Apache 2 Supports Ssl // Tls: Step by Step Instructions (Part Ii)

This updated guide examines Apache 2 Supports Ssl // Tls: Step by Step Instructions (Part Ii) and organizes the essential facts, background, and practical takeaways in clear American English.

Review Part I

InstructionSetting requirements orSSLEngineannotations Must be enabled, otherwise the server (or virtual client) will not use SSL / TLS to be enabled by SSLRequireSSL . Web content can be accessed via regular HTTP requests without requiring SSL / TLS. SSLProtocol SSLProxyProtocol It is recommended to set the mode to use only TLS v1.0 and SSL v3.0. Most web browsers currently support both. So we can safely disable SSL v2.0. SSLCipherSuite SSLProxyCipherSuite To create a strong encryption method, this parameter should be set to HIGH (> 168 bits) and MEDIUM (128 bits). LOW level ( HIGH: MEDIUM:! ANULL: + SHA1: + MD5: + HIGH: + MEDIUM Note : The settings that support the encoder can be viewed as follows: openssl ciphers -v 'HIGH: MEDIUM:! aNULL: + SHA1: + MD5: + HIGH: + MEDIUM' SSLOptions The "+ StrictRequire" option should be set, otherwise the "Satisfy Any" directive can force mod_ssl to allow Access web content even if SSL / TLS is not used. SSLRandomSeed To start Apache, install it to use fake random device (/ dev / urandom) and / or EGD (Entrophy Gathering Daemon). Before each new SSL connection is established, reconfigure it to use the pre-installed source, / dev / urandom or EGD. Do not use / dev / random in either case. Because / dev / random can only provide many entropy at a given time. SSLSessionCache To avoid repeating SSL handshakes for parallel HTTP requests (for example, when web browser loads multiple images over a period of time), SSL caching should be used. It will set up to use shared memory (SHM), or DBM. When this setting is "none", the execution of the internet server can be significantly reduced. SSLSessionCacheTimeout This value describes the number of seconds seconds after the entry in SSLSessionCache expires. It should be set at least 300-600 seconds. However, real-time depends on the average user time spent on each visit to the internet server. For example, if the average time is about 15 minutes, then the value should be set to at least 900 (15 minutes * 60 seconds). SSLVerifyClient SSLProxyVerify When not using client or proxy identifiers, these options should be set to 'none'. Never put them in "optional_no_ca" mode. Because in contrast to PKI identifiers, where the client is identified, they must present the appropriate certificates. 'Optional' is sometimes used (depending on whether it is needed or not), however it may not work for all web browsers. SSLVerifyDepth SSLProxyVerifyDepth Should be the largest number of intermediate CAs. For example, to get only self-signed certificates, set it to 0, for client certificates signed by Root CA, set to 1. SSLProxyEngine should be disabled (set to disable), if SSL mechanism / TLS proxy cannot be used.

Table 1. Required settings for mod_ssl .

Our sample settings corresponding to the above instructions can be found in httpd.conf as follows:

SSLEngine on SSLOptions + StrictRequire SSLRequireSSL SSLProtocol -all + TLSv1 + SSLv3 # Support only for strong cryptography SSLCipherSuite HIGH: MEDIUM:! ANULL: + SHA1: + MD5: + HIGH: + MEDIUM # Support for strong and export cryptography # SSLCipherSuite HIGH: MEDIUM: EXP:! ANULL: + SHA1: + MD5: + HIGH: + MEDIUM: + EXP SSLRandomSeed startup file: / dev / urandom 1024 SSL Randomization file: / dev / urandom 1024 SSLSessionCache shm: / usr / local / apache2 / logs / ssl_cache_shm SSLSessionCacheTimeout 600 SSLVerify none SSLProxyEngine off

In addition to the instructions on mod_ssl above, there are two other important parts in Apache modules ( mod_log_config and mod_set_envif ) that need to be installed according to the following table 2:

InstructionRequired setting or commenting CustomLog To write SSL parameter information (minimum requirement: version of protocol and encoder selected) we should use the following values: CustomLog logs / ssl_request_log "% t% h% {HTTPS} x% {SSL_PROTOCOL} x% {SSL_CIPHER} x % {SSL_CIPHER_USEKEYSIZE} x% {SSL_CLIENT_VERIFY} x "% r"% b " Setenvif To be compatible with older versions of MS Internet Explorer with errors in the SSL execution section (eg problems with keep-alive functions, HTTP 1.1 on SSL, alerted scenes) close SSL on the connection end socket The following options should be set: SetEnvIf User-Agent ". * MSIE. *" nokeepalive ssl-unclean-shutdown downgrade-1.0 force-response-1.0 The above option causes the internet server to use HTTP / 1.1 or keep-alive connections and will not send SSL close attention when the internet browser is MS Internet Explorer.

Table 2. Setting requirements for mod_log and mod_set_envif .

The sample configuration file (httpd.conf) shown in the previous lesson has included the above options, making it more convenient for readers. Web server identifier So far, we can configure and test SSL / TLS, but our web browser cannot check the identity of the internet server. In the first lesson, we used a web server certificate created for testing purposes and did not contain the information required for real identity and commercial transactions. In order for web browser to successfully identify the internet server, we need to create an appropriate web server certificate, which should include:

• Common key for web server
• Effective date (start date and expiration date)
• Support encryption algorithms
• A separate set of names (DN), must include the full valid domain name of the internet server, known as the common name (CN). However, there may be other components such as country (C), state (S), region (L), organization name (O), organizational unit name (OU) or more.
• Number of certificate numbers
• The X.509v3 attribute will tell the internet browser about the type and usage of the certificate
• URI of CRL distribution point (if exists)
• URI of X.509v3 Certificate Policy (if exists)
• The name and signature are verified by the certificate identifier (CA).

It is important to note that the common name attribute (CN) must be a fully qualified domain name on the internet server. Otherwise the internet browser will not be able to verify that the certificate belongs to the internet server that is being used. Web server certificate template (text style template) can be as follows:

Certificate: Data: Version: 3 (0x2) Serial Number: 1 (0x1) Signature Algorithm: sha1WithRSAEncryption Issuer: O = Seccure, OU = Seccure Root CA Validity Not Before: Nov 28 01:00:20 2004 GMT Not After: Nov 28 01:00:20 2005 GMT Subject: O = Seccure, OU = Seccure Labs, CN = www.seccure.lab

Subject Public Key Info: Public Key Algorithm: rsaEncryption RSA Public Key: (1024 bits) Modulus (1024 bits): 00: 1: 19: c7: 38: f4: 89: 91: 27: a2: 1b: 1d: b6: 8d: 91: 48: 63: 0e: 3d: 0d: 2e: f8: 65: 45: 56: db: 98: 4d: 11: 21: 01: ac: 81: 8e: 3f: 64: 4a: 8a: 3f: 21: 15: ca: 49: 6e: 64: 5c: 5d: a2: ab: 5a: 48: cb: 2a: 9f: 0c: 02: b9: ff: 52: f6: d9: 39: 6d: a3: 4a: 94: 41: f9: e9: ab: f0: 42: fb: 68: 9a: 4b: 53: 41: e7: 4f: b0: 2b: 02: d7: 92: a2: 2b: 02: a2: f9: f1: 2d: 68: fa: 50: 01: 2f: 49: c1: 28: 2f: a8: c6: 6d: 6d: ab: 1d: b9: bd: c9: 80: 63: f1: d6: 22: 19: de: 2d: 4a: 43: 50: 76: 79: 7e: a5: 5a: 75: af: 19 Exponent: 65537 (0x10001) X509v3 extensions: X509v3 Basic Constraints: CA: FALSE Netscape Cert Type: SSL Server X509v3 Key Usage: Digital Signature, Key Encipherment X509v3 Extended Key Usage: TLS Web Server Authentication, Netscape Server Gated Crypto, Microsoft Server Gated Crypto Netscape Comment: OpenSSL Certificate for SSL Web Server Signature Algorithm: sha1WithRSAEncryption 45: 30: 9d: 04: 0e: b7: 86: 9e: 61: a1: b0: 68: 2b: 44: 93: 1c: 57: 2a: 99: 42: bb: 16: b1: ab: f5: c0: d2: 33: 12: c8: d3: 1d: 2b: bb: 6b: 9a: 4c: c7: 53: bc: e4: 88: ef: 1e: c3: 37: ed: 53: 2c: 15: cf: b8: 90: df: df: 4b: 34: b8: db: cc: 23: 77: 46: 06: 72: 9d: 43: 60: a8: a2: ed: 0a: bb: 1a: a4: e8: 4e: three: 66: 93: 63: 74: 87: fd: 43: 48: b6: 93: a2: e3: 3d: da: 1b: 64: 46: 35: 88: b4: 4b: 22: e6: 3c: 84: 70: 5d: 88: dd: 64: c2: 51: c2: d6: 59: 80: 87: bc: bd: 7f: e3: c1: 45: 7e: c0: 5f: 9c: ca: e1: a1

The next example is based on some values shown in Table 3. To create a correct certificate, you need to replace some of these values with your company or organization name:

Description attributeAttributeExample Country code (2 characters) C C = PL State or province S S = mazowieckie Region L L = Warsaw Organization name O O = Seccure Organization unit OU OU = Seccure Labs Common name CN CN = www.seccure.lab

Table 3 . Example of a correct certificate

Should a password be used to protect it? Before starting to create certificates, it's important to understand the meaning of the password (passphrase) in the certificate. Should the internet server's private keys be encrypted? There are many opinions, including the idea that it is not recommended to protect the private key with a password. It is not only inconvenient but also creates a feeling of insecurity. Why? See the following points: 1. First, it requires entering the password after each restart of the internet server. This is quite annoying if the system needs to reboot regularly (such as updating code, an electronic error or configuration changes, etc.). 2. If an intruder conquers and retrieves the private key on the internet server, it means that the internet server is compromised and the intruder has access to the internet server's operating system in Root. In this case, the intruder can steal the password by installing a keylogger. And then, either destroy or restart the system to force the administrator to re-enter the password. The intruder can dump Apache's memory and find the internet server's private key stored in a certain segment. Therefore, improving the internet server's private key encryption with passwords only helps protect them against children. As for the system vandalists, it is useless. Create a web server certificate In this section we can create web server certificates. Usually there are 3 types of certificates that we can use:

Self-signed certificate (self-signed certificate) 2. Certificate certified by CA (most) 3. The certificate is signed by the internal CA

The following section describes in detail how to create the above certificates. The end result of any method used will have only 2 files:

• server.key - the internet server's private key
• server.crt - PEM encryption certificate including the internet browser public key

Method 1 : Self-signed certificate (for testing purposes only) This method is designed only to continue our testing process, or to use it in a small, close environment (such as at home or a small Intranets network). In order for the internet browser to identify the internet server the self-signed certificate must be installed in every web browser that needs to access that web server. This can be quite inconvenient. the internet server's public / private key pair and PEM self-signed encryption certificate can be created as follows:

openssl req -new -x509 -days 365 -sha1 -newkey rsa: 1024 -nodes -keyout server.key -out server.crt -subj '/ O = Seccure / OU = Seccure Labs / CN = www.seccure.lab'

The above statements will create a new certificate (-new), named (-x509), which is valid for one year (-days 365), and will be signed by using the SHA1 algorithm (-sha1). The RSA private key is 1024 bits long (-newkey rsa: 10224), and does not need to be protected with a (-nodes) password. The certificate and the public / private key pair will be created in two files 'server.crt' and 'server.key'. The name of this area is 'Seccure Labs' and the full domain name is: www.seccure.lab. After creating the above certificate, we need to distribute and install it in any web browser that can connect to the internet server. Otherwise, when the internet browser requires a connection, it will not be able to verify the identity of the internet server. In a Windows environment, this is shown in Figure 1 below:

Method 2 : Certificate signed by CA Creating a certificate request and signing it with a trusted CA (such as Versign, Thawte, RSA, etc.) is the most commonly used way to know if an SSL web server is included in the internet. Using this approach does not need to install the certificate in every web browser. Because most of them have a number of CA certificates from before they are installed. Note that each certificate authority (CA) has different limits for distributing proper names, providing lengths for a key, international characters. Therefore, before creating certification requirements you need to make sure that your certification requirements are consistent with the specific requirements of CA. Should choose a CA whose signed certificates are installed in most web browsers (including: Thawte, Verisgn and some other firms.). Otherwise, the user's web browser may have problems verifying with the internet server. The process of obtaining a signed certificate by a trusted CA includes the following steps: 1. The first step is to create a public / private key pair (in server.key) and certificate request (in request.pem) as follows:

openssl req -new -sha1 -newkey rsa: 1024 -nodes -keyout server.key -out request.pem -subj '/ O = Seccure / OU = Seccure Labs / CN = www.seccure.lab'

2. Now we have to send the certificate request to CA (in request.pem ). Then wait until it is signed and return to us the form of the certificate. 3. After receiving the certificate from the trusted CA , we must make sure that it has been encoded in PEM format and not TXT or DER. If you receive a certificate that does not encode PEM, you need to convert from any format received to PEM format. The easiest way to check the format of the certificate is to view the certificate with a text editor. Depending on which editor we have one of the following formats (the file name extension is indicated in double quotes): - PEM, Base64 encoded X.509 format (*.crt, *.pem, *.cer)

----- BEGIN CERTIFICATE ----- MIICdzCCAeCgAwIBAgIBATANBgkqhkiG9w0BAQUFADAsMRAwDgYDVQQKEwdTZWNj dXJlMRgwFgYDVQQLEw9TZWNjdXJlIFJvb3QgQ0EwHhcNMDQxMTI4MDEwMDIwWhcN . ou0Kuxqk6E66ZpNjdIf9Q0i2k6LjPdobZEY1iLRLIuY8hHBdiN1kwlHC1lmAh7y9 f + PBRX7AX5zK4aE = ----- END CERTIFICATE -----

- TXT + PEM format (*.crt, *.cer, *.pem, *.txt)

Certificate: Data: Version: 3 (0x2) Serial Number: 1 (0x1) Signature Algorithm: sha1WithRSAEncryption Issuer: O = Seccure, OU = Seccure Root CA . RSA Public Key: (1024 bits) Modulus (1024 bits): 00: 1: 19: c7: 38: f4: 89: 91: 27: a2: 1b: 1d: b6: 8d: 91: . X509v3 extensions: X509v3 Basic Constraints: CA: FALSE . ----- BEGIN CERTIFICATE ----- MIICdzCCAeCgAwIBAgIBATANBgkqhkiG9w0BAQUFADAsMRAwDgYDVQQKEwdTZWNj dXJlMRgwFgYDVQQLEw9TZWNjdXJlIFJvb3QgQ0EwHhcNMDQxMTI4MDEwMDIwWhcN . ou0Kuxqk6E66ZpNjdIf9Q0i2k6LjPdobZEY1iLRLIuY8hHBdiN1kwlHC1lmAh7y9 f + PBRX7AX5zK4aE = ----- END CERTIFICATE -----

- If your certificate is received as TXT + PEM, here is the command to convert it to PEM:

openssl x509 -in signed_cert.pem -out server.crt

- DER, encoded binary encoded X.509 (*.der, *.crt, *.cer)

[non-text, binary representation]

- If your certificate is received as DER, the switch to PEM is:

openssl x509 -in signed_cert.der -inform DER -out server.crt

4. Verify and check the certificate Before installing the certificate, we should check to see if the certificate is actually valid and can be used to authenticate the internet server:

openssl verify -CAfile /path/to/trusted_ca.crt -purpose sslserver server.crt

Likewise, if it runs well, make sure that the certificate corresponds to the previously created web server's private key (the results of both statements are identical):

openssl x509 -noout -modulus -in server.crt | openssl sha1 openssl rsa -noout -modulus -in server.key | openssl sha1

( Also )