Aws iOS sdk Pre-singed url giving "SignatureDoesNotMatch" error - ios

Question

Have problem accessing file using presigned url generated by aws sdk, given all necessary permission for the bucket.
I have downloaded the sample code from there github and changed the below
Awscredential provider as per my requirement.
The changes are below
AWSStaticCredentialsProvider *credentialsProvider =[[AWSStaticCredentialsProvider alloc] initWithAccessKey:S3AccessKey secretKey:S3secretKey];
AWSServiceConfiguration *configuration = [[AWSServiceConfiguration alloc] initWithRegion:AWSRegionUSEast1 credentialsProvider:credentialsProvider];
AWSServiceManager.defaultServiceManager.defaultServiceConfiguration = configuration;
Even though i upload the file sucessfully to aws I am not able to access them using the presigned url which i get from the aws sdk while uploading.
Can anyone point out the things i am missing in order to access the files using presigned url.
when url is loaded in browser SignatureDoesNotMatch error is shown

Answer 1

The most possible reason for "SignatureDoesNotMatch" is the contents in header-field are different from the one provided while generating the presigned url.
Here is a code snippet to demonstrate how to generate and download a file by using presigned url:
AWSS3GetPreSignedURLRequest *getPreSignedURLRequest = [AWSS3GetPreSignedURLRequest new];
getPreSignedURLRequest.bucket = #"bucketname";
getPreSignedURLRequest.key = #"keyname";
getPreSignedURLRequest.HTTPMethod = AWSHTTPMethodGET;
getPreSignedURLRequest.expires = [NSDate dateWithTimeIntervalSinceNow:3600];
AWSS3PreSignedURLBuilder *preSignedURLBuilder = [AWSS3PreSignedURLBuilder defaultS3PreSignedURLBuilder];
[[[preSignedURLBuilder getPreSignedURL:getPreSignedURLRequest] continueWithBlock:^id(BFTask *task) {
if (task.error) {
XCTAssertNil(task.error);
return nil;
}
NSURL *presignedURL = task.result;
//NSLog(#"(GET)presigned URL is: %#",presignedURL.absoluteString);
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:presignedURL];
request.cachePolicy = NSURLRequestReloadIgnoringLocalCacheData;
NSError *returnError = nil;
NSHTTPURLResponse *returnResponse = nil;
NSData *responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:&returnResponse error:&returnError];
return nil;
}] waitUntilFinished];

Answer 2

The problem is with presigned url encoding. In iOS and android sdks (not in windows) you need to encode the query string in the Presigned url again.
NEWURL=baseurl +(encoded query String);
NEWURL is the correct url you can access.
it worked for me.

Answer 3

Try with this, you need to register PreSignedURL builder.
AWSStaticCredentialsProvider *credentialsProvider =[[AWSStaticCredentialsProvider alloc] initWithAccessKey:S3AccessKey secretKey:S3secretKey];
AWSServiceConfiguration *configuration = [[AWSServiceConfiguration alloc] initWithRegion:AWSRegionUSEast1 credentialsProvider:credentialsProvider];
AWSServiceManager.defaultServiceManager.defaultServiceConfiguration = configuration;
// Register S3 PreSignedURL Builder
[AWSS3PreSignedURLBuilder registerS3PreSignedURLBuilderWithConfiguration:configuration forKey:#"configuration_name"];
AWSS3PreSignedURLBuilder * urlBuilder = [AWSS3PreSignedURLBuilder S3PreSignedURLBuilderForKey:#"configuration_name"];