aboutsummaryrefslogtreecommitdiffstats
path: root/lib/gssapi/mech/gss_aeap.c
blob: 6395d8442b8c066de4282373068d63341a3078cb (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
/*
 * AEAD support
 */

#include "mech_locl.h"

/**
 * Encrypts or sign the data.
 *
 * This is a more complicated version of gss_wrap(), it allows the
 * caller to use AEAD data (signed header/trailer) and allow greater
 * controll over where the encrypted data is placed.
 *
 * The maximum packet size is gss_context_stream_sizes.max_msg_size.
 *
 * The caller needs provide the folloing buffers when using in conf_req_flag=1 mode:
 *
 * - HEADER (of size gss_context_stream_sizes.header)
 *   { DATA or SIGN_ONLY } (optional, zero or more)
 *   PADDING (of size gss_context_stream_sizes.blocksize, if zero padding is zero, can be omitted)
 *   TRAILER (of size gss_context_stream_sizes.trailer)
 *
 * - on DCE-RPC mode, the caller can skip PADDING and TRAILER if the
 *   DATA elements is padded to a block bountry and header is of at
 *   least size gss_context_stream_sizes.header + gss_context_stream_sizes.trailer.
 *
 * HEADER, PADDING, TRAILER will be shrunken to the size required to transmit any of them too large.
 *
 * To generate gss_wrap() compatible packets, use: HEADER | DATA | PADDING | TRAILER
 *
 * When used in conf_req_flag=0,
 *
 * - HEADER (of size gss_context_stream_sizes.header)
 *   { DATA or SIGN_ONLY } (optional, zero or more)
 *   PADDING (of size gss_context_stream_sizes.blocksize, if zero padding is zero, can be omitted)
 *   TRAILER (of size gss_context_stream_sizes.trailer)
 *
 *
 * The input sizes of HEADER, PADDING and TRAILER can be fetched using gss_wrap_iov_length() or
 * gss_context_query_attributes().
 *
 * @ingroup gssapi
 */


GSSAPI_LIB_FUNCTION OM_uint32 GSSAPI_LIB_CALL
gss_wrap_iov(OM_uint32 * minor_status,
	     gss_ctx_id_t  context_handle,
	     int conf_req_flag,
	     gss_qop_t qop_req,
	     int * conf_state,
	     gss_iov_buffer_desc *iov,
	     int iov_count)
{
	struct _gss_context *ctx = (struct _gss_context *) context_handle;
	gssapi_mech_interface m;

	if (minor_status)
	    *minor_status = 0;
	if (conf_state)
	    *conf_state = 0;
	if (ctx == NULL)
	    return GSS_S_NO_CONTEXT;
	if (iov == NULL && iov_count != 0)
	    return GSS_S_CALL_INACCESSIBLE_READ;

	m = ctx->gc_mech;

	if (m->gm_wrap_iov == NULL)
	    return GSS_S_UNAVAILABLE;

	return (m->gm_wrap_iov)(minor_status, ctx->gc_ctx,
				conf_req_flag, qop_req, conf_state,
				iov, iov_count);
}

/**
 * Decrypt or verifies the signature on the data.
 *
 *
 * @ingroup gssapi
 */

GSSAPI_LIB_FUNCTION OM_uint32 GSSAPI_LIB_CALL
gss_unwrap_iov(OM_uint32 *minor_status,
	       gss_ctx_id_t context_handle,
	       int *conf_state,
	       gss_qop_t *qop_state,
	       gss_iov_buffer_desc *iov,
	       int iov_count)
{
	struct _gss_context *ctx = (struct _gss_context *) context_handle;
	gssapi_mech_interface m;

	if (minor_status)
	    *minor_status = 0;
	if (conf_state)
	    *conf_state = 0;
	if (qop_state)
	    *qop_state = 0;
	if (ctx == NULL)
	    return GSS_S_NO_CONTEXT;
	if (iov == NULL && iov_count != 0)
	    return GSS_S_CALL_INACCESSIBLE_READ;

	m = ctx->gc_mech;

	if (m->gm_unwrap_iov == NULL)
	    return GSS_S_UNAVAILABLE;

	return (m->gm_unwrap_iov)(minor_status, ctx->gc_ctx,
				  conf_state, qop_state,
				  iov, iov_count);
}

/**
 * Update the length fields in iov buffer for the types:
 * - GSS_IOV_BUFFER_TYPE_HEADER
 * - GSS_IOV_BUFFER_TYPE_PADDING
 * - GSS_IOV_BUFFER_TYPE_TRAILER
 *
 * Consider using gss_context_query_attributes() to fetch the data instead.
 *
 * @ingroup gssapi
 */

GSSAPI_LIB_FUNCTION OM_uint32 GSSAPI_LIB_CALL
gss_wrap_iov_length(OM_uint32 * minor_status,
		    gss_ctx_id_t context_handle,
		    int conf_req_flag,
		    gss_qop_t qop_req,
		    int *conf_state,
		    gss_iov_buffer_desc *iov,
		    int iov_count)
{
	struct _gss_context *ctx = (struct _gss_context *) context_handle;
	gssapi_mech_interface m;

	if (minor_status)
	    *minor_status = 0;
	if (conf_state)
	    *conf_state = 0;
	if (ctx == NULL)
	    return GSS_S_NO_CONTEXT;
	if (iov == NULL && iov_count != 0)
	    return GSS_S_CALL_INACCESSIBLE_READ;

	m = ctx->gc_mech;

	if (m->gm_wrap_iov_length == NULL)
	    return GSS_S_UNAVAILABLE;

	return (m->gm_wrap_iov_length)(minor_status, ctx->gc_ctx,
				       conf_req_flag, qop_req, conf_state,
				       iov, iov_count);
}

/**
 * Free all buffer allocated by gss_wrap_iov() or gss_unwrap_iov() by
 * looking at the GSS_IOV_BUFFER_FLAG_ALLOCATED flag.
 *
 * @ingroup gssapi
 */

GSSAPI_LIB_FUNCTION OM_uint32 GSSAPI_LIB_CALL
gss_release_iov_buffer(OM_uint32 *minor_status,
		       gss_iov_buffer_desc *iov,
		       int iov_count)
{
    OM_uint32 junk;
    int i;

    if (minor_status)
	*minor_status = 0;
    if (iov == NULL && iov_count != 0)
	return GSS_S_CALL_INACCESSIBLE_READ;

    for (i = 0; i < iov_count; i++) {
	if ((iov[i].type & GSS_IOV_BUFFER_FLAG_ALLOCATED) == 0)
	    continue;
	gss_release_buffer(&junk, &iov[i].buffer);
	iov[i].type &= ~GSS_IOV_BUFFER_FLAG_ALLOCATED;
    }
    return GSS_S_COMPLETE;
}

/**
 * Query the context for parameters.
 *
 * SSPI equivalent if this function is QueryContextAttributes.
 *
 * - GSS_C_ATTR_STREAM_SIZES data is a gss_context_stream_sizes.
 *
 * @ingroup gssapi
 */

gss_OID_desc GSSAPI_LIB_FUNCTION __gss_c_attr_stream_sizes_oid_desc =
    {10, rk_UNCONST("\x2a\x86\x48\x86\xf7\x12\x01\x02\x01\x03")};

GSSAPI_LIB_FUNCTION OM_uint32 GSSAPI_LIB_CALL
gss_context_query_attributes(OM_uint32 *minor_status,
			     gss_const_ctx_id_t context_handle,
			     const gss_OID attribute,
			     void *data,
			     size_t len)
{
    if (minor_status)
	*minor_status = 0;

    if (gss_oid_equal(GSS_C_ATTR_STREAM_SIZES, attribute)) {
	memset(data, 0, len);
	return GSS_S_COMPLETE;
    }

    return GSS_S_FAILURE;
}

/*
 * AEAD wrap API for a single piece of associated data, for compatibility
 * with MIT and as specified by draft-howard-gssapi-aead-00.txt.
 *
 * @ingroup gssapi
 */
GSSAPI_LIB_FUNCTION OM_uint32 GSSAPI_LIB_CALL
gss_wrap_aead(OM_uint32 *minor_status,
	      gss_ctx_id_t context_handle,
              int conf_req_flag,
              gss_qop_t qop_req,
              gss_buffer_t input_assoc_buffer,
              gss_buffer_t input_payload_buffer,
              int *conf_state,
              gss_buffer_t output_message_buffer)
{
    OM_uint32 major_status, tmp, flags = 0;
    gss_iov_buffer_desc iov[5];
    size_t i;
    unsigned char *p;

    memset(iov, 0, sizeof(iov));

    iov[0].type = GSS_IOV_BUFFER_TYPE_HEADER;

    iov[1].type = GSS_IOV_BUFFER_TYPE_SIGN_ONLY;
    if (input_assoc_buffer)
	iov[1].buffer = *input_assoc_buffer;

    iov[2].type = GSS_IOV_BUFFER_TYPE_DATA;
    if (input_payload_buffer)
	iov[2].buffer.length = input_payload_buffer->length;

    gss_inquire_context(minor_status, context_handle, NULL, NULL,
			NULL, NULL, &flags, NULL, NULL);

    /* krb5 mech rejects padding/trailer if DCE-style is set */
    iov[3].type = (flags & GSS_C_DCE_STYLE) ? GSS_IOV_BUFFER_TYPE_EMPTY
					    : GSS_IOV_BUFFER_TYPE_PADDING;
    iov[4].type = (flags & GSS_C_DCE_STYLE) ? GSS_IOV_BUFFER_TYPE_EMPTY
					    : GSS_IOV_BUFFER_TYPE_TRAILER;

    major_status = gss_wrap_iov_length(minor_status, context_handle,
				       conf_req_flag, qop_req, conf_state,
				       iov, 5);
    if (GSS_ERROR(major_status))
	return major_status;

    for (i = 0, output_message_buffer->length = 0; i < 5; i++) {
        if (GSS_IOV_BUFFER_TYPE(iov[i].type) == GSS_IOV_BUFFER_TYPE_SIGN_ONLY)
	    continue;

	output_message_buffer->length += iov[i].buffer.length;
    }

    output_message_buffer->value = malloc(output_message_buffer->length);
    if (output_message_buffer->value == NULL) {
	*minor_status = ENOMEM;
	return GSS_S_FAILURE;
    }

    for (i = 0, p = output_message_buffer->value; i < 5; i++) {
	if (GSS_IOV_BUFFER_TYPE(iov[i].type) == GSS_IOV_BUFFER_TYPE_SIGN_ONLY)
	    continue;
	else if (GSS_IOV_BUFFER_TYPE(iov[i].type) == GSS_IOV_BUFFER_TYPE_DATA)
	    memcpy(p, input_payload_buffer->value, input_payload_buffer->length);

	iov[i].buffer.value = p;
	p += iov[i].buffer.length;
    }

    major_status = gss_wrap_iov(minor_status, context_handle, conf_req_flag,
				qop_req, conf_state, iov, 5);
    if (GSS_ERROR(major_status))
        gss_release_buffer(&tmp, output_message_buffer);

    return major_status;
}

/*
 * AEAD unwrap for a single piece of associated data, for compatibility
 * with MIT and as specified by draft-howard-gssapi-aead-00.txt.
 *
 * @ingroup gssapi
 */
GSSAPI_LIB_FUNCTION OM_uint32 GSSAPI_LIB_CALL
gss_unwrap_aead(OM_uint32 *minor_status,
		gss_ctx_id_t context_handle,
		gss_buffer_t input_message_buffer,
		gss_buffer_t input_assoc_buffer,
		gss_buffer_t output_payload_buffer,
		int *conf_state,
		gss_qop_t *qop_state)
{
    OM_uint32 major_status, tmp;
    gss_iov_buffer_desc iov[3];

    memset(iov, 0, sizeof(iov));

    iov[0].type = GSS_IOV_BUFFER_TYPE_STREAM;
    iov[0].buffer = *input_message_buffer;

    iov[1].type = GSS_IOV_BUFFER_TYPE_SIGN_ONLY;
    if (input_assoc_buffer)
	iov[1].buffer = *input_assoc_buffer;

    iov[2].type = GSS_IOV_BUFFER_TYPE_DATA | GSS_IOV_BUFFER_FLAG_ALLOCATE;

    major_status = gss_unwrap_iov(minor_status, context_handle, conf_state,
				  qop_state, iov, 3);
    if (GSS_ERROR(major_status))
	gss_release_iov_buffer(&tmp, &iov[2], 1);
    else
	*output_payload_buffer = iov[2].buffer;

    return major_status;
}