A partir das informações fornecidas, parece que você adicionou o certificado do servidor ao seu arquivo /etc/ca-certificates . Você precisa adicionar o certificado de autoridade de certificação.
O comando openssl s_client -showcerts que você executou deveria ter incluído um ou mais outros certificados após o primeiro. Estes são aqueles com quem você se importa.
Se houver mais de um certificado após o primeiro, talvez seja necessário adicionar ambos ao seu arquivo ca-certificates . Tudo depende de como a autoridade de certificação está configurada no proxy. No entanto, se os dois não forem necessários, e você adicionar os dois de qualquer maneira, não vai doer.
No entanto, se o openssl s_client -showcerts não mostrar nenhum certificado além do primeiro, você estará em um riacho. Isso significa que o proxy não está enviando o certificado de assinatura. Você pode tentar entrar em contato com sua equipe de rede e perguntar por ela. Segurança, não há absolutamente nenhuma razão para eles não darem a você (é a chave que deve ser protegida).
Por exemplo, eu recebo o seguinte (sim, desde que eu não estou atrás de um proxy SSL, recebo os certificados reais, mas o conceito permanece):
# openssl s_client -showcerts -connect mirrors.kernel.org:443 CONNECTED(00000003) depth=2 C = US, O = "thawte, Inc.", OU = Certification Services Division, OU = "(c) 2006 thawte, Inc. - For authorized use only", CN = thawte Primary Root CA verify error:num=20:unable to get local issuer certificate verify return:0 --- Certificate chain 0 s:/C=US/ST=California/L=San Jose/O=The Linux Kernel Organization/CN=*.kernel.org i:/C=US/O=Thawte, Inc./CN=Thawte SSL CA -----BEGIN CERTIFICATE----- MIID2zCCAsOgAwIBAgIQZ7xPhWo7v0ZlPnI5mJWMazANBgkqhkiG9w0BAQUFADA8 MQswCQYDVQQGEwJVUzEVMBMGA1UEChMMVGhhd3RlLCBJbmMuMRYwFAYDVQQDEw1U aGF3dGUgU1NMIENBMB4XDTEyMDEwMzAwMDAwMFoXDTE0MDQwMzIzNTk1OVowdDEL MAkGA1UEBhMCVVMxEzARBgNVBAgTCkNhbGlmb3JuaWExETAPBgNVBAcUCFNhbiBK b3NlMSYwJAYDVQQKFB1UaGUgTGludXggS2VybmVsIE9yZ2FuaXphdGlvbjEVMBMG A1UEAxQMKi5rZXJuZWwub3JnMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKC AQEApSbajGUzM+C1Oz6CzyPmek9HH03ToicZeHxOlBfS7yyvIyybxTCBrmkItyc+ sf6b5g2Zf8IPwloaj+ACQaLfm0OOaFrvHERIN1t0pitvmeSDI6BXVYq0eSLEPpSG YC/3AMdKE21NO1jmL7mtsCB8CW4NAAvy97HkvsPsTPNOp6d/LtcIMYRS347RFgRj O/J1PU05EEjcpXdy6eCyJLwi2AFLgfBzjS+0UK4tq01HFalULfO/akjC59WG+qrc P/Yi/1TM8bE2mun1mcuCP7bmyZFDfrGnO2TYcZ/s7z4bTUmEixR6kTdj1foqi7Xk svko9dXCiUZj4c692ZKZXE+gJwIDAQABo4GgMIGdMAwGA1UdEwEB/wQCMAAwOgYD VR0fBDMwMTAvoC2gK4YpaHR0cDovL3N2ci1vdi1jcmwudGhhd3RlLmNvbS9UaGF3 dGVPVi5jcmwwHQYDVR0lBBYwFAYIKwYBBQUHAwEGCCsGAQUFBwMCMDIGCCsGAQUF BwEBBCYwJDAiBggrBgEFBQcwAYYWaHR0cDovL29jc3AudGhhd3RlLmNvbTANBgkq hkiG9w0BAQUFAAOCAQEAd7mKHpW1mCB1fGuvR44iX83PmSy3BVEpvOlnH1zNSU/Y 2zMmKDbXqAJTY6t20Yq/GpjW3BA2G4xEA6i64WAGZcSmXfc/NDOSh0i5lTrCofCG 3tuts9HTmHJLfeAz9cZiT4rc4ROMV4K17/Uw81UIid952M/4b6OvhaCu5OSnvDUI 3Z6OUy+AuJHbwEyB5bGOJ/mqVKUztgUK17bJiwDhwZ4Q8PT6YKUj5NgPcG6cUKxY HK6yxvoqH/s1DQJB3JHDSFVgY47ECmoHyQ5MvJN+naNrZJUIH0RTmmHNbQH772W7 m8I66jiDhXTd6+4v8DipvHJOSEv7ebG0Jf6gv7lc6w== -----END CERTIFICATE----- 1 s:/C=US/O=Thawte, Inc./CN=Thawte SSL CA i:/C=US/O=thawte, Inc./OU=Certification Services Division/OU=(c) 2006 thawte, Inc. - For authorized use only/CN=thawte Primary Root CA -----BEGIN CERTIFICATE----- MIIEbDCCA1SgAwIBAgIQTV8sNAiyTCDNbVB+JE3J7DANBgkqhkiG9w0BAQUFADCB qTELMAkGA1UEBhMCVVMxFTATBgNVBAoTDHRoYXd0ZSwgSW5jLjEoMCYGA1UECxMf Q2VydGlmaWNhdGlvbiBTZXJ2aWNlcyBEaXZpc2lvbjE4MDYGA1UECxMvKGMpIDIw MDYgdGhhd3RlLCBJbmMuIC0gRm9yIGF1dGhvcml6ZWQgdXNlIG9ubHkxHzAdBgNV BAMTFnRoYXd0ZSBQcmltYXJ5IFJvb3QgQ0EwHhcNMTAwMjA4MDAwMDAwWhcNMjAw MjA3MjM1OTU5WjA8MQswCQYDVQQGEwJVUzEVMBMGA1UEChMMVGhhd3RlLCBJbmMu MRYwFAYDVQQDEw1UaGF3dGUgU1NMIENBMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8A MIIBCgKCAQEAmeSFW3ZJfS8F2MWsyMip09yY5tc0pi8M8iIm2KPJFEyPBaRF6BQM WJAFGrfFwQalgK+7HUlrUjSIw1nn72vEJ0GMK2Yd0OCjl5gZNEtB1ZjVxwWtouTX 7QytT8G1sCH9PlBTssSQ0NQwZ2ya8Q50xMLciuiX/8mSrgGKVgqYMrAAI+yQGmDD 7bs6yw9jnw1EyVLhJZa/7VCViX9WFLG3YR0cB4w6LPf/gN45RdWvGtF42MdxaqMZ pzJQIenyDqHGEwNESNFmqFJX1xG0k4vlmZ9d53hR5U32t1m0drUJN00GOBN6HAiY XMRISstSoKn4sZ2Oe3mwIC88lqgRYke7EQIDAQABo4H7MIH4MDIGCCsGAQUFBwEB BCYwJDAiBggrBgEFBQcwAYYWaHR0cDovL29jc3AudGhhd3RlLmNvbTASBgNVHRMB Af8ECDAGAQH/AgEAMDQGA1UdHwQtMCswKaAnoCWGI2h0dHA6Ly9jcmwudGhhd3Rl LmNvbS9UaGF3dGVQQ0EuY3JsMA4GA1UdDwEB/wQEAwIBBjAoBgNVHREEITAfpB0w GzEZMBcGA1UEAxMQVmVyaVNpZ25NUEtJLTItOTAdBgNVHQ4EFgQUp6KDuzRFQD38 1TBPErk+oQGf9tswHwYDVR0jBBgwFoAUe1tFz6/Oy3r9MZIaarbzRutXSFAwDQYJ KoZIhvcNAQEFBQADggEBAIAigOBsyJUW11cmh/NyNNvGclYnPtOW9i4lkaU+M5en S+Uv+yV9Lwdh+m+DdExMU3IgpHrPUVFWgYiwbR82LMgrsYiZwf5Eq0hRfNjyRGQq 2HGn+xov+RmNNLIjv8RMVR2OROiqXZrdn/0Dx7okQ40tR0Tb9tiYyLL52u/tKVxp EvrRI5YPv5wN8nlFUzeaVi/oVxBw9u6JDEmJmsEj9cIqzEHPIqtlbreUgm0vQF9Y 3uuVK6ZyaFIZkSqudZ1OkubK3lTqGKslPOZkpnkfJn1h7X3S5XFV2JMXfBQ4MDzf huNMrUnjl1nOG5srztxl1Asoa06ERlFE9zMILViXIa4= -----END CERTIFICATE----- 2 s:/C=US/O=thawte, Inc./OU=Certification Services Division/OU=(c) 2006 thawte, Inc. - For authorized use only/CN=thawte Primary Root CA i:/C=ZA/ST=Western Cape/L=Cape Town/O=Thawte Consulting cc/OU=Certification Services Division/CN=Thawte Premium Server CA/[email protected] -----BEGIN CERTIFICATE----- MIIERTCCA66gAwIBAgIQM2VQCHmtc+IwueAdDX+skTANBgkqhkiG9w0BAQUFADCB zjELMAkGA1UEBhMCWkExFTATBgNVBAgTDFdlc3Rlcm4gQ2FwZTESMBAGA1UEBxMJ Q2FwZSBUb3duMR0wGwYDVQQKExRUaGF3dGUgQ29uc3VsdGluZyBjYzEoMCYGA1UE CxMfQ2VydGlmaWNhdGlvbiBTZXJ2aWNlcyBEaXZpc2lvbjEhMB8GA1UEAxMYVGhh d3RlIFByZW1pdW0gU2VydmVyIENBMSgwJgYJKoZIhvcNAQkBFhlwcmVtaXVtLXNl cnZlckB0aGF3dGUuY29tMB4XDTA2MTExNzAwMDAwMFoXDTIwMTIzMDIzNTk1OVow gakxCzAJBgNVBAYTAlVTMRUwEwYDVQQKEwx0aGF3dGUsIEluYy4xKDAmBgNVBAsT H0NlcnRpZmljYXRpb24gU2VydmljZXMgRGl2aXNpb24xODA2BgNVBAsTLyhjKSAy MDA2IHRoYXd0ZSwgSW5jLiAtIEZvciBhdXRob3JpemVkIHVzZSBvbmx5MR8wHQYD VQQDExZ0aGF3dGUgUHJpbWFyeSBSb290IENBMIIBIjANBgkqhkiG9w0BAQEFAAOC AQ8AMIIBCgKCAQEArKDw+4BZ1JzHpM+doVlzCRBFDA0sbmjxbFtIaElZN/wLMxnC d3/MEC2VNBzm600JpxzSuMmXNgK3idQkXwbAzESUlI0CYm/rWt0RjSiaXISQEHoN vXRmL2o4oOLVVETrHQefB7pv7un9Tgsp9T6EoAHxnKv4HH6JpOih2HFlDaNRe+68 0iJgDblbnd+6/FFbC6+Ysuku6QToYofeK8jXTsFMZB7dz4dYukpPymgHHRydSsbV L5HMfHFyHMXAZ+sy/cmSXJTahcCbv1N9Kwn0jJ2RH5dqUsveCTakd9h7h1BE1T5u KWn7OUkmHgmlgHtALevoJ4XJ/mH9fuZ8lx3VnQIDAQABo4HCMIG/MA8GA1UdEwEB /wQFMAMBAf8wOwYDVR0gBDQwMjAwBgRVHSAAMCgwJgYIKwYBBQUHAgEWGmh0dHBz Oi8vd3d3LnRoYXd0ZS5jb20vY3BzMA4GA1UdDwEB/wQEAwIBBjAdBgNVHQ4EFgQU e1tFz6/Oy3r9MZIaarbzRutXSFAwQAYDVR0fBDkwNzA1oDOgMYYvaHR0cDovL2Ny bC50aGF3dGUuY29tL1RoYXd0ZVByZW1pdW1TZXJ2ZXJDQS5jcmwwDQYJKoZIhvcN AQEFBQADgYEAhKhMyT4qvJrizI8LsiV3xGGJiWNa1KMVQNT7Xj+0Q+pjFytrmXSe Cajd1FYVLnp5MV9jllMbNNkV6k9tcMq+9oKp7dqFd8x2HGqBCiHYQZl/Xi6Cweiq 95OBBaqStB+3msAHF/XLxrRMDtdW3HEgdDjWdMbWj2uvi42gbCkLYeA= -----END CERTIFICATE----- --- Server certificate subject=/C=US/ST=California/L=San Jose/O=The Linux Kernel Organization/CN=*.kernel.org issuer=/C=US/O=Thawte, Inc./CN=Thawte SSL CA --- No client certificate CA names sent --- SSL handshake has read 3566 bytes and written 636 bytes --- New, TLSv1/SSLv3, Cipher is RC4-SHA Server public key is 2048 bit Secure Renegotiation IS supported Compression: NONE Expansion: NONE SSL-Session: Protocol : TLSv1 Cipher : RC4-SHA Session-ID: EAB5C93513AA8829036C7BB9E3F74D99076C8A339EB220832F76DF73D52D0B22 Session-ID-ctx: Master-Key: 0A599E2D1CCAA8249E50871FDF03A2137BA034BCB20FA691D1413822BE08E15303CB0F59CDEC0376D670E08632EF0D46 Key-Arg : None PSK identity: None PSK identity hint: None SRP username: None TLS session ticket: 0000 - ac 28 d2 81 da 5e b9 7f-43 52 ab e8 2c b0 ac 1d .(...^..CR..,... 0010 - c0 27 92 cb 5e 0e 1e 36-e4 77 34 bf 34 f8 cb 2f .'..^..6.w4.4../ 0020 - 04 af 1a 9b ea b3 9e 6f-32 44 4b ce d1 b4 2b 42 .......o2DK...+B 0030 - 55 a8 e3 ec 9a 6a 76 5d-c0 84 e0 aa 20 29 ae ac U....jv].... ).. 0040 - 7d 45 2b 3b 56 3c 2e 4b-d3 69 60 c8 fb 67 36 07 }E+;V...;.]p....... 00a0 - de 09 7d bf 3f b9 2c 9c-af 5d b1 af b2 9b bc 7a ..}.?.,..].....z 00b0 - 5e b3 92 26 02 3a 0e 47-c9 4b 10 6c 5b f4 2f c3 ^..&.:.G.K.l[./. Start Time: 1380663897 Timeout : 300 (sec) Verify return code: 20 (unable to get local issuer certificate) ---
Eu adicionaria o certificado 2, o (último). Eu não precisaria do certificado 1, pois é um certificado de cadeia e está autorizado a ser um certificado de cadeia pelo certificado 2. No entanto, eu também poderia adicionar o certificado 1 e não prejudicaria.