1=pod
2
3=for openssl foreign manual errno(3)
4
5=head1 NAME
6
7ERR_raise, ERR_raise_data,
8ERR_put_error, ERR_add_error_data, ERR_add_error_vdata,
9ERR_add_error_txt, ERR_add_error_mem_bio
10- record an error
11
12=head1 SYNOPSIS
13
14 #include <openssl/err.h>
15
16 void ERR_raise(int lib, int reason);
17 void ERR_raise_data(int lib, int reason, const char *fmt, ...);
18
19 void ERR_add_error_data(int num, ...);
20 void ERR_add_error_vdata(int num, va_list arg);
21 void ERR_add_error_txt(const char *sep, const char *txt);
22 void ERR_add_error_mem_bio(const char *sep, BIO *bio);
23
24Deprecated since OpenSSL 3.0:
25
26 void ERR_put_error(int lib, int func, int reason, const char *file, int line);
27
28=head1 DESCRIPTION
29
30ERR_raise() adds a new error to the thread's error queue.  The
31error occurred in the library B<lib> for the reason given by the
32B<reason> code.  Furthermore, the name of the file, the line, and name
33of the function where the error occurred is saved with the error
34record.
35
36ERR_raise_data() does the same thing as ERR_raise(), but also lets the
37caller specify additional information as a format string B<fmt> and an
38arbitrary number of values, which are processed with L<BIO_snprintf(3)>.
39
40ERR_put_error() adds an error code to the thread's error queue. It
41signals that the error of reason code B<reason> occurred in function
42B<func> of library B<lib>, in line number B<line> of B<file>.
43This function is usually called by a macro.
44
45ERR_add_error_data() associates the concatenation of its B<num> string
46arguments as additional data with the error code added last.
47ERR_add_error_vdata() is similar except the argument is a B<va_list>.
48Multiple calls to these functions append to the current top of the error queue.
49The total length of the string data per error is limited to 4096 characters.
50
51ERR_add_error_txt() appends the given text string as additional data to the
52last error queue entry, after inserting the optional separator string if it is
53not NULL and the top error entry does not yet have additional data.
54In case the separator is at the end of the text it is not appended to the data.
55The B<sep> argument may be for instance "\n" to insert a line break when needed.
56If the associated data would become more than 4096 characters long
57(which is the limit given above)
58it is split over sufficiently many new copies of the last error queue entry.
59
60ERR_add_error_mem_bio() is the same as ERR_add_error_txt() except that
61the text string is taken from the given memory BIO.
62It appends '\0' to the BIO contents if not already NUL-terminated.
63
64L<ERR_load_strings(3)> can be used to register
65error strings so that the application can a generate human-readable
66error messages for the error code.
67
68=head2 Reporting errors
69
70=head3 OpenSSL library reports
71
72Each OpenSSL sub-library has library code B<ERR_LIB_XXX> and has its own set
73of reason codes B<XXX_R_...>.  These are both passed in combination to
74ERR_raise() and ERR_raise_data(), and the combination ultimately produces
75the correct error text for the reported error.
76
77All these macros and the numbers they have as values are specific to
78OpenSSL's libraries.  OpenSSL reason codes normally consist of textual error
79descriptions. For example, the function ssl3_read_bytes() reports a
80"handshake failure" as follows:
81
82 ERR_raise(ERR_LIB_SSL, SSL_R_SSL_HANDSHAKE_FAILURE);
83
84There are two exceptions:
85
86=over 4
87
88=item B<ERR_LIB_SYS>
89
90This "library code" indicates that a system error is being reported.  In
91this case, the reason code given to ERR_raise() and ERR_raise_data() I<must>
92be L<errno(3)>.
93
94 ERR_raise(ERR_LIB_SYS, errno);
95
96=item B<ERR_R_XXX>
97
98This set of error codes is considered global, and may be used in combination
99with any sub-library code.
100
101 ERR_raise(ERR_LIB_RSA, ERR_R_PASSED_INVALID_ARGUMENT);
102
103=back
104
105=head3 Other pieces of software
106
107Other pieces of software that may want to use OpenSSL's error reporting
108system, such as engines or applications, must normally get their own
109numbers.
110
111=over 4
112
113=item *
114
115To get a "library" code, call L<ERR_get_next_error_library(3)>; this gives
116the calling code a dynamic number, usable for the duration of the process.
117
118=item *
119
120Reason codes for each such "library" are determined or generated by the
121authors of that code.  They must be numbers in the range 1 to 524287 (in
122other words, they must be nonzero unsigned 18 bit integers).
123
124=back
125
126The exceptions mentioned in L</OpenSSL library reports> above are valid for
127other pieces of software, i.e. they may use B<ERR_LIB_SYS> to report system
128errors:
129
130 ERR_raise(ERR_LIB_SYS, errno);
131
132... and they may use B<ERR_R_XXX> macros together with their own "library"
133code.
134
135 int app_lib_code = ERR_get_next_error_library();
136
137 /* ... */
138
139 ERR_raise(app_lib_code, ERR_R_PASSED_INVALID_ARGUMENT);
140
141=begin comment
142
143[These are OpenSSL specific recommendations]
144
145Reason codes should consist of uppercase characters, numbers and underscores
146only. The error file generation script translates the trailing section of a
147reason code (after the "_R_") into lowercase with underscores changed to
148spaces.
149
150Although a library will normally report errors using its own specific
151B<ERR_LIB_XXX> macro, another library's macro can be used, together with
152that other library's reason codes. This is normally only done when a library
153wants to include ASN1 code which must be combined with B<ERR_LIB_ASN1>
154macro.
155
156=end comment
157
158=head1 RETURN VALUES
159
160ERR_raise(), ERR_raise_data(), ERR_put_error(),
161ERR_add_error_data(), ERR_add_error_vdata()
162ERR_add_error_txt(), and ERR_add_error_mem_bio()
163return no values.
164
165=head1 NOTES
166
167ERR_raise(), ERR_raise() and ERR_put_error() are implemented as macros.
168
169=head1 SEE ALSO
170
171L<ERR_load_strings(3)>, L<ERR_get_next_error_library(3)>
172
173=head1 HISTORY
174
175ERR_raise, ERR_raise_data, ERR_add_error_txt() and ERR_add_error_mem_bio()
176were added in OpenSSL 3.0.
177
178=head1 COPYRIGHT
179
180Copyright 2000-2020 The OpenSSL Project Authors. All Rights Reserved.
181
182Licensed under the Apache License 2.0 (the "License").  You may not use
183this file except in compliance with the License.  You can obtain a copy
184in the file LICENSE in the source distribution or at
185L<https://www.openssl.org/source/license.html>.
186
187=cut
188