Memory Not Enough

星期四, 10月 26, 2017

Install Oracle 11g missing package pdksh-5.2.14 issue

RHEL6 安裝 Oracle 11g 遭遇 pdksh-5.2.14 不存在
http://blog.roodo.com/oraksumi/archives/41081323.html

原因在於 OUI 在進行環境檢查時執行的是下列 command :
----------------------------------------------------------------------------------------
/bin/rpm -q --qf %{version} redhat-release
----------------------------------------------------------------------------------------
在 RHEL6 的環境下 redhat-release 已經被取代為 redhat-release-server-6Server，因此上述 command 會造成了缺少 "elfutils-libelf-devel-0.97" 或是 "pdksh-5.2.14" Package 的錯誤。

解決方式於安裝介質目錄下 database/stage/cvu/cv/admin 找出 cvu_config 這個檔案並且編輯他，將其中的 CV_ASSUME_DISTID=OEL4 改為 CV_ASSUME_DISTID=OEL6 ，如此一來 OUI 便可以正確的檢查系統所需的 Package 了。

由於 "elfutils-libelf-devel-0.97" 或是 "pdksh-5.2.14" 這兩個 Package 並不是必要的，若不想更動 cvu_config 這個檔案，那麼在安裝過程中忽略這個錯誤就可以了。

http://blog.roodo.com/oraksumi/archives/41081323.html

星期四, 10月 05, 2017

IBM MQ FAQ for Long Term Support and Continuous Delivery releases

http://www-01.ibm.com/support/docview.wss?uid=swg27047919

星期二, 10月 03, 2017

IHS and WAS fix for CVE-2016-2183

For IHS:

IBM HTTP Server and Sweet32: Birthday attack (CVE-2016-2183)

http://www-01.ibm.com/support/docview.wss?uid=swg21991548

For WAS:

Security Bulletin: Multiple vulnerabilities in IBM® Java SDK affects WebSphere Application Server January 2017 CPU

http://www-01.ibm.com/support/docview.wss?uid=swg21998379

星期四, 9月 21, 2017

How to find out user id and SID mapping

PsGetSid
https://docs.microsoft.com/zh-tw/sysinternals/downloads/psgetsid

Security Identifier(SID): GetSID of a user,object using Registry, WMIC, PowerShell
https://blogs.msdn.microsoft.com/gaurav/2014/06/03/security-identifiersid-getsid-of-a-userobject-using-registry-wmic-powershell/

wmic useraccount where (name='administrator' and domain='gauravtestMachine') get name,sid

Name SID
administrator S-1-5-21-1976753858-2077894621-3616986626-500

星期二, 9月 19, 2017

MQ client failed to connect qmgr with 2539 error

https://www.ibm.com/support/knowledgecenter/en/SSFKSJ_9.0.0/com.ibm.mq.tro.doc/q045390_.htm

2539 (09EB) (RC2539): MQRC_CHANNEL_CONFIG_ERROR

ExplanationAn MQCONN call was issued from a client to connect to a queue manager but the attempt to establish communication failed. Common causes of this reason code are:(1) The server and client cannot agree on the channel attributes to use.(2) There are errors in one or both of the QM.INI or MQCLIENT.INI configuration files.(3) The server machine does not support the code page used by the client.

注意﹕非常容易忘記(3)也可能造成無法連線, 從error 的文字訊息不易想到

星期二, 9月 05, 2017

How can I test if my server supports a specific SSL protocol?

1. Linux command line tool:
openssl can help you test which SSL protocols your server is configured to use.
openssl

If a protocol is enabled, the openssl s_client command will wait for input (or Control-D).
If the protocol is disabled, openssl will report an exception similiar to the one reproduced below:
21112:error:1407F0E5:SSL routines:SSL2_WRITE:ssl handshake failure:s2_pkt.c:428:

Openssl examples:
openssl s_client -connect ihshostname:443 -ssl2
openssl s_client -connect ihshostname:443 -ssl3
openssl s_client -connect ihshostname:443 -tls1

#openssl s_client -connect www.google.com:443 -ssl3
CONNECTED(00000003)
23569:error:1408F10B:SSL routines:SSL3_GET_RECORD:wrong version number:s3_pkt.c:293:

#openssl s_client -connect localhost:1414 -cipher ECDHE-RSA-DES-CBC3-SHA

#openssl s_client -connect localhost:1414 -showcerts

#openssl ciphers ==> 列出openssl可用的cipher名稱, 以:分隔

**** perl one liner 可用在此處, 把原本用:分隔不易查看的資訊, 改以每筆一行的方式列出

#openssl ciphers|perl -ne 's/:/\n/g;print'

2. online website check tool
https://www.ssllabs.com/ssltest/

3. standalone test tool (TestSSLServer)
https://www.bolet.org/TestSSLServer/

4. IHS v8 or above version command:
Windows:
httpd -t -D DUMP_SSL_CONFIG
Linux:
apachectl -t -D DUMP_SSL_CONFIG

http://publib.boulder.ibm.com/httpserv/ihsdiag/ssl_questions.html#sslprotsupptest

5. use nmap to help to verify which cipherspec is supported by SSL server

nmap --script ssl-enum-ciphers -p port_number ip_address

# nmap --script ssl-enum-ciphers -p 1477 localhost
Starting Nmap 7.70 ( https://nmap.org ) at 2019-06-03 10:56 CST
Nmap scan report for localhost (127.0.0.1)
Host is up (0.00018s latency).
Other addresses for localhost (not scanned): ::1

PORT STATE SERVICE
1477/tcp open ms-sna-server
| ssl-enum-ciphers:
| TLSv1.0:
| ciphers:
| TLS_RSA_WITH_AES_128_CBC_SHA (rsa 1024) - A
| TLS_RSA_WITH_AES_256_CBC_SHA (rsa 1024) - A
| compressors:
| NULL
| cipher preference: server
| TLSv1.2:
| ciphers:
| TLS_RSA_WITH_AES_128_CBC_SHA256 (rsa 1024) - A
| TLS_RSA_WITH_AES_256_CBC_SHA256 (rsa 1024) - A
| TLS_RSA_WITH_AES_128_GCM_SHA256 (rsa 1024) - A
| TLS_RSA_WITH_AES_256_GCM_SHA384 (rsa 1024) - A
| TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 (secp256r1) - A
| TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 (secp384r1) - A
| TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (secp256r1) - A
| TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (secp384r1) - A
| compressors:
| NULL
| cipher preference: server
|_ least strength: A

Nmap done: 1 IP address (1 host up) scanned in 1.63 seconds

Ref:

SSL 相關的測試工具

https://www.qa-knowhow.com/?p=3888

SSL handshake concept:
https://support.f5.com/csp/article/K15292

星期四, 8月 24, 2017

Perl — Calculate timing difference in microseconds

Time::Piece has been in core since 5.10.


use Time::Piece;

sub str2time {
    my ($str) = @_;
    $str =~ s/(\.[0-9]+)?\z//;
    my $fraction = $1 || 0;
    return Time::Piece->strptime($str, '%Y-%m-%d %H:%M:%S')->epoch + $fraction;
}

my $t1 = str2time('2013-12-27 13:28:14.975952');
my $t2 = str2time('2013-12-27 13:28:16.345667');

printf "difference: %f\n", $t2 - $t1;

https://stackoverflow.com/questions/20851081/perl-calculate-timing-difference-in-microseconds

This can be used to analyze the trace for performance issue.

Note:

|| if the left operand is true, the right operand is not even evaluated.

\z Match only at end of string

? Match 1 or 0 times
$var =~ s/A/B/
把變數 $var 內的第一個A子字串整個代換成B子字串。特別注意第一部份(A)為RE, 但第二部分(B)僅為字串

http://irw.ncut.edu.tw/peterju/perl.html

$str =~ s/(\.[0-9]+)?\z// => 表示將小數點後(含小數點)的部分用空字串取代, 也就是移除
$fraction = $1 || 0 => 表示若有找到小數點後的部分, 即把其值copy 給fraction, 不然就設為0

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