Initial revision

svn path=/trunk/; revision=3068

diff --git a/gssapi.c b/gssapi.c
new file mode 100644 (file)
index 0000000..4b51cb4
--- /dev/null
+++ b/gssapi.c
@@ -0,0 +1,207 @@
+/*
+ * cram.c -- GSSAPI authentication (see RFC 1508)
+ *
+ * For license terms, see the file COPYING in this directory.
+ */
+
+#include  "config.h"
+#include  <stdio.h>
+#include  <string.h>
+#include  <ctype.h>
+#if defined(STDC_HEADERS)
+#include  <stdlib.h>
+#endif
+#include  "fetchmail.h"
+#include  "socket.h"
+
+#include  "i18n.h"
+#include "md5.h"
+
+#ifdef GSSAPI
+#  ifdef HAVE_GSSAPI_H
+#    include <gssapi.h>
+#  endif
+#  ifdef HAVE_GSSAPI_GSSAPI_H
+#    include <gssapi/gssapi.h>
+#  endif
+#  ifdef HAVE_GSSAPI_GSSAPI_GENERIC_H
+#    include <gssapi/gssapi_generic.h>
+#  endif
+#  ifndef HAVE_GSS_C_NT_HOSTBASED_SERVICE
+#    define GSS_C_NT_HOSTBASED_SERVICE gss_nt_service_name
+#  endif
+
+#define GSSAUTH_P_NONE      1
+#define GSSAUTH_P_INTEGRITY 2
+#define GSSAUTH_P_PRIVACY   4
+
+int do_gssauth(int sock, char *command, char *hostname, char *username)
+{
+    gss_buffer_desc request_buf, send_token;
+    gss_buffer_t sec_token;
+    gss_name_t target_name;
+    gss_ctx_id_t context;
+    gss_OID mech_name;
+    gss_qop_t quality;
+    int cflags;
+    OM_uint32 maj_stat, min_stat;
+    char buf1[8192], buf2[8192], server_conf_flags;
+    unsigned long buf_size;
+    int result;
+
+    /* first things first: get an imap ticket for host */
+    sprintf(buf1, "imap@%s", hostname);
+    request_buf.value = buf1;
+    request_buf.length = strlen(buf1) + 1;
+    maj_stat = gss_import_name(&min_stat, &request_buf, GSS_C_NT_HOSTBASED_SERVICE,
+        &target_name);
+    if (maj_stat != GSS_S_COMPLETE) {
+        report(stderr, _("Couldn't get service name for [%s]\n"), buf1);
+        return PS_AUTHFAIL;
+    }
+    else if (outlevel >= O_DEBUG) {
+        maj_stat = gss_display_name(&min_stat, target_name, &request_buf,
+            &mech_name);
+        report(stderr, _("Using service name [%s]\n"),request_buf.value);
+        maj_stat = gss_release_buffer(&min_stat, &request_buf);
+    }
+
+    gen_send(sock, "%s GSSAPI", command);
+
+    /* upon receipt of the GSSAPI authentication request, server returns
+     * null data ready response. */
+    if (result = gen_recv(sock, buf1, sizeof buf1)) {
+        return result;
+    }
+
+    /* now start the security context initialisation loop... */
+    sec_token = GSS_C_NO_BUFFER;
+    context = GSS_C_NO_CONTEXT;
+    if (outlevel >= O_VERBOSE)
+        report(stdout, _("Sending credentials\n"));
+    do {
+        send_token.length = 0;
+       send_token.value = NULL;
+        maj_stat = gss_init_sec_context(&min_stat, 
+                                       GSS_C_NO_CREDENTIAL,
+                                       &context, 
+                                       target_name, 
+                                       GSS_C_NO_OID, 
+                                       GSS_C_MUTUAL_FLAG | GSS_C_SEQUENCE_FLAG, 
+                                       0, 
+                                       GSS_C_NO_CHANNEL_BINDINGS, 
+                                       sec_token, 
+                                       NULL, 
+                                       &send_token, 
+                                       NULL, 
+                                       NULL);
+        if (maj_stat!=GSS_S_COMPLETE && maj_stat!=GSS_S_CONTINUE_NEEDED) {
+            report(stderr, _("Error exchanging credentials\n"));
+            gss_release_name(&min_stat, &target_name);
+            /* wake up server and await NO response */
+            SockWrite(sock, "\r\n", 2);
+            if (result = gen_recv(sock, buf1, sizeof buf1))
+                return result;
+            return PS_AUTHFAIL;
+        }
+        to64frombits(buf1, send_token.value, send_token.length);
+        gss_release_buffer(&min_stat, &send_token);
+       strcat(buf1, "\r\n");
+        SockWrite(sock, buf1, strlen(buf1));
+        if (outlevel >= O_MONITOR)
+            report(stdout, "IMAP> %s\n", buf1);
+        if (maj_stat == GSS_S_CONTINUE_NEEDED) {
+           if (result = gen_recv(sock, buf1, sizeof buf1)) {
+               gss_release_name(&min_stat, &target_name);
+               return result;
+           }
+           request_buf.length = from64tobits(buf2, buf1 + 2);
+           request_buf.value = buf2;
+           sec_token = &request_buf;
+        }
+    } while (maj_stat == GSS_S_CONTINUE_NEEDED);
+    gss_release_name(&min_stat, &target_name);
+
+    /* get security flags and buffer size */
+    if (result = gen_recv(sock, buf1, sizeof buf1)) {
+        return result;
+    }
+    request_buf.length = from64tobits(buf2, buf1 + 2);
+    request_buf.value = buf2;
+
+    maj_stat = gss_unwrap(&min_stat, context, &request_buf, &send_token,
+        &cflags, &quality);
+    if (maj_stat != GSS_S_COMPLETE) {
+        report(stderr, _("Couldn't unwrap security level data\n"));
+        gss_release_buffer(&min_stat, &send_token);
+        return PS_AUTHFAIL;
+    }
+    if (outlevel >= O_DEBUG)
+        report(stdout, _("Credential exchange complete\n"));
+    /* first octet is security levels supported. We want none, for now */
+    server_conf_flags = ((char *)send_token.value)[0];
+    if ( !(((char *)send_token.value)[0] & GSSAUTH_P_NONE) ) {
+        report(stderr, _("Server requires integrity and/or privacy\n"));
+        gss_release_buffer(&min_stat, &send_token);
+        return PS_AUTHFAIL;
+    }
+    ((char *)send_token.value)[0] = 0;
+    buf_size = ntohl(*((long *)send_token.value));
+    /* we don't care about buffer size if we don't wrap data */
+    gss_release_buffer(&min_stat, &send_token);
+    if (outlevel >= O_DEBUG) {
+        report(stdout, _("Unwrapped security level flags: %s%s%s\n"),
+            server_conf_flags & GSSAUTH_P_NONE ? "N" : "-",
+            server_conf_flags & GSSAUTH_P_INTEGRITY ? "I" : "-",
+            server_conf_flags & GSSAUTH_P_PRIVACY ? "C" : "-");
+        report(stdout, _("Maximum GSS token size is %ld\n"),buf_size);
+    }
+
+    /* now respond in kind (hack!!!) */
+    buf_size = htonl(buf_size); /* do as they do... only matters if we do enc */
+    memcpy(buf1, &buf_size, 4);
+    buf1[0] = GSSAUTH_P_NONE;
+    strcpy(buf1+4, username); /* server decides if princ is user */
+    request_buf.length = 4 + strlen(username) + 1;
+    request_buf.value = buf1;
+    maj_stat = gss_wrap(&min_stat, context, 0, GSS_C_QOP_DEFAULT, &request_buf,
+        &cflags, &send_token);
+    if (maj_stat != GSS_S_COMPLETE) {
+        report(stderr, _("Error creating security level request\n"));
+        return PS_AUTHFAIL;
+    }
+    to64frombits(buf1, send_token.value, send_token.length);
+    if (outlevel >= O_DEBUG) {
+        report(stdout, _("Requesting authorization as %s\n"), username);
+        report(stdout, "IMAP> %s\n",buf1);
+    }
+    strcat(buf1, "\r\n");
+    SockWrite(sock, buf1, strlen(buf1));
+
+    /* we should be done. Get status and finish up */
+    do {
+       if (result = gen_recv(sock, buf1, sizeof buf1))
+           return result;
+    } while(strncmp(buf1, tag, strlen(tag)) != 0);
+    if (strstr(buf1, "OK")) {
+        /* flush security context */
+        if (outlevel >= O_DEBUG)
+            report(stdout, _("Releasing GSS credentials\n"));
+        maj_stat = gss_delete_sec_context(&min_stat, &context, &send_token);
+        if (maj_stat != GSS_S_COMPLETE) {
+            report(stderr, _("Error releasing credentials\n"));
+            return PS_AUTHFAIL;
+        }
+        /* send_token may contain a notification to the server to flush
+         * credentials. RFC 1731 doesn't specify what to do, and since this
+         * support is only for authentication, we'll assume the server
+         * knows enough to flush its own credentials */
+        gss_release_buffer(&min_stat, &send_token);
+        return PS_SUCCESS;
+    }
+
+    return PS_AUTHFAIL;
+}      
+#endif /* GSSAPI */
+
+/* gssapi.c ends here */