programs/psa/crypto_examples.c

/*
 *  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.
 */

#include "psa/crypto.h"
#include <string.h>
#include <stdio.h>
#include <stdlib.h>

#define ASSERT(predicate)                                                   \
    do                                                                        \
    {                                                                         \
        if (!(predicate))                                                 \
        {                                                                     \
            printf("\tassertion failed at %s:%d - '%s'\r\n",         \
                   __FILE__, __LINE__, #predicate);                  \
            goto exit;                                                        \
        }                                                                     \
    } while (0)

#define ASSERT_STATUS(actual, expected)                                     \
    do                                                                        \
    {                                                                         \
        if ((actual) != (expected))                                      \
        {                                                                     \
            printf("\tassertion failed at %s:%d - "                  \
                   "actual:%d expected:%d\r\n", __FILE__, __LINE__,  \
                   (psa_status_t) actual, (psa_status_t) expected); \
            goto exit;                                                        \
        }                                                                     \
    } while (0)

#if !defined(MBEDTLS_PSA_CRYPTO_C) || !defined(MBEDTLS_AES_C) || \
    !defined(MBEDTLS_CIPHER_MODE_CBC) || !defined(MBEDTLS_CIPHER_MODE_CTR) || \
    !defined(MBEDTLS_CIPHER_MODE_WITH_PADDING) || \
    defined(MBEDTLS_PSA_CRYPTO_KEY_ID_ENCODES_OWNER)
int main(void)
{
    printf("MBEDTLS_PSA_CRYPTO_C and/or MBEDTLS_AES_C and/or "
           "MBEDTLS_CIPHER_MODE_CBC and/or MBEDTLS_CIPHER_MODE_CTR "
           "and/or MBEDTLS_CIPHER_MODE_WITH_PADDING "
           "not defined and/or MBEDTLS_PSA_CRYPTO_KEY_ID_ENCODES_OWNER"
           " defined.\r\n");
    return 0;
}
#else

static psa_status_t cipher_operation(psa_cipher_operation_t *operation,
                                     const uint8_t *input,
                                     size_t input_size,
                                     size_t part_size,
                                     uint8_t *output,
                                     size_t output_size,
                                     size_t *output_len)
{
    psa_status_t status;
    size_t bytes_to_write = 0, bytes_written = 0, len = 0;

    *output_len = 0;
    while (bytes_written != input_size) {
        bytes_to_write = (input_size - bytes_written > part_size ?
                          part_size :
                          input_size - bytes_written);

        status = psa_cipher_update(operation, input + bytes_written,
                                   bytes_to_write, output + *output_len,
                                   output_size - *output_len, &len);
        ASSERT_STATUS(status, PSA_SUCCESS);

        bytes_written += bytes_to_write;
        *output_len += len;
    }

    status = psa_cipher_finish(operation, output + *output_len,
                               output_size - *output_len, &len);
    ASSERT_STATUS(status, PSA_SUCCESS);
    *output_len += len;

exit:
    return status;
}

static psa_status_t cipher_encrypt(psa_key_id_t key,
                                   psa_algorithm_t alg,
                                   uint8_t *iv,
                                   size_t iv_size,
                                   const uint8_t *input,
                                   size_t input_size,
                                   size_t part_size,
                                   uint8_t *output,
                                   size_t output_size,
                                   size_t *output_len)
{
    psa_status_t status;
    psa_cipher_operation_t operation = PSA_CIPHER_OPERATION_INIT;
    size_t iv_len = 0;

    memset(&operation, 0, sizeof(operation));
    status = psa_cipher_encrypt_setup(&operation, key, alg);
    ASSERT_STATUS(status, PSA_SUCCESS);

    status = psa_cipher_generate_iv(&operation, iv, iv_size, &iv_len);
    ASSERT_STATUS(status, PSA_SUCCESS);

    status = cipher_operation(&operation, input, input_size, part_size,
                              output, output_size, output_len);
    ASSERT_STATUS(status, PSA_SUCCESS);

exit:
    psa_cipher_abort(&operation);
    return status;
}

static psa_status_t cipher_decrypt(psa_key_id_t key,
                                   psa_algorithm_t alg,
                                   const uint8_t *iv,
                                   size_t iv_size,
                                   const uint8_t *input,
                                   size_t input_size,
                                   size_t part_size,
                                   uint8_t *output,
                                   size_t output_size,
                                   size_t *output_len)
{
    psa_status_t status;
    psa_cipher_operation_t operation = PSA_CIPHER_OPERATION_INIT;

    memset(&operation, 0, sizeof(operation));
    status = psa_cipher_decrypt_setup(&operation, key, alg);
    ASSERT_STATUS(status, PSA_SUCCESS);

    status = psa_cipher_set_iv(&operation, iv, iv_size);
    ASSERT_STATUS(status, PSA_SUCCESS);

    status = cipher_operation(&operation, input, input_size, part_size,
                              output, output_size, output_len);
    ASSERT_STATUS(status, PSA_SUCCESS);

exit:
    psa_cipher_abort(&operation);
    return status;
}

static psa_status_t
cipher_example_encrypt_decrypt_aes_cbc_nopad_1_block(void)
{
    enum {
        block_size = PSA_BLOCK_CIPHER_BLOCK_LENGTH(PSA_KEY_TYPE_AES),
        key_bits = 256,
        part_size = block_size,
    };
    const psa_algorithm_t alg = PSA_ALG_CBC_NO_PADDING;

    psa_status_t status;
    psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
    psa_key_id_t key = 0;
    size_t output_len = 0;
    uint8_t iv[block_size];
    uint8_t input[block_size];
    uint8_t encrypt[block_size];
    uint8_t decrypt[block_size];

    status = psa_generate_random(input, sizeof(input));
    ASSERT_STATUS(status, PSA_SUCCESS);

    psa_set_key_usage_flags(&attributes,
                            PSA_KEY_USAGE_ENCRYPT | PSA_KEY_USAGE_DECRYPT);
    psa_set_key_algorithm(&attributes, alg);
    psa_set_key_type(&attributes, PSA_KEY_TYPE_AES);
    psa_set_key_bits(&attributes, key_bits);

    status = psa_generate_key(&attributes, &key);
    ASSERT_STATUS(status, PSA_SUCCESS);

    status = cipher_encrypt(key, alg, iv, sizeof(iv),
                            input, sizeof(input), part_size,
                            encrypt, sizeof(encrypt), &output_len);
    ASSERT_STATUS(status, PSA_SUCCESS);

    status = cipher_decrypt(key, alg, iv, sizeof(iv),
                            encrypt, output_len, part_size,
                            decrypt, sizeof(decrypt), &output_len);
    ASSERT_STATUS(status, PSA_SUCCESS);

    status = memcmp(input, decrypt, sizeof(input));
    ASSERT_STATUS(status, PSA_SUCCESS);

exit:
    psa_destroy_key(key);
    return status;
}

static psa_status_t cipher_example_encrypt_decrypt_aes_cbc_pkcs7_multi(void)
{
    enum {
        block_size = PSA_BLOCK_CIPHER_BLOCK_LENGTH(PSA_KEY_TYPE_AES),
        key_bits = 256,
        input_size = 100,
        part_size = 10,
    };

    const psa_algorithm_t alg = PSA_ALG_CBC_PKCS7;

    psa_status_t status;
    psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
    psa_key_id_t key = 0;
    size_t output_len = 0;
    uint8_t iv[block_size], input[input_size],
            encrypt[input_size + block_size], decrypt[input_size + block_size];

    status = psa_generate_random(input, sizeof(input));
    ASSERT_STATUS(status, PSA_SUCCESS);

    psa_set_key_usage_flags(&attributes,
                            PSA_KEY_USAGE_ENCRYPT | PSA_KEY_USAGE_DECRYPT);
    psa_set_key_algorithm(&attributes, alg);
    psa_set_key_type(&attributes, PSA_KEY_TYPE_AES);
    psa_set_key_bits(&attributes, key_bits);

    status = psa_generate_key(&attributes, &key);
    ASSERT_STATUS(status, PSA_SUCCESS);

    status = cipher_encrypt(key, alg, iv, sizeof(iv),
                            input, sizeof(input), part_size,
                            encrypt, sizeof(encrypt), &output_len);
    ASSERT_STATUS(status, PSA_SUCCESS);

    status = cipher_decrypt(key, alg, iv, sizeof(iv),
                            encrypt, output_len, part_size,
                            decrypt, sizeof(decrypt), &output_len);
    ASSERT_STATUS(status, PSA_SUCCESS);

    status = memcmp(input, decrypt, sizeof(input));
    ASSERT_STATUS(status, PSA_SUCCESS);

exit:
    psa_destroy_key(key);
    return status;
}

static psa_status_t cipher_example_encrypt_decrypt_aes_ctr_multi(void)
{
    enum {
        block_size = PSA_BLOCK_CIPHER_BLOCK_LENGTH(PSA_KEY_TYPE_AES),
        key_bits = 256,
        input_size = 100,
        part_size = 10,
    };
    const psa_algorithm_t alg = PSA_ALG_CTR;

    psa_status_t status;
    psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
    psa_key_id_t key = 0;
    size_t output_len = 0;
    uint8_t iv[block_size], input[input_size], encrypt[input_size],
            decrypt[input_size];

    status = psa_generate_random(input, sizeof(input));
    ASSERT_STATUS(status, PSA_SUCCESS);

    psa_set_key_usage_flags(&attributes,
                            PSA_KEY_USAGE_ENCRYPT | PSA_KEY_USAGE_DECRYPT);
    psa_set_key_algorithm(&attributes, alg);
    psa_set_key_type(&attributes, PSA_KEY_TYPE_AES);
    psa_set_key_bits(&attributes, key_bits);

    status = psa_generate_key(&attributes, &key);
    ASSERT_STATUS(status, PSA_SUCCESS);

    status = cipher_encrypt(key, alg, iv, sizeof(iv),
                            input, sizeof(input), part_size,
                            encrypt, sizeof(encrypt), &output_len);
    ASSERT_STATUS(status, PSA_SUCCESS);

    status = cipher_decrypt(key, alg, iv, sizeof(iv),
                            encrypt, output_len, part_size,
                            decrypt, sizeof(decrypt), &output_len);
    ASSERT_STATUS(status, PSA_SUCCESS);

    status = memcmp(input, decrypt, sizeof(input));
    ASSERT_STATUS(status, PSA_SUCCESS);

exit:
    psa_destroy_key(key);
    return status;
}

static void cipher_examples(void)
{
    psa_status_t status;

    printf("cipher encrypt/decrypt AES CBC no padding:\r\n");
    status = cipher_example_encrypt_decrypt_aes_cbc_nopad_1_block();
    if (status == PSA_SUCCESS) {
        printf("\tsuccess!\r\n");
    }

    printf("cipher encrypt/decrypt AES CBC PKCS7 multipart:\r\n");
    status = cipher_example_encrypt_decrypt_aes_cbc_pkcs7_multi();
    if (status == PSA_SUCCESS) {
        printf("\tsuccess!\r\n");
    }

    printf("cipher encrypt/decrypt AES CTR multipart:\r\n");
    status = cipher_example_encrypt_decrypt_aes_ctr_multi();
    if (status == PSA_SUCCESS) {
        printf("\tsuccess!\r\n");
    }
}

int main(void)
{
    ASSERT(psa_crypto_init() == PSA_SUCCESS);
    cipher_examples();
exit:
    mbedtls_psa_crypto_free();
    return 0;
}
#endif /* MBEDTLS_PSA_CRYPTO_C && MBEDTLS_AES_C && MBEDTLS_CIPHER_MODE_CBC &&
          MBEDTLS_CIPHER_MODE_CTR && MBEDTLS_CIPHER_MODE_WITH_PADDING */