The description below uses the variable name $CATALINABASE to refer thebase directory against which most relative paths are resolved. If you havenot configured Tomcat for multiple instances by setting a CATALINABASEdirectory, then $CATALINABASE will be set to the value of $CATALINAHOME,the directory into which you have installed Tomcat.To install and configure SSL/TLS support on Tomcat, you need to followthese simple steps. For more information, read the rest of this HOW-TO.Create a keystore file to store the server's private key andself-signed certificate by executing the following command:Windows. Transport Layer Security (TLS) and its predecessor, Secure Sockets Layer(SSL), are technologies which allow web browsers and web servers to communicateover a secured connection.

1. Mysql Ssl Certificate Location
2. Error: Ssl Context Is Not Usable Without Certificate And Private Key Code
3. Mysql 5.7 Ssl Windows

This means that the data being sent is encrypted byone side, transmitted, then decrypted by the other side before processing.This is a two-way process, meaning that both the server AND the browser encryptall traffic before sending out data.Another important aspect of the SSL/TLS protocol is Authentication. This meansthat during your initial attempt to communicate with a web server over a secureconnection, that server will present your web browser with a set ofcredentials, in the form of a 'Certificate', as proof the site is who and whatit claims to be. In certain cases, the server may also request a Certificatefrom your web browser, asking for proof that you are who you claimto be.

This is known as 'Client Authentication,' although in practice this isused more for business-to-business (B2B) transactions than with individualusers. Most SSL-enabled web servers do not request Client Authentication. SSL/TLS and Tomcat. It is important to note that configuring Tomcat to take advantage ofsecure sockets is usually only necessary when running it as a stand-aloneweb server.

Details can be found in the.When running Tomcat primarily as a Servlet/JSP container behindanother web server, such as Apache or Microsoft IIS, it is usually necessaryto configure the primary web server to handle the SSL connections from users.Typically, this server will negotiate all SSL-related functionality, thenpass on any requests destined for the Tomcat container only after decryptingthose requests. Likewise, Tomcat will return cleartext responses, that willbe encrypted before being returned to the user's browser. In this environment,Tomcat knows that communications between the primary web server and theclient are taking place over a secure connection (because your applicationneeds to be able to ask about this), but it does not participate in theencryption or decryption itself.

SSL/TLS Strong Encryption: FAQ. Available Languages: en fr. 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.

In order to implement SSL, a web server must have an associated Certificatefor each external interface (IP address) that accepts secure connections.The theory behind this design is that a server should provide some kind ofreasonable assurance that its owner is who you think it is, particularlybefore receiving any sensitive information. While a broader explanation ofCertificates is beyond the scope of this document, think of a Certificate as a'digital passport' for an Internet address.

It states which organisation thesite is associated with, along with some basic contact information about thesite owner or administrator.This certificate is cryptographically signed by its owner, and istherefore extremely difficult for anyone else to forge. For the certificate towork in the visitors browsers without warnings, it needs to be signed by atrusted third party. These are called Certificate Authorities (CAs). Toobtain a signed certificate, you need to choose a CA and follow the instructionsyour chosen CA provides to obtain your certificate. A range of CAs is availableincluding some that offer certificates at no cost.Java provides a relatively simple command-line tool, calledkeytool, which can easily create a 'self-signed' Certificate.Self-signed Certificates are simply user generated Certificates which have notbeen signed by a well-known CA and are, therefore, not really guaranteed to beauthentic at all.

While self-signed certificates can be useful for some testingscenarios, they are not suitable for any form of production use. General Tips on Running SSL. When securing a website with SSL it's important to make sure that all assetsthat the site uses are served over SSL, so that an attacker can't bypassthe security by injecting malicious content in a javascript file or similar. Tofurther enhance the security of your website, you should evaluate to use theHSTS header.

It allows you to communicate to the browser that your site shouldalways be accessed over https.Using name-based virtual hosts on a secured connection requires carefulconfiguration of the names specified in a single certificate or Tomcat 8.5onwards where Server Name Indication (SNI) support is available. SNI allowsmultiple certificates with different names to be associated with a single TLSconnector.

Tomcat currently operates only on JKS, PKCS11 orPKCS12 format keystores. The JKS formatis Java's standard 'Java KeyStore' format, and is the format created by thekeytool command-line utility. This tool is included in the JDK.The PKCS12 format is an internet standard, and can be manipulatedvia (among other things) OpenSSL and Microsoft's Key-Manager.Each entry in a keystore is identified by an alias string. Whilst manykeystore implementations treat aliases in a case insensitive manner, casesensitive implementations are available. The PKCS11 specification,for example, requires that aliases are case sensitive.

To avoid issues relatedto the case sensitivity of aliases, it is not recommended to use aliases thatdiffer only in case.To import an existing certificate into a JKS keystore, please read thedocumentation (in your JDK documentation package) about keytool.Note that OpenSSL often adds readable comments before the key, butkeytool does not support that. So if your certificate hascomments before the key data, remove them before importing the certificate withkeytool.To import an existing certificate signed by your own CA into a PKCS12keystore using OpenSSL you would execute a command like.

$JAVAHOME/bin/keytool -genkey -alias tomcat -keyalg RSA(The RSA algorithm should be preferred as a secure algorithm, and thisalso ensures general compatibility with other servers and components.)This command will create a new file, in the home directory of the userunder which you run it, named '.keystore'. To specify adifferent location or filename, add the -keystore parameter,followed by the complete pathname to your keystore file,to the keytool command shown above. You will also need toreflect this new location in the server.xml configuration file,as described later.

For example:Windows. $JAVAHOME/bin/keytool -genkey -alias tomcat -keyalg RSA-keystore /path/to/my/keystoreAfter executing this command, you will first be prompted for the keystorepassword. The default password used by Tomcat is ' changeit'(all lower case), although you can specify a custom password if you like.You will also need to specify the custom password in theserver.xml configuration file, as described later.Next, you will be prompted for general information about this Certificate,such as company, contact name, and so on. This information will be displayedto users who attempt to access a secure page in your application, so makesure that the information provided here matches what they will expect.Finally, you will be prompted for the key password, which is thepassword specifically for this Certificate (as opposed to any otherCertificates stored in the same keystore file). The keytool promptwill tell you that pressing the ENTER key automatically uses the same passwordfor the key as the keystore. You are free to use the same password or to selecta custom one.

If you select a different password to the keystore password, youwill also need to specify the custom password in the server.xmlconfiguration file.If everything was successful, you now have a keystore file with aCertificate that can be used by your server. Tomcat can use three different implementations of SSL:.

JSSE implementation provided as part of the Java runtime. JSSE implementation that uses OpenSSL. APR implementation, which uses the OpenSSL engine by defaultThe exact configuration details depend on which implementation is being used.If you configured Connector by specifying genericprotocol='HTTP/1.1' then the implementation used by Tomcat ischosen automatically. If the installation uses- i.e. You have installed the Tomcat native library -then it will use the JSSE OpenSSL implementation, otherwise it will use the JavaJSSE implementation.Auto-selection of implementation can be avoided if needed. It is done by specifying a classnamein the protocol attribute of the.To define a Java (JSSE) connector, regardless of whether the APR library isloaded or not, use one of the following.

An example elementfor an SSL connector is included in the default server.xmlfile installed with Tomcat. To configure an SSL connector that uses JSSE, youwill need to remove the comments and edit it so it looks something likethis.

The NIO and NIO2 connectors use JSSE unless the JSSE OpenSSL implementation isinstalled (in which case it supports either the JSSE or OpenSSL configuration styles),whereas the APR/native connector uses APR.The port attribute is the TCP/IPport number on which Tomcat will listen for secure connections. You canchange this to any port number you wish (such as to the default port forhttps communications, which is 443). However, special setup(outside the scope of this document) is necessary to run Tomcat on portnumbers lower than 1024 on many operating systems.If you change the port number here, you should also change thevalue specified for the redirectPort attribute on thenon-SSL connector. This allows Tomcat to automatically redirectusers who attempt to access a page with a security constraint specifyingthat SSL is required, as required by the Servlet Specification.After completing these configuration changes, you must restart Tomcat asyou normally do, and you should be in business. You should be able to accessany web application supported by Tomcat via SSL. For example, try. Now that you have your Certificate you can import it into you local keystore.First of all you have to import a so called Chain Certificate or Root Certificate into your keystore.After that you can proceed with importing your Certificate.

Download a Chain Certificate from the Certificate Authority you obtained the Certificate from.For Verisign.com commercial certificates go to:Verisign.com trial certificates go to:Trustcenter.de go to:Thawte.com go to:Import the Chain Certificate into your keystore. Omitted for brevityx509x509extensions = v3issuedv3issuedsubjectKeyIdentifier=hashauthorityKeyIdentifier=keyid,issuer# The address of your responderauthorityInfoAccess = OCSP;URI:= critical,digitalSignature,nonRepudiation,keyEncipherment,dataEncipherment,keyAgreement,keyCertSign,cRLSign,encipherOnly,decipherOnlybasicConstraints=critical,CA:FALSEnsComment='Testing OCSP Certificate'#. Omitted for brevityThe settings above encode the OCSP responder address127.0.0.1:8088 into the certificate. Note that for the followingsteps, you must have openssl.cnf and other configuration ofyour CA ready. To generate an OCSP-enabled certificate:.Create a private key. This is a new feature in the Servlet 3.0 specification. Because it uses theSSL session ID associated with the physical client-server connection thereare some limitations.

Mysql Ssl Certificate Location

They are:. Tomcat must have a connector with the attributeisSecure set to true.

If SSL connections are managed by a proxy or a hardware acceleratorthey must populate the SSL request headers (see the) so thatthe SSL session ID is visible to Tomcat. If Tomcat terminates the SSL connection, it will not be possible to usesession replication as the SSL session IDs will be different on eachnode.To enable SSL session tracking you need to use a context listener to set thetracking mode for the context to be just SSL (if any other tracking mode isenabled, it will be used in preference). It might look something like. // Standard HTTP session invalidationsession.invalidate;// Invalidate the SSL Sessionorg.apache.tomcat.util.net.SSLSessionManager mgr =(org.apache.tomcat.util.net.SSLSessionManager)request.getAttribute('javax.servlet.request.sslsessionmgr');mgr.invalidateSession;// Close the connection since the SSL session will be active until the connection// is closedresponse.setHeader('Connection', 'close');Note that this code is Tomcat specific due to the use of theSSLSessionManager class. This is currently only available for the NIO andNIO2 connectors, not the APR/native connector.

WarningDon’t use this module without reading the. Doing somay lead to a false sense of security, as the default settings of thessl module are not necessarily appropriate for your application.This section documents the objects and functions in the ssl module; for moregeneral information about TLS, SSL, and certificates, the reader is referred tothe documents in the “See Also” section at the bottom.This module provides a class, which is derived from thetype, and provides a socket-like wrapper that alsoencrypts and decrypts the data going over the socket with SSL. It supportsadditional methods such as getpeercert, which retrieves thecertificate of the other side of the connection, and cipher,whichretrieves the cipher being used for the secure connection.For more sophisticated applications, the classhelps manage settings and certificates, which can then be inheritedby SSL sockets created through the method.

NoteWhich connections succeed will vary depending on the version ofOpenSSL. For example, before OpenSSL 1.0.0, an SSLv23 clientwould always attempt SSLv2 connections.The ciphers parameter sets the available ciphers for this SSL object.It should be a string in the.The parameter dohandshakeonconnect specifies whether to do the SSLhandshake automatically after doing a socket.connect, or whether theapplication program will call it explicitly, by invoking themethod. Callingexplicitly gives the program control over theblocking behavior of the socket I/O involved in the handshake.The parameter suppressraggedeofs specifies how theSSLSocket.recv method should signal unexpected EOF from the other endof the connection. If specified as (the default), it returns anormal EOF (an empty bytes object) in response to unexpected EOF errorsraised from the underlying socket; if, it will raise theexceptions back to the caller. Context creationA convenience function helps create objects for commonpurposes. Createdefaultcontext ( purpose=Purpose.SERVERAUTH, cafile=None, capath=None, cadata=None )Return a new object with default settings forthe given purpose. The settings are chosen by the module,and usually represent a higher security level than when calling theconstructor directly.cafile, capath, cadata represent optional CA certificates totrust for certificate verification, as in.

If all three are, this function can choose to trust the system’s defaultCA certificates instead.The settings are:, andwith high encryption cipher suites without RC4 andwithout unauthenticated cipher suites. Passingas purpose sets toand either loads CA certificates (when at least one of cafile, capath orcadata is given) or uses to loaddefault CA certificates. New in version 3.3.

RANDpseudobytes ( num )Return (bytes, iscryptographic): bytes are num pseudo-random bytes,iscryptographic is True if the bytes generated are cryptographicallystrong. Raises an if the operation is not supported by thecurrent RAND method.Generated pseudo-random byte sequences will be unique if they are ofsufficient length, but are not necessarily unpredictable.

They can be usedfor non-cryptographic purposes and for certain purposes in cryptographicprotocols, but usually not for key generation etc.For almost all applications is preferable. New in version 3.3. RANDstatus ( )Return True if the SSL pseudo-random number generator has been seededwith ‘enough’ randomness, and False otherwise. You can useand to increase the randomness ofthe pseudo-random number generator. RANDegd ( path )If you are running an entropy-gathering daemon (EGD) somewhere, and pathis the pathname of a socket connection open to it, this will read 256 bytesof randomness from the socket, and add it to the SSL pseudo-random numbergenerator to increase the security of generated secret keys. This istypically only necessary on systems without better sources of randomness.See or for sourcesof entropy-gathering daemons. RANDadd ( bytes, entropy )Mix the given bytes into the SSL pseudo-random number generator.

Theparameter entropy (a float) is a lower bound on the entropy contained instring (so you can always use 0.0). See for moreinformation on sources of entropy. Certificate handling ssl.

Matchhostname ( cert, hostname )Verify that cert (in decoded format as returned by) matches the given hostname. The rulesapplied are those for checking the identity of HTTPS servers as outlinedin and, except that IP addresses are not currentlysupported. In addition to HTTPS, this function should be suitable forchecking the identity of servers in various SSL-based protocols such asFTPS, IMAPS, POPS and others.is raised on failure. On success, the functionreturns nothing. Changed in version 3.3.3: The function now follows, section 6.4.3 and does neithermatch multiple wildcards (e.g.com or.a.example.org) nora wildcard inside an internationalized domain names (IDN) fragment.IDN A-labels such as www.xn-pthon-kva.org are still supported,but x.python.org no longer matches xn-tda.python.org.

Certtimetoseconds ( timestring )Returns a floating-point value containing a normal seconds-after-the-epochtime value, given the time-string representing the “notBefore” or “notAfter”date from a certificate.Here’s an example. import ssl ssl. Certtimetoseconds ( 'May 9 00: GMT' ).0 import time time. Certtimetoseconds ( 'May 9 00: GMT' )) 'Wed May 9 00:' ssl.

Getservercertificate ( addr, sslversion=PROTOCOLSSLv3, cacerts=None )Given the address addr of an SSL-protected server, as a ( hostname,port-number) pair, fetches the server’s certificate, and returns it as aPEM-encoded string. If sslversion is specified, uses that version ofthe SSL protocol to attempt to connect to the server. If cacerts isspecified, it should be a file containing a list of root certificates, thesame format as used for the same parameter in. The callwill attempt to validate the server certificate against that set of rootcertificates, and will fail if the validation attempt fails.

Changed in version 3.3: This function is now IPv6-compatible. DERcerttoPEMcert ( DERcertbytes )Given a certificate as a DER-encoded blob of bytes, returns a PEM-encodedstring version of the same certificate. PEMcerttoDERcert ( PEMcertstring )Given a certificate as an ASCII PEM string, returns a DER-encoded sequence ofbytes for that same certificate. Getdefaultverifypaths ( )Returns a named tuple with paths to OpenSSL’s default cafile and capath.The paths are the same as used.

The return value is aDefaultVerifyPaths:. cafile - resolved path to cafile or None if the file doesn’t exist,. capath - resolved path to capath or None if the directory doesn’t exist,.

opensslcafileenv - OpenSSL’s environment key that points to a cafile,. opensslcafile - hard coded path to a cafile,. opensslcapathenv - OpenSSL’s environment key that points to a capath,. opensslcapath - hard coded path to a capath directory. New in version 3.4. Enumcertificates ( storename )Retrieve certificates from Windows’ system cert store.

Storename may beone of CA, ROOT or MY. Windows may provide additional certstores, too.The function returns a list of (certbytes, encodingtype, trust) tuples.The encodingtype specifies the encoding of certbytes. It is eitherx509asn for X.509 ASN.1 data or pkcs7asn forPKCS#7 ASN.1 data. Trust specifies the purpose of the certificate as a setof OIDS or exactly True if the certificate is trustworthy for allpurposes.Example. Constants ssl.

CERTNONEPossible value for, or the certreqsparameter to. In this mode (the default), nocertificates will be required from the other side of the socket connection.If a certificate is received from the other end, no attempt to validate itis made.See the discussion of below. CERTOPTIONALPossible value for, or the certreqsparameter to. In this mode no certificates will berequired from the other side of the socket connection; but if theyare provided, validation will be attempted and anwill be raised on failure.Use of this setting requires a valid set of CA certificates tobe passed, either to or as avalue of the cacerts parameter to. CERTREQUIREDPossible value for, or the certreqsparameter to. In this mode, certificates arerequired from the other side of the socket connection; anwill be raised if no certificate is provided, or if its validation fails.Use of this setting requires a valid set of CA certificates tobe passed, either to or as avalue of the cacerts parameter to.

VERIFYDEFAULTPossible value for. In this mode, certificaterevocation lists (CRLs) are not checked. By default OpenSSL does neitherrequire nor verify CRLs. SSL Sockets class ssl. SSLSocket ( socket.socket )SSL sockets provide the following methods of:.,.,.,.,(but passing a non-zero flags argument is not allowed)., (withthe same limitation).However, since the SSL (and TLS) protocol has its own framing atopof TCP, the SSL sockets abstraction can, in certain respects, diverge fromthe specification of normal, OS-level sockets. See especially the.Usually, are not created directly, but using thefunction or the method.SSL sockets also have the following additional methods and attributes: SSLSocket.

Read ( len=0, buffer=None )Read up to len bytes of data from the SSL socket and return the result asa bytes instance. If buffer is specified, then read into the bufferinstead, and return the number of bytes read.Raise or if the socket isand the read would block.As at any time a re-negotiation is possible, a call to can alsocause write operations. Write ( buf )Write buf to the SSL socket and return the number of bytes written.

Thebuf argument must be an object supporting the buffer interface.Raise or if the socket isand the write would block.As at any time a re-negotiation is possible, a call to canalso cause read operations. Changed in version 3.4: The handshake method also performs when theattribute of the socket’sis true.

Getpeercert ( binaryform=False )If there is no certificate for the peer on the other end of the connection,return None. If the SSL handshake hasn’t been done yet, raise.If the binaryform parameter is, and a certificate wasreceived from the peer, this method returns a instance.

If thecertificate was not validated, the dict is empty. If the certificate wasvalidated, it returns a dict with several keys, amongst them subject(the principal for which the certificate was issued) and issuer(the principal issuing the certificate). If a certificate contains aninstance of the Subject Alternative Name extension (see ),there will also be a subjectAltName key in the dictionary.The subject and issuer fields are tuples containing the sequenceof relative distinguished names (RDNs) given in the certificate’s datastructure for the respective fields, and each RDN is a sequence ofname-value pairs.

Here is a real-world example. NoteTo validate a certificate for a particular service, you can use thefunction.If the binaryform parameter is, and a certificate wasprovided, this method returns the DER-encoded form of the entire certificateas a sequence of bytes, or if the peer did not provide acertificate. Whether the peer provides a certificate depends on the SSLsocket’s role:. for a client SSL socket, the server will always provide a certificate,regardless of whether validation was required;. for a server SSL socket, the client will only provide a certificatewhen requested by the server; therefore will returnif you used (rather thanor ).

Changed in version 3.4: is raised when the handshake isn’t done.The returned dictionary includes additional X509v3 extension itemssuch as crlDistributionPoints, caIssuers and OCSP URIs. Cipher ( )Returns a three-value tuple containing the name of the cipher being used, theversion of the SSL protocol that defines its use, and the number of secretbits being used. If no connection has been established, returns None. Compression ( )Return the compression algorithm being used as a string, or Noneif the connection isn’t compressed.If the higher-level protocol supports its own compression mechanism,you can use to disable SSL-level compression.

New in version 3.3. Unwrap ( )Performs the SSL shutdown handshake, which removes the TLS layer from theunderlying socket, and returns the underlying socket object. This can beused to go from encrypted operation over a connection to unencrypted. Thereturned socket should always be used for further communication with theother side of the connection, rather than the original socket. Pending ( )Returns the number of already decrypted bytes available for read, pending onthe connection.

Error: Ssl Context Is Not Usable Without Certificate And Private Key Code

ContextThe object this SSL socket is tied to. If the SSLsocket was created using the top-level function(rather than ), this is a custom contextobject created for this SSL socket. New in version 3.2.An SSL context holds various data longer-lived than single SSL connections,such as SSL configuration options, certificate(s) and private key(s).It also manages a cache of SSL sessions for server-side sockets, in orderto speed up repeated connections from the same clients. SSLContext ( protocol )Create a new SSL context. You must pass protocol which must be oneof the PROTOCOL. constants defined in this module.is currently recommended for maximuminteroperability.

Mysql 5.7 Ssl Windows

New in version 3.4. Loadcertchain ( certfile, keyfile=None, password=None )Load a private key and the corresponding certificate. The certfilestring must be the path to a single file in PEM format containing thecertificate as well as any number of CA certificates needed to establishthe certificate’s authenticity. The keyfile string, if present, mustpoint to a file containing the private key in. Otherwise the privatekey will be taken from certfile as well. See the discussion offor more information on how the certificateis stored in the certfile.The password argument may be a function to call to get the password fordecrypting the private key.

It will only be called if the private key isencrypted and a password is necessary. It will be called with no arguments,and it should return a string, bytes, or bytearray.

If the return value isa string it will be encoded as UTF-8 before using it to decrypt the key.Alternatively a string, bytes, or bytearray value may be supplied directlyas the password argument. It will be ignored if the private key is notencrypted and no password is needed.If the password argument is not specified and a password is required,OpenSSL’s built-in password prompting mechanism will be used tointeractively prompt the user for a password.An is raised if the private key doesn’tmatch with the certificate. Changed in version 3.3: New optional argument password. Loaddefaultcerts ( purpose=Purpose.SERVERAUTH )Load a set of default “certification authority” (CA) certificates fromdefault locations.

On Windows it loads CA certs from the CA andROOT system stores. On other systems it calls. In the future the method mayload CA certificates from other locations, too.The purpose flag specifies what kind of CA certificates are loaded. Thedefault settings loads certificates, that areflagged and trusted for TLS web server authentication (client sidesockets). Loads CA certificates for clientcertificate verification on the server side. New in version 3.4.

Loadverifylocations ( cafile=None, capath=None, cadata=None )Load a set of “certification authority” (CA) certificates used to validateother peers’ certificates when is other than. At least one of cafile or capath must be specified.This method can also load certification revocation lists (CRLs) in PEM orDER format. In order to make use of CRLs,must be configured properly.The cafile string, if present, is the path to a file of concatenatedCA certificates in PEM format. See the discussion offor more information about how to arrange thecertificates in this file.The capath string, if present, isthe path to a directory containing several CA certificates in PEM format,following an.The cadata object, if present, is either an ASCII string of one or morePEM-encoded certificates or a of DER-encodedcertificates. Like with capath extra lines around PEM-encodedcertificates are ignored but at least one certificate must be present. New in version 3.4. Setdefaultverifypaths ( )Load a set of default “certification authority” (CA) certificates froma filesystem path defined when building the OpenSSL library.

Unfortunately,there’s no easy way to know whether this method succeeds: no error isreturned if no certificates are to be found. When the OpenSSL library isprovided as part of the operating system, though, it is likely to beconfigured properly. Setciphers ( ciphers )Set the available ciphers for sockets created with this context.It should be a string in the.If no cipher can be selected (because compile-time options or otherconfiguration forbids use of all the specified ciphers), anwill be raised. Notewhen connected, the method of SSL sockets willgive the currently selected cipher. Setnpnprotocols ( protocols )Specify which protocols the socket should advertise during the SSL/TLShandshake.

It should be a list of strings, like 'http/1.1', 'spdy/2',ordered by preference. The selection of a protocol will happen during thehandshake, and will play out according to the. After asuccessful handshake, the method willreturn the agreed-upon protocol.This method will raise if isFalse. New in version 3.3. Setservernamecallback ( servernamecallback )Register a callback function that will be called after the TLS Client Hellohandshake message has been received by the SSL/TLS server when the TLS clientspecifies a server name indication.

The server name indication mechanismis specified in section 3 - Server Name Indication.Only one callback can be set per SSLContext. If servernamecallbackis None then the callback is disabled. Calling this function asubsequent time will disable the previously registered callback.The callback function, servernamecallback, will be called with threearguments; the first being the, the second is a stringthat represents the server name that the client is intending to communicate(or if the TLS Client Hello does not contain a server name)and the third argument is the original. The server nameargument is the IDNA decoded server name.A typical use of this callback is to change the ‘sattribute to a new object of typerepresenting a certificate chain that matches the servername.Due to the early negotiation phase of the TLS connection, only limitedmethods and attributes are usable likeand.,and SSLSocket.compress methods require thatthe TLS connection has progressed beyond the TLS Client Hello and thereforewill not contain return meaningful values nor can they be called safely.The servernamecallback function must return None to allow theTLS negotiation to continue. If a TLS failure is required, a constantcan bereturned. Other return values will result in a TLS fatal error with.If there is an IDNA decoding error on the server name, the TLS connectionwill terminate with an fatal TLSalert message to the client.If an exception is raised from the servernamecallback function the TLSconnection will terminate with a fatal TLS alert message.This method will raise if the OpenSSL libraryhad OPENSSLNOTLSEXT defined when it was built. See also Vincent Bernat.

Wrapsocket ( sock, serverside=False, dohandshakeonconnect=True, suppressraggedeofs=True, serverhostname=None )Wrap an existing Python socket sock and return anobject. Sock must be a socket; other sockettypes are unsupported.The returned SSL socket is tied to the context, its settings andcertificates. The parameters serverside, dohandshakeonconnectand suppressraggedeofs have the same meaning as in the top-levelfunction.On client connections, the optional parameter serverhostname specifiesthe hostname of the service which we are connecting to. This allows asingle server to host multiple SSL-based services with distinct certificates,quite similarly to HTTP virtual hosts. Specifying serverhostname willraise a if serverside is true.