From cc40af334e619bb549038238507407866f774f8f Mon Sep 17 00:00:00 2001 From: hongbotian Date: Mon, 30 Nov 2015 01:35:09 -0500 Subject: upload apache JIRA: BOTTLENECK-10 Change-Id: I67eae31de6dc824097dfa56ab454ba36fdd23a2c Signed-off-by: hongbotian --- rubbos/app/apache2/manual/ssl/ssl_faq.html.en | 1043 +++++++++++++++++++++++++ 1 file changed, 1043 insertions(+) create mode 100644 rubbos/app/apache2/manual/ssl/ssl_faq.html.en (limited to 'rubbos/app/apache2/manual/ssl/ssl_faq.html.en') diff --git a/rubbos/app/apache2/manual/ssl/ssl_faq.html.en b/rubbos/app/apache2/manual/ssl/ssl_faq.html.en new file mode 100644 index 00000000..16801dd6 --- /dev/null +++ b/rubbos/app/apache2/manual/ssl/ssl_faq.html.en @@ -0,0 +1,1043 @@ + + + +SSL/TLS Strong Encryption: FAQ - Apache HTTP Server + + + + +
+

Modules | Directives | FAQ | Glossary | Sitemap

+

Apache HTTP Server Version 2.0

+
+
<-
+

SSL/TLS Strong Encryption: FAQ

+
+

Available Languages:  en 

+
+ +
+

The wise man doesn't give the right answers, +he poses the right questions.

+

-- Claude Levi-Strauss

+ +
+

This chapter is a collection of frequently asked questions (FAQ) and +corresponding answers following the popular USENET tradition. Most of these +questions occurred on the Newsgroup comp.infosystems.www.servers.unix or the mod_ssl Support +Mailing List modssl-users@modssl.org. They are collected at this place +to avoid answering the same questions over and over.

+ +

Please read this chapter at least once when installing mod_ssl or at least +search for your problem here before submitting a problem report to the +author.

+
+ +
top
+
+

About The Module

+ + +

What is the history of mod_ssl?

+

The mod_ssl v1 package was initially created in April 1998 by Ralf S. Engelschall via porting Ben Laurie's Apache-SSL 1.17 source patches for + Apache 1.2.6 to Apache 1.3b6. Because of conflicts with Ben + Laurie's development cycle it then was re-assembled from scratch for + Apache 1.3.0 by merging the old mod_ssl 1.x with the newer Apache-SSL + 1.18. From this point on mod_ssl lived its own life as mod_ssl v2. The + first publicly released version was mod_ssl 2.0.0 from August 10th, + 1998.

+ +

After US export restrictions on cryptographic software were + loosened, mod_ssl became part of the Apache HTTP + Server with the release of Apache httpd 2.

+ + +

Is mod_ssl affected by the Wassenaar Arrangement?

+

First, let us explain what Wassenaar and its Arrangement on + Export Controls for Conventional Arms and Dual-Use Goods and + Technologies is: This is a international regime, established in 1995, to + control trade in conventional arms and dual-use goods and technology. It + replaced the previous CoCom regime. Further details on + both the Arrangement and its signatories are available at http://www.wassenaar.org/.

+ +

In short, the aim of the Wassenaar Arrangement is to prevent the build up + of military capabilities that threaten regional and international security + and stability. The Wassenaar Arrangement controls the export of + cryptography as a dual-use good, that is, something that has both military and + civilian applications. However, the Wassenaar Arrangement also provides an + exemption from export controls for mass-market software and free software.

+ +

In the current Wassenaar List of Dual Use Goods and Technologies And + Munitions, under GENERAL SOFTWARE NOTE (GSN) it says + The Lists do not control "software" which is either: 1. [...] 2. "in + the public domain". And under DEFINITIONS OF TERMS USED IN + THESE LISTS we find In the public + domain defined as "technology" or "software" which has been made + available without restrictions upon its further dissemination. Note: + Copyright restrictions do not remove "technology" or "software" from being + "in the public domain".

+ +

So, both mod_ssl and OpenSSL are in the public domain for the purposes + of the Wassenaar Arrangement and its List of Dual Use Goods and + Technologies And Munitions List, and thus not affected by its provisions.

+ + +
top
+
+

Installation

+ + +

Why do I get permission errors related to + SSLMutex when I start Apache?

+

Errors such as ``mod_ssl: Child could not open + SSLMutex lockfile /opt/apache/logs/ssl_mutex.18332 (System error follows) + [...] System: Permission denied (errno: 13)'' are usually + caused by overly restrictive permissions on the parent directories. + Make sure that all parent directories (here /opt, + /opt/apache and /opt/apache/logs) have the x-bit + set for, at minimum, the UID under which Apache's children are running (see + the User directive).

+ + +

Why does mod_ssl stop with the error + "Failed to generate temporary 512 bit RSA private key" when I start + Apache?

+

Cryptographic software needs a source of unpredictable data + to work correctly. Many open source operating systems provide + a "randomness device" that serves this purpose (usually named + /dev/random). On other systems, applications have to + seed the OpenSSL Pseudo Random Number Generator (PRNG) manually with + appropriate data before generating keys or performing public key + encryption. As of version 0.9.5, the OpenSSL functions that need + randomness report an error if the PRNG has not been seeded with + at least 128 bits of randomness.

+

To prevent this error, mod_ssl has to provide + enough entropy to the PRNG to allow it to work correctly. This can + be done via the SSLRandomSeed + directive.

+ +
top
+
+

Configuration

+ + +

Is it possible to provide HTTP and HTTPS + from the same server?

+

Yes. HTTP and HTTPS use different server ports (HTTP binds to + port 80, HTTPS to port 443), so there is no direct conflict between + them. You can either run two separate server instances bound to + these ports, or use Apache's elegant virtual hosting facility to + create two virtual servers, both served by the same instance of Apache + - one responding over HTTP to requests on port 80, and the other + responding over HTTPS to requests on port 443.

+ + +

Which port does HTTPS use?

+

You can run HTTPS on any port, but the standards specify port 443, which + is where any HTTPS compliant browser will look by default. You can force + your browser to look on a different port by specifying it in the URL. For + example, if your server is set up to serve pages over HTTPS on port 8080, + you can access them at https://example.com:8080/

+ + +

How do I speak HTTPS manually for testing purposes?

+

While you usually just use

+ +

$ telnet localhost 80
+ GET / HTTP/1.0

+ +

for simple testing of Apache via HTTP, it's not so easy for + HTTPS because of the SSL protocol between TCP and HTTP. With the + help of OpenSSL's s_client command, however, you can + do a similar check via HTTPS:

+ +

$ openssl s_client -connect localhost:443 -state -debug
+ GET / HTTP/1.0

+ +

Before the actual HTTP response you will receive detailed + information about the SSL handshake. For a more general command + line client which directly understands both HTTP and HTTPS, can + perform GET and POST operations, can use a proxy, supports byte + ranges, etc. you should have a look at the nifty + cURL tool. Using this, you can + check that Apache is responding correctly to requests via HTTP and + HTTPS as follows:

+ +

$ curl http://localhost/
+ $ curl https://localhost/

+ + +

Why does the connection hang when I connect + to my SSL-aware Apache server?

+ +

This can happen when you try to connect to a HTTPS server (or virtual + server) via HTTP (eg, using http://example.com/ instead of + https://example.com). It can also happen when trying to + connect via HTTPS to a HTTP server (eg, using + https://example.com/ on a server which doesn't support HTTPS, + or which supports it on a non-standard port). Make sure that you're + connecting to a (virtual) server that supports SSL.

+ +

Why do I get ``Connection Refused'' messages, + when trying to access my newly installed Apache+mod_ssl server via HTTPS?

+

+ This error can be caused by an incorrect configuration. + Please make sure that your Listen directives match your + <VirtualHost> + directives. If all else fails, please start afresh, using the default + configuration provided by mod_ssl.

+ + +

Why are the SSL_XXX variables + not available to my CGI & SSI scripts?

+

Please make sure you have ``SSLOptions +StdEnvVars'' + enabled for the context of your CGI/SSI requests.

+ + +

How can I switch between HTTP and HTTPS in relative + hyperlinks?

+ +

Usually, to switch between HTTP and HTTPS, you have to use + fully-qualified hyperlinks (because you have to change the URL + scheme). Using mod_rewrite however, you can + manipulate relative hyperlinks, to achieve the same effect.

+

+ RewriteEngine on
+ RewriteRule ^/(.*):SSL$ https://%{SERVER_NAME}/$1 [R,L]
+ RewriteRule ^/(.*):NOSSL$ http://%{SERVER_NAME}/$1 [R,L] +

+ +

This rewrite ruleset lets you use hyperlinks of the form + <a href="document.html:SSL">, to switch to HTTPS + in a relative link. (Replace SSL with NOSSL to switch to HTTP.)

+ +
top
+
+

Certificates

+ + +

What are RSA Private Keys, CSRs and Certificates?

+

An RSA private key file is a digital file that you can use to decrypt + messages sent to you. It has a public component which you distribute (via + your Certificate file) which allows people to encrypt those messages to + you.

+

A Certificate Signing Request (CSR) is a digital file which contains + your public key and your name. You send the CSR to a Certifying Authority + (CA), who will convert it into a real Certificate, by signing it.

+

A Certificate contains your + RSA public key, your name, the name of the CA, and is digitally signed by + the CA. Browsers that know the CA can verify the signature on that + Certificate, thereby obtaining your RSA public key. That enables them to + send messages which only you can decrypt.

+

See the Introduction chapter for a general + description of the SSL protocol.

+ + +

Is there a difference on startup between + a non-SSL-aware Apache and an SSL-aware Apache?

+

Yes. In general, starting Apache with + mod_ssl built-in is just like starting Apache + without it. However, if you have a passphrase on your SSL private + key file, a startup dialog will pop up which asks you to enter the + pass phrase.

+ +

Having to manually enter the passphrase when starting the server + can be problematic - for example, when starting the server from the + system boot scripts. In this case, you can follow the steps + below to remove the passphrase from + your private key. Bear in mind that doing so brings additional security + risks - proceed with caution!

+ + +

How do I create a self-signed SSL +Certificate for testing purposes?

+
    +
  1. Make sure OpenSSL is installed and in your PATH.
    +
    +
    2. +
  2. Run the following command, to create server.key and + server.crt files:
    + $ openssl req -new -x509 -nodes -out server.crt + -keyout server.key
    + These can be used as follows in your httpd.conf + file: + 
    +             SSLCertificateFile    /path/to/this/server.crt
+             SSLCertificateKeyFile /path/to/this/server.key
+
    +
    3. +
  3. It is important that you are aware that this + server.key does not have any passphrase. + To add a passphrase to the key, you should run the following + command, and enter & verify the passphrase as requested.
    +

    $ openssl rsa -des3 -in server.key -out + server.key.new
    + $ mv server.key.new server.key

    + Please backup the server.key file, and the passphrase + you entered, in a secure location. +
    4. +
+ + +

How do I create a real SSL Certificate?

+

Here is a step-by-step description:

+
    +
  1. Make sure OpenSSL is installed and in your PATH. +
    +
    +
    2. +
  2. Create a RSA private key for your Apache server + (will be Triple-DES encrypted and PEM formatted):
    +
    + $ openssl genrsa -des3 -out server.key 1024
    +
    + Please backup this server.key file and the + pass-phrase you entered in a secure location. + You can see the details of this RSA private key by using the command:
    + +
    + $ openssl rsa -noout -text -in server.key
    +
    + If necessary, you can also create a decrypted PEM version (not + recommended) of this RSA private key with:
    +
    + $ openssl rsa -in server.key -out server.key.unsecure
    +
    + +
    3. +
  3. Create a Certificate Signing Request (CSR) with the server RSA private + key (output will be PEM formatted):
    +
    + $ openssl req -new -key server.key -out server.csr
    +
    + Make sure you enter the FQDN ("Fully Qualified Domain Name") of the + server when OpenSSL prompts you for the "CommonName", i.e. when you + generate a CSR for a website which will be later accessed via + https://www.foo.dom/, enter "www.foo.dom" here. + You can see the details of this CSR by using
    + +
    + $ openssl req -noout -text -in server.csr
    +
    +
    4. +
  4. You now have to send this Certificate Signing Request (CSR) to + a Certifying Authority (CA) to be signed. Once the CSR has been + signed, you will have a real Certificate, which can be used by + Apache. You can have a CSR signed by a commercial CA, or you can + create your own CA to sign it.
    + Commercial CAs usually ask you to post the CSR into a web form, + pay for the signing, and then send a signed Certificate, which + you can store in a server.crt file. For more information about + commercial CAs see the following locations:
    +
    +
      +
    1. Verisign
      + + http://digitalid.verisign.com/server/apacheNotice.htm + +
      2. +
    2. Thawte
      + http://www.thawte.com/ +
      3. +
    3. CertiSign Certificadora Digital Ltda.
      + + http://www.certisign.com.br + +
      4. +
    4. IKS GmbH
      + + http://www.iks-jena.de/leistungen/ca/ + +
      5. +
    5. Uptime Commerce Ltd.
      + + http://www.uptimecommerce.com + +
      6. +
    6. BelSign NV/SA
      + + http://www.belsign.be + +
      7. +
    + + For details on how to create your own CA, and use this to sign + a CSR, see below.
    + + Once your CSR has been signed, you can see the details of the + Certificate as follows:
    +
    + $ openssl x509 -noout -text -in server.crt
    + +
    5. +
  5. You should now have two files: server.key and + server.crt. These can be used as follows in your + httpd.conf file: + 
    +       SSLCertificateFile    /path/to/this/server.crt
+       SSLCertificateKeyFile /path/to/this/server.key
+
    + The server.csr file is no longer needed. +
    6. + +
+ + +

How do I create and use my own Certificate Authority (CA)?

+

The short answer is to use the CA.sh or CA.pl + script provided by OpenSSL. Unless you have a good reason not to, + you should use these for preference. If you cannot, you can create a + self-signed Certificate as follows:

+ +
    +
  1. Create a RSA private key for your server + (will be Triple-DES encrypted and PEM formatted):
    +
    + $ openssl genrsa -des3 -out server.key 1024
    +
    + Please backup this host.key file and the + pass-phrase you entered in a secure location. + You can see the details of this RSA private key by using the + command:
    + $ openssl rsa -noout -text -in server.key
    +
    + If necessary, you can also create a decrypted PEM version (not + recommended) of this RSA private key with:
    +
    + $ openssl rsa -in server.key -out server.key.unsecure
    +
    +
    2. +
  2. Create a self-signed Certificate (X509 structure) + with the RSA key you just created (output will be PEM formatted):
    +
    + $ openssl req -new -x509 -nodes -sha1 -days 365 + -key server.key -out server.crt
    +
    + This signs the server CSR and results in a server.crt file.
    + You can see the details of this Certificate using:
    +
    + $ openssl x509 -noout -text -in server.crt
    +
    +
    3. +
+ + +

How can I change the pass-phrase on my private key file?

+

You simply have to read it with the old pass-phrase and write it again, + specifying the new pass-phrase. You can accomplish this with the following + commands:

+ + +

$ openssl rsa -des3 -in server.key -out server.key.new
+ $ mv server.key.new server.key

+ +

The first time you're asked for a PEM pass-phrase, you should + enter the old pass-phrase. After that, you'll be asked again to + enter a pass-phrase - this time, use the new pass-phrase. If you + are asked to verify the pass-phrase, you'll need to enter the new + pass-phrase a second time.

+ + +

How can I get rid of the pass-phrase dialog at Apache startup time?

+

The reason this dialog pops up at startup and every re-start + is that the RSA private key inside your server.key file is stored in + encrypted format for security reasons. The pass-phrase is needed to decrypt + this file, so it can be read and parsed. Removing the pass-phrase + removes a layer of security from your server - proceed with caution!

+
    +
  1. Remove the encryption from the RSA private key (while + keeping a backup copy of the original file):
    +
    + $ cp server.key server.key.org
    + $ openssl rsa -in server.key.org -out server.key
    + +
    +
    2. +
  2. Make sure the server.key file is only readable by root:
    +
    + $ chmod 400 server.key
    +
    +
    3. +
+ +

Now server.key contains an unencrypted copy of the key. + If you point your server at this file, it will not prompt you for a + pass-phrase. HOWEVER, if anyone gets this key they will be able to + impersonate you on the net. PLEASE make sure that the permissions on this + file are such that only root or the web server user can read it + (preferably get your web server to start as root but run as another + user, and have the key readable only by root).

+ +

As an alternative approach you can use the ``SSLPassPhraseDialog + exec:/path/to/program'' facility. Bear in mind that this is + neither more nor less secure, of course.

+ + +

How do I verify that a private key matches its Certificate?

+

A private key contains a series of numbers. Two of these numbers form + the "public key", the others are part of the "private key". The "public + key" bits are included when you generate a CSR, and subsequently form + part of the associated Certificate.

+

To check that the public key in your Certificate matches the public + portion of your private key, you simply need to compare these numbers. + To view the Certificate and the key run the commands:

+ +

$ openssl x509 -noout -text -in server.crt
+ $ openssl rsa -noout -text -in server.key

+ +

The `modulus' and the `public exponent' portions in the key and the + Certificate must match. As the public exponent is usually 65537 + and it's difficult to visually check that the long modulus numbers + are the same, you can use the following approach:

+ +

$ openssl x509 -noout -modulus -in server.crt | openssl md5
+ $ openssl rsa -noout -modulus -in server.key | openssl md5

+ +

This leaves you with two rather shorter numbers to compare. It is, + in theory, possible that these numbers may be the same, without the + modulus numbers being the same, but the chances of this are + overwhelmingly remote.

+

Should you wish to check to which key or certificate a particular + CSR belongs you can perform the same calculation on the CSR as + follows:

+ +

$ openssl req -noout -modulus -in server.csr | openssl md5

+ + +

Why do connections fail with an "alert +bad certificate" error?

+

Errors such as OpenSSL: error:14094412: SSL + routines:SSL3_READ_BYTES:sslv3 alert bad certificate in the SSL + logfile, are usually caused by a browser which is unable to handle the server + certificate/private-key. For example, Netscape Navigator 3.x is + unable to handle RSA key lengths not equal to 1024 bits.

+ + +

Why does my 2048-bit private key not work?

+

The private key sizes for SSL must be either 512 or 1024 bits, for compatibility + with certain web browsers. A keysize of 1024 bits is recommended because + keys larger than 1024 bits are incompatible with some versions of Netscape + Navigator and Microsoft Internet Explorer, and with other browsers that + use RSA's BSAFE cryptography toolkit.

+ + +

Why is client authentication broken after upgrading from +SSLeay version 0.8 to 0.9?

+

The CA certificates under the path you configured with + SSLCACertificatePath are found by SSLeay through hash + symlinks. These hash values are generated by the `openssl x509 -noout + -hash' command. However, the algorithm used to calculate the hash for a + certificate changed between SSLeay 0.8 and 0.9. You will need to remove + all old hash symlinks and create new ones after upgrading. Use the + Makefile provided by mod_ssl.

+ + +

How can I convert a certificate from PEM to DER format?

+

The default certificate format for SSLeay/OpenSSL is PEM, which is simply + Base64 encoded DER, with header and footer lines. For some applications + (e.g. Microsoft Internet Explorer) you need the certificate in plain DER + format. You can convert a PEM file cert.pem into the + corresponding DER file cert.der using the following command: + $ openssl x509 -in cert.pem -out cert.der -outform DER

+ + +

Why can't I find the +getca or getverisign programs mentioned by +Verisign, for installing my Verisign certificate?

+

Verisign has never provided specific instructions + for Apache+mod_ssl. The instructions provided are for C2Net's + Stronghold (a commercial Apache based server with SSL support).

+

To install your certificate, all you need to do is to save the + certificate to a file, and give the name of that file to the + SSLCertificateFile directive. + You will also need to give it the key file. For more information, + see the SSLCertificateKeyFile + directive.

+ + +

Can I use the Server Gated Cryptography (SGC) +facility (aka Verisign Global ID) with mod_ssl?

+

Yes. mod_ssl has included support for the SGC + facility since version 2.1. No special configuration is required - + just use the Global ID as your server certificate. The + step up of the clients is then automatically handled by + mod_ssl at run-time.

+ + +

Why do browsers complain that they cannot +verify my Verisign Global ID server certificate?

+

Verisign uses an intermediate CA certificate between the root CA + certificate (which is installed in the browsers) and the server + certificate (which you installed on the server). You should have + received this additional CA certificate from Verisign. + If not, complain to them. Then, configure this certificate with the + SSLCertificateChainFile + directive. This ensures that the intermediate CA certificate is + sent to the browser, filling the gap in the certificate chain.

+ +
top
+
+

The SSL Protocol

+ + +

Why do I get lots of random SSL protocol +errors under heavy server load?

+

There can be a number of reasons for this, but the main one + is problems with the SSL session Cache specified by the + SSLSessionCache directive. The DBM session + cache is the most likely source of the problem, so using the SHM session cache (or + no cache at all) may help.

+ + +

Why does my webserver have a higher load, now +that it serves SSL encrypted traffic?

+

SSL uses strong cryptographic encryption, which necessitates a lot of + number crunching. When you request a webpage via HTTPS, everything (even + the images) is encrypted before it is transferred. So increased HTTPS + traffic leads to load increases.

+ + +

Why do HTTPS connections to my server +sometimes take up to 30 seconds to establish a connection?

+

This is usually caused by a /dev/random device for + SSLRandomSeed which blocks the + read(2) call until enough entropy is available to service the + request. More information is available in the reference + manual for the SSLRandomSeed + directive.

+ + +

What SSL Ciphers are supported by mod_ssl?

+

Usually, any SSL ciphers supported by the version of OpenSSL in use, + are also supported by mod_ssl. Which ciphers are + available can depend on the way you built OpenSSL. Typically, at + least the following ciphers are supported:

+ +
    +
  1. RC4 with MD5
    2. +
  2. RC4 with MD5 (export version restricted to 40-bit key)
    3. +
  3. RC2 with MD5
    4. +
  4. RC2 with MD5 (export version restricted to 40-bit key)
    5. +
  5. IDEA with MD5
    6. +
  6. DES with MD5
    7. +
  7. Triple-DES with MD5
    8. +
+ +

To determine the actual list of ciphers available, you should run + the following:

+

$ openssl ciphers -v

+ + +

Why do I get ``no shared cipher'' errors, when +trying to use Anonymous Diffie-Hellman (ADH) ciphers?

+

By default, OpenSSL does not allow ADH ciphers, for security + reasons. Please be sure you are aware of the potential side-effects + if you choose to enable these ciphers.

+

In order to use Anonymous Diffie-Hellman (ADH) ciphers, you must + build OpenSSL with ``-DSSL_ALLOW_ADH'', and then add + ``ADH'' into your SSLCipherSuite.

+ + +

Why do I get a 'no shared ciphers' +error when connecting to my newly installed server?

+

Either you have made a mistake with your + SSLCipherSuite + directive (compare it with the pre-configured example in + httpd.conf-dist) or you chose to use DSA/DH + algorithms instead of RSA when you generated your private key + and ignored or overlooked the warnings. If you have chosen + DSA/DH, then your server cannot communicate using RSA-based SSL + ciphers (at least until you configure an additional RSA-based + certificate/key pair). Modern browsers like NS or IE can only + communicate over SSL using RSA ciphers. The result is the + "no shared ciphers" error. To fix this, regenerate your server + certificate/key pair, using the RSA algorithm.

+ + +

Why can't I use SSL with name-based/non-IP-based virtual hosts?

+

The reason is very technical, and a somewhat "chicken and egg" problem. + The SSL protocol layer stays below the HTTP protocol layer and + encapsulates HTTP. When an SSL connection (HTTPS) is established + Apache/mod_ssl has to negotiate the SSL protocol parameters with the + client. For this, mod_ssl has to consult the configuration of the virtual + server (for instance it has to look for the cipher suite, the server + certificate, etc.). But in order to go to the correct virtual server + Apache has to know the Host HTTP header field. To do this, the + HTTP request header has to be read. This cannot be done before the SSL + handshake is finished, but the information is needed in order to + complete the SSL handshake phase. Bingo!

+ + +

Why is it not possible to use Name-Based +Virtual Hosting to identify different SSL virtual hosts?

+

Name-Based Virtual Hosting is a very popular method of identifying + different virtual hosts. It allows you to use the same IP address and + the same port number for many different sites. When people move on to + SSL, it seems natural to assume that the same method can be used to have + lots of different SSL virtual hosts on the same server.

+ +

It comes as rather a shock to learn that it is impossible.

+ +

The reason is that the SSL protocol is a separate layer which + encapsulates the HTTP protocol. So the SSL session is a separate + transaction, that takes place before the HTTP session has begun. + The server receives an SSL request on IP address X and port Y + (usually 443). Since the SSL request does not contain any Host: + field, the server has no way to decide which SSL virtual host to use. + Usually, it will just use the first one it finds, which matches the + port and IP address specified.

+ +

You can, of course, use Name-Based Virtual Hosting to identify many + non-SSL virtual hosts (all on port 80, for example) and then + have a single SSL virtual host (on port 443). But if you do this, + you must make sure to put the non-SSL port number on the NameVirtualHost + directive, e.g.

+ +

+ NameVirtualHost 192.168.1.1:80 +

+ +

Other workaround solutions include:

+ +

Using separate IP addresses for different SSL hosts. + Using different port numbers for different SSL hosts.

+ + +

How do I get SSL compression working?

+

Although SSL compression negotiation was defined in the specification +of SSLv2 and TLS, it took until May 2004 for RFC 3749 to define DEFLATE as +a negotiable standard compression method. +

+

OpenSSL 0.9.8 started to support this by default when compiled with the +zlib option. If both the client and the server support compression, +it will be used. However, most clients still try to initially connect with an +SSLv2 Hello. As SSLv2 did not include an array of prefered compression algorithms +in its handshake, compression cannot be negotiated with these clients. +If the client disables support for SSLv2, either an SSLv3 or TLS Hello +may be sent, depending on which SSL library is used, and compression may +be set up. You can verify whether clients make use of SSL compression by +logging the %{SSL_COMPRESS_METHOD}x variable. +

+ + +

When I use Basic Authentication over HTTPS +the lock icon in Netscape browsers stays unlocked when the dialog pops up. +Does this mean the username/password is being sent unencrypted?

+

No, the username/password is transmitted encrypted. The icon in + Netscape browsers is not actually synchronized with the SSL/TLS layer. + It only toggles to the locked state when the first part of the actual + webpage data is transferred, which may confuse people. The Basic + Authentication facility is part of the HTTP layer, which is above + the SSL/TLS layer in HTTPS. Before any HTTP data communication takes + place in HTTPS, the SSL/TLS layer has already completed its handshake + phase, and switched to encrypted communication. So don't be + confused by this icon.

+ + +

Why do I get I/O errors when connecting via +HTTPS to an Apache+mod_ssl server with Microsoft Internet Explorer (MSIE)?

+

The first reason is that the SSL implementation in some MSIE versions has + some subtle bugs related to the HTTP keep-alive facility and the SSL close + notify alerts on socket connection close. Additionally the interaction + between SSL and HTTP/1.1 features are problematic in some MSIE versions. + You can work around these problems by forcing Apache not to use HTTP/1.1, + keep-alive connections or send the SSL close notify messages to MSIE clients. + This can be done by using the following directive in your SSL-aware + virtual host section:

+

+ SetEnvIf User-Agent ".*MSIE.*" \
+ nokeepalive ssl-unclean-shutdown \
+ downgrade-1.0 force-response-1.0 +

+

Further, some MSIE versions have problems with particular ciphers. + Unfortunately, it is not possible to implement a MSIE-specific + workaround for this, because the ciphers are needed as early as the + SSL handshake phase. So a MSIE-specific + SetEnvIf won't solve these + problems. Instead, you will have to make more drastic + adjustments to the global parameters. Before you decide to do + this, make sure your clients really have problems. If not, do not + make these changes - they will affect all your clients, MSIE + or otherwise.

+ +

The next problem is that 56bit export versions of MSIE 5.x + browsers have a broken SSLv3 implementation, which interacts badly + with OpenSSL versions greater than 0.9.4. You can accept this and + require your clients to upgrade their browsers, you can downgrade to + OpenSSL 0.9.4 (not advised), or you can work around this, accepting + that your workaround will affect other browsers too:

+

SSLProtocol all -SSLv3

+

will completely disables the SSLv3 protocol and allow those + browsers to work. A better workaround is to disable only those + ciphers which cause trouble.

+

SSLCipherSuite + ALL:!ADH:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv2:+EXP +

+ +

This also allows the broken MSIE versions to work, but only removes the + newer 56bit TLS ciphers.

+ +

Another problem with MSIE 5.x clients is that they refuse to connect to + URLs of the form https://12.34.56.78/ (where IP-addresses are used + instead of the hostname), if the server is using the Server Gated + Cryptography (SGC) facility. This can only be avoided by using the fully + qualified domain name (FQDN) of the website in hyperlinks instead, because + MSIE 5.x has an error in the way it handles the SGC negotiation.

+ +

And finally there are versions of MSIE which seem to require that + an SSL session can be reused (a totally non standard-conforming + behaviour, of course). Connecting with those MSIE versions only work + if a SSL session cache is used. So, as a work-around, make sure you + are using a session cache (see the SSLSessionCache directive).

+ + +

Why do I get I/O errors, or the message "Netscape has +encountered bad data from the server", when connecting via +HTTPS to an Apache+mod_ssl server with Netscape Navigator?

+

+ This usually occurs when you have created a new server certificate for + a given domain, but had previously told your browser to always accept + the old server certificate. Once you clear the entry for the old + certificate from your browser, everything should be fine. Netscape's SSL + implementation is correct, so when you encounter I/O errors with Netscape + Navigator it is usually caused by the configured certificates.

+ +
top
+
+

mod_ssl Support

+ + +

What information resources are available in case of mod_ssl problems?

+

The following information resources are available. + In case of problems you should search here first.

+ +
+
Answers in the User Manual's F.A.Q. List (this)
+
+ http://httpd.apache.org/docs/2.0/ssl/ssl_faq.html
+ First check the F.A.Q. (this text). If your problem is a common + one, it may have been answered several times before, and been included + in this doc. +
+
Postings from the modssl-users Support Mailing List + http://www.modssl.org/support/
+
Search for your problem in the archives of the modssl-users mailing list. + You're probably not the first person to have had this problem! +
+
+ + +

What support contacts are available in case +of mod_ssl problems?

+

The following lists all support possibilities for mod_ssl, in order of + preference. Please go through these possibilities + in this order - don't just pick the one you like the look of.

+
    +
  1. Send a Problem Report to the modssl-users Support Mailing List
    + + modssl-users@modssl.org
    + This is the preferred way of submitting your problem report, because this way, + others can see the problem, and learn from any answers. You must subscribe to + the list first, but you can then easily discuss your problem with both the + author and the whole mod_ssl user community. +
    2. + +
  2. Send a Problem Report to the Apache httpd Users Support Mailing List
    + + users@httpd.apache.org
    + This is the second way of submitting your problem report. Again, you must + subscribe to the list first, but you can then easily discuss your problem + with the whole Apache httpd user community. +
    3. + +
  3. Write a Problem Report in the Bug Database
    + + http://httpd.apache.org/bug_report.html
    + This is the last way of submitting your problem report. You should only + do this if you've already posted to the mailing lists, and had no success. + Please follow the instructions on the above page carefully. +
    4. +
+ + +

What information should I +provide when writing a bug report?

+

You should always provide at least the following information:

+ +
+
Apache and OpenSSL version information
+
The Apache version can be determined + by running httpd -v. The OpenSSL version can be + determined by running openssl version. Alternatively, if + you have Lynx installed, you can run the command lynx -mime_header + http://localhost/ | grep Server to gather this information in a + single step. +
+ +
The details on how you built and installed Apache+mod_ssl+OpenSSL
+
For this you can provide a logfile of your terminal session which shows + the configuration and install steps. If this is not possible, you + should at least provide the configure command line you used. +
+ +
In case of core dumps please include a Backtrace
+
If your Apache+mod_ssl+OpenSSL dumps its core, please attach + a stack-frame ``backtrace'' (see below + for information on how to get this). This information is required + in order to find a reason for your core dump. +
+ +
A detailed description of your problem
+
Don't laugh, we really mean it! Many problem reports don't + include a description of what the actual problem is. Without this, + it's very difficult for anyone to help you. So, it's in your own + interest (you want the problem be solved, don't you?) to include as + much detail as possible, please. Of course, you should still include + all the essentials above too. +
+
+ + +

I had a core dump, can you help me?

+

In general no, at least not unless you provide more details about the code + location where Apache dumped core. What is usually always required in + order to help you is a backtrace (see next question). Without this + information it is mostly impossible to find the problem and help you in + fixing it.

+ + +

How do I get a backtrace, to help find +the reason for my core dump?

+

Following are the steps you will need to complete, to get a backtrace:

+
    +
  1. Make sure you have debugging symbols available, at least + in Apache. On platforms where you use GCC/GDB, you will have to build + Apache+mod_ssl with ``OPTIM="-g -ggdb3"'' to get this. On + other platforms at least ``OPTIM="-g"'' is needed. +
    2. + +
  2. Start the server and try to reproduce the core-dump. For this you may + want to use a directive like ``CoreDumpDirectory /tmp'' to + make sure that the core-dump file can be written. This should result + in a /tmp/core or /tmp/httpd.core file. If you + don't get one of these, try running your server under a non-root UID. + Many modern kernels do not allow a process to dump core after it has + done a setuid() (unless it does an exec()) for + security reasons (there can be privileged information left over in + memory). If necessary, you can run /path/to/httpd -X + manually to force Apache to not fork. +
    3. + +
  3. Analyze the core-dump. For this, run gdb /path/to/httpd + /tmp/httpd.core or a similar command. In GDB, all you + have to do then is to enter bt, and voila, you get the + backtrace. For other debuggers consult your local debugger manual. +
    4. +
+ +
+
+

Available Languages:  en 

+
+ \ No newline at end of file -- cgit 1.2.3-korg