XAmzContentSHA256Mismatch using MBS Curls S3 upload example with Contabo

Add-Ons
1

I’m using the MBS sample projects for CURLS Amazon S3 download and upload projects to connect to S3 compatible cloud storage of Contabo (Contabo Cloud Object Storage).

https://www.monkeybreadsoftware.net/curl-curlmbs-shared-method.shtml

Download is working as expected, but upload throws an error:

<?xml version="1.0" encoding="UTF-8"?><Error><Code>XAmzContentSHA256Mismatch</Code><Message></Message><BucketName>nwscloudbackup</BucketName><RequestId>tx00000932f36a9b4a12da8-00673f4e84-199f7a4-eu2</RequestId><HostId>199f7a4-eu2-eu</HostId></Error>

I’m stuck here. Anybody has a clue how to overcome this error?
I could privat mail the modified upload project with current Contabo keys, for testing …

2

More debug data from the plugin:

MBS Xojo Plugins 21.3 with CURL 7.77.0 on macOS.

Trying 173.249.62.84:443…
Connected to eu2.contabostorage.com (173.249.62.84) port 443 (#0)
ALPN, offering http/1.1
TLSv1.3 (OUT), TLS handshake, Client hello (1):
TLSv1.3 (IN), TLS handshake, Server hello (2):
TLSv1.3 (IN), TLS handshake, Encrypted Extensions (8):
TLSv1.3 (IN), TLS handshake, Certificate (11):
TLSv1.3 (IN), TLS handshake, CERT verify (15):
TLSv1.3 (IN), TLS handshake, Finished (20):
TLSv1.3 (OUT), TLS change cipher, Change cipher spec (1):
TLSv1.3 (OUT), TLS handshake, Finished (20):
SSL connection using TLSv1.3 / TLS_AES_128_GCM_SHA256
ALPN, server did not agree to a protocol
Server certificate:
subject: CN=*.contabostorage.com
start date: Nov 14 00:00:00 2024 GMT
expire date: Feb 12 23:59:59 2025 GMT
issuer: C=AT; O=ZeroSSL; CN=ZeroSSL RSA Domain Secure Site CA
SSL certificate verify result: unable to get local issuer certificate (20), continuing anyway.
PUT /nwscloudbackup/test.png HTTP/1.1
Host: eu2.contabostorage.com
Authorization: AWS4-HMAC-SHA256 Credential=20b8dabcf0ac059091b4499e407417b1/20241121/eu-central-1/s3/aws4_request,SignedHeaders=host;x-amz-content-sha256;x-amz-date,Signature=1274e971f1c8922e3c9151e7b596b5c4eabded3249d51114d1518c66f671e23f
Date: Thu, 21 Nov 2024 15:31:37 GMT
x-amz-content-sha256: BEC4E802F22B31B3DD4C4DE4BD1966F6E389F7327506BD114B18CEB3C22BE84F
x-amz-date: 20241121T153137Z
Content-Length: 23266

We are completely uploaded and fine
TLSv1.3 (IN), TLS handshake, Newsession Ticket (4):
TLSv1.3 (IN), TLS handshake, Newsession Ticket (4):
old SSL session ID is stale, removing
Mark bundle as not supporting multiuse
HTTP/1.1 400 Bad Request
content-type: application/xml
content-length: 249
ratelimit-reset: 1
x-ratelimit-remaining-second: 249
x-ratelimit-limit-second: 250
ratelimit-limit: 250
ratelimit-remaining: 249
x-amz-request-id: tx000008bb8571337da3f59-00673f5259-19b6f8b-eu2
accept-ranges: bytes
date: Thu, 21 Nov 2024 15:31:38 GMT
access-control-allow-origin: *
access-control-expose-headers: *
strict-transport-security: max-age=16000000; includeSubDomains; preload;

Connection #0 to host eu2.contabostorage.com left intact

3

How do you make the upload?
The plugin calculates the hash. So do you put data in OptionPostfields or InputData properties?

4

I modified your CURLS example project for Amazon S3 upload:

Private Sub DoUpload()
  
  Dim e As Integer
  dim d as new UploadCURL
  
  Dim p As Picture = LogoMBS
  
  Dim file As FolderItem = SpecialFolder.Desktop.Child("test.png")
  Call d.OpenMTInputFile(file)
  
  //Contabo Cloud Storage
  Const AWSAccessKeyId = "20b8dabcf0ac059091b4499e*******"
  Const AWSSecretAccessKey = "b919da1c6204b9a30db5f*******"
  Const Region = "eu-central-1"
  Const Service = "s3"
  Const Domain = "eu2.contabostorage.com" // auto
  Const Verb = "PUT"
  Dim BucketName As String = "nwscloudbackup"
  Dim FileName As String = "test.png"
  Dim Path As String = "/" + BucketName + "/" + EncodeURLComponent(Filename)
  Dim HashedPayload As String // empty for auto
  
  
  HashedPayload = SHA256MBS.HashFile(file, True)
  
  call d.SetupAWS(AWSAccessKeyId, AWSSecretAccessKey, Region, Service, Path, Domain, Verb, HashedPayload)
  
  e=d.Perform
  
  listbox1.addrow "Result: "+str(e)
  
  dim DebugMessage as string = d.DebugData // check in debugger on error
  dim OutputData as string = d.OutputData
  dim HTTPResult as integer = d.GetInfoResponseCode
  if e <> 0 or HTTPResult <> 200 then
    break
  end if
  
  
End Sub
5

Could you try with LowerCase() for the HashedPayload?

I think our functions returns upper case, but AWS needs it lowercase.

1 Like
7

Yes, lowercase made it work! Thanks for the hint!

1 Like