/* BEGIN_HEADER */
#include <errno.h>
#include <stdlib.h>
#include <limits.h>

#include "mbedtls/private/bignum.h"
#include "mbedtls/asn1.h"
#if defined(MBEDTLS_ASN1_WRITE_C)
#include "mbedtls/asn1write.h"
#endif

/* Used internally to report an error that indicates a bug in a parsing function. */
#define ERR_PARSE_INCONSISTENCY INT_MAX

/* Use this magic value in some tests to indicate that the expected result
 * should not be checked. */
#define UNPREDICTABLE_RESULT 0x5552

static int nested_parse(unsigned char **const p,
                        const unsigned char *const end)
{
    int ret;
    size_t len = 0;
    size_t len2 = 0;
    unsigned char *const start = *p;
    unsigned char *content_start;
    unsigned char tag;

    /* First get the length, skipping over the tag. */
    content_start = start + 1;
    ret = mbedtls_asn1_get_len(&content_start, end, &len);
    TEST_ASSERT(content_start <= end);
    if (ret != 0) {
        return ret;
    }

    /* Since we have a valid element start (tag and length), retrieve and
     * check the tag. */
    tag = start[0];
    TEST_EQUAL(mbedtls_asn1_get_tag(p, end, &len2, tag ^ 1),
               MBEDTLS_ERR_ASN1_UNEXPECTED_TAG);
    *p = start;
    TEST_EQUAL(mbedtls_asn1_get_tag(p, end, &len2, tag), 0);
    TEST_EQUAL(len, len2);
    TEST_ASSERT(*p == content_start);
    *p = content_start;

    switch (tag & 0x1f) {
        case MBEDTLS_ASN1_BOOLEAN:
        {
            int val = -257;
            *p = start;
            ret = mbedtls_asn1_get_bool(p, end, &val);
            if (ret == 0) {
                TEST_ASSERT(val == 0 || val == 1);
            }
            break;
        }

        case MBEDTLS_ASN1_INTEGER:
        {
#if defined(MBEDTLS_BIGNUM_C)
            mbedtls_mpi mpi;
            mbedtls_mpi_init(&mpi);
            *p = start;
            ret = mbedtls_asn1_get_mpi(p, end, &mpi);
            mbedtls_mpi_free(&mpi);
#else
            *p = start + 1;
            ret = mbedtls_asn1_get_len(p, end, &len);
            *p += len;
#endif
            /* If we're sure that the number fits in an int, also
             * call mbedtls_asn1_get_int(). */
            if (ret == 0 && len < sizeof(int)) {
                int val = -257;
                unsigned char *q = start;
                ret = mbedtls_asn1_get_int(&q, end, &val);
                TEST_ASSERT(*p == q);
            }
            break;
        }

        case MBEDTLS_ASN1_BIT_STRING:
        {
            mbedtls_asn1_bitstring bs;
            *p = start;
            ret = mbedtls_asn1_get_bitstring(p, end, &bs);
            break;
        }

        case MBEDTLS_ASN1_SEQUENCE:
        {
            while (*p <= end && *p < content_start + len && ret == 0) {
                ret = nested_parse(p, content_start + len);
            }
            break;
        }

        case MBEDTLS_ASN1_OCTET_STRING:
        case MBEDTLS_ASN1_NULL:
        case MBEDTLS_ASN1_OID:
        case MBEDTLS_ASN1_UTF8_STRING:
        case MBEDTLS_ASN1_SET:
        case MBEDTLS_ASN1_PRINTABLE_STRING:
        case MBEDTLS_ASN1_T61_STRING:
        case MBEDTLS_ASN1_IA5_STRING:
        case MBEDTLS_ASN1_UTC_TIME:
        case MBEDTLS_ASN1_GENERALIZED_TIME:
        case MBEDTLS_ASN1_UNIVERSAL_STRING:
        case MBEDTLS_ASN1_BMP_STRING:
        default:
            /* No further testing implemented for this tag. */
            *p += len;
            return 0;
    }

    TEST_ASSERT(*p <= end);
    return ret;

exit:
    return ERR_PARSE_INCONSISTENCY;
}

static int get_len_step(const data_t *input, size_t buffer_size,
                        size_t actual_length)
{
    unsigned char *buf = NULL;
    unsigned char *p = NULL;
    unsigned char *end;
    size_t parsed_length;
    int ret;

    mbedtls_test_set_step(buffer_size);
    /* Allocate a new buffer of exactly the length to parse each time.
     * This gives memory sanitizers a chance to catch buffer overreads. */
    if (buffer_size == 0) {
        TEST_CALLOC(buf, 1);
        end = buf + 1;
        p = end;
    } else {
        TEST_CALLOC_OR_SKIP(buf, buffer_size);
        if (buffer_size > input->len) {
            memcpy(buf, input->x, input->len);
            memset(buf + input->len, 'A', buffer_size - input->len);
        } else {
            memcpy(buf, input->x, buffer_size);
        }
        p = buf;
        end = buf + buffer_size;
    }

    ret = mbedtls_asn1_get_len(&p, end, &parsed_length);

    if (buffer_size >= input->len + actual_length) {
        TEST_EQUAL(ret, 0);
        TEST_ASSERT(p == buf + input->len);
        TEST_EQUAL(parsed_length, actual_length);
    } else {
        TEST_EQUAL(ret, MBEDTLS_ERR_ASN1_OUT_OF_DATA);
    }
    mbedtls_free(buf);
    return 1;

exit:
    mbedtls_free(buf);
    return 0;
}

typedef struct {
    const unsigned char *input_start;
    const char *description;
} traverse_state_t;

/* Value returned by traverse_callback if description runs out. */
#define RET_TRAVERSE_STOP 1
/* Value returned by traverse_callback if description has an invalid format
 * (see traverse_sequence_of). */
#define RET_TRAVERSE_ERROR 2


static int traverse_callback(void *ctx, int tag,
                             unsigned char *content, size_t len)
{
    traverse_state_t *state = ctx;
    size_t offset;
    const char *rest = state->description;
    unsigned long n;

    TEST_ASSERT(content > state->input_start);
    offset = content - state->input_start;
    mbedtls_test_set_step(offset);

    if (*rest == 0) {
        return RET_TRAVERSE_STOP;
    }
    n = strtoul(rest, (char **) &rest, 0);
    TEST_EQUAL(n, offset);
    TEST_EQUAL(*rest, ',');
    ++rest;
    n = strtoul(rest, (char **) &rest, 0);
    TEST_EQUAL(n, (unsigned) tag);
    TEST_EQUAL(*rest, ',');
    ++rest;
    n = strtoul(rest, (char **) &rest, 0);
    TEST_EQUAL(n, len);
    if (*rest == ',') {
        ++rest;
    }

    state->description = rest;
    return 0;

exit:
    return RET_TRAVERSE_ERROR;
}

/* END_HEADER */

/* BEGIN_DEPENDENCIES
 * depends_on:MBEDTLS_ASN1_PARSE_C
 * END_DEPENDENCIES
 */

/* BEGIN_CASE */
void parse_prefixes(const data_t *input,
                    int full_result,
                    int overfull_result)
{
    /* full_result: expected result from parsing the given string. */
    /* overfull_result: expected_result from parsing the given string plus
     * some trailing garbage. This may be UNPREDICTABLE_RESULT to accept
     * any result: use this for invalid inputs that may or may not become
     * valid depending on what the trailing garbage is. */

    unsigned char *buf = NULL;
    unsigned char *p = NULL;
    size_t buffer_size;
    int ret;

    /* Test every prefix of the input, except the empty string.
     * The first byte of the string is the tag. Without a tag byte,
     * we wouldn't know what to parse the input as.
     * Also test the input followed by an extra byte.
     */
    for (buffer_size = 1; buffer_size <= input->len + 1; buffer_size++) {
        mbedtls_test_set_step(buffer_size);
        /* Allocate a new buffer of exactly the length to parse each time.
         * This gives memory sanitizers a chance to catch buffer overreads. */
        TEST_CALLOC(buf, buffer_size);
        memcpy(buf, input->x, buffer_size);
        p = buf;
        ret = nested_parse(&p, buf + buffer_size);

        if (ret == ERR_PARSE_INCONSISTENCY) {
            goto exit;
        }
        if (buffer_size < input->len) {
            TEST_EQUAL(ret, MBEDTLS_ERR_ASN1_OUT_OF_DATA);
        } else if (buffer_size == input->len) {
            TEST_EQUAL(ret, full_result);
        } else { /* ( buffer_size > input->len ) */
            if (overfull_result != UNPREDICTABLE_RESULT) {
                TEST_EQUAL(ret, overfull_result);
            }
        }
        if (ret == 0) {
            TEST_ASSERT(p == buf + input->len);
        }

        mbedtls_free(buf);
        buf = NULL;
    }

exit:
    mbedtls_free(buf);
}
/* END_CASE */

/* BEGIN_CASE */
void get_len(const data_t *input, int actual_length_arg)
{
    size_t actual_length = actual_length_arg;
    size_t buffer_size;

    /* Test prefixes of a buffer containing the given length string
     * followed by `actual_length` bytes of payload. To save a bit of
     * time, we skip some "boring" prefixes: we don't test prefixes where
     * the payload is truncated more than one byte away from either end,
     * and we only test the empty string on a 1-byte input.
     */
    for (buffer_size = 1; buffer_size <= input->len + 1; buffer_size++) {
        if (!get_len_step(input, buffer_size, actual_length)) {
            goto exit;
        }
    }
    if (!get_len_step(input, input->len + actual_length - 1, actual_length)) {
        goto exit;
    }
    if (!get_len_step(input, input->len + actual_length, actual_length)) {
        goto exit;
    }
}
/* END_CASE */

/* BEGIN_CASE */
void get_boolean(const data_t *input,
                 int expected_value, int expected_result)
{
    unsigned char *p = input->x;
    int val;
    int ret;
    ret = mbedtls_asn1_get_bool(&p, input->x + input->len, &val);
    TEST_EQUAL(ret, expected_result);
    if (expected_result == 0) {
        TEST_EQUAL(val, expected_value);
        TEST_ASSERT(p == input->x + input->len);
    }
}
/* END_CASE */

/* BEGIN_CASE */
void empty_integer(const data_t *input)
{
    unsigned char *p;
#if defined(MBEDTLS_BIGNUM_C)
    mbedtls_mpi actual_mpi;
#endif
    int val;

#if defined(MBEDTLS_BIGNUM_C)
    mbedtls_mpi_init(&actual_mpi);
#endif

    /* An INTEGER with no content is not valid. */
    p = input->x;
    TEST_EQUAL(mbedtls_asn1_get_int(&p, input->x + input->len, &val),
               MBEDTLS_ERR_ASN1_INVALID_LENGTH);

#if defined(MBEDTLS_BIGNUM_C)
    /* INTEGERs are sometimes abused as bitstrings, so the library accepts
     * an INTEGER with empty content and gives it the value 0. */
    p = input->x;
    TEST_EQUAL(mbedtls_asn1_get_mpi(&p, input->x + input->len, &actual_mpi),
               0);
    TEST_EQUAL(mbedtls_mpi_cmp_int(&actual_mpi, 0), 0);
#endif

exit:
#if defined(MBEDTLS_BIGNUM_C)
    mbedtls_mpi_free(&actual_mpi);
#endif
    /*empty cleanup in some configurations*/;
}
/* END_CASE */

/* BEGIN_CASE */
void get_integer(const data_t *input,
                 const char *expected_hex, int expected_result)
{
    unsigned char *p;
#if defined(MBEDTLS_BIGNUM_C)
    mbedtls_mpi expected_mpi;
    mbedtls_mpi actual_mpi;
    mbedtls_mpi complement;
    int expected_result_for_mpi = expected_result;
#endif
    long expected_value;
    int expected_result_for_int = expected_result;
    int val;
    int ret;

#if defined(MBEDTLS_BIGNUM_C)
    mbedtls_mpi_init(&expected_mpi);
    mbedtls_mpi_init(&actual_mpi);
    mbedtls_mpi_init(&complement);
#endif

    errno = 0;
    expected_value = strtol(expected_hex, NULL, 16);
    if (expected_result == 0 &&
        (errno == ERANGE
#if LONG_MAX > INT_MAX
         || expected_value > INT_MAX || expected_value < INT_MIN
#endif
        )) {
        /* The library returns the dubious error code INVALID_LENGTH
         * for integers that are out of range. */
        expected_result_for_int = MBEDTLS_ERR_ASN1_INVALID_LENGTH;
    }
    if (expected_result == 0 && expected_value < 0) {
        /* The library does not support negative INTEGERs and
         * returns the dubious error code INVALID_LENGTH.
         * Test that we preserve the historical behavior. If we
         * decide to change the behavior, we'll also change this test. */
        expected_result_for_int = MBEDTLS_ERR_ASN1_INVALID_LENGTH;
    }

    p = input->x;
    ret = mbedtls_asn1_get_int(&p, input->x + input->len, &val);
    TEST_EQUAL(ret, expected_result_for_int);
    if (ret == 0) {
        TEST_EQUAL(val, expected_value);
        TEST_ASSERT(p == input->x + input->len);
    }

#if defined(MBEDTLS_BIGNUM_C)
    ret = mbedtls_test_read_mpi(&expected_mpi, expected_hex);
    TEST_ASSERT(ret == 0 || ret == MBEDTLS_ERR_MPI_BAD_INPUT_DATA);
    if (ret == MBEDTLS_ERR_MPI_BAD_INPUT_DATA) {
        /* The data overflows the maximum MPI size. */
        expected_result_for_mpi = MBEDTLS_ERR_MPI_BAD_INPUT_DATA;
    }
    p = input->x;
    ret = mbedtls_asn1_get_mpi(&p, input->x + input->len, &actual_mpi);
    TEST_EQUAL(ret, expected_result_for_mpi);
    if (ret == 0) {
        if (expected_value >= 0) {
            TEST_ASSERT(mbedtls_mpi_cmp_mpi(&actual_mpi,
                                            &expected_mpi) == 0);
        } else {
            /* The library ignores the sign bit in ASN.1 INTEGERs
             * (which makes sense insofar as INTEGERs are sometimes
             * abused as bit strings), so the result of parsing them
             * is a positive integer such that expected_mpi +
             * actual_mpi = 2^n where n is the length of the content
             * of the INTEGER. (Leading ff octets don't matter for the
             * expected value, but they matter for the actual value.)
             * Test that we don't change from this behavior. If we
             * decide to fix the library to change the behavior on
             * negative INTEGERs, we'll fix this test code. */
            unsigned char *q = input->x + 1;
            size_t len;
            TEST_ASSERT(mbedtls_asn1_get_len(&q, input->x + input->len,
                                             &len) == 0);
            TEST_ASSERT(mbedtls_mpi_lset(&complement, 1) == 0);
            TEST_ASSERT(mbedtls_mpi_shift_l(&complement, len * 8) == 0);
            TEST_ASSERT(mbedtls_mpi_add_mpi(&complement, &complement,
                                            &expected_mpi) == 0);
            TEST_ASSERT(mbedtls_mpi_cmp_mpi(&complement,
                                            &actual_mpi) == 0);
        }
        TEST_ASSERT(p == input->x + input->len);
    }
#endif

exit:
#if defined(MBEDTLS_BIGNUM_C)
    mbedtls_mpi_free(&expected_mpi);
    mbedtls_mpi_free(&actual_mpi);
    mbedtls_mpi_free(&complement);
#endif
    /*empty cleanup in some configurations*/;
}
/* END_CASE */

/* BEGIN_CASE */
/**
 * The #asn1_data_length argument is only used to provide real data length,
 * not the buffer length, in case there are more bytes in the buffer, than there
 * is data, it is then compared with the difference of initial p, and p after the
 * #mbedtls_asn1_get_integer() call
 */
void get_integer_raw(const data_t *input,
                     const data_t *expected_output, int expected_result,
                     int asn1_data_length)
{
    int ret;
    unsigned char *p = input->x;

    if (asn1_data_length == -1) {
        asn1_data_length = input->len;
    }

    /* Initialize pointer and length to nonsense values so that we can
     * distinguish leaving them unchanged from setting them in the error
     * case. */
    unsigned char dummy = 0;
    unsigned char *integer_head = &dummy;
    size_t integer_length = 0xdeadbeef;

    ret = mbedtls_asn1_get_integer(&p, input->x + input->len,
                                   &integer_head, &integer_length);

    TEST_EQUAL(ret, expected_result);

    if (expected_result == 0) {
        /* On success, check that the returned number matches what we expect */
        TEST_MEMORY_COMPARE(expected_output->x, expected_output->len,
                            integer_head, integer_length);

        /* And check that p is correct */
        TEST_EQUAL(p - input->x, asn1_data_length);
    } else {
        /* On failure we'd like the pointer and length to be
         * obviously invalid */
        TEST_ASSERT(integer_head == NULL);
        TEST_EQUAL(integer_length, 0);

        /* We'd also like p not to have advanced at all */
        TEST_ASSERT(p == input->x);
    }
}
/* END_CASE */

/* BEGIN_CASE */
void get_enum(const data_t *input,
              const char *expected_hex, int expected_result)
{
    unsigned char *p;
    long expected_value;
    int expected_result_for_enum = expected_result;
    int val;
    int ret;

    errno = 0;
    expected_value = strtol(expected_hex, NULL, 16);
    if (expected_result == 0 &&
        (errno == ERANGE
#if LONG_MAX > INT_MAX
         || expected_value > INT_MAX || expected_value < INT_MIN
#endif
        )) {
        /* The library returns the dubious error code INVALID_LENGTH
         * for integers that are out of range. */
        expected_result_for_enum = MBEDTLS_ERR_ASN1_INVALID_LENGTH;
    }
    if (expected_result == 0 && expected_value < 0) {
        /* The library does not support negative INTEGERs and
         * returns the dubious error code INVALID_LENGTH.
         * Test that we preserve the historical behavior. If we
         * decide to change the behavior, we'll also change this test. */
        expected_result_for_enum = MBEDTLS_ERR_ASN1_INVALID_LENGTH;
    }

    p = input->x;
    ret = mbedtls_asn1_get_enum(&p, input->x + input->len, &val);
    TEST_EQUAL(ret, expected_result_for_enum);
    if (ret == 0) {
        TEST_EQUAL(val, expected_value);
        TEST_ASSERT(p == input->x + input->len);
    }
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_BIGNUM_C */
void get_mpi_too_large()
{
    unsigned char *buf = NULL;
    unsigned char *p;
    mbedtls_mpi actual_mpi;
    size_t too_many_octets =
        MBEDTLS_MPI_MAX_LIMBS * sizeof(mbedtls_mpi_uint) + 1;
    size_t size = too_many_octets + 6;

    mbedtls_mpi_init(&actual_mpi);

    TEST_CALLOC(buf, size);
    buf[0] = 0x02; /* tag: INTEGER */
    buf[1] = 0x84; /* 4-octet length */
    buf[2] = (too_many_octets >> 24) & 0xff;
    buf[3] = (too_many_octets >> 16) & 0xff;
    buf[4] = (too_many_octets >> 8) & 0xff;
    buf[5] = too_many_octets & 0xff;
    buf[6] = 0x01; /* most significant octet */

    p = buf;
    TEST_EQUAL(mbedtls_asn1_get_mpi(&p, buf + size, &actual_mpi),
               MBEDTLS_ERR_MPI_ALLOC_FAILED);

exit:
    mbedtls_mpi_free(&actual_mpi);
    mbedtls_free(buf);
}
/* END_CASE */

/* BEGIN_CASE */
void get_bitstring(const data_t *input,
                   int expected_length, int expected_unused_bits,
                   int expected_result, int expected_result_null)
{
    mbedtls_asn1_bitstring bs = { 0xdead, 0x21, NULL };
    unsigned char *p = input->x;

    TEST_EQUAL(mbedtls_asn1_get_bitstring(&p, input->x + input->len, &bs),
               expected_result);
    if (expected_result == 0) {
        TEST_EQUAL(bs.len, (size_t) expected_length);
        TEST_EQUAL(bs.unused_bits, expected_unused_bits);
        TEST_ASSERT(bs.p != NULL);
        TEST_EQUAL(bs.p - input->x + bs.len, input->len);
        TEST_ASSERT(p == input->x + input->len);
    }

    p = input->x;
    TEST_EQUAL(mbedtls_asn1_get_bitstring_null(&p, input->x + input->len,
                                               &bs.len),
               expected_result_null);
    if (expected_result_null == 0) {
        TEST_EQUAL(bs.len, (size_t) expected_length);
        if (expected_result == 0) {
            TEST_ASSERT(p == input->x + input->len - bs.len);
        }
    }
}
/* END_CASE */

/* BEGIN_CASE */
void get_sequence_of(const data_t *input, int tag,
                     const char *description,
                     int expected_result)
{
    /* The description string is a comma-separated list of integers.
     * For each element in the SEQUENCE in input, description contains
     * two integers: the offset of the element (offset from the start
     * of input to the tag of the element) and the length of the
     * element's contents.
     * "offset1,length1,..." */

    mbedtls_asn1_sequence head = { { 0, 0, NULL }, NULL };
    mbedtls_asn1_sequence *cur;
    unsigned char *p = input->x;
    const char *rest = description;
    unsigned long n;
    unsigned int step = 0;

    TEST_EQUAL(mbedtls_asn1_get_sequence_of(&p, input->x + input->len,
                                            &head, tag),
               expected_result);
    if (expected_result == 0) {
        TEST_ASSERT(p == input->x + input->len);

        if (!*rest) {
            TEST_EQUAL(head.buf.tag, 0);
            TEST_ASSERT(head.buf.p == NULL);
            TEST_EQUAL(head.buf.len, 0);
            TEST_ASSERT(head.next == NULL);
        } else {
            cur = &head;
            while (*rest) {
                mbedtls_test_set_step(step);
                TEST_ASSERT(cur != NULL);
                TEST_EQUAL(cur->buf.tag, tag);
                n = strtoul(rest, (char **) &rest, 0);
                TEST_EQUAL(n, (size_t) (cur->buf.p - input->x));
                ++rest;
                n = strtoul(rest, (char **) &rest, 0);
                TEST_EQUAL(n, cur->buf.len);
                if (*rest) {
                    ++rest;
                }
                cur = cur->next;
                ++step;
            }
            TEST_ASSERT(cur == NULL);
        }
    }

exit:
    mbedtls_asn1_sequence_free(head.next);
}
/* END_CASE */

/* BEGIN_CASE */
void traverse_sequence_of(const data_t *input,
                          int tag_must_mask, int tag_must_val,
                          int tag_may_mask, int tag_may_val,
                          const char *description,
                          int expected_result)
{
    /* The description string is a comma-separated list of integers.
     * For each element in the SEQUENCE in input, description contains
     * three integers: the offset of the element's content (offset from
     * the start of input to the content of the element), the element's tag,
     * and the length of the element's contents.
     * "offset1,tag1,length1,..." */

    unsigned char *p = input->x;
    traverse_state_t traverse_state = { input->x, description };
    int ret;

    ret = mbedtls_asn1_traverse_sequence_of(&p, input->x + input->len,
                                            (uint8_t) tag_must_mask, (uint8_t) tag_must_val,
                                            (uint8_t) tag_may_mask, (uint8_t) tag_may_val,
                                            traverse_callback, &traverse_state);
    if (ret == RET_TRAVERSE_ERROR) {
        goto exit;
    }
    TEST_EQUAL(ret, expected_result);
    TEST_EQUAL(*traverse_state.description, 0);
}
/* END_CASE */

/* BEGIN_CASE */
void get_alg(const data_t *input,
             int oid_offset, int oid_length,
             int params_tag, int params_offset, int params_length,
             int total_length,
             int expected_result)
{
    mbedtls_asn1_buf oid = { -1, 0, NULL };
    mbedtls_asn1_buf params = { -1, 0, NULL };
    unsigned char *p = input->x;
    int ret;

    TEST_EQUAL(mbedtls_asn1_get_alg(&p, input->x + input->len,
                                    &oid, &params),
               expected_result);
    if (expected_result == 0) {
        TEST_EQUAL(oid.tag, MBEDTLS_ASN1_OID);
        TEST_EQUAL(oid.p - input->x, oid_offset);
        TEST_EQUAL(oid.len, (size_t) oid_length);
        TEST_EQUAL(params.tag, params_tag);
        if (params_offset != 0) {
            TEST_EQUAL(params.p - input->x, params_offset);
        } else {
            TEST_ASSERT(params.p == NULL);
        }
        TEST_EQUAL(params.len, (size_t) params_length);
        TEST_EQUAL(p - input->x, total_length);
    }

    ret = mbedtls_asn1_get_alg_null(&p, input->x + input->len, &oid);
    if (expected_result == 0 && params_offset == 0) {
        TEST_EQUAL(oid.tag, MBEDTLS_ASN1_OID);
        TEST_EQUAL(oid.p - input->x, oid_offset);
        TEST_EQUAL(oid.len, (size_t) oid_length);
        TEST_EQUAL(p - input->x, total_length);
    } else {
        TEST_ASSERT(ret != 0);
    }
}
/* END_CASE */

/* BEGIN_CASE */
void find_named_data(data_t *oid0, data_t *oid1, data_t *oid2, data_t *oid3,
                     data_t *needle, int from, int position)
{
    mbedtls_asn1_named_data nd[] = {
        { { 0x06, oid0->len, oid0->x }, { 0, 0, NULL }, NULL, 0 },
        { { 0x06, oid1->len, oid1->x }, { 0, 0, NULL }, NULL, 0 },
        { { 0x06, oid2->len, oid2->x }, { 0, 0, NULL }, NULL, 0 },
        { { 0x06, oid3->len, oid3->x }, { 0, 0, NULL }, NULL, 0 },
    };
    mbedtls_asn1_named_data *pointers[ARRAY_LENGTH(nd) + 1];
    size_t i;
    const mbedtls_asn1_named_data *found;

    for (i = 0; i < ARRAY_LENGTH(nd); i++) {
        pointers[i] = &nd[i];
    }
    pointers[ARRAY_LENGTH(nd)] = NULL;
    for (i = 0; i < ARRAY_LENGTH(nd); i++) {
        nd[i].next = pointers[i+1];
    }

    found = mbedtls_asn1_find_named_data((const mbedtls_asn1_named_data *) pointers[from],
                                         (const char *) needle->x,
                                         needle->len);
    TEST_ASSERT(found == pointers[position]);
}
/* END_CASE */

/* BEGIN_CASE */
void free_named_data_list(int length)
{
    mbedtls_asn1_named_data *head = NULL;
    int i;

    for (i = 0; i < length; i++) {
        mbedtls_asn1_named_data *new = NULL;
        TEST_CALLOC(new, 1);
        new->next = head;
        head = new;
    }

    mbedtls_asn1_free_named_data_list(&head);
    TEST_ASSERT(head == NULL);
    /* Most of the point of the test is that it doesn't leak memory.
     * So this test is only really useful under a memory leak detection
     * framework. */
exit:
    mbedtls_asn1_free_named_data_list(&head);
}
/* END_CASE */
