From: Dr. Stephen Henson <steve@openssl.org>
Date: Wed, 11 Aug 2004 17:22:13 +0000 (+0000)
Subject: Update FAQ.
X-Git-Tag: BEN_FIPS_TEST_6~14^2~101
X-Git-Url: https://git.openssl.org/?p=openssl.git;a=commitdiff_plain;h=6ef7b78e7c9be118da1ebd6a634b2bb9cbf63b6b;hp=e08aad1d14765aea1c391cf5b72967b41c801a83

Update FAQ.
---

diff --git a/FAQ b/FAQ
index 25e101adbb..45a1deadef 100644
--- a/FAQ
+++ b/FAQ
@@ -52,6 +52,7 @@ OpenSSL  -  Frequently Asked Questions
 * Is OpenSSL thread-safe?
 * I've compiled a program under Windows and it crashes: why?
 * How do I read or write a DER encoded buffer using the ASN1 functions?
+* OpenSSL uses DER but I need BER format: does OpenSSL support BER?
 * I've tried using <M_some_evil_pkcs12_macro> and I get errors why?
 * I've called <some function> and it fails, why?
 * I just get a load of numbers for the error output, what do they mean?
@@ -60,6 +61,7 @@ OpenSSL  -  Frequently Asked Questions
 * Can I use OpenSSL's SSL library with non-blocking I/O?
 * Why doesn't my server application receive a client certificate?
 * Why does compilation fail due to an undefined symbol NID_uniqueIdentifier?
+* I think I've detected a memory leak, is this a bug?
 
 ===============================================================================
 
@@ -683,6 +685,20 @@ and attempts to free the buffer will have unpredictable results
 because it no longer points to the same address.
 
 
+* OpenSSL uses DER but I need BER format: does OpenSSL support BER?
+
+The short answer is yes, because DER is a special case of BER and OpenSSL
+ASN1 decoders can process BER.
+
+The longer answer is that ASN1 structures can be encoded in a number of
+different ways. One set of ways is the Basic Encoding Rules (BER) with various
+permissible encodings. A restriction of BER is the Distinguished Encoding
+Rules (DER): these uniquely specify how a given structure is encoded.
+
+Therefore, because DER is a special case of BER, DER is an acceptable encoding
+for BER.
+
+
 * I've tried using <M_some_evil_pkcs12_macro> and I get errors why?
 
 This usually happens when you try compiling something using the PKCS#12
@@ -765,5 +781,17 @@ The correct name according to RFC2256 (LDAP) is x500UniqueIdentifier.
 Change your code to use the new name when compiling against OpenSSL 0.9.7.
 
 
+* I think I've detected a memory leak, is this a bug?
+
+In most cases the cause of an apparent memory leak is an OpenSSL internal table
+that is allocated when an application starts up. Since such tables do not grow
+in size over time they are harmless.
+
+These internal tables can be freed up when an application closes using various
+functions.  Currently these include: EVP_cleanup(), ERR_remove_state(),
+ERR_free_strings(), ENGINE_cleanup(), CONF_modules_unload() and
+CRYPTO_cleanup_all_ex_data().
+
+
 ===============================================================================