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fe-gssapi-common.c
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1 /*-------------------------------------------------------------------------
2  *
3  * fe-gssapi-common.c
4  * The front-end (client) GSSAPI common code
5  *
6  * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
7  * Portions Copyright (c) 1994, Regents of the University of California
8  *
9  * IDENTIFICATION
10  * src/interfaces/libpq/fe-gssapi-common.c
11  *-------------------------------------------------------------------------
12  */
13 
14 #include "postgres_fe.h"
15 
16 #include "fe-gssapi-common.h"
17 
18 #include "libpq-int.h"
19 #include "pqexpbuffer.h"
20 
21 /*
22  * Fetch all errors of a specific type and append to "str".
23  * Each error string is preceded by a space.
24  */
25 static void
27 {
28  OM_uint32 lmin_s;
29  gss_buffer_desc lmsg;
30  OM_uint32 msg_ctx = 0;
31 
32  do
33  {
34  if (gss_display_status(&lmin_s, stat, type, GSS_C_NO_OID,
35  &msg_ctx, &lmsg) != GSS_S_COMPLETE)
36  break;
38  appendBinaryPQExpBuffer(str, lmsg.value, lmsg.length);
39  gss_release_buffer(&lmin_s, &lmsg);
40  } while (msg_ctx);
41 }
42 
43 /*
44  * GSSAPI errors contain two parts; put both into conn->errorMessage.
45  */
46 void
47 pg_GSS_error(const char *mprefix, PGconn *conn,
48  OM_uint32 maj_stat, OM_uint32 min_stat)
49 {
50  appendPQExpBuffer(&conn->errorMessage, "%s:", mprefix);
51  pg_GSS_error_int(&conn->errorMessage, maj_stat, GSS_C_GSS_CODE);
53  pg_GSS_error_int(&conn->errorMessage, min_stat, GSS_C_MECH_CODE);
55 }
56 
57 /*
58  * Check if we can acquire credentials at all (and yield them if so).
59  */
60 bool
61 pg_GSS_have_cred_cache(gss_cred_id_t *cred_out)
62 {
63  OM_uint32 major,
64  minor;
65  gss_cred_id_t cred = GSS_C_NO_CREDENTIAL;
66 
67  major = gss_acquire_cred(&minor, GSS_C_NO_NAME, 0, GSS_C_NO_OID_SET,
68  GSS_C_INITIATE, &cred, NULL, NULL);
69  if (major != GSS_S_COMPLETE)
70  {
71  *cred_out = NULL;
72  return false;
73  }
74  *cred_out = cred;
75  return true;
76 }
77 
78 /*
79  * Try to load service name for a connection
80  */
81 int
83 {
84  OM_uint32 maj_stat,
85  min_stat;
86  int maxlen;
87  gss_buffer_desc temp_gbuf;
88  char *host;
89 
90  if (conn->gtarg_nam != NULL)
91  /* Already taken care of - move along */
92  return STATUS_OK;
93 
94  host = PQhost(conn);
95  if (!(host && host[0] != '\0'))
96  {
97  libpq_append_conn_error(conn, "host name must be specified");
98  return STATUS_ERROR;
99  }
100 
101  /*
102  * Import service principal name so the proper ticket can be acquired by
103  * the GSSAPI system.
104  */
105  maxlen = strlen(conn->krbsrvname) + strlen(host) + 2;
106  temp_gbuf.value = (char *) malloc(maxlen);
107  if (!temp_gbuf.value)
108  {
109  libpq_append_conn_error(conn, "out of memory");
110  return STATUS_ERROR;
111  }
112  snprintf(temp_gbuf.value, maxlen, "%s@%s",
113  conn->krbsrvname, host);
114  temp_gbuf.length = strlen(temp_gbuf.value);
115 
116  maj_stat = gss_import_name(&min_stat, &temp_gbuf,
117  GSS_C_NT_HOSTBASED_SERVICE, &conn->gtarg_nam);
118  free(temp_gbuf.value);
119 
120  if (maj_stat != GSS_S_COMPLETE)
121  {
122  pg_GSS_error(libpq_gettext("GSSAPI name import error"),
123  conn,
124  maj_stat, min_stat);
125  return STATUS_ERROR;
126  }
127  return STATUS_OK;
128 }
#define STATUS_OK
Definition: c.h:1159
#define STATUS_ERROR
Definition: c.h:1160
char * PQhost(const PGconn *conn)
Definition: fe-connect.c:6622
void pg_GSS_error(const char *mprefix, PGconn *conn, OM_uint32 maj_stat, OM_uint32 min_stat)
int pg_GSS_load_servicename(PGconn *conn)
static void pg_GSS_error_int(PQExpBuffer str, OM_uint32 stat, int type)
bool pg_GSS_have_cred_cache(gss_cred_id_t *cred_out)
void libpq_append_conn_error(PGconn *conn, const char *fmt,...)
Definition: fe-misc.c:1312
#define free(a)
Definition: header.h:65
#define malloc(a)
Definition: header.h:50
#define libpq_gettext(x)
Definition: libpq-int.h:882
#define snprintf
Definition: port.h:238
void appendPQExpBuffer(PQExpBuffer str, const char *fmt,...)
Definition: pqexpbuffer.c:265
void appendBinaryPQExpBuffer(PQExpBuffer str, const char *data, size_t datalen)
Definition: pqexpbuffer.c:397
void appendPQExpBufferChar(PQExpBuffer str, char ch)
Definition: pqexpbuffer.c:378
PGconn * conn
Definition: streamutil.c:54
PQExpBufferData errorMessage
Definition: libpq-int.h:588
char * krbsrvname
Definition: libpq-int.h:393