2 ''' $RCSfile$$Revision$$Date$
20 .ie \\n(.$>=3 .ne \\$3
36 ''' Set up \*(-- to give an unbreakable dash;
37 ''' string Tr holds user defined translation string.
38 ''' Bell System Logo is used as a dummy character.
44 .if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
45 .if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch
48 ''' \*(M", \*(S", \*(N" and \*(T" are the equivalent of
49 ''' \*(L" and \*(R", except that they are used on ".xx" lines,
50 ''' such as .IP and .SH, which do another additional levels of
51 ''' double-quote interpretation
80 .\" If the F register is turned on, we'll generate
81 .\" index entries out stderr for the following things:
86 .\" X<> Xref (embedded
87 .\" Of course, you have to process the output yourself
88 .\" in some meaninful fashion.
91 .tm Index:\\$1\t\\n%\t"\\$2"
96 .TH SSL_get_error 3 "0.9.7d" "2/Sep/2004" "OpenSSL"
100 .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
101 .de CQ \" put $1 in typewriter font
107 \\&\\$2 \\$3 \\$4 \\$5 \\$6 \\$7
110 .\" @(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2
111 . \" AM - accent mark definitions
113 . \" fudge factors for nroff and troff
122 . ds #H ((1u-(\\\\n(.fu%2u))*.13m)
128 . \" simple accents for nroff and troff
141 . ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
142 . ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
143 . ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
144 . ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
145 . ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
146 . ds ? \s-2c\h'-\w'c'u*7/10'\u\h'\*(#H'\zi\d\s+2\h'\w'c'u*8/10'
147 . ds ! \s-2\(or\s+2\h'-\w'\(or'u'\v'-.8m'.\v'.8m'
148 . ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
149 . ds q o\h'-\w'o'u*8/10'\s-4\v'.4m'\z\(*i\v'-.4m'\s+4\h'\w'o'u*8/10'
151 . \" troff and (daisy-wheel) nroff accents
152 .ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
153 .ds 8 \h'\*(#H'\(*b\h'-\*(#H'
154 .ds v \\k:\h'-(\\n(.wu*9/10-\*(#H)'\v'-\*(#V'\*(#[\s-4v\s0\v'\*(#V'\h'|\\n:u'\*(#]
155 .ds _ \\k:\h'-(\\n(.wu*9/10-\*(#H+(\*(#F*2/3))'\v'-.4m'\z\(hy\v'.4m'\h'|\\n:u'
156 .ds . \\k:\h'-(\\n(.wu*8/10)'\v'\*(#V*4/10'\z.\v'-\*(#V*4/10'\h'|\\n:u'
157 .ds 3 \*(#[\v'.2m'\s-2\&3\s0\v'-.2m'\*(#]
158 .ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
159 .ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
160 .ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
161 .ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
162 .ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
163 .ds ae a\h'-(\w'a'u*4/10)'e
164 .ds Ae A\h'-(\w'A'u*4/10)'E
165 .ds oe o\h'-(\w'o'u*4/10)'e
166 .ds Oe O\h'-(\w'O'u*4/10)'E
167 . \" corrections for vroff
168 .if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
169 .if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
170 . \" for low resolution devices (crt and lpr)
171 .if \n(.H>23 .if \n(.V>19 \
175 . ds v \h'-1'\o'\(aa\(ga'
191 SSL_get_error \- obtain result code for TLS/SSL I/O operation
195 \& #include <openssl/ssl.h>
198 \& int SSL_get_error(SSL *ssl, int ret);
201 \fISSL_get_error()\fR returns a result code (suitable for the C \*(L"switch\*(R"
202 statement) for a preceding call to \fISSL_connect()\fR, \fISSL_accept()\fR, \fISSL_do_handshake()\fR,
203 \fISSL_read()\fR, \fISSL_peek()\fR, or \fISSL_write()\fR on \fBssl\fR. The value returned by
204 that TLS/SSL I/O function must be passed to \fISSL_get_error()\fR in parameter
207 In addition to \fBssl\fR and \fBret\fR, \fISSL_get_error()\fR inspects the
208 current thread's OpenSSL error queue. Thus, \fISSL_get_error()\fR must be
209 used in the same thread that performed the TLS/SSL I/O operation, and no
210 other OpenSSL function calls should appear in between. The current
211 thread's error queue must be empty before the TLS/SSL I/O operation is
212 attempted, or \fISSL_get_error()\fR will not work reliably.
214 The following return values can currently occur:
215 .Ip "\s-1SSL_ERROR_NONE\s0" 4
216 The \s-1TLS/SSL\s0 I/O operation completed. This result code is returned
217 if and only if \fBret > 0\fR.
218 .Ip "\s-1SSL_ERROR_ZERO_RETURN\s0" 4
219 The \s-1TLS/SSL\s0 connection has been closed. If the protocol version is \s-1SSL\s0 3.0
220 or \s-1TLS\s0 1.0, this result code is returned only if a closure
221 alert has occurred in the protocol, i.e. if the connection has been
222 closed cleanly. Note that in this case \fB\s-1SSL_ERROR_ZERO_RETURN\s0\fR
223 does not necessarily indicate that the underlying transport
225 .Ip "\s-1SSL_ERROR_WANT_READ\s0, \s-1SSL_ERROR_WANT_WRITE\s0" 4
226 The operation did not complete; the same \s-1TLS/SSL\s0 I/O function should be
227 called again later. If, by then, the underlying \fB\s-1BIO\s0\fR has data
228 available for reading (if the result code is \fB\s-1SSL_ERROR_WANT_READ\s0\fR)
229 or allows writing data (\fB\s-1SSL_ERROR_WANT_WRITE\s0\fR), then some \s-1TLS/SSL\s0
230 protocol progress will take place, i.e. at least part of an \s-1TLS/SSL\s0
231 record will be read or written. Note that the retry may again lead to
232 a \fB\s-1SSL_ERROR_WANT_READ\s0\fR or \fB\s-1SSL_ERROR_WANT_WRITE\s0\fR condition.
233 There is no fixed upper limit for the number of iterations that
234 may be necessary until progress becomes visible at application
237 For socket \fB\s-1BIO\s0\fRs (e.g. when \fISSL_set_fd()\fR was used), \fIselect()\fR or
238 \fIpoll()\fR on the underlying socket can be used to find out when the
239 \s-1TLS/SSL\s0 I/O function should be retried.
241 Caveat: Any \s-1TLS/SSL\s0 I/O function can lead to either of
242 \fB\s-1SSL_ERROR_WANT_READ\s0\fR and \fB\s-1SSL_ERROR_WANT_WRITE\s0\fR. In particular,
243 \fISSL_read()\fR or \fISSL_peek()\fR may want to write data and \fISSL_write()\fR may want
244 to read data. This is mainly because \s-1TLS/SSL\s0 handshakes may occur at any
245 time during the protocol (initiated by either the client or the server);
246 \fISSL_read()\fR, \fISSL_peek()\fR, and \fISSL_write()\fR will handle any pending handshakes.
247 .Ip "\s-1SSL_ERROR_WANT_CONNECT\s0, \s-1SSL_ERROR_WANT_ACCEPT\s0" 4
248 The operation did not complete; the same \s-1TLS/SSL\s0 I/O function should be
249 called again later. The underlying \s-1BIO\s0 was not connected yet to the peer
250 and the call would block in \fIconnect()\fR/\fIaccept()\fR. The \s-1SSL\s0 function should be
251 called again when the connection is established. These messages can only
252 appear with a \fIBIO_s_connect()\fR or \fIBIO_s_accept()\fR \s-1BIO\s0, respectively.
253 In order to find out, when the connection has been successfully established,
254 on many platforms \fIselect()\fR or \fIpoll()\fR for writing on the socket file descriptor
256 .Ip "\s-1SSL_ERROR_WANT_X509_LOOKUP\s0" 4
257 The operation did not complete because an application callback set by
258 \fISSL_CTX_set_client_cert_cb()\fR has asked to be called again.
259 The \s-1TLS/SSL\s0 I/O function should be called again later.
260 Details depend on the application.
261 .Ip "\s-1SSL_ERROR_SYSCALL\s0" 4
262 Some I/O error occurred. The OpenSSL error queue may contain more
263 information on the error. If the error queue is empty
264 (i.e. \fIERR_get_error()\fR returns 0), \fBret\fR can be used to find out more
265 about the error: If \fBret == 0\fR, an \s-1EOF\s0 was observed that violates
266 the protocol. If \fBret == \-1\fR, the underlying \fB\s-1BIO\s0\fR reported an
267 I/O error (for socket I/O on Unix systems, consult \fBerrno\fR for details).
268 .Ip "\s-1SSL_ERROR_SSL\s0" 4
269 A failure in the \s-1SSL\s0 library occurred, usually a protocol error. The
270 OpenSSL error queue contains more information on the error.
274 \fISSL_get_error()\fR was added in SSLeay 0.8.
277 .IX Title "SSL_get_error 3"
278 .IX Name "SSL_get_error - obtain result code for TLS/SSL I/O operation"
282 .IX Header "SYNOPSIS"
284 .IX Header "DESCRIPTION"
286 .IX Header "RETURN VALUES"
288 .IX Item "\s-1SSL_ERROR_NONE\s0"
290 .IX Item "\s-1SSL_ERROR_ZERO_RETURN\s0"
292 .IX Item "\s-1SSL_ERROR_WANT_READ\s0, \s-1SSL_ERROR_WANT_WRITE\s0"
294 .IX Item "\s-1SSL_ERROR_WANT_CONNECT\s0, \s-1SSL_ERROR_WANT_ACCEPT\s0"
296 .IX Item "\s-1SSL_ERROR_WANT_X509_LOOKUP\s0"
298 .IX Item "\s-1SSL_ERROR_SYSCALL\s0"
300 .IX Item "\s-1SSL_ERROR_SSL\s0"
302 .IX Header "SEE ALSO"