PostgreSQL Source Code  git master
libpq-be.h
Go to the documentation of this file.
1 /*-------------------------------------------------------------------------
2  *
3  * libpq-be.h
4  * This file contains definitions for structures and externs used
5  * by the postmaster during client authentication.
6  *
7  * Note that this is backend-internal and is NOT exported to clients.
8  * Structs that need to be client-visible are in pqcomm.h.
9  *
10  *
11  * Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
12  * Portions Copyright (c) 1994, Regents of the University of California
13  *
14  * src/include/libpq/libpq-be.h
15  *
16  *-------------------------------------------------------------------------
17  */
18 #ifndef LIBPQ_BE_H
19 #define LIBPQ_BE_H
20 
21 #include <sys/time.h>
22 #ifdef USE_OPENSSL
23 #include <openssl/ssl.h>
24 #include <openssl/err.h>
25 #endif
26 #include <netinet/tcp.h>
27 
28 #ifdef ENABLE_GSS
29 #if defined(HAVE_GSSAPI_H)
30 #include <gssapi.h>
31 #else
32 #include <gssapi/gssapi.h>
33 #endif /* HAVE_GSSAPI_H */
34 #endif /* ENABLE_GSS */
35 
36 #ifdef ENABLE_SSPI
37 #define SECURITY_WIN32
38 #if defined(WIN32) && !defined(_MSC_VER)
39 #include <ntsecapi.h>
40 #endif
41 #include <security.h>
42 #undef SECURITY_WIN32
43 
44 #ifndef ENABLE_GSS
45 /*
46  * Define a fake structure compatible with GSSAPI on Unix.
47  */
48 typedef struct
49 {
50  void *value;
51  int length;
52 } gss_buffer_desc;
53 #endif
54 #endif /* ENABLE_SSPI */
55 
56 #include "datatype/timestamp.h"
57 #include "libpq/hba.h"
58 #include "libpq/pqcomm.h"
59 
60 
61 typedef enum CAC_state
62 {
70 
71 
72 /*
73  * GSSAPI specific state information
74  */
75 #if defined(ENABLE_GSS) | defined(ENABLE_SSPI)
76 typedef struct
77 {
78  gss_buffer_desc outbuf; /* GSSAPI output token buffer */
79 #ifdef ENABLE_GSS
80  gss_cred_id_t cred; /* GSSAPI connection cred's */
81  gss_ctx_id_t ctx; /* GSSAPI connection context */
82  gss_name_t name; /* GSSAPI client name */
83  char *princ; /* GSSAPI Principal used for auth, NULL if
84  * GSSAPI auth was not used */
85  bool auth; /* GSSAPI Authentication used */
86  bool enc; /* GSSAPI encryption in use */
87 #endif
88 } pg_gssinfo;
89 #endif
90 
91 /*
92  * ClientConnectionInfo includes the fields describing the client connection
93  * that are copied over to parallel workers as nothing from Port does that.
94  * The same rules apply for allocations here as for Port (everything must be
95  * malloc'd or palloc'd in TopMemoryContext).
96  *
97  * If you add a struct member here, remember to also handle serialization in
98  * SerializeClientConnectionInfo() and co.
99  */
100 typedef struct ClientConnectionInfo
101 {
102  /*
103  * Authenticated identity. The meaning of this identifier is dependent on
104  * auth_method; it is the identity (if any) that the user presented during
105  * the authentication cycle, before they were assigned a database role.
106  * (It is effectively the "SYSTEM-USERNAME" of a pg_ident usermap --
107  * though the exact string in use may be different, depending on pg_hba
108  * options.)
109  *
110  * authn_id is NULL if the user has not actually been authenticated, for
111  * example if the "trust" auth method is in use.
112  */
113  const char *authn_id;
114 
115  /*
116  * The HBA method that determined the above authn_id. This only has
117  * meaning if authn_id is not NULL; otherwise it's undefined.
118  */
121 
122 /*
123  * This is used by the postmaster in its communication with frontends. It
124  * contains all state information needed during this communication before the
125  * backend is run. The Port structure is kept in malloc'd memory and is
126  * still available when a backend is running (see MyProcPort). The data
127  * it points to must also be malloc'd, or else palloc'd in TopMemoryContext,
128  * so that it survives into PostgresMain execution!
129  *
130  * remote_hostname is set if we did a successful reverse lookup of the
131  * client's IP address during connection setup.
132  * remote_hostname_resolv tracks the state of hostname verification:
133  * +1 = remote_hostname is known to resolve to client's IP address
134  * -1 = remote_hostname is known NOT to resolve to client's IP address
135  * 0 = we have not done the forward DNS lookup yet
136  * -2 = there was an error in name resolution
137  * If reverse lookup of the client IP address fails, remote_hostname will be
138  * left NULL while remote_hostname_resolv is set to -2. If reverse lookup
139  * succeeds but forward lookup fails, remote_hostname_resolv is also set to -2
140  * (the case is distinguishable because remote_hostname isn't NULL). In
141  * either of the -2 cases, remote_hostname_errcode saves the lookup return
142  * code for possible later use with gai_strerror.
143  */
144 
145 typedef struct Port
146 {
147  pgsocket sock; /* File descriptor */
148  bool noblock; /* is the socket in non-blocking mode? */
149  ProtocolVersion proto; /* FE/BE protocol version */
150  SockAddr laddr; /* local addr (postmaster) */
151  SockAddr raddr; /* remote addr (client) */
152  char *remote_host; /* name (or ip addr) of remote host */
153  char *remote_hostname; /* name (not ip addr) of remote host, if
154  * available */
155  int remote_hostname_resolv; /* see above */
156  int remote_hostname_errcode; /* see above */
157  char *remote_port; /* text rep of remote port */
158  CAC_state canAcceptConnections; /* postmaster connection status */
159 
160  /*
161  * Information that needs to be saved from the startup packet and passed
162  * into backend execution. "char *" fields are NULL if not set.
163  * guc_options points to a List of alternating option names and values.
164  */
166  char *user_name;
169 
170  /*
171  * The startup packet application name, only used here for the "connection
172  * authorized" log message. We shouldn't use this post-startup, instead
173  * the GUC should be used as application can change it afterward.
174  */
176 
177  /*
178  * Information that needs to be held during the authentication cycle.
179  */
181 
182  /*
183  * TCP keepalive and user timeout settings.
184  *
185  * default values are 0 if AF_UNIX or not yet known; current values are 0
186  * if AF_UNIX or using the default. Also, -1 in a default value means we
187  * were unable to find out the default (getsockopt failed).
188  */
197 
198  /*
199  * GSSAPI structures.
200  */
201 #if defined(ENABLE_GSS) || defined(ENABLE_SSPI)
202 
203  /*
204  * If GSSAPI is supported and used on this connection, store GSSAPI
205  * information. Even when GSSAPI is not compiled in, store a NULL pointer
206  * to keep struct offsets the same (for extension ABI compatibility).
207  */
208  pg_gssinfo *gss;
209 #else
210  void *gss;
211 #endif
212 
213  /*
214  * SSL structures.
215  */
217  char *peer_cn;
218  char *peer_dn;
220 
221  /*
222  * OpenSSL structures. (Keep these last so that the locations of other
223  * fields are the same whether or not you build with SSL enabled.)
224  */
225 #ifdef USE_OPENSSL
226  SSL *ssl;
227  X509 *peer;
228 #endif
230 
231 #ifdef USE_SSL
232 /*
233  * Hardcoded DH parameters, used in ephemeral DH keying. (See also
234  * README.SSL for more details on EDH.)
235  *
236  * This is the 2048-bit DH parameter from RFC 3526. The generation of the
237  * prime is specified in RFC 2412 Appendix E, which also discusses the
238  * design choice of the generator. Note that when loaded with OpenSSL
239  * this causes DH_check() to fail on DH_NOT_SUITABLE_GENERATOR, where
240  * leaking a bit is preferred.
241  */
242 #define FILE_DH2048 \
243 "-----BEGIN DH PARAMETERS-----\n\
244 MIIBCAKCAQEA///////////JD9qiIWjCNMTGYouA3BzRKQJOCIpnzHQCC76mOxOb\n\
245 IlFKCHmONATd75UZs806QxswKwpt8l8UN0/hNW1tUcJF5IW1dmJefsb0TELppjft\n\
246 awv/XLb0Brft7jhr+1qJn6WunyQRfEsf5kkoZlHs5Fs9wgB8uKFjvwWY2kg2HFXT\n\
247 mmkWP6j9JM9fg2VdI9yjrZYcYvNWIIVSu57VKQdwlpZtZww1Tkq8mATxdGwIyhgh\n\
248 fDKQXkYuNs474553LBgOhgObJ4Oi7Aeij7XFXfBvTFLJ3ivL9pVYFxg5lUl86pVq\n\
249 5RXSJhiY+gUQFXKOWoqsqmj//////////wIBAg==\n\
250 -----END DH PARAMETERS-----\n"
251 
252 /*
253  * These functions are implemented by the glue code specific to each
254  * SSL implementation (e.g. be-secure-openssl.c)
255  */
256 
257 /*
258  * Initialize global SSL context.
259  *
260  * If isServerStart is true, report any errors as FATAL (so we don't return).
261  * Otherwise, log errors at LOG level and return -1 to indicate trouble,
262  * preserving the old SSL state if any. Returns 0 if OK.
263  */
264 extern int be_tls_init(bool isServerStart);
265 
266 /*
267  * Destroy global SSL context, if any.
268  */
269 extern void be_tls_destroy(void);
270 
271 /*
272  * Attempt to negotiate SSL connection.
273  */
274 extern int be_tls_open_server(Port *port);
275 
276 /*
277  * Close SSL connection.
278  */
279 extern void be_tls_close(Port *port);
280 
281 /*
282  * Read data from a secure connection.
283  */
284 extern ssize_t be_tls_read(Port *port, void *ptr, size_t len, int *waitfor);
285 
286 /*
287  * Write data to a secure connection.
288  */
289 extern ssize_t be_tls_write(Port *port, void *ptr, size_t len, int *waitfor);
290 
291 /*
292  * Return information about the SSL connection.
293  */
294 extern int be_tls_get_cipher_bits(Port *port);
295 extern const char *be_tls_get_version(Port *port);
296 extern const char *be_tls_get_cipher(Port *port);
297 extern void be_tls_get_peer_subject_name(Port *port, char *ptr, size_t len);
298 extern void be_tls_get_peer_issuer_name(Port *port, char *ptr, size_t len);
299 extern void be_tls_get_peer_serial(Port *port, char *ptr, size_t len);
300 
301 /*
302  * Get the server certificate hash for SCRAM channel binding type
303  * tls-server-end-point.
304  *
305  * The result is a palloc'd hash of the server certificate with its
306  * size, and NULL if there is no certificate available.
307  *
308  * This is not supported with old versions of OpenSSL that don't have
309  * the X509_get_signature_nid() function.
310  */
311 #if defined(USE_OPENSSL) && defined(HAVE_X509_GET_SIGNATURE_NID)
312 #define HAVE_BE_TLS_GET_CERTIFICATE_HASH
313 extern char *be_tls_get_certificate_hash(Port *port, size_t *len);
314 #endif
315 
316 /* init hook for SSL, the default sets the password callback if appropriate */
317 #ifdef USE_OPENSSL
318 typedef void (*openssl_tls_init_hook_typ) (SSL_CTX *context, bool isServerStart);
319 extern PGDLLIMPORT openssl_tls_init_hook_typ openssl_tls_init_hook;
320 #endif
321 
322 #endif /* USE_SSL */
323 
324 #ifdef ENABLE_GSS
325 /*
326  * Return information about the GSSAPI authenticated connection
327  */
328 extern bool be_gssapi_get_auth(Port *port);
329 extern bool be_gssapi_get_enc(Port *port);
330 extern const char *be_gssapi_get_princ(Port *port);
331 
332 /* Read and write to a GSSAPI-encrypted connection. */
333 extern ssize_t be_gssapi_read(Port *port, void *ptr, size_t len);
334 extern ssize_t be_gssapi_write(Port *port, void *ptr, size_t len);
335 #endif /* ENABLE_GSS */
336 
339 
340 /* TCP keepalives configuration. These are no-ops on an AF_UNIX socket. */
341 
342 extern int pq_getkeepalivesidle(Port *port);
343 extern int pq_getkeepalivesinterval(Port *port);
344 extern int pq_getkeepalivescount(Port *port);
345 extern int pq_gettcpusertimeout(Port *port);
346 
347 extern int pq_setkeepalivesidle(int idle, Port *port);
348 extern int pq_setkeepalivesinterval(int interval, Port *port);
349 extern int pq_setkeepalivescount(int count, Port *port);
350 extern int pq_settcpusertimeout(int timeout, Port *port);
351 
352 #endif /* LIBPQ_BE_H */
bool be_gssapi_get_auth(Port *port)
ssize_t be_gssapi_read(Port *port, void *ptr, size_t len)
ssize_t be_gssapi_write(Port *port, void *ptr, size_t len)
bool be_gssapi_get_enc(Port *port)
const char * be_gssapi_get_princ(Port *port)
const char * be_tls_get_version(Port *port)
void be_tls_destroy(void)
int be_tls_init(bool isServerStart)
openssl_tls_init_hook_typ openssl_tls_init_hook
int be_tls_get_cipher_bits(Port *port)
int be_tls_open_server(Port *port)
void be_tls_get_peer_serial(Port *port, char *ptr, size_t len)
void be_tls_close(Port *port)
void be_tls_get_peer_issuer_name(Port *port, char *ptr, size_t len)
ssize_t be_tls_read(Port *port, void *ptr, size_t len, int *waitfor)
ssize_t be_tls_write(Port *port, void *ptr, size_t len, int *waitfor)
const char * be_tls_get_cipher(Port *port)
void be_tls_get_peer_subject_name(Port *port, char *ptr, size_t len)
#define PGDLLIMPORT
Definition: c.h:1252
const char * name
Definition: encode.c:561
struct pg_encoding enc
Definition: encode.c:562
UserAuth
Definition: hba.h:26
static struct @143 value
int pq_setkeepalivesinterval(int interval, Port *port)
Definition: pqcomm.c:1719
PGDLLIMPORT ProtocolVersion FrontendProtocol
Definition: globals.c:28
int pq_getkeepalivescount(Port *port)
Definition: pqcomm.c:1768
int pq_getkeepalivesinterval(Port *port)
Definition: pqcomm.c:1684
int pq_settcpusertimeout(int timeout, Port *port)
Definition: pqcomm.c:1873
CAC_state
Definition: libpq-be.h:62
@ CAC_TOOMANY
Definition: libpq-be.h:68
@ CAC_OK
Definition: libpq-be.h:63
@ CAC_RECOVERY
Definition: libpq-be.h:66
@ CAC_NOTCONSISTENT
Definition: libpq-be.h:67
@ CAC_STARTUP
Definition: libpq-be.h:64
@ CAC_SHUTDOWN
Definition: libpq-be.h:65
int pq_setkeepalivesidle(int idle, Port *port)
Definition: pqcomm.c:1634
int pq_getkeepalivesidle(Port *port)
Definition: pqcomm.c:1599
struct Port Port
PGDLLIMPORT ClientConnectionInfo MyClientConnectionInfo
Definition: miscinit.c:997
struct ClientConnectionInfo ClientConnectionInfo
int pq_gettcpusertimeout(Port *port)
Definition: pqcomm.c:1843
int pq_setkeepalivescount(int count, Port *port)
Definition: pqcomm.c:1798
const void size_t len
static int port
Definition: pg_regress.c:90
int pgsocket
Definition: port.h:29
uint32 ProtocolVersion
Definition: pqcomm.h:87
const char * authn_id
Definition: libpq-be.h:113
UserAuth auth_method
Definition: libpq-be.h:119
Definition: hba.h:95
Definition: pg_list.h:52
Definition: libpq-be.h:146
bool ssl_in_use
Definition: libpq-be.h:216
char * user_name
Definition: libpq-be.h:166
ProtocolVersion proto
Definition: libpq-be.h:149
char * remote_port
Definition: libpq-be.h:157
SockAddr laddr
Definition: libpq-be.h:150
char * remote_hostname
Definition: libpq-be.h:153
int remote_hostname_errcode
Definition: libpq-be.h:156
int default_keepalives_idle
Definition: libpq-be.h:189
int keepalives_idle
Definition: libpq-be.h:193
int keepalives_count
Definition: libpq-be.h:195
void * gss
Definition: libpq-be.h:210
int default_keepalives_interval
Definition: libpq-be.h:190
bool peer_cert_valid
Definition: libpq-be.h:219
char * database_name
Definition: libpq-be.h:165
char * remote_host
Definition: libpq-be.h:152
pgsocket sock
Definition: libpq-be.h:147
HbaLine * hba
Definition: libpq-be.h:180
char * peer_cn
Definition: libpq-be.h:217
int default_keepalives_count
Definition: libpq-be.h:191
char * cmdline_options
Definition: libpq-be.h:167
int keepalives_interval
Definition: libpq-be.h:194
SockAddr raddr
Definition: libpq-be.h:151
int remote_hostname_resolv
Definition: libpq-be.h:155
List * guc_options
Definition: libpq-be.h:168
char * peer_dn
Definition: libpq-be.h:218
bool noblock
Definition: libpq-be.h:148
char * application_name
Definition: libpq-be.h:175
int default_tcp_user_timeout
Definition: libpq-be.h:192
CAC_state canAcceptConnections
Definition: libpq-be.h:158
int tcp_user_timeout
Definition: libpq-be.h:196