/S3SignerAWS

Pure Swift AWS S3 Signer, generates V4 Auth Headers and V4 presignedURLs

Primary LanguageSwiftMIT LicenseMIT

S3SignerAWS

codecov Build Status CircleCI Codacy Badge Swift 4.0

Generates V4 authorization headers and pre-signed URLs for authenticating AWS S3 REST API calls

Check out VaporS3Signer if your using Vapor.

Features

  • Pure Swift
  • All required headers generated automatically
  • V4 Authorization header
  • V4 pre-signed URL
  • Support DELETE/GET/HEAD/PUT/POST
  • Single chunk uploads
  • Multiple chunk uploads

Table of Contents

Integration

Swift Package Manager

To install with swift package manager, add the package to your Package.swift file:

Import PackageDescription

  let package = Package(
    name: "Your_Project_Name",
    targets: [],
    dependencies: [
        .Package(url: "https://github.com/JustinM1/S3SignerAWS.git", majorVersion: 3)
    ]
  )

Usage

NOTE ABOUT PAYLOAD:

Requests can either have a signed payload or an unsigned payload.

  • S3SignerAWS is built using Vapor Server framework Crypto and uses Bytes as the payload data type. Bytes is a typealias of [UInt8] For example, to convert a data object to bytes you do the following:
let bytes = try someDataObject.makeBytes()

  • If you know the request will not have a payload, set the Payload property to none. This tells s3 that the signature was created with no payload intended

  • If you are not sure what the exact payload will be, set payload property to unsigned. This tells s3 when you made the signature, there was a possibility of a payload but you weren't sure what specific object will be uploaded.

  • Payload enum:

    public enum Payload {
  case bytes(Bytes)
  case none
  case unsigned
}

To begin working with the S3SignerAWS class, initialize an instance similar to example shown below:

let s3Signer = S3SignerAWS(accessKey: "YOUR_AWS_PUBLIC_KEY", secretKey: "YOUR_AWS_SECRET_KEY", region: .usStandard_usEast1)

NOTE - Hardcoding Secret Keys on client is not recommended for security reasons.

V4 Authorization Header

For both V4 Authorization Header and Pre-Signed URL, you can add additional headers as needed for your specific use case.

GET

do {
  guard let url = URL(string: "https://s3.amazonaws.com/bucketName/testUploadImage.png") else { throw someError }
  let headers = try s3Signer.authHeaderV4(httpMethod: .get, urlString: url.absoluteString, headers: [:], payload: .none)          
  var request = URLRequest(url: url)
  request.httpMethod = HTTPMethod.get.rawValue
  headers.forEach { request.setValue($0.key, forHTTPHeaderField: $0.value) }
      // make network request
    } catch {
      //handle error
    }
  }

PUT

do {
  let bytesObject = try someDataObject.makeBytes()
  guard let url = URL(string: "https://s3.amazonaws.com/bucketName/testUploadImage.png") else { throw someError }
  let headers = try s3Signer.authHeadersV4(httpMethod: .put, urlString: url.absoluteString, headers: [:], payload: .bytes(bytesObject))
  var request = URLRequest(url: url)
  request.httpMethod = HTTPMethod.put.rawValue
  request.httpBody = Data(bytes: bytesObject)
  headers.forEach { request.setValue($0.key, forHTTPHeaderField: $0.value) }
      // make network request
    } catch {
    //handle error
    }
  }

DELETE

do {
  guard let url = URL(string: "https://s3.amazonaws.com/bucketName/testUploadImage.png") else { throw someError }
  let headers = try s3Signer.authHeadersV4(httpMethod: .delete, urlString: url.absoluteString, headers: [:], payload: .none)
  var request = URLRequest(url: url)
  request.httpMethod = HTTPMethod.delete.rawValue
  headers.forEach { request.setValue($0.key, forHTTPHeaderField: $0.value) }
      // make network request
    } catch {
      //handle error
    }
  }

V4 Pre-Signed URL

Similar to the ease of generating authentication headers, to generate a pre-signed url:

let presignedURL = signer.presignedURLV4(httpMethod: HTTPMethod, urlString: String, expiration: TimeFromNow, headers: [String: String]) -> String