Received fatal alert: protocol_version

[engirah]

Hi

Am suddenly getting below error after using the dropbox API for over 3 years. No Change in Java code(Java 😎

Am using dropbox-core-sdk-3.0.5.jar library

Could be there is a change in SSL protocol?

Apr 19, 2022 9:24:16 AM downloads.Dropbox DownloadFile
INFO: null
com.dropbox.core.NetworkIOException: Received fatal alert: protocol_version
at com.dropbox.core.DbxRequestUtil.startPostRaw(DbxRequestUtil.java:245)
at com.dropbox.core.v2.DbxRawClientV2$2.execute(DbxRawClientV2.java:157)
at com.dropbox.core.v2.DbxRawClientV2$2.execute(DbxRawClientV2.java:152)
at com.dropbox.core.v2.DbxRawClientV2.executeRetriable(DbxRawClientV2.java:284)
at com.dropbox.core.v2.DbxRawClientV2.downloadStyle(DbxRawClientV2.java:152)
at com.dropbox.core.v2.files.DbxUserFilesRequests.download(DbxUserFilesRequests.java:884)
at com.dropbox.core.v2.files.DbxUserFilesRequests.download(DbxUserFilesRequests.java:913)
at downloads.Dropbox.DownloadFile(Dropbox.java:102)
at downloads.Dropbox.downloadFile(Dropbox.java:90)
at pointofsale.ui.settings.SysupdatesController.lambda$setListeners$8(SysupdatesController.java:171)

...........................

Caused by: javax.net.ssl.SSLException: Received fatal alert: protocol_version
at sun.security.ssl.Alerts.getSSLException(Alerts.java:208)
at sun.security.ssl.Alerts.getSSLException(Alerts.java:154)
at sun.security.ssl.SSLSocketImpl.recvAlert(SSLSocketImpl.java:2020)
at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1127)
at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1367)

[chek534]

I have the same problem.

[Greg-DB · Accepted solution]

Dropbox recently retired support for TLS 1.0 and 1.1. The Dropbox API servers now only support connections using TLS 1.2. You'll need to update your app/network client/environment to use TLS 1.2 in order to continue making Dropbox API calls.

It looks like you're using the Dropbox Java SDK, so to use TLS 1.2 you'll need to update to at least v3.1.1 of that SDK (or preferably, the latest version which is currently v5.2.0).

[chek534]

Greg-DB

I updated dropbox-core-sdk to 4.0.1 version and still received error:

  Received fatal alert: protocol_version

[Greg-DB]

@chek534 Make sure your platform itself also supports TLS v1.2. Some platforms/frameworks, especially older versions, may not have TLS v1.2 enabled. You may need to refer to your platform documentation for information on configuring that.

[engirah]

I updated dropbox-core-sdk to 4.0.1 version and worked perfectly
By default, java 1.8 use TSL1.2 as default
Thanks