kerberos: Fix numerous segfaults when using weak crypto

Weak crypto is provided by the openssl legacy provider which is
not load by default. Load the legacy providers as needed.

When the legacy provider is loaded into the default context the default
provider will no longer be automatically loaded. Without the default
provider the various kerberos applicaions and functions will abort().

PR:			272835
MFC after:		3 days
Differential Revision:	https://reviews.freebsd.org/D43009
Tested by:		netchild, Joerg Pulz <Joerg.Pulz@frm2.tum.de>

Makefile.inc1

@@ -2635,9 +2635,10 @@ ${_bt}-usr.bin/grep: ${_bt}-lib/libbz2
 _other_bootstrap_tools+=lib/libz
 ${_bt}-lib/libdwarf: ${_bt}-lib/libz
 
-# libroken depends on libcrypt
+# libroken depends on libcrypt and libcrypto
 _other_bootstrap_tools+=lib/libcrypt
-${_bt}-lib/libroken: ${_bt}-lib/libcrypt
+_other_bootstrap_tools+=secure/lib/libcrypto
+${_bt}-lib/libroken: ${_bt}-lib/libcrypt ${_bt}-lib/libcrypto
 .else
 # All tools in _basic_bootstrap_tools have the same name as the subdirectory
 # so we can use :T to get the name of the symlinks that we need to create.
@@ -3283,7 +3284,7 @@ kerberos5/lib/libkrb5__L: kerberos5/lib/libasn1__L lib/libcom_err__L \
     lib/libcrypt__L secure/lib/libcrypto__L kerberos5/lib/libhx509__L \
     kerberos5/lib/libroken__L kerberos5/lib/libwind__L \
     kerberos5/lib/libheimbase__L kerberos5/lib/libheimipcc__L
-kerberos5/lib/libroken__L: lib/libcrypt__L
+kerberos5/lib/libroken__L: lib/libcrypt__L secure/lib/libcrypto__L
 kerberos5/lib/libwind__L: kerberos5/lib/libroken__L lib/libcom_err__L
 kerberos5/lib/libheimbase__L: lib/libthr__L
 kerberos5/lib/libheimipcc__L: kerberos5/lib/libroken__L kerberos5/lib/libheimbase__L lib/libthr__L

crypto/heimdal/lib/kadm5/create_s.c

@@ -169,6 +169,10 @@ kadm5_s_create_principal(void *server_handle,
     ent.entry.keys.len = 0;
     ent.entry.keys.val = NULL;
 
+    ret = fbsd_ossl_provider_load();
+    if (ret)
+	goto out;
+
     ret = _kadm5_set_keys(context, &ent.entry, password);
     if (ret)
 	goto out;

crypto/heimdal/lib/kadm5/kadm5_locl.h

@@ -79,5 +79,6 @@
 #include <der.h>
 #include <parse_units.h>
 #include "private.h"
+#include "fbsd_ossl_provider.h"
 
 #endif /* __KADM5_LOCL_H__ */

crypto/heimdal/lib/krb5/context.c

@@ -392,6 +392,10 @@ krb5_init_context(krb5_context *context)
     }
     HEIMDAL_MUTEX_init(p->mutex);
 
+    ret = fbsd_ossl_provider_load();
+    if(ret)
+	goto out;
+
     p->flags |= KRB5_CTX_F_HOMEDIR_ACCESS;
 
     ret = krb5_get_default_config_files(&files);

crypto/heimdal/lib/krb5/crypto.c

@@ -2054,6 +2054,9 @@ krb5_crypto_init(krb5_context context,
 	*crypto = NULL;
 	return ret;
     }
+    ret = fbsd_ossl_provider_load();
+    if (ret)
+	return ret;
     (*crypto)->key.schedule = NULL;
     (*crypto)->num_key_usage = 0;
     (*crypto)->key_usage = NULL;

crypto/heimdal/lib/krb5/salt.c

@@ -43,6 +43,8 @@ krb5_salttype_to_string (krb5_context context,
     struct _krb5_encryption_type *e;
     struct salt_type *st;
 
+    (void) fbsd_ossl_provider_load();
+
     e = _krb5_find_enctype (etype);
     if (e == NULL) {
 	krb5_set_error_message(context, KRB5_PROG_ETYPE_NOSUPP,
@@ -75,6 +77,8 @@ krb5_string_to_salttype (krb5_context context,
     struct _krb5_encryption_type *e;
     struct salt_type *st;
 
+    (void) fbsd_ossl_provider_load();
+
     e = _krb5_find_enctype (etype);
     if (e == NULL) {
 	krb5_set_error_message(context, KRB5_PROG_ETYPE_NOSUPP,
@@ -196,6 +200,7 @@ krb5_string_to_key_data_salt_opaque (krb5_context context,
 			       enctype);
 	return KRB5_PROG_ETYPE_NOSUPP;
     }
+    (void) fbsd_ossl_provider_load();
     for(st = et->keytype->string_to_key; st && st->type; st++)
 	if(st->type == salt.salttype)
 	    return (*st->string_to_key)(context, enctype, password,

crypto/heimdal/lib/roken/version-script.map

@@ -13,6 +13,7 @@ HEIMDAL_ROKEN_1.0 {
 		ct_memcmp;
 		err;
 		errx;
+		fbsd_ossl_provider_load;
 		free_getarg_strings;
 		get_default_username;
 		get_window_size;

kerberos5/include/crypto-headers.h

@@ -17,5 +17,9 @@
 #include <openssl/ec.h>
 #include <openssl/ecdsa.h>
 #include <openssl/ecdh.h>
+#if defined(OPENSSL_VERSION_MAJOR) && (OPENSSL_VERSION_MAJOR >= 3)
+#include <openssl/provider.h>
+#include "fbsd_ossl_provider.h"
+#endif
 
 #endif /* __crypto_headers_h__ */

kerberos5/include/fbsd_ossl_provider.h

@@ -0,0 +1,4 @@
+#ifndef __fbsd_ossl_provider_h
+#define __fbsd_ossl_provider_h
+int  fbsd_ossl_provider_load(void);
+#endif

kerberos5/lib/libroken/Makefile

@@ -2,7 +2,7 @@
 PACKAGE=	kerberos-lib
 
 LIB=	roken
-LIBADD=	crypt
+LIBADD=	crypt crypto
 VERSION_MAP=	${KRB5DIR}/lib/roken/version-script.map
 INCS=	roken.h \
 	roken-common.h \
@@ -74,15 +74,20 @@ SRCS=	base64.c \
 	vis.c \
 	warnerr.c \
 	write_pid.c \
-	xfree.c
+	xfree.c \
+	fbsd_ossl_provider_load.c
 
-CFLAGS+=-I${KRB5DIR}/lib/roken -I.
+CFLAGS+=-I${KRB5DIR}/lib/roken \
+	-I${SRCTOP}/kerberos5/include \
+	-I${KRB5DIR}/lib/krb5 \
+	-I${SRCTOP}/crypto/openssl/include -I.
 
 CLEANFILES= roken.h
 
 roken.h:
 	${MAKE_ROKEN} > ${.TARGET}
 
+
 .include <bsd.lib.mk>
 
 .PATH: ${KRB5DIR}/lib/roken

kerberos5/lib/libroken/fbsd_ossl_provider_load.c

@@ -0,0 +1,41 @@
+#include <errno.h>
+#include <krb5_locl.h>
+
+static void fbsd_ossl_provider_unload(void);
+
+static OSSL_PROVIDER *legacy;
+static OSSL_PROVIDER *deflt;
+static int providers_loaded = 0;
+
+int
+fbsd_ossl_provider_load(void)
+{
+#if defined(OPENSSL_VERSION_MAJOR) && (OPENSSL_VERSION_MAJOR >= 3)
+	if (providers_loaded == 0) {
+		if ((legacy = OSSL_PROVIDER_load(NULL, "legacy")) == NULL)
+			return (EINVAL);
+		if ((deflt = OSSL_PROVIDER_load(NULL, "default")) == NULL) {
+			OSSL_PROVIDER_unload(legacy);
+			return (EINVAL);
+		}
+		if (atexit(fbsd_ossl_provider_unload)) {
+			fbsd_ossl_provider_unload();
+			return (errno);
+		}
+		providers_loaded = 1;
+	}
+#endif
+	return (0);
+}
+
+static void
+fbsd_ossl_provider_unload(void)
+{
+#if defined(OPENSSL_VERSION_MAJOR) && (OPENSSL_VERSION_MAJOR >= 3)
+	if (providers_loaded == 1) {
+		OSSL_PROVIDER_unload(legacy);
+		OSSL_PROVIDER_unload(deflt);
+		providers_loaded = 0;
+	}
+#endif
+}

kerberos5/libexec/kdc/Makefile

@@ -11,7 +11,7 @@ SRCS=	config.c \
 
 CFLAGS+=-I${KRB5DIR}/lib/krb5 -I${KRB5DIR}/lib/asn1 -I${KRB5DIR}/lib/roken \
 	-I${KRB5DIR}/kdc -I${SRCTOP}/contrib/com_err ${LDAPCFLAGS}
-LIBADD=	kdc hdb krb5 roken crypt vers
+LIBADD=	kdc hdb krb5 roken crypt vers crypto
 LDFLAGS=${LDAPLDFLAGS}
 
 .include <bsd.prog.mk>

share/mk/src.libnames.mk

@@ -367,7 +367,7 @@ _DP_pam+=	ssh
 .if ${MK_NIS} != "no"
 _DP_pam+=	ypclnt
 .endif
-_DP_roken=	crypt
+_DP_roken=	crypt crypto
 _DP_kadm5clnt=	com_err krb5 roken
 _DP_kadm5srv=	com_err hdb krb5 roken
 _DP_heimntlm=	crypto com_err krb5 roken