1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
|
/*-------------------------------------------------------------------------
*
* be-secure-common.c
*
* common implementation-independent SSL support code
*
* While be-secure.c contains the interfaces that the rest of the
* communications code calls, this file contains support routines that are
* used by the library-specific implementations such as be-secure-openssl.c.
*
* Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* src/backend/libpq/be-secure-common.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include <sys/stat.h>
#include <unistd.h>
#include "common/string.h"
#include "libpq/libpq.h"
#include "storage/fd.h"
/*
* Run ssl_passphrase_command
*
* prompt will be substituted for %p. is_server_start determines the loglevel
* of error messages.
*
* The result will be put in buffer buf, which is of size size. The return
* value is the length of the actual result.
*/
int
run_ssl_passphrase_command(const char *prompt, bool is_server_start, char *buf, int size)
{
int loglevel = is_server_start ? ERROR : LOG;
StringInfoData command;
char *p;
FILE *fh;
int pclose_rc;
size_t len = 0;
Assert(prompt);
Assert(size > 0);
buf[0] = '\0';
initStringInfo(&command);
for (p = ssl_passphrase_command; *p; p++)
{
if (p[0] == '%')
{
switch (p[1])
{
case 'p':
appendStringInfoString(&command, prompt);
p++;
break;
case '%':
appendStringInfoChar(&command, '%');
p++;
break;
default:
appendStringInfoChar(&command, p[0]);
}
}
else
appendStringInfoChar(&command, p[0]);
}
fh = OpenPipeStream(command.data, "r");
if (fh == NULL)
{
ereport(loglevel,
(errcode_for_file_access(),
errmsg("could not execute command \"%s\": %m",
command.data)));
goto error;
}
if (!fgets(buf, size, fh))
{
if (ferror(fh))
{
explicit_bzero(buf, size);
ereport(loglevel,
(errcode_for_file_access(),
errmsg("could not read from command \"%s\": %m",
command.data)));
goto error;
}
}
pclose_rc = ClosePipeStream(fh);
if (pclose_rc == -1)
{
explicit_bzero(buf, size);
ereport(loglevel,
(errcode_for_file_access(),
errmsg("could not close pipe to external command: %m")));
goto error;
}
else if (pclose_rc != 0)
{
explicit_bzero(buf, size);
ereport(loglevel,
(errcode_for_file_access(),
errmsg("command \"%s\" failed",
command.data),
errdetail_internal("%s", wait_result_to_str(pclose_rc))));
goto error;
}
/* strip trailing newline and carriage return */
len = pg_strip_crlf(buf);
error:
pfree(command.data);
return len;
}
/*
* Check permissions for SSL key files.
*/
bool
check_ssl_key_file_permissions(const char *ssl_key_file, bool isServerStart)
{
int loglevel = isServerStart ? FATAL : LOG;
struct stat buf;
if (stat(ssl_key_file, &buf) != 0)
{
ereport(loglevel,
(errcode_for_file_access(),
errmsg("could not access private key file \"%s\": %m",
ssl_key_file)));
return false;
}
/* Key file must be a regular file */
if (!S_ISREG(buf.st_mode))
{
ereport(loglevel,
(errcode(ERRCODE_CONFIG_FILE_ERROR),
errmsg("private key file \"%s\" is not a regular file",
ssl_key_file)));
return false;
}
/*
* Refuse to load key files owned by users other than us or root, and
* require no public access to the key file. If the file is owned by us,
* require mode 0600 or less. If owned by root, require 0640 or less to
* allow read access through either our gid or a supplementary gid that
* allows us to read system-wide certificates.
*
* Note that roughly similar checks are performed in
* src/interfaces/libpq/fe-secure-openssl.c so any changes here may need
* to be made there as well. The environment is different though; this
* code can assume that we're not running as root.
*
* Ideally we would do similar permissions checks on Windows, but it is
* not clear how that would work since Unix-style permissions may not be
* available.
*/
#if !defined(WIN32) && !defined(__CYGWIN__)
if (buf.st_uid != geteuid() && buf.st_uid != 0)
{
ereport(loglevel,
(errcode(ERRCODE_CONFIG_FILE_ERROR),
errmsg("private key file \"%s\" must be owned by the database user or root",
ssl_key_file)));
return false;
}
if ((buf.st_uid == geteuid() && buf.st_mode & (S_IRWXG | S_IRWXO)) ||
(buf.st_uid == 0 && buf.st_mode & (S_IWGRP | S_IXGRP | S_IRWXO)))
{
ereport(loglevel,
(errcode(ERRCODE_CONFIG_FILE_ERROR),
errmsg("private key file \"%s\" has group or world access",
ssl_key_file),
errdetail("File must have permissions u=rw (0600) or less if owned by the database user, or permissions u=rw,g=r (0640) or less if owned by root.")));
return false;
}
#endif
return true;
}
|
