Postfix and OpenJDK 11: "No appropriate protocol (protocol is disabled or cipher suites are inappropriate)" – CentOS

I know there are some other questions (with answers) to this topic. But none of these was helpful for me.

I have a Postfix server (postfix 3.4.14 on Debian 10 (Buster)) with the following configuration (only the interesting section):

smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3, !TLSv1, !TLSv1.1
smtp_tls_mandatory_protocols = !SSLv2, !SSLv3, !TLSv1, !TLSv1.1
smtp_tls_protocols = !SSLv2, !SSLv3, !TLSv1, !TLSv1.1
smtpd_tls_protocols = !SSLv2, !SSLv3, !TLSv1, !TLSv1.1
smtpd_tls_exclude_ciphers = aNULL, LOW, EXP, MEDIUM, ADH, AECDH, MD5, DSS, ECDSA,
    CAMELLIA128, 3DES, CAMELLIA256, RSA+AES, eNULL
smtp_tls_exclude_ciphers = aNULL, LOW, EXP, MEDIUM, ADH, AECDH, MD5, DSS, ECDSA,
    CAMELLIA128, 3DES, CAMELLIA256, RSA+AES, eNULL
tls_preempt_cipherlist = yes
tls_high_cipherlist = !aNULL:!eNULL:!CAMELLIA:HIGH:@STRENGTH

If I check the configuration with OpenSSL, I get (please note that I have made the domain name unrecognizable with "xxxxxx.de"):

#> openssl s_client -connect xxxxxx.de:25 -starttls smtp
CONNECTED(00000003)
depth=3 O = Digital Signature Trust Co., CN = DST Root CA X3
verify return:1
depth=2 C = US, O = Internet Security Research Group, CN = ISRG Root X1
verify return:1
depth=1 C = US, O = Let's Encrypt, CN = R3
verify return:1
depth=0 CN = xxxxxx.de
verify return:1
---
Certificate chain
 0 s:/CN=xxxxxx.de
   i:/C=US/O=Let's Encrypt/CN=R3
 1 s:/C=US/O=Let's Encrypt/CN=R3
   i:/C=US/O=Internet Security Research Group/CN=ISRG Root X1
 2 s:/C=US/O=Internet Security Research Group/CN=ISRG Root X1
   i:/O=Digital Signature Trust Co./CN=DST Root CA X3
---
Server certificate
-----BEGIN CERTIFICATE-----
MIIFRjCCBC6gAwIBAgISA6SNmc1MPKtxwSiNNKEvxc/EMA0GCSqGSIb3DQEBCwUA
MDIxCzAJBgNVBAYTAlVTMRYwFAYDVQQKEw1MZXQncyBFbmNyeXB0MQswCQYDVQQD
...
...
...
VG2iG8sEGCcgG4w1LnWTO4tMlCYFE+tcXxAfE/7pB/VjmvRZlLCypanuwBzVRw5W
bPwabUtCMRDrRlT8wI9UHAhQYTb5Hhm0F0u1hi6e/7fybK6tuFnPpWs/vgT3Z4Fj
2onoaTHk/rKlhQ==
-----END CERTIFICATE-----
subject=/CN=xxxxxx.de
issuer=/C=US/O=Let's Encrypt/CN=R3
---
No client certificate CA names sent
Peer signing digest: SHA256
Server Temp Key: ECDH, P-256, 256 bits
---
SSL handshake has read 4950 bytes and written 450 bytes
---
New, TLSv1/SSLv3, Cipher is ECDHE-RSA-AES256-GCM-SHA384
Server public key is 2048 bit
Secure Renegotiation IS supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
SSL-Session:
    Protocol  : TLSv1.2
    Cipher    : ECDHE-RSA-AES256-GCM-SHA384
    Session-ID: B20E725616C98083988847B90FB42BFDCAEED745129C53E79E723692C641F6F5
    Session-ID-ctx:
    Master-Key: A3D2C497E11E47C6260C119E47DC3B4CAA119485EAFA5BCF6CDA882F115D80E78960C802A48E375DAA293A3A2C1DAE35
    Key-Arg   : None
    Krb5 Principal: None
    PSK identity: None
    PSK identity hint: None
    TLS session ticket lifetime hint: 7200 (seconds)
    TLS session ticket:
    0000 - ec 40 39 d6 f4 94 ac 7b-d8 f8 ef 94 98 62 d7 35   .@9....{.....b.5
    0010 - de fb c3 f5 f3 b1 3a d1-24 3e 62 57 fb 06 56 eb   ......:.$>bW..V.
    0020 - 84 61 2a 0d 30 7d 9f ac-70 e7 a8 a3 23 4a c6 57   .a*.0}..p...#J.W
    0030 - dc 21 7c d3 5d f4 e8 14-c5 4c 18 da 35 1d 32 49   .!|.]....L..5.2I
    0040 - f0 19 de 75 77 22 25 f9-74 4d a2 47 39 0d ce 75   ...uw"%.tM.G9..u
    0050 - 0a 04 41 85 0d 67 05 fe-a4 09 ec 72 4b a5 ad f4   ..A..g.....rK...
    0060 - 8b 73 a2 a3 2e 28 46 b8-2a 60 4b ed ce 75 09 fb   .s...(F.*`K..u..
    0070 - ef 95 e3 e2 6e 6a 90 bd-9e 46 e8 c9 aa 52 c3 ae   ....nj...F...R..
    0080 - 72 6f 9f 37 fd 6c 12 e9-bb 60 83 c6 c4 44 ca 85   ro.7.l...`...D..
    0090 - cb ee 1d bd 69 29 77 31-4f 96 d5 4d 93 8e 63 d2   ....i)w1O..M..c.

    Start Time: 1623221077
    Timeout   : 300 (sec)
    Verify return code: 0 (ok)
---
250 CHUNKING

Here I’m wondering about the line

New, TLSv1/SSLv3, Cipher is ECDHE-RSA-AES256-GCM-SHA384

because TLSv1/SSLv3 should be disabled by the postfix configuration. Could be that the problem?

However. On the client side I have a Java application (OpenJDK 11.0.11) and every time I will send an email I get:

javax.mail.MessagingException: Could not convert socket to TLS;
nested exception is:
javax.net.ssl.SSLHandshakeException: No appropriate protocol (protocol is disabled or cipher suites are inappropriate)
at com.sun.mail.smtp.SMTPTransport.startTLS(SMTPTransport.java:1907)
at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:666)
at javax.mail.Service.connect(Service.java:295)
...

Of course, I have already edited the conf/security/java.security file. I have added already ECDHE-RSA-AES256-GCM-SHA384 as jdk.tls.legacyAlgorithms. Here are the interesting settings from java.securtity:

jdk.tls.legacyAlgorithms= 
        K_NULL, C_NULL, M_NULL, 
        DH_anon, ECDH_anon, 
        RC4_128, RC4_40, DES_CBC, DES40_CBC, 
        3DES_EDE_CBC, ECDHE-RSA-AES256-GCM, ECDHE-RSA-AES256-GCM-SHA384

jdk.certpath.disabledAlgorithms=MD2, MD5, SHA1 jdkCA & usage TLSServer, 
    RSA keySize < 1024, DSA keySize < 1024, EC keySize < 224, 
    include jdk.disabled.namedCurves

jdk.tls.disabledAlgorithms=SSLv3, TLSv1, TLSv1.1, RC4, DES, MD5withRSA, 
    DH keySize < 1024, EC keySize < 224, 3DES_EDE_CBC, anon, NULL, 
    include jdk.disabled.namedCurves

May be I’m blind, but I don’t see where my problem is …

Ok, at first I have removed my extensions from jdk.tls.legacyAlgorithms, because these are not helpful and wrong (thanks to dave_thompson_085 for the hint).

Here are the Java code for sending the emails (the code has a "long" history, so please don’t wonder why there are Vector instead of ArrayList or so was used…)

// Create some properties and get the default Session
Properties props = new Properties();
props.put("mail.smtp.host", smtpServer);
props.put("mail.smtp.port", "25");
props.put("mail.debug", "true");

// SMTP authentication?
Session session;
if (username != null && pwd != null && username.length() > 0 && pwd.length() > 0) {
  props.put("mail.smtp.auth", "true");
  //props.put("mail.smtp.user", username);
  //props.put("mail.password", pwd);

  // if SMTP authentication: use TLS in every case!
  tls = true;

  session = Session.getInstance(props, new MyPasswordAuthenticator(username, pwd));
} else {
  session = Session.getDefaultInstance(props, null);
}

// TLS?
if (tls) {
  props.put("mail.smtp.starttls.enable", "true");
  //props.put("mail.smtp.tls", "true");
}

// create a message
SMTPMessage mimeMsg = new SMTPMessage(session);

InternetAddress addressFrom = new InternetAddress(sender);
mimeMsg.setFrom(addressFrom);
mimeMsg.setEnvelopeFrom(sender);

// Set recipients ...
InternetAddress[] tos = new InternetAddress[receivers.size()];
int i = 0;
for (String addr : receivers) {
  tos[i++] = new InternetAddress(addr, extractPersonalNameFromEMailAddr(addr));
}

// Set CC recipients ...
InternetAddress[] ccAddrs = new InternetAddress[0];
if (ccs != null) {
  ccAddrs = new InternetAddress[ccs.size()];

  i = 0;
  for (String addr : ccs) {
    ccAddrs[i++] = new InternetAddress(addr, extractPersonalNameFromEMailAddr(addr));
  }
}

mimeMsg.setRecipients(Message.RecipientType.TO, tos);
mimeMsg.setRecipients(Message.RecipientType.CC, ccAddrs);

// Set return notifications
if (readNotificationRequest) {
  String notifyAddr = replyTo;
  if (notifyAddr == null || notifyAddr.trim().length() == 0) notifyAddr = sender;

  mimeMsg.addHeader("Disposition-Notification-To", "<" + notifyAddr + ">");
  mimeMsg.addHeader("Return-Receipt-To", "<" + notifyAddr + ">");
}

mimeMsg.addHeader("Date", mailDateFormat.format(new Date()));

mimeMsg.setNotifyOptions(deliverNotificationRequest);
mimeMsg.setReturnOption(deliverNotificationContent);

if (replyTo != null) {
  Address[] replyToAddrs = new Address[1];
  replyToAddrs[0] = new InternetAddress(this.replyTo);

  mimeMsg.setReplyTo(replyToAddrs);
  mimeMsg.setFrom(replyToAddrs[0]);
}

mimeMsg.setSentDate(new Date());
mimeMsg.setSubject(subject);
//mimeMsg.setContent(msg, msgType);

// Set the text content:
MimeBodyPart msgPart = new MimeBodyPart();
msgPart.setContent(msg, msgType + "; charset=" + charset);

Multipart multipart = new MimeMultipart();
multipart.addBodyPart(msgPart);

// Add the attachments:
String attFile;
MimeBodyPart attachment;
Iterator<String> it = new Vector<String>(attachments).iterator();

while (it.hasNext()) {
  attFile = it.next();

  attachment = new MimeBodyPart();
  attachment.setDataHandler(new DataHandler(new AppOctetStreamFileDataSource(attFile)));
  attachment.setFileName(FileUtil.extractFilename(attFile));

  multipart.addBodyPart(attachment);
}

mimeMsg.setContent(multipart);

System.out.println("mail.smtp.ssl.trust: <<" + System.getProperty("mail.smtp.ssl.trust") + ">>");
System.out.println("mail.smtp.ssl.socketfactory.class: <<" + System.getProperty("mail.smtp.ssl.socketfactory.class") + ">>");
System.out.println("mail.smtp.socketfactory.class: <<" + System.getProperty("mail.smtp.socketfactory.class") + ">>");
System.out.println("mail.smtp.ssl.protocols: <<" + System.getProperty("mail.smtp.ssl.protocols") + ">>");
System.out.println("mail.smtp.ssl.ciphersuites: <<" + System.getProperty("mail.smtp.ssl.ciphersuites") + ">>");
System.out.println("SSLContext.getDefault().getDefaultSSLParameters().getProtocols(): "
        + Arrays.toString(SSLContext.getDefault().getDefaultSSLParameters().getProtocols()));
System.out.println("Arrays.toString(SSLContext.getDefault().getDefaultSSLParameters().getCipherSuites(): "
        + Arrays.toString(SSLContext.getDefault().getDefaultSSLParameters().getCipherSuites()));

session.setDebug(debug);
Transport transport = session.getTransport("smtp");
transport.connect(smtpServer, 25, username, pwd);

//System.out.println("#########" + System.getProperty("mail.smtp.localhost"));

transport.sendMessage(mimeMsg, mimeMsg.getAllRecipients());

transport.close();

For debugging I have add some System.out’s for output the some interesting values.

Here the standard output:

DEBUG: JavaMail version 1.4.7
DEBUG: successfully loaded resource: /META-INF/javamail.default.providers
DEBUG: Tables of loaded providers
DEBUG: Providers Listed By Class Name: {com.sun.mail.smtp.SMTPSSLTransport=javax.mail.Provider[TRANSPORT,smtps,com.sun.mail.smtp.SMTPSSLTransport,Oracle], com.sun.mail.smtp.SMTPTransport=javax.mail.Provider[TRANSPORT,smtp,com.sun.mail.smtp.SMTPTransport,Oracle], com.sun.mail.imap.IMAPSSLStore=javax.mail.Provider[STORE,imaps,com.sun.mail.imap.IMAPSSLStore,Oracle], com.sun.mail.pop3.POP3SSLStore=javax.mail.Provider[STORE,pop3s,com.sun.mail.pop3.POP3SSLStore,Oracle], com.sun.mail.imap.IMAPStore=javax.mail.Provider[STORE,imap,com.sun.mail.imap.IMAPStore,Oracle], com.sun.mail.pop3.POP3Store=javax.mail.Provider[STORE,pop3,com.sun.mail.pop3.POP3Store,Oracle]}
DEBUG: Providers Listed By Protocol: {imaps=javax.mail.Provider[STORE,imaps,com.sun.mail.imap.IMAPSSLStore,Oracle], imap=javax.mail.Provider[STORE,imap,com.sun.mail.imap.IMAPStore,Oracle], smtps=javax.mail.Provider[TRANSPORT,smtps,com.sun.mail.smtp.SMTPSSLTransport,Oracle], pop3=javax.mail.Provider[STORE,pop3,com.sun.mail.pop3.POP3Store,Oracle], pop3s=javax.mail.Provider[STORE,pop3s,com.sun.mail.pop3.POP3SSLStore,Oracle], smtp=javax.mail.Provider[TRANSPORT,smtp,com.sun.mail.smtp.SMTPTransport,Oracle]}
DEBUG: successfully loaded resource: /META-INF/javamail.default.address.map
mail.smtp.ssl.trust: <<null>>
mail.smtp.ssl.socketfactory.class: <<null>>
mail.smtp.socketfactory.class: <<null>>
mail.smtp.ssl.protocols: <<null>>
mail.smtp.ssl.ciphersuites: <<null>>
SSLContext.getDefault().getDefaultSSLParameters().getProtocols(): [TLSv1.3, TLSv1.2]
Arrays.toString(SSLContext.getDefault().getDefaultSSLParameters().getCipherSuites(): [TLS_AES_128_GCM_SHA256, TLS_AES_256_GCM_SHA384, TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384, TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384, TLS_RSA_WITH_AES_256_GCM_SHA384, TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384, TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384, TLS_DHE_RSA_WITH_AES_256_GCM_SHA384, TLS_DHE_DSS_WITH_AES_256_GCM_SHA384, TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256, TLS_RSA_WITH_AES_128_GCM_SHA256, TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256, TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256, TLS_DHE_RSA_WITH_AES_128_GCM_SHA256, TLS_DHE_DSS_WITH_AES_128_GCM_SHA256, TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384, TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384, TLS_RSA_WITH_AES_256_CBC_SHA256, TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384, TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384, TLS_DHE_RSA_WITH_AES_256_CBC_SHA256, TLS_DHE_DSS_WITH_AES_256_CBC_SHA256, TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA, TLS_RSA_WITH_AES_256_CBC_SHA, TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA, TLS_ECDH_RSA_WITH_AES_256_CBC_SHA, TLS_DHE_RSA_WITH_AES_256_CBC_SHA, TLS_DHE_DSS_WITH_AES_256_CBC_SHA, TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256, TLS_RSA_WITH_AES_128_CBC_SHA256, TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256, TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256, TLS_DHE_RSA_WITH_AES_128_CBC_SHA256, TLS_DHE_DSS_WITH_AES_128_CBC_SHA256, TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA, TLS_RSA_WITH_AES_128_CBC_SHA, TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA, TLS_ECDH_RSA_WITH_AES_128_CBC_SHA, TLS_DHE_RSA_WITH_AES_128_CBC_SHA, TLS_DHE_DSS_WITH_AES_128_CBC_SHA, TLS_EMPTY_RENEGOTIATION_INFO_SCSV]

And standard error:

javax.net.ssl|DEBUG|01|main|2021-06-10 08:28:39.042 CEST|SSLCipher.java:438|jdk.tls.keyLimits: entry = AES/GCM/NoPadding KeyUpdate 2^37. AES/GCM/NOPADDING:KEYUPDATE = 137438953472
javax.net.ssl|ERROR|01|main|2021-06-10 08:28:39.306 CEST|TransportContext.java:341|Fatal (HANDSHAKE_FAILURE): Couldn't kickstart handshaking (
"throwable" : {
javax.net.ssl.SSLHandshakeException: No appropriate protocol (protocol is disabled or cipher suites are inappropriate)
at java.base/sun.security.ssl.HandshakeContext.(HandshakeContext.java:170)
at java.base/sun.security.ssl.ClientHandshakeContext.(ClientHandshakeContext.java:98)
at java.base/sun.security.ssl.TransportContext.kickstart(TransportContext.java:221)
at java.base/sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:433)
at java.base/sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:411)
at com.sun.mail.util.SocketFetcher.configureSSLSocket(SocketFetcher.java:549)
at com.sun.mail.util.SocketFetcher.startTLS(SocketFetcher.java:486)
at com.sun.mail.smtp.SMTPTransport.startTLS(SMTPTransport.java:1902)
at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:666)
at javax.mail.Service.connect(Service.java:295)
at com.coco_on.tools.general.useCases.net.UCSendEMail.start(UCSendEMail.java:470)
at com.tetrixSystems.tHiddenExecuter.Executer.start(Executer.java:233)
at com.tetrixSystems.tHiddenExecuter.UCMain.start(UCMain.java:83)
at com.tetrixSystems.tHiddenExecuter.UCMain.main(UCMain.java:49)}

)
javax.net.ssl|DEBUG|01|main|2021-06-10 08:28:39.306 CEST|SSLSocketImpl.java:1638|close the underlying socket
javax.net.ssl|DEBUG|01|main|2021-06-10 08:28:39.306 CEST|SSLSocketImpl.java:1657|close the SSL connection (initiative)
javax.mail.MessagingException: Could not convert socket to TLS;
nested exception is:
javax.net.ssl.SSLHandshakeException: No appropriate protocol (protocol is disabled or cipher suites are inappropriate)
at com.sun.mail.smtp.SMTPTransport.startTLS(SMTPTransport.java:1907)
at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:666)
at javax.mail.Service.connect(Service.java:295)
at com.coco_on.tools.general.useCases.net.UCSendEMail.start(UCSendEMail.java:470)
at com.tetrixSystems.tHiddenExecuter.Executer.start(Executer.java:233)
at com.tetrixSystems.tHiddenExecuter.UCMain.start(UCMain.java:83)
at com.tetrixSystems.tHiddenExecuter.UCMain.main(UCMain.java:49)
Caused by: javax.net.ssl.SSLHandshakeException: No appropriate protocol (protocol is disabled or cipher suites are inappropriate)
at java.base/sun.security.ssl.HandshakeContext.(HandshakeContext.java:170)
at java.base/sun.security.ssl.ClientHandshakeContext.(ClientHandshakeContext.java:98)
at java.base/sun.security.ssl.TransportContext.kickstart(TransportContext.java:221)
at java.base/sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:433)
at java.base/sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:411)
at com.sun.mail.util.SocketFetcher.configureSSLSocket(SocketFetcher.java:549)
at com.sun.mail.util.SocketFetcher.startTLS(SocketFetcher.java:486)
at com.sun.mail.smtp.SMTPTransport.startTLS(SMTPTransport.java:1902)
... 6 more

On the Postfix server side, OpenSSL 1.1.1 is installed:

#> openssl version
OpenSSL 1.1.1d  10 Sep 2019

I don’t believe that Java is using OpenSSL internally, but the client side openssl version (CentOS/RHEL 7) may be also interesting:

#> openssl version
OpenSSL 1.0.2k-fips  26 Jan 2017