/src/mbedtls/library/ccm.c

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/*
 *  NIST SP800-38C compliant CCM implementation
 *
 *  Copyright The Mbed TLS Contributors
 *  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.
 */

/*
 * Definition of CCM:
 * http://csrc.nist.gov/publications/nistpubs/800-38C/SP800-38C_updated-July20_2007.pdf
 * RFC 3610 "Counter with CBC-MAC (CCM)"
 *
 * Related:
 * RFC 5116 "An Interface and Algorithms for Authenticated Encryption"
 */

#include "common.h"

#if defined(MBEDTLS_CCM_C)

#include "mbedtls/ccm.h"
#include "mbedtls/platform_util.h"
#include "mbedtls/error.h"

#include <string.h>

#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
#else
#if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C)
#include <stdio.h>
#define mbedtls_printf printf
#endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */
#endif /* MBEDTLS_PLATFORM_C */

#if !defined(MBEDTLS_CCM_ALT)


/*
 * Initialize context
 */
void mbedtls_ccm_init(mbedtls_ccm_context *ctx)
{
    memset(ctx, 0, sizeof(mbedtls_ccm_context));
}

int mbedtls_ccm_setkey(mbedtls_ccm_context *ctx,
                       mbedtls_cipher_id_t cipher,
                       const unsigned char *key,
                       unsigned int keybits)
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    const mbedtls_cipher_info_t *cipher_info;

    cipher_info = mbedtls_cipher_info_from_values(cipher, keybits,
                                                  MBEDTLS_MODE_ECB);
    if (cipher_info == NULL) {
        return MBEDTLS_ERR_CCM_BAD_INPUT;
    }

    if (cipher_info->block_size != 16) {
        return MBEDTLS_ERR_CCM_BAD_INPUT;
    }

    mbedtls_cipher_free(&ctx->cipher_ctx);

    if ((ret = mbedtls_cipher_setup(&ctx->cipher_ctx, cipher_info)) != 0) {
        return ret;
    }

    if ((ret = mbedtls_cipher_setkey(&ctx->cipher_ctx, key, keybits,
                                     MBEDTLS_ENCRYPT)) != 0) {
        return ret;
    }

    return 0;
}

/*
 * Free context
 */
void mbedtls_ccm_free(mbedtls_ccm_context *ctx)
{
    if (ctx == NULL) {
        return;
    }
    mbedtls_cipher_free(&ctx->cipher_ctx);
    mbedtls_platform_zeroize(ctx, sizeof(mbedtls_ccm_context));
}

#define CCM_STATE__CLEAR                0
#define CCM_STATE__STARTED              (1 << 0)
#define CCM_STATE__LENGTHS_SET          (1 << 1)
#define CCM_STATE__AUTH_DATA_STARTED    (1 << 2)
#define CCM_STATE__AUTH_DATA_FINISHED   (1 << 3)
#define CCM_STATE__ERROR                (1 << 4)

/*
 * Encrypt or decrypt a partial block with CTR
 */
static int mbedtls_ccm_crypt(mbedtls_ccm_context *ctx,
                             size_t offset, size_t use_len,
                             const unsigned char *input,
                             unsigned char *output)
{
    size_t olen = 0;
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    unsigned char tmp_buf[16] = { 0 };

    if ((ret = mbedtls_cipher_update(&ctx->cipher_ctx, ctx->ctr, 16, tmp_buf,
                                     &olen)) != 0) {
        ctx->state |= CCM_STATE__ERROR;
        mbedtls_platform_zeroize(tmp_buf, sizeof(tmp_buf));
        return ret;
    }

    mbedtls_xor(output, input, tmp_buf + offset, use_len);

    mbedtls_platform_zeroize(tmp_buf, sizeof(tmp_buf));
    return ret;
}

static void mbedtls_ccm_clear_state(mbedtls_ccm_context *ctx)
{
    ctx->state = CCM_STATE__CLEAR;
    memset(ctx->y, 0, 16);
    memset(ctx->ctr, 0, 16);
}

static int ccm_calculate_first_block_if_ready(mbedtls_ccm_context *ctx)
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    unsigned char i;
    size_t len_left, olen;

    /* length calculation can be done only after both
     * mbedtls_ccm_starts() and mbedtls_ccm_set_lengths() have been executed
     */
    if (!(ctx->state & CCM_STATE__STARTED) || !(ctx->state & CCM_STATE__LENGTHS_SET)) {
        return 0;
    }

    /* CCM expects non-empty tag.
     * CCM* allows empty tag. For CCM* without tag, ignore plaintext length.
     */
    if (ctx->tag_len == 0) {
        if (ctx->mode == MBEDTLS_CCM_STAR_ENCRYPT || ctx->mode == MBEDTLS_CCM_STAR_DECRYPT) {
            ctx->plaintext_len = 0;
        } else {
            return MBEDTLS_ERR_CCM_BAD_INPUT;
        }
    }

    /*
     * First block:
     * 0        .. 0        flags
     * 1        .. iv_len   nonce (aka iv)  - set by: mbedtls_ccm_starts()
     * iv_len+1 .. 15       length
     *
     * With flags as (bits):
     * 7        0
     * 6        add present?
     * 5 .. 3   (t - 2) / 2
     * 2 .. 0   q - 1
     */
    ctx->y[0] |= (ctx->add_len > 0) << 6;
    ctx->y[0] |= ((ctx->tag_len - 2) / 2) << 3;
    ctx->y[0] |= ctx->q - 1;

    for (i = 0, len_left = ctx->plaintext_len; i < ctx->q; i++, len_left >>= 8) {
        ctx->y[15-i] = MBEDTLS_BYTE_0(len_left);
    }

    if (len_left > 0) {
        ctx->state |= CCM_STATE__ERROR;
        return MBEDTLS_ERR_CCM_BAD_INPUT;
    }

    /* Start CBC-MAC with first block*/
    if ((ret = mbedtls_cipher_update(&ctx->cipher_ctx, ctx->y, 16, ctx->y, &olen)) != 0) {
        ctx->state |= CCM_STATE__ERROR;
        return ret;
    }

    return 0;
}

int mbedtls_ccm_starts(mbedtls_ccm_context *ctx,
                       int mode,
                       const unsigned char *iv,
                       size_t iv_len)
{
    /* Also implies q is within bounds */
    if (iv_len < 7 || iv_len > 13) {
        return MBEDTLS_ERR_CCM_BAD_INPUT;
    }

    ctx->mode = mode;
    ctx->q = 16 - 1 - (unsigned char) iv_len;

    /*
     * Prepare counter block for encryption:
     * 0        .. 0        flags
     * 1        .. iv_len   nonce (aka iv)
     * iv_len+1 .. 15       counter (initially 1)
     *
     * With flags as (bits):
     * 7 .. 3   0
     * 2 .. 0   q - 1
     */
    memset(ctx->ctr, 0, 16);
    ctx->ctr[0] = ctx->q - 1;
    memcpy(ctx->ctr + 1, iv, iv_len);
    memset(ctx->ctr + 1 + iv_len, 0, ctx->q);
    ctx->ctr[15] = 1;

    /*
     * See ccm_calculate_first_block_if_ready() for block layout description
     */
    memcpy(ctx->y + 1, iv, iv_len);

    ctx->state |= CCM_STATE__STARTED;
    return ccm_calculate_first_block_if_ready(ctx);
}

int mbedtls_ccm_set_lengths(mbedtls_ccm_context *ctx,
                            size_t total_ad_len,
                            size_t plaintext_len,
                            size_t tag_len)
{
    /*
     * Check length requirements: SP800-38C A.1
     * Additional requirement: a < 2^16 - 2^8 to simplify the code.
     * 'length' checked later (when writing it to the first block)
     *
     * Also, loosen the requirements to enable support for CCM* (IEEE 802.15.4).
     */
    if (tag_len == 2 || tag_len > 16 || tag_len % 2 != 0) {
        return MBEDTLS_ERR_CCM_BAD_INPUT;
    }

    if (total_ad_len >= 0xFF00) {
        return MBEDTLS_ERR_CCM_BAD_INPUT;
    }

    ctx->plaintext_len = plaintext_len;
    ctx->add_len = total_ad_len;
    ctx->tag_len = tag_len;
    ctx->processed = 0;

    ctx->state |= CCM_STATE__LENGTHS_SET;
    return ccm_calculate_first_block_if_ready(ctx);
}

int mbedtls_ccm_update_ad(mbedtls_ccm_context *ctx,
                          const unsigned char *add,
                          size_t add_len)
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    size_t olen, use_len, offset;

    if (ctx->state & CCM_STATE__ERROR) {
        return MBEDTLS_ERR_CCM_BAD_INPUT;
    }

    if (add_len > 0) {
        if (ctx->state & CCM_STATE__AUTH_DATA_FINISHED) {
            return MBEDTLS_ERR_CCM_BAD_INPUT;
        }

        if (!(ctx->state & CCM_STATE__AUTH_DATA_STARTED)) {
            if (add_len > ctx->add_len) {
                return MBEDTLS_ERR_CCM_BAD_INPUT;
            }

            ctx->y[0] ^= (unsigned char) ((ctx->add_len >> 8) & 0xFF);
            ctx->y[1] ^= (unsigned char) ((ctx->add_len) & 0xFF);

            ctx->state |= CCM_STATE__AUTH_DATA_STARTED;
        } else if (ctx->processed + add_len > ctx->add_len) {
            return MBEDTLS_ERR_CCM_BAD_INPUT;
        }

        while (add_len > 0) {
            offset = (ctx->processed + 2) % 16; /* account for y[0] and y[1]
                                                 * holding total auth data length */
            use_len = 16 - offset;

            if (use_len > add_len) {
                use_len = add_len;
            }

            mbedtls_xor(ctx->y + offset, ctx->y + offset, add, use_len);

            ctx->processed += use_len;
            add_len -= use_len;
            add += use_len;

            if (use_len + offset == 16 || ctx->processed == ctx->add_len) {
                if ((ret =
                         mbedtls_cipher_update(&ctx->cipher_ctx, ctx->y, 16, ctx->y, &olen)) != 0) {
                    ctx->state |= CCM_STATE__ERROR;
                    return ret;
                }
            }
        }

        if (ctx->processed == ctx->add_len) {
            ctx->state |= CCM_STATE__AUTH_DATA_FINISHED;
            ctx->processed = 0; // prepare for mbedtls_ccm_update()
        }
    }

    return 0;
}

int mbedtls_ccm_update(mbedtls_ccm_context *ctx,
                       const unsigned char *input, size_t input_len,
                       unsigned char *output, size_t output_size,
                       size_t *output_len)
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    unsigned char i;
    size_t use_len, offset, olen;

    unsigned char local_output[16];

    if (ctx->state & CCM_STATE__ERROR) {
        return MBEDTLS_ERR_CCM_BAD_INPUT;
    }

    /* Check against plaintext length only if performing operation with
     * authentication
     */
    if (ctx->tag_len != 0 && ctx->processed + input_len > ctx->plaintext_len) {
        return MBEDTLS_ERR_CCM_BAD_INPUT;
    }

    if (output_size < input_len) {
        return MBEDTLS_ERR_CCM_BAD_INPUT;
    }
    *output_len = input_len;

    ret = 0;

    while (input_len > 0) {
        offset = ctx->processed % 16;

        use_len = 16 - offset;

        if (use_len > input_len) {
            use_len = input_len;
        }

        ctx->processed += use_len;

        if (ctx->mode == MBEDTLS_CCM_ENCRYPT || \
            ctx->mode == MBEDTLS_CCM_STAR_ENCRYPT) {
            mbedtls_xor(ctx->y + offset, ctx->y + offset, input, use_len);

            if (use_len + offset == 16 || ctx->processed == ctx->plaintext_len) {
                if ((ret =
                         mbedtls_cipher_update(&ctx->cipher_ctx, ctx->y, 16, ctx->y, &olen)) != 0) {
                    ctx->state |= CCM_STATE__ERROR;
                    goto exit;
                }
            }

            ret = mbedtls_ccm_crypt(ctx, offset, use_len, input, output);
            if (ret != 0) {
                goto exit;
            }
        }

        if (ctx->mode == MBEDTLS_CCM_DECRYPT || \
            ctx->mode == MBEDTLS_CCM_STAR_DECRYPT) {
            /* Since output may be in shared memory, we cannot be sure that
             * it will contain what we wrote to it. Therefore, we should avoid using
             * it as input to any operations.
             * Write decrypted data to local_output to avoid using output variable as
             * input in the XOR operation for Y.
             */
            ret = mbedtls_ccm_crypt(ctx, offset, use_len, input, local_output);
            if (ret != 0) {
                goto exit;
            }

            mbedtls_xor(ctx->y + offset, ctx->y + offset, local_output, use_len);

            memcpy(output, local_output, use_len);
            mbedtls_platform_zeroize(local_output, 16);

            if (use_len + offset == 16 || ctx->processed == ctx->plaintext_len) {
                if ((ret =
                         mbedtls_cipher_update(&ctx->cipher_ctx, ctx->y, 16, ctx->y, &olen)) != 0) {
                    ctx->state |= CCM_STATE__ERROR;
                    goto exit;
                }
            }
        }

        if (use_len + offset == 16 || ctx->processed == ctx->plaintext_len) {
            for (i = 0; i < ctx->q; i++) {
                if (++(ctx->ctr)[15-i] != 0) {
                    break;
                }
            }
        }

        input_len -= use_len;
        input += use_len;
        output += use_len;
    }

exit:
    mbedtls_platform_zeroize(local_output, 16);

    return ret;
}

int mbedtls_ccm_finish(mbedtls_ccm_context *ctx,
                       unsigned char *tag, size_t tag_len)
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    unsigned char i;

    if (ctx->state & CCM_STATE__ERROR) {
        return MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    }

    if (ctx->add_len > 0 && !(ctx->state & CCM_STATE__AUTH_DATA_FINISHED)) {
        return MBEDTLS_ERR_CCM_BAD_INPUT;
    }

    if (ctx->plaintext_len > 0 && ctx->processed != ctx->plaintext_len) {
        return MBEDTLS_ERR_CCM_BAD_INPUT;
    }

    /*
     * Authentication: reset counter and crypt/mask internal tag
     */
    for (i = 0; i < ctx->q; i++) {
        ctx->ctr[15-i] = 0;
    }

    ret = mbedtls_ccm_crypt(ctx, 0, 16, ctx->y, ctx->y);
    if (ret != 0) {
        return ret;
    }
    if (tag != NULL) {
        memcpy(tag, ctx->y, tag_len);
    }
    mbedtls_ccm_clear_state(ctx);

    return 0;
}

/*
 * Authenticated encryption or decryption
 */
static int ccm_auth_crypt(mbedtls_ccm_context *ctx, int mode, size_t length,
                          const unsigned char *iv, size_t iv_len,
                          const unsigned char *add, size_t add_len,
                          const unsigned char *input, unsigned char *output,
                          unsigned char *tag, size_t tag_len)
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    size_t olen;

    if ((ret = mbedtls_ccm_starts(ctx, mode, iv, iv_len)) != 0) {
        return ret;
    }

    if ((ret = mbedtls_ccm_set_lengths(ctx, add_len, length, tag_len)) != 0) {
        return ret;
    }

    if ((ret = mbedtls_ccm_update_ad(ctx, add, add_len)) != 0) {
        return ret;
    }

    if ((ret = mbedtls_ccm_update(ctx, input, length,
                                  output, length, &olen)) != 0) {
        return ret;
    }

    if ((ret = mbedtls_ccm_finish(ctx, tag, tag_len)) != 0) {
        return ret;
    }

    return 0;
}

/*
 * Authenticated encryption
 */
int mbedtls_ccm_star_encrypt_and_tag(mbedtls_ccm_context *ctx, size_t length,
                                     const unsigned char *iv, size_t iv_len,
                                     const unsigned char *add, size_t add_len,
                                     const unsigned char *input, unsigned char *output,
                                     unsigned char *tag, size_t tag_len)
{
    return ccm_auth_crypt(ctx, MBEDTLS_CCM_STAR_ENCRYPT, length, iv, iv_len,
                          add, add_len, input, output, tag, tag_len);
}

int mbedtls_ccm_encrypt_and_tag(mbedtls_ccm_context *ctx, size_t length,
                                const unsigned char *iv, size_t iv_len,
                                const unsigned char *add, size_t add_len,
                                const unsigned char *input, unsigned char *output,
                                unsigned char *tag, size_t tag_len)
{
    return ccm_auth_crypt(ctx, MBEDTLS_CCM_ENCRYPT, length, iv, iv_len,
                          add, add_len, input, output, tag, tag_len);
}

/*
 * Authenticated decryption
 */
static int mbedtls_ccm_compare_tags(const unsigned char *tag1,
                                    const unsigned char *tag2,
                                    size_t tag_len)
{
    unsigned char i;
    int diff;

    /* Check tag in "constant-time" */
    for (diff = 0, i = 0; i < tag_len; i++) {
        diff |= tag1[i] ^ tag2[i];
    }

    if (diff != 0) {
        return MBEDTLS_ERR_CCM_AUTH_FAILED;
    }

    return 0;
}

static int ccm_auth_decrypt(mbedtls_ccm_context *ctx, int mode, size_t length,
                            const unsigned char *iv, size_t iv_len,
                            const unsigned char *add, size_t add_len,
                            const unsigned char *input, unsigned char *output,
                            const unsigned char *tag, size_t tag_len)
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    unsigned char check_tag[16];

    if ((ret = ccm_auth_crypt(ctx, mode, length,
                              iv, iv_len, add, add_len,
                              input, output, check_tag, tag_len)) != 0) {
        return ret;
    }

    if ((ret = mbedtls_ccm_compare_tags(tag, check_tag, tag_len)) != 0) {
        mbedtls_platform_zeroize(output, length);
        return ret;
    }

    return 0;
}

int mbedtls_ccm_star_auth_decrypt(mbedtls_ccm_context *ctx, size_t length,
                                  const unsigned char *iv, size_t iv_len,
                                  const unsigned char *add, size_t add_len,
                                  const unsigned char *input, unsigned char *output,
                                  const unsigned char *tag, size_t tag_len)
{
    return ccm_auth_decrypt(ctx, MBEDTLS_CCM_STAR_DECRYPT, length,
                            iv, iv_len, add, add_len,
                            input, output, tag, tag_len);
}

int mbedtls_ccm_auth_decrypt(mbedtls_ccm_context *ctx, size_t length,
                             const unsigned char *iv, size_t iv_len,
                             const unsigned char *add, size_t add_len,
                             const unsigned char *input, unsigned char *output,
                             const unsigned char *tag, size_t tag_len)
{
    return ccm_auth_decrypt(ctx, MBEDTLS_CCM_DECRYPT, length,
                            iv, iv_len, add, add_len,
                            input, output, tag, tag_len);
}
#endif /* !MBEDTLS_CCM_ALT */

#if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C)
/*
 * Examples 1 to 3 from SP800-38C Appendix C
 */

#define NB_TESTS 3
#define CCM_SELFTEST_PT_MAX_LEN 24
#define CCM_SELFTEST_CT_MAX_LEN 32
/*
 * The data is the same for all tests, only the used length changes
 */
static const unsigned char key_test_data[] = {
    0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
    0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f
};

static const unsigned char iv_test_data[] = {
    0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
    0x18, 0x19, 0x1a, 0x1b
};

static const unsigned char ad_test_data[] = {
    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
    0x10, 0x11, 0x12, 0x13
};

static const unsigned char msg_test_data[CCM_SELFTEST_PT_MAX_LEN] = {
    0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
    0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
    0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
};

static const size_t iv_len_test_data[NB_TESTS] = { 7, 8,  12 };
static const size_t add_len_test_data[NB_TESTS] = { 8, 16, 20 };
static const size_t msg_len_test_data[NB_TESTS] = { 4, 16, 24 };
static const size_t tag_len_test_data[NB_TESTS] = { 4, 6,  8  };

static const unsigned char res_test_data[NB_TESTS][CCM_SELFTEST_CT_MAX_LEN] = {
    {   0x71, 0x62, 0x01, 0x5b, 0x4d, 0xac, 0x25, 0x5d },
    {   0xd2, 0xa1, 0xf0, 0xe0, 0x51, 0xea, 0x5f, 0x62,
        0x08, 0x1a, 0x77, 0x92, 0x07, 0x3d, 0x59, 0x3d,
        0x1f, 0xc6, 0x4f, 0xbf, 0xac, 0xcd },
    {   0xe3, 0xb2, 0x01, 0xa9, 0xf5, 0xb7, 0x1a, 0x7a,
        0x9b, 0x1c, 0xea, 0xec, 0xcd, 0x97, 0xe7, 0x0b,
        0x61, 0x76, 0xaa, 0xd9, 0xa4, 0x42, 0x8a, 0xa5,
        0x48, 0x43, 0x92, 0xfb, 0xc1, 0xb0, 0x99, 0x51 }
};

int mbedtls_ccm_self_test(int verbose)
{
    mbedtls_ccm_context ctx;
    /*
     * Some hardware accelerators require the input and output buffers
     * would be in RAM, because the flash is not accessible.
     * Use buffers on the stack to hold the test vectors data.
     */
    unsigned char plaintext[CCM_SELFTEST_PT_MAX_LEN];
    unsigned char ciphertext[CCM_SELFTEST_CT_MAX_LEN];
    size_t i;
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;

    mbedtls_ccm_init(&ctx);

    if (mbedtls_ccm_setkey(&ctx, MBEDTLS_CIPHER_ID_AES, key_test_data,
                           8 * sizeof key_test_data) != 0) {
        if (verbose != 0) {
            mbedtls_printf("  CCM: setup failed");
        }

        return 1;
    }

    for (i = 0; i < NB_TESTS; i++) {
        if (verbose != 0) {
            mbedtls_printf("  CCM-AES #%u: ", (unsigned int) i + 1);
        }

        memset(plaintext, 0, CCM_SELFTEST_PT_MAX_LEN);
        memset(ciphertext, 0, CCM_SELFTEST_CT_MAX_LEN);
        memcpy(plaintext, msg_test_data, msg_len_test_data[i]);

        ret = mbedtls_ccm_encrypt_and_tag(&ctx, msg_len_test_data[i],
                                          iv_test_data, iv_len_test_data[i],
                                          ad_test_data, add_len_test_data[i],
                                          plaintext, ciphertext,
                                          ciphertext + msg_len_test_data[i],
                                          tag_len_test_data[i]);

        if (ret != 0 ||
            memcmp(ciphertext, res_test_data[i],
                   msg_len_test_data[i] + tag_len_test_data[i]) != 0) {
            if (verbose != 0) {
                mbedtls_printf("failed\n");
            }

            return 1;
        }
        memset(plaintext, 0, CCM_SELFTEST_PT_MAX_LEN);

        ret = mbedtls_ccm_auth_decrypt(&ctx, msg_len_test_data[i],
                                       iv_test_data, iv_len_test_data[i],
                                       ad_test_data, add_len_test_data[i],
                                       ciphertext, plaintext,
                                       ciphertext + msg_len_test_data[i],
                                       tag_len_test_data[i]);

        if (ret != 0 ||
            memcmp(plaintext, msg_test_data, msg_len_test_data[i]) != 0) {
            if (verbose != 0) {
                mbedtls_printf("failed\n");
            }

            return 1;
        }

        if (verbose != 0) {
            mbedtls_printf("passed\n");
        }
    }

    mbedtls_ccm_free(&ctx);

    if (verbose != 0) {
        mbedtls_printf("\n");
    }

    return 0;
}

#endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */

#endif /* MBEDTLS_CCM_C */

Coverage Report

Created: 2024-08-27 12:19

Line	Count	Source (jump to first uncovered line)
1		/*
2		* NIST SP800-38C compliant CCM implementation
3		*
4		* Copyright The Mbed TLS Contributors
5		* SPDX-License-Identifier: Apache-2.0
6		*
7		* Licensed under the Apache License, Version 2.0 (the "License"); you may
8		* not use this file except in compliance with the License.
9		* You may obtain a copy of the License at
10		*
11		* http://www.apache.org/licenses/LICENSE-2.0
12		*
13		* Unless required by applicable law or agreed to in writing, software
14		* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
15		* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16		* See the License for the specific language governing permissions and
17		* limitations under the License.
18		*/
19
20		/*
21		* Definition of CCM:
22		* http://csrc.nist.gov/publications/nistpubs/800-38C/SP800-38C_updated-July20_2007.pdf
23		* RFC 3610 "Counter with CBC-MAC (CCM)"
24		*
25		* Related:
26		* RFC 5116 "An Interface and Algorithms for Authenticated Encryption"
27		*/
28
29		#include "common.h"
30
31		#if defined(MBEDTLS_CCM_C)
32
33		#include "mbedtls/ccm.h"
34		#include "mbedtls/platform_util.h"
35		#include "mbedtls/error.h"
36
37		#include <string.h>
38
39		#if defined(MBEDTLS_PLATFORM_C)
40		#include "mbedtls/platform.h"
41		#else
42		#if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C)
43		#include <stdio.h>
44		#define mbedtls_printf printf
45		#endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */
46		#endif /* MBEDTLS_PLATFORM_C */
47
48		#if !defined(MBEDTLS_CCM_ALT)
49
50
51		/*
52		* Initialize context
53		*/
54		void mbedtls_ccm_init(mbedtls_ccm_context *ctx)
55	0	{
56	0	memset(ctx, 0, sizeof(mbedtls_ccm_context));
57	0	}
58
59		int mbedtls_ccm_setkey(mbedtls_ccm_context *ctx,
60		mbedtls_cipher_id_t cipher,
61		const unsigned char *key,
62		unsigned int keybits)
63	0	{
64	0	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
65	0	const mbedtls_cipher_info_t *cipher_info;
66
67	0	cipher_info = mbedtls_cipher_info_from_values(cipher, keybits,
68	0	MBEDTLS_MODE_ECB);
69	0	if (cipher_info == NULL) {
70	0	return MBEDTLS_ERR_CCM_BAD_INPUT;
71	0	}
72
73	0	if (cipher_info->block_size != 16) {
74	0	return MBEDTLS_ERR_CCM_BAD_INPUT;
75	0	}
76
77	0	mbedtls_cipher_free(&ctx->cipher_ctx);
78
79	0	if ((ret = mbedtls_cipher_setup(&ctx->cipher_ctx, cipher_info)) != 0) {
80	0	return ret;
81	0	}
82
83	0	if ((ret = mbedtls_cipher_setkey(&ctx->cipher_ctx, key, keybits,
84	0	MBEDTLS_ENCRYPT)) != 0) {
85	0	return ret;
86	0	}
87
88	0	return 0;
89	0	}
90
91		/*
92		* Free context
93		*/
94		void mbedtls_ccm_free(mbedtls_ccm_context *ctx)
95	0	{
96	0	if (ctx == NULL) {
97	0	return;
98	0	}
99	0	mbedtls_cipher_free(&ctx->cipher_ctx);
100	0	mbedtls_platform_zeroize(ctx, sizeof(mbedtls_ccm_context));
101	0	}
102
103	0	#define CCM_STATE__CLEAR 0
104	0	#define CCM_STATE__STARTED (1 << 0)
105	0	#define CCM_STATE__LENGTHS_SET (1 << 1)
106	0	#define CCM_STATE__AUTH_DATA_STARTED (1 << 2)
107	0	#define CCM_STATE__AUTH_DATA_FINISHED (1 << 3)
108	0	#define CCM_STATE__ERROR (1 << 4)
109
110		/*
111		* Encrypt or decrypt a partial block with CTR
112		*/
113		static int mbedtls_ccm_crypt(mbedtls_ccm_context *ctx,
114		size_t offset, size_t use_len,
115		const unsigned char *input,
116		unsigned char *output)
117	0	{
118	0	size_t olen = 0;
119	0	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
120	0	unsigned char tmp_buf[16] = { 0 };
121
122	0	if ((ret = mbedtls_cipher_update(&ctx->cipher_ctx, ctx->ctr, 16, tmp_buf,
123	0	&olen)) != 0) {
124	0	ctx->state \|= CCM_STATE__ERROR;
125	0	mbedtls_platform_zeroize(tmp_buf, sizeof(tmp_buf));
126	0	return ret;
127	0	}
128
129	0	mbedtls_xor(output, input, tmp_buf + offset, use_len);
130
131	0	mbedtls_platform_zeroize(tmp_buf, sizeof(tmp_buf));
132	0	return ret;
133	0	}
134
135		static void mbedtls_ccm_clear_state(mbedtls_ccm_context *ctx)
136	0	{
137	0	ctx->state = CCM_STATE__CLEAR;
138	0	memset(ctx->y, 0, 16);
139	0	memset(ctx->ctr, 0, 16);
140	0	}
141
142		static int ccm_calculate_first_block_if_ready(mbedtls_ccm_context *ctx)
143	0	{
144	0	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
145	0	unsigned char i;
146	0	size_t len_left, olen;
147
148		/* length calculation can be done only after both
149		* mbedtls_ccm_starts() and mbedtls_ccm_set_lengths() have been executed
150		*/
151	0	if (!(ctx->state & CCM_STATE__STARTED) \|\| !(ctx->state & CCM_STATE__LENGTHS_SET)) {
152	0	return 0;
153	0	}
154
155		/* CCM expects non-empty tag.
156		* CCM* allows empty tag. For CCM* without tag, ignore plaintext length.
157		*/
158	0	if (ctx->tag_len == 0) {
159	0	if (ctx->mode == MBEDTLS_CCM_STAR_ENCRYPT \|\| ctx->mode == MBEDTLS_CCM_STAR_DECRYPT) {
160	0	ctx->plaintext_len = 0;
161	0	} else {
162	0	return MBEDTLS_ERR_CCM_BAD_INPUT;
163	0	}
164	0	}
165
166		/*
167		* First block:
168		* 0 .. 0 flags
169		* 1 .. iv_len nonce (aka iv) - set by: mbedtls_ccm_starts()
170		* iv_len+1 .. 15 length
171		*
172		* With flags as (bits):
173		* 7 0
174		* 6 add present?
175		* 5 .. 3 (t - 2) / 2
176		* 2 .. 0 q - 1
177		*/
178	0	ctx->y[0] \|= (ctx->add_len > 0) << 6;
179	0	ctx->y[0] \|= ((ctx->tag_len - 2) / 2) << 3;
180	0	ctx->y[0] \|= ctx->q - 1;
181
182	0	for (i = 0, len_left = ctx->plaintext_len; i < ctx->q; i++, len_left >>= 8) {
183	0	ctx->y[15-i] = MBEDTLS_BYTE_0(len_left);
184	0	}
185
186	0	if (len_left > 0) {
187	0	ctx->state \|= CCM_STATE__ERROR;
188	0	return MBEDTLS_ERR_CCM_BAD_INPUT;
189	0	}
190
191		/* Start CBC-MAC with first block*/
192	0	if ((ret = mbedtls_cipher_update(&ctx->cipher_ctx, ctx->y, 16, ctx->y, &olen)) != 0) {
193	0	ctx->state \|= CCM_STATE__ERROR;
194	0	return ret;
195	0	}
196
197	0	return 0;
198	0	}
199
200		int mbedtls_ccm_starts(mbedtls_ccm_context *ctx,
201		int mode,
202		const unsigned char *iv,
203		size_t iv_len)
204	0	{
205		/* Also implies q is within bounds */
206	0	if (iv_len < 7 \|\| iv_len > 13) {
207	0	return MBEDTLS_ERR_CCM_BAD_INPUT;
208	0	}
209
210	0	ctx->mode = mode;
211	0	ctx->q = 16 - 1 - (unsigned char) iv_len;
212
213		/*
214		* Prepare counter block for encryption:
215		* 0 .. 0 flags
216		* 1 .. iv_len nonce (aka iv)
217		* iv_len+1 .. 15 counter (initially 1)
218		*
219		* With flags as (bits):
220		* 7 .. 3 0
221		* 2 .. 0 q - 1
222		*/
223	0	memset(ctx->ctr, 0, 16);
224	0	ctx->ctr[0] = ctx->q - 1;
225	0	memcpy(ctx->ctr + 1, iv, iv_len);
226	0	memset(ctx->ctr + 1 + iv_len, 0, ctx->q);
227	0	ctx->ctr[15] = 1;
228
229		/*
230		* See ccm_calculate_first_block_if_ready() for block layout description
231		*/
232	0	memcpy(ctx->y + 1, iv, iv_len);
233
234	0	ctx->state \|= CCM_STATE__STARTED;
235	0	return ccm_calculate_first_block_if_ready(ctx);
236	0	}
237
238		int mbedtls_ccm_set_lengths(mbedtls_ccm_context *ctx,
239		size_t total_ad_len,
240		size_t plaintext_len,
241		size_t tag_len)
242	0	{
243		/*
244		* Check length requirements: SP800-38C A.1
245		* Additional requirement: a < 2^16 - 2^8 to simplify the code.
246		* 'length' checked later (when writing it to the first block)
247		*
248		* Also, loosen the requirements to enable support for CCM* (IEEE 802.15.4).
249		*/
250	0	if (tag_len == 2 \|\| tag_len > 16 \|\| tag_len % 2 != 0) {
251	0	return MBEDTLS_ERR_CCM_BAD_INPUT;
252	0	}
253
254	0	if (total_ad_len >= 0xFF00) {
255	0	return MBEDTLS_ERR_CCM_BAD_INPUT;
256	0	}
257
258	0	ctx->plaintext_len = plaintext_len;
259	0	ctx->add_len = total_ad_len;
260	0	ctx->tag_len = tag_len;
261	0	ctx->processed = 0;
262
263	0	ctx->state \|= CCM_STATE__LENGTHS_SET;
264	0	return ccm_calculate_first_block_if_ready(ctx);
265	0	}
266
267		int mbedtls_ccm_update_ad(mbedtls_ccm_context *ctx,
268		const unsigned char *add,
269		size_t add_len)
270	0	{
271	0	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
272	0	size_t olen, use_len, offset;
273
274	0	if (ctx->state & CCM_STATE__ERROR) {
275	0	return MBEDTLS_ERR_CCM_BAD_INPUT;
276	0	}
277
278	0	if (add_len > 0) {
279	0	if (ctx->state & CCM_STATE__AUTH_DATA_FINISHED) {
280	0	return MBEDTLS_ERR_CCM_BAD_INPUT;
281	0	}
282
283	0	if (!(ctx->state & CCM_STATE__AUTH_DATA_STARTED)) {
284	0	if (add_len > ctx->add_len) {
285	0	return MBEDTLS_ERR_CCM_BAD_INPUT;
286	0	}
287
288	0	ctx->y[0] ^= (unsigned char) ((ctx->add_len >> 8) & 0xFF);
289	0	ctx->y[1] ^= (unsigned char) ((ctx->add_len) & 0xFF);
290
291	0	ctx->state \|= CCM_STATE__AUTH_DATA_STARTED;
292	0	} else if (ctx->processed + add_len > ctx->add_len) {
293	0	return MBEDTLS_ERR_CCM_BAD_INPUT;
294	0	}
295
296	0	while (add_len > 0) {
297	0	offset = (ctx->processed + 2) % 16; /* account for y[0] and y[1]
298		* holding total auth data length */
299	0	use_len = 16 - offset;
300
301	0	if (use_len > add_len) {
302	0	use_len = add_len;
303	0	}
304
305	0	mbedtls_xor(ctx->y + offset, ctx->y + offset, add, use_len);
306
307	0	ctx->processed += use_len;
308	0	add_len -= use_len;
309	0	add += use_len;
310
311	0	if (use_len + offset == 16 \|\| ctx->processed == ctx->add_len) {
312	0	if ((ret =
313	0	mbedtls_cipher_update(&ctx->cipher_ctx, ctx->y, 16, ctx->y, &olen)) != 0) {
314	0	ctx->state \|= CCM_STATE__ERROR;
315	0	return ret;
316	0	}
317	0	}
318	0	}
319
320	0	if (ctx->processed == ctx->add_len) {
321	0	ctx->state \|= CCM_STATE__AUTH_DATA_FINISHED;
322	0	ctx->processed = 0; // prepare for mbedtls_ccm_update()
323	0	}
324	0	}
325
326	0	return 0;
327	0	}
328
329		int mbedtls_ccm_update(mbedtls_ccm_context *ctx,
330		const unsigned char *input, size_t input_len,
331		unsigned char *output, size_t output_size,
332		size_t *output_len)
333	0	{
334	0	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
335	0	unsigned char i;
336	0	size_t use_len, offset, olen;
337
338	0	unsigned char local_output[16];
339
340	0	if (ctx->state & CCM_STATE__ERROR) {
341	0	return MBEDTLS_ERR_CCM_BAD_INPUT;
342	0	}
343
344		/* Check against plaintext length only if performing operation with
345		* authentication
346		*/
347	0	if (ctx->tag_len != 0 && ctx->processed + input_len > ctx->plaintext_len) {
348	0	return MBEDTLS_ERR_CCM_BAD_INPUT;
349	0	}
350
351	0	if (output_size < input_len) {
352	0	return MBEDTLS_ERR_CCM_BAD_INPUT;
353	0	}
354	0	*output_len = input_len;
355
356	0	ret = 0;
357
358	0	while (input_len > 0) {
359	0	offset = ctx->processed % 16;
360
361	0	use_len = 16 - offset;
362
363	0	if (use_len > input_len) {
364	0	use_len = input_len;
365	0	}
366
367	0	ctx->processed += use_len;
368
369	0	if (ctx->mode == MBEDTLS_CCM_ENCRYPT \|\| \
370	0	ctx->mode == MBEDTLS_CCM_STAR_ENCRYPT) {
371	0	mbedtls_xor(ctx->y + offset, ctx->y + offset, input, use_len);
372
373	0	if (use_len + offset == 16 \|\| ctx->processed == ctx->plaintext_len) {
374	0	if ((ret =
375	0	mbedtls_cipher_update(&ctx->cipher_ctx, ctx->y, 16, ctx->y, &olen)) != 0) {
376	0	ctx->state \|= CCM_STATE__ERROR;
377	0	goto exit;
378	0	}
379	0	}
380
381	0	ret = mbedtls_ccm_crypt(ctx, offset, use_len, input, output);
382	0	if (ret != 0) {
383	0	goto exit;
384	0	}
385	0	}
386
387	0	if (ctx->mode == MBEDTLS_CCM_DECRYPT \|\| \
388	0	ctx->mode == MBEDTLS_CCM_STAR_DECRYPT) {
389		/* Since output may be in shared memory, we cannot be sure that
390		* it will contain what we wrote to it. Therefore, we should avoid using
391		* it as input to any operations.
392		* Write decrypted data to local_output to avoid using output variable as
393		* input in the XOR operation for Y.
394		*/
395	0	ret = mbedtls_ccm_crypt(ctx, offset, use_len, input, local_output);
396	0	if (ret != 0) {
397	0	goto exit;
398	0	}
399
400	0	mbedtls_xor(ctx->y + offset, ctx->y + offset, local_output, use_len);
401
402	0	memcpy(output, local_output, use_len);
403	0	mbedtls_platform_zeroize(local_output, 16);
404
405	0	if (use_len + offset == 16 \|\| ctx->processed == ctx->plaintext_len) {
406	0	if ((ret =
407	0	mbedtls_cipher_update(&ctx->cipher_ctx, ctx->y, 16, ctx->y, &olen)) != 0) {
408	0	ctx->state \|= CCM_STATE__ERROR;
409	0	goto exit;
410	0	}
411	0	}
412	0	}
413
414	0	if (use_len + offset == 16 \|\| ctx->processed == ctx->plaintext_len) {
415	0	for (i = 0; i < ctx->q; i++) {
416	0	if (++(ctx->ctr)[15-i] != 0) {
417	0	break;
418	0	}
419	0	}
420	0	}
421
422	0	input_len -= use_len;
423	0	input += use_len;
424	0	output += use_len;
425	0	}
426
427	0	exit:
428	0	mbedtls_platform_zeroize(local_output, 16);
429
430	0	return ret;
431	0	}
432
433		int mbedtls_ccm_finish(mbedtls_ccm_context *ctx,
434		unsigned char *tag, size_t tag_len)
435	0	{
436	0	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
437	0	unsigned char i;
438
439	0	if (ctx->state & CCM_STATE__ERROR) {
440	0	return MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
441	0	}
442
443	0	if (ctx->add_len > 0 && !(ctx->state & CCM_STATE__AUTH_DATA_FINISHED)) {
444	0	return MBEDTLS_ERR_CCM_BAD_INPUT;
445	0	}
446
447	0	if (ctx->plaintext_len > 0 && ctx->processed != ctx->plaintext_len) {
448	0	return MBEDTLS_ERR_CCM_BAD_INPUT;
449	0	}
450
451		/*
452		* Authentication: reset counter and crypt/mask internal tag
453		*/
454	0	for (i = 0; i < ctx->q; i++) {
455	0	ctx->ctr[15-i] = 0;
456	0	}
457
458	0	ret = mbedtls_ccm_crypt(ctx, 0, 16, ctx->y, ctx->y);
459	0	if (ret != 0) {
460	0	return ret;
461	0	}
462	0	if (tag != NULL) {
463	0	memcpy(tag, ctx->y, tag_len);
464	0	}
465	0	mbedtls_ccm_clear_state(ctx);
466
467	0	return 0;
468	0	}
469
470		/*
471		* Authenticated encryption or decryption
472		*/
473		static int ccm_auth_crypt(mbedtls_ccm_context *ctx, int mode, size_t length,
474		const unsigned char *iv, size_t iv_len,
475		const unsigned char *add, size_t add_len,
476		const unsigned char input, unsigned char output,
477		unsigned char *tag, size_t tag_len)
478	0	{
479	0	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
480	0	size_t olen;
481
482	0	if ((ret = mbedtls_ccm_starts(ctx, mode, iv, iv_len)) != 0) {
483	0	return ret;
484	0	}
485
486	0	if ((ret = mbedtls_ccm_set_lengths(ctx, add_len, length, tag_len)) != 0) {
487	0	return ret;
488	0	}
489
490	0	if ((ret = mbedtls_ccm_update_ad(ctx, add, add_len)) != 0) {
491	0	return ret;
492	0	}
493
494	0	if ((ret = mbedtls_ccm_update(ctx, input, length,
495	0	output, length, &olen)) != 0) {
496	0	return ret;
497	0	}
498
499	0	if ((ret = mbedtls_ccm_finish(ctx, tag, tag_len)) != 0) {
500	0	return ret;
501	0	}
502
503	0	return 0;
504	0	}
505
506		/*
507		* Authenticated encryption
508		*/
509		int mbedtls_ccm_star_encrypt_and_tag(mbedtls_ccm_context *ctx, size_t length,
510		const unsigned char *iv, size_t iv_len,
511		const unsigned char *add, size_t add_len,
512		const unsigned char input, unsigned char output,
513		unsigned char *tag, size_t tag_len)
514	0	{
515	0	return ccm_auth_crypt(ctx, MBEDTLS_CCM_STAR_ENCRYPT, length, iv, iv_len,
516	0	add, add_len, input, output, tag, tag_len);
517	0	}
518
519		int mbedtls_ccm_encrypt_and_tag(mbedtls_ccm_context *ctx, size_t length,
520		const unsigned char *iv, size_t iv_len,
521		const unsigned char *add, size_t add_len,
522		const unsigned char input, unsigned char output,
523		unsigned char *tag, size_t tag_len)
524	0	{
525	0	return ccm_auth_crypt(ctx, MBEDTLS_CCM_ENCRYPT, length, iv, iv_len,
526	0	add, add_len, input, output, tag, tag_len);
527	0	}
528
529		/*
530		* Authenticated decryption
531		*/
532		static int mbedtls_ccm_compare_tags(const unsigned char *tag1,
533		const unsigned char *tag2,
534		size_t tag_len)
535	0	{
536	0	unsigned char i;
537	0	int diff;
538
539		/* Check tag in "constant-time" */
540	0	for (diff = 0, i = 0; i < tag_len; i++) {
541	0	diff \|= tag1[i] ^ tag2[i];
542	0	}
543
544	0	if (diff != 0) {
545	0	return MBEDTLS_ERR_CCM_AUTH_FAILED;
546	0	}
547
548	0	return 0;
549	0	}
550
551		static int ccm_auth_decrypt(mbedtls_ccm_context *ctx, int mode, size_t length,
552		const unsigned char *iv, size_t iv_len,
553		const unsigned char *add, size_t add_len,
554		const unsigned char input, unsigned char output,
555		const unsigned char *tag, size_t tag_len)
556	0	{
557	0	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
558	0	unsigned char check_tag[16];
559
560	0	if ((ret = ccm_auth_crypt(ctx, mode, length,
561	0	iv, iv_len, add, add_len,
562	0	input, output, check_tag, tag_len)) != 0) {
563	0	return ret;
564	0	}
565
566	0	if ((ret = mbedtls_ccm_compare_tags(tag, check_tag, tag_len)) != 0) {
567	0	mbedtls_platform_zeroize(output, length);
568	0	return ret;
569	0	}
570
571	0	return 0;
572	0	}
573
574		int mbedtls_ccm_star_auth_decrypt(mbedtls_ccm_context *ctx, size_t length,
575		const unsigned char *iv, size_t iv_len,
576		const unsigned char *add, size_t add_len,
577		const unsigned char input, unsigned char output,
578		const unsigned char *tag, size_t tag_len)
579	0	{
580	0	return ccm_auth_decrypt(ctx, MBEDTLS_CCM_STAR_DECRYPT, length,
581	0	iv, iv_len, add, add_len,
582	0	input, output, tag, tag_len);
583	0	}
584
585		int mbedtls_ccm_auth_decrypt(mbedtls_ccm_context *ctx, size_t length,
586		const unsigned char *iv, size_t iv_len,
587		const unsigned char *add, size_t add_len,
588		const unsigned char input, unsigned char output,
589		const unsigned char *tag, size_t tag_len)
590	0	{
591	0	return ccm_auth_decrypt(ctx, MBEDTLS_CCM_DECRYPT, length,
592	0	iv, iv_len, add, add_len,
593	0	input, output, tag, tag_len);
594	0	}
595		#endif /* !MBEDTLS_CCM_ALT */
596
597		#if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C)
598		/*
599		* Examples 1 to 3 from SP800-38C Appendix C
600		*/
601
602	0	#define NB_TESTS 3
603	0	#define CCM_SELFTEST_PT_MAX_LEN 24
604	0	#define CCM_SELFTEST_CT_MAX_LEN 32
605		/*
606		* The data is the same for all tests, only the used length changes
607		*/
608		static const unsigned char key_test_data[] = {
609		0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
610		0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f
611		};
612
613		static const unsigned char iv_test_data[] = {
614		0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
615		0x18, 0x19, 0x1a, 0x1b
616		};
617
618		static const unsigned char ad_test_data[] = {
619		0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
620		0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
621		0x10, 0x11, 0x12, 0x13
622		};
623
624		static const unsigned char msg_test_data[CCM_SELFTEST_PT_MAX_LEN] = {
625		0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
626		0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
627		0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
628		};
629
630		static const size_t iv_len_test_data[NB_TESTS] = { 7, 8, 12 };
631		static const size_t add_len_test_data[NB_TESTS] = { 8, 16, 20 };
632		static const size_t msg_len_test_data[NB_TESTS] = { 4, 16, 24 };
633		static const size_t tag_len_test_data[NB_TESTS] = { 4, 6, 8 };
634
635		static const unsigned char res_test_data[NB_TESTS][CCM_SELFTEST_CT_MAX_LEN] = {
636		{ 0x71, 0x62, 0x01, 0x5b, 0x4d, 0xac, 0x25, 0x5d },
637		{ 0xd2, 0xa1, 0xf0, 0xe0, 0x51, 0xea, 0x5f, 0x62,
638		0x08, 0x1a, 0x77, 0x92, 0x07, 0x3d, 0x59, 0x3d,
639		0x1f, 0xc6, 0x4f, 0xbf, 0xac, 0xcd },
640		{ 0xe3, 0xb2, 0x01, 0xa9, 0xf5, 0xb7, 0x1a, 0x7a,
641		0x9b, 0x1c, 0xea, 0xec, 0xcd, 0x97, 0xe7, 0x0b,
642		0x61, 0x76, 0xaa, 0xd9, 0xa4, 0x42, 0x8a, 0xa5,
643		0x48, 0x43, 0x92, 0xfb, 0xc1, 0xb0, 0x99, 0x51 }
644		};
645
646		int mbedtls_ccm_self_test(int verbose)
647	0	{
648	0	mbedtls_ccm_context ctx;
649		/*
650		* Some hardware accelerators require the input and output buffers
651		* would be in RAM, because the flash is not accessible.
652		* Use buffers on the stack to hold the test vectors data.
653		*/
654	0	unsigned char plaintext[CCM_SELFTEST_PT_MAX_LEN];
655	0	unsigned char ciphertext[CCM_SELFTEST_CT_MAX_LEN];
656	0	size_t i;
657	0	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
658
659	0	mbedtls_ccm_init(&ctx);
660
661	0	if (mbedtls_ccm_setkey(&ctx, MBEDTLS_CIPHER_ID_AES, key_test_data,
662	0	8 * sizeof key_test_data) != 0) {
663	0	if (verbose != 0) {
664	0	mbedtls_printf(" CCM: setup failed");
665	0	}
666
667	0	return 1;
668	0	}
669
670	0	for (i = 0; i < NB_TESTS; i++) {
671	0	if (verbose != 0) {
672	0	mbedtls_printf(" CCM-AES #%u: ", (unsigned int) i + 1);
673	0	}
674
675	0	memset(plaintext, 0, CCM_SELFTEST_PT_MAX_LEN);
676	0	memset(ciphertext, 0, CCM_SELFTEST_CT_MAX_LEN);
677	0	memcpy(plaintext, msg_test_data, msg_len_test_data[i]);
678
679	0	ret = mbedtls_ccm_encrypt_and_tag(&ctx, msg_len_test_data[i],
680	0	iv_test_data, iv_len_test_data[i],
681	0	ad_test_data, add_len_test_data[i],
682	0	plaintext, ciphertext,
683	0	ciphertext + msg_len_test_data[i],
684	0	tag_len_test_data[i]);
685
686	0	if (ret != 0 \|\|
687	0	memcmp(ciphertext, res_test_data[i],
688	0	msg_len_test_data[i] + tag_len_test_data[i]) != 0) {
689	0	if (verbose != 0) {
690	0	mbedtls_printf("failed\n");
691	0	}
692
693	0	return 1;
694	0	}
695	0	memset(plaintext, 0, CCM_SELFTEST_PT_MAX_LEN);
696
697	0	ret = mbedtls_ccm_auth_decrypt(&ctx, msg_len_test_data[i],
698	0	iv_test_data, iv_len_test_data[i],
699	0	ad_test_data, add_len_test_data[i],
700	0	ciphertext, plaintext,
701	0	ciphertext + msg_len_test_data[i],
702	0	tag_len_test_data[i]);
703
704	0	if (ret != 0 \|\|
705	0	memcmp(plaintext, msg_test_data, msg_len_test_data[i]) != 0) {
706	0	if (verbose != 0) {
707	0	mbedtls_printf("failed\n");
708	0	}
709
710	0	return 1;
711	0	}
712
713	0	if (verbose != 0) {
714	0	mbedtls_printf("passed\n");
715	0	}
716	0	}
717
718	0	mbedtls_ccm_free(&ctx);
719
720	0	if (verbose != 0) {
721	0	mbedtls_printf("\n");
722	0	}
723
724	0	return 0;
725	0	}
726
727		#endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */
728
729		#endif /* MBEDTLS_CCM_C */