/src/duckdb/third_party/mbedtls/library/asn1write.cpp

Source (jump to first uncovered line)
/*
 * ASN.1 buffer writing functionality
 *
 *  Copyright The Mbed TLS Contributors
 *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
 */

#include "common.h"

#if defined(MBEDTLS_ASN1_WRITE_C) || defined(MBEDTLS_X509_USE_C) || \
    defined(MBEDTLS_PSA_UTIL_HAVE_ECDSA)

#include "mbedtls/asn1write.h"
#include "mbedtls/error.h"

#include <string.h>

#include "mbedtls/platform.h"

#if defined(MBEDTLS_ASN1_PARSE_C)
#include "mbedtls/asn1.h"
#endif

int mbedtls_asn1_write_len(unsigned char **p, const unsigned char *start, size_t len)
{
#if SIZE_MAX > 0xFFFFFFFF
    if (len > 0xFFFFFFFF) {
        return MBEDTLS_ERR_ASN1_INVALID_LENGTH;
    }
#endif

    int required = 1;

    if (len >= 0x80) {
        for (size_t l = len; l != 0; l >>= 8) {
            required++;
        }
    }

    if (required > (*p - start)) {
        return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
    }

    do {
        *--(*p) = MBEDTLS_BYTE_0(len);
        len >>= 8;
    } while (len);

    if (required > 1) {
        *--(*p) = (unsigned char) (0x80 + required - 1);
    }

    return required;
}

int mbedtls_asn1_write_tag(unsigned char **p, const unsigned char *start, unsigned char tag)
{
    if (*p - start < 1) {
        return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
    }

    *--(*p) = tag;

    return 1;
}
#endif /* MBEDTLS_ASN1_WRITE_C || MBEDTLS_X509_USE_C || MBEDTLS_PSA_UTIL_HAVE_ECDSA */

#if defined(MBEDTLS_ASN1_WRITE_C)
static int mbedtls_asn1_write_len_and_tag(unsigned char **p,
                                          const unsigned char *start,
                                          size_t len,
                                          unsigned char tag)
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;

    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, tag));

    return (int) len;
}

int mbedtls_asn1_write_raw_buffer(unsigned char **p, const unsigned char *start,
                                  const unsigned char *buf, size_t size)
{
    size_t len = 0;

    if (*p < start || (size_t) (*p - start) < size) {
        return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
    }

    len = size;
    (*p) -= len;
    memcpy(*p, buf, len);

    return (int) len;
}

#if defined(MBEDTLS_BIGNUM_C)
int mbedtls_asn1_write_mpi(unsigned char **p, const unsigned char *start, const mbedtls_mpi *X)
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    size_t len = 0;

    // Write the MPI
    //
    len = mbedtls_mpi_size(X);

    /* DER represents 0 with a sign bit (0=nonnegative) and 7 value bits, not
     * as 0 digits. We need to end up with 020100, not with 0200. */
    if (len == 0) {
        len = 1;
    }

    if (*p < start || (size_t) (*p - start) < len) {
        return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
    }

    (*p) -= len;
    MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(X, *p, len));

    // DER format assumes 2s complement for numbers, so the leftmost bit
    // should be 0 for positive numbers and 1 for negative numbers.
    //
    if (X->s == 1 && **p & 0x80) {
        if (*p - start < 1) {
            return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
        }

        *--(*p) = 0x00;
        len += 1;
    }

    ret = mbedtls_asn1_write_len_and_tag(p, start, len, MBEDTLS_ASN1_INTEGER);

cleanup:
    return ret;
}
#endif /* MBEDTLS_BIGNUM_C */

int mbedtls_asn1_write_null(unsigned char **p, const unsigned char *start)
{
    // Write NULL
    //
    return mbedtls_asn1_write_len_and_tag(p, start, 0, MBEDTLS_ASN1_NULL);
}

int mbedtls_asn1_write_oid(unsigned char **p, const unsigned char *start,
                           const char *oid, size_t oid_len)
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    size_t len = 0;

    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_raw_buffer(p, start,
                                                            (const unsigned char *) oid, oid_len));
    return mbedtls_asn1_write_len_and_tag(p, start, len, MBEDTLS_ASN1_OID);
}

int mbedtls_asn1_write_algorithm_identifier(unsigned char **p, const unsigned char *start,
                                            const char *oid, size_t oid_len,
                                            size_t par_len)
{
    return mbedtls_asn1_write_algorithm_identifier_ext(p, start, oid, oid_len, par_len, 1);
}

int mbedtls_asn1_write_algorithm_identifier_ext(unsigned char **p, const unsigned char *start,
                                                const char *oid, size_t oid_len,
                                                size_t par_len, int has_par)
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    size_t len = 0;

    if (has_par) {
        if (par_len == 0) {
            MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_null(p, start));
        } else {
            len += par_len;
        }
    }

    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_oid(p, start, oid, oid_len));

    return mbedtls_asn1_write_len_and_tag(p, start, len,
                                          MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE);
}

int mbedtls_asn1_write_bool(unsigned char **p, const unsigned char *start, int boolean)
{
    size_t len = 0;

    if (*p - start < 1) {
        return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
    }

    *--(*p) = (boolean) ? 255 : 0;
    len++;

    return mbedtls_asn1_write_len_and_tag(p, start, len, MBEDTLS_ASN1_BOOLEAN);
}

static int asn1_write_tagged_int(unsigned char **p, const unsigned char *start, int val, int tag)
{
    size_t len = 0;

    do {
        if (*p - start < 1) {
            return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
        }
        len += 1;
        *--(*p) = val & 0xff;
        val >>= 8;
    } while (val > 0);

    if (**p & 0x80) {
        if (*p - start < 1) {
            return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
        }
        *--(*p) = 0x00;
        len += 1;
    }

    return mbedtls_asn1_write_len_and_tag(p, start, len, tag);
}

int mbedtls_asn1_write_int(unsigned char **p, const unsigned char *start, int val)
{
    return asn1_write_tagged_int(p, start, val, MBEDTLS_ASN1_INTEGER);
}

int mbedtls_asn1_write_enum(unsigned char **p, const unsigned char *start, int val)
{
    return asn1_write_tagged_int(p, start, val, MBEDTLS_ASN1_ENUMERATED);
}

int mbedtls_asn1_write_tagged_string(unsigned char **p, const unsigned char *start, int tag,
                                     const char *text, size_t text_len)
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    size_t len = 0;

    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_raw_buffer(p, start,
                                                            (const unsigned char *) text,
                                                            text_len));

    return mbedtls_asn1_write_len_and_tag(p, start, len, tag);
}

int mbedtls_asn1_write_utf8_string(unsigned char **p, const unsigned char *start,
                                   const char *text, size_t text_len)
{
    return mbedtls_asn1_write_tagged_string(p, start, MBEDTLS_ASN1_UTF8_STRING, text, text_len);
}

int mbedtls_asn1_write_printable_string(unsigned char **p, const unsigned char *start,
                                        const char *text, size_t text_len)
{
    return mbedtls_asn1_write_tagged_string(p, start, MBEDTLS_ASN1_PRINTABLE_STRING, text,
                                            text_len);
}

int mbedtls_asn1_write_ia5_string(unsigned char **p, const unsigned char *start,
                                  const char *text, size_t text_len)
{
    return mbedtls_asn1_write_tagged_string(p, start, MBEDTLS_ASN1_IA5_STRING, text, text_len);
}

int mbedtls_asn1_write_named_bitstring(unsigned char **p,
                                       const unsigned char *start,
                                       const unsigned char *buf,
                                       size_t bits)
{
    size_t unused_bits, byte_len;
    const unsigned char *cur_byte;
    unsigned char cur_byte_shifted;
    unsigned char bit;

    byte_len = (bits + 7) / 8;
    unused_bits = (byte_len * 8) - bits;

    /*
     * Named bitstrings require that trailing 0s are excluded in the encoding
     * of the bitstring. Trailing 0s are considered part of the 'unused' bits
     * when encoding this value in the first content octet
     */
    if (bits != 0) {
        cur_byte = buf + byte_len - 1;
        cur_byte_shifted = *cur_byte >> unused_bits;

        for (;;) {
            bit = cur_byte_shifted & 0x1;
            cur_byte_shifted >>= 1;

            if (bit != 0) {
                break;
            }

            bits--;
            if (bits == 0) {
                break;
            }

            if (bits % 8 == 0) {
                cur_byte_shifted = *--cur_byte;
            }
        }
    }

    return mbedtls_asn1_write_bitstring(p, start, buf, bits);
}

int mbedtls_asn1_write_bitstring(unsigned char **p, const unsigned char *start,
                                 const unsigned char *buf, size_t bits)
{
    size_t len = 0;
    size_t unused_bits, byte_len;

    byte_len = (bits + 7) / 8;
    unused_bits = (byte_len * 8) - bits;

    if (*p < start || (size_t) (*p - start) < byte_len + 1) {
        return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
    }

    len = byte_len + 1;

    /* Write the bitstring. Ensure the unused bits are zeroed */
    if (byte_len > 0) {
        byte_len--;
        *--(*p) = buf[byte_len] & ~((0x1 << unused_bits) - 1);
        (*p) -= byte_len;
        memcpy(*p, buf, byte_len);
    }

    /* Write unused bits */
    *--(*p) = (unsigned char) unused_bits;

    return mbedtls_asn1_write_len_and_tag(p, start, len, MBEDTLS_ASN1_BIT_STRING);
}

int mbedtls_asn1_write_octet_string(unsigned char **p, const unsigned char *start,
                                    const unsigned char *buf, size_t size)
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    size_t len = 0;

    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_raw_buffer(p, start, buf, size));

    return mbedtls_asn1_write_len_and_tag(p, start, len, MBEDTLS_ASN1_OCTET_STRING);
}


#if !defined(MBEDTLS_ASN1_PARSE_C)
/* This is a copy of the ASN.1 parsing function mbedtls_asn1_find_named_data(),
 * which is replicated to avoid a dependency ASN1_WRITE_C on ASN1_PARSE_C. */
static mbedtls_asn1_named_data *asn1_find_named_data(
    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;
}
#else
#define asn1_find_named_data(list, oid, len) \
    ((mbedtls_asn1_named_data *) mbedtls_asn1_find_named_data(list, oid, len))
#endif

mbedtls_asn1_named_data *mbedtls_asn1_store_named_data(
    mbedtls_asn1_named_data **head,
    const char *oid, size_t oid_len,
    const unsigned char *val,
    size_t val_len)
{
    mbedtls_asn1_named_data *cur;

    if ((cur = asn1_find_named_data(*head, oid, oid_len)) == NULL) {
        // Add new entry if not present yet based on OID
        //
        cur = (mbedtls_asn1_named_data *) mbedtls_calloc(1,
                                                         sizeof(mbedtls_asn1_named_data));
        if (cur == NULL) {
            return NULL;
        }

        cur->oid.len = oid_len;
        cur->oid.p = (unsigned char *) mbedtls_calloc(1, oid_len);
        if (cur->oid.p == NULL) {
            mbedtls_free(cur);
            return NULL;
        }

        memcpy(cur->oid.p, oid, oid_len);

        cur->val.len = val_len;
        if (val_len != 0) {
            cur->val.p = (unsigned char *) mbedtls_calloc(1, val_len);
            if (cur->val.p == NULL) {
                mbedtls_free(cur->oid.p);
                mbedtls_free(cur);
                return NULL;
            }
        }

        cur->next = *head;
        *head = cur;
    } else if (val_len == 0) {
        mbedtls_free(cur->val.p);
        cur->val.p = NULL;
    } else if (cur->val.len != val_len) {
        /*
         * Enlarge existing value buffer if needed
         * Preserve old data until the allocation succeeded, to leave list in
         * a consistent state in case allocation fails.
         */
        void *p = mbedtls_calloc(1, val_len);
        if (p == NULL) {
            return NULL;
        }

        mbedtls_free(cur->val.p);
        cur->val.p = (unsigned char *)p;
        cur->val.len = val_len;
    }

    if (val != NULL && val_len != 0) {
        memcpy(cur->val.p, val, val_len);
    }

    return cur;
}
#endif /* MBEDTLS_ASN1_WRITE_C */

Coverage Report

Created: 2025-06-12 07:25

Line	Count	Source (jump to first uncovered line)
1		/*
2		* ASN.1 buffer writing functionality
3		*
4		* Copyright The Mbed TLS Contributors
5		* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
6		*/
7
8		#include "common.h"
9
10		#if defined(MBEDTLS_ASN1_WRITE_C) \|\| defined(MBEDTLS_X509_USE_C) \|\| \
11		defined(MBEDTLS_PSA_UTIL_HAVE_ECDSA)
12
13		#include "mbedtls/asn1write.h"
14		#include "mbedtls/error.h"
15
16		#include <string.h>
17
18		#include "mbedtls/platform.h"
19
20		#if defined(MBEDTLS_ASN1_PARSE_C)
21		#include "mbedtls/asn1.h"
22		#endif
23
24		int mbedtls_asn1_write_len(unsigned char *p, const unsigned char start, size_t len)
25	0	{
26	0	#if SIZE_MAX > 0xFFFFFFFF
27	0	if (len > 0xFFFFFFFF) {
28	0	return MBEDTLS_ERR_ASN1_INVALID_LENGTH;
29	0	}
30	0	#endif
31
32	0	int required = 1;
33
34	0	if (len >= 0x80) {
35	0	for (size_t l = len; l != 0; l >>= 8) {
36	0	required++;
37	0	}
38	0	}
39
40	0	if (required > (*p - start)) {
41	0	return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
42	0	}
43
44	0	do {
45	0	--(p) = MBEDTLS_BYTE_0(len);
46	0	len >>= 8;
47	0	} while (len);
48
49	0	if (required > 1) {
50	0	--(p) = (unsigned char) (0x80 + required - 1);
51	0	}
52
53	0	return required;
54	0	}
55
56		int mbedtls_asn1_write_tag(unsigned char *p, const unsigned char start, unsigned char tag)
57	0	{
58	0	if (*p - start < 1) {
59	0	return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
60	0	}
61
62	0	--(p) = tag;
63
64	0	return 1;
65	0	}
66		#endif /* MBEDTLS_ASN1_WRITE_C \|\| MBEDTLS_X509_USE_C \|\| MBEDTLS_PSA_UTIL_HAVE_ECDSA */
67
68		#if defined(MBEDTLS_ASN1_WRITE_C)
69		static int mbedtls_asn1_write_len_and_tag(unsigned char **p,
70		const unsigned char *start,
71		size_t len,
72		unsigned char tag)
73	0	{
74	0	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
75
76	0	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
77	0	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, tag));
78
79	0	return (int) len;
80	0	}
81
82		int mbedtls_asn1_write_raw_buffer(unsigned char *p, const unsigned char start,
83		const unsigned char *buf, size_t size)
84	0	{
85	0	size_t len = 0;
86
87	0	if (p < start \|\| (size_t) (p - start) < size) {
88	0	return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
89	0	}
90
91	0	len = size;
92	0	(*p) -= len;
93	0	memcpy(*p, buf, len);
94
95	0	return (int) len;
96	0	}
97
98		#if defined(MBEDTLS_BIGNUM_C)
99		int mbedtls_asn1_write_mpi(unsigned char *p, const unsigned char start, const mbedtls_mpi *X)
100	0	{
101	0	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
102	0	size_t len = 0;
103
104		// Write the MPI
105		//
106	0	len = mbedtls_mpi_size(X);
107
108		/* DER represents 0 with a sign bit (0=nonnegative) and 7 value bits, not
109		* as 0 digits. We need to end up with 020100, not with 0200. */
110	0	if (len == 0) {
111	0	len = 1;
112	0	}
113
114	0	if (p < start \|\| (size_t) (p - start) < len) {
115	0	return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
116	0	}
117
118	0	(*p) -= len;
119	0	MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(X, *p, len));
120
121		// DER format assumes 2s complement for numbers, so the leftmost bit
122		// should be 0 for positive numbers and 1 for negative numbers.
123		//
124	0	if (X->s == 1 && **p & 0x80) {
125	0	if (*p - start < 1) {
126	0	return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
127	0	}
128
129	0	--(p) = 0x00;
130	0	len += 1;
131	0	}
132
133	0	ret = mbedtls_asn1_write_len_and_tag(p, start, len, MBEDTLS_ASN1_INTEGER);
134
135	0	cleanup:
136	0	return ret;
137	0	}
138		#endif /* MBEDTLS_BIGNUM_C */
139
140		int mbedtls_asn1_write_null(unsigned char *p, const unsigned char start)
141	0	{
142		// Write NULL
143		//
144	0	return mbedtls_asn1_write_len_and_tag(p, start, 0, MBEDTLS_ASN1_NULL);
145	0	}
146
147		int mbedtls_asn1_write_oid(unsigned char *p, const unsigned char start,
148		const char *oid, size_t oid_len)
149	0	{
150	0	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
151	0	size_t len = 0;
152
153	0	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_raw_buffer(p, start,
154	0	(const unsigned char *) oid, oid_len));
155	0	return mbedtls_asn1_write_len_and_tag(p, start, len, MBEDTLS_ASN1_OID);
156	0	}
157
158		int mbedtls_asn1_write_algorithm_identifier(unsigned char *p, const unsigned char start,
159		const char *oid, size_t oid_len,
160		size_t par_len)
161	0	{
162	0	return mbedtls_asn1_write_algorithm_identifier_ext(p, start, oid, oid_len, par_len, 1);
163	0	}
164
165		int mbedtls_asn1_write_algorithm_identifier_ext(unsigned char *p, const unsigned char start,
166		const char *oid, size_t oid_len,
167		size_t par_len, int has_par)
168	0	{
169	0	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
170	0	size_t len = 0;
171
172	0	if (has_par) {
173	0	if (par_len == 0) {
174	0	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_null(p, start));
175	0	} else {
176	0	len += par_len;
177	0	}
178	0	}
179
180	0	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_oid(p, start, oid, oid_len));
181
182	0	return mbedtls_asn1_write_len_and_tag(p, start, len,
183	0	MBEDTLS_ASN1_CONSTRUCTED \| MBEDTLS_ASN1_SEQUENCE);
184	0	}
185
186		int mbedtls_asn1_write_bool(unsigned char *p, const unsigned char start, int boolean)
187	0	{
188	0	size_t len = 0;
189
190	0	if (*p - start < 1) {
191	0	return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
192	0	}
193
194	0	--(p) = (boolean) ? 255 : 0;
195	0	len++;
196
197	0	return mbedtls_asn1_write_len_and_tag(p, start, len, MBEDTLS_ASN1_BOOLEAN);
198	0	}
199
200		static int asn1_write_tagged_int(unsigned char *p, const unsigned char start, int val, int tag)
201	0	{
202	0	size_t len = 0;
203
204	0	do {
205	0	if (*p - start < 1) {
206	0	return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
207	0	}
208	0	len += 1;
209	0	--(p) = val & 0xff;
210	0	val >>= 8;
211	0	} while (val > 0);
212
213	0	if (**p & 0x80) {
214	0	if (*p - start < 1) {
215	0	return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
216	0	}
217	0	--(p) = 0x00;
218	0	len += 1;
219	0	}
220
221	0	return mbedtls_asn1_write_len_and_tag(p, start, len, tag);
222	0	}
223
224		int mbedtls_asn1_write_int(unsigned char *p, const unsigned char start, int val)
225	0	{
226	0	return asn1_write_tagged_int(p, start, val, MBEDTLS_ASN1_INTEGER);
227	0	}
228
229		int mbedtls_asn1_write_enum(unsigned char *p, const unsigned char start, int val)
230	0	{
231	0	return asn1_write_tagged_int(p, start, val, MBEDTLS_ASN1_ENUMERATED);
232	0	}
233
234		int mbedtls_asn1_write_tagged_string(unsigned char *p, const unsigned char start, int tag,
235		const char *text, size_t text_len)
236	0	{
237	0	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
238	0	size_t len = 0;
239
240	0	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_raw_buffer(p, start,
241	0	(const unsigned char *) text,
242	0	text_len));
243
244	0	return mbedtls_asn1_write_len_and_tag(p, start, len, tag);
245	0	}
246
247		int mbedtls_asn1_write_utf8_string(unsigned char *p, const unsigned char start,
248		const char *text, size_t text_len)
249	0	{
250	0	return mbedtls_asn1_write_tagged_string(p, start, MBEDTLS_ASN1_UTF8_STRING, text, text_len);
251	0	}
252
253		int mbedtls_asn1_write_printable_string(unsigned char *p, const unsigned char start,
254		const char *text, size_t text_len)
255	0	{
256	0	return mbedtls_asn1_write_tagged_string(p, start, MBEDTLS_ASN1_PRINTABLE_STRING, text,
257	0	text_len);
258	0	}
259
260		int mbedtls_asn1_write_ia5_string(unsigned char *p, const unsigned char start,
261		const char *text, size_t text_len)
262	0	{
263	0	return mbedtls_asn1_write_tagged_string(p, start, MBEDTLS_ASN1_IA5_STRING, text, text_len);
264	0	}
265
266		int mbedtls_asn1_write_named_bitstring(unsigned char **p,
267		const unsigned char *start,
268		const unsigned char *buf,
269		size_t bits)
270	0	{
271	0	size_t unused_bits, byte_len;
272	0	const unsigned char *cur_byte;
273	0	unsigned char cur_byte_shifted;
274	0	unsigned char bit;
275
276	0	byte_len = (bits + 7) / 8;
277	0	unused_bits = (byte_len * 8) - bits;
278
279		/*
280		* Named bitstrings require that trailing 0s are excluded in the encoding
281		* of the bitstring. Trailing 0s are considered part of the 'unused' bits
282		* when encoding this value in the first content octet
283		*/
284	0	if (bits != 0) {
285	0	cur_byte = buf + byte_len - 1;
286	0	cur_byte_shifted = *cur_byte >> unused_bits;
287
288	0	for (;;) {
289	0	bit = cur_byte_shifted & 0x1;
290	0	cur_byte_shifted >>= 1;
291
292	0	if (bit != 0) {
293	0	break;
294	0	}
295
296	0	bits--;
297	0	if (bits == 0) {
298	0	break;
299	0	}
300
301	0	if (bits % 8 == 0) {
302	0	cur_byte_shifted = *--cur_byte;
303	0	}
304	0	}
305	0	}
306
307	0	return mbedtls_asn1_write_bitstring(p, start, buf, bits);
308	0	}
309
310		int mbedtls_asn1_write_bitstring(unsigned char *p, const unsigned char start,
311		const unsigned char *buf, size_t bits)
312	0	{
313	0	size_t len = 0;
314	0	size_t unused_bits, byte_len;
315
316	0	byte_len = (bits + 7) / 8;
317	0	unused_bits = (byte_len * 8) - bits;
318
319	0	if (p < start \|\| (size_t) (p - start) < byte_len + 1) {
320	0	return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
321	0	}
322
323	0	len = byte_len + 1;
324
325		/* Write the bitstring. Ensure the unused bits are zeroed */
326	0	if (byte_len > 0) {
327	0	byte_len--;
328	0	--(p) = buf[byte_len] & ~((0x1 << unused_bits) - 1);
329	0	(*p) -= byte_len;
330	0	memcpy(*p, buf, byte_len);
331	0	}
332
333		/* Write unused bits */
334	0	--(p) = (unsigned char) unused_bits;
335
336	0	return mbedtls_asn1_write_len_and_tag(p, start, len, MBEDTLS_ASN1_BIT_STRING);
337	0	}
338
339		int mbedtls_asn1_write_octet_string(unsigned char *p, const unsigned char start,
340		const unsigned char *buf, size_t size)
341	0	{
342	0	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
343	0	size_t len = 0;
344
345	0	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_raw_buffer(p, start, buf, size));
346
347	0	return mbedtls_asn1_write_len_and_tag(p, start, len, MBEDTLS_ASN1_OCTET_STRING);
348	0	}
349
350
351		#if !defined(MBEDTLS_ASN1_PARSE_C)
352		/* This is a copy of the ASN.1 parsing function mbedtls_asn1_find_named_data(),
353		* which is replicated to avoid a dependency ASN1_WRITE_C on ASN1_PARSE_C. */
354		static mbedtls_asn1_named_data *asn1_find_named_data(
355		mbedtls_asn1_named_data *list,
356		const char *oid, size_t len)
357		{
358		while (list != NULL) {
359		if (list->oid.len == len &&
360		memcmp(list->oid.p, oid, len) == 0) {
361		break;
362		}
363
364		list = list->next;
365		}
366
367		return list;
368		}
369		#else
370		#define asn1_find_named_data(list, oid, len) \
371	0	((mbedtls_asn1_named_data *) mbedtls_asn1_find_named_data(list, oid, len))
372		#endif
373
374		mbedtls_asn1_named_data *mbedtls_asn1_store_named_data(
375		mbedtls_asn1_named_data **head,
376		const char *oid, size_t oid_len,
377		const unsigned char *val,
378		size_t val_len)
379	0	{
380	0	mbedtls_asn1_named_data *cur;
381
382	0	if ((cur = asn1_find_named_data(*head, oid, oid_len)) == NULL) {
383		// Add new entry if not present yet based on OID
384		//
385	0	cur = (mbedtls_asn1_named_data *) mbedtls_calloc(1,
386	0	sizeof(mbedtls_asn1_named_data));
387	0	if (cur == NULL) {
388	0	return NULL;
389	0	}
390
391	0	cur->oid.len = oid_len;
392	0	cur->oid.p = (unsigned char *) mbedtls_calloc(1, oid_len);
393	0	if (cur->oid.p == NULL) {
394	0	mbedtls_free(cur);
395	0	return NULL;
396	0	}
397
398	0	memcpy(cur->oid.p, oid, oid_len);
399
400	0	cur->val.len = val_len;
401	0	if (val_len != 0) {
402	0	cur->val.p = (unsigned char *) mbedtls_calloc(1, val_len);
403	0	if (cur->val.p == NULL) {
404	0	mbedtls_free(cur->oid.p);
405	0	mbedtls_free(cur);
406	0	return NULL;
407	0	}
408	0	}
409
410	0	cur->next = *head;
411	0	*head = cur;
412	0	} else if (val_len == 0) {
413	0	mbedtls_free(cur->val.p);
414	0	cur->val.p = NULL;
415	0	} else if (cur->val.len != val_len) {
416		/*
417		* Enlarge existing value buffer if needed
418		* Preserve old data until the allocation succeeded, to leave list in
419		* a consistent state in case allocation fails.
420		*/
421	0	void *p = mbedtls_calloc(1, val_len);
422	0	if (p == NULL) {
423	0	return NULL;
424	0	}
425
426	0	mbedtls_free(cur->val.p);
427	0	cur->val.p = (unsigned char *)p;
428	0	cur->val.len = val_len;
429	0	}
430
431	0	if (val != NULL && val_len != 0) {
432	0	memcpy(cur->val.p, val, val_len);
433	0	}
434
435	0	return cur;
436	0	}
437		#endif /* MBEDTLS_ASN1_WRITE_C */