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Diffstat (limited to 'lib/krb5.c')
| -rw-r--r-- | lib/krb5.c | 341 |
1 files changed, 341 insertions, 0 deletions
diff --git a/lib/krb5.c b/lib/krb5.c new file mode 100644 index 000000000..c51041dda --- /dev/null +++ b/lib/krb5.c @@ -0,0 +1,341 @@ +/* GSSAPI/krb5 support for FTP - loosely based on old krb4.c + * + * Copyright (c) 1995, 1996, 1997, 1998, 1999 Kungliga Tekniska Högskolan + * (Royal Institute of Technology, Stockholm, Sweden). + * Copyright (c) 2004 - 2012 Daniel Stenberg + * 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" + +#ifndef CURL_DISABLE_FTP +#ifdef HAVE_GSSAPI + +#ifdef HAVE_OLD_GSSMIT +#define GSS_C_NT_HOSTBASED_SERVICE gss_nt_service_name +#define NCOMPAT 1 +#endif + +#ifdef HAVE_NETDB_H +#include <netdb.h> +#endif + +#include "urldata.h" +#include "curl_base64.h" +#include "ftp.h" +#include "curl_gssapi.h" +#include "sendf.h" +#include "krb4.h" +#include "curl_memory.h" +#include "warnless.h" + +#define _MPRINTF_REPLACE /* use our functions only */ +#include <curl/mprintf.h> + +/* The last #include file should be: */ +#include "memdebug.h" + +#define LOCAL_ADDR (&conn->local_addr) +#define REMOTE_ADDR conn->ip_addr->ai_addr + +static int +krb5_init(void *app_data) +{ + gss_ctx_id_t *context = app_data; + /* Make sure our context is initialized for krb5_end. */ + *context = GSS_C_NO_CONTEXT; + return 0; +} + +static int +krb5_check_prot(void *app_data, int level) +{ + (void)app_data; /* unused */ + if(level == PROT_CONFIDENTIAL) + return -1; + return 0; +} + +static int +krb5_decode(void *app_data, void *buf, int len, + int level UNUSED_PARAM, + struct connectdata *conn UNUSED_PARAM) +{ + gss_ctx_id_t *context = app_data; + OM_uint32 maj, min; + gss_buffer_desc enc, dec; + + (void)level; + (void)conn; + + enc.value = buf; + enc.length = len; + maj = gss_unseal(&min, *context, &enc, &dec, NULL, NULL); + if(maj != GSS_S_COMPLETE) { + if(len >= 4) + strcpy(buf, "599 "); + return -1; + } + + memcpy(buf, dec.value, dec.length); + len = curlx_uztosi(dec.length); + gss_release_buffer(&min, &dec); + + return len; +} + +static int +krb5_overhead(void *app_data, int level, int len) +{ + /* no arguments are used */ + (void)app_data; + (void)level; + (void)len; + return 0; +} + +static int +krb5_encode(void *app_data, const void *from, int length, int level, void **to, + struct connectdata *conn UNUSED_PARAM) +{ + gss_ctx_id_t *context = app_data; + gss_buffer_desc dec, enc; + OM_uint32 maj, min; + int state; + int len; + + /* shut gcc up */ + conn = NULL; + + /* NOTE that the cast is safe, neither of the krb5, gnu gss and heimdal + * libraries modify the input buffer in gss_seal() + */ + dec.value = (void*)from; + dec.length = length; + maj = gss_seal(&min, *context, + level == PROT_PRIVATE, + GSS_C_QOP_DEFAULT, + &dec, &state, &enc); + + if(maj != GSS_S_COMPLETE) + return -1; + + /* malloc a new buffer, in case gss_release_buffer doesn't work as + expected */ + *to = malloc(enc.length); + if(!*to) + return -1; + memcpy(*to, enc.value, enc.length); + len = curlx_uztosi(enc.length); + gss_release_buffer(&min, &enc); + return len; +} + +static int +krb5_auth(void *app_data, struct connectdata *conn) +{ + int ret = AUTH_OK; + char *p; + const char *host = conn->host.name; + ssize_t nread; + curl_socklen_t l = sizeof(conn->local_addr); + struct SessionHandle *data = conn->data; + CURLcode result; + const char *service = "ftp", *srv_host = "host"; + gss_buffer_desc input_buffer, output_buffer, _gssresp, *gssresp; + OM_uint32 maj, min; + gss_name_t gssname; + gss_ctx_id_t *context = app_data; + struct gss_channel_bindings_struct chan; + size_t base64_sz = 0; + + if(getsockname(conn->sock[FIRSTSOCKET], + (struct sockaddr *)LOCAL_ADDR, &l) < 0) + perror("getsockname()"); + + chan.initiator_addrtype = GSS_C_AF_INET; + chan.initiator_address.length = l - 4; + chan.initiator_address.value = + &((struct sockaddr_in *)LOCAL_ADDR)->sin_addr.s_addr; + chan.acceptor_addrtype = GSS_C_AF_INET; + chan.acceptor_address.length = l - 4; + chan.acceptor_address.value = + &((struct sockaddr_in *)REMOTE_ADDR)->sin_addr.s_addr; + chan.application_data.length = 0; + chan.application_data.value = NULL; + + /* this loop will execute twice (once for service, once for host) */ + for(;;) { + /* this really shouldn't be repeated here, but can't help it */ + if(service == srv_host) { + result = Curl_ftpsendf(conn, "AUTH GSSAPI"); + + if(result) + return -2; + if(Curl_GetFTPResponse(&nread, conn, NULL)) + return -1; + + if(data->state.buffer[0] != '3') + return -1; + } + + input_buffer.value = data->state.buffer; + input_buffer.length = snprintf(input_buffer.value, BUFSIZE, "%s@%s", + service, host); + maj = gss_import_name(&min, &input_buffer, GSS_C_NT_HOSTBASED_SERVICE, + &gssname); + if(maj != GSS_S_COMPLETE) { + gss_release_name(&min, &gssname); + if(service == srv_host) { + Curl_failf(data, "Error importing service name %s", + input_buffer.value); + return AUTH_ERROR; + } + service = srv_host; + continue; + } + /* We pass NULL as |output_name_type| to avoid a leak. */ + gss_display_name(&min, gssname, &output_buffer, NULL); + Curl_infof(data, "Trying against %s\n", output_buffer.value); + gssresp = GSS_C_NO_BUFFER; + *context = GSS_C_NO_CONTEXT; + + do { + /* Release the buffer at each iteration to avoid leaking: the first time + we are releasing the memory from gss_display_name. The last item is + taken care by a final gss_release_buffer. */ + gss_release_buffer(&min, &output_buffer); + ret = AUTH_OK; + maj = Curl_gss_init_sec_context(data, + &min, + context, + gssname, + &chan, + gssresp, + &output_buffer, + NULL); + + if(gssresp) { + free(_gssresp.value); + gssresp = NULL; + } + + if(GSS_ERROR(maj)) { + Curl_infof(data, "Error creating security context\n"); + ret = AUTH_ERROR; + break; + } + + if(output_buffer.length != 0) { + result = Curl_base64_encode(data, (char *)output_buffer.value, + output_buffer.length, &p, &base64_sz); + if(result) { + Curl_infof(data,"base64-encoding: %s\n", curl_easy_strerror(result)); + ret = AUTH_CONTINUE; + break; + } + + result = Curl_ftpsendf(conn, "ADAT %s", p); + + free(p); + + if(result) { + ret = -2; + break; + } + + if(Curl_GetFTPResponse(&nread, conn, NULL)) { + ret = -1; + break; + } + + if(data->state.buffer[0] != '2' && data->state.buffer[0] != '3') { + Curl_infof(data, "Server didn't accept auth data\n"); + ret = AUTH_ERROR; + break; + } + + p = data->state.buffer + 4; + p = strstr(p, "ADAT="); + if(p) { + result = Curl_base64_decode(p + 5, + (unsigned char **)&_gssresp.value, + &_gssresp.length); + if(result) { + Curl_failf(data,"base64-decoding: %s", curl_easy_strerror(result)); + ret = AUTH_CONTINUE; + break; + } + } + + gssresp = &_gssresp; + } + } while(maj == GSS_S_CONTINUE_NEEDED); + + gss_release_name(&min, &gssname); + gss_release_buffer(&min, &output_buffer); + + if(gssresp) + free(_gssresp.value); + + if(ret == AUTH_OK || service == srv_host) + return ret; + + service = srv_host; + } + return ret; +} + +static void krb5_end(void *app_data) +{ + OM_uint32 min; + gss_ctx_id_t *context = app_data; + if(*context != GSS_C_NO_CONTEXT) { +#ifdef DEBUGBUILD + OM_uint32 maj = +#endif + gss_delete_sec_context(&min, context, GSS_C_NO_BUFFER); + DEBUGASSERT(maj == GSS_S_COMPLETE); + } +} + +struct Curl_sec_client_mech Curl_krb5_client_mech = { + "GSSAPI", + sizeof(gss_ctx_id_t), + krb5_init, + krb5_auth, + krb5_end, + krb5_check_prot, + krb5_overhead, + krb5_encode, + krb5_decode +}; + +#endif /* HAVE_GSSAPI */ +#endif /* CURL_DISABLE_FTP */ |