DATA = postgres_fdw--1.0.sql postgres_fdw--1.0--1.1.sql postgres_fdw--1.1--1.2.sql
REGRESS = postgres_fdw query_cancel
+TAP_TESTS = 1
ifdef USE_PGXS
PG_CONFIG = pg_config
#include "access/xact.h"
#include "catalog/pg_user_mapping.h"
#include "commands/defrem.h"
+#include "common/base64.h"
#include "funcapi.h"
#include "libpq/libpq-be.h"
#include "libpq/libpq-be-fe-helpers.h"
static void pgfdw_security_check(const char **keywords, const char **values,
UserMapping *user, PGconn *conn);
static bool UserMappingPasswordRequired(UserMapping *user);
+static bool UseScramPassthrough(ForeignServer *server, UserMapping *user);
static bool disconnect_cached_connections(Oid serverid);
static void postgres_fdw_get_connections_internal(FunctionCallInfo fcinfo,
enum pgfdwVersion api_version);
* for application_name, fallback_application_name, client_encoding,
* end marker.
*/
- n = list_length(server->options) + list_length(user->options) + 4;
+ n = list_length(server->options) + list_length(user->options) + 4 + 2;
keywords = (const char **) palloc(n * sizeof(char *));
values = (const char **) palloc(n * sizeof(char *));
values[n] = GetDatabaseEncodingName();
n++;
+ if (MyProcPort->has_scram_keys && UseScramPassthrough(server, user))
+ {
+ int len;
+
+ keywords[n] = "scram_client_key";
+ len = pg_b64_enc_len(sizeof(MyProcPort->scram_ClientKey));
+ /* don't forget the zero-terminator */
+ values[n] = palloc0(len + 1);
+ pg_b64_encode((const char *) MyProcPort->scram_ClientKey,
+ sizeof(MyProcPort->scram_ClientKey),
+ (char *) values[n], len);
+ n++;
+
+ keywords[n] = "scram_server_key";
+ len = pg_b64_enc_len(sizeof(MyProcPort->scram_ServerKey));
+ /* don't forget the zero-terminator */
+ values[n] = palloc0(len + 1);
+ pg_b64_encode((const char *) MyProcPort->scram_ServerKey,
+ sizeof(MyProcPort->scram_ServerKey),
+ (char *) values[n], len);
+ n++;
+ }
+
keywords[n] = values[n] = NULL;
- /* verify the set of connection parameters */
- check_conn_params(keywords, values, user);
+ /*
+ * Verify the set of connection parameters only if scram pass-through
+ * is not being used because the password is not necessary.
+ */
+ if (!(MyProcPort->has_scram_keys && UseScramPassthrough(server, user)))
+ check_conn_params(keywords, values, user);
/* first time, allocate or get the custom wait event */
if (pgfdw_we_connect == 0)
server->servername),
errdetail_internal("%s", pchomp(PQerrorMessage(conn)))));
- /* Perform post-connection security checks */
- pgfdw_security_check(keywords, values, user, conn);
+ /*
+ * Perform post-connection security checks only if scram pass-through
+ * is not being used because the password is not necessary.
+ */
+ if (!(MyProcPort->has_scram_keys && UseScramPassthrough(server, user)))
+ pgfdw_security_check(keywords, values, user, conn);
/* Prepare new session for use */
configure_remote_session(conn);
return true;
}
+static bool
+UseScramPassthrough(ForeignServer *server, UserMapping *user)
+{
+ ListCell *cell;
+
+ foreach(cell, server->options)
+ {
+ DefElem *def = (DefElem *) lfirst(cell);
+
+ if (strcmp(def->defname, "use_scram_passthrough") == 0)
+ return defGetBoolean(def);
+ }
+
+ foreach(cell, user->options)
+ {
+ DefElem *def = (DefElem *) lfirst(cell);
+
+ if (strcmp(def->defname, "use_scram_passthrough") == 0)
+ return defGetBoolean(def);
+ }
+
+ return false;
+}
+
/*
* For non-superusers, insist that the connstr specify a password or that the
* user provided their own GSSAPI delegated credentials. This
ereport(ERROR,
(errcode(ERRCODE_S_R_E_PROHIBITED_SQL_STATEMENT_ATTEMPTED),
errmsg("password or GSSAPI delegated credentials required"),
- errdetail("Non-superusers must delegate GSSAPI credentials or provide a password in the user mapping.")));
+ errdetail("Non-superusers must delegate GSSAPI credentials, provide a password, or enable SCRAM pass-through in user mapping.")));
}
/*
) SERVER loopback_nopw OPTIONS (schema_name 'public', table_name 'ft1');
SELECT 1 FROM ft1_nopw LIMIT 1;
ERROR: password or GSSAPI delegated credentials required
-DETAIL: Non-superusers must delegate GSSAPI credentials or provide a password in the user mapping.
+DETAIL: Non-superusers must delegate GSSAPI credentials, provide a password, or enable SCRAM pass-through in user mapping.
-- If we add a password to the connstr it'll fail, because we don't allow passwords
-- in connstrs only in user mappings.
ALTER SERVER loopback_nopw OPTIONS (ADD password 'dummypw');
-- lacks password_required=false
SELECT 1 FROM ft1_nopw LIMIT 1;
ERROR: password or GSSAPI delegated credentials required
-DETAIL: Non-superusers must delegate GSSAPI credentials or provide a password in the user mapping.
+DETAIL: Non-superusers must delegate GSSAPI credentials, provide a password, or enable SCRAM pass-through in user mapping.
RESET ROLE;
-- The user mapping for public is passwordless and lacks the password_required=false
-- mapping option, but will work because the current user is a superuser.
],
'regress_args': ['--dlpath', meson.build_root() / 'src/test/regress'],
},
+ 'tap': {
+ 'tests': [
+ 't/001_auth_scram.pl',
+ ],
+ },
}
{"analyze_sampling", ForeignServerRelationId, false},
{"analyze_sampling", ForeignTableRelationId, false},
+ {"use_scram_passthrough", ForeignServerRelationId, false},
+ {"use_scram_passthrough", UserMappingRelationId, false},
+
/*
* sslcert and sslkey are in fact libpq options, but we repeat them
* here to allow them to appear in both foreign server context (when
--- /dev/null
+# Copyright (c) 2024-2025, PostgreSQL Global Development Group
+
+# Test SCRAM authentication when opening a new connection with a foreign
+# server.
+#
+# The test is executed by testing the SCRAM authentifcation on a looplback
+# connection on the same server and with different servers.
+
+use strict;
+use warnings FATAL => 'all';
+use PostgreSQL::Test::Utils;
+use PostgreSQL::Test::Cluster;
+use Test::More;
+
+my $hostaddr = '127.0.0.1';
+my $user = "user01";
+
+my $db0 = "db0"; # For node1
+my $db1 = "db1"; # For node1
+my $db2 = "db2"; # For node2
+my $fdw_server = "db1_fdw";
+my $fdw_server2 = "db2_fdw";
+
+my $node1 = PostgreSQL::Test::Cluster->new('node1');
+my $node2 = PostgreSQL::Test::Cluster->new('node2');
+
+$node1->init;
+$node2->init;
+
+$node1->start;
+$node2->start;
+
+# Test setup
+
+$node1->safe_psql('postgres', qq'CREATE USER $user WITH password \'pass\'');
+$node2->safe_psql('postgres', qq'CREATE USER $user WITH password \'pass\'');
+$ENV{PGPASSWORD} = "pass";
+
+$node1->safe_psql('postgres', qq'CREATE DATABASE $db0');
+$node1->safe_psql('postgres', qq'CREATE DATABASE $db1');
+$node2->safe_psql('postgres', qq'CREATE DATABASE $db2');
+
+setup_table($node1, $db1, "t");
+setup_table($node2, $db2, "t2");
+
+$node1->safe_psql($db0, 'CREATE EXTENSION IF NOT EXISTS postgres_fdw');
+setup_fdw_server($node1, $db0, $fdw_server, $node1, $db1);
+setup_fdw_server($node1, $db0, $fdw_server2, $node2, $db2);
+
+setup_user_mapping($node1, $db0, $fdw_server);
+setup_user_mapping($node1, $db0, $fdw_server2);
+
+# Make the user have the same SCRAM key on both servers. Forcing to have the
+# same iteration and salt.
+my $rolpassword = $node1->safe_psql('postgres',
+ qq"SELECT rolpassword FROM pg_authid WHERE rolname = '$user';");
+$node2->safe_psql('postgres', qq"ALTER ROLE $user PASSWORD '$rolpassword'");
+
+setup_pghba($node1);
+setup_pghba($node2);
+
+# End of test setup
+
+test_fdw_auth($node1, $db0, "t", $fdw_server,
+ "SCRAM auth on the same database cluster must succeed");
+test_fdw_auth($node1, $db0, "t2", $fdw_server2,
+ "SCRAM auth on a different database cluster must succeed");
+test_auth($node2, $db2, "t2",
+ "SCRAM auth directly on foreign server should still succeed");
+
+# Helper functions
+
+sub test_auth
+{
+ local $Test::Builder::Level = $Test::Builder::Level + 1;
+
+ my ($node, $db, $tbl, $testname) = @_;
+ my $connstr = $node->connstr($db) . qq' user=$user';
+
+ my $ret = $node->safe_psql(
+ $db,
+ qq'SELECT count(1) FROM $tbl',
+ connstr => $connstr);
+
+ is($ret, '10', $testname);
+}
+
+sub test_fdw_auth
+{
+ local $Test::Builder::Level = $Test::Builder::Level + 1;
+
+ my ($node, $db, $tbl, $fdw, $testname) = @_;
+ my $connstr = $node->connstr($db) . qq' user=$user';
+
+ $node->safe_psql(
+ $db,
+ qq'IMPORT FOREIGN SCHEMA public LIMIT TO ($tbl) FROM SERVER $fdw INTO public;',
+ connstr => $connstr);
+
+ test_auth($node, $db, $tbl, $testname);
+}
+
+sub setup_pghba
+{
+ my ($node) = @_;
+
+ unlink($node->data_dir . '/pg_hba.conf');
+ $node->append_conf(
+ 'pg_hba.conf', qq{
+ local all all scram-sha-256
+ host all all $hostaddr/32 scram-sha-256
+ });
+
+ $node->restart;
+}
+
+sub setup_user_mapping
+{
+ my ($node, $db, $fdw) = @_;
+
+ $node->safe_psql($db,
+ qq'CREATE USER MAPPING FOR $user SERVER $fdw OPTIONS (user \'$user\');'
+ );
+ $node->safe_psql($db, qq'GRANT USAGE ON FOREIGN SERVER $fdw TO $user;');
+ $node->safe_psql($db, qq'GRANT ALL ON SCHEMA public TO $user');
+}
+
+sub setup_fdw_server
+{
+ my ($node, $db, $fdw, $fdw_node, $dbname) = @_;
+ my $host = $fdw_node->host;
+ my $port = $fdw_node->port;
+
+ $node->safe_psql(
+ $db, qq'CREATE SERVER $fdw FOREIGN DATA WRAPPER postgres_fdw options (
+ host \'$host\', port \'$port\', dbname \'$dbname\', use_scram_passthrough \'true\') '
+ );
+}
+
+sub setup_table
+{
+ my ($node, $db, $tbl) = @_;
+
+ $node->safe_psql($db,
+ qq'CREATE TABLE $tbl AS SELECT g, g + 1 FROM generate_series(1,10) g(g)'
+ );
+ $node->safe_psql($db, qq'GRANT USAGE ON SCHEMA public TO $user');
+ $node->safe_psql($db, qq'GRANT SELECT ON $tbl TO $user');
+}
+
+done_testing();
</listitem>
</varlistentry>
+ <varlistentry id="libpq-connect-scram-client-key" xreflabel="scram_client_key">
+ <term><literal>scram_client_key</literal></term>
+ <listitem>
+ <para>
+ The base64-encoded SCRAM client key. This can be used by foreign-data
+ wrappers or similar middleware to enable pass-through SCRAM
+ authentication. See <xref
+ linkend="postgres-fdw-options-connection-management"/> for one such
+ implementation. It is not meant to be specified directly by users or
+ client applications.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="libpq-connect-scram-server-key" xreflabel="scram_server_key">
+ <term><literal>scram_server_key</literal></term>
+ <listitem>
+ <para>
+ The base64-encoded SCRAM server key. This can be used by foreign-data
+ wrappers or similar middleware to enable pass-through SCRAM
+ authentication. See <xref
+ linkend="postgres-fdw-options-connection-management"/> for one such
+ implementation. It is not meant to be specified directly by users or
+ client applications.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="libpq-connect-service" xreflabel="service">
<term><literal>service</literal></term>
<listitem>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><literal>use_scram_passthrough</literal> (<type>boolean</type>)</term>
+ <listitem>
+ <para>
+ This option controls whether <filename>postgres_fdw</filename> will
+ use the SCRAM pass-through authentication to connect to the foreign
+ server. With SCRAM pass-through authentication,
+ <filename>postgres_fdw</filename> uses SCRAM-hashed secrets instead of
+ plain-text user passwords to connect to the remote server. This
+ avoids storing plain-text user passwords in PostgreSQL system
+ catalogs.
+ </para>
+
+ <para>
+ To use SCRAM pass-through authentication:
+ <itemizedlist>
+ <listitem>
+ <para>
+ The remote server must request SCRAM authentication. (If desired,
+ enforce this on the client side (FDW side) with the option
+ <literal>require_auth</literal>.) If another authentication method
+ is requested by the server, then that one will be used normally.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ The remote server can be of any PostgreSQL version that supports
+ SCRAM. Support for <literal>use_scram_passthrough</literal> is
+ only required on the client side (FDW side).
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ The user mapping password is not used. (It could be set to support
+ other authentication methods, but that would arguably violate the
+ point of this feature, which is to avoid storing plain-text
+ passwords.)
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ The server running <filename>postgres_fdw</filename> and the remote
+ server must have identical SCRAM secrets (encrypted passwords) for
+ the user being used on <filename>postgres_fdw</filename> to
+ authenticate on the foreign server (same salt and iterations, not
+ merely the same password).
+ </para>
+
+ <para>
+ As a corollary, if FDW connections to multiple hosts are to be
+ made, for example for partitioned foreign tables/sharding, then all
+ hosts must have identical SCRAM secrets for the users involved.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ The current session on the PostgreSQL instance that makes the
+ outgoing FDW connections also must also use SCRAM authentication
+ for its incoming client connection. (Hence
+ <quote>pass-through</quote>: SCRAM must be used going in and out.)
+ This is a technical requirement of the SCRAM protocol.
+ </para>
+ </listitem>
+ </itemizedlist>
+ </para>
+ </listitem>
+ </varlistentry>
+
</variablelist>
</sect3>
</sect2>
#include "libpq/crypt.h"
#include "libpq/sasl.h"
#include "libpq/scram.h"
+#include "miscadmin.h"
static void scram_get_mechanisms(Port *port, StringInfo buf);
static void *scram_init(Port *port, const char *selected_mech,
int iterations;
char *salt; /* base64-encoded */
+ uint8 ClientKey[SCRAM_MAX_KEY_LEN];
uint8 StoredKey[SCRAM_MAX_KEY_LEN];
uint8 ServerKey[SCRAM_MAX_KEY_LEN];
if (*output)
*outputlen = strlen(*output);
+ if (result == PG_SASL_EXCHANGE_SUCCESS && state->state == SCRAM_AUTH_FINISHED)
+ {
+ memcpy(MyProcPort->scram_ClientKey, state->ClientKey, sizeof(MyProcPort->scram_ClientKey));
+ memcpy(MyProcPort->scram_ServerKey, state->ServerKey, sizeof(MyProcPort->scram_ServerKey));
+ MyProcPort->has_scram_keys = true;
+ }
+
return result;
}
verify_client_proof(scram_state *state)
{
uint8 ClientSignature[SCRAM_MAX_KEY_LEN];
- uint8 ClientKey[SCRAM_MAX_KEY_LEN];
uint8 client_StoredKey[SCRAM_MAX_KEY_LEN];
pg_hmac_ctx *ctx = pg_hmac_create(state->hash_type);
int i;
/* Extract the ClientKey that the client calculated from the proof */
for (i = 0; i < state->key_length; i++)
- ClientKey[i] = state->ClientProof[i] ^ ClientSignature[i];
+ state->ClientKey[i] = state->ClientProof[i] ^ ClientSignature[i];
/* Hash it one more time, and compare with StoredKey */
- if (scram_H(ClientKey, state->hash_type, state->key_length,
+ if (scram_H(state->ClientKey, state->hash_type, state->key_length,
client_StoredKey, &errstr) < 0)
elog(ERROR, "could not hash stored key: %s", errstr);
#ifndef LIBPQ_BE_H
#define LIBPQ_BE_H
+#include "common/scram-common.h"
+
#include <sys/time.h>
#ifdef USE_OPENSSL
#include <openssl/ssl.h>
int keepalives_count;
int tcp_user_timeout;
+ /*
+ * SCRAM structures.
+ */
+ uint8 scram_ClientKey[SCRAM_MAX_KEY_LEN];
+ uint8 scram_ServerKey[SCRAM_MAX_KEY_LEN];
+ bool has_scram_keys; /* true if the above two are valid */
+
/*
* GSSAPI structures.
*/
return NULL;
}
- /* Normalize the password with SASLprep, if possible */
- rc = pg_saslprep(password, &prep_password);
- if (rc == SASLPREP_OOM)
- {
- free(state->sasl_mechanism);
- free(state);
- return NULL;
- }
- if (rc != SASLPREP_SUCCESS)
+ if (password)
{
- prep_password = strdup(password);
- if (!prep_password)
+ /* Normalize the password with SASLprep, if possible */
+ rc = pg_saslprep(password, &prep_password);
+ if (rc == SASLPREP_OOM)
{
free(state->sasl_mechanism);
free(state);
return NULL;
}
+ if (rc != SASLPREP_SUCCESS)
+ {
+ prep_password = strdup(password);
+ if (!prep_password)
+ {
+ free(state->sasl_mechanism);
+ free(state);
+ return NULL;
+ }
+ }
+ state->password = prep_password;
}
- state->password = prep_password;
return state;
}
return false;
}
- /*
- * Calculate SaltedPassword, and store it in 'state' so that we can reuse
- * it later in verify_server_signature.
- */
- if (scram_SaltedPassword(state->password, state->hash_type,
- state->key_length, state->salt, state->saltlen,
- state->iterations, state->SaltedPassword,
- errstr) < 0 ||
- scram_ClientKey(state->SaltedPassword, state->hash_type,
- state->key_length, ClientKey, errstr) < 0 ||
- scram_H(ClientKey, state->hash_type, state->key_length,
- StoredKey, errstr) < 0)
- {
- /* errstr is already filled here */
+ if (state->conn->scram_client_key_binary)
+ {
+ memcpy(ClientKey, state->conn->scram_client_key_binary, SCRAM_MAX_KEY_LEN);
+ }
+ else
+ {
+ /*
+ * Calculate SaltedPassword, and store it in 'state' so that we can
+ * reuse it later in verify_server_signature.
+ */
+ if (scram_SaltedPassword(state->password, state->hash_type,
+ state->key_length, state->salt, state->saltlen,
+ state->iterations, state->SaltedPassword,
+ errstr) < 0 ||
+ scram_ClientKey(state->SaltedPassword, state->hash_type,
+ state->key_length, ClientKey, errstr) < 0)
+ {
+ /* errstr is already filled here */
+ pg_hmac_free(ctx);
+ return false;
+ }
+ }
+
+ if (scram_H(ClientKey, state->hash_type, state->key_length, StoredKey, errstr) < 0)
+ {
pg_hmac_free(ctx);
return false;
}
return false;
}
- if (scram_ServerKey(state->SaltedPassword, state->hash_type,
- state->key_length, ServerKey, errstr) < 0)
+ if (state->conn->scram_server_key_binary)
{
- /* errstr is filled already */
- pg_hmac_free(ctx);
- return false;
+ memcpy(ServerKey, state->conn->scram_server_key_binary, SCRAM_MAX_KEY_LEN);
+ }
+ else
+ {
+ if (scram_ServerKey(state->SaltedPassword, state->hash_type,
+ state->key_length, ServerKey, errstr) < 0)
+ {
+ /* errstr is filled already */
+ pg_hmac_free(ctx);
+ return false;
+ }
}
/* calculate ServerSignature */
* First, select the password to use for the exchange, complaining if
* there isn't one and the selected SASL mechanism needs it.
*/
- if (conn->password_needed)
+ if (conn->password_needed && !conn->scram_client_key_binary)
{
password = conn->connhost[conn->whichhost].password;
if (password == NULL)
#include <time.h>
#include <unistd.h>
+#include "common/base64.h"
#include "common/ip.h"
#include "common/link-canary.h"
#include "common/scram-common.h"
"Load-Balance-Hosts", "", 8, /* sizeof("disable") = 8 */
offsetof(struct pg_conn, load_balance_hosts)},
+ {"scram_client_key", NULL, NULL, NULL, "SCRAM-Client-Key", "D", SCRAM_MAX_KEY_LEN * 2,
+ offsetof(struct pg_conn, scram_client_key)},
+
+ {"scram_server_key", NULL, NULL, NULL, "SCRAM-Server-Key", "D", SCRAM_MAX_KEY_LEN * 2,
+ offsetof(struct pg_conn, scram_server_key)},
+
/* Terminating entry --- MUST BE LAST */
{NULL, NULL, NULL, NULL,
NULL, NULL, 0}
else
conn->target_server_type = SERVER_TYPE_ANY;
+ if (conn->scram_client_key)
+ {
+ int len;
+
+ len = pg_b64_dec_len(strlen(conn->scram_client_key));
+ /* Consider the zero-terminator */
+ if (len != SCRAM_MAX_KEY_LEN + 1)
+ {
+ libpq_append_conn_error(conn, "invalid SCRAM client key length: %d", len);
+ return false;
+ }
+ conn->scram_client_key_len = len;
+ conn->scram_client_key_binary = malloc(len);
+ if (!conn->scram_client_key_binary)
+ goto oom_error;
+ pg_b64_decode(conn->scram_client_key, strlen(conn->scram_client_key),
+ conn->scram_client_key_binary, len);
+ }
+
+ if (conn->scram_server_key)
+ {
+ int len;
+
+ len = pg_b64_dec_len(strlen(conn->scram_server_key));
+ /* Consider the zero-terminator */
+ if (len != SCRAM_MAX_KEY_LEN + 1)
+ {
+ libpq_append_conn_error(conn, "invalid SCRAM server key length: %d", len);
+ return false;
+ }
+ conn->scram_server_key_len = len;
+ conn->scram_server_key_binary = malloc(len);
+ if (!conn->scram_server_key_binary)
+ goto oom_error;
+ pg_b64_decode(conn->scram_server_key, strlen(conn->scram_server_key),
+ conn->scram_server_key_binary, len);
+ }
+
/*
* validate load_balance_hosts option, and set load_balance_type
*/
free(conn->rowBuf);
free(conn->target_session_attrs);
free(conn->load_balance_hosts);
+ free(conn->scram_client_key);
+ free(conn->scram_server_key);
termPQExpBuffer(&conn->errorMessage);
termPQExpBuffer(&conn->workBuffer);
char *target_session_attrs; /* desired session properties */
char *require_auth; /* name of the expected auth method */
char *load_balance_hosts; /* load balance over hosts */
+ char *scram_client_key; /* base64-encoded SCRAM client key */
+ char *scram_server_key; /* base64-encoded SCRAM server key */
bool cancelRequest; /* true if this connection is used to send a
* cancel request, instead of being a normal
AddrInfo *addr; /* the array of addresses for the currently
* tried host */
bool send_appname; /* okay to send application_name? */
+ size_t scram_client_key_len;
+ void *scram_client_key_binary; /* binary SCRAM client key */
+ size_t scram_server_key_len;
+ void *scram_server_key_binary; /* binary SCRAM server key */
/* Miscellaneous stuff */
int be_pid; /* PID of backend --- needed for cancels */
projects / postgresql.git / commitdiff