Handshake Exception when trying to upload a file using MultipartRequest in flutter - flutter

Question

I tried to upload a file to s3 using MultipartRequest in flutter but upon reach "response.send()" i get
I/flutter ( 8307): HandshakeException: Handshake error in client (OS Error:
I/flutter ( 8307): CERTIFICATE_VERIFY_FAILED: self signed certificate in certificate chain(handshake.cc:354))
I turned 'SSL Certificate Verification' off in Postman for it work, so is there any way to turn it off in flutter whilst uploading?
here is the code i used:
var request = http.MultipartRequest('POST', uri)
..fields['key'] = data.key
..fields['x-amz-algorithm'] = data.algorithm
..fields['x-amz-credential'] = data.credential
..fields['x-amz-date'] = data.date
..fields['x-amz-security-token'] = data.securityToken
..fields['policy'] = data.policy
..files.add(await http.MultipartFile.fromPath('File', imagePath, filename: imageName));
print(request.toString());
try {
var response = await request.send();
await for (var value in response.stream.transform(utf8.decoder)) {
print(value);
}
} catch (e) {
print(e.toString());
}

Answer 1

If anyone faces the same, I was able to fix the above issue using "Dio" package like so
Dio _client = Dio();
_client.interceptors.add(LogInterceptor());
FormData formData = FormData.fromMap({
'key': data.key,
'x-amz-algorithm': data.algorithm,
'x-amz-credential': data.credential,
'x-amz-date': data.date,
'x-amz-security-token': data.securityToken,
'policy': data.policy,
'x-amz-signature': data.signature,
'File': await MultipartFile.fromFile(
filePath,
filename: fileName,
)
});
(_client.httpClientAdapter as DefaultHttpClientAdapter).onHttpClientCreate =
(HttpClient dioClient) {
dioClient.badCertificateCallback =
(X509Certificate cert, String host, int port) => true;
return dio;
};
try {
await _client.post(
data.uploadUrl,
data: formData,
);
_client.close();
} catch (e) {
print(e.toString());
_client.close();
}