Add FAQ about AKID.

[openssl.git] / FAQ

diff --git a/FAQ b/FAQ
index 889eb0ac43bc0322a198c86796c5225243376854..44bf0567edc513f3893c1c598da63ebaea1db46c 100644 (file)
--- a/FAQ
+++ b/FAQ
@@ -32,6 +32,7 @@ OpenSSL  -  Frequently Asked Questions
 * How do I install a CA certificate into a browser?
 * Why is OpenSSL x509 DN output not conformant to RFC2253?
 * What is a "128 bit certificate"? Can I create one with OpenSSL?
+* Why does OpenSSL set the authority key identifier extension incorrectly?
 
 [BUILD] Questions about building and testing OpenSSL
 
@@ -49,6 +50,7 @@ OpenSSL  -  Frequently Asked Questions
 * Why does OpenBSD-i386 build fail on des-586.s with "Unimplemented segment type"?
 * Why does the OpenSSL test suite fail in sha512t on x86 CPU?
 * Why does compiler fail to compile sha512.c?
+* Test suite still fails, what to do?
 
 [PROG] Questions about programming with OpenSSL
 
@@ -424,6 +426,25 @@ The export laws were later changed to allow almost unrestricted use of strong
 encryption so these certificates are now obsolete.
 
 
+* Why does OpenSSL set the authority key identifier AKID) extension incorrectly?
+
+It doesn't: this extension is often the cause of confusion.
+
+Consider a certificate chain A->B->C so that A signs, B and B signs C. Suppose
+certificate C contains AKID.
+
+The purpose of this extension is to identify the authority certificate B. This
+can be done either by including the subject key identifier of B or its issuer
+name and serial number.
+
+In this latter case because it is identifying certifcate B it must contain the
+issuer name and serial number of B.
+
+It is often wrongly assumed that it should contain the issuer name of C. If it
+did this would be redundant information because it would duplicate the issuer
+name of C.
+
+
 [BUILD] =======================================================================
 
 * Why does the linker complain about undefined symbols?
@@ -655,6 +676,18 @@ the module in question. The recommendation is to disable SHA-512 by
 adding no-sha512 to ./config [or ./Configure] command line. Another
 possible alternative might be to switch to GCC.
 
+* Test suite still fails, what to do?
+
+Another common reason for failure to complete some particular test is
+simply bad code generated by a buggy component in toolchain or deficiency
+in run-time environment. There are few cases documented in PROBLEMS file,
+consult it for possible workaround before you beat the drum. Even if you
+don't find solution or even mention there, do reserve for possibility of
+a compiler bug. Compiler bugs might appear in rather bizarre ways, they
+never make sense, and tend to emerge when you least expect them. In order
+to identify one, drop optimization level, e.g. by editing CFLAG line in
+top-level Makefile, recompile and re-run the test.
+
 [PROG] ========================================================================
 
 * Is OpenSSL thread-safe?
@@ -687,10 +720,10 @@ your application must link  against the same by which OpenSSL was
 built.  If you are using MS Visual C++ (Studio) this can be changed
 by:
 
-1.  Select Settings... from the Project Menu.
-2.  Select the C/C++ Tab.
-3.  Select "Code Generation from the "Category" drop down list box
-4.  Select the Appropriate library (see table below) from the "Use
+ 1. Select Settings... from the Project Menu.
+ 2. Select the C/C++ Tab.
+ 3. Select "Code Generation from the "Category" drop down list box
+ 4. Select the Appropriate library (see table below) from the "Use
     run-time library" drop down list box.  Perform this step for both
     your debug and release versions of your application (look at the
     top left of the settings panel to change between the two)