Lazada Open Platform verifies the identity of each API request, and the server will also verify whether the call parameters are valid. Therefore, each HTTP request must contain the signature information. The requests with invalid signature will be rejected.
Lazada Open Platform verifies the identity of the requests by the App Key and Secret that are assigned to your application. The App Secret is used to generate the signature string in the HTTP request URL and server-side signature string. It must be kept strictly confidential.
If you compose HTTP request manually (instead of using the official SDK), you need to understand the following signature algorithm.
The process of generating the signature is as follows:
Before sort: foo=1, bar=2, foo_bar=3, foobar=4 After sort: bar=2, foo=1, foo_bar=3, foobar=4
bar2foo1foo_bar3foobar4
/test/apibar2foo1foo_bar3foobar4
hmac_sha256(/test/apibar2foo1foo_bar3foobar4)
hex("helloworld".getBytes("utf-8")) = "68656C6C6F776F726C64"
Sample code for JAVA
/**
* Sign the API request with body.
*/
public static String signApiRequest(Map<String, String> params, String body, String appSecret, String signMethod, String apiName) throws IOException {
// first: sort all text parameters
String[] keys = params.keySet().toArray(new String[0]);
Arrays.sort(keys);
// second: connect all text parameters with key and value
StringBuilder query = new StringBuilder();
query.append(apiName);
for (String key : keys) {
String value = params.get(key);
if (areNotEmpty(key, value)) {
query.append(key).append(value);
}
}
// third：put the body to the end
if (body != null) {
query.append(body);
}
// next : sign the whole request
byte[] bytes = null;
if(signMethod.equals(Constants.SIGN_METHOD_HMAC)) {
bytes = encryptWithHmac(query.toString(), appSecret);
} else if(signMethod.equals(Constants.SIGN_METHOD_SHA256)) {
bytes = encryptHMACSHA256(query.toString(), appSecret);
}
// finally : transfer sign result from binary to upper hex string
return byte2hex(bytes);
}
private static byte[] encryptHMACSHA256(String data, String secret) throws IOException {
byte[] bytes = null;
try {
SecretKey secretKey = new SecretKeySpec(secret.getBytes(Constants.CHARSET_UTF8), Constants.SIGN_METHOD_HMAC_SHA256);
Mac mac = Mac.getInstance(secretKey.getAlgorithm());
mac.init(secretKey);
bytes = mac.doFinal(data.getBytes(Constants.CHARSET_UTF8));
} catch (GeneralSecurityException gse) {
throw new IOException(gse.toString());
}
return bytes;
}
/**
* Transfer binary array to HEX string.
*/
public static String byte2hex(byte[] bytes) {
StringBuilder sign = new StringBuilder();
for (int i = 0; i < bytes.length; i++) {
String hex = Integer.toHexString(bytes[i] & 0xFF);
if (hex.length() == 1) {
sign.append("0");
}
sign.append(hex.toUpperCase());
}
return sign.toString();
}
Sample code for C#
public static string SignRequest(IDictionary<string, string> parameters, string body, string appSecret, string signMethod, string apiName)
{
// first : sort all key with asci order
IDictionary<string, string> sortedParams = new SortedDictionary<string, string>(parameters, StringComparer.Ordinal);
// second : contact all params with key order
StringBuilder query = new StringBuilder();
query.Append(apiName);
foreach (KeyValuePair<string, string> kv in sortedParams)
{
if (!string.IsNullOrEmpty(kv.Key) && !string.IsNullOrEmpty(kv.Value))
{
query.Append(kv.Key).Append(kv.Value);
}
}
// third : add body to last
if (!string.IsNullOrEmpty(body))
{
query.Append(body);
}
// next : sign the string
byte[] bytes = null;
if (signMethod.Equals(Constants.SIGN_METHOD_SHA256))
{
HMACSHA256 sha256 = new HMACSHA256(Encoding.UTF8.GetBytes(appSecret));
bytes = sha256.ComputeHash(Encoding.UTF8.GetBytes(query.ToString()));
}
// finally : transfer binary byte to hex string
StringBuilder result = new StringBuilder();
for (int i = 0; i < bytes.Length; i++)
{
result.Append(bytes[i].ToString("X2"));
}
return result.ToString();
}
Sample code for PYTHON
def sign(secret,api, parameters):
#===========================================================================
# @param secret
# @param parameters
#===========================================================================
sort_dict = sorted(parameters)
parameters_str = "%s%s" % (api,
str().join('%s%s' % (key, parameters[key]) for key in sort_dict))
h = hmac.new(secret.encode(encoding="utf-8"), parameters_str.encode(encoding="utf-8"), digestmod=hashlib.sha256)
return h.hexdigest().upper()
For the signature sample codes in other programming languages, refer to the source code of the official SDK.
