9 #include <openssl/err.h>
11 unsigned long ERR_get_error(void);
12 unsigned long ERR_peek_error(void);
13 unsigned long ERR_get_error_line(const char **file, int *line);
14 unsigned long ERR_peek_error_line(const char **file, int *line);
15 unsigned long ERR_get_error_line_data(const char **file, int *line,
16 const char **data, int *flags);
17 unsigned long ERR_peek_error_line_data(const char **file, int *line,
18 const char **data, int *flags);
20 int ERR_GET_LIB(unsigned long e);
21 int ERR_GET_FUNC(unsigned long e);
22 int ERR_GET_REASON(unsigned long e);
24 void ERR_clear_error(void);
25 void ERR_remove_thread_state(void);
27 char *ERR_error_string(unsigned long e, char *buf);
28 const char *ERR_lib_error_string(unsigned long e);
29 const char *ERR_func_error_string(unsigned long e);
30 const char *ERR_reason_error_string(unsigned long e);
32 void ERR_print_errors(BIO *bp);
33 void ERR_print_errors_fp(FILE *fp);
35 void ERR_load_crypto_strings(void);
37 void ERR_put_error(int lib, int func, int reason, const char *file,
39 void ERR_add_error_data(int num, ...);
41 void ERR_load_strings(int lib,ERR_STRING_DATA str[]);
42 unsigned long ERR_PACK(int lib, int func, int reason);
43 int ERR_get_next_error_library(void);
47 #if OPENSSL_API_COMPAT < 0x10000000L
48 void ERR_remove_state(unsigned long pid);
51 #if OPENSSL_API_COMPAT < 0x10100000L
52 # define ERR_free_strings()
58 When a call to the OpenSSL library fails, this is usually signaled
59 by the return value, and an error code is stored in an error queue
60 associated with the current thread. The B<err> library provides
61 functions to obtain these error codes and textual error messages.
63 The L<ERR_get_error(3)> manpage describes how to
66 Error codes contain information about where the error occurred, and
67 what went wrong. L<ERR_GET_LIB(3)> describes how to
68 extract this information. A method to obtain human-readable error
69 messages is described in L<ERR_error_string(3)>.
71 L<ERR_clear_error(3)> can be used to clear the
74 Note that L<ERR_remove_thread_state(3)> should be used to
75 avoid memory leaks when threads are terminated.
77 =head1 ADDING NEW ERROR CODES TO OPENSSL
79 See L<ERR_put_error(3)> if you want to record error codes in the
80 OpenSSL error system from within your application.
82 The remainder of this section is of interest only if you want to add
83 new error codes to OpenSSL or add error codes from external libraries.
85 =head2 Reporting errors
87 Each sub-library has a specific macro XXXerr() that is used to report
88 errors. Its first argument is a function code B<XXX_F_...>, the second
89 argument is a reason code B<XXX_R_...>. Function codes are derived
90 from the function names; reason codes consist of textual error
91 descriptions. For example, the function ssl3_read_bytes() reports a
92 "handshake failure" as follows:
94 SSLerr(SSL_F_SSL3_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
96 Function and reason codes should consist of upper case characters,
97 numbers and underscores only. The error file generation script translates
98 function codes into function names by looking in the header files
99 for an appropriate function name, if none is found it just uses
100 the capitalized form such as "SSL3_READ_BYTES" in the above example.
102 The trailing section of a reason code (after the "_R_") is translated
103 into lower case and underscores changed to spaces.
105 When you are using new function or reason codes, run B<make errors>.
106 The necessary B<#define>s will then automatically be added to the
107 sub-library's header file.
109 Although a library will normally report errors using its own specific
110 XXXerr macro, another library's macro can be used. This is normally
111 only done when a library wants to include ASN1 code which must use
114 =head2 Adding new libraries
116 When adding a new sub-library to OpenSSL, assign it a library number
117 B<ERR_LIB_XXX>, define a macro XXXerr() (both in B<err.h>), add its
118 name to B<ERR_str_libraries[]> (in B<crypto/err/err.c>), and add
119 C<ERR_load_XXX_strings()> to the ERR_load_crypto_strings() function
120 (in B<crypto/err/err_all.c>). Finally, add an entry
122 L XXX xxx.h xxx_err.c
124 to B<crypto/err/openssl.ec>, and add B<xxx_err.c> to the Makefile.
125 Running B<make errors> will then generate a file B<xxx_err.c>, and
126 add all error codes used in the library to B<xxx.h>.
128 Additionally the library include file must have a certain form.
129 Typically it will initially look like this:
140 #include <openssl/bio.h>
141 #include <openssl/x509.h>
143 /* Macros, structures and function prototypes */
146 /* BEGIN ERROR CODES */
148 The B<BEGIN ERROR CODES> sequence is used by the error code
149 generation script as the point to place new error codes, any text
150 after this point will be overwritten when B<make errors> is run.
151 The closing #endif etc will be automatically added by the script.
153 The generated C error code file B<xxx_err.c> will load the header
154 files B<stdio.h>, B<openssl/err.h> and B<openssl/xxx.h> so the
155 header file must load any additional header files containing any
158 =head1 USING ERROR CODES IN EXTERNAL LIBRARIES
160 It is also possible to use OpenSSL's error code scheme in external
161 libraries. The library needs to load its own codes and call the OpenSSL
162 error code insertion script B<mkerr.pl> explicitly to add codes to
163 the header file and generate the C error code file. This will normally
164 be done if the external library needs to generate new ASN1 structures
165 but it can also be used to add more general purpose error code handling.
171 The error queues are stored in a thread-local storage with one B<ERR_STATE>
172 entry for each thread. ERR_get_state() returns the current thread's
173 B<ERR_STATE>. An B<ERR_STATE> can hold up to B<ERR_NUM_ERRORS> error
174 codes. When more error codes are added, the old ones are overwritten,
175 on the assumption that the most recent errors are most important.
177 Error strings are also stored in a hash table that can be obtained
178 by calling ERR_get_string_table(void).
182 L<CRYPTO_set_locking_callback(3)>,
185 L<ERR_clear_error(3)>,
186 L<ERR_error_string(3)>,
187 L<ERR_print_errors(3)>,
188 L<ERR_load_crypto_strings(3)>,
189 L<ERR_remove_thread_state(3)>,
191 L<ERR_load_strings(3)>,
196 The ERR_load_crypto_strings() function was deprecated in OpenSSL 1.1.0 by
197 OPENSSL_init_crypto().