• Go Signature Generator
  • sg.go

#Go Signature Generator

#sg.go

package ssofy

import (
    "crypto/hmac"
    "crypto/sha256"
    "encoding/hex"
    "fmt"
    "net/url"
    "sort"
    "strings"
)

type Signature struct {
    Hash string `json:"hash"`
    Salt string `json:"salt"`
}

func GenerateSignature(urlStr string, params interface{}, secret string, salt string) (Signature, error) {
    u, err := url.Parse(urlStr)
    if err != nil {
        return Signature{}, err
    }

    path := u.Path

    toSign := path + getValues(params, "") + salt
    hash, err := generateHMAC(toSign, []byte(secret))
    if err != nil {
        return Signature{}, err
    }

    return Signature{
        Hash: hash,
        Salt: salt,
    }, nil
}

func generateHMAC(message string, key []byte) (string, error) {
    h := hmac.New(sha256.New, key)
    _, err := h.Write([]byte(message))
    if err != nil {
        return "", err
    }
    hash := hex.EncodeToString(h.Sum(nil))
    return hash, nil
}

func getValues(obj interface{}, prefix string) string {
    var values []string

    if m, ok := obj.(map[string]interface{}); ok {
        keys := make([]string, 0, len(m))
        for k := range m {
            keys = append(keys, k)
        }
        sort.Strings(keys)

        for _, k := range keys {
            values = append(values, getValues(m[k], k))
        }
    } else if s, ok := obj.([]interface{}); ok {
        for i, v := range s {
            values = append(values, getValues(v, fmt.Sprintf("%s[%d]", prefix, i)))
        }
    } else if b, ok := obj.(bool); ok {
        if b {
            values = append(values, "1")
        } else {
            values = append(values, "0")
        }
    } else if obj == nil {
        values = append(values, "")
    } else {
        values = append(values, fmt.Sprintf("%v", obj))
    }

    return strings.Join(values, "")
}