Bugzilla Bug 282610: added a README file. Describe what svrcore is and

how it is being used.

security/svrcore/README

@@ -0,0 +1,48 @@
+The Netscape svrcore library
+
+Terry Hayes wrote the Netscape svrcore library in 1998.
+Valerie Chu wrote the ntgetpin.c and related files.
+
+svrcore used to contain two major parts.
+
+The first part is what we released on mozilla.  It is a kind of
+object-oriented package for handling PIN requests from NSS. The
+idea was to provide a standard way for servers to allow PIN input
+from a file or from the terminal.  There is also a PIN handler
+that caches the PIN in memory after encrypting it with a key on
+a device (such as a Fortezza card). This allowed a server to
+restart without having to reenter the PIN. However since the PIN
+is encrypted, a core dump would not expose it.  In addition,
+removing the device would also make the PIN inaccessible.
+
+The files are:
+
+svrcore.h - API definition
+alt.c - allows two possible PIN request methods to be used (say
+        file and then terminal)
+cache.c - caches the result from another PIN request method
+errors.c - error text
+file.c - reads the PIN from a specified file
+ntgetpin.c - Windows version of a user prompt for PIN
+ntgetpin.rc - Windows resource script for ntgetpin.c
+ntresource.h - a generated include file used by ntgetpin.rc
+key.ico - an icon used by ntgetpin.rc
+logo.ico - an icon used by ntgetpin.rc
+pin.c - functions to register a PIN request object with NSS
+pk11.c - implementation of the encrypted in-memory caching
+std.c - a "standard" PIN object that satisfies requests from a
+        file or the terminal and allows caching if desired.
+user.c - prompts the user for the PIN
+
+Note: the pk11.c file (secure PIN store) is a pretty good example
+of how to encrypt/decrypt with NSS.
+
+There was a second component of svrcore that handled export policy
+configuration.  It allowed patching of a single executable (single
+program build) to create the export and domestic versions of a
+server.  This code was discontinued after the export policy changes.
+
+The LDAP C SDK tools use svrcore.  They also implemented their
+own PIN object to allow command line PIN entry.  The directory
+server also implemented its own PIN object to allow a watchdog
+process to cache the PIN and restart the server.