mbedtls/tests/suites/test_suite_asn1write.function

/* BEGIN_HEADER */
#include "mbedtls/asn1write.h"

#define GUARD_LEN 4
#define GUARD_VAL 0x2a

typedef struct {
    unsigned char *output;
    unsigned char *start;
    unsigned char *end;
    unsigned char *p;
    size_t size;
} generic_write_data_t;

int generic_write_start_step(generic_write_data_t *data)
{
    mbedtls_test_set_step(data->size);
    mbedtls_free(data->output);
    data->output = NULL;
    ASSERT_ALLOC(data->output, data->size == 0 ? 1 : data->size);
    data->end = data->output + data->size;
    data->p = data->end;
    data->start = data->end - data->size;
    return 1;
exit:
    return 0;
}

int generic_write_finish_step(generic_write_data_t *data,
                              const data_t *expected, int ret)
{
    int ok = 0;

    if (data->size < expected->len) {
        TEST_EQUAL(ret, MBEDTLS_ERR_ASN1_BUF_TOO_SMALL);
    } else {
        TEST_EQUAL(ret, data->end - data->p);
        TEST_ASSERT(data->p >= data->start);
        TEST_ASSERT(data->p <= data->end);
        ASSERT_COMPARE(data->p, (size_t) (data->end - data->p),
                       expected->x, expected->len);
    }
    ok = 1;

exit:
    return ok;
}

/* END_HEADER */

/* BEGIN_DEPENDENCIES
 * depends_on:MBEDTLS_ASN1_WRITE_C
 * END_DEPENDENCIES
 */

/* BEGIN_CASE */
void mbedtls_asn1_write_null(data_t *expected)
{
    generic_write_data_t data = { NULL, NULL, NULL, NULL, 0 };
    int ret;

    for (data.size = 0; data.size <= expected->len + 1; data.size++) {
        if (!generic_write_start_step(&data)) {
            goto exit;
        }
        ret = mbedtls_asn1_write_null(&data.p, data.start);
        if (!generic_write_finish_step(&data, expected, ret)) {
            goto exit;
        }
        /* There's no parsing function for NULL. */
    }

exit:
    mbedtls_free(data.output);
}
/* END_CASE */

/* BEGIN_CASE */
void mbedtls_asn1_write_bool(int val, data_t *expected)
{
    generic_write_data_t data = { NULL, NULL, NULL, NULL, 0 };
    int ret;

    for (data.size = 0; data.size <= expected->len + 1; data.size++) {
        if (!generic_write_start_step(&data)) {
            goto exit;
        }
        ret = mbedtls_asn1_write_bool(&data.p, data.start, val);
        if (!generic_write_finish_step(&data, expected, ret)) {
            goto exit;
        }
#if defined(MBEDTLS_ASN1_PARSE_C)
        if (ret >= 0) {
            int read = 0xdeadbeef;
            TEST_EQUAL(mbedtls_asn1_get_bool(&data.p, data.end, &read), 0);
            TEST_EQUAL(val, read);
        }
#endif /* MBEDTLS_ASN1_PARSE_C */
    }

exit:
    mbedtls_free(data.output);
}
/* END_CASE */

/* BEGIN_CASE */
void mbedtls_asn1_write_int(int val, data_t *expected)
{
    generic_write_data_t data = { NULL, NULL, NULL, NULL, 0 };
    int ret;

    for (data.size = 0; data.size <= expected->len + 1; data.size++) {
        if (!generic_write_start_step(&data)) {
            goto exit;
        }
        ret = mbedtls_asn1_write_int(&data.p, data.start, val);
        if (!generic_write_finish_step(&data, expected, ret)) {
            goto exit;
        }
#if defined(MBEDTLS_ASN1_PARSE_C)
        if (ret >= 0) {
            int read = 0xdeadbeef;
            TEST_EQUAL(mbedtls_asn1_get_int(&data.p, data.end, &read), 0);
            TEST_EQUAL(val, read);
        }
#endif /* MBEDTLS_ASN1_PARSE_C */
    }

exit:
    mbedtls_free(data.output);
}
/* END_CASE */


/* BEGIN_CASE */
void mbedtls_asn1_write_enum(int val, data_t *expected)
{
    generic_write_data_t data = { NULL, NULL, NULL, NULL, 0 };
    int ret;

    for (data.size = 0; data.size <= expected->len + 1; data.size++) {
        if (!generic_write_start_step(&data)) {
            goto exit;
        }
        ret = mbedtls_asn1_write_enum(&data.p, data.start, val);
        if (!generic_write_finish_step(&data, expected, ret)) {
            goto exit;
        }
#if defined(MBEDTLS_ASN1_PARSE_C)
        if (ret >= 0) {
            int read = 0xdeadbeef;
            TEST_EQUAL(mbedtls_asn1_get_enum(&data.p, data.end, &read), 0);
            TEST_EQUAL(val, read);
        }
#endif /* MBEDTLS_ASN1_PARSE_C */
    }

exit:
    mbedtls_free(data.output);
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_BIGNUM_C */
void mbedtls_asn1_write_mpi(data_t *val, data_t *expected)
{
    generic_write_data_t data = { NULL, NULL, NULL, NULL, 0 };
    mbedtls_mpi mpi, read;
    int ret;

    mbedtls_mpi_init(&mpi);
    mbedtls_mpi_init(&read);
    TEST_ASSERT(mbedtls_mpi_read_binary(&mpi, val->x, val->len) == 0);

    for (data.size = 0; data.size <= expected->len + 1; data.size++) {
        if (!generic_write_start_step(&data)) {
            goto exit;
        }
        ret = mbedtls_asn1_write_mpi(&data.p, data.start, &mpi);
        if (!generic_write_finish_step(&data, expected, ret)) {
            goto exit;
        }
#if defined(MBEDTLS_ASN1_PARSE_C)
        if (ret >= 0) {
            TEST_EQUAL(mbedtls_asn1_get_mpi(&data.p, data.end, &read), 0);
            TEST_EQUAL(0, mbedtls_mpi_cmp_mpi(&mpi, &read));
        }
#endif /* MBEDTLS_ASN1_PARSE_C */
        /* Skip some intermediate lengths, they're boring. */
        if (expected->len > 10 && data.size == 8) {
            data.size = expected->len - 2;
        }
    }

exit:
    mbedtls_mpi_free(&mpi);
    mbedtls_mpi_free(&read);
    mbedtls_free(data.output);
}
/* END_CASE */

/* BEGIN_CASE */
void mbedtls_asn1_write_string(int tag, data_t *content, data_t *expected)
{
    generic_write_data_t data = { NULL, NULL, NULL, NULL, 0 };
    int ret;

    for (data.size = 0; data.size <= expected->len + 1; data.size++) {
        if (!generic_write_start_step(&data)) {
            goto exit;
        }
        switch (tag) {
            case MBEDTLS_ASN1_OCTET_STRING:
                ret = mbedtls_asn1_write_octet_string(
                    &data.p, data.start, content->x, content->len);
                break;
            case MBEDTLS_ASN1_OID:
                ret = mbedtls_asn1_write_oid(
                    &data.p, data.start,
                    (const char *) content->x, content->len);
                break;
            case MBEDTLS_ASN1_UTF8_STRING:
                ret = mbedtls_asn1_write_utf8_string(
                    &data.p, data.start,
                    (const char *) content->x, content->len);
                break;
            case MBEDTLS_ASN1_PRINTABLE_STRING:
                ret = mbedtls_asn1_write_printable_string(
                    &data.p, data.start,
                    (const char *) content->x, content->len);
                break;
            case MBEDTLS_ASN1_IA5_STRING:
                ret = mbedtls_asn1_write_ia5_string(
                    &data.p, data.start,
                    (const char *) content->x, content->len);
                break;
            default:
                ret = mbedtls_asn1_write_tagged_string(
                    &data.p, data.start, tag,
                    (const char *) content->x, content->len);
        }
        if (!generic_write_finish_step(&data, expected, ret)) {
            goto exit;
        }
        /* There's no parsing function for octet or character strings. */
        /* Skip some intermediate lengths, they're boring. */
        if (expected->len > 10 && data.size == 8) {
            data.size = expected->len - 2;
        }
    }

exit:
    mbedtls_free(data.output);
}
/* END_CASE */

/* BEGIN_CASE */
void mbedtls_asn1_write_algorithm_identifier(data_t *oid,
                                             int par_len,
                                             data_t *expected)
{
    generic_write_data_t data = { NULL, NULL, NULL, NULL, 0 };
    int ret;
#if defined(MBEDTLS_ASN1_PARSE_C)
    unsigned char *buf_complete = NULL;
#endif /* MBEDTLS_ASN1_PARSE_C */

    for (data.size = 0; data.size <= expected->len + 1; data.size++) {
        if (!generic_write_start_step(&data)) {
            goto exit;
        }
        ret = mbedtls_asn1_write_algorithm_identifier(
            &data.p, data.start,
            (const char *) oid->x, oid->len, par_len);
        /* If params_len != 0, mbedtls_asn1_write_algorithm_identifier()
         * assumes that the parameters are already present in the buffer
         * and returns a length that accounts for this, but our test
         * data omits the parameters. */
        if (ret >= 0) {
            ret -= par_len;
        }
        if (!generic_write_finish_step(&data, expected, ret)) {
            goto exit;
        }

#if defined(MBEDTLS_ASN1_PARSE_C)
        /* Only do a parse-back test if the parameters aren't too large for
         * a small-heap environment. The boundary is somewhat arbitrary. */
        if (ret >= 0 && par_len <= 1234) {
            mbedtls_asn1_buf alg = { 0, 0, NULL };
            mbedtls_asn1_buf params = { 0, 0, NULL };
            /* The writing function doesn't write the parameters unless
             * they're null: it only takes their length as input. But the
             * parsing function requires the parameters to be present.
             * Thus make up parameters. */
            size_t data_len = data.end - data.p;
            size_t len_complete = data_len + par_len;
            unsigned char expected_params_tag;
            size_t expected_params_len;
            ASSERT_ALLOC(buf_complete, len_complete);
            unsigned char *end_complete = buf_complete + len_complete;
            memcpy(buf_complete, data.p, data_len);
            if (par_len == 0) {
                /* mbedtls_asn1_write_algorithm_identifier() wrote a NULL */
                expected_params_tag = 0x05;
                expected_params_len = 0;
            } else if (par_len >= 2 && par_len < 2 + 128) {
                /* Write an OCTET STRING with a short length encoding */
                expected_params_tag = buf_complete[data_len] = 0x04;
                expected_params_len = par_len - 2;
                buf_complete[data_len + 1] = (unsigned char) expected_params_len;
            } else if (par_len >= 4 + 128 && par_len < 3 + 256 * 256) {
                /* Write an OCTET STRING with a two-byte length encoding */
                expected_params_tag = buf_complete[data_len] = 0x04;
                expected_params_len = par_len - 4;
                buf_complete[data_len + 1] = 0x82;
                buf_complete[data_len + 2] = (unsigned char) (expected_params_len >> 8);
                buf_complete[data_len + 3] = (unsigned char) (expected_params_len);
            } else {
                TEST_ASSERT(!"Bad test data: invalid length of ASN.1 element");
            }
            unsigned char *p = buf_complete;
            TEST_EQUAL(mbedtls_asn1_get_alg(&p, end_complete,
                                            &alg, &params), 0);
            TEST_EQUAL(alg.tag, MBEDTLS_ASN1_OID);
            ASSERT_COMPARE(alg.p, alg.len, oid->x, oid->len);
            TEST_EQUAL(params.tag, expected_params_tag);
            TEST_EQUAL(params.len, expected_params_len);
            mbedtls_free(buf_complete);
            buf_complete = NULL;
        }
#endif /* MBEDTLS_ASN1_PARSE_C */
    }

exit:
    mbedtls_free(data.output);
#if defined(MBEDTLS_ASN1_PARSE_C)
    mbedtls_free(buf_complete);
#endif /* MBEDTLS_ASN1_PARSE_C */
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_ASN1_PARSE_C */
void mbedtls_asn1_write_len(int len, data_t *asn1, int buf_len,
                            int result)
{
    int ret;
    unsigned char buf[150];
    unsigned char *p;
    size_t i;
    size_t read_len;

    memset(buf, GUARD_VAL, sizeof(buf));

    p = buf + GUARD_LEN + buf_len;

    ret = mbedtls_asn1_write_len(&p, buf + GUARD_LEN, (size_t) len);

    TEST_ASSERT(ret == result);

    /* Check for buffer overwrite on both sides */
    for (i = 0; i < GUARD_LEN; i++) {
        TEST_ASSERT(buf[i] == GUARD_VAL);
        TEST_ASSERT(buf[GUARD_LEN + buf_len + i] == GUARD_VAL);
    }

    if (result >= 0) {
        TEST_ASSERT(p + asn1->len == buf + GUARD_LEN + buf_len);

        TEST_ASSERT(memcmp(p, asn1->x, asn1->len) == 0);

        /* Read back with mbedtls_asn1_get_len() to check */
        ret = mbedtls_asn1_get_len(&p, buf + GUARD_LEN + buf_len, &read_len);

        if (len == 0) {
            TEST_ASSERT(ret == 0);
        } else {
            /* Return will be MBEDTLS_ERR_ASN1_OUT_OF_DATA because the rest of
             * the buffer is missing
             */
            TEST_ASSERT(ret == MBEDTLS_ERR_ASN1_OUT_OF_DATA);
        }
        TEST_ASSERT(read_len == (size_t) len);
        TEST_ASSERT(p == buf + GUARD_LEN + buf_len);
    }
}
/* END_CASE */

/* BEGIN_CASE */
void test_asn1_write_bitstrings(data_t *bitstring, int bits,
                                data_t *expected, int is_named)
{
    generic_write_data_t data = { NULL, NULL, NULL, NULL, 0 };
    int ret;
    int (*func)(unsigned char **p, const unsigned char *start,
                const unsigned char *buf, size_t bits) =
        (is_named ? mbedtls_asn1_write_named_bitstring :
         mbedtls_asn1_write_bitstring);
#if defined(MBEDTLS_ASN1_PARSE_C)
    unsigned char *masked_bitstring = NULL;
#endif /* MBEDTLS_ASN1_PARSE_C */

    /* The API expects `bitstring->x` to contain `bits` bits. */
    size_t byte_length = (bits + 7) / 8;
    TEST_ASSERT(bitstring->len >= byte_length);

#if defined(MBEDTLS_ASN1_PARSE_C)
    ASSERT_ALLOC(masked_bitstring, byte_length);
    if (byte_length != 0) {
        memcpy(masked_bitstring, bitstring->x, byte_length);
        if (bits % 8 != 0) {
            masked_bitstring[byte_length - 1] &= ~(0xff >> (bits % 8));
        }
    }
    size_t value_bits = bits;
    if (is_named) {
        /* In a named bit string, all trailing 0 bits are removed. */
        while (byte_length > 0 && masked_bitstring[byte_length - 1] == 0) {
            --byte_length;
        }
        value_bits = 8 * byte_length;
        if (byte_length > 0) {
            unsigned char last_byte = masked_bitstring[byte_length - 1];
            for (unsigned b = 1; b < 0xff && (last_byte & b) == 0; b <<= 1) {
                --value_bits;
            }
        }
    }
#endif /* MBEDTLS_ASN1_PARSE_C */

    for (data.size = 0; data.size <= expected->len + 1; data.size++) {
        if (!generic_write_start_step(&data)) {
            goto exit;
        }
        ret = (*func)(&data.p, data.start, bitstring->x, bits);
        if (!generic_write_finish_step(&data, expected, ret)) {
            goto exit;
        }
#if defined(MBEDTLS_ASN1_PARSE_C)
        if (ret >= 0) {
            mbedtls_asn1_bitstring read = { 0, 0, NULL };
            TEST_EQUAL(mbedtls_asn1_get_bitstring(&data.p, data.end,
                                                  &read), 0);
            ASSERT_COMPARE(read.p, read.len,
                           masked_bitstring, byte_length);
            TEST_EQUAL(read.unused_bits, 8 * byte_length - value_bits);
        }
#endif /* MBEDTLS_ASN1_PARSE_C */
    }

exit:
    mbedtls_free(data.output);
#if defined(MBEDTLS_ASN1_PARSE_C)
    mbedtls_free(masked_bitstring);
#endif /* MBEDTLS_ASN1_PARSE_C */
}
/* END_CASE */

/* BEGIN_CASE */
void store_named_data_find(data_t *oid0, data_t *oid1,
                           data_t *oid2, data_t *oid3,
                           data_t *needle, int from, int position)
{
    data_t *oid[4] = { oid0, oid1, oid2, oid3 };
    mbedtls_asn1_named_data nd[] = {
        { { 0x06, 0, NULL }, { 0, 0, NULL }, NULL, 0 },
        { { 0x06, 0, NULL }, { 0, 0, NULL }, NULL, 0 },
        { { 0x06, 0, NULL }, { 0, 0, NULL }, NULL, 0 },
        { { 0x06, 0, NULL }, { 0, 0, NULL }, NULL, 0 },
    };
    mbedtls_asn1_named_data *pointers[ARRAY_LENGTH(nd) + 1];
    size_t i;
    mbedtls_asn1_named_data *head = NULL;
    mbedtls_asn1_named_data *found = NULL;

    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++) {
        ASSERT_ALLOC(nd[i].oid.p, oid[i]->len);
        memcpy(nd[i].oid.p, oid[i]->x, oid[i]->len);
        nd[i].oid.len = oid[i]->len;
        nd[i].next = pointers[i+1];
    }

    head = pointers[from];
    found = mbedtls_asn1_store_named_data(&head,
                                          (const char *) needle->x,
                                          needle->len,
                                          NULL, 0);

    /* In any case, the existing list structure must be unchanged. */
    for (i = 0; i < ARRAY_LENGTH(nd); i++) {
        TEST_ASSERT(nd[i].next == pointers[i+1]);
    }

    if (position >= 0) {
        /* position should have been found and modified. */
        TEST_ASSERT(head == pointers[from]);
        TEST_ASSERT(found == pointers[position]);
    } else {
        /* A new entry should have been created. */
        TEST_ASSERT(found == head);
        TEST_ASSERT(head->next == pointers[from]);
        for (i = 0; i < ARRAY_LENGTH(nd); i++) {
            TEST_ASSERT(found != &nd[i]);
        }
    }

exit:
    if (found != NULL && found == head && found != pointers[from]) {
        mbedtls_free(found->oid.p);
        mbedtls_free(found);
    }
    for (i = 0; i < ARRAY_LENGTH(nd); i++) {
        mbedtls_free(nd[i].oid.p);
    }
}
/* END_CASE */

/* BEGIN_CASE */
void store_named_data_val_found(int old_len, int new_len)
{
    mbedtls_asn1_named_data nd =
    { { 0x06, 3, (unsigned char *) "OID" }, { 0, 0, NULL }, NULL, 0 };
    mbedtls_asn1_named_data *head = &nd;
    mbedtls_asn1_named_data *found = NULL;
    unsigned char *old_val = NULL;
    unsigned char *new_val = (unsigned char *) "new value";

    if (old_len != 0) {
        ASSERT_ALLOC(nd.val.p, (size_t) old_len);
        old_val = nd.val.p;
        nd.val.len = old_len;
        memset(old_val, 'x', old_len);
    }
    if (new_len <= 0) {
        new_len = -new_len;
        new_val = NULL;
    }

    found = mbedtls_asn1_store_named_data(&head, "OID", 3,
                                          new_val, new_len);
    TEST_ASSERT(head == &nd);
    TEST_ASSERT(found == head);

    if (new_val != NULL) {
        ASSERT_COMPARE(found->val.p, found->val.len,
                       new_val, (size_t) new_len);
    }
    if (new_len == 0) {
        TEST_ASSERT(found->val.p == NULL);
    } else if (new_len == old_len) {
        TEST_ASSERT(found->val.p == old_val);
    } else {
        TEST_ASSERT(found->val.p != old_val);
    }

exit:
    mbedtls_free(nd.val.p);
}
/* END_CASE */

/* BEGIN_CASE */
void store_named_data_val_new(int new_len, int set_new_val)
{
    mbedtls_asn1_named_data *head = NULL;
    mbedtls_asn1_named_data *found = NULL;
    const unsigned char *oid = (unsigned char *) "OID";
    size_t oid_len = strlen((const char *) oid);
    const unsigned char *new_val = (unsigned char *) "new value";

    if (set_new_val == 0) {
        new_val = NULL;
    }

    found = mbedtls_asn1_store_named_data(&head,
                                          (const char *) oid, oid_len,
                                          new_val, (size_t) new_len);
    TEST_ASSERT(found != NULL);
    TEST_ASSERT(found == head);
    TEST_ASSERT(found->oid.p != oid);
    ASSERT_COMPARE(found->oid.p, found->oid.len, oid, oid_len);
    if (new_len == 0) {
        TEST_ASSERT(found->val.p == NULL);
    } else if (new_val == NULL) {
        TEST_ASSERT(found->val.p != NULL);
    } else {
        TEST_ASSERT(found->val.p != new_val);
        ASSERT_COMPARE(found->val.p, found->val.len,
                       new_val, (size_t) new_len);
    }

exit:
    if (found != NULL) {
        mbedtls_free(found->oid.p);
        mbedtls_free(found->val.p);
    }
    mbedtls_free(found);
}
/* END_CASE */