/work/mbedtls-2.28.8/library/asn1write.c

Source
/*
 * 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)

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

#include <string.h>

#include "mbedtls/platform.h"

int mbedtls_asn1_write_len(unsigned char **p, unsigned char *start, size_t len)
{
    if (len < 0x80) {
        if (*p - start < 1) {
            return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
        }

        *--(*p) = (unsigned char) len;
        return 1;
    }

    if (len <= 0xFF) {
        if (*p - start < 2) {
            return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
        }

        *--(*p) = (unsigned char) len;
        *--(*p) = 0x81;
        return 2;
    }

    if (len <= 0xFFFF) {
        if (*p - start < 3) {
            return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
        }

        *--(*p) = MBEDTLS_BYTE_0(len);
        *--(*p) = MBEDTLS_BYTE_1(len);
        *--(*p) = 0x82;
        return 3;
    }

    if (len <= 0xFFFFFF) {
        if (*p - start < 4) {
            return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
        }

        *--(*p) = MBEDTLS_BYTE_0(len);
        *--(*p) = MBEDTLS_BYTE_1(len);
        *--(*p) = MBEDTLS_BYTE_2(len);
        *--(*p) = 0x83;
        return 4;
    }

    int len_is_valid = 1;
#if SIZE_MAX > 0xFFFFFFFF
    len_is_valid = (len <= 0xFFFFFFFF);
#endif
    if (len_is_valid) {
        if (*p - start < 5) {
            return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
        }

        *--(*p) = MBEDTLS_BYTE_0(len);
        *--(*p) = MBEDTLS_BYTE_1(len);
        *--(*p) = MBEDTLS_BYTE_2(len);
        *--(*p) = MBEDTLS_BYTE_3(len);
        *--(*p) = 0x84;
        return 5;
    }

    return MBEDTLS_ERR_ASN1_INVALID_LENGTH;
}

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

    *--(*p) = tag;

    return 1;
}

int mbedtls_asn1_write_raw_buffer(unsigned char **p, 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, 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;
    }

    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_INTEGER));

    ret = (int) len;

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

int mbedtls_asn1_write_null(unsigned char **p, unsigned char *start)
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    size_t len = 0;

    // Write NULL
    //
    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, 0));
    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_NULL));

    return (int) len;
}

int mbedtls_asn1_write_oid(unsigned char **p, 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));
    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_OID));

    return (int) len;
}

int mbedtls_asn1_write_algorithm_identifier(unsigned char **p, 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, 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));

    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start,
                                                     MBEDTLS_ASN1_CONSTRUCTED |
                                                     MBEDTLS_ASN1_SEQUENCE));

    return (int) len;
}

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

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

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

    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_BOOLEAN));

    return (int) len;
}

static int asn1_write_tagged_int(unsigned char **p, unsigned char *start, int val, int tag)
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    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;
    }

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

int mbedtls_asn1_write_enum(unsigned char **p, 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, 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));

    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_utf8_string(unsigned char **p, 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, 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, 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,
                                       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, unsigned char *start,
                                 const unsigned char *buf, size_t bits)
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    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;

    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_BIT_STRING));

    return (int) len;
}

int mbedtls_asn1_write_octet_string(unsigned char **p, 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));

    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_OCTET_STRING));

    return (int) len;
}


/* 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;
}

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 = 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 = 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 = 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: 2025-10-28 06:49

Line	Count	Source
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)
11
12		#include "mbedtls/asn1write.h"
13		#include "mbedtls/error.h"
14
15		#include <string.h>
16
17		#include "mbedtls/platform.h"
18
19		int mbedtls_asn1_write_len(unsigned char *p, unsigned char start, size_t len)
20	0	{
21	0	if (len < 0x80) {
22	0	if (*p - start < 1) {
23	0	return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
24	0	}
25
26	0	--(p) = (unsigned char) len;
27	0	return 1;
28	0	}
29
30	0	if (len <= 0xFF) {
31	0	if (*p - start < 2) {
32	0	return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
33	0	}
34
35	0	--(p) = (unsigned char) len;
36	0	--(p) = 0x81;
37	0	return 2;
38	0	}
39
40	0	if (len <= 0xFFFF) {
41	0	if (*p - start < 3) {
42	0	return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
43	0	}
44
45	0	--(p) = MBEDTLS_BYTE_0(len);
46	0	--(p) = MBEDTLS_BYTE_1(len);
47	0	--(p) = 0x82;
48	0	return 3;
49	0	}
50
51	0	if (len <= 0xFFFFFF) {
52	0	if (*p - start < 4) {
53	0	return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
54	0	}
55
56	0	--(p) = MBEDTLS_BYTE_0(len);
57	0	--(p) = MBEDTLS_BYTE_1(len);
58	0	--(p) = MBEDTLS_BYTE_2(len);
59	0	--(p) = 0x83;
60	0	return 4;
61	0	}
62
63	0	int len_is_valid = 1;
64	0	#if SIZE_MAX > 0xFFFFFFFF
65	0	len_is_valid = (len <= 0xFFFFFFFF);
66	0	#endif
67	0	if (len_is_valid) {
68	0	if (*p - start < 5) {
69	0	return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
70	0	}
71
72	0	--(p) = MBEDTLS_BYTE_0(len);
73	0	--(p) = MBEDTLS_BYTE_1(len);
74	0	--(p) = MBEDTLS_BYTE_2(len);
75	0	--(p) = MBEDTLS_BYTE_3(len);
76	0	--(p) = 0x84;
77	0	return 5;
78	0	}
79
80	0	return MBEDTLS_ERR_ASN1_INVALID_LENGTH;
81	0	}
82
83		int mbedtls_asn1_write_tag(unsigned char *p, unsigned char start, unsigned char tag)
84	0	{
85	0	if (*p - start < 1) {
86	0	return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
87	0	}
88
89	0	--(p) = tag;
90
91	0	return 1;
92	0	}
93
94		int mbedtls_asn1_write_raw_buffer(unsigned char *p, unsigned char start,
95		const unsigned char *buf, size_t size)
96	0	{
97	0	size_t len = 0;
98
99	0	if (p < start \|\| (size_t) (p - start) < size) {
100	0	return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
101	0	}
102
103	0	len = size;
104	0	(*p) -= len;
105	0	memcpy(*p, buf, len);
106
107	0	return (int) len;
108	0	}
109
110		#if defined(MBEDTLS_BIGNUM_C)
111		int mbedtls_asn1_write_mpi(unsigned char *p, unsigned char start, const mbedtls_mpi *X)
112	0	{
113	0	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
114	0	size_t len = 0;
115
116		// Write the MPI
117		//
118	0	len = mbedtls_mpi_size(X);
119
120		/* DER represents 0 with a sign bit (0=nonnegative) and 7 value bits, not
121		* as 0 digits. We need to end up with 020100, not with 0200. */
122	0	if (len == 0) {
123	0	len = 1;
124	0	}
125
126	0	if (p < start \|\| (size_t) (p - start) < len) {
127	0	return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
128	0	}
129
130	0	(*p) -= len;
131	0	MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(X, *p, len));
132
133		// DER format assumes 2s complement for numbers, so the leftmost bit
134		// should be 0 for positive numbers and 1 for negative numbers.
135		//
136	0	if (X->s == 1 && **p & 0x80) {
137	0	if (*p - start < 1) {
138	0	return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
139	0	}
140
141	0	--(p) = 0x00;
142	0	len += 1;
143	0	}
144
145	0	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
146	0	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_INTEGER));
147
148	0	ret = (int) len;
149
150	0	cleanup:
151	0	return ret;
152	0	}
153		#endif /* MBEDTLS_BIGNUM_C */
154
155		int mbedtls_asn1_write_null(unsigned char *p, unsigned char start)
156	0	{
157	0	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
158	0	size_t len = 0;
159
160		// Write NULL
161		//
162	0	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, 0));
163	0	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_NULL));
164
165	0	return (int) len;
166	0	}
167
168		int mbedtls_asn1_write_oid(unsigned char *p, unsigned char start,
169		const char *oid, size_t oid_len)
170	0	{
171	0	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
172	0	size_t len = 0;
173
174	0	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_raw_buffer(p, start,
175	0	(const unsigned char *) oid, oid_len));
176	0	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
177	0	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_OID));
178
179	0	return (int) len;
180	0	}
181
182		int mbedtls_asn1_write_algorithm_identifier(unsigned char *p, unsigned char start,
183		const char *oid, size_t oid_len,
184		size_t par_len)
185	0	{
186	0	return mbedtls_asn1_write_algorithm_identifier_ext(p, start, oid, oid_len, par_len, 1);
187	0	}
188
189		int mbedtls_asn1_write_algorithm_identifier_ext(unsigned char *p, unsigned char start,
190		const char *oid, size_t oid_len,
191		size_t par_len, int has_par)
192	0	{
193	0	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
194	0	size_t len = 0;
195
196	0	if (has_par) {
197	0	if (par_len == 0) {
198	0	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_null(p, start));
199	0	} else {
200	0	len += par_len;
201	0	}
202	0	}
203
204	0	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_oid(p, start, oid, oid_len));
205
206	0	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
207	0	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start,
208	0	MBEDTLS_ASN1_CONSTRUCTED \|
209	0	MBEDTLS_ASN1_SEQUENCE));
210
211	0	return (int) len;
212	0	}
213
214		int mbedtls_asn1_write_bool(unsigned char *p, unsigned char start, int boolean)
215	0	{
216	0	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
217	0	size_t len = 0;
218
219	0	if (*p - start < 1) {
220	0	return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
221	0	}
222
223	0	--(p) = (boolean) ? 255 : 0;
224	0	len++;
225
226	0	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
227	0	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_BOOLEAN));
228
229	0	return (int) len;
230	0	}
231
232		static int asn1_write_tagged_int(unsigned char *p, unsigned char start, int val, int tag)
233	0	{
234	0	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
235	0	size_t len = 0;
236
237	0	do {
238	0	if (*p - start < 1) {
239	0	return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
240	0	}
241	0	len += 1;
242	0	--(p) = val & 0xff;
243	0	val >>= 8;
244	0	} while (val > 0);
245
246	0	if (**p & 0x80) {
247	0	if (*p - start < 1) {
248	0	return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
249	0	}
250	0	--(p) = 0x00;
251	0	len += 1;
252	0	}
253
254	0	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
255	0	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, tag));
256
257	0	return (int) len;
258	0	}
259
260		int mbedtls_asn1_write_int(unsigned char *p, unsigned char start, int val)
261	0	{
262	0	return asn1_write_tagged_int(p, start, val, MBEDTLS_ASN1_INTEGER);
263	0	}
264
265		int mbedtls_asn1_write_enum(unsigned char *p, unsigned char start, int val)
266	0	{
267	0	return asn1_write_tagged_int(p, start, val, MBEDTLS_ASN1_ENUMERATED);
268	0	}
269
270		int mbedtls_asn1_write_tagged_string(unsigned char *p, unsigned char start, int tag,
271		const char *text, size_t text_len)
272	0	{
273	0	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
274	0	size_t len = 0;
275
276	0	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_raw_buffer(p, start,
277	0	(const unsigned char *) text,
278	0	text_len));
279
280	0	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
281	0	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, tag));
282
283	0	return (int) len;
284	0	}
285
286		int mbedtls_asn1_write_utf8_string(unsigned char *p, unsigned char start,
287		const char *text, size_t text_len)
288	0	{
289	0	return mbedtls_asn1_write_tagged_string(p, start, MBEDTLS_ASN1_UTF8_STRING, text, text_len);
290	0	}
291
292		int mbedtls_asn1_write_printable_string(unsigned char *p, unsigned char start,
293		const char *text, size_t text_len)
294	0	{
295	0	return mbedtls_asn1_write_tagged_string(p, start, MBEDTLS_ASN1_PRINTABLE_STRING, text,
296	0	text_len);
297	0	}
298
299		int mbedtls_asn1_write_ia5_string(unsigned char *p, unsigned char start,
300		const char *text, size_t text_len)
301	0	{
302	0	return mbedtls_asn1_write_tagged_string(p, start, MBEDTLS_ASN1_IA5_STRING, text, text_len);
303	0	}
304
305		int mbedtls_asn1_write_named_bitstring(unsigned char **p,
306		unsigned char *start,
307		const unsigned char *buf,
308		size_t bits)
309	0	{
310	0	size_t unused_bits, byte_len;
311	0	const unsigned char *cur_byte;
312	0	unsigned char cur_byte_shifted;
313	0	unsigned char bit;
314
315	0	byte_len = (bits + 7) / 8;
316	0	unused_bits = (byte_len * 8) - bits;
317
318		/*
319		* Named bitstrings require that trailing 0s are excluded in the encoding
320		* of the bitstring. Trailing 0s are considered part of the 'unused' bits
321		* when encoding this value in the first content octet
322		*/
323	0	if (bits != 0) {
324	0	cur_byte = buf + byte_len - 1;
325	0	cur_byte_shifted = *cur_byte >> unused_bits;
326
327	0	for (;;) {
328	0	bit = cur_byte_shifted & 0x1;
329	0	cur_byte_shifted >>= 1;
330
331	0	if (bit != 0) {
332	0	break;
333	0	}
334
335	0	bits--;
336	0	if (bits == 0) {
337	0	break;
338	0	}
339
340	0	if (bits % 8 == 0) {
341	0	cur_byte_shifted = *--cur_byte;
342	0	}
343	0	}
344	0	}
345
346	0	return mbedtls_asn1_write_bitstring(p, start, buf, bits);
347	0	}
348
349		int mbedtls_asn1_write_bitstring(unsigned char *p, unsigned char start,
350		const unsigned char *buf, size_t bits)
351	0	{
352	0	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
353	0	size_t len = 0;
354	0	size_t unused_bits, byte_len;
355
356	0	byte_len = (bits + 7) / 8;
357	0	unused_bits = (byte_len * 8) - bits;
358
359	0	if (p < start \|\| (size_t) (p - start) < byte_len + 1) {
360	0	return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
361	0	}
362
363	0	len = byte_len + 1;
364
365		/* Write the bitstring. Ensure the unused bits are zeroed */
366	0	if (byte_len > 0) {
367	0	byte_len--;
368	0	--(p) = buf[byte_len] & ~((0x1 << unused_bits) - 1);
369	0	(*p) -= byte_len;
370	0	memcpy(*p, buf, byte_len);
371	0	}
372
373		/* Write unused bits */
374	0	--(p) = (unsigned char) unused_bits;
375
376	0	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
377	0	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_BIT_STRING));
378
379	0	return (int) len;
380	0	}
381
382		int mbedtls_asn1_write_octet_string(unsigned char *p, unsigned char start,
383		const unsigned char *buf, size_t size)
384	0	{
385	0	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
386	0	size_t len = 0;
387
388	0	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_raw_buffer(p, start, buf, size));
389
390	0	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
391	0	MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_OCTET_STRING));
392
393	0	return (int) len;
394	0	}
395
396
397		/* This is a copy of the ASN.1 parsing function mbedtls_asn1_find_named_data(),
398		* which is replicated to avoid a dependency ASN1_WRITE_C on ASN1_PARSE_C. */
399		static mbedtls_asn1_named_data *asn1_find_named_data(
400		mbedtls_asn1_named_data *list,
401		const char *oid, size_t len)
402	0	{
403	0	while (list != NULL) {
404	0	if (list->oid.len == len &&
405	0	memcmp(list->oid.p, oid, len) == 0) {
406	0	break;
407	0	}
408
409	0	list = list->next;
410	0	}
411
412	0	return list;
413	0	}
414
415		mbedtls_asn1_named_data *mbedtls_asn1_store_named_data(
416		mbedtls_asn1_named_data **head,
417		const char *oid, size_t oid_len,
418		const unsigned char *val,
419		size_t val_len)
420	0	{
421	0	mbedtls_asn1_named_data *cur;
422
423	0	if ((cur = asn1_find_named_data(*head, oid, oid_len)) == NULL) {
424		// Add new entry if not present yet based on OID
425		//
426	0	cur = (mbedtls_asn1_named_data *) mbedtls_calloc(1,
427	0	sizeof(mbedtls_asn1_named_data));
428	0	if (cur == NULL) {
429	0	return NULL;
430	0	}
431
432	0	cur->oid.len = oid_len;
433	0	cur->oid.p = mbedtls_calloc(1, oid_len);
434	0	if (cur->oid.p == NULL) {
435	0	mbedtls_free(cur);
436	0	return NULL;
437	0	}
438
439	0	memcpy(cur->oid.p, oid, oid_len);
440
441	0	cur->val.len = val_len;
442	0	if (val_len != 0) {
443	0	cur->val.p = mbedtls_calloc(1, val_len);
444	0	if (cur->val.p == NULL) {
445	0	mbedtls_free(cur->oid.p);
446	0	mbedtls_free(cur);
447	0	return NULL;
448	0	}
449	0	}
450
451	0	cur->next = *head;
452	0	*head = cur;
453	0	} else if (val_len == 0) {
454	0	mbedtls_free(cur->val.p);
455	0	cur->val.p = NULL;
456	0	} else if (cur->val.len != val_len) {
457		/*
458		* Enlarge existing value buffer if needed
459		* Preserve old data until the allocation succeeded, to leave list in
460		* a consistent state in case allocation fails.
461		*/
462	0	void *p = mbedtls_calloc(1, val_len);
463	0	if (p == NULL) {
464	0	return NULL;
465	0	}
466
467	0	mbedtls_free(cur->val.p);
468	0	cur->val.p = p;
469	0	cur->val.len = val_len;
470	0	}
471
472	0	if (val != NULL && val_len != 0) {
473	0	memcpy(cur->val.p, val, val_len);
474	0	}
475
476	0	return cur;
477	0	}
478		#endif /* MBEDTLS_ASN1_WRITE_C */