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