sslopensslftpftpsvsftpd

How do I configure vsftpd and openssl to avoid TLS unsupported protocol error with Sony Camera

I have a Sony a7iii camera that I'm trying to connect to a self-hosted vsftpd server. Connection works fine in FTP (unencrypted) mode but fails when I switch to encrypted mode per the log readout below. Have already followed the guide to prepare the camera from Sony's website. Server is running Debian 10 with vsftpd 3.0.3 and openssl 1.1.1d. Connection from FileZilla on a different client works fine.

vsftpd.log

Mon Dec 14 23:54:20 2020 [pid 465] CONNECT: Client "::ffff:192.168.40.92"
Mon Dec 14 23:54:20 2020 [pid 465] FTP response: Client "::ffff:192.168.40.92", "220 (vsFTPd 3.0.3)"
Mon Dec 14 23:54:20 2020 [pid 465] FTP command: Client "::ffff:192.168.40.92", "AUTH TLS"
Mon Dec 14 23:54:20 2020 [pid 465] FTP response: Client "::ffff:192.168.40.92", "234 Proceed with negotiation."
Mon Dec 14 23:54:20 2020 [pid 465] DEBUG: Client "::ffff:192.168.40.92", "SSL_accept failed: error:14209102:SSL routines:tls_early_post_process_client_hello:unsupported protocol"

vsftpd.conf

listen=NO
listen_ipv6=YES
anonymous_enable=NO
local_enable=YES
write_enable=YES
dirmessage_enable=YES
use_localtime=YES
xferlog_enable=YES
connect_from_port_20=YES
xferlog_std_format=NO
log_ftp_protocol=YES
debug_ssl=YES
secure_chroot_dir=/var/run/vsftpd/empty
pam_service_name=vsftpd

rsa_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem
rsa_private_key_file=/etc/ssl/private/ssl-cert-snakeoil.key
ssl_enable=YES
allow_anon_ssl=NO
ssl_ciphers=HIGH:AES256-SHA:!aNULL
ssl_tlsv1=YES

local_root=(removed)

pasv_enable=YES
pasv_max_port=3050
pasv_min_port=3000

I found a Reddit user with a similar problem but implementing his solution of adding ssl_ciphers to the config does not seem to fix this for me.

When I do a tcpdump on the server and import into Wireshark I see a Client Hello followed by a fatal error response due to protocol version:

Wireshark [camera --> vsftpd]: TLSv1 Client Hello

TLSv1 Record Layer: Handshake Protocol: Client Hello
    Content Type: Handshake (22)
    Version: TLS 1.0 (0x0301)
    Length: 66
    Handshake Protocol: Client Hello
        Handshake Type: Client Hello (1)
        Length: 62
        Version: TLS 1.0 (0x0301)
        Random: cf73dfbf790af4cee34aba8c0b4f4b00db4f7e14eb06ceebd8278c874e0abf6a
        Session ID Length: 0
        Cipher Suites Length: 16
        Cipher Suites (8 suites)
            Cipher Suite: TLS_DHE_RSA_WITH_AES_256_CBC_SHA (0x0039)
            Cipher Suite: TLS_DHE_DSS_WITH_AES_256_CBC_SHA (0x0038)
            Cipher Suite: TLS_RSA_WITH_AES_256_CBC_SHA (0x0035)
            Cipher Suite: TLS_DHE_RSA_WITH_AES_128_CBC_SHA (0x0033)
            Cipher Suite: TLS_DHE_DSS_WITH_AES_128_CBC_SHA (0x0032)
            Cipher Suite: TLS_RSA_WITH_AES_128_CBC_SHA (0x002f)
            Cipher Suite: TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA (0x0013)
            Cipher Suite: TLS_EMPTY_RENEGOTIATION_INFO_SCSV (0x00ff)
        Compression Methods Length: 1
        Compression Methods (1 method)
            Compression Method: null (0)
        Extensions Length: 5
        Extension: heartbeat (len=1)
            Type: heartbeat (15)
            Length: 1
            Mode: Peer allowed to send requests (1)

Wireshark [vsftpd --> camera]: TLSv1 Alert (Level: Fatal, Description: Protocol Version)

TLSv1 Record Layer: Alert (Level: Fatal, Description: Protocol Version)
    Content Type: Alert (21)
    Version: TLS 1.0 (0x0301)
    Length: 2
    Alert Message
        Level: Fatal (2)
        Description: Protocol Version (70)

Result of openssl ciphers -v -tls1

TLS_AES_256_GCM_SHA384  TLSv1.3 Kx=any      Au=any  Enc=AESGCM(256) Mac=AEAD
TLS_CHACHA20_POLY1305_SHA256 TLSv1.3 Kx=any      Au=any  Enc=CHACHA20/POLY1305(256) Mac=AEAD
TLS_AES_128_GCM_SHA256  TLSv1.3 Kx=any      Au=any  Enc=AESGCM(128) Mac=AEAD
ECDHE-ECDSA-AES256-GCM-SHA384 TLSv1.2 Kx=ECDH     Au=ECDSA Enc=AESGCM(256) Mac=AEAD
ECDHE-RSA-AES256-GCM-SHA384 TLSv1.2 Kx=ECDH     Au=RSA  Enc=AESGCM(256) Mac=AEAD
DHE-RSA-AES256-GCM-SHA384 TLSv1.2 Kx=DH       Au=RSA  Enc=AESGCM(256) Mac=AEAD
ECDHE-ECDSA-CHACHA20-POLY1305 TLSv1.2 Kx=ECDH     Au=ECDSA Enc=CHACHA20/POLY1305(256) Mac=AEAD
ECDHE-RSA-CHACHA20-POLY1305 TLSv1.2 Kx=ECDH     Au=RSA  Enc=CHACHA20/POLY1305(256) Mac=AEAD
DHE-RSA-CHACHA20-POLY1305 TLSv1.2 Kx=DH       Au=RSA  Enc=CHACHA20/POLY1305(256) Mac=AEAD
ECDHE-ECDSA-AES128-GCM-SHA256 TLSv1.2 Kx=ECDH     Au=ECDSA Enc=AESGCM(128) Mac=AEAD
ECDHE-RSA-AES128-GCM-SHA256 TLSv1.2 Kx=ECDH     Au=RSA  Enc=AESGCM(128) Mac=AEAD
DHE-RSA-AES128-GCM-SHA256 TLSv1.2 Kx=DH       Au=RSA  Enc=AESGCM(128) Mac=AEAD
ECDHE-ECDSA-AES256-SHA384 TLSv1.2 Kx=ECDH     Au=ECDSA Enc=AES(256)  Mac=SHA384
ECDHE-RSA-AES256-SHA384 TLSv1.2 Kx=ECDH     Au=RSA  Enc=AES(256)  Mac=SHA384
DHE-RSA-AES256-SHA256   TLSv1.2 Kx=DH       Au=RSA  Enc=AES(256)  Mac=SHA256
ECDHE-ECDSA-AES128-SHA256 TLSv1.2 Kx=ECDH     Au=ECDSA Enc=AES(128)  Mac=SHA256
ECDHE-RSA-AES128-SHA256 TLSv1.2 Kx=ECDH     Au=RSA  Enc=AES(128)  Mac=SHA256
DHE-RSA-AES128-SHA256   TLSv1.2 Kx=DH       Au=RSA  Enc=AES(128)  Mac=SHA256
ECDHE-ECDSA-AES256-SHA  TLSv1 Kx=ECDH     Au=ECDSA Enc=AES(256)  Mac=SHA1
ECDHE-RSA-AES256-SHA    TLSv1 Kx=ECDH     Au=RSA  Enc=AES(256)  Mac=SHA1
DHE-RSA-AES256-SHA      SSLv3 Kx=DH       Au=RSA  Enc=AES(256)  Mac=SHA1
ECDHE-ECDSA-AES128-SHA  TLSv1 Kx=ECDH     Au=ECDSA Enc=AES(128)  Mac=SHA1
ECDHE-RSA-AES128-SHA    TLSv1 Kx=ECDH     Au=RSA  Enc=AES(128)  Mac=SHA1
DHE-RSA-AES128-SHA      SSLv3 Kx=DH       Au=RSA  Enc=AES(128)  Mac=SHA1
RSA-PSK-AES256-GCM-SHA384 TLSv1.2 Kx=RSAPSK   Au=RSA  Enc=AESGCM(256) Mac=AEAD
DHE-PSK-AES256-GCM-SHA384 TLSv1.2 Kx=DHEPSK   Au=PSK  Enc=AESGCM(256) Mac=AEAD
RSA-PSK-CHACHA20-POLY1305 TLSv1.2 Kx=RSAPSK   Au=RSA  Enc=CHACHA20/POLY1305(256) Mac=AEAD
DHE-PSK-CHACHA20-POLY1305 TLSv1.2 Kx=DHEPSK   Au=PSK  Enc=CHACHA20/POLY1305(256) Mac=AEAD
ECDHE-PSK-CHACHA20-POLY1305 TLSv1.2 Kx=ECDHEPSK Au=PSK  Enc=CHACHA20/POLY1305(256) Mac=AEAD
AES256-GCM-SHA384       TLSv1.2 Kx=RSA      Au=RSA  Enc=AESGCM(256) Mac=AEAD
PSK-AES256-GCM-SHA384   TLSv1.2 Kx=PSK      Au=PSK  Enc=AESGCM(256) Mac=AEAD
PSK-CHACHA20-POLY1305   TLSv1.2 Kx=PSK      Au=PSK  Enc=CHACHA20/POLY1305(256) Mac=AEAD
RSA-PSK-AES128-GCM-SHA256 TLSv1.2 Kx=RSAPSK   Au=RSA  Enc=AESGCM(128) Mac=AEAD
DHE-PSK-AES128-GCM-SHA256 TLSv1.2 Kx=DHEPSK   Au=PSK  Enc=AESGCM(128) Mac=AEAD
AES128-GCM-SHA256       TLSv1.2 Kx=RSA      Au=RSA  Enc=AESGCM(128) Mac=AEAD
PSK-AES128-GCM-SHA256   TLSv1.2 Kx=PSK      Au=PSK  Enc=AESGCM(128) Mac=AEAD
AES256-SHA256           TLSv1.2 Kx=RSA      Au=RSA  Enc=AES(256)  Mac=SHA256
AES128-SHA256           TLSv1.2 Kx=RSA      Au=RSA  Enc=AES(128)  Mac=SHA256
ECDHE-PSK-AES256-CBC-SHA384 TLSv1 Kx=ECDHEPSK Au=PSK  Enc=AES(256)  Mac=SHA384
ECDHE-PSK-AES256-CBC-SHA TLSv1 Kx=ECDHEPSK Au=PSK  Enc=AES(256)  Mac=SHA1
SRP-RSA-AES-256-CBC-SHA SSLv3 Kx=SRP      Au=RSA  Enc=AES(256)  Mac=SHA1
SRP-AES-256-CBC-SHA     SSLv3 Kx=SRP      Au=SRP  Enc=AES(256)  Mac=SHA1
RSA-PSK-AES256-CBC-SHA384 TLSv1 Kx=RSAPSK   Au=RSA  Enc=AES(256)  Mac=SHA384
DHE-PSK-AES256-CBC-SHA384 TLSv1 Kx=DHEPSK   Au=PSK  Enc=AES(256)  Mac=SHA384
RSA-PSK-AES256-CBC-SHA  SSLv3 Kx=RSAPSK   Au=RSA  Enc=AES(256)  Mac=SHA1
DHE-PSK-AES256-CBC-SHA  SSLv3 Kx=DHEPSK   Au=PSK  Enc=AES(256)  Mac=SHA1
AES256-SHA              SSLv3 Kx=RSA      Au=RSA  Enc=AES(256)  Mac=SHA1
PSK-AES256-CBC-SHA384   TLSv1 Kx=PSK      Au=PSK  Enc=AES(256)  Mac=SHA384
PSK-AES256-CBC-SHA      SSLv3 Kx=PSK      Au=PSK  Enc=AES(256)  Mac=SHA1
ECDHE-PSK-AES128-CBC-SHA256 TLSv1 Kx=ECDHEPSK Au=PSK  Enc=AES(128)  Mac=SHA256
ECDHE-PSK-AES128-CBC-SHA TLSv1 Kx=ECDHEPSK Au=PSK  Enc=AES(128)  Mac=SHA1
SRP-RSA-AES-128-CBC-SHA SSLv3 Kx=SRP      Au=RSA  Enc=AES(128)  Mac=SHA1
SRP-AES-128-CBC-SHA     SSLv3 Kx=SRP      Au=SRP  Enc=AES(128)  Mac=SHA1
RSA-PSK-AES128-CBC-SHA256 TLSv1 Kx=RSAPSK   Au=RSA  Enc=AES(128)  Mac=SHA256
DHE-PSK-AES128-CBC-SHA256 TLSv1 Kx=DHEPSK   Au=PSK  Enc=AES(128)  Mac=SHA256
RSA-PSK-AES128-CBC-SHA  SSLv3 Kx=RSAPSK   Au=RSA  Enc=AES(128)  Mac=SHA1
DHE-PSK-AES128-CBC-SHA  SSLv3 Kx=DHEPSK   Au=PSK  Enc=AES(128)  Mac=SHA1
AES128-SHA              SSLv3 Kx=RSA      Au=RSA  Enc=AES(128)  Mac=SHA1
PSK-AES128-CBC-SHA256   TLSv1 Kx=PSK      Au=PSK  Enc=AES(128)  Mac=SHA256
PSK-AES128-CBC-SHA      SSLv3 Kx=PSK      Au=PSK  Enc=AES(128)  Mac=SHA1

How can I get past this error? Am I missing something? I see AES256-SHA listed among other common ciphers that could be negotiated. TLS 1.0 is enabled and referenced in both the Client Hello and the server response. I don't understand why I'm having this issue. Any ideas?

Solution 
  • ssl_ciphers=HIGH:AES256-SHA:!aNULL

    By default Debian 10 uses the security level 2 which disables TLS 1.0. Try to set the ciphers to 'HIGH:@SECLEVEL=1' in order to allow TLS 1.0.