new for kerberos support

1 files changed, 471 insertions, 0 deletions

diff --git a/lib/krb4.c b/lib/krb4.c
new file mode 100644
index 000000000..79b968c1a
--- /dev/null
+++ b/lib/krb4.c
@@ -0,0 +1,471 @@
+/* modified by Martin Hedenfalk <mhe@stacken.kth.se> for use in Curl
+ * last modified 2000-09-18
+ */
+
+/*
+ * Copyright (c) 1995, 1996, 1997, 1998, 1999 Kungliga Tekniska Högskolan
+ * (Royal Institute of Technology, Stockholm, Sweden).
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 
+ * 3. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "setup.h"
+
+#ifdef KRB4
+
+#include "security.h"
+#include "base64_krb.h"
+#include <stdlib.h>
+#include <netdb.h>
+#include <syslog.h>
+#include <string.h>
+#include <krb.h>
+
+#ifdef FTP_SERVER
+#define LOCAL_ADDR ctrl_addr
+#define REMOTE_ADDR his_addr
+#else
+/*#define LOCAL_ADDR myctladdr***/
+/*#define REMOTE_ADDR hisctladdr***/
+#endif
+
+/*extern struct sockaddr *LOCAL_ADDR, *REMOTE_ADDR;***/
+
+#define LOCAL_ADDR (&local_addr)
+#define REMOTE_ADDR (&conn->serv_addr)
+#define myctladdr LOCAL_ADDR
+#define hisctladdr REMOTE_ADDR
+
+static struct sockaddr_in local_addr;
+
+struct krb4_data {
+    des_cblock key;
+    des_key_schedule schedule;
+    char name[ANAME_SZ];
+    char instance[INST_SZ];
+    char realm[REALM_SZ];
+};
+
+static int
+krb4_check_prot(void *app_data, int level)
+{
+    if(level == prot_confidential)
+	return -1;
+    return 0;
+}
+
+static int
+krb4_decode(void *app_data, void *buf, int len, int level,
+	    struct connectdata *conn)
+{
+    MSG_DAT m;
+    int e;
+    struct krb4_data *d = app_data;
+    
+    if(level == prot_safe)
+	e = krb_rd_safe(buf, len, &d->key,
+			(struct sockaddr_in *)REMOTE_ADDR,
+			(struct sockaddr_in *)LOCAL_ADDR, &m);
+    else
+	e = krb_rd_priv(buf, len, d->schedule, &d->key, 
+			(struct sockaddr_in *)REMOTE_ADDR,
+			(struct sockaddr_in *)LOCAL_ADDR, &m);
+    if(e){
+	syslog(LOG_ERR, "krb4_decode: %s", krb_get_err_text(e));
+	return -1;
+    }
+    memmove(buf, m.app_data, m.app_length);
+    return m.app_length;
+}
+
+static int
+krb4_overhead(void *app_data, int level, int len)
+{
+    return 31;
+}
+
+static int
+krb4_encode(void *app_data, void *from, int length, int level, void **to,
+	    struct connectdata *conn)
+{
+    struct krb4_data *d = app_data;
+    *to = malloc(length + 31);
+    if(level == prot_safe)
+	return krb_mk_safe(from, *to, length, &d->key, 
+			   (struct sockaddr_in *)LOCAL_ADDR,
+			   (struct sockaddr_in *)REMOTE_ADDR);
+    else if(level == prot_private)
+	return krb_mk_priv(from, *to, length, d->schedule, &d->key, 
+			   (struct sockaddr_in *)LOCAL_ADDR,
+			   (struct sockaddr_in *)REMOTE_ADDR);
+    else
+	return -1;
+}
+
+#ifdef FTP_SERVER
+
+static int
+krb4_adat(void *app_data, void *buf, size_t len)
+{
+    KTEXT_ST tkt;
+    AUTH_DAT auth_dat;
+    char *p;
+    int kerror;
+    u_int32_t cs;
+    char msg[35]; /* size of encrypted block */
+    int tmp_len;
+    struct krb4_data *d = app_data;
+    char inst[INST_SZ];
+    struct sockaddr_in *his_addr_sin = (struct sockaddr_in *)his_addr;
+
+    memcpy(tkt.dat, buf, len);
+    tkt.length = len;
+
+    k_getsockinst(0, inst, sizeof(inst));
+    kerror = krb_rd_req(&tkt, "ftp", inst, 
+			his_addr_sin->sin_addr.s_addr, &auth_dat, "");
+    if(kerror == RD_AP_UNDEC){
+	k_getsockinst(0, inst, sizeof(inst));
+	kerror = krb_rd_req(&tkt, "rcmd", inst, 
+			    his_addr_sin->sin_addr.s_addr, &auth_dat, "");
+    }
+
+    if(kerror){
+	reply(535, "Error reading request: %s.", krb_get_err_text(kerror));
+	return -1;
+    }
+    
+    memcpy(d->key, auth_dat.session, sizeof(d->key));
+    des_set_key(&d->key, d->schedule);
+
+    strlcpy(d->name, auth_dat.pname, sizeof(d->name));
+    strlcpy(d->instance, auth_dat.pinst, sizeof(d->instance));
+    strlcpy(d->realm, auth_dat.prealm, sizeof(d->instance));
+
+    cs = auth_dat.checksum + 1;
+    {
+	unsigned char tmp[4];
+	KRB_PUT_INT(cs, tmp, 4, sizeof(tmp));
+	tmp_len = krb_mk_safe(tmp, msg, 4, &d->key,
+			      (struct sockaddr_in *)LOCAL_ADDR,
+			      (struct sockaddr_in *)REMOTE_ADDR);
+    }
+    if(tmp_len < 0){
+	reply(535, "Error creating reply: %s.", strerror(errno));
+	return -1;
+    }
+    len = tmp_len;
+    if(base64_encode(msg, len, &p) < 0) {
+	reply(535, "Out of memory base64-encoding.");
+	return -1;
+    }
+    reply(235, "ADAT=%s", p);
+    sec_complete = 1;
+    free(p);
+    return 0;
+}
+
+static int
+krb4_userok(void *app_data, char *user)
+{
+    struct krb4_data *d = app_data;
+    return krb_kuserok(d->name, d->instance, d->realm, user);
+}
+
+struct sec_server_mech krb4_server_mech = {
+    "KERBEROS_V4",
+    sizeof(struct krb4_data),
+    NULL, /* init */
+    NULL, /* end */
+    krb4_check_prot,
+    krb4_overhead,
+    krb4_encode,
+    krb4_decode,
+    /* */
+    NULL,
+    krb4_adat,
+    NULL, /* pbsz */
+    NULL, /* ccc */
+    krb4_userok
+};
+
+#else /* FTP_SERVER */
+
+static int
+mk_auth(struct krb4_data *d, KTEXT adat, 
+	char *service, char *host, int checksum)
+{
+    int ret;
+    CREDENTIALS cred;
+    char sname[SNAME_SZ], inst[INST_SZ], realm[REALM_SZ];
+
+    strlcpy(sname, service, sizeof(sname));
+    strlcpy(inst, krb_get_phost(host), sizeof(inst));
+    strlcpy(realm, krb_realmofhost(host), sizeof(realm));
+    ret = krb_mk_req(adat, sname, inst, realm, checksum);
+    if(ret)
+	return ret;
+    strlcpy(sname, service, sizeof(sname));
+    strlcpy(inst, krb_get_phost(host), sizeof(inst));
+    strlcpy(realm, krb_realmofhost(host), sizeof(realm));
+    ret = krb_get_cred(sname, inst, realm, &cred);
+    memmove(&d->key, &cred.session, sizeof(des_cblock));
+    des_key_sched(&d->key, d->schedule);
+    memset(&cred, 0, sizeof(cred));
+    return ret;
+}
+
+static int
+krb4_auth(void *app_data, struct connectdata *conn)
+{
+    int ret;
+    char *p;
+    int len;
+    KTEXT_ST adat;
+    MSG_DAT msg_data;
+    int checksum;
+    u_int32_t cs;
+    struct krb4_data *d = app_data;
+    struct sockaddr_in *localaddr  = (struct sockaddr_in *)LOCAL_ADDR;
+    struct sockaddr_in *remoteaddr = (struct sockaddr_in *)REMOTE_ADDR;
+    char *host = conn->hp->h_name;
+    size_t nread;
+    int l = sizeof(local_addr);
+
+    if(getsockname(conn->data->firstsocket, LOCAL_ADDR, &l) < 0)
+	perror("getsockname()");
+
+    checksum = getpid();
+    ret = mk_auth(d, &adat, "ftp", host, checksum);
+    if(ret == KDC_PR_UNKNOWN)
+	ret = mk_auth(d, &adat, "rcmd", host, checksum);
+    if(ret){
+	printf("%s\n", krb_get_err_text(ret));
+	return AUTH_CONTINUE;
+    }
+
+#ifdef HAVE_KRB_GET_OUR_IP_FOR_REALM
+    if (krb_get_config_bool("nat_in_use")) {
+      struct in_addr natAddr;
+
+      if (krb_get_our_ip_for_realm(krb_realmofhost(host),
+				   &natAddr) != KSUCCESS
+	  && krb_get_our_ip_for_realm(NULL, &natAddr) != KSUCCESS)
+	printf("Can't get address for realm %s\n",
+	       krb_realmofhost(host));
+      else {
+	if (natAddr.s_addr != localaddr->sin_addr.s_addr) {
+	  printf("Using NAT IP address (%s) for kerberos 4\n",
+		 inet_ntoa(natAddr));
+	  localaddr->sin_addr = natAddr;
+	  
+	  /*
+	   * This not the best place to do this, but it
+	   * is here we know that (probably) NAT is in
+	   * use!
+	   */
+
+	  /*passivemode = 1;***/
+	  /*printf("Setting: Passive mode on.\n");***/
+	}
+      }
+    }
+#endif
+
+    /*printf("Local address is %s\n", inet_ntoa(localaddr->sin_addr));***/
+    /*printf("Remote address is %s\n", inet_ntoa(remoteaddr->sin_addr));***/
+
+    if(base64_encode(adat.dat, adat.length, &p) < 0) {
+	printf("Out of memory base64-encoding.\n");
+	return AUTH_CONTINUE;
+    }
+    /*ret = command("ADAT %s", p)*/
+    ftpsendf(conn->data->firstsocket, conn, "ADAT %s", p);
+    /* wait for feedback */
+    nread = GetLastResponse(conn->data->firstsocket,
+			    conn->data->buffer, conn);
+    if(nread < 0)
+	return /*CURLE_OPERATION_TIMEOUTED*/-1;
+    free(p);
+
+    if(/*ret != COMPLETE*/conn->data->buffer[0] != '2'){
+	printf("Server didn't accept auth data.\n");
+	return AUTH_ERROR;
+    }
+
+    p = strstr(/*reply_string*/conn->data->buffer, "ADAT=");
+    if(!p){
+	printf("Remote host didn't send adat reply.\n");
+	return AUTH_ERROR;
+    }
+    p += 5;
+    len = base64_decode(p, adat.dat);
+    if(len < 0){
+	printf("Failed to decode base64 from server.\n");
+	return AUTH_ERROR;
+    }
+    adat.length = len;
+    ret = krb_rd_safe(adat.dat, adat.length, &d->key, 
+		      (struct sockaddr_in *)hisctladdr, 
+		      (struct sockaddr_in *)myctladdr, &msg_data);
+    if(ret){
+	printf("Error reading reply from server: %s.\n", 
+	       krb_get_err_text(ret));
+	return AUTH_ERROR;
+    }
+    krb_get_int(msg_data.app_data, &cs, 4, 0);
+    if(cs - checksum != 1){
+	printf("Bad checksum returned from server.\n");
+	return AUTH_ERROR;
+    }
+    return AUTH_OK;
+}
+
+struct sec_client_mech krb4_client_mech = {
+    "KERBEROS_V4",
+    sizeof(struct krb4_data),
+    NULL, /* init */
+    krb4_auth,
+    NULL, /* end */
+    krb4_check_prot,
+    krb4_overhead,
+    krb4_encode,
+    krb4_decode
+};
+
+#endif /* FTP_SERVER */
+
+void krb_kauth(struct connectdata *conn)
+{
+    int ret;
+    char buf[1024];
+    des_cblock key;
+    des_key_schedule schedule;
+    KTEXT_ST tkt, tktcopy;
+    char *name;
+    char *p;
+    int overbose;
+    char passwd[100];
+    int tmp;
+    size_t nread;
+	
+    int save;
+
+    save = set_command_prot(conn, prot_private);
+    /*ret = command("SITE KAUTH %s", name);***/
+    ftpsendf(conn->data->firstsocket, conn,
+             "SITE KAUTH %s", conn->data->user);
+    /* wait for feedback */
+    nread = GetLastResponse(conn->data->firstsocket, conn->data->buffer, conn);
+    if(nread < 0)
+	return /*CURLE_OPERATION_TIMEOUTED*/;
+
+    if(/*ret != CONTINUE*/conn->data->buffer[0] != '3'){
+	/*verbose = overbose;***/
+	set_command_prot(conn, save);
+	/*code = -1;***/
+	return;
+    }
+    /*verbose = overbose;***/
+    p = strstr(/*reply_string***/conn->data->buffer, "T=");
+    if(!p){
+	printf("Bad reply from server.\n");
+	set_command_prot(conn, save);
+	/*code = -1;***/
+	return;
+    }
+    p += 2;
+    tmp = base64_decode(p, &tkt.dat);
+    if(tmp < 0){
+	printf("Failed to decode base64 in reply.\n");
+	set_command_prot(conn, save);
+	/*code = -1;***/
+	return;
+    }
+    tkt.length = tmp;
+    tktcopy.length = tkt.length;
+    
+    p = strstr(/*reply_string***/conn->data->buffer, "P=");
+    if(!p){
+	printf("Bad reply from server.\n");
+	/*verbose = overbose;***/
+	set_command_prot(conn, save);
+	/*code = -1;***/
+	return;
+    }
+    name = p + 2;
+    for(; *p && *p != ' ' && *p != '\r' && *p != '\n'; p++);
+    *p = 0;
+
+#if 0
+    snprintf(buf, sizeof(buf), "Password for %s:", name);
+    if (des_read_pw_string (passwd, sizeof(passwd)-1, buf, 0))
+        *passwd = '\0';
+    des_string_to_key (passwd, &key);
+#else
+    des_string_to_key (conn->data->passwd, &key);
+#endif
+
+    des_key_sched(&key, schedule);
+    
+    des_pcbc_encrypt((des_cblock*)tkt.dat, (des_cblock*)tktcopy.dat,
+		     tkt.length,
+		     schedule, &key, DES_DECRYPT);
+    if (strcmp ((char*)tktcopy.dat + 8,
+		KRB_TICKET_GRANTING_TICKET) != 0) {
+        afs_string_to_key (passwd,
+			   krb_realmofhost(/*hostname***/conn->hp->h_name),
+			   &key);
+	des_key_sched (&key, schedule);
+	des_pcbc_encrypt((des_cblock*)tkt.dat, (des_cblock*)tktcopy.dat,
+			 tkt.length,
+			 schedule, &key, DES_DECRYPT);
+    }
+    memset(key, 0, sizeof(key));
+    memset(schedule, 0, sizeof(schedule));
+    memset(passwd, 0, sizeof(passwd));
+    if(base64_encode(tktcopy.dat, tktcopy.length, &p) < 0) {
+      failf(conn->data, "Out of memory base64-encoding.\n");
+      set_command_prot(conn, save);
+      /*code = -1;***/
+      return;
+    }
+    memset (tktcopy.dat, 0, tktcopy.length);
+    /*ret = command("SITE KAUTH %s %s", name, p);***/
+    ftpsendf(conn->data->firstsocket, conn,
+             "SITE KAUTH %s %s", name, p);
+    /* wait for feedback */
+    nread = GetLastResponse(conn->data->firstsocket, conn->data->buffer, conn);
+    if(nread < 0)
+	return /*CURLE_OPERATION_TIMEOUTED*/;
+    free(p);
+    set_command_prot(conn, save);
+}
+
+#endif /* KRB4 */