HTTP upload to S3 using Swift and Alamofire 4+

AmazonS3Upload.swift

class S3UploadCredentials: NSObject {
    var bucketUrl: String
    var key: String
    var acl: String
    var credential: String
    var date: String
    var algorithm: String
    var policy: String
    var signature: String
    var fileUrl: String

    init(bucketUrl: String, key: String, acl: String, credential: String, algorithm: String, date: String, policy: String, signature: String, fileUrl: String) {
        self.bucketUrl = bucketUrl
        self.key = key
        self.acl = acl
        self.credential = credential
        self.algorithm = algorithm
        self.date = date
        self.policy = policy
        self.signature = signature
        self.fileUrl = fileUrl
    }
}

// MARK: - S3
private func uploadImageToS3(image: UIImage, uploadCredentials s3: S3UploadCredentials, completion: @escaping ((Error?) -> ())) {
    let parameter = ["policy": s3.policy,
                     "x-amz-algorithm": s3.algorithm,
                     "x-amz-credential": s3.credential,
                     "x-amz-date": s3.date,
                     "x-amz-signature": s3.signature,
                     "key": s3.key,
                     "acl": s3.acl]

    guard let data = UIImageJPEGRepresentation(image, 1.0) else {
      let err = NSError(domain: "pl.appbeat", code: 9_999, userInfo: ["Data error": "Was not able to prepare image from data."])
      completion(err) // Provide a meaningful error for your app here
      return
    }

    Alamofire.upload(multipartFormData: { (multipartForm) in

        for (key, value) in parameter {

            multipartForm.append(value.data(using: .utf8)!, withName: key)

        }

        multipartForm.append(data, withName: "file")//, fileName: "file", mimeType: "image/jpeg")

    }, to: s3.bucketUrl, method : .put, headers: nil) { (encodingResult) in

        completion(nil)
        switch encodingResult {
        case .success(let upload, _, _):
            upload.responseData { response in
                switch response.result {
                case .success:
                    print(response.response!.statusCode)

                    if let data = response.data, let utf8Text = String(data: data, encoding: .utf8) {
                        print("Server Response: \(utf8Text)") // original server data as UTF8 string
                    }
                    break
                case .failure(let error):
                    print(response.response!.statusCode)
                    debugPrint(error)

                    break
                }
            }
        case .failure(let encodingError):
            print(encodingError)
        }
    }
}

Hello there,

I'm desperately trying to get this to work for me. Could you please Help Me?

Out of the following Headers:

let parameter = ["policy": s3.policy,
                     "x-amz-algorithm": s3.algorithm,
                     "x-amz-credential": s3.credential,
                     "x-amz-date": s3.date,
                     "x-amz-signature": s3.signature,
                     "key": s3.key,
                     "acl": s3.acl]

Could you please tell me where can I get: policy, key and acl?

Thank you very Much in advance!

Also, is the bucketUrl one with all the Query Params like this one showcased in the AWS Docs?

https://s3.amazonaws.com/examplebucket/test.txt
?X-Amz-Algorithm=AWS4-HMAC-SHA256
&X-Amz-Credential=AKIAIOSFODNN7EXAMPLE%2F20130524%2Fus-east-1%2Fs3%2Faws4_request
&X-Amz-Date=20130524T000000Z&X-Amz-Expires=86400&X-Amz-SignedHeaders=host
&X-Amz-Signature=<signature-value>

Thanks!

It's much simpler if you have a presigned-url. I couldn't get multi-part form to work as it was corrupting the file/image contents.

//data = UIImage.jpegData(...)
//url = presigned url
//method = needs to be same as what was used to generate presigned url

Alamofire
    .upload(data, to: url, method: .put)
    .responseString() { response in
        switch response.result {
        case .success:
            //success
        case .failure(let error):
            //failure
        }
    }