Add BSD authentication method.

Create a "bsd" auth method that works the same as "password" so far as
clients are concerned, but calls the BSD Authentication service to
check the password.  This is currently only available on OpenBSD.

Marisa Emerson, reviewed by Thomas Munro

src/backend/libpq/auth.c

@@ -88,6 +88,17 @@ static Port *pam_port_cludge;	/* Workaround for passing "Port *port" into
 #endif   /* USE_PAM */
 
 
+/*----------------------------------------------------------------
+ * BSD authentication
+ *----------------------------------------------------------------
+ */
+#ifdef USE_BSD_AUTH
+#include <bsd_auth.h>
+
+static int	CheckBSDAuth(Port *port, char *user);
+#endif   /* USE_BSD_AUTH */
+
+
 /*----------------------------------------------------------------
  * LDAP authentication
  *----------------------------------------------------------------
@@ -258,6 +269,9 @@ auth_failed(Port *port, int status, char *logdetail)
 		case uaPAM:
 			errstr = gettext_noop("PAM authentication failed for user \"%s\"");
 			break;
+		case uaBSD:
+			errstr = gettext_noop("BSD authentication failed for user \"%s\"");
+			break;
 		case uaLDAP:
 			errstr = gettext_noop("LDAP authentication failed for user \"%s\"");
 			break;
@@ -529,6 +543,14 @@ ClientAuthentication(Port *port)
 #endif   /* USE_PAM */
 			break;
 
+		case uaBSD:
+#ifdef USE_BSD_AUTH
+			status = CheckBSDAuth(port, port->user_name);
+#else
+			Assert(false);
+#endif   /* USE_BSD_AUTH */
+			break;
+
 		case uaLDAP:
 #ifdef USE_LDAP
 			status = CheckLDAPAuth(port);
@@ -1856,6 +1878,38 @@ CheckPAMAuth(Port *port, char *user, char *password)
 #endif   /* USE_PAM */
 
 
+/*----------------------------------------------------------------
+ * BSD authentication system
+ *----------------------------------------------------------------
+ */
+#ifdef USE_BSD_AUTH
+static int
+CheckBSDAuth(Port *port, char *user)
+{
+	char *passwd;
+	int retval;
+
+	/* Send regular password request to client, and get the response */
+	sendAuthRequest(port, AUTH_REQ_PASSWORD);
+
+	passwd = recv_password_packet(port);
+	if (passwd == NULL)
+		return STATUS_EOF;
+
+	/*
+	 * Ask the BSD auth system to verify password.  Note that auth_userokay
+	 * will overwrite the password string with zeroes, but it's just a
+	 * temporary string so we don't care.
+	 */
+	retval = auth_userokay(user, NULL, "auth-postgresql", passwd);
+
+	if (!retval)
+		return STATUS_ERROR;
+
+	return STATUS_OK;
+}
+#endif   /* USE_BSD_AUTH */
+
 
 /*----------------------------------------------------------------
  * LDAP authentication system

src/backend/libpq/hba.c

@@ -1189,6 +1189,12 @@ parse_hba_line(List *line, int line_num, char *raw_line)
 		parsedline->auth_method = uaPAM;
 #else
 		unsupauth = "pam";
+#endif
+	else if (strcmp(token->string, "bsd") == 0)
+#ifdef USE_BSD_AUTH
+		parsedline->auth_method = uaBSD;
+#else
+		unsupauth = "bsd";
 #endif
 	else if (strcmp(token->string, "ldap") == 0)
 #ifdef USE_LDAP

src/bin/initdb/initdb.c

@@ -90,6 +90,9 @@ static const char *const auth_methods_host[] = {
 #ifdef USE_PAM
 	"pam", "pam ",
 #endif
+#ifdef USE_BSD_AUTH
+	"bsd",
+#endif
 #ifdef USE_LDAP
 	"ldap",
 #endif
@@ -103,6 +106,9 @@ static const char *const auth_methods_local[] = {
 #ifdef USE_PAM
 	"pam", "pam ",
 #endif
+#ifdef USE_BSD_AUTH
+	"bsd",
+#endif
 #ifdef USE_LDAP
 	"ldap",
 #endif

src/include/libpq/hba.h

@@ -27,6 +27,7 @@ typedef enum UserAuth
 	uaGSS,
 	uaSSPI,
 	uaPAM,
+	uaBSD,
 	uaLDAP,
 	uaCert,
 	uaRADIUS,

src/include/pg_config.h.in

@@ -793,6 +793,9 @@
 /* Define to 1 to build with Bonjour support. (--with-bonjour) */
 #undef USE_BONJOUR
 
+/* Define to 1 to build with BSD Authentication support. (--with-bsd-auth) */
+#undef USE_BSD_AUTH
+
 /* Define to 1 if you want float4 values to be passed by value.
    (--enable-float4-byval) */
 #undef USE_FLOAT4_BYVAL

src/include/pg_config.h.win32

@@ -613,6 +613,9 @@
 /* Define to 1 to build with Bonjour support. (--with-bonjour) */
 /* #undef USE_BONJOUR */
 
+/* Define to 1 to build with BSD Authentication support. (--with-bsd-auth) */
+/* #undef USE_BSD_AUTH */
+
 /* Define to 1 if you want 64-bit integer timestamp and interval support.
    (--enable-integer-datetimes) */
 /* #undef USE_INTEGER_DATETIMES */