nil {
return nil, fmt.Errorf("failed to get block hash: %w", err)
}
defer resp.Body.Close()
hexb, err := io.ReadAll(resp.Body)
if err != nil {
return nil, fmt.Errorf("failed to read block hash: %w", err)
}
hash, err := hex.DecodeString(string(hexb))
if err != nil {
return nil, fmt.Errorf("failed to decode block hash: %w", err)
}
if len(hash) != chainhash.HashSize {
return nil, fmt.Errorf("got block hash (%x) of invalid size (expected %d)", hash, chainhash.HashSize)
}
slices.Reverse(hash)
var chash chainhash.Hash
copy(chash[:], hash)
return &chash, nil
}
func (e esplora) GetBlockHeader(hash *chainhash.Hash) (*wire.BlockHeader, error) {
resp, err := e.httpClient.Get(fmt.Sprintf("%s/block/%s/header", e.baseURL, hash.String()))
if err != nil {
return nil, err
}
defer resp.Body.Close()
hexb, err := io.ReadAll(resp.Body)
if err != nil {
return nil, err
}
headerHash, err := hex.DecodeString(string(hexb))
if err != nil {
return nil, err
}
header := &wire.BlockHeader{}
if err := header.BtcDecode(bytes.NewBuffer(headerHash), 0, 0); err != nil {
return nil, err
}
return header, nil
}