doubao_chat/lib/net/mbedtls_2_2_1/library/asn1parse.c

/*
 *  Generic ASN.1 parsing
 *
 *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
 *  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.
 *
 *  This file is part of mbed TLS (https://tls.mbed.org)
 */

#if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/mbedtls_config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif

#if defined(MBEDTLS_ASN1_PARSE_C)

#include "mbedtls/asn1.h"

#include <string.h>

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

#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
#else
#include <stdlib.h>
#define mbedtls_calloc    calloc
#define mbedtls_free       free
#endif

/* Implementation that should never be optimized out by the compiler */
static void mbedtls_zeroize(void *v, size_t n)
{
    volatile unsigned char *p = (unsigned char *)v;
    while (n--) {
        *p++ = 0;
    }
}

/*
 * 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;
    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);
}

int mbedtls_asn1_get_int(unsigned char **p,
                         const unsigned char *end,
                         int *val)
{
    int ret;
    size_t len;

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

    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);
}

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

    /* 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);
}

/*
 * 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;

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

    if ((*len)-- < 2 || *(*p)++ != 0) {
        return (MBEDTLS_ERR_ASN1_INVALID_DATA);
    }

    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)
{
    int ret;
    size_t len;
    mbedtls_asn1_buf *buf;

    /* 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) {
        buf = &(cur->buf);
        buf->tag = **p;

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

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

        /* Allocate and assign next pointer */
        if (*p < end) {
            cur->next = (mbedtls_asn1_sequence *)mbedtls_calloc(1,
                        sizeof(mbedtls_asn1_sequence));

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

            cur = cur->next;
        }
    }

    /* Set final sequence entry's next pointer to NULL */
    cur->next = NULL;

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

    return (0);
}

int mbedtls_asn1_get_alg(unsigned char **p,
                         const unsigned char *end,
                         mbedtls_asn1_buf *alg, mbedtls_asn1_buf *params)
{
    int ret;
    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_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_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);
}

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_zeroize(cur, sizeof(mbedtls_asn1_named_data));
}

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_asn1_free_named_data(cur);
        mbedtls_free(cur);
    }
}

mbedtls_asn1_named_data *mbedtls_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);
}

#endif /* MBEDTLS_ASN1_PARSE_C */