818fd4a67d
This introduces a new generic SASL authentication method, similar to the GSS and SSPI methods. The server first tells the client which SASL authentication mechanism to use, and then the mechanism-specific SASL messages are exchanged in AuthenticationSASLcontinue and PasswordMessage messages. Only SCRAM-SHA-256 is supported at the moment, but this allows adding more SASL mechanisms in the future, without changing the overall protocol. Support for channel binding, aka SCRAM-SHA-256-PLUS is left for later. The SASLPrep algorithm, for pre-processing the password, is not yet implemented. That could cause trouble, if you use a password with non-ASCII characters, and a client library that does implement SASLprep. That will hopefully be added later. Authorization identities, as specified in the SCRAM-SHA-256 specification, are ignored. SET SESSION AUTHORIZATION provides more or less the same functionality, anyway. If a user doesn't exist, perform a "mock" authentication, by constructing an authentic-looking challenge on the fly. The challenge is derived from a new system-wide random value, "mock authentication nonce", which is created at initdb, and stored in the control file. We go through these motions, in order to not give away the information on whether the user exists, to unauthenticated users. Bumps PG_CONTROL_VERSION, because of the new field in control file. Patch by Michael Paquier and Heikki Linnakangas, reviewed at different stages by Robert Haas, Stephen Frost, David Steele, Aleksander Alekseev, and many others. Discussion: https://www.postgresql.org/message-id/CAB7nPqRbR3GmFYdedCAhzukfKrgBLTLtMvENOmPrVWREsZkF8g%40mail.gmail.com Discussion: https://www.postgresql.org/message-id/CAB7nPqSMXU35g%3DW9X74HVeQp0uvgJxvYOuA4A-A3M%2B0wfEBv-w%40mail.gmail.com Discussion: https://www.postgresql.org/message-id/55192AFE.6080106@iki.fi
The PostgreSQL contrib tree
---------------------------
This subtree contains porting tools, analysis utilities, and plug-in
features that are not part of the core PostgreSQL system, mainly
because they address a limited audience or are too experimental to be
part of the main source tree. This does not preclude their
usefulness.
User documentation for each module appears in the main SGML
documentation.
When building from the source distribution, these modules are not
built automatically, unless you build the "world" target. You can
also build and install them all by running "make all" and "make
install" in this directory; or to build and install just one selected
module, do the same in that module's subdirectory.
Some directories supply new user-defined functions, operators, or
types. To make use of one of these modules, after you have installed
the code you need to register the new SQL objects in the database
system by executing a CREATE EXTENSION command. In a fresh database,
you can simply do
CREATE EXTENSION module_name;
See the PostgreSQL documentation for more information about this
procedure.