/src/mbedtls/library/asn1parse.c

Source (jump to first uncovered line)
/*
 *  Generic ASN.1 parsing
 *
 *  Copyright The Mbed TLS Contributors
 *  SPDX-License-Identifier: Apache-2.0
 *
 *  Licensed under the Apache License, Version 2.0 (the "License"); you may
 *  not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

#include "common.h"

#if defined(MBEDTLS_ASN1_PARSE_C)

#include "mbedtls/asn1.h"
#include "mbedtls/platform_util.h"
#include "mbedtls/error.h"

#include <string.h>

#if defined(MBEDTLS_BIGNUM_C)
#include "mbedtls/bignum.h"
#endif

#include "mbedtls/platform.h"

/*
 * ASN.1 DER decoding routines
 */
int mbedtls_asn1_get_len(unsigned char **p,
                         const unsigned char *end,
                         size_t *len)
{
    if ((end - *p) < 1) {
        return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
    }

    if ((**p & 0x80) == 0) {
        *len = *(*p)++;
    } else {
        switch (**p & 0x7F) {
            case 1:
                if ((end - *p) < 2) {
                    return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
                }

                *len = (*p)[1];
                (*p) += 2;
                break;

            case 2:
                if ((end - *p) < 3) {
                    return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
                }

                *len = ((size_t) (*p)[1] << 8) | (*p)[2];
                (*p) += 3;
                break;

            case 3:
                if ((end - *p) < 4) {
                    return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
                }

                *len = ((size_t) (*p)[1] << 16) |
                       ((size_t) (*p)[2] << 8) | (*p)[3];
                (*p) += 4;
                break;

            case 4:
                if ((end - *p) < 5) {
                    return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
                }

                *len = ((size_t) (*p)[1] << 24) | ((size_t) (*p)[2] << 16) |
                       ((size_t) (*p)[3] << 8) |           (*p)[4];
                (*p) += 5;
                break;

            default:
                return MBEDTLS_ERR_ASN1_INVALID_LENGTH;
        }
    }

    if (*len > (size_t) (end - *p)) {
        return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
    }

    return 0;
}

int mbedtls_asn1_get_tag(unsigned char **p,
                         const unsigned char *end,
                         size_t *len, int tag)
{
    if ((end - *p) < 1) {
        return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
    }

    if (**p != tag) {
        return MBEDTLS_ERR_ASN1_UNEXPECTED_TAG;
    }

    (*p)++;

    return mbedtls_asn1_get_len(p, end, len);
}

int mbedtls_asn1_get_bool(unsigned char **p,
                          const unsigned char *end,
                          int *val)
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    size_t len;

    if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_BOOLEAN)) != 0) {
        return ret;
    }

    if (len != 1) {
        return MBEDTLS_ERR_ASN1_INVALID_LENGTH;
    }

    *val = (**p != 0) ? 1 : 0;
    (*p)++;

    return 0;
}

static int asn1_get_tagged_int(unsigned char **p,
                               const unsigned char *end,
                               int tag, int *val)
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    size_t len;

    if ((ret = mbedtls_asn1_get_tag(p, end, &len, tag)) != 0) {
        return ret;
    }

    /*
     * len==0 is malformed (0 must be represented as 020100 for INTEGER,
     * or 0A0100 for ENUMERATED tags
     */
    if (len == 0) {
        return MBEDTLS_ERR_ASN1_INVALID_LENGTH;
    }
    /* This is a cryptography library. Reject negative integers. */
    if ((**p & 0x80) != 0) {
        return MBEDTLS_ERR_ASN1_INVALID_LENGTH;
    }

    /* Skip leading zeros. */
    while (len > 0 && **p == 0) {
        ++(*p);
        --len;
    }

    /* Reject integers that don't fit in an int. This code assumes that
     * the int type has no padding bit. */
    if (len > sizeof(int)) {
        return MBEDTLS_ERR_ASN1_INVALID_LENGTH;
    }
    if (len == sizeof(int) && (**p & 0x80) != 0) {
        return MBEDTLS_ERR_ASN1_INVALID_LENGTH;
    }

    *val = 0;
    while (len-- > 0) {
        *val = (*val << 8) | **p;
        (*p)++;
    }

    return 0;
}

int mbedtls_asn1_get_int(unsigned char **p,
                         const unsigned char *end,
                         int *val)
{
    return asn1_get_tagged_int(p, end, MBEDTLS_ASN1_INTEGER, val);
}

int mbedtls_asn1_get_enum(unsigned char **p,
                          const unsigned char *end,
                          int *val)
{
    return asn1_get_tagged_int(p, end, MBEDTLS_ASN1_ENUMERATED, val);
}

#if defined(MBEDTLS_BIGNUM_C)
int mbedtls_asn1_get_mpi(unsigned char **p,
                         const unsigned char *end,
                         mbedtls_mpi *X)
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    size_t len;

    if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_INTEGER)) != 0) {
        return ret;
    }

    ret = mbedtls_mpi_read_binary(X, *p, len);

    *p += len;

    return ret;
}
#endif /* MBEDTLS_BIGNUM_C */

int mbedtls_asn1_get_bitstring(unsigned char **p, const unsigned char *end,
                               mbedtls_asn1_bitstring *bs)
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;

    /* Certificate type is a single byte bitstring */
    if ((ret = mbedtls_asn1_get_tag(p, end, &bs->len, MBEDTLS_ASN1_BIT_STRING)) != 0) {
        return ret;
    }

    /* Check length, subtract one for actual bit string length */
    if (bs->len < 1) {
        return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
    }
    bs->len -= 1;

    /* Get number of unused bits, ensure unused bits <= 7 */
    bs->unused_bits = **p;
    if (bs->unused_bits > 7) {
        return MBEDTLS_ERR_ASN1_INVALID_LENGTH;
    }
    (*p)++;

    /* Get actual bitstring */
    bs->p = *p;
    *p += bs->len;

    if (*p != end) {
        return MBEDTLS_ERR_ASN1_LENGTH_MISMATCH;
    }

    return 0;
}

/*
 * Traverse an ASN.1 "SEQUENCE OF <tag>"
 * and call a callback for each entry found.
 */
int mbedtls_asn1_traverse_sequence_of(
    unsigned char **p,
    const unsigned char *end,
    unsigned char tag_must_mask, unsigned char tag_must_val,
    unsigned char tag_may_mask, unsigned char tag_may_val,
    int (*cb)(void *ctx, int tag,
              unsigned char *start, size_t len),
    void *ctx)
{
    int ret;
    size_t len;

    /* Get main sequence tag */
    if ((ret = mbedtls_asn1_get_tag(p, end, &len,
                                    MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
        return ret;
    }

    if (*p + len != end) {
        return MBEDTLS_ERR_ASN1_LENGTH_MISMATCH;
    }

    while (*p < end) {
        unsigned char const tag = *(*p)++;

        if ((tag & tag_must_mask) != tag_must_val) {
            return MBEDTLS_ERR_ASN1_UNEXPECTED_TAG;
        }

        if ((ret = mbedtls_asn1_get_len(p, end, &len)) != 0) {
            return ret;
        }

        if ((tag & tag_may_mask) == tag_may_val) {
            if (cb != NULL) {
                ret = cb(ctx, tag, *p, len);
                if (ret != 0) {
                    return ret;
                }
            }
        }

        *p += len;
    }

    return 0;
}

/*
 * Get a bit string without unused bits
 */
int mbedtls_asn1_get_bitstring_null(unsigned char **p, const unsigned char *end,
                                    size_t *len)
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;

    if ((ret = mbedtls_asn1_get_tag(p, end, len, MBEDTLS_ASN1_BIT_STRING)) != 0) {
        return ret;
    }

    if (*len == 0) {
        return MBEDTLS_ERR_ASN1_INVALID_DATA;
    }
    --(*len);

    if (**p != 0) {
        return MBEDTLS_ERR_ASN1_INVALID_DATA;
    }
    ++(*p);

    return 0;
}

void mbedtls_asn1_sequence_free(mbedtls_asn1_sequence *seq)
{
    while (seq != NULL) {
        mbedtls_asn1_sequence *next = seq->next;
        mbedtls_free(seq);
        seq = next;
    }
}

typedef struct {
    int tag;
    mbedtls_asn1_sequence *cur;
} asn1_get_sequence_of_cb_ctx_t;

static int asn1_get_sequence_of_cb(void *ctx,
                                   int tag,
                                   unsigned char *start,
                                   size_t len)
{
    asn1_get_sequence_of_cb_ctx_t *cb_ctx =
        (asn1_get_sequence_of_cb_ctx_t *) ctx;
    mbedtls_asn1_sequence *cur =
        cb_ctx->cur;

    if (cur->buf.p != NULL) {
        cur->next =
            mbedtls_calloc(1, sizeof(mbedtls_asn1_sequence));

        if (cur->next == NULL) {
            return MBEDTLS_ERR_ASN1_ALLOC_FAILED;
        }

        cur = cur->next;
    }

    cur->buf.p = start;
    cur->buf.len = len;
    cur->buf.tag = tag;

    cb_ctx->cur = cur;
    return 0;
}

/*
 *  Parses and splits an ASN.1 "SEQUENCE OF <tag>"
 */
int mbedtls_asn1_get_sequence_of(unsigned char **p,
                                 const unsigned char *end,
                                 mbedtls_asn1_sequence *cur,
                                 int tag)
{
    asn1_get_sequence_of_cb_ctx_t cb_ctx = { tag, cur };
    memset(cur, 0, sizeof(mbedtls_asn1_sequence));
    return mbedtls_asn1_traverse_sequence_of(
        p, end, 0xFF, tag, 0, 0,
        asn1_get_sequence_of_cb, &cb_ctx);
}

int mbedtls_asn1_get_alg(unsigned char **p,
                         const unsigned char *end,
                         mbedtls_asn1_buf *alg, mbedtls_asn1_buf *params)
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    size_t len;

    if ((ret = mbedtls_asn1_get_tag(p, end, &len,
                                    MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
        return ret;
    }

    if ((end - *p) < 1) {
        return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
    }

    alg->tag = **p;
    end = *p + len;

    if ((ret = mbedtls_asn1_get_tag(p, end, &alg->len, MBEDTLS_ASN1_OID)) != 0) {
        return ret;
    }

    alg->p = *p;
    *p += alg->len;

    if (*p == end) {
        mbedtls_platform_zeroize(params, sizeof(mbedtls_asn1_buf));
        return 0;
    }

    params->tag = **p;
    (*p)++;

    if ((ret = mbedtls_asn1_get_len(p, end, &params->len)) != 0) {
        return ret;
    }

    params->p = *p;
    *p += params->len;

    if (*p != end) {
        return MBEDTLS_ERR_ASN1_LENGTH_MISMATCH;
    }

    return 0;
}

int mbedtls_asn1_get_alg_null(unsigned char **p,
                              const unsigned char *end,
                              mbedtls_asn1_buf *alg)
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    mbedtls_asn1_buf params;

    memset(&params, 0, sizeof(mbedtls_asn1_buf));

    if ((ret = mbedtls_asn1_get_alg(p, end, alg, &params)) != 0) {
        return ret;
    }

    if ((params.tag != MBEDTLS_ASN1_NULL && params.tag != 0) || params.len != 0) {
        return MBEDTLS_ERR_ASN1_INVALID_DATA;
    }

    return 0;
}

#if !defined(MBEDTLS_DEPRECATED_REMOVED)
void mbedtls_asn1_free_named_data(mbedtls_asn1_named_data *cur)
{
    if (cur == NULL) {
        return;
    }

    mbedtls_free(cur->oid.p);
    mbedtls_free(cur->val.p);

    mbedtls_platform_zeroize(cur, sizeof(mbedtls_asn1_named_data));
}
#endif /* MBEDTLS_DEPRECATED_REMOVED */

void mbedtls_asn1_free_named_data_list(mbedtls_asn1_named_data **head)
{
    mbedtls_asn1_named_data *cur;

    while ((cur = *head) != NULL) {
        *head = cur->next;
        mbedtls_free(cur->oid.p);
        mbedtls_free(cur->val.p);
        mbedtls_free(cur);
    }
}

void mbedtls_asn1_free_named_data_list_shallow(mbedtls_asn1_named_data *name)
{
    for (mbedtls_asn1_named_data *next; name != NULL; name = next) {
        next = name->next;
        mbedtls_free(name);
    }
}

const mbedtls_asn1_named_data *mbedtls_asn1_find_named_data(const mbedtls_asn1_named_data *list,
                                                            const char *oid, size_t len)
{
    while (list != NULL) {
        if (list->oid.len == len &&
            memcmp(list->oid.p, oid, len) == 0) {
            break;
        }

        list = list->next;
    }

    return list;
}

#endif /* MBEDTLS_ASN1_PARSE_C */

Coverage Report

Created: 2024-08-17 06:45

Line	Count	Source (jump to first uncovered line)
1		/*
2		* Generic ASN.1 parsing
3		*
4		* Copyright The Mbed TLS Contributors
5		* SPDX-License-Identifier: Apache-2.0
6		*
7		* Licensed under the Apache License, Version 2.0 (the "License"); you may
8		* not use this file except in compliance with the License.
9		* You may obtain a copy of the License at
10		*
11		* http://www.apache.org/licenses/LICENSE-2.0
12		*
13		* Unless required by applicable law or agreed to in writing, software
14		* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
15		* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16		* See the License for the specific language governing permissions and
17		* limitations under the License.
18		*/
19
20		#include "common.h"
21
22		#if defined(MBEDTLS_ASN1_PARSE_C)
23
24		#include "mbedtls/asn1.h"
25		#include "mbedtls/platform_util.h"
26		#include "mbedtls/error.h"
27
28		#include <string.h>
29
30		#if defined(MBEDTLS_BIGNUM_C)
31		#include "mbedtls/bignum.h"
32		#endif
33
34		#include "mbedtls/platform.h"
35
36		/*
37		* ASN.1 DER decoding routines
38		*/
39		int mbedtls_asn1_get_len(unsigned char **p,
40		const unsigned char *end,
41		size_t *len)
42	167k	{
43	167k	if ((end - *p) < 1) {
44	12	return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
45	12	}
46
47	167k	if ((**p & 0x80) == 0) {
48	146k	len = (*p)++;
49	146k	} else {
50	20.5k	switch (**p & 0x7F) {
51	3.15k	case 1:
52	3.15k	if ((end - *p) < 2) {
53	4	return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
54	4	}
55
56	3.15k	len = (p)[1];
57	3.15k	(*p) += 2;
58	3.15k	break;
59
60	17.2k	case 2:
61	17.2k	if ((end - *p) < 3) {
62	9	return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
63	9	}
64
65	17.2k	len = ((size_t) (p)[1] << 8) \| (*p)[2];
66	17.2k	(*p) += 3;
67	17.2k	break;
68
69	33	case 3:
70	33	if ((end - *p) < 4) {
71	9	return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
72	9	}
73
74	24	len = ((size_t) (p)[1] << 16) \|
75	24	((size_t) (p)[2] << 8) \| (p)[3];
76	24	(*p) += 4;
77	24	break;
78
79	28	case 4:
80	28	if ((end - *p) < 5) {
81	10	return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
82	10	}
83
84	18	len = ((size_t) (p)[1] << 24) \| ((size_t) (*p)[2] << 16) \|
85	18	((size_t) (p)[3] << 8) \| (p)[4];
86	18	(*p) += 5;
87	18	break;
88
89	68	default:
90	68	return MBEDTLS_ERR_ASN1_INVALID_LENGTH;
91	20.5k	}
92	20.5k	}
93
94	167k	if (len > (size_t) (end - p)) {
95	119	return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
96	119	}
97
98	166k	return 0;
99	167k	}
100
101		int mbedtls_asn1_get_tag(unsigned char **p,
102		const unsigned char *end,
103		size_t *len, int tag)
104	145k	{
105	145k	if ((end - *p) < 1) {
106	12	return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
107	12	}
108
109	145k	if (**p != tag) {
110	11.9k	return MBEDTLS_ERR_ASN1_UNEXPECTED_TAG;
111	11.9k	}
112
113	133k	(*p)++;
114
115	133k	return mbedtls_asn1_get_len(p, end, len);
116	145k	}
117
118		int mbedtls_asn1_get_bool(unsigned char **p,
119		const unsigned char *end,
120		int *val)
121	8.56k	{
122	8.56k	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
123	8.56k	size_t len;
124
125	8.56k	if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_BOOLEAN)) != 0) {
126	7.01k	return ret;
127	7.01k	}
128
129	1.54k	if (len != 1) {
130	4	return MBEDTLS_ERR_ASN1_INVALID_LENGTH;
131	4	}
132
133	1.54k	val = (*p != 0) ? 1 : 0;
134	1.54k	(*p)++;
135
136	1.54k	return 0;
137	1.54k	}
138
139		static int asn1_get_tagged_int(unsigned char **p,
140		const unsigned char *end,
141		int tag, int *val)
142	3.28k	{
143	3.28k	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
144	3.28k	size_t len;
145
146	3.28k	if ((ret = mbedtls_asn1_get_tag(p, end, &len, tag)) != 0) {
147	29	return ret;
148	29	}
149
150		/*
151		* len==0 is malformed (0 must be represented as 020100 for INTEGER,
152		* or 0A0100 for ENUMERATED tags
153		*/
154	3.25k	if (len == 0) {
155	2	return MBEDTLS_ERR_ASN1_INVALID_LENGTH;
156	2	}
157		/* This is a cryptography library. Reject negative integers. */
158	3.25k	if ((**p & 0x80) != 0) {
159	4	return MBEDTLS_ERR_ASN1_INVALID_LENGTH;
160	4	}
161
162		/* Skip leading zeros. */
163	3.26k	while (len > 0 && **p == 0) {
164	11	++(*p);
165	11	--len;
166	11	}
167
168		/* Reject integers that don't fit in an int. This code assumes that
169		* the int type has no padding bit. */
170	3.24k	if (len > sizeof(int)) {
171	4	return MBEDTLS_ERR_ASN1_INVALID_LENGTH;
172	4	}
173	3.24k	if (len == sizeof(int) && (**p & 0x80) != 0) {
174	0	return MBEDTLS_ERR_ASN1_INVALID_LENGTH;
175	0	}
176
177	3.24k	*val = 0;
178	6.48k	while (len-- > 0) {
179	3.24k	val = (val << 8) \| **p;
180	3.24k	(*p)++;
181	3.24k	}
182
183	3.24k	return 0;
184	3.24k	}
185
186		int mbedtls_asn1_get_int(unsigned char **p,
187		const unsigned char *end,
188		int *val)
189	3.28k	{
190	3.28k	return asn1_get_tagged_int(p, end, MBEDTLS_ASN1_INTEGER, val);
191	3.28k	}
192
193		int mbedtls_asn1_get_enum(unsigned char **p,
194		const unsigned char *end,
195		int *val)
196	0	{
197	0	return asn1_get_tagged_int(p, end, MBEDTLS_ASN1_ENUMERATED, val);
198	0	}
199
200		#if defined(MBEDTLS_BIGNUM_C)
201		int mbedtls_asn1_get_mpi(unsigned char **p,
202		const unsigned char *end,
203		mbedtls_mpi *X)
204	0	{
205	0	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
206	0	size_t len;
207
208	0	if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_INTEGER)) != 0) {
209	0	return ret;
210	0	}
211
212	0	ret = mbedtls_mpi_read_binary(X, *p, len);
213
214	0	*p += len;
215
216	0	return ret;
217	0	}
218		#endif /* MBEDTLS_BIGNUM_C */
219
220		int mbedtls_asn1_get_bitstring(unsigned char *p, const unsigned char end,
221		mbedtls_asn1_bitstring *bs)
222	8	{
223	8	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
224
225		/* Certificate type is a single byte bitstring */
226	8	if ((ret = mbedtls_asn1_get_tag(p, end, &bs->len, MBEDTLS_ASN1_BIT_STRING)) != 0) {
227	8	return ret;
228	8	}
229
230		/* Check length, subtract one for actual bit string length */
231	0	if (bs->len < 1) {
232	0	return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
233	0	}
234	0	bs->len -= 1;
235
236		/* Get number of unused bits, ensure unused bits <= 7 */
237	0	bs->unused_bits = **p;
238	0	if (bs->unused_bits > 7) {
239	0	return MBEDTLS_ERR_ASN1_INVALID_LENGTH;
240	0	}
241	0	(*p)++;
242
243		/* Get actual bitstring */
244	0	bs->p = *p;
245	0	*p += bs->len;
246
247	0	if (*p != end) {
248	0	return MBEDTLS_ERR_ASN1_LENGTH_MISMATCH;
249	0	}
250
251	0	return 0;
252	0	}
253
254		/*
255		* Traverse an ASN.1 "SEQUENCE OF <tag>"
256		* and call a callback for each entry found.
257		*/
258		int mbedtls_asn1_traverse_sequence_of(
259		unsigned char **p,
260		const unsigned char *end,
261		unsigned char tag_must_mask, unsigned char tag_must_val,
262		unsigned char tag_may_mask, unsigned char tag_may_val,
263		int (cb)(void ctx, int tag,
264		unsigned char *start, size_t len),
265		void *ctx)
266	8	{
267	8	int ret;
268	8	size_t len;
269
270		/* Get main sequence tag */
271	8	if ((ret = mbedtls_asn1_get_tag(p, end, &len,
272	8	MBEDTLS_ASN1_CONSTRUCTED \| MBEDTLS_ASN1_SEQUENCE)) != 0) {
273	4	return ret;
274	4	}
275
276	4	if (*p + len != end) {
277	0	return MBEDTLS_ERR_ASN1_LENGTH_MISMATCH;
278	0	}
279
280	4	while (*p < end) {
281	3	unsigned char const tag = (p)++;
282
283	3	if ((tag & tag_must_mask) != tag_must_val) {
284	3	return MBEDTLS_ERR_ASN1_UNEXPECTED_TAG;
285	3	}
286
287	0	if ((ret = mbedtls_asn1_get_len(p, end, &len)) != 0) {
288	0	return ret;
289	0	}
290
291	0	if ((tag & tag_may_mask) == tag_may_val) {
292	0	if (cb != NULL) {
293	0	ret = cb(ctx, tag, *p, len);
294	0	if (ret != 0) {
295	0	return ret;
296	0	}
297	0	}
298	0	}
299
300	0	*p += len;
301	0	}
302
303	1	return 0;
304	4	}
305
306		/*
307		* Get a bit string without unused bits
308		*/
309		int mbedtls_asn1_get_bitstring_null(unsigned char *p, const unsigned char end,
310		size_t *len)
311	4.95k	{
312	4.95k	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
313
314	4.95k	if ((ret = mbedtls_asn1_get_tag(p, end, len, MBEDTLS_ASN1_BIT_STRING)) != 0) {
315	28	return ret;
316	28	}
317
318	4.92k	if (*len == 0) {
319	2	return MBEDTLS_ERR_ASN1_INVALID_DATA;
320	2	}
321	4.92k	--(*len);
322
323	4.92k	if (**p != 0) {
324	7	return MBEDTLS_ERR_ASN1_INVALID_DATA;
325	7	}
326	4.91k	++(*p);
327
328	4.91k	return 0;
329	4.92k	}
330
331		void mbedtls_asn1_sequence_free(mbedtls_asn1_sequence *seq)
332	11.0k	{
333	11.0k	while (seq != NULL) {
334	0	mbedtls_asn1_sequence *next = seq->next;
335	0	mbedtls_free(seq);
336	0	seq = next;
337	0	}
338	11.0k	}
339
340		typedef struct {
341		int tag;
342		mbedtls_asn1_sequence *cur;
343		} asn1_get_sequence_of_cb_ctx_t;
344
345		static int asn1_get_sequence_of_cb(void *ctx,
346		int tag,
347		unsigned char *start,
348		size_t len)
349	0	{
350	0	asn1_get_sequence_of_cb_ctx_t *cb_ctx =
351	0	(asn1_get_sequence_of_cb_ctx_t *) ctx;
352	0	mbedtls_asn1_sequence *cur =
353	0	cb_ctx->cur;
354
355	0	if (cur->buf.p != NULL) {
356	0	cur->next =
357	0	mbedtls_calloc(1, sizeof(mbedtls_asn1_sequence));
358
359	0	if (cur->next == NULL) {
360	0	return MBEDTLS_ERR_ASN1_ALLOC_FAILED;
361	0	}
362
363	0	cur = cur->next;
364	0	}
365
366	0	cur->buf.p = start;
367	0	cur->buf.len = len;
368	0	cur->buf.tag = tag;
369
370	0	cb_ctx->cur = cur;
371	0	return 0;
372	0	}
373
374		/*
375		* Parses and splits an ASN.1 "SEQUENCE OF <tag>"
376		*/
377		int mbedtls_asn1_get_sequence_of(unsigned char **p,
378		const unsigned char *end,
379		mbedtls_asn1_sequence *cur,
380		int tag)
381	8	{
382	8	asn1_get_sequence_of_cb_ctx_t cb_ctx = { tag, cur };
383	8	memset(cur, 0, sizeof(mbedtls_asn1_sequence));
384	8	return mbedtls_asn1_traverse_sequence_of(
385	8	p, end, 0xFF, tag, 0, 0,
386	8	asn1_get_sequence_of_cb, &cb_ctx);
387	8	}
388
389		int mbedtls_asn1_get_alg(unsigned char **p,
390		const unsigned char *end,
391		mbedtls_asn1_buf alg, mbedtls_asn1_buf params)
392	8.28k	{
393	8.28k	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
394	8.28k	size_t len;
395
396	8.28k	if ((ret = mbedtls_asn1_get_tag(p, end, &len,
397	8.28k	MBEDTLS_ASN1_CONSTRUCTED \| MBEDTLS_ASN1_SEQUENCE)) != 0) {
398	43	return ret;
399	43	}
400
401	8.24k	if ((end - *p) < 1) {
402	1	return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
403	1	}
404
405	8.24k	alg->tag = **p;
406	8.24k	end = *p + len;
407
408	8.24k	if ((ret = mbedtls_asn1_get_tag(p, end, &alg->len, MBEDTLS_ASN1_OID)) != 0) {
409	38	return ret;
410	38	}
411
412	8.20k	alg->p = *p;
413	8.20k	*p += alg->len;
414
415	8.20k	if (*p == end) {
416	875	mbedtls_platform_zeroize(params, sizeof(mbedtls_asn1_buf));
417	875	return 0;
418	875	}
419
420	7.32k	params->tag = **p;
421	7.32k	(*p)++;
422
423	7.32k	if ((ret = mbedtls_asn1_get_len(p, end, &params->len)) != 0) {
424	28	return ret;
425	28	}
426
427	7.29k	params->p = *p;
428	7.29k	*p += params->len;
429
430	7.29k	if (*p != end) {
431	3	return MBEDTLS_ERR_ASN1_LENGTH_MISMATCH;
432	3	}
433
434	7.29k	return 0;
435	7.29k	}
436
437		int mbedtls_asn1_get_alg_null(unsigned char **p,
438		const unsigned char *end,
439		mbedtls_asn1_buf *alg)
440	0	{
441	0	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
442	0	mbedtls_asn1_buf params;
443
444	0	memset(&params, 0, sizeof(mbedtls_asn1_buf));
445
446	0	if ((ret = mbedtls_asn1_get_alg(p, end, alg, &params)) != 0) {
447	0	return ret;
448	0	}
449
450	0	if ((params.tag != MBEDTLS_ASN1_NULL && params.tag != 0) \|\| params.len != 0) {
451	0	return MBEDTLS_ERR_ASN1_INVALID_DATA;
452	0	}
453
454	0	return 0;
455	0	}
456
457		#if !defined(MBEDTLS_DEPRECATED_REMOVED)
458		void mbedtls_asn1_free_named_data(mbedtls_asn1_named_data *cur)
459	0	{
460	0	if (cur == NULL) {
461	0	return;
462	0	}
463
464	0	mbedtls_free(cur->oid.p);
465	0	mbedtls_free(cur->val.p);
466
467	0	mbedtls_platform_zeroize(cur, sizeof(mbedtls_asn1_named_data));
468	0	}
469		#endif /* MBEDTLS_DEPRECATED_REMOVED */
470
471		void mbedtls_asn1_free_named_data_list(mbedtls_asn1_named_data **head)
472	0	{
473	0	mbedtls_asn1_named_data *cur;
474
475	0	while ((cur = *head) != NULL) {
476	0	*head = cur->next;
477	0	mbedtls_free(cur->oid.p);
478	0	mbedtls_free(cur->val.p);
479	0	mbedtls_free(cur);
480	0	}
481	0	}
482
483		void mbedtls_asn1_free_named_data_list_shallow(mbedtls_asn1_named_data *name)
484	7.47k	{
485	18.8k	for (mbedtls_asn1_named_data *next; name != NULL; name = next) {
486	11.3k	next = name->next;
487	11.3k	mbedtls_free(name);
488	11.3k	}
489	7.47k	}
490
491		const mbedtls_asn1_named_data mbedtls_asn1_find_named_data(const mbedtls_asn1_named_data list,
492		const char *oid, size_t len)
493	0	{
494	0	while (list != NULL) {
495	0	if (list->oid.len == len &&
496	0	memcmp(list->oid.p, oid, len) == 0) {
497	0	break;
498	0	}
499
500	0	list = list->next;
501	0	}
502
503	0	return list;
504	0	}
505
506		#endif /* MBEDTLS_ASN1_PARSE_C */