get rid of Makefile.ssl in util/

[openssl.git] / FAQ

diff --git a/FAQ b/FAQ
index 25e101adbb125034fe48dbf924be19ffda14edf6..06faf91a5e92f852c9bba06b91bbc01ba5df3ea1 100644 (file)
--- 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?
 * 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?
 * 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?
 * 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?

 
 ===============================================================================
 
 
 ===============================================================================
 


@@ -68,7 +70,7 @@ OpenSSL  -  Frequently Asked Questions
 * Which is the current version of OpenSSL?
 
 The current version is available from <URL: http://www.openssl.org>.
 * Which is the current version of OpenSSL?
 
 The current version is available from <URL: http://www.openssl.org>.

-OpenSSL 0.9.7c was released on September 30, 2003.
+OpenSSL 0.9.7g was released on April 11, 2005.

 
 In addition to the current stable release, you can also access daily
 snapshots of the OpenSSL development version at <URL:
 
 In addition to the current stable release, you can also access daily
 snapshots of the OpenSSL development version at <URL:


@@ -150,7 +152,8 @@ Use MD5 to check that a tarball from a mirror site is identical:
    md5sum TARBALL | awk '{print $1;}' | cmp - TARBALL.md5
 
 You can check authenticity using pgp or gpg. You need the OpenSSL team
    md5sum TARBALL | awk '{print $1;}' | cmp - TARBALL.md5
 
 You can check authenticity using pgp or gpg. You need the OpenSSL team

-member public key used to sign it (download it from a key server). Then
+member public key used to sign it (download it from a key server, see a
+list of keys at <URL: http://www.openssl.org/about/>). Then

 just do:
 
    pgp TARBALL.asc
 just do:
 
    pgp TARBALL.asc


@@ -164,8 +167,8 @@ you if you want to use OpenSSL.  For information on intellectual
 property rights, please consult a lawyer.  The OpenSSL team does not
 offer legal advice.
 
 property rights, please consult a lawyer.  The OpenSSL team does not
 offer legal advice.
 

-You can configure OpenSSL so as not to use RC5 and IDEA by using
- ./config no-rc5 no-idea
+You can configure OpenSSL so as not to use IDEA, MDC2 and RC5 by using
+ ./config no-idea no-mdc2 no-rc5

 
 
 * Can I use OpenSSL with GPL software?
 
 
 * Can I use OpenSSL with GPL software?


@@ -470,6 +473,10 @@ This will only compile sha_dgst.c with -O0, the rest with the optimization
 level chosen by the configuration process.  When the above is done, do the
 test and installation and you're set.
 
 level chosen by the configuration process.  When the above is done, do the
 test and installation and you're set.
 

+3. Reconfigure the toolkit with no-sha0 option to leave out SHA0. It 
+should not be used and is not used in SSL/TLS nor any other recognized
+protocol in either case.
+

 
 * Why does the OpenSSL compilation fail with "ar: command not found"?
 
 
 * Why does the OpenSSL compilation fail with "ar: command not found"?
 


@@ -683,6 +690,20 @@ and attempts to free the buffer will have unpredictable results
 because it no longer points to the same address.
 
 
 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
 * 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 +786,28 @@ The correct name according to RFC2256 (LDAP) is x500UniqueIdentifier.
 Change your code to use the new name when compiling against OpenSSL 0.9.7.
 
 
 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 following:
+
+Thread-local cleanup functions:
+
+  ERR_remove_state()
+
+Application-global cleanup functions that are aware of usage (and therefore
+thread-safe):
+
+  ENGINE_cleanup() and CONF_modules_unload()
+
+"Brutal" (thread-unsafe) Application-global cleanup functions:
+
+  ERR_free_strings(), EVP_cleanup() and CRYPTO_cleanup_all_ex_data().
+
+

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