Package: libnss3 Version: 2:3.19-1 Severity: normal Dear Maintainer,
since upgrade to NSS 3.19.1, icedove refuses to connect to an IMAPS server with a "Server Temp Key: DH, 768 bits". Workaround is to downgrade to NSS 3.19 or change icedove connection to unencrypted IMAP. To protect against logjam attacks, NSS 3.19.1 refuses to connect to servers with a finite field algorithm key strength less than 1023 bits: https://developer.mozilla.org/en- US/docs/Mozilla/Projects/NSS/NSS_3.19.1_release_notes This behaviour breaks icedove on Debian clients that need to connect to IMAPS servers with weak server temp keys. Note that these are clients which have no control over configuration of remote servers. Workaround is to downgrade to NSS 3.19 or change icedove connection to unencrypted IMAP. Kind regards, Ben. Upgrade that caused the failure: libnss3-1d:amd64 (3.19-1, 3.19.1-2), libnss3:amd64 (3.19-1, 3.19.1-2) icedove error console: Error: An error occurred during a connection to mail.example.org:993. SSL received a weak ephemeral Diffie-Hellman key in Server Key Exchange handshake message. (Error code: ssl_error_weak_server_ephemeral_dh_key) Affected server openssl s_client session showing server temp key (note: icedove manual exception added for broken certs): $ openssl s_client -connect ub007lcs04.cbr.the-server.net.au:993 CONNECTED(00000003) depth=0 C = US, ST = NY, L = New York, O = Courier Mail Server, OU = Automatically-generated IMAP SSL key, CN = localhost, emailAddress = postmas...@example.com verify error:num=18:self signed certificate verify return:1 depth=0 C = US, ST = NY, L = New York, O = Courier Mail Server, OU = Automatically-generated IMAP SSL key, CN = localhost, emailAddress = postmas...@example.com verify error:num=10:certificate has expired notAfter=Nov 18 06:02:36 2014 GMT verify return:1 depth=0 C = US, ST = NY, L = New York, O = Courier Mail Server, OU = Automatically-generated IMAP SSL key, CN = localhost, emailAddress = postmas...@example.com notAfter=Nov 18 06:02:36 2014 GMT verify return:1 --- Certificate chain 0 s:/C=US/ST=NY/L=New York/O=Courier Mail Server/OU=Automatically-generated IMAP SSL key/CN=localhost/emailAddress=postmas...@example.com i:/C=US/ST=NY/L=New York/O=Courier Mail Server/OU=Automatically-generated IMAP SSL key/CN=localhost/emailAddress=postmas...@example.com --- Server certificate -----BEGIN CERTIFICATE----- MIIC/zCCAmigAwIBAgIJAJh1IPFs6+cSMA0GCSqGSIb3DQEBBQUAMIG1MQswCQYD VQQGEwJVUzELMAkGA1UECBMCTlkxETAPBgNVBAcTCE5ldyBZb3JrMRwwGgYDVQQK ExNDb3VyaWVyIE1haWwgU2VydmVyMS0wKwYDVQQLEyRBdXRvbWF0aWNhbGx5LWdl bmVyYXRlZCBJTUFQIFNTTCBrZXkxEjAQBgNVBAMTCWxvY2FsaG9zdDElMCMGCSqG SIb3DQEJARYWcG9zdG1hc3RlckBleGFtcGxlLmNvbTAeFw0xMzExMTgwNjAyMzZa Fw0xNDExMTgwNjAyMzZaMIG1MQswCQYDVQQGEwJVUzELMAkGA1UECBMCTlkxETAP BgNVBAcTCE5ldyBZb3JrMRwwGgYDVQQKExNDb3VyaWVyIE1haWwgU2VydmVyMS0w KwYDVQQLEyRBdXRvbWF0aWNhbGx5LWdlbmVyYXRlZCBJTUFQIFNTTCBrZXkxEjAQ BgNVBAMTCWxvY2FsaG9zdDElMCMGCSqGSIb3DQEJARYWcG9zdG1hc3RlckBleGFt cGxlLmNvbTCBnzANBgkqhkiG9w0BAQEFAAOBjQAwgYkCgYEAwy9JZbZkl3t8HZX3 mKipZZ45Ol4CJJHrdrOMmWXNXk3dAClrs5yJiPmMOA2s9ruexp0aYBKb056m5HfX LUVumnkLSLYUOrhpSYaM/qI4w6rU7X02pHjBynX7kubaTNiPD5OTtp3+C+ZYURdd BsK9iuW8dfkzG0jFtJBMRSR6B1MCAwEAAaMVMBMwEQYJYIZIAYb4QgEBBAQDAgZA MA0GCSqGSIb3DQEBBQUAA4GBAJ3jKR/R6Ferrg+DT2rnPQyu/ahsElnVRj2VtWCy D/AIOSg8T98CfDWUjnZxe5LOaNB4X0VKVh2sEwZYMViCgtPM9v5jXgREsHUUNEaT Wn1ZF17BS3gx70PoLtob6C9yEhERzw3OAIDXVHVBSADK+imSxyxENHv+hUiEoNJw Xz81 -----END CERTIFICATE----- subject=/C=US/ST=NY/L=New York/O=Courier Mail Server/OU=Automatically-generated IMAP SSL key/CN=localhost/emailAddress=postmas...@example.com issuer=/C=US/ST=NY/L=New York/O=Courier Mail Server/OU=Automatically-generated IMAP SSL key/CN=localhost/emailAddress=postmas...@example.com --- No client certificate CA names sent Peer signing digest: SHA512 Server Temp Key: DH, 768 bits --- SSL handshake has read 1424 bytes and written 503 bytes --- New, TLSv1/SSLv3, Cipher is DHE-RSA-AES256-GCM-SHA384 Server public key is 1024 bit Secure Renegotiation IS supported Compression: NONE Expansion: NONE No ALPN negotiated SSL-Session: Protocol : TLSv1.2 Cipher : DHE-RSA-AES256-GCM-SHA384 Session-ID: 1458FA1DBEEA2D465D47D3E2B49ED7DAE09C625E5CE84CCFFC4B0C29FFC9A7F7 Session-ID-ctx: Master-Key: 3880E699567D8B9A2D59BB2809A4D97AA2F88264543B130C47B245BE292D3AE2873D002C06F2155EE5C1A9FA5E7D77AA Key-Arg : None PSK identity: None PSK identity hint: None SRP username: None TLS session ticket lifetime hint: 7200 (seconds) TLS session ticket: 0000 - a4 50 46 e6 9e ce 75 4d-33 7e 60 af 50 21 bf 50 .PF...uM3~`.P!.P 0010 - 62 07 ac f1 1d 55 f0 7a-d2 ce 24 1b 81 06 f1 dc b....U.z..$..... 0020 - d3 f4 99 4d 6c 9a 78 36-87 a2 a5 0c 86 48 0c 91 ...Ml.x6.....H.. 0030 - 0f e6 c2 8f 02 ae 4e d8-14 0a a7 e3 18 17 15 e7 ......N......... 0040 - fa 67 22 65 7f 5c 53 97-8e a1 c4 05 2a 56 d1 2f .g"e.\S.....*V./ 0050 - 03 b4 e2 78 1b d7 94 60-13 48 71 32 3e b9 2d 49 ...x...`.Hq2>.-I 0060 - 74 57 08 c9 0c 3c b1 90-3d b2 93 d2 7a 1f f8 ee tW...<..=...z... 0070 - 7a 9d 4e de 23 7a b7 6b-6b 9d 2a ce bc 98 53 e6 z.N.#z.kk.*...S. 0080 - 6c aa d5 99 94 ef b4 0e-ab 2d 8b 6b 1b eb cd bc l........-.k.... 0090 - 52 57 67 49 dd bd 2a 8a-da 21 7c be ba 61 7f bc RWgI..*..!|..a.. Start Time: 1433239095 Timeout : 300 (sec) Verify return code: 10 (certificate has expired) --- * OK [CAPABILITY IMAP4rev1 UIDPLUS CHILDREN NAMESPACE THREAD=ORDEREDSUBJECT THREAD=REFERENCES SORT QUOTA IDLE AUTH=PLAIN ACL ACL2=UNION] Courier-IMAP ready. Copyright 1998-2011 Double Precision, Inc. See COPYING for distribution information. DONE -- System Information: Debian Release: stretch/sid APT prefers unstable APT policy: (500, 'unstable') Architecture: amd64 (x86_64) Foreign Architectures: i386 Kernel: Linux 4.0.0-1-amd64 (SMP w/4 CPU cores) Locale: LANG=en_GB.utf8, LC_CTYPE=en_GB.utf8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash Init: systemd (via /run/systemd/system) Versions of packages libnss3 depends on: ii libc6 2.19-18 ii libnspr4 2:4.10.8-2 ii libsqlite3-0 3.8.10.2-1 ii zlib1g 1:1.2.8.dfsg-2+b1 libnss3 recommends no packages. libnss3 suggests no packages. -- no debconf information -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
