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 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 to jdk.tls.legacyAlgorithms. Here are the interesting settings from java.security:
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
Maybe I'm blind, but I don't see where my problem is…
OK, at first, I removed my extensions from jdk.tls.legacyAlgorithms, because these are not helpful and wrong (thanks to dave_thompson_085 for the hint).
Here is the Java code for sending the emails (the code has a "long" history, so please don't wonder why it uses Vector instead of ArrayList, etc.)
// 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 added some System.out's to output some interesting values.
Here is 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
After upgrading JavaMail from 1.4.7 to 1.6.2, the error is gone! I'm sure there are also other clients which use JavaMail 1.4.7 and which works. So there must also be another difference on that machine. However, now it works!