1 files changed, 313 insertions, 0 deletions
diff --git a/lib/afs/afs_funcs.c b/lib/afs/afs_funcs.c
new file mode 100644
index 0000000..c7b263c
--- /dev/null
+++ b/lib/afs/afs_funcs.c
@@ -0,0 +1,313 @@
+/*
+ *  Unix SMB/CIFS implementation.
+ *  Generate AFS tickets
+ *  Copyright (C) Volker Lendecke 2003
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "includes.h"
+#include "lib/afs/afs_funcs.h"
+
+#ifdef WITH_FAKE_KASERVER
+
+#define NO_ASN1_TYPEDEFS 1
+
+#include "secrets.h"
+#include "passdb.h"
+#include "auth.h"
+#include "../librpc/gen_ndr/ndr_netlogon.h"
+#include "lib/afs/afs_settoken.h"
+
+#include <afs/param.h>
+#include <afs/stds.h>
+#include <afs/auth.h>
+#include <afs/venus.h>
+#include <asm/unistd.h>
+#include <openssl/des.h>
+
+struct ClearToken {
+	uint32 AuthHandle;
+	char HandShakeKey[8];
+	uint32 ViceId;
+	uint32 BeginTimestamp;
+	uint32 EndTimestamp;
+};
+
+static char *afs_encode_token(const char *cell, const DATA_BLOB ticket,
+			      const struct ClearToken *ct)
+{
+	char *base64_ticket;
+	char *result = NULL;
+
+	DATA_BLOB key = data_blob(ct->HandShakeKey, 8);
+	char *base64_key;
+	TALLOC_CTX *mem_ctx;
+
+	mem_ctx = talloc_stackframe();
+	if (mem_ctx == NULL)
+		goto done;
+
+	base64_ticket = base64_encode_data_blob(mem_ctx, ticket);
+	if (base64_ticket == NULL)
+		goto done;
+
+	base64_key = base64_encode_data_blob(mem_ctx, key);
+	if (base64_key == NULL)
+		goto done;
+
+	asprintf(&result, "%s\n%u\n%s\n%u\n%u\n%u\n%s\n", cell,
+		 ct->AuthHandle, base64_key, ct->ViceId, ct->BeginTimestamp,
+		 ct->EndTimestamp, base64_ticket);
+
+	DEBUG(10, ("Got ticket string:\n%s\n", result));
+
+done:
+	TALLOC_FREE(mem_ctx);
+
+	return result;
+}
+
+/* Create a ClearToken and an encrypted ticket. ClearToken has not yet the
+ * ViceId set, this should be set by the caller. */
+
+static bool afs_createtoken(const char *username, const char *cell,
+			    DATA_BLOB *ticket, struct ClearToken *ct)
+{
+	fstring clear_ticket;
+	char *p = clear_ticket;
+	uint32 len;
+	uint32 now;
+
+	struct afs_key key;
+	des_key_schedule key_schedule;
+
+	if (!secrets_init())
+		return false;
+
+	if (!secrets_fetch_afs_key(cell, &key)) {
+		DEBUG(1, ("Could not fetch AFS service key\n"));
+		return false;
+	}
+
+	ct->AuthHandle = key.kvno;
+
+	/* Build the ticket. This is going to be encrypted, so in our
+	   way we fill in ct while we still have the unencrypted
+	   form. */
+
+	p = clear_ticket;
+
+	/* The byte-order */
+	*p = 1;
+	p += 1;
+
+	/* "Alice", the client username */
+	strncpy(p, username, sizeof(clear_ticket)-PTR_DIFF(p,clear_ticket)-1);
+	p += strlen(p)+1;
+	strncpy(p, "", sizeof(clear_ticket)-PTR_DIFF(p,clear_ticket)-1);
+	p += strlen(p)+1;
+	strncpy(p, cell, sizeof(clear_ticket)-PTR_DIFF(p,clear_ticket)-1);
+	p += strlen(p)+1;
+
+	/* Alice's network layer address. At least Openafs-1.2.10
+	   ignores this, so we fill in a dummy value here. */
+	SIVAL(p, 0, 0);
+	p += 4;
+
+	/* We need to create a session key */
+	generate_random_buffer((uint8_t *)p, 8);
+
+	/* Our client code needs the the key in the clear, it does not
+	   know the server-key ... */
+	memcpy(ct->HandShakeKey, p, 8);
+
+	p += 8;
+
+	/* This is a kerberos 4 life time. The life time is expressed
+	 * in units of 5 minute intervals up to 38400 seconds, after
+	 * that a table is used up to lifetime 0xBF. Values between
+	 * 0xC0 and 0xFF is undefined. 0xFF is defined to be the
+	 * infinite time that never expire.
+	 *
+	 * So here we cheat and use the infinite time */
+	*p = 255;
+	p += 1;
+
+	/* Ticket creation time */
+	now = time(NULL);
+	SIVAL(p, 0, now);
+	ct->BeginTimestamp = now;
+
+	if(lp_afs_token_lifetime() == 0)
+		ct->EndTimestamp = NEVERDATE;
+	else
+		ct->EndTimestamp = now + lp_afs_token_lifetime();
+
+	if (((ct->EndTimestamp - ct->BeginTimestamp) & 1) == 1) {
+		ct->BeginTimestamp += 1; /* Lifetime must be even */
+	}
+	p += 4;
+
+	/* And here comes Bob's name and instance, in this case the
+	   AFS server. */
+	strncpy(p, "afs", sizeof(clear_ticket)-PTR_DIFF(p,clear_ticket)-1);
+	p += strlen(p)+1;
+	strncpy(p, "", sizeof(clear_ticket)-PTR_DIFF(p,clear_ticket)-1);
+	p += strlen(p)+1;
+
+	/* And zero-pad to a multiple of 8 bytes */
+	len = PTR_DIFF(p, clear_ticket);
+	if (len & 7) {
+		uint32 extra_space = 8-(len & 7);
+		memset(p, 0, extra_space);
+		p+=extra_space;
+	}
+	len = PTR_DIFF(p, clear_ticket);
+
+	des_key_sched((const_des_cblock *)key.key, key_schedule);
+	des_pcbc_encrypt((const unsigned char*) clear_ticket,
+			 (unsigned char*) clear_ticket,
+			 len, key_schedule, (C_Block *)key.key, 1);
+
+	ZERO_STRUCT(key);
+
+	*ticket = data_blob(clear_ticket, len);
+
+	return true;
+}
+
+char *afs_createtoken_str(const char *username, const char *cell)
+{
+	DATA_BLOB ticket;
+	struct ClearToken ct;
+	char *result;
+
+	if (!afs_createtoken(username, cell, &ticket, &ct))
+		return NULL;
+
+	result = afs_encode_token(cell, ticket, &ct);
+
+	data_blob_free(&ticket);
+
+	return result;
+}
+
+/*
+  This routine takes a radical approach completely bypassing the
+  Kerberos idea of security and using AFS simply as an intelligent
+  file backend. Samba has persuaded itself somehow that the user is
+  actually correctly identified and then we create a ticket that the
+  AFS server hopefully accepts using its KeyFile that the admin has
+  kindly stored to our secrets.tdb.
+
+  Thanks to the book "Network Security -- PRIVATE Communication in a
+  PUBLIC World" by Charlie Kaufman, Radia Perlman and Mike Speciner
+  Kerberos 4 tickets are not really hard to construct.
+
+  For the comments "Alice" is the User to be auth'ed, and "Bob" is the
+  AFS server.  */
+
+bool afs_login(connection_struct *conn)
+{
+	const struct loadparm_substitution *lp_sub =
+		loadparm_s3_global_substitution();
+	DATA_BLOB ticket;
+	char *afs_username = NULL;
+	char *cell = NULL;
+	bool result;
+	char *ticket_str = NULL;
+	const struct dom_sid *user_sid;
+	TALLOC_CTX *ctx = talloc_tos();
+	struct dom_sid_buf buf;
+
+	struct ClearToken ct;
+
+	afs_username = talloc_strdup(ctx,
+				lp_afs_username_map());
+	if (!afs_username) {
+		return false;
+	}
+
+	afs_username = talloc_sub_advanced(ctx,
+				lp_servicename(ctx, lp_sub, SNUM(conn)),
+				conn->session_info->unix_info->unix_name,
+				conn->connectpath,
+				conn->session_info->unix_token->gid,
+				conn->session_info->unix_info->sanitized_username,
+				conn->session_info->info->domain_name,
+				afs_username);
+	if (!afs_username) {
+		return false;
+	}
+
+	user_sid = &conn->session_info->security_token->sids[0];
+	afs_username = talloc_string_sub(talloc_tos(),
+					afs_username,
+					"%s",
+					dom_sid_str_buf(user_sid, &buf));
+	if (!afs_username) {
+		return false;
+	}
+
+	/* The pts command always generates completely lower-case user
+	 * names. */
+	if (!strlower_m(afs_username)) {
+		return false;
+	}
+
+	cell = strchr(afs_username, '@');
+
+	if (cell == NULL) {
+		DEBUG(1, ("AFS username doesn't contain a @, "
+			  "could not find cell\n"));
+		return false;
+	}
+
+	*cell = '\0';
+	cell += 1;
+
+	DEBUG(10, ("Trying to log into AFS for user %s@%s\n",
+		   afs_username, cell));
+
+	if (!afs_createtoken(afs_username, cell, &ticket, &ct))
+		return false;
+
+	/* For which Unix-UID do we want to set the token? */
+	ct.ViceId = getuid();
+
+	ticket_str = afs_encode_token(cell, ticket, &ct);
+
+	result = afs_settoken_str(ticket_str);
+
+	SAFE_FREE(ticket_str);
+
+	data_blob_free(&ticket);
+
+	return result;
+}
+
+#else
+
+bool afs_login(connection_struct *conn)
+{
+	return true;
+}
+
+char *afs_createtoken_str(const char *username, const char *cell)
+{
+	return NULL;
+}
+
+#endif /* WITH_FAKE_KASERVER */