Misplaced Pages

#432567

58-501: A web server can handle a Hypertext Transfer Protocol (HTTP) request either by reading a file from its file system based on the URL path or by handling the request using logic that is specific to the type of resource. In cases where special logic is invoked, the query string will be available to that logic for use in its processing, along with the path component of the URL. A typical URL containing

116-478: A CGI script , the script may typically receive the query string as an environment variable named QUERY_STRING . A program receiving a query string can ignore part or all of it. If the requested URL corresponds to a file and not to a program, the whole query string is ignored. However, regardless of whether the query string is used or not, the whole URL including it is stored in the server log files . These facts allow query strings to be used to track users in

174-415: A URI fragment is a string of characters that refers to a resource that is subordinate to another, primary resource. The primary resource is identified by a Uniform Resource Identifier (URI), and the fragment identifier points to the subordinate resource. The fragment identifier introduced by a hash mark # is the optional last part of a URL for a document. It is typically used to identify

232-473: A web of trust , the 2013 mass surveillance disclosures drew attention to certificate authorities as a potential weak point allowing man-in-the-middle attacks . An important property in this context is forward secrecy , which ensures that encrypted communications recorded in the past cannot be retrieved and decrypted should long-term secret keys or passwords be compromised in the future. Not all web servers provide forward secrecy. For HTTPS to be effective,

290-526: A campaign by the Electronic Frontier Foundation with the support of web browser developers led to the protocol becoming more prevalent. HTTPS is now used more often by web users than the original, non-secure HTTP, primarily to protect page authenticity on all types of websites, secure accounts, and keep user communications, identity, and web browsing private. The Uniform Resource Identifier (URI) scheme HTTPS has identical usage syntax to

348-449: A manner similar to that provided by HTTP cookies . For this to work, every time the user downloads a page, a unique identifier must be chosen and added as a query string to the URLs of all links the page contains. As soon as the user follows one of these links, the corresponding URL is requested to the server. This way, the download of this page is linked with the previous one. For example, when

406-618: A number of types, including Extended Validation Certificates . Let's Encrypt , launched in April 2016, provides free and automated service that delivers basic SSL/TLS certificates to websites. According to the Electronic Frontier Foundation , Let's Encrypt will make switching from HTTP to HTTPS "as easy as issuing one command, or clicking one button." The majority of web hosts and cloud providers now leverage Let's Encrypt, providing free certificates to their customers. The system can also be used for client authentication in order to limit access to

464-549: A particular address and port combination. In the past, this meant that it was not feasible to use name-based virtual hosting with HTTPS. A solution called Server Name Indication (SNI) exists, which sends the hostname to the server before encrypting the connection, although many old browsers do not support this extension. Support for SNI is available since Firefox 2, Opera 8, Apple Safari 2.1, Google Chrome 6, and Internet Explorer 7 on Windows Vista . A sophisticated type of man-in-the-middle attack called SSL stripping

522-497: A portion of that document. The generic syntax is specified in RFC 3986 . The hash mark separator in URIs is not part of the fragment identifier. In URIs, a hash mark # introduces the optional fragment near the end of the URL. The generic RFC 3986 syntax for URIs also allows an optional query part introduced by a question mark ? . In URIs with a query and a fragment, the fragment follows

580-445: A query string is as follows: https://example.com/over/there?name=ferret When a server receives a request for such a page, it may run a program, passing the query string, which in this case is name=ferret , unchanged to the program. The question mark is used as a separator, and is not part of the query string. Web frameworks may provide methods for parsing multiple parameters in the query string, separated by some delimiter. In

638-568: A request body. HTTPS This is an accepted version of this page Hypertext Transfer Protocol Secure ( HTTPS ) is an extension of the Hypertext Transfer Protocol (HTTP). It uses encryption for secure communication over a computer network , and is widely used on the Internet . In HTTPS, the communication protocol is encrypted using Transport Layer Security (TLS) or, formerly, Secure Sockets Layer (SSL). The protocol

SECTION 10

#1733085917433

696-480: A secure channel over an insecure network. This ensures reasonable protection from eavesdroppers and man-in-the-middle attacks , provided that adequate cipher suites are used and that the server certificate is verified and trusted. Because HTTPS piggybacks HTTP entirely on top of TLS, the entirety of the underlying HTTP protocol can be encrypted. This includes the request's URL , query parameters, headers, and cookies (which often contain identifying information about

754-755: A single field (e.g. field1=value1&field1=value2&field2=value3 ). For each field of the form, the query string contains a pair field = value . Web forms may include fields that are not visible to the user; these fields are included in the query string when the form is submitted. This convention is a W3C recommendation. In the recommendations of 1999, W3C recommended that all web servers support semicolon separators in addition to ampersand separators to allow application/x-www-form-urlencoded query strings in URLs within HTML documents without having to entity escape ampersands. Since 2014, W3C recommends to use only ampersand as query separator. The form content

812-461: A site must be completely hosted over HTTPS. If some of the site's contents are loaded over HTTP (scripts or images, for example), or if only a certain page that contains sensitive information, such as a log-in page, is loaded over HTTPS while the rest of the site is loaded over plain HTTP, the user will be vulnerable to attacks and surveillance. Additionally, cookies on a site served through HTTPS must have

870-427: A subsection (or fragment ) of a document. In HTML forms, the character = is used to separate a name from a value. The URI generic syntax uses URL encoding to deal with this problem, while HTML forms make some additional substitutions rather than applying percent encoding for all such characters. SPACE is encoded as ' + ' or " %20 ". HTML 5 specifies the following transformation for submitting HTML forms with

928-402: A user is communicating with, along with the amount of data transferred and the duration of the communication, though not the content of the communication. Web browsers know how to trust HTTPS websites based on certificate authorities that come pre-installed in their software. Certificate authorities are in this way being trusted by web browser creators to provide valid certificates. Therefore,

986-712: A user should trust an HTTPS connection to a website if and only if all of the following are true: HTTPS is especially important over insecure networks and networks that may be subject to tampering. Insecure networks, such as public Wi-Fi access points, allow anyone on the same local network to packet-sniff and discover sensitive information not protected by HTTPS. Additionally, some free-to-use and paid WLAN networks have been observed tampering with webpages by engaging in packet injection in order to serve their own ads on other websites. This practice can be exploited maliciously in many ways, such as by injecting malware onto webpages and stealing users' private information. HTTPS

1044-764: A warning across the entire window. Newer browsers also prominently display the site's security information in the address bar . Extended validation certificates show the legal entity on the certificate information. Most browsers also display a warning to the user when visiting a site that contains a mixture of encrypted and unencrypted content. Additionally, many web filters return a security warning when visiting prohibited websites. The Electronic Frontier Foundation , opining that "In an ideal world, every web request could be defaulted to HTTPS", has provided an add-on called HTTPS Everywhere for Mozilla Firefox , Google Chrome , Chromium , and Android , which enables HTTPS by default for hundreds of frequently used websites. Forcing

1102-470: A web browser to load only HTTPS content has been supported in Firefox starting in version 83. Starting in version 94, Google Chrome is able to "always use secure connections" if toggled in the browser's settings. The security of HTTPS is that of the underlying TLS, which typically uses long-term public and private keys to generate a short-term session key , which is then used to encrypt the data flow between

1160-439: A web page containing the following is requested: a unique string, such as e0a72cb2a2c7 is chosen, and the page is modified as follows: The addition of the query string does not change the way the page is shown to the user. When the user follows, for example, the first link, the browser requests the page foo.html?e0a72cb2a2c7 to the server, which ignores what follows ? and sends the page foo.html as expected, adding

1218-604: A web server to accept HTTPS connections, the administrator must create a public key certificate for the web server. This certificate must be signed by a trusted certificate authority for the web browser to accept it without warning. The authority certifies that the certificate holder is the operator of the web server that presents it. Web browsers are generally distributed with a list of signing certificates of major certificate authorities so that they can verify certificates signed by them. A number of commercial certificate authorities exist, offering paid-for SSL/TLS certificates of

SECTION 20

#1733085917433

1276-422: A web server to authorized users. To do this, the site administrator typically creates a certificate for each user, which the user loads into their browser. Normally, the certificate contains the name and e-mail address of the authorized user and is automatically checked by the server on each connection to verify the user's identity, potentially without even requiring a password. An important property in this context

1334-641: A web server, the agent sends the URI to the server, but does not send the fragment. Instead, the agent waits for the server to send the resource, and then the agent processes the resource according to the document type and fragment value. In an HTML web page, the agent will look for an anchor identified with an HTML tag that includes an id= or name= attribute equal to the fragment identifier. Several proposals have been made for fragment identifiers for use with plain text documents (which cannot store anchor metadata), or to refer to locations within HTML documents in which

1392-1055: Is perfect forward secrecy (PFS). Possessing one of the long-term asymmetric secret keys used to establish an HTTPS session should not make it easier to derive the short-term session key to then decrypt the conversation, even at a later time. Diffie–Hellman key exchange (DHE) and Elliptic-curve Diffie–Hellman key exchange (ECDHE) are in 2013 the only schemes known to have that property. In 2013, only 30% of Firefox, Opera, and Chromium Browser sessions used it, and nearly 0% of Apple's Safari and Microsoft Internet Explorer sessions. TLS 1.3, published in August 2018, dropped support for ciphers without forward secrecy. As of February 2019 , 96.6% of web servers surveyed support some form of forward secrecy, and 52.1% will use forward secrecy with most browsers. As of July 2023 , 99.6% of web servers surveyed support some form of forward secrecy, and 75.2% will use forward secrecy with most browsers. A certificate may be revoked before it expires, for example because

1450-639: Is also important for connections over the Tor network , as malicious Tor nodes could otherwise damage or alter the contents passing through them in an insecure fashion and inject malware into the connection. This is one reason why the Electronic Frontier Foundation and the Tor Project started the development of HTTPS Everywhere , which is included in Tor Browser. As more information is revealed about global mass surveillance and criminals stealing personal information,

1508-537: Is designed to withstand such attacks and is considered secure against them (with the exception of HTTPS implementations that use deprecated versions of SSL). HTTP operates at the highest layer of the TCP/IP model —the application layer ; as does the TLS security protocol (operating as a lower sublayer of the same layer), which encrypts an HTTP message prior to transmission and decrypts a message upon arrival. Strictly speaking, HTTPS

1566-476: Is not a separate protocol, but refers to the use of ordinary HTTP over an encrypted SSL/TLS connection. HTTPS encrypts all message contents, including the HTTP headers and the request/response data. With the exception of the possible CCA cryptographic attack described in the limitations section below, an attacker should at most be able to discover that a connection is taking place between two parties, along with their domain names and IP addresses. To prepare

1624-465: Is only encoded in the URL's query string when the form submission method is GET . The same encoding is used by default when the submission method is POST , but the result is submitted as the HTTP request body rather than being included in a modified URL. Before forms were added to HTML, browsers rendered the – <isindex> element as a single-line text-input control. The text entered into this control

1682-456: Is only performed by the server. The mutual version requires the user to install a personal client certificate in the web browser for user authentication. In either case, the level of protection depends on the correctness of the implementation of the software and the cryptographic algorithms in use. SSL/TLS does not prevent the indexing of the site by a web crawler , and in some cases the URI of

1740-483: Is recommended to use HTTP Strict Transport Security (HSTS) with HTTPS to protect users from man-in-the-middle attacks, especially SSL stripping . HTTPS should not be confused with the seldom-used Secure HTTP (S-HTTP) specified in RFC 2660. As of April 2018 , 33.2% of Alexa top 1,000,000 websites use HTTPS as default and 70% of page loads (measured by Firefox Telemetry) use HTTPS. As of December 2022 , 58.4% of

1798-401: Is therefore also referred to as HTTP over TLS , or HTTP over SSL . The principal motivations for HTTPS are authentication of the accessed website and protection of the privacy and integrity of the exchanged data while it is in transit. It protects against man-in-the-middle attacks , and the bidirectional block cipher encryption of communications between a client and server protects

Query string - Misplaced Pages Continue

1856-432: The <isindex> element is deprecated and most browsers no longer support or render it, there are still some vestiges of indexed search in existence. For example, this is the source of the special handling of plus sign , ' + ' within browser URL percent encoding (which today, with the deprecation of indexed search, is all but redundant with %20 ). Also some web servers supporting CGI (e.g., Apache ) will process

1914-402: The HTTP specification: Various ad hoc limitations on request-line length are found in practice. It is RECOMMENDED that all HTTP senders and recipients support, at a minimum, request-line lengths of 8000 octets. If the URL is too long, the web server fails with the 414 Request-URI Too Long HTTP status code. The common workaround for these problems is to use POST instead of GET and store

1972-569: The secure attribute enabled. On a site that has sensitive information on it, the user and the session will get exposed every time that site is accessed with HTTP instead of HTTPS. HTTPS URLs begin with "https://" and use port 443 by default, whereas, HTTP URLs begin with "http://" and use port 80 by default. HTTP is not encrypted and thus is vulnerable to man-in-the-middle and eavesdropping attacks , which can let attackers gain access to website accounts and sensitive information, and modify webpages to inject malware or advertisements. HTTPS

2030-417: The "GET" method to a web server. The following is a brief summary of the algorithm: The octet corresponding to the tilde (" ~ ") is permitted in query strings by RFC3986 but required to be percent-encoded in HTML forms to " %7E ". The encoding of SPACE as ' + ' and the selection of "as-is" characters distinguishes this encoding from RFC 3986. If a form is embedded in an HTML page as follows: and

2088-489: The HTTP scheme. However, HTTPS signals the browser to use an added encryption layer of SSL/TLS to protect the traffic. SSL/TLS is especially suited for HTTP, since it can provide some protection even if only one side of the communication is authenticated . This is the case with HTTP transactions over the Internet, where typically only the server is authenticated (by the client examining the server's certificate ). HTTPS creates

2146-463: The Internet's 135,422 most popular websites have a secure implementation of HTTPS, However, despite TLS 1.3's release in 2018, adoption has been slow, with many still remaining on the older TLS 1.2 protocol. Most browsers display a warning if they receive an invalid certificate. Older browsers, when connecting to a site with an invalid certificate, would present the user with a dialog box asking whether they wanted to continue. Newer browsers display

2204-639: The authority responds, telling the browser whether the certificate is still valid or not. The CA may also issue a CRL to tell people that these certificates are revoked. CRLs are no longer required by the CA/Browser forum, nevertheless, they are still widely used by the CAs. Most revocation statuses on the Internet disappear soon after the expiration of the certificates. SSL (Secure Sockets Layer) and TLS (Transport Layer Security) encryption can be configured in two modes: simple and mutual . In simple mode, authentication

2262-412: The client and the server. X.509 certificates are used to authenticate the server (and sometimes the client as well). As a consequence, certificate authorities and public key certificates are necessary to verify the relation between the certificate and its owner, as well as to generate, sign, and administer the validity of certificates. While this can be more beneficial than verifying the identities via

2320-444: The client. This prompted the development of a countermeasure in HTTP called HTTP Strict Transport Security . HTTPS has been shown to be vulnerable to a range of traffic analysis attacks. Traffic analysis attacks are a type of side-channel attack that relies on variations in the timing and size of traffic in order to infer properties about the encrypted traffic itself. Traffic analysis is possible because SSL/TLS encryption changes

2378-469: The communications against eavesdropping and tampering . The authentication aspect of HTTPS requires a trusted third party to sign server-side digital certificates . This was historically an expensive operation, which meant fully authenticated HTTPS connections were usually found only on secured payment transaction services and other secured corporate information systems on the World Wide Web . In 2016,

Query string - Misplaced Pages Continue

2436-472: The contents of traffic, but has minimal impact on the size and timing of traffic. In May 2010, a research paper by researchers from Microsoft Research and Indiana University discovered that detailed sensitive user data can be inferred from side channels such as packet sizes. The researchers found that, despite HTTPS protection in several high-profile, top-of-the-line web applications in healthcare, taxation, investment, and web search, an eavesdropper could infer

2494-477: The encrypted resource can be inferred by knowing only the intercepted request/response size. This allows an attacker to have access to the plaintext (the publicly available static content), and the encrypted text (the encrypted version of the static content), permitting a cryptographic attack . Because TLS operates at a protocol level below that of HTTP and has no knowledge of the higher-level protocols, TLS servers can only strictly present one certificate for

2552-413: The example URL below, multiple query parameters are separated by the ampersand , " & ": https://example.com/path/to/page?name=ferret&color=purple The exact structure of the query string is not standardized. Methods used to parse the query string may differ between websites. A link in a web page may have a URL that contains a query string. HTML defines three ways a user agent can generate

2610-575: The illnesses/medications/surgeries of the user, his/her family income, and investment secrets. The fact that most modern websites, including Google, Yahoo!, and Amazon, use HTTPS causes problems for many users trying to access public Wi-Fi hot spots, because a captive portal Wi-Fi hot spot login page fails to load if the user tries to open an HTTPS resource. Several websites, such as NeverSSL, guarantee that they will always remain accessible by HTTP. Netscape Communications created HTTPS in 1994 for its Netscape Navigator web browser. Originally, HTTPS

2668-468: The parameters in the request body. The length limits on request bodies are typically much higher than those on URL length. For example, the limit on POST size, by default, is 2 MB on IIS 4.0 and 128 KB on IIS 5.0. The limit is configurable on Apache2 using the LimitRequestBody directive, which specifies the number of bytes from 0 (meaning unlimited) to 2147483647 (2 GB) that are allowed in

2726-409: The query string into command line arguments if it does not contain an equals sign , ' = ' (as per section 4.4 of CGI 1.1). Some CGI scripts still depend on and use this historic behavior for URLs embedded in HTML. Some characters cannot be part of a URL (for example, the space) and some other characters have a special meaning in a URL: for example, the character # can be used to further specify

2784-401: The query string to its links as well. This way, any subsequent page request from this user will carry the same query string e0a72cb2a2c7 , making it possible to establish that all these pages have been viewed by the same user. Query strings are often used in association with web beacons . The main differences between query strings used for tracking and HTTP cookies are that: According to

2842-444: The query string: One of the original uses was to contain the content of an HTML form , also known as web form. In particular, when a form containing the fields field1 , field2 , field3 is submitted, the content of the fields is encoded as a query string as follows: field1=value1&field2=value2&field3=value3... While there is no definitive standard, most web frameworks allow multiple values to be associated with

2900-582: The query. Query parts depend on the URI scheme and are evaluated by the server—e.g., http: supports queries unlike ftp: . Fragments depend on the document MIME type and are evaluated by the client ( web browser ). Clients are not supposed to send URI fragments to servers when they retrieve a document. A URI ending with # is permitted by the generic syntax and is a kind of empty fragment. In MIME document types such as text/html or any XML type, empty identifiers to match this syntactically legal construct are not permitted. Web browsers typically display

2958-477: The secrecy of the private key has been compromised. Newer versions of popular browsers such as Firefox , Opera , and Internet Explorer on Windows Vista implement the Online Certificate Status Protocol (OCSP) to verify that this is not the case. The browser sends the certificate's serial number to the certificate authority or its delegate via OCSP (Online Certificate Status Protocol) and

SECTION 50

#1733085917433

3016-494: The top of the document for an empty fragment. The fragment identifier functions differently to the rest of the URI: its processing is exclusively client-sided with no participation from the web server , though the server typically helps to determine the MIME type, and the MIME type determines the processing of fragments. When an agent (such as a web browser) requests a web resource from

3074-520: The use of HTTPS security on all websites is becoming increasingly important regardless of the type of Internet connection being used. Even though metadata about individual pages that a user visits might not be considered sensitive, when aggregated it can reveal a lot about the user and compromise the user's privacy. Deploying HTTPS also allows the use of HTTP/2 and HTTP/3 (and their predecessors SPDY and QUIC ), which are new HTTP versions designed to reduce page load times, size, and latency. It

3132-412: The user inserts the strings "this is a field" and "was it clear (already)?" in the two text fields and presses the submit button, the program test.cgi (the program specified by the action attribute of the form element in the above example) will receive the following query string: first=this+is+a+field&second=was+it+clear+%28already%29%3F . If the form is processed on the server by

3190-490: The user). However, because website addresses and port numbers are necessarily part of the underlying TCP/IP protocols, HTTPS cannot protect their disclosure. In practice this means that even on a correctly configured web server, eavesdroppers can infer the IP address and port number of the web server, and sometimes even the domain name (e.g. www.example.org, but not the rest of the URL) that

3248-456: Was presented at the 2009 Blackhat Conference . This type of attack defeats the security provided by HTTPS by changing the https: link into an http: link, taking advantage of the fact that few Internet users actually type "https" into their browser interface: they get to a secure site by clicking on a link, and thus are fooled into thinking that they are using HTTPS when in fact they are using HTTP. The attacker then communicates in clear with

3306-427: Was sent to the server as a query string addition to a GET request for the base URL or another URL specified by the action attribute. This was intended to allow web servers to use the provided text as query criteria so they could return a list of matching pages. When the text input into the indexed search control is submitted, it is encoded as a query string as follows: argument1+argument2+argument3... Though

3364-571: Was used with the SSL protocol. As SSL evolved into Transport Layer Security (TLS), HTTPS was formally specified by RFC 2818 in May 2000. Google announced in February 2018 that its Chrome browser would mark HTTP sites as "Not Secure" after July 2018. This move was to encourage website owners to implement HTTPS, as an effort to make the World Wide Web more secure. Fragment identifier In computer hypertext ,

#432567