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Question:

What ciphers does version FTP2 9.5.0.21 support ?

Aug 15 '15 at 18:27

We have the above version of FTP2 we are reducing the ciphers on our Secure server to address the logjam issue. When testing we fail. We have reduced to two ciphers, TLS_RSA_WITH_AES_128_CBC_SHA256 and TLS_RSA_WITH_AES_256_CBC_SHA265

Here is the last of the log

 --LocalMachineRootCertStore
      --cacheClientCerts
      clientHandshake2:
        processAlert:
          TlsAlert:
            level: fatal
            descrip: handshake failure
          --TlsAlert
          passiveClose:
            Passive socket closing complete.
          --passiveClose
        --processAlert
        Failed to read incoming handshake messages. (1)
      --clientHandshake2
    --clientHandshake
    Client handshake failed. (1)
    connectionClosed: 0
  --convertToTls
  Failed to convert channel to SSL/TLS
--authTls
Failed to connect to FTP server.
Failed.

--Connect_Ftp2 --ChilkatLog 220-DMV Secure File Transfer

220- 220- 220 Secure FTP Server ready. AUTH TLS 234 SSLv23/TLSv1 ChilkatLog: ChangeRemoteDir:

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Answer

Thanks, I was working on reducing ciphers for PCI compliance, thru hunt and peck I was able to find an allowable combination.

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Answer

Not sure about 9.5.0.21, but the current documentation mentions that as of 9.5.0.48 the following about supported ciphers. Dees it help?

SslAllowedCiphers As String

Introduced in version 9.5.0.48

Provides a means for setting a list of ciphers that are allowed for SSL/TLS connections. The default (empty string) indicates that all implemented ciphers are possible: aes256-cbc, aes128-cbc, 3des-cbc, and rc4. To restrict SSL/TLS connections to one or more specific ciphers, set this property to a comma-separated list of ciphers such as "aes256-cbc, aes128-cbc". The order should be in terms of preference, with the preferred algorithms listed first. The server however, chooses from among the algorithms listed.

Starting in v9.5.0.48, Chilkat will by-default disallow all possible usage of RSA keys that are less than 1024 bits. To allow for 512 bits or above, add "rsa512" to the list of algorithms in the SslAllowedCiphers list. To allow only 2048 bits or above, add "rsa2048" to the list of algorithms. (Adding "rsa1024" chooses the same as the default.)