new for kerberos support

1 files changed, 641 insertions, 0 deletions

diff --git a/lib/security.c b/lib/security.c
new file mode 100644
index 000000000..81ce35ed8
--- /dev/null
+++ b/lib/security.c
@@ -0,0 +1,641 @@
+/* modified by Martin Hedenfalk <mhe@stacken.kth.se> for use in Curl
+ * last modified 2000-09-18
+ * Even more obscurified to merge better into libcurl by Daniel Stenberg.
+ */
+
+/*
+ * Copyright (c) 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"
+
+#include <curl/mprintf.h>
+
+#ifdef KRB4
+
+#include "security.h"
+#include <stdlib.h>
+#include <string.h>
+#include <netdb.h>
+#include "base64_krb.h"
+
+#define min(a, b)   ((a) < (b) ? (a) : (b))
+
+static struct {
+    enum protection_level level;
+    const char *name;
+} level_names[] = {
+    { prot_clear, "clear" },
+    { prot_safe, "safe" },
+    { prot_confidential, "confidential" },
+    { prot_private, "private" }
+};
+
+static const char *
+level_to_name(enum protection_level level)
+{
+    int i;
+    for(i = 0; i < sizeof(level_names) / sizeof(level_names[0]); i++)
+	if(level_names[i].level == level)
+	    return level_names[i].name;
+    return "unknown";
+}
+
+#ifndef FTP_SERVER /* not used in server */
+static enum protection_level 
+name_to_level(const char *name)
+{
+    int i;
+    for(i = 0; i < sizeof(level_names) / sizeof(level_names[0]); i++)
+	if(!strncasecmp(level_names[i].name, name, strlen(name)))
+	    return level_names[i].level;
+    return (enum protection_level)-1;
+}
+#endif
+
+#ifdef FTP_SERVER
+
+static struct sec_server_mech *mechs[] = {
+#ifdef KRB5
+    &gss_server_mech,
+#endif
+#ifdef KRB4
+    &krb4_server_mech,
+#endif
+    NULL
+};
+
+static struct sec_server_mech *mech;
+
+#else
+
+static struct sec_client_mech *mechs[] = {
+#ifdef KRB5
+    &gss_client_mech,
+#endif
+#ifdef KRB4
+    &krb4_client_mech,
+#endif
+    NULL
+};
+
+static struct sec_client_mech *mech;
+
+#endif
+
+int
+sec_getc(struct connectdata *conn, FILE *F)
+{
+  if(conn->sec_complete && conn->data_prot) {
+    char c;
+    if(sec_read(conn, fileno(F), &c, 1) <= 0)
+      return EOF;
+    return c;
+  } else
+    return getc(F);
+}
+
+static int
+block_read(int fd, void *buf, size_t len)
+{
+    unsigned char *p = buf;
+    int b;
+    while(len) {
+	b = read(fd, p, len);
+	if (b == 0)
+	    return 0;
+	else if (b < 0)
+	    return -1;
+	len -= b;
+	p += b;
+    }
+    return p - (unsigned char*)buf;
+}
+
+static int
+block_write(int fd, void *buf, size_t len)
+{
+    unsigned char *p = buf;
+    int b;
+    while(len) {
+	b = write(fd, p, len);
+	if(b < 0)
+	    return -1;
+	len -= b;
+	p += b;
+    }
+    return p - (unsigned char*)buf;
+}
+
+static int
+sec_get_data(struct connectdata *conn,
+             int fd, struct krb4buffer *buf, int level)
+{
+  int len;
+  int b;
+
+  b = block_read(fd, &len, sizeof(len));
+  if (b == 0)
+    return 0;
+  else if (b < 0)
+    return -1;
+  len = ntohl(len);
+  buf->data = realloc(buf->data, len);
+  b = block_read(fd, buf->data, len);
+  if (b == 0)
+    return 0;
+  else if (b < 0)
+    return -1;
+  buf->size = (*mech->decode)(conn->app_data, buf->data, len,
+                              conn->data_prot, conn);
+  buf->index = 0;
+  return 0;
+}
+
+static size_t
+buffer_read(struct krb4buffer *buf, void *data, size_t len)
+{
+    len = min(len, buf->size - buf->index);
+    memcpy(data, (char*)buf->data + buf->index, len);
+    buf->index += len;
+    return len;
+}
+
+static size_t
+buffer_write(struct krb4buffer *buf, void *data, size_t len)
+{
+    if(buf->index + len > buf->size) {
+	void *tmp;
+	if(buf->data == NULL)
+	    tmp = malloc(1024);
+	else
+	    tmp = realloc(buf->data, buf->index + len);
+	if(tmp == NULL)
+	    return -1;
+	buf->data = tmp;
+	buf->size = buf->index + len;
+    }
+    memcpy((char*)buf->data + buf->index, data, len);
+    buf->index += len;
+    return len;
+}
+
+int
+sec_read(struct connectdata *conn, int fd, void *buffer, int length)
+{
+    size_t len;
+    int rx = 0;
+
+    if(conn->sec_complete == 0 || conn->data_prot == 0)
+      return read(fd, buffer, length);
+
+    if(conn->in_buffer.eof_flag){
+      conn->in_buffer.eof_flag = 0;
+      return 0;
+    }
+    
+    len = buffer_read(&conn->in_buffer, buffer, length);
+    length -= len;
+    rx += len;
+    buffer = (char*)buffer + len;
+    
+    while(length) {
+      if(sec_get_data(conn, fd, &conn->in_buffer, conn->data_prot) < 0)
+        return -1;
+      if(conn->in_buffer.size == 0) {
+        if(rx)
+          conn->in_buffer.eof_flag = 1;
+        return rx;
+      }
+      len = buffer_read(&conn->in_buffer, buffer, length);
+      length -= len;
+      rx += len;
+      buffer = (char*)buffer + len;
+    }
+    return rx;
+}
+
+static int
+sec_send(struct connectdata *conn, int fd, char *from, int length)
+{
+  int bytes;
+  void *buf;
+  bytes = (*mech->encode)(conn->app_data, from, length, conn->data_prot, &buf, conn);
+  bytes = htonl(bytes);
+  block_write(fd, &bytes, sizeof(bytes));
+  block_write(fd, buf, ntohl(bytes));
+  free(buf);
+  return length;
+}
+
+int
+sec_fflush(struct connectdata *conn, FILE *F)
+{
+  if(conn->data_prot != prot_clear) {
+    if(conn->out_buffer.index > 0){
+      sec_write(conn, fileno(F),
+                conn->out_buffer.data, conn->out_buffer.index);
+      conn->out_buffer.index = 0;
+    }
+    sec_send(conn, fileno(F), NULL, 0);
+  }
+  fflush(F);
+  return 0;
+}
+
+int
+sec_write(struct connectdata *conn, int fd, char *buffer, int length)
+{
+  int len = conn->buffer_size;
+  int tx = 0;
+      
+  if(conn->data_prot == prot_clear)
+    return write(fd, buffer, length);
+
+  len -= (*mech->overhead)(conn->app_data, conn->data_prot, len);
+  while(length){
+    if(length < len)
+      len = length;
+    sec_send(conn, fd, buffer, len);
+    length -= len;
+    buffer += len;
+    tx += len;
+  }
+  return tx;
+}
+
+int
+sec_vfprintf2(struct connectdata *conn, FILE *f, const char *fmt, va_list ap)
+{
+  char *buf;
+  int ret;
+  if(conn->data_prot == prot_clear)
+    return vfprintf(f, fmt, ap);
+  else {
+    buf = maprintf(fmt, ap);
+    ret = buffer_write(&conn->out_buffer, buf, strlen(buf));
+    free(buf);
+    return ret;
+  }
+}
+
+int
+sec_fprintf2(struct connectdata *conn, FILE *f, const char *fmt, ...)
+{
+    int ret;
+    va_list ap;
+    va_start(ap, fmt);
+    ret = sec_vfprintf2(conn, f, fmt, ap);
+    va_end(ap);
+    return ret;
+}
+
+int
+sec_putc(struct connectdata *conn, int c, FILE *F)
+{
+  char ch = c;
+  if(conn->data_prot == prot_clear)
+    return putc(c, F);
+    
+  buffer_write(&conn->out_buffer, &ch, 1);
+  if(c == '\n' || conn->out_buffer.index >= 1024 /* XXX */) {
+    sec_write(conn, fileno(F), conn->out_buffer.data, conn->out_buffer.index);
+    conn->out_buffer.index = 0;
+  }
+  return c;
+}
+
+int
+sec_read_msg(struct connectdata *conn, char *s, int level)
+{
+    int len;
+    char *buf;
+    int code;
+    
+    buf = malloc(strlen(s));
+    len = base64_decode(s + 4, buf); /* XXX */
+    
+    len = (*mech->decode)(conn->app_data, buf, len, level, conn);
+    if(len < 0)
+	return -1;
+    
+    buf[len] = '\0';
+
+    if(buf[3] == '-')
+	code = 0;
+    else
+	sscanf(buf, "%d", &code);
+    if(buf[len-1] == '\n')
+	buf[len-1] = '\0';
+    strcpy(s, buf);
+    free(buf);
+    return code;
+}
+
+/* modified to return how many bytes written, or -1 on error ***/
+int
+sec_vfprintf(struct connectdata *conn, FILE *f, const char *fmt, va_list ap)
+{
+    int ret = 0;
+    char *buf;
+    void *enc;
+    int len;
+    if(!conn->sec_complete)
+	return vfprintf(f, fmt, ap);
+    
+    buf = maprintf(fmt, ap);
+    len = (*mech->encode)(conn->app_data, buf, strlen(buf),
+                          conn->command_prot, &enc,
+			  conn);
+    free(buf);
+    if(len < 0) {
+	failf(conn->data, "Failed to encode command.\n");
+	return -1;
+    }
+    if(base64_encode(enc, len, &buf) < 0){
+      failf(conn->data, "Out of memory base64-encoding.\n");
+      return -1;
+    }
+#ifdef FTP_SERVER
+    if(command_prot == prot_safe)
+	fprintf(f, "631 %s\r\n", buf);
+    else if(command_prot == prot_private)
+	fprintf(f, "632 %s\r\n", buf);
+    else if(command_prot == prot_confidential)
+	fprintf(f, "633 %s\r\n", buf);
+#else
+    if(conn->command_prot == prot_safe)
+	ret = fprintf(f, "MIC %s", buf);
+    else if(conn->command_prot == prot_private)
+	ret = fprintf(f, "ENC %s", buf);
+    else if(conn->command_prot == prot_confidential)
+	ret = fprintf(f, "CONF %s", buf);
+#endif
+    free(buf);
+    return ret;
+}
+
+int
+sec_fprintf(struct connectdata *conn, FILE *f, const char *fmt, ...)
+{
+    va_list ap;
+    int ret;
+    va_start(ap, fmt);
+    ret = sec_vfprintf(conn, f, fmt, ap);
+    va_end(ap);
+    return ret;
+}
+
+/* end common stuff */
+
+#ifdef FTP_SERVER
+
+/* snip */
+
+#else /* FTP_SERVER */
+
+#if 0
+void
+sec_status(void)
+{
+    if(conn->sec_complete){
+	printf("Using %s for authentication.\n", mech->name);
+	printf("Using %s command channel.\n", level_to_name(command_prot));
+	printf("Using %s data channel.\n", level_to_name(data_prot));
+	if(buffer_size > 0)
+	    printf("Protection buffer size: %lu.\n", 
+		   (unsigned long)buffer_size);
+    }else{
+	printf("Not using any security mechanism.\n");
+    }
+}
+#endif
+
+static int
+sec_prot_internal(struct connectdata *conn, int level)
+{
+    int ret;
+    char *p;
+    unsigned int s = 1048576;
+    size_t nread;
+
+    if(!conn->sec_complete){
+      infof(conn->data, "No security data exchange has taken place.\n");
+      return -1;
+    }
+
+    if(level){
+      ftpsendf(conn->data->firstsocket, conn,
+               "PBSZ %u", s);
+      /* wait for feedback */
+      nread = GetLastResponse(conn->data->firstsocket,
+                              conn->data->buffer, conn);
+      if(nread < 0)
+        return /*CURLE_OPERATION_TIMEOUTED*/-1;
+      if(/*ret != COMPLETE*/conn->data->buffer[0] != '2'){
+        failf(conn->data, "Failed to set protection buffer size.\n");
+        return -1;
+      }
+      conn->buffer_size = s;
+      p = strstr(/*reply_string*/conn->data->buffer, "PBSZ=");
+      if(p)
+        sscanf(p, "PBSZ=%u", &s);
+      if(s < conn->buffer_size)
+        conn->buffer_size = s;
+    }
+
+    ftpsendf(conn->data->firstsocket, conn,
+             "PROT %c", level["CSEP"]);
+    /* wait for feedback */
+    nread = GetLastResponse(conn->data->firstsocket,
+			    conn->data->buffer, conn);
+    if(nread < 0)
+      return /*CURLE_OPERATION_TIMEOUTED*/-1;
+    if(/*ret != COMPLETE*/conn->data->buffer[0] != '2'){
+      failf(conn->data, "Failed to set protection level.\n");
+      return -1;
+    }
+    
+    conn->data_prot = (enum protection_level)level;
+    return 0;
+}
+
+enum protection_level
+set_command_prot(struct connectdata *conn, enum protection_level level)
+{
+    enum protection_level old = conn->command_prot;
+    conn->command_prot = level;
+    return old;
+}
+
+#if 0
+void
+sec_prot(int argc, char **argv)
+{
+    int level = -1;
+
+    if(argc < 2 || argc > 3)
+	goto usage;
+    if(!sec_complete) {
+	printf("No security data exchange has taken place.\n");
+	code = -1;
+	return;
+    }
+    level = name_to_level(argv[argc - 1]);
+    
+    if(level == -1)
+	goto usage;
+    
+    if((*mech->check_prot)(conn->app_data, level)) {
+	printf("%s does not implement %s protection.\n", 
+	       mech->name, level_to_name(level));
+	code = -1;
+	return;
+    }
+    
+    if(argc == 2 || strncasecmp(argv[1], "data", strlen(argv[1])) == 0) {
+	if(sec_prot_internal(level) < 0){
+	    code = -1;
+	    return;
+	}
+    } else if(strncasecmp(argv[1], "command", strlen(argv[1])) == 0)
+	set_command_prot(level);
+    else
+	goto usage;
+    code = 0;
+    return;
+ usage:
+    printf("usage: %s [command|data] [clear|safe|confidential|private]\n",
+	   argv[0]);
+    code = -1;
+}
+#endif
+
+void
+sec_set_protection_level(struct connectdata *conn)
+{
+  if(conn->sec_complete && conn->data_prot != conn->request_data_prot)
+    sec_prot_internal(conn, conn->request_data_prot);
+}
+
+
+int
+sec_request_prot(struct connectdata *conn, char *level)
+{
+  int l = name_to_level(level);
+  if(l == -1)
+    return -1;
+  conn->request_data_prot = (enum protection_level)l;
+  return 0;
+}
+
+int
+sec_login(struct connectdata *conn)
+{
+    int ret;
+    struct sec_client_mech **m;
+    size_t nread;
+    struct UrlData *data=conn->data;
+
+    for(m = mechs; *m && (*m)->name; m++) {
+	void *tmp;
+
+	tmp = realloc(conn->app_data, (*m)->size);
+	if (tmp == NULL) {
+          failf (data, "realloc %u failed", (*m)->size);
+          return -1;
+	}
+	conn->app_data = tmp;
+	    
+	if((*m)->init && (*(*m)->init)(conn->app_data) != 0) {
+	    infof(data, "Skipping %s...\n", (*m)->name);
+	    continue;
+	}
+	infof(data, "Trying %s...\n", (*m)->name);
+	/*ret = command("AUTH %s", (*m)->name);***/
+	ftpsendf(conn->data->firstsocket, conn,
+                 "AUTH %s", (*m)->name);
+	/* wait for feedback */
+	nread = GetLastResponse(conn->data->firstsocket,
+				conn->data->buffer, conn);
+	if(nread < 0)
+	    return /*CURLE_OPERATION_TIMEOUTED*/-1;
+	if(/*ret != CONTINUE*/conn->data->buffer[0] != '3'){
+	    if(/*code == 504*/strncmp(conn->data->buffer,"504",3) == 0) {
+		infof(data,
+                      "%s is not supported by the server.\n", (*m)->name);
+	    }
+            else if(/*code == 534*/strncmp(conn->data->buffer,"534",3) == 0) {
+              infof(data, "%s rejected as security mechanism.\n", (*m)->name);
+	    }
+            else if(/*ret == ERROR*/conn->data->buffer[0] == '5') {
+              infof(data, "The server doesn't support the FTP "
+                    "security extensions.\n");
+              return -1;
+	    }
+	    continue;
+	}
+
+	ret = (*(*m)->auth)(conn->app_data, /*host***/conn);
+	
+	if(ret == AUTH_CONTINUE)
+          continue;
+	else if(ret != AUTH_OK){
+          /* mechanism is supposed to output error string */
+	    return -1;
+	}
+	mech = *m;
+	conn->sec_complete = 1;
+	conn->command_prot = prot_safe;
+	break;
+    }
+    
+    return *m == NULL;
+}
+
+void
+sec_end(struct connectdata *conn)
+{
+    if (mech != NULL) {
+	if(mech->end)
+	    (*mech->end)(conn->app_data);
+	memset(conn->app_data, 0, mech->size);
+	free(conn->app_data);
+	conn->app_data = NULL;
+    }
+    conn->sec_complete = 0;
+    conn->data_prot = (enum protection_level)0;
+}
+
+#endif /* FTP_SERVER */
+
+#endif /* KRB4 */