Files
sendico/api/gateway/mntx/internal/service/monetix/signature.go
2025-12-26 12:26:28 +01:00

113 lines
2.3 KiB
Go

package monetix
import (
"bytes"
"crypto/hmac"
"crypto/sha512"
"encoding/base64"
"encoding/json"
"fmt"
"sort"
"strconv"
"strings"
)
func signPayload(payload any, secret string) (string, error) {
canonical, err := signaturePayloadString(payload)
if err != nil {
return "", err
}
mac := hmac.New(sha512.New, []byte(secret))
if _, err := mac.Write([]byte(canonical)); err != nil {
return "", err
}
return base64.StdEncoding.EncodeToString(mac.Sum(nil)), nil
}
// SignPayload exposes signature calculation for callback verification.
func SignPayload(payload any, secret string) (string, error) {
return signPayload(payload, secret)
}
func signaturePayloadString(payload any) (string, error) {
data, err := json.Marshal(payload)
if err != nil {
return "", err
}
var root any
decoder := json.NewDecoder(bytes.NewReader(data))
decoder.UseNumber()
if err := decoder.Decode(&root); err != nil {
return "", err
}
lines := make([]string, 0)
collectSignatureLines(nil, root, &lines)
sort.Strings(lines)
return strings.Join(lines, ";"), nil
}
func collectSignatureLines(path []string, value any, lines *[]string) {
switch v := value.(type) {
case map[string]any:
for key, child := range v {
if strings.EqualFold(key, "signature") {
continue
}
collectSignatureLines(append(path, key), child, lines)
}
case []any:
if len(v) == 0 {
return
}
for idx, child := range v {
collectSignatureLines(append(path, strconv.Itoa(idx)), child, lines)
}
default:
line := formatSignatureLine(path, v)
if line != "" {
*lines = append(*lines, line)
}
}
}
func formatSignatureLine(path []string, value any) string {
if len(path) == 0 {
return ""
}
val := signatureValueString(value)
segments := append(append([]string{}, path...), val)
return strings.Join(segments, ":")
}
func signatureValueString(value any) string {
switch v := value.(type) {
case nil:
return "null"
case string:
return v
case json.Number:
return v.String()
case bool:
if v {
return "1"
}
return "0"
case float64:
return strconv.FormatFloat(v, 'f', -1, 64)
case float32:
return strconv.FormatFloat(float64(v), 'f', -1, 32)
case int:
return strconv.Itoa(v)
case int8, int16, int32, int64:
return fmt.Sprint(v)
case uint, uint8, uint16, uint32, uint64:
return fmt.Sprint(v)
default:
return fmt.Sprint(v)
}
}