Name : BETA-TESTERS
Project name : ZW3B-API-BETA-TESTERS
Authorized. - 200 - Client API Name and Origin Wildcard OK
Vérifier les suites de chiffrement d'un protocol de communication / #Openssl, #Ciphers, #SSL, #TLS, #StartTLS, #Postfix, #Apache
NdM : 2023/11/14 - Ébauche d'article.
Bonjour, aujourd'hui J'écris ce mémo sur quelques commandes concernant OpenSSL pour intéroger, pour vérifier les suites de chiffrement d'un protocol de communication.
Je vais utiliser OpenSSL, Nmap, Telnet et parler de Postfix le serveur MTA de mails.
Vérifier la suites des algorithmes de chiffrements autorisés sur un serveur.
Avec la commande de scann -> nmap <- et leur script ssl-enum-ciphers.
Script avec 33 lignes
001$ nmap --script ssl-enum-ciphers -p 443 www.zw3b.eu -6 002 003Starting Nmap 7.40 ( https://nmap.org ) at 2023-11-14 17:16 CET 004Nmap scan report for www.zw3b.eu (2607:5300:60:9389::1) 005Host is up (0.10s latency). 006Other addresses for www.zw3b.eu (not scanned): 158.69.126.137 007rDNS record for 2607:5300:60:9389::1: wan.ipv10.net 008PORT STATE SERVICE 009443/tcp open https 010| ssl-enum-ciphers: 011| TLSv1.2: 012| ciphers: 013| TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA (secp384r1) - A 014| TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 (secp384r1) - A 015| TLS_ECDHE_ECDSA_WITH_AES_128_CCM (secp384r1) - A 016| TLS_ECDHE_ECDSA_WITH_AES_128_CCM_8 (secp384r1) - A 017| TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 (secp384r1) - A 018| TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA (secp384r1) - A 019| TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 (secp384r1) - A 020| TLS_ECDHE_ECDSA_WITH_AES_256_CCM (secp384r1) - A 021| TLS_ECDHE_ECDSA_WITH_AES_256_CCM_8 (secp384r1) - A 022| TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 (secp384r1) - A 023| TLS_ECDHE_ECDSA_WITH_ARIA_128_GCM_SHA256 (secp384r1) - A 024| TLS_ECDHE_ECDSA_WITH_ARIA_256_GCM_SHA384 (secp384r1) - A 025| TLS_ECDHE_ECDSA_WITH_CAMELLIA_128_CBC_SHA256 (secp384r1) - A 026| TLS_ECDHE_ECDSA_WITH_CAMELLIA_256_CBC_SHA384 (secp384r1) - A 027| TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256 (secp384r1) - A 028| compressors: 029| NULL 030| cipher preference: client 031|_ least strength: A 032 033Nmap done: 1 IP address (1 host up) scanned in 9.54 seconds
Je peut utiliser la commande -> openssl s_client
Je peut essayer de me conecter au site s'il dispose d'un certificat tls1_3, tls1_2, tls1_1
Script avec 57 lignes
001echo | openssl s_client -showcerts -connect www.zw3b.eu:443 -servername www.zw3b.eu -tls1_3 002CONNECTED(00000003) 003depth=2 C = US, O = Internet Security Research Group, CN = ISRG Root X1 004verify return:1 005depth=1 C = US, O = Let's Encrypt, CN = R3 006verify return:1 007depth=0 CN = zw3b.eu 008verify return:1 009--- 010Certificate chain 011 0 s:CN = zw3b.eu 012 i:C = US, O = Let's Encrypt, CN = R3 013-----BEGIN CERTIFICATE----- 014MIIEOTCCAyGgAwIBAgISBLozcwPm7Dwnu132Z9sR/uHyMA0GCSqGSIb3DQEBCwUA 015[...] 016s41KxazyA1yD0dnXPE9u9m5i3Uu8nZrGOuHcJxM= 017-----END CERTIFICATE----- 018 1 s:C = US, O = Let's Encrypt, CN = R3 019 i:C = US, O = Internet Security Research Group, CN = ISRG Root X1 020-----BEGIN CERTIFICATE----- 021MIIFFjCCAv6gAwIBAgIRAJErCErPDBinU/bWLiWnX1owDQYJKoZIhvcNAQELBQAw 022[...] 023MldlTTKB3zhThV1+XWYp6rjd5JW1zbVWEkLNxE7GJThEUG3szgBVGP7pSWTUTsqX 024nLRbwHOoq7hHwg== 025-----END CERTIFICATE----- 026 2 s:C = US, O = Internet Security Research Group, CN = ISRG Root X1 027 i:O = Digital Signature Trust Co., CN = DST Root CA X3 028-----BEGIN CERTIFICATE----- 029MIIFYDCCBEigAwIBAgIQQAF3ITfU6UK47naqPGQKtzANBgkqhkiG9w0BAQsFADA/ 030[...] 031Dfvp7OOGAN6dEOM4+qR9sdjoSYKEBpsr6GtPAQw4dy753ec5 032-----END CERTIFICATE----- 033--- 034Server certificate 035subject=CN = zw3b.eu 036 037issuer=C = US, O = Let's Encrypt, CN = R3 038 039--- 040No client certificate CA names sent 041Peer signing digest: SHA384 042Peer signature type: ECDSA 043Server Temp Key: X25519, 253 bits 044--- 045SSL handshake has read 4188 bytes and written 315 bytes 046Verification: OK 047--- 048New, TLSv1.3, Cipher is TLS_AES_256_GCM_SHA384 049Server public key is 384 bit 050Secure Renegotiation IS NOT supported 051Compression: NONE 052Expansion: NONE 053No ALPN negotiated 054Early data was not sent 055Verify return code: 0 (ok) 056--- 057DONE
Voir le certificat d'un site avec en plus openssl x509 et les options -text -noout (pour un certificat local utiliser l'option -in file.pem).
Script avec 94 lignes
001$ echo | openssl s_client -showcerts -connect www.zw3b.eu:443 -servername www.zw3b.eu -tls1_3 | openssl x509 -text -noout 002depth=2 C = US, O = Internet Security Research Group, CN = ISRG Root X1 003verify return:1 004depth=1 C = US, O = Let's Encrypt, CN = R3 005verify return:1 006depth=0 CN = zw3b.eu 007verify return:1 008Certificate: 009 Data: 010 Version: 3 (0x2) 011 Serial Number: 012 04:ba:33:73:03:e6:ec:3c:27:bb:5d:f6:67:db:11:fe:e1:f2 013 Signature Algorithm: sha256WithRSAEncryption 014 Issuer: C = US, O = Let's Encrypt, CN = R3 015 Validity 016 Not Before: Sep 24 21:39:12 2023 GMT 017 Not After : Dec 23 21:39:11 2023 GMT 018 Subject: CN = zw3b.eu 019 Subject Public Key Info: 020 Public Key Algorithm: id-ecPublicKey 021 Public-Key: (384 bit) 022 pub: 023 04:c3:77:94:e0:af:ca:10:c4:c4:0e:ab:e4:16:14: 024 6a:79:00:3e:d2:20:a3:8a:f4:e2:13:06:3b:ce:67: 025 38:93:ff:57:69:77:7f:d5:5d:dd:d5:6e:c2:f3:b4: 026 bb:59:7b:5d:f3:00:92:c8:c4:2d:91:15:aa:70:14: 027 22:7d:f3:cc:d5:0a:04:85:33:48:88:f7:ab:cf:3c: 028 f2:73:6c:34:3f:50:e0:78:e1:88:56:83:f9:cc:fa: 029 9d:89:c9:8b:58:bc:e9 030 ASN1 OID: secp384r1 031 NIST CURVE: P-384 032 X509v3 extensions: 033 X509v3 Key Usage: critical 034 Digital Signature 035 X509v3 Extended Key Usage: 036 TLS Web Server Authentication, TLS Web Client Authentication 037 X509v3 Basic Constraints: critical 038 CA:FALSE 039 X509v3 Subject Key Identifier: 040 18:7A:A8:66:84:77:A4:B8:BD:44:19:09:B2:9C:74:06:48:5D:AB:36 041 X509v3 Authority Key Identifier: 042 keyid:14:2E:B3:17:B7:58:56:CB:AE:50:09:40:E6:1F:AF:9D:8B:14:C2:C6 043 044 Authority Information Access: 045 OCSP - URI:http://r3.o.lencr.org 046 CA Issuers - URI:http://r3.i.lencr.org/ 047 048 X509v3 Subject Alternative Name: 049 DNS:*.zw3b.eu, DNS:zw3b.eu 050 X509v3 Certificate Policies: 051 Policy: 2.23.140.1.2.1 052 053 CT Precertificate SCTs: 054 Signed Certificate Timestamp: 055 Version : v1 (0x0) 056 Log ID : B7:3E:FB:24:DF:9C:4D:BA:75:F2:39:C5:BA:58:F4:6C: 057 5D:FC:42:CF:7A:9F:35:C4:9E:1D:09:81:25:ED:B4:99 058 Timestamp : Sep 24 22:39:13.014 2023 GMT 059 Extensions: none 060 Signature : ecdsa-with-SHA256 061 30:45:02:21:00:D1:84:23:8C:C2:68:20:52:97:2E:FA: 062 1A:B5:88:A4:F8:1A:46:78:38:17:24:63:90:C8:BB:13: 063 30:DD:99:1B:E5:02:20:29:19:0B:8E:A0:8D:61:BE:5C: 064 F4:34:97:BF:98:94:13:43:17:86:B5:3B:75:10:75:62: 065 CD:1A:3D:0D:E0:3D:D3 066 Signed Certificate Timestamp: 067 Version : v1 (0x0) 068 Log ID : 7A:32:8C:54:D8:B7:2D:B6:20:EA:38:E0:52:1E:E9:84: 069 16:70:32:13:85:4D:3B:D2:2B:C1:3A:57:A3:52:EB:52 070 Timestamp : Sep 24 22:39:13.078 2023 GMT 071 Extensions: none 072 Signature : ecdsa-with-SHA256 073 30:46:02:21:00:C4:19:58:41:52:FF:84:DD:4C:C2:10: 074 94:EF:01:F6:FE:A3:5F:BB:97:91:55:F7:BF:94:3F:8C: 075 A0:AD:C6:A7:28:02:21:00:C5:03:34:4B:3E:2A:C8:27: 076 F0:B6:E6:C2:DF:5D:13:26:D1:01:D8:CA:70:8C:8C:77: 077 74:68:87:79:FC:67:DB:BD 078 Signature Algorithm: sha256WithRSAEncryption 079 09:fa:05:97:8f:9f:87:5e:06:0e:26:25:94:ca:c4:1e:51:13: 080 e7:14:e1:6d:74:b0:24:05:b9:60:4d:75:48:b4:49:8f:92:14: 081 aa:b6:2d:ac:43:fd:5e:07:1a:20:b7:7a:53:f6:23:16:68:34: 082 6e:9f:79:cb:bc:52:bb:74:a0:a0:20:ff:ab:ba:f7:67:aa:8f: 083 2d:fc:e3:55:92:f3:c6:dd:f3:f3:31:22:0f:ce:03:b6:82:d1: 084 72:0b:50:de:1b:9f:e2:6e:56:fa:22:c6:ee:b6:d0:1a:da:fd: 085 db:bd:be:92:69:3d:59:fa:2c:04:0d:09:dc:60:c0:75:d8:7d: 086 2c:79:71:e3:1a:3a:77:40:de:8f:60:40:69:d6:1f:1d:2b:08: 087 67:90:7a:ea:1e:9c:13:20:d4:ca:8b:0e:06:23:18:11:92:64: 088 67:46:aa:45:12:08:4d:a3:43:2b:85:6f:8a:11:2c:38:67:ca: 089 62:7d:6b:e9:1e:28:b2:83:0c:cd:e2:1f:71:97:df:f6:6b:b7: 090 ed:77:81:48:2d:94:0f:ae:d5:62:d4:3c:f7:e0:52:a1:60:55: 091 3e:f7:8c:cf:b1:35:96:af:ff:60:66:b3:8d:4a:c5:ac:f2:03: 092 5c:83:d1:d9:d7:3c:4f:6e:f6:6e:62:dd:4b:bc:9d:9a:c6:3a: 093 e1:dc:27:13 094DONE
Note : Voir un certificat local openssl x509 -text -noout -in file.pem.
On peut visualiser d'autres protocoles que le HTTPS (port 443).
Après cette introduction, je vais vous parler des procotoles SMTPs IMAPs POPs...
Par exemple le service STMP (port 25) ou SMTPs (port 465) ou SMTPS with StartTLS (port 587)
Ci-dessous, j'envoie un commande sur le port 25 (SMTP) sans sécurité avec en option "starttls" pour activer la transmission sécurisée.
Script avec 67 lignes
001$ echo | openssl s_client -starttls smtp -showcerts -connect smtp.zw3b.eu:25 -servername smtp.zw3b.eu 002CONNECTED(00000003) 003depth=2 C = US, O = Internet Security Research Group, CN = ISRG Root X1 004verify return:1 005depth=1 C = US, O = Let's Encrypt, CN = R3 006verify return:1 007depth=0 CN = mail.zw3b.eu 008verify return:1 009--- 010Certificate chain 011 0 s:CN = mail.zw3b.eu 012 i:C = US, O = Let's Encrypt, CN = R3 013-----BEGIN CERTIFICATE----- 014MIIGRjCCBS6gAwIBAgISBAO2RR2xXxEujKzQr5wV6Wf+MA0GCSqGSIb3DQEBCwUA 015[...] 016GpjuiyV0VMVKFUUPfTKf2BDeQkQlPWUdnZj1W7ROCES6TB4CUv/IVbr1DI6M1Erj 0172qAdtLT7EypMLxFAXAKB5uwr0mYf0mihwQs= 018-----END CERTIFICATE----- 019 1 s:CN = mail.zw3b.eu 020 i:C = US, O = Let's Encrypt, CN = R3 021-----BEGIN CERTIFICATE----- 022MIIGRjCCBS6gAwIBAgISBAO2RR2xXxEujKzQr5wV6Wf+MA0GCSqGSIb3DQEBCwUA 023[...] 024GpjuiyV0VMVKFUUPfTKf2BDeQkQlPWUdnZj1W7ROCES6TB4CUv/IVbr1DI6M1Erj 0252qAdtLT7EypMLxFAXAKB5uwr0mYf0mihwQs= 026-----END CERTIFICATE----- 027 2 s:C = US, O = Let's Encrypt, CN = R3 028 i:C = US, O = Internet Security Research Group, CN = ISRG Root X1 029-----BEGIN CERTIFICATE----- 030MIIFFjCCAv6gAwIBAgIRAJErCErPDBinU/bWLiWnX1owDQYJKoZIhvcNAQELBQAw 031[...] 032MldlTTKB3zhThV1+XWYp6rjd5JW1zbVWEkLNxE7GJThEUG3szgBVGP7pSWTUTsqX 033nLRbwHOoq7hHwg== 034-----END CERTIFICATE----- 035 3 s:C = US, O = Internet Security Research Group, CN = ISRG Root X1 036 i:C = US, O = Internet Security Research Group, CN = ISRG Root X1 037-----BEGIN CERTIFICATE----- 038MIIFazCCA1OgAwIBAgIRAIIQz7DSQONZRGPgu2OCiwAwDQYJKoZIhvcNAQELBQAw 039[...] 040emyPxgcYxn/eR44/KJ4EBs+lVDR3veyJm+kXQ99b21/+jh5Xos1AnX5iItreGCc= 041-----END CERTIFICATE----- 042--- 043Server certificate 044subject=CN = mail.zw3b.eu 045 046issuer=C = US, O = Let's Encrypt, CN = R3 047 048--- 049No client certificate CA names sent 050Peer signing digest: SHA384 051Peer signature type: ECDSA 052Server Temp Key: X25519, 253 bits 053--- 054SSL handshake has read 6536 bytes and written 417 bytes 055Verification: OK 056--- 057New, TLSv1.3, Cipher is TLS_AES_256_GCM_SHA384 058Server public key is 384 bit 059Secure Renegotiation IS NOT supported 060Compression: NONE 061Expansion: NONE 062No ALPN negotiated 063Early data was not sent 064Verify return code: 0 (ok) 065--- 066250 CHUNKING 067DONE
Ci-dessous, j'envoie une commande sur le port 465 (SMTPs) donc sécurisée.
Script avec 67 lignes
001echo | openssl s_client -showcerts -connect smtp.zw3b.eu:465 -servername smtp.zw3b.eu 002CONNECTED(00000003) 003depth=2 C = US, O = Internet Security Research Group, CN = ISRG Root X1 004verify return:1 005depth=1 C = US, O = Let's Encrypt, CN = R3 006verify return:1 007depth=0 CN = mail.zw3b.eu 008verify return:1 009--- 010Certificate chain 011 0 s:CN = mail.zw3b.eu 012 i:C = US, O = Let's Encrypt, CN = R3 013-----BEGIN CERTIFICATE----- 014MIIGRjCCBS6gAwIBAgISBAO2RR2xXxEujKzQr5wV6Wf+MA0GCSqGSIb3DQEBCwUA 015[...] 016GpjuiyV0VMVKFUUPfTKf2BDeQkQlPWUdnZj1W7ROCES6TB4CUv/IVbr1DI6M1Erj 0172qAdtLT7EypMLxFAXAKB5uwr0mYf0mihwQs= 018-----END CERTIFICATE----- 019 1 s:CN = mail.zw3b.eu 020 i:C = US, O = Let's Encrypt, CN = R3 021-----BEGIN CERTIFICATE----- 022MIIGRjCCBS6gAwIBAgISBAO2RR2xXxEujKzQr5wV6Wf+MA0GCSqGSIb3DQEBCwUA 023[...] 024GpjuiyV0VMVKFUUPfTKf2BDeQkQlPWUdnZj1W7ROCES6TB4CUv/IVbr1DI6M1Erj 0252qAdtLT7EypMLxFAXAKB5uwr0mYf0mihwQs= 026-----END CERTIFICATE----- 027 2 s:C = US, O = Let's Encrypt, CN = R3 028 i:C = US, O = Internet Security Research Group, CN = ISRG Root X1 029-----BEGIN CERTIFICATE----- 030MIIFFjCCAv6gAwIBAgIRAJErCErPDBinU/bWLiWnX1owDQYJKoZIhvcNAQELBQAw 031[...] 032MldlTTKB3zhThV1+XWYp6rjd5JW1zbVWEkLNxE7GJThEUG3szgBVGP7pSWTUTsqX 033nLRbwHOoq7hHwg== 034-----END CERTIFICATE----- 035 3 s:C = US, O = Internet Security Research Group, CN = ISRG Root X1 036 i:C = US, O = Internet Security Research Group, CN = ISRG Root X1 037-----BEGIN CERTIFICATE----- 038MIIFazCCA1OgAwIBAgIRAIIQz7DSQONZRGPgu2OCiwAwDQYJKoZIhvcNAQELBQAw 039TzELMAkGA1UEBhMCVVMxKTAnBgNVBAoTIEludGVybmV0IFNlY3VyaXR5IFJlc2Vh 040[...] 041emyPxgcYxn/eR44/KJ4EBs+lVDR3veyJm+kXQ99b21/+jh5Xos1AnX5iItreGCc= 042-----END CERTIFICATE----- 043--- 044Server certificate 045subject=CN = mail.zw3b.eu 046 047issuer=C = US, O = Let's Encrypt, CN = R3 048 049--- 050No client certificate CA names sent 051Peer signing digest: SHA384 052Peer signature type: ECDSA 053Server Temp Key: X25519, 253 bits 054--- 055SSL handshake has read 6336 bytes and written 384 bytes 056Verification: OK 057--- 058New, TLSv1.3, Cipher is TLS_AES_256_GCM_SHA384 059Server public key is 384 bit 060Secure Renegotiation IS NOT supported 061Compression: NONE 062Expansion: NONE 063No ALPN negotiated 064Early data was not sent 065Verify return code: 0 (ok) 066--- 067DONE
Ci-dessous, j'envoie une commande sur le port 587 (SMTPs) (dans un serveur MAIL comme Postfix, la demande StartTLS est automatique). Ici, c'est "openssl" le client, il faut lui envoyer l'opion nous même, tout comme nous l'avons fait en se connectant sur le port 25.
Script avec 67 lignes
001$ echo | openssl s_client -starttls smtp -showcerts -connect smtp.zw3b.eu:587 -servername smtp.zw3b.eu 002CONNECTED(00000003) 003depth=2 C = US, O = Internet Security Research Group, CN = ISRG Root X1 004verify return:1 005depth=1 C = US, O = Let's Encrypt, CN = R3 006verify return:1 007depth=0 CN = mail.zw3b.eu 008verify return:1 009--- 010Certificate chain 011 0 s:CN = mail.zw3b.eu 012 i:C = US, O = Let's Encrypt, CN = R3 013-----BEGIN CERTIFICATE----- 014MIIGRjCCBS6gAwIBAgISBAO2RR2xXxEujKzQr5wV6Wf+MA0GCSqGSIb3DQEBCwUA 015[...] 016GpjuiyV0VMVKFUUPfTKf2BDeQkQlPWUdnZj1W7ROCES6TB4CUv/IVbr1DI6M1Erj 0172qAdtLT7EypMLxFAXAKB5uwr0mYf0mihwQs= 018-----END CERTIFICATE----- 019 1 s:CN = mail.zw3b.eu 020 i:C = US, O = Let's Encrypt, CN = R3 021-----BEGIN CERTIFICATE----- 022MIIGRjCCBS6gAwIBAgISBAO2RR2xXxEujKzQr5wV6Wf+MA0GCSqGSIb3DQEBCwUA 023[...] 024GpjuiyV0VMVKFUUPfTKf2BDeQkQlPWUdnZj1W7ROCES6TB4CUv/IVbr1DI6M1Erj 0252qAdtLT7EypMLxFAXAKB5uwr0mYf0mihwQs= 026-----END CERTIFICATE----- 027 2 s:C = US, O = Let's Encrypt, CN = R3 028 i:C = US, O = Internet Security Research Group, CN = ISRG Root X1 029-----BEGIN CERTIFICATE----- 030MIIFFjCCAv6gAwIBAgIRAJErCErPDBinU/bWLiWnX1owDQYJKoZIhvcNAQELBQAw 031[...] 032MldlTTKB3zhThV1+XWYp6rjd5JW1zbVWEkLNxE7GJThEUG3szgBVGP7pSWTUTsqX 033nLRbwHOoq7hHwg== 034-----END CERTIFICATE----- 035 3 s:C = US, O = Internet Security Research Group, CN = ISRG Root X1 036 i:C = US, O = Internet Security Research Group, CN = ISRG Root X1 037-----BEGIN CERTIFICATE----- 038MIIFazCCA1OgAwIBAgIRAIIQz7DSQONZRGPgu2OCiwAwDQYJKoZIhvcNAQELBQAw 039[...] 040emyPxgcYxn/eR44/KJ4EBs+lVDR3veyJm+kXQ99b21/+jh5Xos1AnX5iItreGCc= 041-----END CERTIFICATE----- 042--- 043Server certificate 044subject=CN = mail.zw3b.eu 045 046issuer=C = US, O = Let's Encrypt, CN = R3 047 048--- 049No client certificate CA names sent 050Peer signing digest: SHA384 051Peer signature type: ECDSA 052Server Temp Key: X25519, 253 bits 053--- 054SSL handshake has read 6537 bytes and written 417 bytes 055Verification: OK 056--- 057New, TLSv1.3, Cipher is TLS_AES_256_GCM_SHA384 058Server public key is 384 bit 059Secure Renegotiation IS NOT supported 060Compression: NONE 061Expansion: NONE 062No ALPN negotiated 063Early data was not sent 064Verify return code: 0 (ok) 065--- 066250 CHUNKING 067DONE
On peut utiliser telnet pour se connecter au serveur SMTP :
Script avec 5 lignes
001$ telnet mail.zw3b.eu 25 002Trying 2607:5300:60:9389:17:4c1:0:1a... 003Connected to mail.zw3b.eu. 004Escape character is '^]'. 005220 mail.zw3b.eu ESMTP Postfix
Il faut envoyer un "nom de domaine" avec la commande SMTP :
Script avec 1 ligne
001EHLO zw3b.eu
Qui nous connecte au serveur et retourne ces informations en attente d'une authentification :
Script avec 9 lignes
001250-mail.zw3b.eu 002250-PIPELINING 003250-SIZE 20480000 004250-ETRN 005250-STARTTLS 006250-ENHANCEDSTATUSCODES 007250-8BITMIME 008250-DSN 009250 CHUNKING
On peut s'identifier sur le serveur comme expliquer sur cette page -> test-smtp-with-telnet-or-openssl .
...