Handles contacting an HTTP server and retrieving a document. More...

Inheritance diagram for HTTPClient:
ReferenceCount MemoryBase

List of all members.

Public Types

enum  VerifySSL { VSNoVerify = 0, VSNoDateCheck = 1, VSNormal = 2 }

Public Member Functions

 HTTPClient ()
 HTTPClient (HTTPClient const copy)
 addDirectHost (string hostname)
 Adds the indicated name to the set of hostnames that are connected to directly, without using a proxy.
bool addPreapprovedServerCertificateFilename (URLSpec const url, Filename const filename)
 Adds the certificate defined in the indicated PEM filename as a "pre-approved" certificate for the indicated server, defined by the hostname and port (only) from the given URL.
bool addPreapprovedServerCertificateName (URLSpec const url, string name)
 Adds the certificate *name* only, as a "pre-approved" certificate name for the indicated server, defined by the hostname and port (only) from the given URL.
bool addPreapprovedServerCertificatePem (URLSpec const url, string pem)
 Adds the certificate defined in the indicated data string, formatted as a PEM block, as a "pre-approved" certificate for the indicated server, defined by the hostname and port (only) from the given URL.
 addProxy (string scheme, URLSpec const proxy)
 Adds the indicated proxy host as a proxy for communications on the given scheme.
 clearAllCookies ()
 Removes the all stored cookies from the client.
 clearAllPreapprovedServerCertificates ()
 Removes all preapproved server certificates for all servers.
bool clearCookie (HTTPCookie const cookie)
 Removes the cookie with the matching domain/path/name from the client's list of cookies.
 clearDirectHost ()
 Resets the set of direct hosts to empty.
 clearPreapprovedServerCertificates (URLSpec const url)
 Removes all preapproved server certificates for the indicated server and port.
 clearProxy ()
 Resets the proxy spec to empty.
 copyCookiesFrom (HTTPClient const other)
 Copies all the cookies from the indicated HTTPClient into this one.
string getCipherList ()
 Returns the set of ciphers as set by set_cipher_list().
HTTPCookie getCookie (HTTPCookie const cookie)
 Looks up and returns the cookie in the client matching the given cookie's domain/path/name.
string getDirectHostSpec ()
 Returns the set of hosts that should be connected to directly, without using a proxy, as a semicolon-separated list of hostnames that may contain wildcard characters ("*").
HTTPChannel getDocument (URLSpec const url)
 Opens the named document for reading.
HTTPChannel getHeader (URLSpec const url)
 Like get_document(), except only the header associated with the document is retrieved.
HTTPVersion getHttpVersion ()
 Returns the client's current setting for HTTP version.
string getHttpVersionString ()
 Returns the current HTTP version setting as a string, e.g.
string getProxiesForUrl (URLSpec const url)
 Returns a semicolon-delimited list of proxies, in the order in which they should be tried, that are appropriate for the indicated URL.
 getProxiesForUrl (URLSpec const url, vectorURLSpec proxies)
 Fills up the indicated vector with the list of URLSpec objects, in the order in which they should be tried, that are appropriate proxies to try for the indicated URL.
string getProxySpec ()
 Returns the complete set of proxies to use for all schemes.
bool getTryAllDirect ()
 Returns whether a failed connection through a proxy will be followed up by a direct connection attempt, false otherwise.
string getUsername (string server, string realm)
 Returns the username:password string set for this server/realm pair, or empty string if nothing has been set.
VerifySSL getVerifySsl ()
 Returns whether the client will insist on verifying the identity of the servers it connects to via SSL (that is, https).
bool hasCookie (HTTPCookie const cookie)
 Returns true if there is a cookie in the client matching the given cookie's domain/path/name, false otherwise.
bool loadCertificates (Filename const filename)
 Reads the certificate(s) (delimited by -----BEGIN CERTIFICATE----- and -----END CERTIFICATE-----) from the indicated file and makes them known as trusted public keys for validating future connections.
bool loadClientCertificate ()
 Attempts to load the certificate named by set_client_certificate_filename() immediately, and returns true if successful, false otherwise.
HTTPChannel makeChannel (bool persistent_connection)
 Returns a new HTTPChannel object that may be used for reading multiple documents using the same connection, for greater network efficiency than calling HTTPClient.get_document() repeatedly (which would force a new connection for each document).
HTTPClient operator= (HTTPClient const copy)
HTTPChannel postForm (URLSpec const url, string body)
 Posts form data to a particular URL and retrieves the response.
 sendCookies (ostream out, URLSpec const url)
 Writes to the indicated ostream a "Cookie" header line for sending the cookies appropriate to the indicated URL along with an HTTP request.
 setCipherList (string cipher_list)
 Specifies the set of ciphers that are to be made available for SSL connections.
 setClientCertificateFilename (Filename const filename)
 Sets the filename of the pem-formatted file that will be read for the client public and private keys if an SSL server requests a certificate.
 setClientCertificatePassphrase (string passphrase)
 Sets the passphrase used to decrypt the private key in the certificate named by set_client_certificate_filename() or set_client_certificate_pem().
 setClientCertificatePem (string pem)
 Sets the pem-formatted contents of the certificate that will be parsed for the client public and private keys if an SSL server requests a certificate.
 setCookie (HTTPCookie const cookie)
 Stores the indicated cookie in the client's list of cookies, as if it had been received from a server.
 setDirectHostSpec (string direct_host_spec)
 Specifies the set of hosts that should be connected to directly, without using a proxy.
 setHttpVersion (HTTPVersion version)
 Specifies the version of HTTP that the client uses to identify itself to the server.
 setProxySpec (string proxy_spec)
 Specifies the complete set of proxies to use for all schemes.
 setTryAllDirect (bool try_all_direct)
 If this is set true, then after a connection attempt through a proxy fails, we always try a direct connection, regardless of whether the host is listed on the direct_host_spec list.
 setUsername (string server, string realm, string username)
 Specifies the username:password string corresponding to a particular server and/or realm, when demanded by the server.
 setVerifySsl (VerifySSL verify_ssl)
 Specifies whether the client will insist on verifying the identity of the servers it connects to via SSL (that is, https).
 writeCookies (ostream out)
 Outputs the complete list of cookies stored on the client, for all domains, including the expired cookies (which will normally not be sent back to a host).

Static Public Member Functions

static string base64Decode (string s)
 Implements HTTPAuthorization.base64_decode().
static string base64Encode (string s)
 Implements HTTPAuthorization.base64_encode().
static HTTPClient getGlobalPtr ()
 Returns the default global HTTPClient.
static initRandomSeed ()
 This may be called once, presumably at the beginning of an application, to initialize OpenSSL's random seed.
static HTTPVersion parseHttpVersionString (string version)
 Matches the string representing a particular HTTP version against any of the known versions and returns the appropriate enumerated value, or HV_other if the version is unknown.

Detailed Description

Handles contacting an HTTP server and retrieving a document.

Each HTTPClient object represents a separate context, and stores its own list of cookies, passwords, and certificates; however, a given HTTPClient is capable of making multiple simultaneous requests to the same or different servers.

It is up to the programmer whether one HTTPClient should be used to retrieve all documents, or a separate one should be created each time. There is a default, global HTTPClient available in HTTPClient.get_global_ptr().


Member Enumeration Documentation

enum VerifySSL
Enumerator:
VSNoVerify 
VSNoDateCheck 
VSNormal 

Constructor & Destructor Documentation

HTTPClient ( HTTPClient const  copy)

Member Function Documentation

addDirectHost ( string  hostname)

Adds the indicated name to the set of hostnames that are connected to directly, without using a proxy.

This name may be either a DNS name or an IP address, and it may include the * as a wildcard character.

bool addPreapprovedServerCertificateFilename ( URLSpec const  url,
Filename const  filename 
)

Adds the certificate defined in the indicated PEM filename as a "pre-approved" certificate for the indicated server, defined by the hostname and port (only) from the given URL.

If the server offers this particular certificate on a secure connection, it will be accepted without question. This is particularly useful for communicating with a server using a known self-signed certificate.

See also the similar add_preapproved_server_certificate_pem(), and the weaker add_preapproved_server_certificate_name().

bool addPreapprovedServerCertificateName ( URLSpec const  url,
string  name 
)

Adds the certificate *name* only, as a "pre-approved" certificate name for the indicated server, defined by the hostname and port (only) from the given URL.

This is a weaker function than add_preapproved_server_certificate_filename(). This checks only the subject name of the certificate, without checking for a particular certificate by key. This means that a variety of server certificates may match the indicated name.

Because this is a weaker verification, it only applies to server certificates that are signed by a recognized certificate authority. Thus, it cannot be used to pre-approve self-signed certificates, but it can be used to accept a server certificate offered by a different hostname than the one in the cert itself.

The certificate name should be formatted in the form /type0=value0/type1=value1/type2=...

bool addPreapprovedServerCertificatePem ( URLSpec const  url,
string  pem 
)

Adds the certificate defined in the indicated data string, formatted as a PEM block, as a "pre-approved" certificate for the indicated server, defined by the hostname and port (only) from the given URL.

If the server offers this particular certificate on a secure connection, it will be accepted without question. This is particularly useful for communicating with a server using a known self-signed certificate.

See also the similar add_preapproved_server_certificate_filename(), and the weaker add_preapproved_server_certificate_name().

addProxy ( string  scheme,
URLSpec const  proxy 
)

Adds the indicated proxy host as a proxy for communications on the given scheme.

Usually the scheme is "http" or "https". It may be the empty string to indicate a general proxy. The proxy string may be the empty URL to indicate a direct connection.

static string base64Decode ( string  s) [static]

Implements HTTPAuthorization.base64_decode().

This is provided here just as a convenient place to publish it for access by the scripting language; C++ code should probably use HTTPAuthorization directly.

static string base64Encode ( string  s) [static]

Implements HTTPAuthorization.base64_encode().

This is provided here just as a convenient place to publish it for access by the scripting language; C++ code should probably use HTTPAuthorization directly.

clearAllCookies ( )

Removes the all stored cookies from the client.

clearAllPreapprovedServerCertificates ( )

Removes all preapproved server certificates for all servers.

bool clearCookie ( HTTPCookie const  cookie)

Removes the cookie with the matching domain/path/name from the client's list of cookies.

Returns true if it was removed, false if the cookie was not matched.

clearDirectHost ( )

Resets the set of direct hosts to empty.

Subsequent calls to add_direct_host() may be made to build up the list of hosts that do not require a proxy connection.

clearPreapprovedServerCertificates ( URLSpec const  url)

Removes all preapproved server certificates for the indicated server and port.

clearProxy ( )

Resets the proxy spec to empty.

Subsequent calls to add_proxy() may be made to build up the set of proxy servers.

copyCookiesFrom ( HTTPClient const  other)

Copies all the cookies from the indicated HTTPClient into this one.

Existing cookies in this client are not affected, unless they are shadowed by the new cookies.

string getCipherList ( )

Returns the set of ciphers as set by set_cipher_list().

See set_cipher_list().

HTTPCookie getCookie ( HTTPCookie const  cookie)

Looks up and returns the cookie in the client matching the given cookie's domain/path/name.

If there is no matching cookie, returns an empty cookie.

string getDirectHostSpec ( )

Returns the set of hosts that should be connected to directly, without using a proxy, as a semicolon-separated list of hostnames that may contain wildcard characters ("*").

HTTPChannel getDocument ( URLSpec const  url)

Opens the named document for reading.

Returns a new HTTPChannel object whether the document is successfully read or not; you can test is_valid() and get_return_code() to determine whether the document was retrieved.

static HTTPClient getGlobalPtr ( ) [static]

Returns the default global HTTPClient.

HTTPChannel getHeader ( URLSpec const  url)

Like get_document(), except only the header associated with the document is retrieved.

This may be used to test for existence of the document; it might also return the size of the document (if the server gives us this information).

HTTPVersion getHttpVersion ( )

Returns the client's current setting for HTTP version.

See set_http_version().

string getHttpVersionString ( )

Returns the current HTTP version setting as a string, e.g.

"HTTP/1.0" or "HTTP/1.1".

string getProxiesForUrl ( URLSpec const  url)

Returns a semicolon-delimited list of proxies, in the order in which they should be tried, that are appropriate for the indicated URL.

The keyword DIRECT indicates a direct connection should be tried.

getProxiesForUrl ( URLSpec const  url,
vectorURLSpec  proxies 
)

Fills up the indicated vector with the list of URLSpec objects, in the order in which they should be tried, that are appropriate proxies to try for the indicated URL.

The empty URL is returned for a direct connection.

It is the user's responsibility to empty this vector before calling this method; otherwise, the proxy URL's will simply be appended to the existing list.

string getProxySpec ( )

Returns the complete set of proxies to use for all schemes.

This is a string of the form specified by set_proxy_spec(), above. Note that the string returned by this function may not be exactly the same as the string passed into set_proxy_spec(), since the string is regenerated from the internal storage structures and may therefore be reordered.

bool getTryAllDirect ( )

Returns whether a failed connection through a proxy will be followed up by a direct connection attempt, false otherwise.

string getUsername ( string  server,
string  realm 
)

Returns the username:password string set for this server/realm pair, or empty string if nothing has been set.

See set_username().

VerifySSL getVerifySsl ( )

Returns whether the client will insist on verifying the identity of the servers it connects to via SSL (that is, https).

See set_verify_ssl().

bool hasCookie ( HTTPCookie const  cookie)

Returns true if there is a cookie in the client matching the given cookie's domain/path/name, false otherwise.

static initRandomSeed ( ) [static]

This may be called once, presumably at the beginning of an application, to initialize OpenSSL's random seed.

On Windows, it is particularly important to call this at startup if you are going to be performing any https operations or otherwise use encryption, since the Windows algorithm for getting a random seed takes 2-3 seconds at startup, but can take 30 seconds or more after you have opened a 3-D graphics window and started rendering.

There is no harm in calling this method multiple times, or in not calling it at all.

bool loadCertificates ( Filename const  filename)

Reads the certificate(s) (delimited by -----BEGIN CERTIFICATE----- and -----END CERTIFICATE-----) from the indicated file and makes them known as trusted public keys for validating future connections.

Returns true on success, false otherwise.

bool loadClientCertificate ( )

Attempts to load the certificate named by set_client_certificate_filename() immediately, and returns true if successful, false otherwise.

Normally this need not be explicitly called, since it will be called automatically if the server requests a certificate, but it may be useful to determine ahead of time if the certificate can be loaded correctly.

HTTPChannel makeChannel ( bool  persistent_connection)

Returns a new HTTPChannel object that may be used for reading multiple documents using the same connection, for greater network efficiency than calling HTTPClient.get_document() repeatedly (which would force a new connection for each document).

Also, HTTPChannel has some additional, less common interface methods than the basic interface methods that exist on HTTPClient; if you wish to call any of these methods you must first obtain an HTTPChannel.

Pass true for persistent_connection to gain this network efficiency. If, on the other hand, your intention is to use the channel to retrieve only one document, then pass false to inform the server that we will be dropping the connection after the first document.

HTTPClient operator= ( HTTPClient const  copy)
static HTTPVersion parseHttpVersionString ( string  version) [static]

Matches the string representing a particular HTTP version against any of the known versions and returns the appropriate enumerated value, or HV_other if the version is unknown.

HTTPChannel postForm ( URLSpec const  url,
string  body 
)

Posts form data to a particular URL and retrieves the response.

Returns a new HTTPChannel object whether the document is successfully read or not; you can test is_valid() and get_return_code() to determine whether the document was retrieved.

sendCookies ( ostream  out,
URLSpec const  url 
)

Writes to the indicated ostream a "Cookie" header line for sending the cookies appropriate to the indicated URL along with an HTTP request.

This also removes expired cookies.

setCipherList ( string  cipher_list)

Specifies the set of ciphers that are to be made available for SSL connections.

This is a string as described in the ciphers(1) man page of the OpenSSL documentation (or see http://www.openssl.org/docs/apps/ciphers.html ). If this is not specified, the default is provided by the Config file. You may also specify "DEFAULT" to use the built-in OpenSSL default value.

setClientCertificateFilename ( Filename const  filename)

Sets the filename of the pem-formatted file that will be read for the client public and private keys if an SSL server requests a certificate.

Either this or set_client_certificate_pem() may be used to specify a client certificate.

setClientCertificatePassphrase ( string  passphrase)

Sets the passphrase used to decrypt the private key in the certificate named by set_client_certificate_filename() or set_client_certificate_pem().

setClientCertificatePem ( string  pem)

Sets the pem-formatted contents of the certificate that will be parsed for the client public and private keys if an SSL server requests a certificate.

Either this or set_client_certificate_filename() may be used to specify a client certificate.

setCookie ( HTTPCookie const  cookie)

Stores the indicated cookie in the client's list of cookies, as if it had been received from a server.

setDirectHostSpec ( string  direct_host_spec)

Specifies the set of hosts that should be connected to directly, without using a proxy.

This is a semicolon-separated list of hostnames that may contain wildcard characters ("*").

setHttpVersion ( HTTPVersion  version)

Specifies the version of HTTP that the client uses to identify itself to the server.

The default is HV_11, or HTTP 1.0; you can set this to HV_10 (HTTP 1.0) to request the server use the older interface.

setProxySpec ( string  proxy_spec)

Specifies the complete set of proxies to use for all schemes.

This is either a semicolon-delimited set of hostname:ports, or a semicolon-delimited set of pairs of the form "scheme=hostname:port", or a combination. Use the keyword DIRECT, or an empty string, to represent a direct connection. A particular scheme and/or proxy host may be listed more than once. This is a convenience function that can be used in place of explicit calls to add_proxy() for each scheme/proxy pair.

setTryAllDirect ( bool  try_all_direct)

If this is set true, then after a connection attempt through a proxy fails, we always try a direct connection, regardless of whether the host is listed on the direct_host_spec list.

If this is false, a direct attempt is not made when we have a proxy in effect, even if the proxy fails.

setUsername ( string  server,
string  realm,
string  username 
)

Specifies the username:password string corresponding to a particular server and/or realm, when demanded by the server.

Either or both of the server or realm may be empty; if so, they match anything. Also, the server may be set to the special string "*proxy", which will match any proxy server.

If the username is set to the empty string, this clears the password for the particular server/realm pair.

setVerifySsl ( VerifySSL  verify_ssl)

Specifies whether the client will insist on verifying the identity of the servers it connects to via SSL (that is, https).

The parameter value is an enumerated type which indicates the level of security to which the client will insist upon.

writeCookies ( ostream  out)

Outputs the complete list of cookies stored on the client, for all domains, including the expired cookies (which will normally not be sent back to a host).