Please review these documents carefully, as they describe your rights and restrictions with respect to this document. For example, the string A1 illustrated above must be. To clarify the purpose of the existing "HTTP Digest Algorithm Values" registry and to avoid confusion between the two registries, IANA has added the following description to the existing "HTTP Digest Algorithm Values" registry: This specification updates the existing entry of the Digest scheme in the "Hypertext Transfer Protocol (HTTP) Authentication Scheme Registry" and adds a new reference to this specification. A nonce might, for example, be constructed as the Base64 encoding of. Digest Authentication requires that the authenticating agent (usually the server) store some data derived from the user's name and password in a "password file" associated with a given realm. Why is proving something is NP-complete useful, and where can I use it? If the qop parameter's value is "auth" or is unspecified, then A2 is: If the qop value is "auth-int", then A2 is: To protect the transport of the username from the client to the server, the server SHOULD set the userhash parameter with the value of "true" in the WWW-Authentication header field. In other words, algorithm agility does not make this usage any more secure. Implementers should be aware of how authenticated transactions need to interact with shared caches (see [RFC7234]). Or, a hostile proxy might spoof the client into making a request the attacker wanted rather than one the client wanted. The values of the opaque and algorithm fields must be those supplied in the WWW-Authenticate response header field for the entity being requested. The following definitions show how the value is computed. The server-created "nonce" value is implementation dependent, but if it contains a digest of the client IP, a timestamp, the resource ETag, and a private server key (as recommended above), then a replay attack is not simple. Make a wide rectangle out of T-Pipes without loops. However, that would break because requests from a single user often go through different proxies. Both client and server know that the username for this document is "Mufasa" and the password is "Circle of Life" (with one space between each of the three words). The authors would like to thank Stephen Farrell, Yoav Nir, Phillip Hallam-Baker, Manu Sporny, Paul Hoffman, Yaron Sheffer, Sean Turner, Geoff Baskwill, Eric Cooper, Bjoern Hoehrmann, Martin Durst, Peter Saint-Andre, Michael Sweet, Daniel Stenberg, Brett Tate, Paul Leach, Ilari Liusvaara, Gary Mort, Alexey Melnikov, Benjamin Kaduk, Kathleen Moriarty, Francis Dupont, Hilarie Orman, and Ben Campbell for their careful review and comments. The details of the challenge-response authentication mechanism are specified in the "Hypertext Transfer Protocol (HTTP/1.1): Authentication" [RFC7235]. Nevertheless, many functions remain for which Digest Authentication is both useful and appropriate. The countermeasure against this attack is for clients to use the cnonce parameter; this allows the client to vary the input to the hash in a way not chosen by the attacker. The Digest scheme is based on a simple challenge-response paradigm. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Even if most passwords are not in the dictionary, some might be. Each sequence of four bits is represented by its familiar hexadecimal notation from the characters 0123456789abcdef; that is, binary 0000 is represented by the character '0', 0001 by '1' and so on up to the representation of 1111 as 'f'. where timestamp is a server-generated time, which preferably includes micro- or nanoseconds, or other non-repeating values; ETag is the value of the HTTP ETag header field associated with the requested entity; and secret-data is data known only to the server. HTTP Digest Access Authentication @Andy what do you mean by "decode the credentials"? A good Digest implementation can do this in various ways. An implementation must give special attention to the possibility of replay attacks with POST and PUT requests. The client/proxy MUST then reissue the request with a Proxy-Authorization header field, with parameters as specified for the Authorization header field in Section 3.4 above. As soon as the client types in the correct username:password,as requested by the Web-server, the Web-Server checks in the Database if the credentials are correct and gives the access to the resource . A client is encouraged to fail gracefully if the server specifies only authentication schemes it cannot handle. The authentication session lasts until the client receives another WWW-Authenticate challenge from any server in the protection space. However, it should be noted that the method chosen for generating and checking the nonce also has performance and resource implications. @Gili You are confusing yourself with encryption and authentication. This can be used to confirm the identity of a user before sending sensitive information, such as online banking transaction history. Did Dick Cheney run a death squad that killed Benazir Bhutto? Introduces the username hashing capability and the parameter associated with that, mainly for privacy reasons. This specification creates a new IANA registry named "Hash Algorithms for HTTP Digest Authentication" under the existing "Hypertext Transfer Protocol (HTTP) Digest Algorithm Values" category. Found footage movie where teens get superpowers after getting struck by lightning? 2022 Moderator Election Q&A Question Collection, What is the "realm" in basic authentication, How to send request with Digest authentication in angular ionic, Restricting access to api from another application ruby. The server, A string indicating an algorithm used to produce the digest and an unkeyed digest. Without obtaining an adequate license from the person(s) controlling the copyright in such materials, this document may not be modified outside the IETF Standards Process, and derivative works of it may not be created outside the IETF Standards Process, except to format it for publication as an RFC or to translate it into languages other than English. Now , In the Authorization header it shows that it is Basic Authorization followed by some random string .This String is the encoded (Base64) version of the credentials admin:aadd (including colon ) . The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. A replay attack against Digest Authentication would usually be pointless for a simple GET request since an eavesdropper would already have seen the only document he could obtain with a replay. It would achieve this by having the first 401 response include a domain parameter whose value includes a URI on the second server, and an opaque parameter whose value contains the state information. The initial registry contains the following entries: Each one of the algorithms defined in the registry might have a "-sess" variant, e.g., MD5-sess, SHA-256-sess, etc. The Digest Authentication scheme can also be used for authenticating users to proxies, proxies to proxies, or proxies to origin servers by use of the Proxy-Authenticate and Proxy-Authorization header fields. Pointer to specification text: RFC 7616. The security of this protocol is critically dependent on the randomness of the randomly chosen parameters, such as client and server nonces. But, for a large range of purposes, it is valuable as a replacement for Basic Authentication. The server MUST add these challenges to the response in order of preference, starting with the most preferred algorithm, followed by the less preferred algorithm. An HTTP/1.1 server MAY return multiple challenges with a 401 (Authenticate) response, and each challenge MAY use a different auth-scheme. Digest Authentication does not provide a strong authentication mechanism, when compared to public-key-based mechanisms, for example. Adds support for two new algorithms, SHA2-256 as mandatory and SHA2-512/256 as a backup, and defines the proper algorithm negotiation. If the "qop=auth-int" mechanism is used, those parts of the message used in the calculation of the WWW-Authenticate and Authorization header field response parameter values (see Section 3.2 above) are protected. If the user agent does not support the encoding indicated by the server, it can fail the request. If a proxy wants to authenticate a client before a request is forwarded to the server, it can be done using the Proxy-Authenticate and Proxy-Authorization header fields described in Section 3.8 below. If the one who receives an encrypted message doesn't have the key, the message cannot be recovered (decrypted). Even with the use of integrity protection, most metadata in header fields is not protected. Whereas Basic Authentication uses non-encrypted base64 encoding. It remedies some, but not all, weaknesses of Basic Authentication. To learn more, see our tips on writing great answers. No white space is allowed in any of the strings to which the digest function H() is applied, unless that white space exists in the quoted strings or entity body whose contents make up the string to be digested. Also, note that if integrity protection is applied (qop=auth-int), the H(entity-body) is the hash of the entity body, not the message body -- it is computed before any transfer encoding is applied by the sender and after it has been removed by the recipient. The bits in the digest are converted from the most significant to the least significant bit, four bits at a time, to the ASCII representation as follows. It can then find all the passwords within any subset of password space that would generate one of the nonce/response pairs in a single pass over that space. The first time the client requests the document, no Authorization header field is sent, so the server responds with: The client can prompt the user for their username and password, after which it will respond with a new request, including the following Authorization header field if the client chooses MD5 digest: If the client chooses to use the SHA-256 algorithm for calculating the response, the client responds with a new request including the following Authorization header field: The following example assumes that an access-protected document is being requested from the server via a GET request. However, it is significantly stronger than, e.g., CRAM-MD5, which has been proposed for use with Lightweight Directory Access Protocol (LDAP) [RFC4513] and IMAP/POP (see [RFC2195]). Right, and basic auth doesn't use hashed credentials, they are base64 encoded. As long as H(A1) is available to the server, the validity of an Authorization header field can be verified. The following is the operation that the client will perform to hash the username, using the same algorithm used to hash the credentials: Note that the value of many of the parameters, such as username value, are defined as a "quoted-string". By contrast, under Basic Authentication, once the eavesdropper has the user's password, any document protected by that password is open to him. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, how basic authentication is not encrypted ? How to generate a horizontal histogram with words? It was intended to replace the much weaker and even more dangerous Basic mechanism. The document keeps the MD5 algorithm support but only for backward compatibility. The cost of computing the response for each password on the list is paid once for each challenge. The size of the digest depends on the algorithm used. The slowness of the SSL can be cancelled out by the speed of only making one request. Adds various internationalization considerations that impact the A1 calculation and username and password encoding. As soon as the client types the credentials requested by the server , the Password is converted to a response using an algorithm and then is sent to the server , If the server Database has same response as given by the client the server gives the access to the resource , otherwise a 401 error . If Digest Authentication is being used, it SHOULD be over a secure channel like HTTPS [RFC2818]. On subsequent responses, the server sends Proxy-Authentication-Info with parameters the same as those for the Authentication-Info header field. A user agent MUST choose to use the strongest auth-scheme it understands and request credentials from the user based upon that challenge. For applications where no possibility of replay attack can be tolerated, the server can use one-time nonce values that will not be honored for a second use. The authenticating server MUST assure that the resource designated by the "uri" parameter is the same as the resource specified in the Request-Line; if they are not, the server SHOULD return a 400 Bad Request error. Enable the Digest authentication on the selected directory. Also, IP address spoofing is not that hard. HTTP provides a simple challenge-response authentication mechanism that may be used by a server to challenge a client request and by a client to provide authentication information. Encoding and encrypting are not the same thing. For historical reasons, a sender MUST NOT generate the quoted string syntax values for the following parameters: stale and algorithm. Authentication Scheme Name: Digest. Therefore, Basic Authentication should generally only be used where transport layer security is provided such as https. In our example, we created a user account named GOHAN. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. The authors would like to thank Paul Kyzivat and Dale Worley for their careful review and feedback on some aspects of this document. What is the difference between the following two t-statistics? The authors would like to thank Jonathan Stoke, Nico Williams, Harry Halpin, and Phil Hunt for their comments on the mailing list when discussing various aspects of this document. The Authorization header field MAY be included preemptively; doing so improves server efficiency and avoids extra round trips for authentication challenges. Why are only 2 out of the 3 boosters on Falcon Heavy reused? Thanks for contributing an answer to Stack Overflow! The only allowed value is "UTF-8", to be matched case-insensitively (see Section 2.3 in [RFC2978]). Would it be illegal for me to act as a Civillian Traffic Enforcer? rev2022.11.3.43005. Unlike Digest, you can store the passwords on the server in whatever encryption method you like, such as bcrypt, making the passwords more secure, In Summary if you have control of the clients, or can ensure they use SSL, HTTP Basic is a good choice. The person(s) controlling the copyright in some of this material may not have granted the IETF Trust the right to allow modifications of such material outside the IETF Standards Process. The client response to a WWW-Authenticate challenge for a protection space starts an authentication session with that protection space. For this reason, the client SHOULD always use the strongest scheme that it understands from the choices offered. Digest Access Authentication uses the hashing(i.e digest means cut into small pieces) methodologies to generate the cryptographic result.