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OpenSSL v1.1.1 Ubuntu 20 TLSv1 - no protocols available

In Ubuntu 20.04, through a VPN, I can no longer access a server, which uses the TLSv1 protocol.

In Ubuntu 18.04, it was working.

First I connect to the VPN via SNX and then I use a program that accesses the server.

I did some tests with openssl to highlight this problem. Is it possible to solve this? I believe that my problem may have to do with the same reported at https://github.com/curl/curl/issues/4097.

I think OpenSSL v1.1.1 ssl_choose_client_version unsupported protocol has to do with my problem, but it's different because it doesn't have the problem "no protocols available".

When I test with openssl, I get the error "unsupported protocol", but when I test with openssl forcing TLSv1 I get the error "no protocols available".

Details of the tests:

Ubuntu 18.04:

Package: openssl
-> Version: 1.1.1-1ubuntu2.1 ~ 18.04.5

openssl s_client -connect host: port
-> works - TLSv1 ("SSL-Session: Protocol: TLSv1.").

openssl s_client -connect host: port -tls1
-> works - TLSv1 ("SSL-Session: Protocol: TLSv1.").

openssl s_client -connect host: port -tls1_1
-> 139786161414592: error: 1425F102: SSL routines: ssl_choose_client_version: unsupported protocol: ../ ssl / statem / statem_lib.c: 1907:

openssl s_client -connect host: port -tls1_2
-> 139786161414592: error: 1425F102: SSL routines: ssl_choose_client_version: unsupported protocol: ../ ssl / statem / statem_lib.c: 1907:

Ubuntu 20.04:

Package: openssl
-> Version: 1.1.1f-1ubuntu2

openssl s_client -connect host: port
-> 140253162648896: error: 1425F102: SSL routines: ssl_choose_client_version: unsupported protocol: ../ ssl / statem / statem_lib.c: 1941:

openssl s_client -connect host: port -tls1
-> 139722831217984: error: 141E70BF: SSL routines: tls_construct_client_hello: no protocols available: ../ ssl / statem / statem_clnt.c: 1112:

openssl s_client -connect host: port -tls1_1
-> 139923839911232: error: 141E70BF: SSL routines: tls_construct_client_hello: no protocols available: ../ ssl / statem / statem_clnt.c: 1112:

openssl s_client -connect host: port -tls1_2
-> 139862992581952: error: 1425F102: SSL routines: ssl_choose_client_version: unsupported protocol: ../ ssl / statem / statem_lib.c: 1941:

Ubuntu 18.04 - Successfully detailed connection

my@machine: ~ $ openssl s_client -connect my.domain: 9023 -tls1
CONNECTED (00000005)
depth = 2 C = XX, O = XXXXXX, OU = ICP-XX, CN = AC XXXXX vX
verify error: num = 19: self signed certificate in certificate chain
---
Certificate chain
 0 s: C = XX, ST = XX, L = XXXXXX, O = XXXXXXXX, OU = XXXXXXXXXXX XXXXX, CN = xxx.com
   i: C = XX, O = XXXXXXXX., OU = ICP-XX, CN = AC XXXXX vX
 1 s: C = XX, O = XXXXXXXX., OU = ICP-XX, CN = AC XXXXX vX
   i: C = XX, O = XXXXXXXX., OU = ICP-XX, CN = AC XXXXX vX
 2 s: C = XX, O = XXXXXXXX., OU = ICP-XX, CN = AC XXXXX vX
   i: C = XX, O = XXXXXXXX., OU = ICP-XX, CN = AC XXXXX vX
---
Server certificate
----- BEGIN CERTIFICATE -----
(...)
-----END CERTIFICATE-----
subject=X = XX, ST = XX, L = XXXXXX, O = XXXXXXX, OU = XXXXXXXX, CN = mydomain.com

issuer=C = XX, O = XXXXXXXXXX, OU = ICP-XX, CN = AC XXXXXXXXXXXXXXXXXXXXX

---
No client certificate CA names sent
---
SSL handshake has read 4604 bytes and written 449 bytes
Verification error: self signed certificate in certificate chain
---
New, SSLv3, Cipher is AES256-SHA
Server public key is 2048 bit
Secure Renegotiation IS supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
SSL-Session:
    Protocol: TLSv1
    Cipher: AES256-SHA
    Session-ID: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
    Session-ID-ctx:
    Master-Key: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
    PSK identity: None
    PSK identity hint: None
    SRP username: None
    Start Time: 1588445847
    Timeout: 7200 (sec)
    Verify return code: 19 (self signed certificate in certificate chain)
    Extended master secret: no
---

Ubuntu 20.04 - Detailed unsuccessful connection:

my@machine: ~ / Documents / $ openssl s_client -connect my.domain: 9023
CONNECTED (00000003)
139912319178048: error: 1425F102: SSL routines: ssl_choose_client_version: unsupported protocol: ../ ssl / statem / statem_lib.c: 1941:
---
no peer certificate available
---
No client certificate CA names sent
---
SSL handshake has read 4545 bytes and written 309 bytes
Verification: OK
---
New, (NONE), Cipher is (NONE)
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
Early data was not sent
Verify return code: 0 (ok)
---

my@machine: ~ / Documents / study $ openssl s_client -connect my.domain: 9023 -tls1
CONNECTED (00000003)
140581447836992: error: 141E70BF: SSL routines: tls_construct_client_hello: no protocols available: ../ ssl / statem / statem_clnt.c: 1112:
-
Solution

  • I've just solved my problem with - https://askubuntu.com/questions/1233186/ubuntu-20-04-how-to-set-lower-ssl-security-level

    Just quoting this link:

    You need to add this to the beginning of your config file:

    openssl_conf = default_conf

    And then this to the end:

    [ default_conf ]

ssl_conf = ssl_sect

[ssl_sect]

system_default = ssl_default_sect

[ssl_default_sect]
MinProtocol = TLSv1
CipherString = DEFAULT:@SECLEVEL=1

    The comment on the above link said:

    Note that if you prefer you can make changes to a local copy of the config file, and then ensure your process is started with the environment variable OPENSSL_CONF defined to point at the location of your config file:

export OPENSSL_CONF=/path/to/my/openssl.cnf

This way you can make changes without having to impact your entire system.

    I used the second choice "export OPENSSL_CONF=/path/to/my/openssl.cnf" and worked perfectly!