=head1 DESCRIPTION
-If available (see L</NOTES> below), the application can request
+If available (see L</Configure Tracing> below), the application can request
internal trace output.
This output comes in form of free text for humans to read.
The trace output is divided into categories which can be
enabled individually.
-Every category can be enabled individually by attaching a so called
+Every category can be enabled individually by attaching a so-called
I<trace channel> to it, which in the simplest case is just a BIO object
to which the application can write the tracing output for this category.
Alternatively, the application can provide a tracer callback in order to
These are called a I<simple trace channel> and a I<callback trace channel>,
respectively.
+L<OSSL_TRACE_ENABLED(3)> can be used to check whether tracing is currently
+enabled for the given category.
+Functions like L<OSSL_TRACE1(3)> and macros like L<OSSL_TRACE_BEGIN(3)>
+can be used for producing free-text trace output.
+
=head2 Functions
OSSL_trace_set_channel() is used to enable the given trace C<category>
-by attaching the B<BIO> C<bio> object as (simple) trace channel.
+by attaching the B<BIO> I<bio> object as (simple) trace channel.
+On success the ownership of the BIO is transferred to the channel,
+so the caller must not free it directly.
OSSL_trace_set_prefix() and OSSL_trace_set_suffix() can be used to add
an extra line for each channel, to be output before and after group of
tracing output.
-What constitues an output group is decided by the code that produces
+What constitutes an output group is decided by the code that produces
the output.
The lines given here are considered immutable; for more dynamic
tracing prefixes, consider setting a callback with
OSSL_trace_set_callback() instead.
OSSL_trace_set_callback() is used to enable the given trace
-C<category> by giving it the tracer callback C<cb> with the associated
-data C<data>, which will simply be passed through to C<cb> whenever
+I<category> by giving it the tracer callback I<cb> with the associated
+data I<data>, which will simply be passed through to I<cb> whenever
it's called. The callback function is internally wrapped by a
-dedicated BIO object, the so called I<callback trace channel>.
+dedicated BIO object, the so-called I<callback trace channel>.
This should be used when it's desirable to do form the trace output to
something suitable for application needs where a prefix and suffix
line aren't enough.
exclusive, calling one of them will clear whatever was set by the
previous call.
-Calling OSSL_trace_set_channel() with C<NULL> for C<channel> or
-OSSL_trace_set_callback() with C<NULL> for C<cb> disables tracing for
-the given C<category>
+Calling OSSL_trace_set_channel() with NULL for I<channel> or
+OSSL_trace_set_callback() with NULL for I<cb> disables tracing for
+the given I<category>.
=head2 Trace callback
-The tracer callback must return a C<size_t>, which must be zero on
+The tracer callback must return a B<size_t>, which must be zero on
error and otherwise return the number of bytes that were output.
-It receives a text buffer C<buf> with C<cnt> bytes of text, as well as
-the C<category>, a control number C<cmd>, and the C<data> that was
+It receives a text buffer I<buf> with I<cnt> bytes of text, as well as
+the I<category>, a control number I<cmd>, and the I<data> that was
passed to OSSL_trace_set_callback().
The possible control numbers are:
=over 4
-=item C<OSSL_TRACE_CTRL_BEGIN>
+=item B<OSSL_TRACE_CTRL_BEGIN>
The callback is called from OSSL_trace_begin(), which gives the
callback the possibility to output a dynamic starting line, or set a
prefix that should be output at the beginning of each line, or
something other.
-=item C<OSSL_TRACE_CTRL_WRITE>
+=item B<OSSL_TRACE_CTRL_WRITE>
This callback is called whenever data is written to the BIO by some
regular BIO output routine.
-An arbitrary number of C<OSSL_TRACE_CTRL_WRITE> callbacks can occur
-inside a group marked by a pair of C<OSSL_TRACE_CTRL_BEGIN> and
-C<OSSL_TRACE_CTRL_END> calls, but never outside such a group.
+An arbitrary number of B<OSSL_TRACE_CTRL_WRITE> callbacks can occur
+inside a group marked by a pair of B<OSSL_TRACE_CTRL_BEGIN> and
+B<OSSL_TRACE_CTRL_END> calls, but never outside such a group.
-=item C<OSSL_TRACE_CTRL_END>
+=item B<OSSL_TRACE_CTRL_END>
The callback is called from OSSL_trace_end(), which gives the callback
the possibility to output a dynamic ending line, or reset the line
-prefix that was set with OSSL_TRACE_CTRL_BEGIN, or something other.
+prefix that was set with B<OSSL_TRACE_CTRL_BEGIN>, or something other.
=back
=over 4
-=item C<OSSL_TRACE_CATEGORY_TRACE>
+=item B<OSSL_TRACE_CATEGORY_TRACE>
Traces the OpenSSL trace API itself.
More precisely, this will generate trace output any time a new
trace hook is set.
-=item C<OSSL_TRACE_CATEGORY_INIT>
+=item B<OSSL_TRACE_CATEGORY_INIT>
Traces OpenSSL library initialization and cleanup.
A suggestion is to make such cleanup part of a function that's
registered very early with L<atexit(3)>.
-=item C<OSSL_TRACE_CATEGORY_TLS>
+=item B<OSSL_TRACE_CATEGORY_TLS>
Traces the TLS/SSL protocol.
-=item C<OSSL_TRACE_CATEGORY_TLS_CIPHER>
+=item B<OSSL_TRACE_CATEGORY_TLS_CIPHER>
Traces the ciphers used by the TLS/SSL protocol.
-=item C<OSSL_TRACE_CATEGORY_ENGINE_CONF>
+=item B<OSSL_TRACE_CATEGORY_CONF>
-Traces the ENGINE configuration.
+Traces details about the provider and engine configuration.
-=item C<OSSL_TRACE_CATEGORY_ENGINE_TABLE>
+=item B<OSSL_TRACE_CATEGORY_ENGINE_TABLE>
Traces the ENGINE algorithm table selection.
-More precisely, engine_table_select(), the function that is used by
-RSA, DSA (etc) code to select registered ENGINEs, cache defaults and
-functional references (etc), will generate trace summaries.
+More precisely, functions like ENGINE_get_pkey_asn1_meth_engine(),
+ENGINE_get_pkey_meth_engine(), ENGINE_get_cipher_engine(),
+ENGINE_get_digest_engine(), will generate trace summaries of the
+handling of internal tables.
-=item C<OSSL_TRACE_CATEGORY_ENGINE_REF_COUNT>
+=item B<OSSL_TRACE_CATEGORY_ENGINE_REF_COUNT>
-Tracds the ENGINE reference counting.
+Traces the ENGINE reference counting.
More precisely, both reference counts in the ENGINE structure will be
monitored with a line of trace output generated for each change.
-=item C<OSSL_TRACE_CATEGORY_PKCS5V2>
+=item B<OSSL_TRACE_CATEGORY_PKCS5V2>
Traces PKCS#5 v2 key generation.
-=item C<OSSL_TRACE_CATEGORY_PKCS12_KEYGEN>
+=item B<OSSL_TRACE_CATEGORY_PKCS12_KEYGEN>
Traces PKCS#12 key generation.
-=item C<OSSL_TRACE_CATEGORY_PKCS12_DECRYPT>
+=item B<OSSL_TRACE_CATEGORY_PKCS12_DECRYPT>
Traces PKCS#12 decryption.
-=item C<OSSL_TRACE_CATEGORY_X509V3_POLICY>
+=item B<OSSL_TRACE_CATEGORY_X509V3_POLICY>
Traces X509v3 policy processing.
More precisely, this generates the complete policy tree at various
point during evaluation.
-=item C<OSSL_TRACE_CATEGORY_BN_CTX>
+=item B<OSSL_TRACE_CATEGORY_BN_CTX>
Traces BIGNUM context operations.
-=item C<OSSL_TRACE_CATEGORY_PROVIDER_CONF>
+=item B<OSSL_TRACE_CATEGORY_CMP>
+
+Traces CMP client and server activity.
+
+=item B<OSSL_TRACE_CATEGORY_STORE>
+
+Traces STORE operations.
+
+=item B<OSSL_TRACE_CATEGORY_DECODER>
+
+Traces decoder operations.
+
+=item B<OSSL_TRACE_CATEGORY_ENCODER>
-Traces the OSSL_PROVIDER configuration.
+Traces encoder operations.
+
+=item B<OSSL_TRACE_CATEGORY_REF_COUNT>
+
+Traces decrementing certain ASN.1 structure references.
+
+=item B<OSSL_TRACE_CATEGORY_HTTP>
+
+Traces the HTTP client, such as message headers being sent and received.
=back
-There is also C<OSSL_TRACE_CATEGORY_ALL>, which works as a fallback
+There is also B<OSSL_TRACE_CATEGORY_ALL>, which works as a fallback
and can be used to get I<all> trace output.
Note, however, that in this case all trace output will effectively be
necessary to configure and build OpenSSL with the 'enable-trace' option.
When the library is built with tracing disabled, the macro
-C<OPENSSL_NO_TRACE> is defined in C<openssl/opensslconf.h> and all
+B<OPENSSL_NO_TRACE> is defined in F<< <openssl/opensslconf.h> >> and all
functions described here are inoperational, i.e. will do nothing.
+=head1 SEE ALSO
+
+L<OSSL_TRACE_ENABLED(3)>, L<OSSL_TRACE_BEGIN(3)>, L<OSSL_TRACE1(3)>,
+L<atexit(3)>
+
=head1 HISTORY
OSSL_trace_set_channel(), OSSL_trace_set_prefix(),
=head1 COPYRIGHT
-Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.
+Copyright 2019-2023 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the Apache License 2.0 (the "License"). You may not use
this file except in compliance with the License. You can obtain a copy
projects / openssl.git / blobdiff