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postgresql/src/backend/libpq/auth.c

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/*-------------------------------------------------------------------------
*
* auth.c
* Routines to handle network authentication
*
* Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/libpq/auth.c,v 1.158 2007/11/15 20:04:38 petere Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include <sys/param.h>
#include <sys/socket.h>
#if defined(HAVE_STRUCT_CMSGCRED) || defined(HAVE_STRUCT_FCRED) || defined(HAVE_STRUCT_SOCKCRED)
#include <sys/uio.h>
#include <sys/ucred.h>
#endif
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include "libpq/auth.h"
#include "libpq/crypt.h"
#include "libpq/ip.h"
#include "libpq/libpq.h"
#include "libpq/pqformat.h"
#include "storage/ipc.h"
static void sendAuthRequest(Port *port, AuthRequest areq);
static void auth_failed(Port *port, int status);
static char *recv_password_packet(Port *port);
static int recv_and_check_password_packet(Port *port);
char *pg_krb_server_keyfile;
char *pg_krb_srvnam;
bool pg_krb_caseins_users;
char *pg_krb_server_hostname = NULL;
char *pg_krb_realm = NULL;
#ifdef USE_PAM
#ifdef HAVE_PAM_PAM_APPL_H
#include <pam/pam_appl.h>
#endif
#ifdef HAVE_SECURITY_PAM_APPL_H
#include <security/pam_appl.h>
#endif
#define PGSQL_PAM_SERVICE "postgresql" /* Service name passed to PAM */
static int CheckPAMAuth(Port *port, char *user, char *password);
static int pam_passwd_conv_proc(int num_msg, const struct pam_message ** msg,
struct pam_response ** resp, void *appdata_ptr);
static struct pam_conv pam_passw_conv = {
&pam_passwd_conv_proc,
NULL
};
static char *pam_passwd = NULL; /* Workaround for Solaris 2.6 brokenness */
static Port *pam_port_cludge; /* Workaround for passing "Port *port" into
* pam_passwd_conv_proc */
#endif /* USE_PAM */
#ifdef USE_LDAP
#ifndef WIN32
/* We use a deprecated function to keep the codepath the same as win32. */
#define LDAP_DEPRECATED 1
#include <ldap.h>
#else
#include <winldap.h>
/* Correct header from the Platform SDK */
typedef
ULONG(*__ldap_start_tls_sA) (
IN PLDAP ExternalHandle,
OUT PULONG ServerReturnValue,
OUT LDAPMessage ** result,
IN PLDAPControlA * ServerControls,
IN PLDAPControlA * ClientControls
);
#endif
static int CheckLDAPAuth(Port *port);
#endif
#ifdef KRB5
/*----------------------------------------------------------------
* MIT Kerberos authentication system - protocol version 5
*----------------------------------------------------------------
*/
#include <krb5.h>
/* Some old versions of Kerberos do not include <com_err.h> in <krb5.h> */
#if !defined(__COM_ERR_H) && !defined(__COM_ERR_H__)
#include <com_err.h>
#endif
/*
* Various krb5 state which is not connection specfic, and a flag to
* indicate whether we have initialised it yet.
*/
static int pg_krb5_initialised;
static krb5_context pg_krb5_context;
static krb5_keytab pg_krb5_keytab;
static krb5_principal pg_krb5_server;
static int
pg_krb5_init(void)
{
krb5_error_code retval;
char *khostname;
if (pg_krb5_initialised)
return STATUS_OK;
retval = krb5_init_context(&pg_krb5_context);
if (retval)
{
ereport(LOG,
(errmsg("Kerberos initialization returned error %d",
retval)));
com_err("postgres", retval, "while initializing krb5");
return STATUS_ERROR;
}
retval = krb5_kt_resolve(pg_krb5_context, pg_krb_server_keyfile, &pg_krb5_keytab);
if (retval)
{
ereport(LOG,
(errmsg("Kerberos keytab resolving returned error %d",
retval)));
com_err("postgres", retval, "while resolving keytab file \"%s\"",
pg_krb_server_keyfile);
krb5_free_context(pg_krb5_context);
return STATUS_ERROR;
}
/*
* If no hostname was specified, pg_krb_server_hostname is already NULL.
* If it's set to blank, force it to NULL.
*/
khostname = pg_krb_server_hostname;
if (khostname && khostname[0] == '\0')
khostname = NULL;
retval = krb5_sname_to_principal(pg_krb5_context,
khostname,
pg_krb_srvnam,
KRB5_NT_SRV_HST,
&pg_krb5_server);
if (retval)
{
ereport(LOG,
(errmsg("Kerberos sname_to_principal(\"%s\", \"%s\") returned error %d",
khostname ? khostname : "server hostname", pg_krb_srvnam, retval)));
com_err("postgres", retval,
"while getting server principal for server \"%s\" for service \"%s\"",
khostname ? khostname : "server hostname", pg_krb_srvnam);
krb5_kt_close(pg_krb5_context, pg_krb5_keytab);
krb5_free_context(pg_krb5_context);
return STATUS_ERROR;
}
pg_krb5_initialised = 1;
return STATUS_OK;
}
/*
* pg_krb5_recvauth -- server routine to receive authentication information
* from the client
*
* We still need to compare the username obtained from the client's setup
* packet to the authenticated name.
*
* We have our own keytab file because postgres is unlikely to run as root,
* and so cannot read the default keytab.
*/
static int
pg_krb5_recvauth(Port *port)
{
krb5_error_code retval;
int ret;
krb5_auth_context auth_context = NULL;
krb5_ticket *ticket;
char *kusername;
char *cp;
if (get_role_line(port->user_name) == NULL)
return STATUS_ERROR;
ret = pg_krb5_init();
if (ret != STATUS_OK)
return ret;
retval = krb5_recvauth(pg_krb5_context, &auth_context,
(krb5_pointer) & port->sock, pg_krb_srvnam,
pg_krb5_server, 0, pg_krb5_keytab, &ticket);
if (retval)
{
ereport(LOG,
(errmsg("Kerberos recvauth returned error %d",
retval)));
com_err("postgres", retval, "from krb5_recvauth");
return STATUS_ERROR;
}
/*
* The "client" structure comes out of the ticket and is therefore
* authenticated. Use it to check the username obtained from the
* postmaster startup packet.
*/
#if defined(HAVE_KRB5_TICKET_ENC_PART2)
retval = krb5_unparse_name(pg_krb5_context,
ticket->enc_part2->client, &kusername);
#elif defined(HAVE_KRB5_TICKET_CLIENT)
retval = krb5_unparse_name(pg_krb5_context,
ticket->client, &kusername);
#else
#error "bogus configuration"
#endif
if (retval)
{
ereport(LOG,
(errmsg("Kerberos unparse_name returned error %d",
retval)));
com_err("postgres", retval, "while unparsing client name");
krb5_free_ticket(pg_krb5_context, ticket);
krb5_auth_con_free(pg_krb5_context, auth_context);
return STATUS_ERROR;
}
cp = strchr(kusername, '@');
if (cp)
{
*cp = '\0';
cp++;
if (pg_krb_realm != NULL && strlen(pg_krb_realm))
{
/* Match realm against configured */
if (pg_krb_caseins_users)
ret = pg_strcasecmp(pg_krb_realm, cp);
else
ret = strcmp(pg_krb_realm, cp);
if (ret)
{
elog(DEBUG2,
"krb5 realm (%s) and configured realm (%s) don't match",
cp, pg_krb_realm);
krb5_free_ticket(pg_krb5_context, ticket);
krb5_auth_con_free(pg_krb5_context, auth_context);
return STATUS_ERROR;
}
}
}
else if (pg_krb_realm && strlen(pg_krb_realm))
{
elog(DEBUG2,
"krb5 did not return realm but realm matching was requested");
krb5_free_ticket(pg_krb5_context, ticket);
krb5_auth_con_free(pg_krb5_context, auth_context);
return STATUS_ERROR;
}
if (pg_krb_caseins_users)
ret = pg_strncasecmp(port->user_name, kusername, SM_DATABASE_USER);
else
ret = strncmp(port->user_name, kusername, SM_DATABASE_USER);
if (ret)
{
ereport(LOG,
(errmsg("unexpected Kerberos user name received from client (received \"%s\", expected \"%s\")",
port->user_name, kusername)));
ret = STATUS_ERROR;
}
else
ret = STATUS_OK;
krb5_free_ticket(pg_krb5_context, ticket);
krb5_auth_con_free(pg_krb5_context, auth_context);
free(kusername);
return ret;
}
#else
static int
pg_krb5_recvauth(Port *port)
{
ereport(LOG,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("Kerberos 5 not implemented on this server")));
return STATUS_ERROR;
}
#endif /* KRB5 */
#ifdef ENABLE_GSS
/*----------------------------------------------------------------
* GSSAPI authentication system
*----------------------------------------------------------------
*/
#if defined(HAVE_GSSAPI_H)
#include <gssapi.h>
#else
#include <gssapi/gssapi.h>
#endif
#if defined(WIN32) && !defined(WIN32_ONLY_COMPILER)
/*
* MIT Kerberos GSSAPI DLL doesn't properly export the symbols for MingW
* that contain the OIDs required. Redefine here, values copied
* from src/athena/auth/krb5/src/lib/gssapi/generic/gssapi_generic.c
*/
static const gss_OID_desc GSS_C_NT_USER_NAME_desc =
{10, (void *)"\x2a\x86\x48\x86\xf7\x12\x01\x02\x01\x02"};
static GSS_DLLIMP gss_OID GSS_C_NT_USER_NAME = &GSS_C_NT_USER_NAME_desc;
#endif
static void
pg_GSS_error(int severity, char *errmsg, OM_uint32 maj_stat, OM_uint32 min_stat)
{
gss_buffer_desc gmsg;
OM_uint32 lmaj_s, lmin_s, msg_ctx;
char msg_major[128],
msg_minor[128];
/* Fetch major status message */
msg_ctx = 0;
lmaj_s = gss_display_status(&lmin_s, maj_stat, GSS_C_GSS_CODE,
GSS_C_NO_OID, &msg_ctx, &gmsg);
strlcpy(msg_major, gmsg.value, sizeof(msg_major));
gss_release_buffer(&lmin_s, &gmsg);
if (msg_ctx)
/* More than one message available.
* XXX: Should we loop and read all messages?
* (same below)
*/
ereport(WARNING,
(errmsg_internal("incomplete GSS error report")));
/* Fetch mechanism minor status message */
msg_ctx = 0;
lmaj_s = gss_display_status(&lmin_s, min_stat, GSS_C_MECH_CODE,
GSS_C_NO_OID, &msg_ctx, &gmsg);
strlcpy(msg_minor, gmsg.value, sizeof(msg_minor));
gss_release_buffer(&lmin_s, &gmsg);
if (msg_ctx)
ereport(WARNING,
(errmsg_internal("incomplete GSS minor error report")));
/* errmsg_internal, since translation of the first part must be
* done before calling this function anyway. */
ereport(severity,
(errmsg_internal("%s", errmsg),
errdetail("%s: %s", msg_major, msg_minor)));
}
static int
pg_GSS_recvauth(Port *port)
{
OM_uint32 maj_stat, min_stat, lmin_s, gflags;
char *kt_path;
int mtype;
int ret;
StringInfoData buf;
gss_buffer_desc gbuf;
if (pg_krb_server_keyfile && strlen(pg_krb_server_keyfile) > 0)
{
/*
* Set default Kerberos keytab file for the Krb5 mechanism.
*
* setenv("KRB5_KTNAME", pg_krb_server_keyfile, 0);
* except setenv() not always available.
*/
if (!getenv("KRB5_KTNAME"))
{
kt_path = palloc(MAXPGPATH + 13);
snprintf(kt_path, MAXPGPATH + 13,
"KRB5_KTNAME=%s", pg_krb_server_keyfile);
putenv(kt_path);
}
}
/*
* We accept any service principal that's present in our
* keytab. This increases interoperability between kerberos
* implementations that see for example case sensitivity
* differently, while not really opening up any vector
* of attack.
*/
port->gss->cred = GSS_C_NO_CREDENTIAL;
/*
* Initialize sequence with an empty context
*/
port->gss->ctx = GSS_C_NO_CONTEXT;
/*
* Loop through GSSAPI message exchange. This exchange can consist
* of multiple messags sent in both directions. First message is always
* from the client. All messages from client to server are password
* packets (type 'p').
*/
do
{
mtype = pq_getbyte();
if (mtype != 'p')
{
/* Only log error if client didn't disconnect. */
if (mtype != EOF)
ereport(COMMERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("expected GSS response, got message type %d",
mtype)));
return STATUS_ERROR;
}
/* Get the actual GSS token */
initStringInfo(&buf);
if (pq_getmessage(&buf, 2000))
{
/* EOF - pq_getmessage already logged error */
pfree(buf.data);
return STATUS_ERROR;
}
/* Map to GSSAPI style buffer */
gbuf.length = buf.len;
gbuf.value = buf.data;
elog(DEBUG4, "Processing received GSS token of length %u",
(unsigned int) gbuf.length);
maj_stat = gss_accept_sec_context(
&min_stat,
&port->gss->ctx,
port->gss->cred,
&gbuf,
GSS_C_NO_CHANNEL_BINDINGS,
&port->gss->name,
NULL,
&port->gss->outbuf,
&gflags,
NULL,
NULL);
/* gbuf no longer used */
pfree(buf.data);
elog(DEBUG5, "gss_accept_sec_context major: %d, "
"minor: %d, outlen: %u, outflags: %x",
maj_stat, min_stat,
(unsigned int) port->gss->outbuf.length, gflags);
if (port->gss->outbuf.length != 0)
{
/*
* Negotiation generated data to be sent to the client.
*/
OM_uint32 lmin_s;
elog(DEBUG4, "sending GSS response token of length %u",
(unsigned int) port->gss->outbuf.length);
sendAuthRequest(port, AUTH_REQ_GSS_CONT);
gss_release_buffer(&lmin_s, &port->gss->outbuf);
}
if (maj_stat != GSS_S_COMPLETE && maj_stat != GSS_S_CONTINUE_NEEDED)
{
OM_uint32 lmin_s;
gss_delete_sec_context(&lmin_s, &port->gss->ctx, GSS_C_NO_BUFFER);
pg_GSS_error(ERROR,
gettext_noop("accepting GSS security context failed"),
maj_stat, min_stat);
}
if (maj_stat == GSS_S_CONTINUE_NEEDED)
elog(DEBUG4, "GSS continue needed");
} while (maj_stat == GSS_S_CONTINUE_NEEDED);
if (port->gss->cred != GSS_C_NO_CREDENTIAL)
{
/*
* Release service principal credentials
*/
gss_release_cred(&min_stat, &port->gss->cred);
}
/*
* GSS_S_COMPLETE indicates that authentication is now complete.
*
* Get the name of the user that authenticated, and compare it to the
* pg username that was specified for the connection.
*/
maj_stat = gss_display_name(&min_stat, port->gss->name, &gbuf, NULL);
if (maj_stat != GSS_S_COMPLETE)
pg_GSS_error(ERROR,
gettext_noop("retreiving GSS user name failed"),
maj_stat, min_stat);
/*
* Split the username at the realm separator
*/
if (strchr(gbuf.value, '@'))
{
char *cp = strchr(gbuf.value, '@');
*cp = '\0';
cp++;
if (pg_krb_realm != NULL && strlen(pg_krb_realm))
{
/*
* Match the realm part of the name first
*/
if (pg_krb_caseins_users)
ret = pg_strcasecmp(pg_krb_realm, cp);
else
ret = strcmp(pg_krb_realm, cp);
if (ret)
{
/* GSS realm does not match */
elog(DEBUG2,
"GSSAPI realm (%s) and configured realm (%s) don't match",
cp, pg_krb_realm);
gss_release_buffer(&lmin_s, &gbuf);
return STATUS_ERROR;
}
}
}
else if (pg_krb_realm && strlen(pg_krb_realm))
{
elog(DEBUG2,
"GSSAPI did not return realm but realm matching was requested");
gss_release_buffer(&lmin_s, &gbuf);
return STATUS_ERROR;
}
if (pg_krb_caseins_users)
ret = pg_strcasecmp(port->user_name, gbuf.value);
else
ret = strcmp(port->user_name, gbuf.value);
if (ret)
{
/* GSS name and PGUSER are not equivalent */
elog(DEBUG2,
"provided username (%s) and GSSAPI username (%s) don't match",
port->user_name, (char *)gbuf.value);
gss_release_buffer(&lmin_s, &gbuf);
return STATUS_ERROR;
}
gss_release_buffer(&lmin_s, &gbuf);
return STATUS_OK;
}
#else /* no ENABLE_GSS */
static int
pg_GSS_recvauth(Port *port)
{
ereport(LOG,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("GSSAPI not implemented on this server")));
return STATUS_ERROR;
}
#endif /* ENABLE_GSS */
#ifdef ENABLE_SSPI
static void
pg_SSPI_error(int severity, char *errmsg, SECURITY_STATUS r)
{
char sysmsg[256];
if (FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, NULL, r, 0, sysmsg, sizeof(sysmsg), NULL) == 0)
ereport(severity,
(errmsg_internal("%s", errmsg),
errdetail("sspi error %x", (unsigned int)r)));
else
ereport(severity,
(errmsg_internal("%s", errmsg),
errdetail("%s (%x)", sysmsg, (unsigned int)r)));
}
typedef SECURITY_STATUS
(WINAPI * QUERY_SECURITY_CONTEXT_TOKEN_FN)(
PCtxtHandle, void **);
static int
pg_SSPI_recvauth(Port *port)
{
int mtype;
StringInfoData buf;
SECURITY_STATUS r;
CredHandle sspicred;
CtxtHandle *sspictx = NULL,
newctx;
TimeStamp expiry;
ULONG contextattr;
SecBufferDesc inbuf;
SecBufferDesc outbuf;
SecBuffer OutBuffers[1];
SecBuffer InBuffers[1];
HANDLE token;
TOKEN_USER *tokenuser;
DWORD retlen;
char accountname[MAXPGPATH];
char domainname[MAXPGPATH];
DWORD accountnamesize = sizeof(accountname);
DWORD domainnamesize = sizeof(domainname);
SID_NAME_USE accountnameuse;
HMODULE secur32;
QUERY_SECURITY_CONTEXT_TOKEN_FN _QuerySecurityContextToken;
/*
* Acquire a handle to the server credentials.
*/
r = AcquireCredentialsHandle(NULL,
"negotiate",
SECPKG_CRED_INBOUND,
NULL,
NULL,
NULL,
NULL,
&sspicred,
&expiry);
if (r != SEC_E_OK)
pg_SSPI_error(ERROR,
gettext_noop("could not acquire SSPI credentials handle"), r);
/*
* Loop through SSPI message exchange. This exchange can consist
* of multiple messags sent in both directions. First message is always
* from the client. All messages from client to server are password
* packets (type 'p').
*/
do
{
mtype = pq_getbyte();
if (mtype != 'p')
{
/* Only log error if client didn't disconnect. */
if (mtype != EOF)
ereport(COMMERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("expected SSPI response, got message type %d",
mtype)));
return STATUS_ERROR;
}
/* Get the actual SSPI token */
initStringInfo(&buf);
if (pq_getmessage(&buf, 2000))
{
/* EOF - pq_getmessage already logged error */
pfree(buf.data);
return STATUS_ERROR;
}
/* Map to SSPI style buffer */
inbuf.ulVersion = SECBUFFER_VERSION;
inbuf.cBuffers = 1;
inbuf.pBuffers = InBuffers;
InBuffers[0].pvBuffer = buf.data;
InBuffers[0].cbBuffer = buf.len;
InBuffers[0].BufferType = SECBUFFER_TOKEN;
/* Prepare output buffer */
OutBuffers[0].pvBuffer = NULL;
OutBuffers[0].BufferType = SECBUFFER_TOKEN;
OutBuffers[0].cbBuffer = 0;
outbuf.cBuffers = 1;
outbuf.pBuffers = OutBuffers;
outbuf.ulVersion = SECBUFFER_VERSION;
elog(DEBUG4, "Processing received SSPI token of length %u",
(unsigned int) buf.len);
r = AcceptSecurityContext(&sspicred,
sspictx,
&inbuf,
ASC_REQ_ALLOCATE_MEMORY,
SECURITY_NETWORK_DREP,
&newctx,
&outbuf,
&contextattr,
NULL);
/* input buffer no longer used */
pfree(buf.data);
if (outbuf.cBuffers > 0 && outbuf.pBuffers[0].cbBuffer > 0)
{
/*
* Negotiation generated data to be sent to the client.
*/
elog(DEBUG4, "sending SSPI response token of length %u",
(unsigned int) outbuf.pBuffers[0].cbBuffer);
port->gss->outbuf.length = outbuf.pBuffers[0].cbBuffer;
port->gss->outbuf.value = outbuf.pBuffers[0].pvBuffer;
sendAuthRequest(port, AUTH_REQ_GSS_CONT);
FreeContextBuffer(outbuf.pBuffers[0].pvBuffer);
}
if (r != SEC_E_OK && r != SEC_I_CONTINUE_NEEDED)
{
if (sspictx != NULL)
{
DeleteSecurityContext(sspictx);
free(sspictx);
}
FreeCredentialsHandle(&sspicred);
pg_SSPI_error(ERROR,
gettext_noop("could not accept SSPI security context"), r);
}
if (sspictx == NULL)
{
sspictx = malloc(sizeof(CtxtHandle));
if (sspictx == NULL)
ereport(ERROR,
(errmsg("out of memory")));
memcpy(sspictx, &newctx, sizeof(CtxtHandle));
}
if (r == SEC_I_CONTINUE_NEEDED)
elog(DEBUG4, "SSPI continue needed");
} while (r == SEC_I_CONTINUE_NEEDED);
/*
* Release service principal credentials
*/
FreeCredentialsHandle(&sspicred);
/*
* SEC_E_OK indicates that authentication is now complete.
*
* Get the name of the user that authenticated, and compare it to the
* pg username that was specified for the connection.
*
* MingW is missing the export for QuerySecurityContextToken in
* the secur32 library, so we have to load it dynamically.
*/
secur32 = LoadLibrary("SECUR32.DLL");
if (secur32 == NULL)
ereport(ERROR,
(errmsg_internal("could not load secur32.dll: %d",
(int)GetLastError())));
_QuerySecurityContextToken = (QUERY_SECURITY_CONTEXT_TOKEN_FN)
GetProcAddress(secur32, "QuerySecurityContextToken");
if (_QuerySecurityContextToken == NULL)
{
FreeLibrary(secur32);
ereport(ERROR,
(errmsg_internal("could not locate QuerySecurityContextToken in secur32.dll: %d",
(int)GetLastError())));
}
r = (_QuerySecurityContextToken)(sspictx, &token);
if (r != SEC_E_OK)
{
FreeLibrary(secur32);
pg_SSPI_error(ERROR,
gettext_noop("could not get security token from context"), r);
}
FreeLibrary(secur32);
/*
* No longer need the security context, everything from here on uses the
* token instead.
*/
DeleteSecurityContext(sspictx);
free(sspictx);
if (!GetTokenInformation(token, TokenUser, NULL, 0, &retlen) && GetLastError() != 122)
ereport(ERROR,
(errmsg_internal("could not get token user size: error code %d",
(int) GetLastError())));
tokenuser = malloc(retlen);
if (tokenuser == NULL)
ereport(ERROR,
(errmsg("out of memory")));
if (!GetTokenInformation(token, TokenUser, tokenuser, retlen, &retlen))
ereport(ERROR,
(errmsg_internal("could not get user token: error code %d",
(int) GetLastError())));
if (!LookupAccountSid(NULL, tokenuser->User.Sid, accountname, &accountnamesize,
domainname, &domainnamesize, &accountnameuse))
ereport(ERROR,
(errmsg_internal("could not lookup acconut sid: error code %d",
(int) GetLastError())));
free(tokenuser);
/*
* Compare realm/domain if requested. In SSPI, always compare case insensitive.
*/
if (pg_krb_realm && strlen(pg_krb_realm))
{
if (pg_strcasecmp(pg_krb_realm, domainname))
{
elog(DEBUG2,
"SSPI domain (%s) and configured domain (%s) don't match",
domainname, pg_krb_realm);
return STATUS_ERROR;
}
}
/*
* We have the username (without domain/realm) in accountname, compare
* to the supplied value. In SSPI, always compare case insensitive.
*/
if (pg_strcasecmp(port->user_name, accountname))
{
/* GSS name and PGUSER are not equivalent */
elog(DEBUG2,
"provided username (%s) and SSPI username (%s) don't match",
port->user_name, accountname);
return STATUS_ERROR;
}
return STATUS_OK;
}
#else /* no ENABLE_SSPI */
static int
pg_SSPI_recvauth(Port *port)
{
ereport(LOG,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("SSPI not implemented on this server")));
return STATUS_ERROR;
}
#endif /* ENABLE_SSPI */
/*
* Tell the user the authentication failed, but not (much about) why.
*
* There is a tradeoff here between security concerns and making life
* unnecessarily difficult for legitimate users. We would not, for example,
* want to report the password we were expecting to receive...
* But it seems useful to report the username and authorization method
* in use, and these are items that must be presumed known to an attacker
* anyway.
* Note that many sorts of failure report additional information in the
* postmaster log, which we hope is only readable by good guys.
*/
static void
auth_failed(Port *port, int status)
{
const char *errstr;
/*
* If we failed due to EOF from client, just quit; there's no point in
* trying to send a message to the client, and not much point in logging
* the failure in the postmaster log. (Logging the failure might be
* desirable, were it not for the fact that libpq closes the connection
* unceremoniously if challenged for a password when it hasn't got one to
* send. We'll get a useless log entry for every psql connection under
* password auth, even if it's perfectly successful, if we log STATUS_EOF
* events.)
*/
if (status == STATUS_EOF)
proc_exit(0);
switch (port->auth_method)
{
case uaReject:
errstr = gettext_noop("authentication failed for user \"%s\": host rejected");
break;
case uaKrb5:
errstr = gettext_noop("Kerberos 5 authentication failed for user \"%s\"");
break;
case uaGSS:
errstr = gettext_noop("GSSAPI authentication failed for user \"%s\"");
break;
case uaSSPI:
errstr = gettext_noop("SSPI authentication failed for user \"%s\"");
break;
case uaTrust:
errstr = gettext_noop("\"trust\" authentication failed for user \"%s\"");
break;
case uaIdent:
errstr = gettext_noop("Ident authentication failed for user \"%s\"");
break;
case uaMD5:
case uaCrypt:
case uaPassword:
errstr = gettext_noop("password authentication failed for user \"%s\"");
break;
#ifdef USE_PAM
case uaPAM:
errstr = gettext_noop("PAM authentication failed for user \"%s\"");
break;
#endif /* USE_PAM */
#ifdef USE_LDAP
case uaLDAP:
errstr = gettext_noop("LDAP authentication failed for user \"%s\"");
break;
#endif /* USE_LDAP */
default:
errstr = gettext_noop("authentication failed for user \"%s\": invalid authentication method");
break;
}
ereport(FATAL,
(errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
errmsg(errstr, port->user_name)));
/* doesn't return */
}
/*
* Client authentication starts here. If there is an error, this
* function does not return and the backend process is terminated.
*/
void
ClientAuthentication(Port *port)
{
int status = STATUS_ERROR;
/*
* Get the authentication method to use for this frontend/database
* combination. Note: a failure return indicates a problem with the hba
* config file, not with the request. hba.c should have dropped an error
* message into the postmaster logfile if it failed.
*/
if (hba_getauthmethod(port) != STATUS_OK)
ereport(FATAL,
(errcode(ERRCODE_CONFIG_FILE_ERROR),
errmsg("missing or erroneous pg_hba.conf file"),
errhint("See server log for details.")));
switch (port->auth_method)
{
case uaReject:
/*
* This could have come from an explicit "reject" entry in
* pg_hba.conf, but more likely it means there was no matching
* entry. Take pity on the poor user and issue a helpful error
* message. NOTE: this is not a security breach, because all the
* info reported here is known at the frontend and must be assumed
* known to bad guys. We're merely helping out the less clueful
* good guys.
*/
{
char hostinfo[NI_MAXHOST];
pg_getnameinfo_all(&port->raddr.addr, port->raddr.salen,
hostinfo, sizeof(hostinfo),
NULL, 0,
NI_NUMERICHOST);
#ifdef USE_SSL
ereport(FATAL,
(errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
errmsg("no pg_hba.conf entry for host \"%s\", user \"%s\", database \"%s\", %s",
hostinfo, port->user_name, port->database_name,
port->ssl ? _("SSL on") : _("SSL off"))));
#else
ereport(FATAL,
(errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
errmsg("no pg_hba.conf entry for host \"%s\", user \"%s\", database \"%s\"",
hostinfo, port->user_name, port->database_name)));
#endif
break;
}
case uaKrb5:
sendAuthRequest(port, AUTH_REQ_KRB5);
status = pg_krb5_recvauth(port);
break;
case uaGSS:
sendAuthRequest(port, AUTH_REQ_GSS);
status = pg_GSS_recvauth(port);
break;
case uaSSPI:
sendAuthRequest(port, AUTH_REQ_SSPI);
status = pg_SSPI_recvauth(port);
break;
case uaIdent:
/*
* If we are doing ident on unix-domain sockets, use SCM_CREDS
* only if it is defined and SO_PEERCRED isn't.
*/
#if !defined(HAVE_GETPEEREID) && !defined(SO_PEERCRED) && \
(defined(HAVE_STRUCT_CMSGCRED) || defined(HAVE_STRUCT_FCRED) || \
(defined(HAVE_STRUCT_SOCKCRED) && defined(LOCAL_CREDS)))
if (port->raddr.addr.ss_family == AF_UNIX)
{
#if defined(HAVE_STRUCT_FCRED) || defined(HAVE_STRUCT_SOCKCRED)
/*
* Receive credentials on next message receipt, BSD/OS,
* NetBSD. We need to set this before the client sends the
* next packet.
*/
int on = 1;
if (setsockopt(port->sock, 0, LOCAL_CREDS, &on, sizeof(on)) < 0)
ereport(FATAL,
(errcode_for_socket_access(),
errmsg("could not enable credential reception: %m")));
#endif
sendAuthRequest(port, AUTH_REQ_SCM_CREDS);
}
#endif
status = authident(port);
break;
case uaMD5:
sendAuthRequest(port, AUTH_REQ_MD5);
status = recv_and_check_password_packet(port);
break;
case uaCrypt:
sendAuthRequest(port, AUTH_REQ_CRYPT);
status = recv_and_check_password_packet(port);
break;
case uaPassword:
sendAuthRequest(port, AUTH_REQ_PASSWORD);
status = recv_and_check_password_packet(port);
break;
#ifdef USE_PAM
case uaPAM:
pam_port_cludge = port;
status = CheckPAMAuth(port, port->user_name, "");
break;
#endif /* USE_PAM */
#ifdef USE_LDAP
case uaLDAP:
status = CheckLDAPAuth(port);
break;
#endif
case uaTrust:
status = STATUS_OK;
break;
}
if (status == STATUS_OK)
sendAuthRequest(port, AUTH_REQ_OK);
else
auth_failed(port, status);
}
/*
* Send an authentication request packet to the frontend.
*/
static void
sendAuthRequest(Port *port, AuthRequest areq)
{
StringInfoData buf;
pq_beginmessage(&buf, 'R');
pq_sendint(&buf, (int32) areq, sizeof(int32));
/* Add the salt for encrypted passwords. */
if (areq == AUTH_REQ_MD5)
pq_sendbytes(&buf, port->md5Salt, 4);
else if (areq == AUTH_REQ_CRYPT)
pq_sendbytes(&buf, port->cryptSalt, 2);
#if defined(ENABLE_GSS) || defined(ENABLE_SSPI)
/* Add the authentication data for the next step of
* the GSSAPI or SSPI negotiation. */
else if (areq == AUTH_REQ_GSS_CONT)
{
if (port->gss->outbuf.length > 0)
{
elog(DEBUG4, "sending GSS token of length %u",
(unsigned int) port->gss->outbuf.length);
pq_sendbytes(&buf, port->gss->outbuf.value, port->gss->outbuf.length);
}
}
#endif
pq_endmessage(&buf);
/*
* Flush message so client will see it, except for AUTH_REQ_OK, which need
* not be sent until we are ready for queries.
*/
if (areq != AUTH_REQ_OK)
pq_flush();
}
#ifdef USE_PAM
/*
* PAM conversation function
*/
static int
pam_passwd_conv_proc(int num_msg, const struct pam_message ** msg,
struct pam_response ** resp, void *appdata_ptr)
{
if (num_msg != 1 || msg[0]->msg_style != PAM_PROMPT_ECHO_OFF)
{
switch (msg[0]->msg_style)
{
case PAM_ERROR_MSG:
ereport(LOG,
(errmsg("error from underlying PAM layer: %s",
msg[0]->msg)));
return PAM_CONV_ERR;
default:
ereport(LOG,
(errmsg("unsupported PAM conversation %d/%s",
msg[0]->msg_style, msg[0]->msg)));
return PAM_CONV_ERR;
}
}
if (!appdata_ptr)
{
/*
* Workaround for Solaris 2.6 where the PAM library is broken and does
* not pass appdata_ptr to the conversation routine
*/
appdata_ptr = pam_passwd;
}
/*
* Password wasn't passed to PAM the first time around - let's go ask the
* client to send a password, which we then stuff into PAM.
*/
if (strlen(appdata_ptr) == 0)
{
char *passwd;
sendAuthRequest(pam_port_cludge, AUTH_REQ_PASSWORD);
passwd = recv_password_packet(pam_port_cludge);
if (passwd == NULL)
return PAM_CONV_ERR; /* client didn't want to send password */
if (strlen(passwd) == 0)
{
ereport(LOG,
(errmsg("empty password returned by client")));
return PAM_CONV_ERR;
}
appdata_ptr = passwd;
}
/*
* Explicitly not using palloc here - PAM will free this memory in
* pam_end()
*/
*resp = calloc(num_msg, sizeof(struct pam_response));
if (!*resp)
{
ereport(LOG,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of memory")));
return PAM_CONV_ERR;
}
(*resp)[0].resp = strdup((char *) appdata_ptr);
(*resp)[0].resp_retcode = 0;
return ((*resp)[0].resp ? PAM_SUCCESS : PAM_CONV_ERR);
}
/*
* Check authentication against PAM.
*/
static int
CheckPAMAuth(Port *port, char *user, char *password)
{
int retval;
pam_handle_t *pamh = NULL;
/*
* Apparently, Solaris 2.6 is broken, and needs ugly static variable
* workaround
*/
pam_passwd = password;
/*
* Set the application data portion of the conversation struct This is
* later used inside the PAM conversation to pass the password to the
* authentication module.
*/
pam_passw_conv.appdata_ptr = (char *) password; /* from password above,
* not allocated */
/* Optionally, one can set the service name in pg_hba.conf */
if (port->auth_arg && port->auth_arg[0] != '\0')
retval = pam_start(port->auth_arg, "pgsql@",
&pam_passw_conv, &pamh);
else
retval = pam_start(PGSQL_PAM_SERVICE, "pgsql@",
&pam_passw_conv, &pamh);
if (retval != PAM_SUCCESS)
{
ereport(LOG,
(errmsg("could not create PAM authenticator: %s",
pam_strerror(pamh, retval))));
pam_passwd = NULL; /* Unset pam_passwd */
return STATUS_ERROR;
}
retval = pam_set_item(pamh, PAM_USER, user);
if (retval != PAM_SUCCESS)
{
ereport(LOG,
(errmsg("pam_set_item(PAM_USER) failed: %s",
pam_strerror(pamh, retval))));
pam_passwd = NULL; /* Unset pam_passwd */
return STATUS_ERROR;
}
retval = pam_set_item(pamh, PAM_CONV, &pam_passw_conv);
if (retval != PAM_SUCCESS)
{
ereport(LOG,
(errmsg("pam_set_item(PAM_CONV) failed: %s",
pam_strerror(pamh, retval))));
pam_passwd = NULL; /* Unset pam_passwd */
return STATUS_ERROR;
}
retval = pam_authenticate(pamh, 0);
if (retval != PAM_SUCCESS)
{
ereport(LOG,
(errmsg("pam_authenticate failed: %s",
pam_strerror(pamh, retval))));
pam_passwd = NULL; /* Unset pam_passwd */
return STATUS_ERROR;
}
retval = pam_acct_mgmt(pamh, 0);
if (retval != PAM_SUCCESS)
{
ereport(LOG,
(errmsg("pam_acct_mgmt failed: %s",
pam_strerror(pamh, retval))));
pam_passwd = NULL; /* Unset pam_passwd */
return STATUS_ERROR;
}
retval = pam_end(pamh, retval);
if (retval != PAM_SUCCESS)
{
ereport(LOG,
(errmsg("could not release PAM authenticator: %s",
pam_strerror(pamh, retval))));
}
pam_passwd = NULL; /* Unset pam_passwd */
return (retval == PAM_SUCCESS ? STATUS_OK : STATUS_ERROR);
}
#endif /* USE_PAM */
#ifdef USE_LDAP
static int
CheckLDAPAuth(Port *port)
{
char *passwd;
char server[128];
char basedn[128];
char prefix[128];
char suffix[128];
LDAP *ldap;
bool ssl = false;
int r;
int ldapversion = LDAP_VERSION3;
int ldapport = LDAP_PORT;
char fulluser[NAMEDATALEN + 256 + 1];
if (!port->auth_arg || port->auth_arg[0] == '\0')
{
ereport(LOG,
(errmsg("LDAP configuration URL not specified")));
return STATUS_ERROR;
}
/*
* Crack the LDAP url. We do a very trivial parse..
* ldap[s]://<server>[:<port>]/<basedn>[;prefix[;suffix]]
*/
server[0] = '\0';
basedn[0] = '\0';
prefix[0] = '\0';
suffix[0] = '\0';
/* ldap, including port number */
r = sscanf(port->auth_arg,
"ldap://%127[^:]:%d/%127[^;];%127[^;];%127s",
server, &ldapport, basedn, prefix, suffix);
if (r < 3)
{
/* ldaps, including port number */
r = sscanf(port->auth_arg,
"ldaps://%127[^:]:%d/%127[^;];%127[^;];%127s",
server, &ldapport, basedn, prefix, suffix);
if (r >= 3)
ssl = true;
}
if (r < 3)
{
/* ldap, no port number */
r = sscanf(port->auth_arg,
"ldap://%127[^/]/%127[^;];%127[^;];%127s",
server, basedn, prefix, suffix);
}
if (r < 2)
{
/* ldaps, no port number */
r = sscanf(port->auth_arg,
"ldaps://%127[^/]/%127[^;];%127[^;];%127s",
server, basedn, prefix, suffix);
if (r >= 2)
ssl = true;
}
if (r < 2)
{
ereport(LOG,
(errmsg("invalid LDAP URL: \"%s\"",
port->auth_arg)));
return STATUS_ERROR;
}
sendAuthRequest(port, AUTH_REQ_PASSWORD);
passwd = recv_password_packet(port);
if (passwd == NULL)
return STATUS_EOF; /* client wouldn't send password */
ldap = ldap_init(server, ldapport);
if (!ldap)
{
#ifndef WIN32
ereport(LOG,
(errmsg("could not initialize LDAP: error code %d",
errno)));
#else
ereport(LOG,
(errmsg("could not initialize LDAP: error code %d",
(int) LdapGetLastError())));
#endif
return STATUS_ERROR;
}
if ((r = ldap_set_option(ldap, LDAP_OPT_PROTOCOL_VERSION, &ldapversion)) != LDAP_SUCCESS)
{
ldap_unbind(ldap);
ereport(LOG,
(errmsg("could not set LDAP protocol version: error code %d", r)));
return STATUS_ERROR;
}
if (ssl)
{
#ifndef WIN32
if ((r = ldap_start_tls_s(ldap, NULL, NULL)) != LDAP_SUCCESS)
#else
static __ldap_start_tls_sA _ldap_start_tls_sA = NULL;
if (_ldap_start_tls_sA == NULL)
{
/*
* Need to load this function dynamically because it does not
* exist on Windows 2000, and causes a load error for the whole
* exe if referenced.
*/
HANDLE ldaphandle;
ldaphandle = LoadLibrary("WLDAP32.DLL");
if (ldaphandle == NULL)
{
/*
* should never happen since we import other files from
* wldap32, but check anyway
*/
ldap_unbind(ldap);
ereport(LOG,
(errmsg("could not load wldap32.dll")));
return STATUS_ERROR;
}
_ldap_start_tls_sA = (__ldap_start_tls_sA) GetProcAddress(ldaphandle, "ldap_start_tls_sA");
if (_ldap_start_tls_sA == NULL)
{
ldap_unbind(ldap);
ereport(LOG,
(errmsg("could not load function _ldap_start_tls_sA in wldap32.dll"),
errdetail("LDAP over SSL is not supported on this platform.")));
return STATUS_ERROR;
}
/*
* Leak LDAP handle on purpose, because we need the library to stay
* open. This is ok because it will only ever be leaked once per
* process and is automatically cleaned up on process exit.
*/
}
if ((r = _ldap_start_tls_sA(ldap, NULL, NULL, NULL, NULL)) != LDAP_SUCCESS)
#endif
{
ldap_unbind(ldap);
ereport(LOG,
(errmsg("could not start LDAP TLS session: error code %d", r)));
return STATUS_ERROR;
}
}
snprintf(fulluser, sizeof(fulluser), "%s%s%s",
prefix, port->user_name, suffix);
fulluser[sizeof(fulluser) - 1] = '\0';
r = ldap_simple_bind_s(ldap, fulluser, passwd);
ldap_unbind(ldap);
if (r != LDAP_SUCCESS)
{
ereport(LOG,
(errmsg("LDAP login failed for user \"%s\" on server \"%s\": error code %d",
fulluser, server, r)));
return STATUS_ERROR;
}
return STATUS_OK;
}
#endif /* USE_LDAP */
/*
* Collect password response packet from frontend.
*
* Returns NULL if couldn't get password, else palloc'd string.
*/
static char *
recv_password_packet(Port *port)
{
StringInfoData buf;
if (PG_PROTOCOL_MAJOR(port->proto) >= 3)
{
/* Expect 'p' message type */
int mtype;
mtype = pq_getbyte();
if (mtype != 'p')
{
/*
* If the client just disconnects without offering a password,
* don't make a log entry. This is legal per protocol spec and in
* fact commonly done by psql, so complaining just clutters the
* log.
*/
if (mtype != EOF)
ereport(COMMERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("expected password response, got message type %d",
mtype)));
return NULL; /* EOF or bad message type */
}
}
else
{
/* For pre-3.0 clients, avoid log entry if they just disconnect */
if (pq_peekbyte() == EOF)
return NULL; /* EOF */
}
initStringInfo(&buf);
if (pq_getmessage(&buf, 1000)) /* receive password */
{
/* EOF - pq_getmessage already logged a suitable message */
pfree(buf.data);
return NULL;
}
/*
* Apply sanity check: password packet length should agree with length of
* contained string. Note it is safe to use strlen here because
* StringInfo is guaranteed to have an appended '\0'.
*/
if (strlen(buf.data) + 1 != buf.len)
ereport(COMMERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("invalid password packet size")));
/* Do not echo password to logs, for security. */
ereport(DEBUG5,
(errmsg("received password packet")));
/*
* Return the received string. Note we do not attempt to do any
* character-set conversion on it; since we don't yet know the client's
* encoding, there wouldn't be much point.
*/
return buf.data;
}
/*
* Called when we have sent an authorization request for a password.
* Get the response and check it.
*/
static int
recv_and_check_password_packet(Port *port)
{
char *passwd;
int result;
passwd = recv_password_packet(port);
if (passwd == NULL)
return STATUS_EOF; /* client wouldn't send password */
result = md5_crypt_verify(port, port->user_name, passwd);
pfree(passwd);
return result;
}
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