diff options
Diffstat (limited to 'libcurl/src/lib/security.c')
| -rw-r--r-- | libcurl/src/lib/security.c | 597 |
1 files changed, 597 insertions, 0 deletions
diff --git a/libcurl/src/lib/security.c b/libcurl/src/lib/security.c new file mode 100644 index 0000000..10cb73c --- /dev/null +++ b/libcurl/src/lib/security.c @@ -0,0 +1,597 @@ +/* This source code was modified by Martin Hedenfalk <mhe@stacken.kth.se> for
+ * use in Curl. His latest changes were done 2000-09-18.
+ *
+ * It has since been patched and modified a lot by Daniel Stenberg
+ * <daniel@haxx.se> to make it better applied to curl conditions, and to make
+ * it not use globals, pollute name space and more. This source code awaits a
+ * rewrite to work around the paragraph 2 in the BSD licenses as explained
+ * below.
+ *
+ * Copyright (c) 1998, 1999 Kungliga Tekniska Högskolan
+ * (Royal Institute of Technology, Stockholm, Sweden).
+ *
+ * Copyright (C) 2001 - 2015, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * 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 "curl_setup.h"
+
+#ifndef CURL_DISABLE_FTP
+#ifdef HAVE_GSSAPI
+
+#ifdef HAVE_NETDB_H
+#include <netdb.h>
+#endif
+
+#ifdef HAVE_LIMITS_H
+#include <limits.h>
+#endif
+
+#include "urldata.h"
+#include "curl_base64.h"
+#include "curl_memory.h"
+#include "curl_sec.h"
+#include "ftp.h"
+#include "sendf.h"
+#include "rawstr.h"
+#include "warnless.h"
+
+/* The last #include file should be: */
+#include "memdebug.h"
+
+static const struct {
+ enum protection_level level;
+ const char *name;
+} level_names[] = {
+ { PROT_CLEAR, "clear" },
+ { PROT_SAFE, "safe" },
+ { PROT_CONFIDENTIAL, "confidential" },
+ { PROT_PRIVATE, "private" }
+};
+
+static enum protection_level
+name_to_level(const char *name)
+{
+ int i;
+ for(i = 0; i < (int)sizeof(level_names)/(int)sizeof(level_names[0]); i++)
+ if(checkprefix(name, level_names[i].name))
+ return level_names[i].level;
+ return PROT_NONE;
+}
+
+/* Convert a protocol |level| to its char representation.
+ We take an int to catch programming mistakes. */
+static char level_to_char(int level) {
+ switch(level) {
+ case PROT_CLEAR:
+ return 'C';
+ case PROT_SAFE:
+ return 'S';
+ case PROT_CONFIDENTIAL:
+ return 'E';
+ case PROT_PRIVATE:
+ return 'P';
+ case PROT_CMD:
+ /* Fall through */
+ default:
+ /* Those 2 cases should not be reached! */
+ break;
+ }
+ DEBUGASSERT(0);
+ /* Default to the most secure alternative. */
+ return 'P';
+}
+
+static const struct Curl_sec_client_mech * const mechs[] = {
+#ifdef HAVE_GSSAPI
+ &Curl_krb5_client_mech,
+#endif
+ NULL
+};
+
+/* Send an FTP command defined by |message| and the optional arguments. The
+ function returns the ftp_code. If an error occurs, -1 is returned. */
+static int ftp_send_command(struct connectdata *conn, const char *message, ...)
+{
+ int ftp_code;
+ ssize_t nread=0;
+ va_list args;
+ char print_buffer[50];
+
+ va_start(args, message);
+ vsnprintf(print_buffer, sizeof(print_buffer), message, args);
+ va_end(args);
+
+ if(Curl_ftpsendf(conn, print_buffer)) {
+ ftp_code = -1;
+ }
+ else {
+ if(Curl_GetFTPResponse(&nread, conn, &ftp_code))
+ ftp_code = -1;
+ }
+
+ (void)nread; /* Unused */
+ return ftp_code;
+}
+
+/* Read |len| from the socket |fd| and store it in |to|. Return a CURLcode
+ saying whether an error occurred or CURLE_OK if |len| was read. */
+static CURLcode
+socket_read(curl_socket_t fd, void *to, size_t len)
+{
+ char *to_p = to;
+ CURLcode result;
+ ssize_t nread;
+
+ while(len > 0) {
+ result = Curl_read_plain(fd, to_p, len, &nread);
+ if(!result) {
+ len -= nread;
+ to_p += nread;
+ }
+ else {
+ /* FIXME: We are doing a busy wait */
+ if(result == CURLE_AGAIN)
+ continue;
+ return result;
+ }
+ }
+ return CURLE_OK;
+}
+
+
+/* Write |len| bytes from the buffer |to| to the socket |fd|. Return a
+ CURLcode saying whether an error occurred or CURLE_OK if |len| was
+ written. */
+static CURLcode
+socket_write(struct connectdata *conn, curl_socket_t fd, const void *to,
+ size_t len)
+{
+ const char *to_p = to;
+ CURLcode result;
+ ssize_t written;
+
+ while(len > 0) {
+ result = Curl_write_plain(conn, fd, to_p, len, &written);
+ if(!result) {
+ len -= written;
+ to_p += written;
+ }
+ else {
+ /* FIXME: We are doing a busy wait */
+ if(result == CURLE_AGAIN)
+ continue;
+ return result;
+ }
+ }
+ return CURLE_OK;
+}
+
+static CURLcode read_data(struct connectdata *conn,
+ curl_socket_t fd,
+ struct krb5buffer *buf)
+{
+ int len;
+ void* tmp;
+ CURLcode result;
+
+ result = socket_read(fd, &len, sizeof(len));
+ if(result)
+ return result;
+
+ len = ntohl(len);
+ tmp = realloc(buf->data, len);
+ if(tmp == NULL)
+ return CURLE_OUT_OF_MEMORY;
+
+ buf->data = tmp;
+ result = socket_read(fd, buf->data, len);
+ if(result)
+ return result;
+ buf->size = conn->mech->decode(conn->app_data, buf->data, len,
+ conn->data_prot, conn);
+ buf->index = 0;
+ return CURLE_OK;
+}
+
+static size_t
+buffer_read(struct krb5buffer *buf, void *data, size_t len)
+{
+ if(buf->size - buf->index < len)
+ len = buf->size - buf->index;
+ memcpy(data, (char*)buf->data + buf->index, len);
+ buf->index += len;
+ return len;
+}
+
+/* Matches Curl_recv signature */
+static ssize_t sec_recv(struct connectdata *conn, int sockindex,
+ char *buffer, size_t len, CURLcode *err)
+{
+ size_t bytes_read;
+ size_t total_read = 0;
+ curl_socket_t fd = conn->sock[sockindex];
+
+ *err = CURLE_OK;
+
+ /* Handle clear text response. */
+ if(conn->sec_complete == 0 || conn->data_prot == PROT_CLEAR)
+ return read(fd, buffer, len);
+
+ if(conn->in_buffer.eof_flag) {
+ conn->in_buffer.eof_flag = 0;
+ return 0;
+ }
+
+ bytes_read = buffer_read(&conn->in_buffer, buffer, len);
+ len -= bytes_read;
+ total_read += bytes_read;
+ buffer += bytes_read;
+
+ while(len > 0) {
+ if(read_data(conn, fd, &conn->in_buffer))
+ return -1;
+ if(conn->in_buffer.size == 0) {
+ if(bytes_read > 0)
+ conn->in_buffer.eof_flag = 1;
+ return bytes_read;
+ }
+ bytes_read = buffer_read(&conn->in_buffer, buffer, len);
+ len -= bytes_read;
+ total_read += bytes_read;
+ buffer += bytes_read;
+ }
+ /* FIXME: Check for overflow */
+ return total_read;
+}
+
+/* Send |length| bytes from |from| to the |fd| socket taking care of encoding
+ and negociating with the server. |from| can be NULL. */
+/* FIXME: We don't check for errors nor report any! */
+static void do_sec_send(struct connectdata *conn, curl_socket_t fd,
+ const char *from, int length)
+{
+ int bytes, htonl_bytes; /* 32-bit integers for htonl */
+ char *buffer = NULL;
+ char *cmd_buffer;
+ size_t cmd_size = 0;
+ CURLcode error;
+ enum protection_level prot_level = conn->data_prot;
+ bool iscmd = (prot_level == PROT_CMD)?TRUE:FALSE;
+
+ DEBUGASSERT(prot_level > PROT_NONE && prot_level < PROT_LAST);
+
+ if(iscmd) {
+ if(!strncmp(from, "PASS ", 5) || !strncmp(from, "ACCT ", 5))
+ prot_level = PROT_PRIVATE;
+ else
+ prot_level = conn->command_prot;
+ }
+ bytes = conn->mech->encode(conn->app_data, from, length, prot_level,
+ (void**)&buffer);
+ if(!buffer || bytes <= 0)
+ return; /* error */
+
+ if(iscmd) {
+ error = Curl_base64_encode(conn->data, buffer, curlx_sitouz(bytes),
+ &cmd_buffer, &cmd_size);
+ if(error) {
+ free(buffer);
+ return; /* error */
+ }
+ if(cmd_size > 0) {
+ static const char *enc = "ENC ";
+ static const char *mic = "MIC ";
+ if(prot_level == PROT_PRIVATE)
+ socket_write(conn, fd, enc, 4);
+ else
+ socket_write(conn, fd, mic, 4);
+
+ socket_write(conn, fd, cmd_buffer, cmd_size);
+ socket_write(conn, fd, "\r\n", 2);
+ infof(conn->data, "Send: %s%s\n", prot_level == PROT_PRIVATE?enc:mic,
+ cmd_buffer);
+ free(cmd_buffer);
+ }
+ }
+ else {
+ htonl_bytes = htonl(bytes);
+ socket_write(conn, fd, &htonl_bytes, sizeof(htonl_bytes));
+ socket_write(conn, fd, buffer, curlx_sitouz(bytes));
+ }
+ free(buffer);
+}
+
+static ssize_t sec_write(struct connectdata *conn, curl_socket_t fd,
+ const char *buffer, size_t length)
+{
+ ssize_t tx = 0, len = conn->buffer_size;
+
+ len -= conn->mech->overhead(conn->app_data, conn->data_prot,
+ curlx_sztosi(len));
+ if(len <= 0)
+ len = length;
+ while(length) {
+ if(length < (size_t)len)
+ len = length;
+
+ do_sec_send(conn, fd, buffer, curlx_sztosi(len));
+ length -= len;
+ buffer += len;
+ tx += len;
+ }
+ return tx;
+}
+
+/* Matches Curl_send signature */
+static ssize_t sec_send(struct connectdata *conn, int sockindex,
+ const void *buffer, size_t len, CURLcode *err)
+{
+ curl_socket_t fd = conn->sock[sockindex];
+ *err = CURLE_OK;
+ return sec_write(conn, fd, buffer, len);
+}
+
+CURL_STATIC int Curl_sec_read_msg(struct connectdata *conn, char *buffer,
+ enum protection_level level)
+{
+ /* decoded_len should be size_t or ssize_t but conn->mech->decode returns an
+ int */
+ int decoded_len;
+ char *buf;
+ int ret_code;
+ size_t decoded_sz = 0;
+ CURLcode error;
+
+ DEBUGASSERT(level > PROT_NONE && level < PROT_LAST);
+
+ error = Curl_base64_decode(buffer + 4, (unsigned char **)&buf, &decoded_sz);
+ if(error || decoded_sz == 0)
+ return -1;
+
+ if(decoded_sz > (size_t)INT_MAX) {
+ free(buf);
+ return -1;
+ }
+ decoded_len = curlx_uztosi(decoded_sz);
+
+ decoded_len = conn->mech->decode(conn->app_data, buf, decoded_len,
+ level, conn);
+ if(decoded_len <= 0) {
+ free(buf);
+ return -1;
+ }
+
+ if(conn->data->set.verbose) {
+ buf[decoded_len] = '\n';
+ Curl_debug(conn->data, CURLINFO_HEADER_IN, buf, decoded_len + 1, conn);
+ }
+
+ buf[decoded_len] = '\0';
+ DEBUGASSERT(decoded_len > 3);
+ if(buf[3] == '-')
+ ret_code = 0;
+ else {
+ /* Check for error? */
+ (void)sscanf(buf, "%d", &ret_code);
+ }
+
+ if(buf[decoded_len - 1] == '\n')
+ buf[decoded_len - 1] = '\0';
+ /* FIXME: Is |buffer| length always greater than |decoded_len|? */
+ strcpy(buffer, buf);
+ free(buf);
+ return ret_code;
+}
+
+/* FIXME: The error code returned here is never checked. */
+static int sec_set_protection_level(struct connectdata *conn)
+{
+ int code;
+ char* pbsz;
+ static unsigned int buffer_size = 1 << 20; /* 1048576 */
+ enum protection_level level = conn->request_data_prot;
+
+ DEBUGASSERT(level > PROT_NONE && level < PROT_LAST);
+
+ if(!conn->sec_complete) {
+ infof(conn->data, "Trying to change the protection level after the"
+ "completion of the data exchange.\n");
+ return -1;
+ }
+
+ /* Bail out if we try to set up the same level */
+ if(conn->data_prot == level)
+ return 0;
+
+ if(level) {
+ code = ftp_send_command(conn, "PBSZ %u", buffer_size);
+ if(code < 0)
+ return -1;
+
+ if(code/100 != 2) {
+ failf(conn->data, "Failed to set the protection's buffer size.");
+ return -1;
+ }
+ conn->buffer_size = buffer_size;
+
+ pbsz = strstr(conn->data->state.buffer, "PBSZ=");
+ if(pbsz) {
+ /* FIXME: Checks for errors in sscanf? */
+ sscanf(pbsz, "PBSZ=%u", &buffer_size);
+ if(buffer_size < conn->buffer_size)
+ conn->buffer_size = buffer_size;
+ }
+ }
+
+ /* Now try to negiociate the protection level. */
+ code = ftp_send_command(conn, "PROT %c", level_to_char(level));
+
+ if(code < 0)
+ return -1;
+
+ if(code/100 != 2) {
+ failf(conn->data, "Failed to set the protection level.");
+ return -1;
+ }
+
+ conn->data_prot = level;
+ if(level == PROT_PRIVATE)
+ conn->command_prot = level;
+
+ return 0;
+}
+
+CURL_STATIC int
+Curl_sec_request_prot(struct connectdata *conn, const char *level)
+{
+ enum protection_level l = name_to_level(level);
+ if(l == PROT_NONE)
+ return -1;
+ DEBUGASSERT(l > PROT_NONE && l < PROT_LAST);
+ conn->request_data_prot = l;
+ return 0;
+}
+
+static CURLcode choose_mech(struct connectdata *conn)
+{
+ int ret;
+ struct SessionHandle *data = conn->data;
+ const struct Curl_sec_client_mech * const *mech;
+ void *tmp_allocation;
+ const char *mech_name;
+
+ for(mech = mechs; (*mech); ++mech) {
+ mech_name = (*mech)->name;
+ /* We have no mechanism with a NULL name but keep this check */
+ DEBUGASSERT(mech_name != NULL);
+ if(mech_name == NULL) {
+ infof(data, "Skipping mechanism with empty name (%p)\n", (void *)mech);
+ continue;
+ }
+ tmp_allocation = realloc(conn->app_data, (*mech)->size);
+ if(tmp_allocation == NULL) {
+ failf(data, "Failed realloc of size %u", (*mech)->size);
+ mech = NULL;
+ return CURLE_OUT_OF_MEMORY;
+ }
+ conn->app_data = tmp_allocation;
+
+ if((*mech)->init) {
+ ret = (*mech)->init(conn->app_data);
+ if(ret != 0) {
+ infof(data, "Failed initialization for %s. Skipping it.\n", mech_name);
+ continue;
+ }
+ }
+
+ infof(data, "Trying mechanism %s...\n", mech_name);
+ ret = ftp_send_command(conn, "AUTH %s", mech_name);
+ if(ret < 0)
+ /* FIXME: This error is too generic but it is OK for now. */
+ return CURLE_COULDNT_CONNECT;
+
+ if(ret/100 != 3) {
+ switch(ret) {
+ case 504:
+ infof(data, "Mechanism %s is not supported by the server (server "
+ "returned ftp code: 504).\n", mech_name);
+ break;
+ case 534:
+ infof(data, "Mechanism %s was rejected by the server (server returned "
+ "ftp code: 534).\n", mech_name);
+ break;
+ default:
+ if(ret/100 == 5) {
+ infof(data, "server does not support the security extensions\n");
+ return CURLE_USE_SSL_FAILED;
+ }
+ break;
+ }
+ continue;
+ }
+
+ /* Authenticate */
+ ret = (*mech)->auth(conn->app_data, conn);
+
+ if(ret == AUTH_CONTINUE)
+ continue;
+ else if(ret != AUTH_OK) {
+ /* Mechanism has dumped the error to stderr, don't error here. */
+ return -1;
+ }
+ DEBUGASSERT(ret == AUTH_OK);
+
+ conn->mech = *mech;
+ conn->sec_complete = 1;
+ conn->recv[FIRSTSOCKET] = sec_recv;
+ conn->send[FIRSTSOCKET] = sec_send;
+ conn->recv[SECONDARYSOCKET] = sec_recv;
+ conn->send[SECONDARYSOCKET] = sec_send;
+ conn->command_prot = PROT_SAFE;
+ /* Set the requested protection level */
+ /* BLOCKING */
+ (void)sec_set_protection_level(conn);
+ break;
+ }
+
+ return *mech != NULL ? CURLE_OK : CURLE_FAILED_INIT;
+}
+
+CURL_STATIC CURLcode
+Curl_sec_login(struct connectdata *conn)
+{
+ return choose_mech(conn);
+}
+
+
+CURL_STATIC void
+Curl_sec_end(struct connectdata *conn)
+{
+ if(conn->mech != NULL && conn->mech->end)
+ conn->mech->end(conn->app_data);
+ free(conn->app_data);
+ conn->app_data = NULL;
+ if(conn->in_buffer.data) {
+ free(conn->in_buffer.data);
+ conn->in_buffer.data = NULL;
+ conn->in_buffer.size = 0;
+ conn->in_buffer.index = 0;
+ /* FIXME: Is this really needed? */
+ conn->in_buffer.eof_flag = 0;
+ }
+ conn->sec_complete = 0;
+ conn->data_prot = PROT_CLEAR;
+ conn->mech = NULL;
+}
+
+#endif /* HAVE_GSSAPI */
+
+#endif /* CURL_DISABLE_FTP */
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