This will upload an image to s3 from ios using the amazon library

uploadS3iOS.m

//#import <AWSS3/AWSS3.h>
//#import <AWSRuntime/AWSRuntime.h>
//import those in your .h file and
//add the awss3 and awsruntime framework from the client
//download from Amazon

        AmazonS3Client *s3Client = [[AmazonS3Client alloc] initWithAccessKey:@"Key_Goes_here" withSecretKey:@"Secret_Goes_Here"];

        NSString *imageName = [NSString stringWithFormat:@"%@.png", @"cpa"];

        S3PutObjectRequest *objReq = [[S3PutObjectRequest alloc] initWithKey:imageName inBucket:@"bucket_name"];
        objReq.contentType = @"image/png";
        objReq.cannedACL   = [S3CannedACL publicRead];
        objReq.data = UIImagePNGRepresentation(myFace);
        objReq.delegate = self;

        [s3Client putObject:objReq];