{"id":2279,"date":"2025-03-15T12:30:00","date_gmt":"2025-03-15T17:30:00","guid":{"rendered":"https:\/\/linuxhostsupport.com\/blog\/?p=2279"},"modified":"2025-01-22T05:28:44","modified_gmt":"2025-01-22T11:28:44","slug":"openssl-s_client-commands-to-test-ssl-connectivity","status":"publish","type":"post","link":"https:\/\/linuxhostsupport.com\/blog\/openssl-s_client-commands-to-test-ssl-connectivity\/","title":{"rendered":"Using OpenSSL s_client commands to test SSL connectivity"},"content":{"rendered":"\n
\"\"<\/a><\/div>

OpenSSL is an open-source software library that provides cryptographic functions and tools for secure communication over computer networks. It supports implementing the Secure Sockets Layer (SSL) and Transport Layer Security (TLS) protocols, essential for encrypting data transmitted over the Internet and ensuring confidentiality, integrity, and authentication. OpenSSL comes preinstalled on almost all Linux distributions. In this tutorial, you will learn how to use the OpenSSL s_client tool to test SSL\/TLS connections \u2014 using OpenSSL s_client to test SSL connections.<\/p>\n\n\n\n\n\n\n\n

Test SSL connection with OpenSSL s_client command<\/h2>\n\n\n\n

OpenSSL s_client is a diagnostic tool provided by OpenSSL. It allows users to connect to a remote server over SSL\/TLS and includes detailed information about the connection, including the server’s certificate and cipher suite used.
You can use the s_client tool in the following manner:<\/p>\n\n\n\n

$ openssl s_client -connect <URL>:<port><\/code><\/pre>\n\n\n\n
For example, let\u2019s check the SSL connection to https:\/\/google.com. You can do this by using the command:<\/p>\n\n\n\n
$ openssl s_client -connect google.com:443<\/code><\/pre>\n\n\n\n
And you should get a similar output:<\/p>\n\n\n\n
CONNECTED(00000003)\ndepth=2 C = US, O = Google Trust Services LLC, CN = GTS Root R1\nverify return:1\ndepth=1 C = US, O = Google Trust Services, CN = WR2\nverify return:1\ndepth=0 CN = *.google.com\n\nverify return:1\n\nCertificate chain\n0 s:CN = *.google.com\ni:C = US, O = Google Trust Services, CN = WR2\na:PKEY: id-ecPublicKey, 256 (bit); sigalg: RSA-SHA256\nv:NotBefore: Dec 9 08:36:18 2024 GMT; NotAfter: Mar 3 08:36:17 2025 GMT\n1 s:C = US, O = Google Trust Services, CN = WR2\ni:C = US, O = Google Trust Services LLC, CN = GTS Root R1\na:PKEY: rsaEncryption, 2048 (bit); sigalg: RSA-SHA256\nv:NotBefore: Dec 13 09:00:00 2023 GMT; NotAfter: Feb 20 14:00:00 2029 GMT\n2 s:C = US, O = Google Trust Services LLC, CN = GTS Root R1\ni:C = BE, O = GlobalSign nv-sa, OU = Root CA, CN = GlobalSign Root CA\na:PKEY: rsaEncryption, 4096 (bit); sigalg: RSA-SHA256\n\nv:NotBefore: Jun 19 00:00:42 2020 GMT; NotAfter: Jan 28 00:00:42 2028 GMT\n\nServer certificate\n-----BEGIN CERTIFICATE-----\nMIIOCjCCDPKgAwIBAgIRANERcBmQhxEWCf0Wha+2dDQwDQYJKoZIhvcNAQELBQAw\n\u2026\nv6UcZPB82aISNkLMOnYM\/13lklT3rQfSxiarKoFrunjLpmqXLm8OfgJ9XwkZ+i9e\n7ACEhRhCjV8aYBkZ7lkeXbtDbpN6em2O6XqavyQKfDM7S5w7PEJbKosliVRKeCSB\nDrRUt75eDiWKq4X2C+CUWFiTaaEttI2r3G4GmqIwVuDl60STgMxTOuZKGbJDAQ==\n-----END CERTIFICATE-----\nsubject=CN = *.google.com\n\nissuer=C = US, O = Google Trust Services, CN = WR2\n\nNo client certificate CA names sent\nPeer signing digest: SHA256\nPeer signature type: ECDSA\n\nServer Temp Key: X25519, 253 bits\n\nSSL handshake has read 6590 bytes and written 392 bytes\n\nVerification: OK\n\nNew, TLSv1.3, Cipher is TLS_AES_256_GCM_SHA384\nServer public key is 256 bit\nSecure Renegotiation IS NOT supported\nCompression: NONE\nExpansion: NONE\nNo ALPN negotiated\nEarly data was not sent\n\nVerify return code: 0 (ok)\n\nPost-Handshake New Session Ticket arrived:\nSSL-Session:\nProtocol : TLSv1.3\nCipher : TLS_AES_256_GCM_SHA384\nSession-ID: 7E47DEC5B5929FD153E9D4E21BAA9B44D67E1FD936B451AD7440066780AF9CD6\nSession-ID-ctx:\nResumption PSK: 294249B6752F0A655E26B1E4A21FC364223CBBEFCFE083FD811DD445E9A8B16D067DB419E5C729778EB04FEE18FCF9D0\nPSK identity: None\nPSK identity hint: None\nSRP username: None\nTLS session ticket lifetime hint: 172799 (seconds)\nTLS session ticket:\n0000 - 02 45 a2 d3 29 fd 46 90-9e d1 42 c7 28 76 6c cb .E..).F\u2026B.(vl.\n0010 - 93 4d 50 f3 ac 62 67 38-5d 42 8c 90 0e 71 81 3c .MP..bg8]B\u2026q.<\n0020 - 55 13 3b 30 8f 98 3f 82-48 58 9b 95 08 91 8e 2d U.;0..?.HX\u2026..-\n0030 - 1d 47 2a 09 84 43 5b c3-ce e4 17 61 3b e6 f3 6c .G..C[\u2026.a;..l 0040 - 84 af c7 ab 50 0b 37 e6-4e a8 7b ef d2 11 54 3c \u2026.P.7.N.{\u2026T< 0050 - 27 95 0c 2e 29 4a 5c 9e-59 0c 0d fe 67 33 b1 a8 '\u2026)J.Y\u2026g3.. 0060 - 4a 8b 6e 3b e3 fe 81 b6-e2 46 8d d2 61 1d a7 eb J.n;\u2026..F..a\u2026 0070 - ff bb a6 ff 0f 6f 43 ac-28 85 d7 1b 4d ce 7a b8 \u2026..oC.(\u2026M.z. 0080 - 06 55 ab cd ad 6e 2a e0-8f a5 10 0a 91 84 61 0b .U\u2026n\u2026\u2026.a.\n0090 - 80 88 9a 13 fa 1e 4d 18-56 2e dd be f0 30 12 9a \u2026\u2026M.V\u2026.0..\n00a0 - 47 56 9a ad 90 02 4b 46-44 7c 73 81 e6 cc a3 26 GV\u2026.KFD|s\u2026.&\n00b0 - 6e 08 81 c5 3c 0a 33 cc-87 0b 4f 29 07 b2 b7 2a n\u2026<.3\u2026O)\u2026*\n00c0 - 52 75 1c 32 7b 0e 38 80-44 87 21 aa 15 5c 8a a3 Ru.2{.8.D.!....\n00d0 - d1 d3 ca 1f ef 2e 82 84-ba 80 02 73 4d 40 98 f5 \u2026\u2026\u2026..sM@..\n00e0 - a1 48 a0 62 4c 94 8f cc-8e da 4f 52 44 0d 50 36 .H.bL\u2026..ORD.P6\n00f0 - c0 93 88 80 51 \u2026.Q\n\nStart Time: 1736859994\nTimeout   : 7200 (sec)\nVerify return code: 0 (ok)\nExtended master secret: no\n\nMax Early Data: 14336\n\nread R BLOCK\n\nPost-Handshake New Session Ticket arrived:\nSSL-Session:\nProtocol : TLSv1.3\nCipher : TLS_AES_256_GCM_SHA384\nSession-ID: B2ACD78F3B5148DB3EB8886262F6B2835261A762E5188035F10F002711953E02\nSession-ID-ctx:\nResumption PSK: 4E8A3D784F9B4382ADF7B05C2ADE50DBF61E70DA6DE2E13CC9321D13C4A4AAE5C85655143E7988BCF0C748C8F9756CCD\nPSK identity: None\nPSK identity hint: None\nSRP username: None\nTLS session ticket lifetime hint: 172799 (seconds)\nTLS session ticket:\n0000 - 02 45 a2 d3 29 fd 46 90-9e d1 42 c7 28 76 6c cb .E..).F\u2026B.(vl.\n0010 - 64 85 26 2b 8c fe a5 02-af 47 10 41 70 c0 9a 80 d.&+\u2026..G.Ap\u2026\n0020 - ef 84 a6 37 98 bb d4 93-a5 dd 05 7a 1a 4f 18 14 \u20267\u2026\u2026.z.O..\n0030 - 19 92 db bb fc 0c cd d3-d7 d9 85 c4 07 ec 4c 0d \u2026\u2026\u2026\u2026..L.\n0040 - b1 74 6e 2e 21 7c 96 38-0c 87 06 59 71 d3 58 b7 .tn.!|.8\u2026Yq.X.\n0050 - c8 61 38 29 fb 89 44 60-2f 6a c7 ec a8 b7 fb 9a .a8)..D\/j...... 0060 - be 30 c7 12 05 2d f2 52-86 cc f9 be df d6 40 cb .0...-.R......@. 0070 - 74 1e 0c 95 ac ba c6 91-8a eb 45 71 01 10 0a 5a t.........Eq...Z 0080 - fa 44 f4 6e f9 9f 79 91-4a 05 2a 7a 89 80 d1 86 .D.n..y.J.*z.... 0090 - fd 2b 95 7d 7d e6 a4 e1-26 54 fd 81 08 3d 79 cd .+.}}...&T...=y. 00a0 - 29 b0 ed ff 64 8a 6f e5-cc 02 03 5a 66 23 b4 d5 )...d.o....Zf#.. 00b0 - 33 5f 5d 91 2a ad 1a 02-44 c7 cf 92 47 65 c1 9d 3_].*...D...Ge.. 00c0 - 05 aa 76 55 99 db 20 f6-69 48 1a aa 0e 69 34 8f ..vU.. .iH...i4. 00d0 - 17 25 9f 9a fa 1b de db-74 c2 4a 93 83 68 fe 0d .%......t.J..h.. 00e0 - 60 64 64 2f a2 28 bd 3f-ef ba 4f 52 44 34 75 57dd\/.(.?..ORD4uW\n00f0 - 0c 7a 3d 27 e9 .z='.\n\nStart Time: 1736859994\nTimeout   : 7200 (sec)\nVerify return code: 0 (ok)\nExtended master secret: no\n\nMax Early Data: 14336\n\nread R BLOCK\nHTTP\/1.0 400 Bad Request\nContent-Length: 54\nContent-Type: text\/h\ntml; charset=UTF-8\nDate: Tue, 14 Jan 2025 13:06:34 GMT\n\nAs you can notice there is detailed information about the SSL certificate, TLS <\/strong>version, ciphers<\/strong>, and even the SSL handshake<\/strong> between the client and the server.\nFrom the output we can see that, we connected successfully<\/code><\/pre>\n\n\n\n
CONNECTED(00000003)<\/code><\/pre>\n\n\n\n
You will find more details about the certificates, such as if the certificate is valid<\/p>\n\n\n\n
v:NotBefore: Dec 9 08:36:18 2024 GMT; NotAfter: Mar 3 08:36:17 2025 GMT<\/code><\/pre>\n\n\n\n
Then, which cipher does the server support or requires:<\/p>\n\n\n\n
New, TLSv1.3, Cipher is TLS_AES_256_GCM_SHA384<\/code><\/pre>\n\n\n\n
Also, you will find the SSL certificate.
Server certificate
—–BEGIN CERTIFICATE—–
MIIOCjCCDPKgAwIBAgIRANERcBmQhxEWCf0Wha+2dDQwDQYJKoZIhvcNAQELBQAw\u2026
…<\/p>\n\n\n\n
To check the SSL certificate chain, you can also use the command:<\/p>\n\n\n\n
openssl s_client -connect google.com:443 -showcerts<\/code><\/pre>\n\n\n\n
Specifying TLS version<\/h2>\n\n\n\n
Let\u2019s now try to connect by specifying the TLS version in the command. For this example, let\u2019s use TLS version 1.0.<\/p>\n\n\n\n
$ openssl s_client -tls1 -connect google.com:443<\/code><\/pre>\n\n\n\n
And you should receive a similar output:<\/p>\n\n\n\n
CONNECTED(00000003)\n\n40E79564507F0000:error:0A0000BF:SSL routines:tls_setup_handshake:no protocols available:..\/ssl\/statem\/statem_lib.c:104:\n\nno peer certificate available\n\nNo client certificate CA names sent\n\nSSL handshake has read 0 bytes and written 7 bytes\n\nVerification: OK\n\nNew, (NONE), Cipher is (NONE)\nSecure Renegotiation IS NOT supported\nCompression: NONE\nExpansion: NONE\nNo ALPN negotiated\nEarly data was not sent\nVerify return code: 0 (ok)\n\nYou can notice the lines\n\n40E79564507F0000:error:0A0000BF:SSL routines:tls_setup_handshake:no protocols available:..\/ssl\/statem\/statem_lib.c:104:\nSSL handshake has read 0 bytes and written 7 bytes\nThe TLS 1 protocol is not available and the SSL handshake was unsuccesfull, which is expected because the TLS version 1 and 1.1 are depricate. Now if you try to use TLS 1.2 or TLS 1.3 version the connection will be succesfull:\n\nopenssl s_client -tls1_3 -connect google.com:443 -brief\n\nCONNECTION ESTABLISHED\nProtocol version: TLSv1.3\nCiphersuite: TLS_AES_256_GCM_SHA384\nPeer certificate: CN = *.google.com\nHash used: SHA256\nSignature type: ECDSA\nVerification: OK\nServer Temp Key: X25519, 253 bits<\/code><\/pre>\n\n\n\n
You can also use the -brief<\/strong> flag for shorter output when using the OpenSSL s_client<\/strong> command.<\/p>\n\n\n\n
Unable to establish SSL connection.<\/h2>\n\n\n\n
If you are trying to connect to a URL that doesn\u2019t have an SSL certificate installed, you will receive this output:<\/p>\n\n\n\n
4097247D5C7F0000:error:8000006E:system library:BIO_connect:Connection timed out:..\/crypto\/bio\/bio_sock2.c:125:calling connect()\n4097247D5C7F0000:error:10000067:BIO routines:BIO_connect:connect error:..\/crypto\/bio\/bio_sock2.c:127:\nconnect:errno=110<\/code><\/pre>\n\n\n\n
Test IMAP, POP3, and SMTP connections with OpenSSL<\/h2>\n\n\n\n
You can also use the OpenSSL s_client<\/strong> to test the connections to the mail server for IMAP, POP3<\/strong>, and SMTP<\/strong>.
For SMTP<\/strong>, you should include the -starttls <\/strong>option, a command to inform the email server to upgrade from an insecure connection to a secure one. You will also include the -crlf<\/strong> option and specify the TLS version and SMTP port 587.<\/p>\n\n\n\n
$ openssl s_client -tls1_2 -crlf -connect outlook.office365.com:587 -starttls smtp -brief\n\nCONNECTION ESTABLISHED\nProtocol version: TLSv1.2\nCiphersuite: ECDHE-RSA-AES256-GCM-SHA384\nRequested Signature Algorithms: RSA-PSS+SHA256:RSA-PSS+SHA384:RSA-PSS+SHA512:RSA+SHA256:RSA+SHA384:RSA+SHA1:ECDSA+SHA256:ECDSA+SHA384:ECDSA+SHA1:DSA+SHA1:RSA+SHA512:ECDSA+SHA512\nPeer certificate: C = US, ST = Washington, L = Redmond, O = Microsoft Corporation, CN = outlook.com\nHash used: SHA256\nSignature type: RSA-PSS\nVerification: OK\nServer Temp Key: ECDH, secp384r1, 384 bits\n250 SMTPUTF8<\/code><\/pre>\n\n\n\n
For example, to check the POP3 connection with implicit port 995, you can use the command:<\/p>\n\n\n\n
$ openssl s_client -connect outlook.office365.com:993 -crlf -brief\n\nCONNECTION ESTABLISHED\nProtocol version: TLSv1.2\nCiphersuite: ECDHE-RSA-AES256-GCM-SHA384\nPeer certificate: C = US, ST = Washington, L = Redmond, O = Microsoft Corporation, CN = outlook.com\nHash used: SHA256\nSignature type: RSA-PSS\nVerification: OK\nServer Temp Key: ECDH, secp384r1, 384 bits\nOK The Microsoft Exchange IMAP4 service is ready. [QwBIADUAUAAyADIAMgBDAEEAMAAwADIAMwAuAE4AQQBNAFAAMgAyADIALgBQAFIATwBEAC4ATwBVAFQATABPAE8ASwAuAEMATwBNAA==]<\/code><\/pre>\n\n\n\n
Conclusion<\/h2>\n\n\n\n
OpenSSL’s s_client is a versatile tool for testing SSL\/TLS connectivity, verifying certificates, and debugging secure connections. It can help you diagnose your website SSL connection or your mail server, verify protocol support, or check for proper certificate configuration.<\/p>\n\n\n\n
If you have an active server management service<\/a> with us, you can log in to the client area and submit a ticket to request testing and troubleshooting SSL connections. Our experienced administrators are available 24\u00d77 and will take care of your request immediately.<\/p>\n\n\n\n
If you enjoyed this article and found it helpful, please comment or share this post with your friends.<\/p>
\"\"<\/a><\/div>\n","protected":false},"excerpt":{"rendered":"
OpenSSL is an open-source software library that provides cryptographic functions and tools for secure communication over computer networks. It supports implementing the Secure Sockets Layer (SSL) and Transport Layer Security (TLS) protocols, essential for encrypting data transmitted over the Internet and ensuring confidentiality, integrity, and authentication. OpenSSL comes preinstalled on almost all Linux distributions. In […]<\/p>\n","protected":false},"author":1,"featured_media":2283,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[226,307,308],"class_list":["post-2279","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-guides","tag-commands","tag-openssl","tag-s_client"],"yoast_head":"\nUsing OpenSSL s_client commands to test SSL connectivity | LinuxHostSupport<\/title>\n<meta name=\"description\" content=\"How can you use the OpenSSL s_client commands to test SSL connectivity? Learn everything you need in our latest guide.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/linuxhostsupport.com\/blog\/openssl-s_client-commands-to-test-ssl-connectivity\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Using OpenSSL s_client commands to test SSL connectivity | LinuxHostSupport\" \/>\n<meta property=\"og:description\" content=\"How can you use the OpenSSL s_client commands to test SSL connectivity? Learn everything you need in our latest guide.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/linuxhostsupport.com\/blog\/openssl-s_client-commands-to-test-ssl-connectivity\/\" \/>\n<meta property=\"og:site_name\" content=\"LinuxHostSupport\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/linuxhostsupport\" \/>\n<meta property=\"article:published_time\" content=\"2025-03-15T17:30:00+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/linuxhostsupport.com\/blog\/wp-content\/uploads\/2025\/01\/how-to-use-openssl-s-client-commands-to-test-ssl-connectivity.webp\" \/>\n\t<meta property=\"og:image:width\" content=\"742\" \/>\n\t<meta property=\"og:image:height\" content=\"410\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/webp\" \/>\n<meta name=\"author\" content=\"admin\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:creator\" content=\"@lnxhostsupport\" \/>\n<meta name=\"twitter:site\" content=\"@lnxhostsupport\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"admin\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"9 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/linuxhostsupport.com\\\/blog\\\/openssl-s_client-commands-to-test-ssl-connectivity\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/linuxhostsupport.com\\\/blog\\\/openssl-s_client-commands-to-test-ssl-connectivity\\\/\"},\"author\":{\"name\":\"admin\",\"@id\":\"https:\\\/\\\/linuxhostsupport.com\\\/blog\\\/#\\\/schema\\\/person\\\/53a9571ea078cdf350137a1e97423cfb\"},\"headline\":\"Using OpenSSL s_client commands to test SSL connectivity\",\"datePublished\":\"2025-03-15T17:30:00+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/linuxhostsupport.com\\\/blog\\\/openssl-s_client-commands-to-test-ssl-connectivity\\\/\"},\"wordCount\":484,\"commentCount\":0,\"image\":{\"@id\":\"https:\\\/\\\/linuxhostsupport.com\\\/blog\\\/openssl-s_client-commands-to-test-ssl-connectivity\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/linuxhostsupport.com\\\/blog\\\/wp-content\\\/uploads\\\/2025\\\/01\\\/how-to-use-openssl-s-client-commands-to-test-ssl-connectivity.webp\",\"keywords\":[\"commands\",\"openssl\",\"s_client\"],\"articleSection\":[\"Guides\"],\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\\\/\\\/linuxhostsupport.com\\\/blog\\\/openssl-s_client-commands-to-test-ssl-connectivity\\\/#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/linuxhostsupport.com\\\/blog\\\/openssl-s_client-commands-to-test-ssl-connectivity\\\/\",\"url\":\"https:\\\/\\\/linuxhostsupport.com\\\/blog\\\/openssl-s_client-commands-to-test-ssl-connectivity\\\/\",\"name\":\"Using OpenSSL s_client commands to test SSL connectivity | LinuxHostSupport\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/linuxhostsupport.com\\\/blog\\\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/linuxhostsupport.com\\\/blog\\\/openssl-s_client-commands-to-test-ssl-connectivity\\\/#primaryimage\"},\"image\":{\"@id\":\"https:\\\/\\\/linuxhostsupport.com\\\/blog\\\/openssl-s_client-commands-to-test-ssl-connectivity\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/linuxhostsupport.com\\\/blog\\\/wp-content\\\/uploads\\\/2025\\\/01\\\/how-to-use-openssl-s-client-commands-to-test-ssl-connectivity.webp\",\"datePublished\":\"2025-03-15T17:30:00+00:00\",\"author\":{\"@id\":\"https:\\\/\\\/linuxhostsupport.com\\\/blog\\\/#\\\/schema\\\/person\\\/53a9571ea078cdf350137a1e97423cfb\"},\"description\":\"How can you use the OpenSSL s_client commands to test SSL connectivity? Learn everything you need in our latest guide.\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/linuxhostsupport.com\\\/blog\\\/openssl-s_client-commands-to-test-ssl-connectivity\\\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/linuxhostsupport.com\\\/blog\\\/openssl-s_client-commands-to-test-ssl-connectivity\\\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/linuxhostsupport.com\\\/blog\\\/openssl-s_client-commands-to-test-ssl-connectivity\\\/#primaryimage\",\"url\":\"https:\\\/\\\/linuxhostsupport.com\\\/blog\\\/wp-content\\\/uploads\\\/2025\\\/01\\\/how-to-use-openssl-s-client-commands-to-test-ssl-connectivity.webp\",\"contentUrl\":\"https:\\\/\\\/linuxhostsupport.com\\\/blog\\\/wp-content\\\/uploads\\\/2025\\\/01\\\/how-to-use-openssl-s-client-commands-to-test-ssl-connectivity.webp\",\"width\":742,\"height\":410,\"caption\":\"How to Use OpenSSL s_client commands to test SSL connectivity\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/linuxhostsupport.com\\\/blog\\\/openssl-s_client-commands-to-test-ssl-connectivity\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/linuxhostsupport.com\\\/blog\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Using OpenSSL s_client commands to test SSL connectivity\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/linuxhostsupport.com\\\/blog\\\/#website\",\"url\":\"https:\\\/\\\/linuxhostsupport.com\\\/blog\\\/\",\"name\":\"LinuxHostSupport\",\"description\":\"Linux Tutorials and Guides\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/linuxhostsupport.com\\\/blog\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Person\",\"@id\":\"https:\\\/\\\/linuxhostsupport.com\\\/blog\\\/#\\\/schema\\\/person\\\/53a9571ea078cdf350137a1e97423cfb\",\"name\":\"admin\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/ed83c63a34114218f977e1f913be03906d17c7d9c800788fcac345f5edaf6cfa?s=96&d=mm&r=g\",\"url\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/ed83c63a34114218f977e1f913be03906d17c7d9c800788fcac345f5edaf6cfa?s=96&d=mm&r=g\",\"contentUrl\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/ed83c63a34114218f977e1f913be03906d17c7d9c800788fcac345f5edaf6cfa?s=96&d=mm&r=g\",\"caption\":\"admin\"},\"url\":\"https:\\\/\\\/linuxhostsupport.com\\\/blog\\\/author\\\/r0s3admin\\\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Using OpenSSL s_client commands to test SSL connectivity | LinuxHostSupport","description":"How can you use the OpenSSL s_client commands to test SSL connectivity? Learn everything you need in our latest guide.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/linuxhostsupport.com\/blog\/openssl-s_client-commands-to-test-ssl-connectivity\/","og_locale":"en_US","og_type":"article","og_title":"Using OpenSSL s_client commands to test SSL connectivity | LinuxHostSupport","og_description":"How can you use the OpenSSL s_client commands to test SSL connectivity? Learn everything you need in our latest guide.","og_url":"https:\/\/linuxhostsupport.com\/blog\/openssl-s_client-commands-to-test-ssl-connectivity\/","og_site_name":"LinuxHostSupport","article_publisher":"https:\/\/www.facebook.com\/linuxhostsupport","article_published_time":"2025-03-15T17:30:00+00:00","og_image":[{"width":742,"height":410,"url":"https:\/\/linuxhostsupport.com\/blog\/wp-content\/uploads\/2025\/01\/how-to-use-openssl-s-client-commands-to-test-ssl-connectivity.webp","type":"image\/webp"}],"author":"admin","twitter_card":"summary_large_image","twitter_creator":"@lnxhostsupport","twitter_site":"@lnxhostsupport","twitter_misc":{"Written by":"admin","Est. reading time":"9 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/linuxhostsupport.com\/blog\/openssl-s_client-commands-to-test-ssl-connectivity\/#article","isPartOf":{"@id":"https:\/\/linuxhostsupport.com\/blog\/openssl-s_client-commands-to-test-ssl-connectivity\/"},"author":{"name":"admin","@id":"https:\/\/linuxhostsupport.com\/blog\/#\/schema\/person\/53a9571ea078cdf350137a1e97423cfb"},"headline":"Using OpenSSL s_client commands to test SSL connectivity","datePublished":"2025-03-15T17:30:00+00:00","mainEntityOfPage":{"@id":"https:\/\/linuxhostsupport.com\/blog\/openssl-s_client-commands-to-test-ssl-connectivity\/"},"wordCount":484,"commentCount":0,"image":{"@id":"https:\/\/linuxhostsupport.com\/blog\/openssl-s_client-commands-to-test-ssl-connectivity\/#primaryimage"},"thumbnailUrl":"https:\/\/linuxhostsupport.com\/blog\/wp-content\/uploads\/2025\/01\/how-to-use-openssl-s-client-commands-to-test-ssl-connectivity.webp","keywords":["commands","openssl","s_client"],"articleSection":["Guides"],"inLanguage":"en-US","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/linuxhostsupport.com\/blog\/openssl-s_client-commands-to-test-ssl-connectivity\/#respond"]}]},{"@type":"WebPage","@id":"https:\/\/linuxhostsupport.com\/blog\/openssl-s_client-commands-to-test-ssl-connectivity\/","url":"https:\/\/linuxhostsupport.com\/blog\/openssl-s_client-commands-to-test-ssl-connectivity\/","name":"Using OpenSSL s_client commands to test SSL connectivity | LinuxHostSupport","isPartOf":{"@id":"https:\/\/linuxhostsupport.com\/blog\/#website"},"primaryImageOfPage":{"@id":"https:\/\/linuxhostsupport.com\/blog\/openssl-s_client-commands-to-test-ssl-connectivity\/#primaryimage"},"image":{"@id":"https:\/\/linuxhostsupport.com\/blog\/openssl-s_client-commands-to-test-ssl-connectivity\/#primaryimage"},"thumbnailUrl":"https:\/\/linuxhostsupport.com\/blog\/wp-content\/uploads\/2025\/01\/how-to-use-openssl-s-client-commands-to-test-ssl-connectivity.webp","datePublished":"2025-03-15T17:30:00+00:00","author":{"@id":"https:\/\/linuxhostsupport.com\/blog\/#\/schema\/person\/53a9571ea078cdf350137a1e97423cfb"},"description":"How can you use the OpenSSL s_client commands to test SSL connectivity? Learn everything you need in our latest guide.","breadcrumb":{"@id":"https:\/\/linuxhostsupport.com\/blog\/openssl-s_client-commands-to-test-ssl-connectivity\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/linuxhostsupport.com\/blog\/openssl-s_client-commands-to-test-ssl-connectivity\/"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/linuxhostsupport.com\/blog\/openssl-s_client-commands-to-test-ssl-connectivity\/#primaryimage","url":"https:\/\/linuxhostsupport.com\/blog\/wp-content\/uploads\/2025\/01\/how-to-use-openssl-s-client-commands-to-test-ssl-connectivity.webp","contentUrl":"https:\/\/linuxhostsupport.com\/blog\/wp-content\/uploads\/2025\/01\/how-to-use-openssl-s-client-commands-to-test-ssl-connectivity.webp","width":742,"height":410,"caption":"How to Use OpenSSL s_client commands to test SSL connectivity"},{"@type":"BreadcrumbList","@id":"https:\/\/linuxhostsupport.com\/blog\/openssl-s_client-commands-to-test-ssl-connectivity\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/linuxhostsupport.com\/blog\/"},{"@type":"ListItem","position":2,"name":"Using OpenSSL s_client commands to test SSL connectivity"}]},{"@type":"WebSite","@id":"https:\/\/linuxhostsupport.com\/blog\/#website","url":"https:\/\/linuxhostsupport.com\/blog\/","name":"LinuxHostSupport","description":"Linux Tutorials and Guides","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/linuxhostsupport.com\/blog\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Person","@id":"https:\/\/linuxhostsupport.com\/blog\/#\/schema\/person\/53a9571ea078cdf350137a1e97423cfb","name":"admin","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/secure.gravatar.com\/avatar\/ed83c63a34114218f977e1f913be03906d17c7d9c800788fcac345f5edaf6cfa?s=96&d=mm&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/ed83c63a34114218f977e1f913be03906d17c7d9c800788fcac345f5edaf6cfa?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/ed83c63a34114218f977e1f913be03906d17c7d9c800788fcac345f5edaf6cfa?s=96&d=mm&r=g","caption":"admin"},"url":"https:\/\/linuxhostsupport.com\/blog\/author\/r0s3admin\/"}]}},"_links":{"self":[{"href":"https:\/\/linuxhostsupport.com\/blog\/wp-json\/wp\/v2\/posts\/2279","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/linuxhostsupport.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/linuxhostsupport.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/linuxhostsupport.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/linuxhostsupport.com\/blog\/wp-json\/wp\/v2\/comments?post=2279"}],"version-history":[{"count":5,"href":"https:\/\/linuxhostsupport.com\/blog\/wp-json\/wp\/v2\/posts\/2279\/revisions"}],"predecessor-version":[{"id":2285,"href":"https:\/\/linuxhostsupport.com\/blog\/wp-json\/wp\/v2\/posts\/2279\/revisions\/2285"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/linuxhostsupport.com\/blog\/wp-json\/wp\/v2\/media\/2283"}],"wp:attachment":[{"href":"https:\/\/linuxhostsupport.com\/blog\/wp-json\/wp\/v2\/media?parent=2279"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/linuxhostsupport.com\/blog\/wp-json\/wp\/v2\/categories?post=2279"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/linuxhostsupport.com\/blog\/wp-json\/wp\/v2\/tags?post=2279"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}