/*
 *  PSA cipher driver entry points
 */
/*
 *  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 "common.h"

#if defined(MBEDTLS_PSA_CRYPTO_C)

#include <psa_crypto_cipher.h>
#include "psa_crypto_core.h"
#include "psa_crypto_random_impl.h"

#include "mbedtls/cipher.h"
#include "mbedtls/error.h"

#include <string.h>

#if (defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DES) || \
     (defined(PSA_CRYPTO_DRIVER_TEST) &&          \
      defined(MBEDTLS_PSA_ACCEL_KEY_TYPE_DES)))
#define BUILTIN_KEY_TYPE_DES 1
#endif

#if (defined(MBEDTLS_PSA_BUILTIN_ALG_CBC_NO_PADDING) || \
     (defined(PSA_CRYPTO_DRIVER_TEST) &&                \
      defined(MBEDTLS_PSA_ACCEL_ALG_CBC_NO_PADDING)))
#define BUILTIN_ALG_CBC_NO_PADDING 1
#endif

#if (defined(MBEDTLS_PSA_BUILTIN_ALG_CBC_PKCS7) || \
     (defined(PSA_CRYPTO_DRIVER_TEST) &&           \
      defined(MBEDTLS_PSA_ACCEL_ALG_CBC_PKCS7)))
#define BUILTIN_ALG_CBC_PKCS7 1
#endif

#if (defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_CHACHA20) || \
     (defined(PSA_CRYPTO_DRIVER_TEST) &&               \
      defined(MBEDTLS_PSA_ACCEL_KEY_TYPE_CHACHA20)))
#define BUILTIN_KEY_TYPE_CHACHA20 1
#endif

const mbedtls_cipher_info_t *mbedtls_cipher_info_from_psa(
    psa_algorithm_t alg,
    psa_key_type_t key_type,
    size_t key_bits,
    mbedtls_cipher_id_t *cipher_id)
{
    mbedtls_cipher_mode_t mode;
    mbedtls_cipher_id_t cipher_id_tmp;

    if (PSA_ALG_IS_AEAD(alg)) {
        alg = PSA_ALG_AEAD_WITH_SHORTENED_TAG(alg, 0);
    }

    if (PSA_ALG_IS_CIPHER(alg) || PSA_ALG_IS_AEAD(alg)) {
        switch (alg) {
            case PSA_ALG_STREAM_CIPHER:
                mode = MBEDTLS_MODE_STREAM;
                break;

            case PSA_ALG_CTR:
                mode = MBEDTLS_MODE_CTR;
                break;

            case PSA_ALG_CFB:
                mode = MBEDTLS_MODE_CFB;
                break;

            case PSA_ALG_OFB:
                mode = MBEDTLS_MODE_OFB;
                break;

            case PSA_ALG_ECB_NO_PADDING:
                mode = MBEDTLS_MODE_ECB;
                break;

            case PSA_ALG_CBC_NO_PADDING:
                mode = MBEDTLS_MODE_CBC;
                break;

            case PSA_ALG_CBC_PKCS7:
                mode = MBEDTLS_MODE_CBC;
                break;

            case PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_CCM, 0):
                mode = MBEDTLS_MODE_CCM;
                break;

            case PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_GCM, 0):
                mode = MBEDTLS_MODE_GCM;
                break;

            case PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_CHACHA20_POLY1305, 0):
                mode = MBEDTLS_MODE_CHACHAPOLY;
                break;

            default:
                return (NULL);
        }
    } else if (alg == PSA_ALG_CMAC) {
        mode = MBEDTLS_MODE_ECB;
    } else {
        return (NULL);
    }

    switch (key_type) {
        case PSA_KEY_TYPE_AES:
            cipher_id_tmp = MBEDTLS_CIPHER_ID_AES;
            break;

        case PSA_KEY_TYPE_DES:

            /* key_bits is 64 for Single-DES, 128 for two-key Triple-DES,
             * and 192 for three-key Triple-DES. */
            if (key_bits == 64) {
                cipher_id_tmp = MBEDTLS_CIPHER_ID_DES;
            } else {
                cipher_id_tmp = MBEDTLS_CIPHER_ID_3DES;
            }

            /* mbedtls doesn't recognize two-key Triple-DES as an algorithm,
             * but two-key Triple-DES is functionally three-key Triple-DES
             * with K1=K3, so that's how we present it to mbedtls. */
            if (key_bits == 128) {
                key_bits = 192;
            }

            break;

        case PSA_KEY_TYPE_CAMELLIA:
            cipher_id_tmp = MBEDTLS_CIPHER_ID_CAMELLIA;
            break;

        case PSA_KEY_TYPE_ARC4:
            cipher_id_tmp = MBEDTLS_CIPHER_ID_ARC4;
            break;

        case PSA_KEY_TYPE_CHACHA20:
            cipher_id_tmp = MBEDTLS_CIPHER_ID_CHACHA20;
            break;

        default:
            return (NULL);
    }

    if (cipher_id != NULL) {
        *cipher_id = cipher_id_tmp;
    }

    return (mbedtls_cipher_info_from_values(cipher_id_tmp,
                                            (int)key_bits, mode));
}

#if defined(MBEDTLS_PSA_BUILTIN_CIPHER) || defined(PSA_CRYPTO_DRIVER_TEST)

static psa_status_t cipher_setup(
    mbedtls_psa_cipher_operation_t *operation,
    const psa_key_attributes_t *attributes,
    const uint8_t *key_buffer, size_t key_buffer_size,
    psa_algorithm_t alg,
    mbedtls_operation_t cipher_operation)
{
    int ret = 0;
    size_t key_bits;
    const mbedtls_cipher_info_t *cipher_info = NULL;
    psa_key_type_t key_type = attributes->core.type;

    (void)key_buffer_size;

    /* Proceed with initializing an mbed TLS cipher context if no driver is
     * available for the given algorithm & key. */
    mbedtls_cipher_init(&operation->cipher);

    operation->alg = alg;
    key_bits = attributes->core.bits;
    cipher_info = mbedtls_cipher_info_from_psa(alg, key_type,
                                               key_bits, NULL);

    if (cipher_info == NULL) {
        return (PSA_ERROR_NOT_SUPPORTED);
    }

    ret = mbedtls_cipher_setup(&operation->cipher, cipher_info);

    if (ret != 0) {
        goto exit;
    }

#if defined(BUILTIN_KEY_TYPE_DES)

    if (key_type == PSA_KEY_TYPE_DES && key_bits == 128) {
        /* Two-key Triple-DES is 3-key Triple-DES with K1=K3 */
        uint8_t keys[24];
        memcpy(keys, key_buffer, 16);
        memcpy(keys + 16, key_buffer, 8);
        ret = mbedtls_cipher_setkey(&operation->cipher,
                                    keys,
                                    192, cipher_operation);
    } else
#endif
    {
        ret = mbedtls_cipher_setkey(&operation->cipher, key_buffer,
                                    (int)key_bits, cipher_operation);
    }

    if (ret != 0) {
        goto exit;
    }

#if defined(BUILTIN_ALG_CBC_NO_PADDING) || \
    defined(BUILTIN_ALG_CBC_PKCS7)

    switch (alg) {
        case PSA_ALG_CBC_NO_PADDING:
            ret = mbedtls_cipher_set_padding_mode(&operation->cipher,
                                                  MBEDTLS_PADDING_NONE);
            break;

        case PSA_ALG_CBC_PKCS7:
            ret = mbedtls_cipher_set_padding_mode(&operation->cipher,
                                                  MBEDTLS_PADDING_PKCS7);
            break;

        default:
            /* The algorithm doesn't involve padding. */
            ret = 0;
            break;
    }

    if (ret != 0) {
        goto exit;
    }

#endif /* BUILTIN_ALG_CBC_NO_PADDING || BUILTIN_ALG_CBC_PKCS7 */

    operation->block_length = (PSA_ALG_IS_STREAM_CIPHER(alg) ? 1 :
                                                               PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type));
    operation->iv_length = PSA_CIPHER_IV_LENGTH(key_type, alg);

exit:
    return (mbedtls_to_psa_error(ret));
}

static psa_status_t cipher_encrypt_setup(
    mbedtls_psa_cipher_operation_t *operation,
    const psa_key_attributes_t *attributes,
    const uint8_t *key_buffer, size_t key_buffer_size,
    psa_algorithm_t alg)
{
    return (cipher_setup(operation, attributes,
                         key_buffer, key_buffer_size,
                         alg, MBEDTLS_ENCRYPT));
}

static psa_status_t cipher_decrypt_setup(
    mbedtls_psa_cipher_operation_t *operation,
    const psa_key_attributes_t *attributes,
    const uint8_t *key_buffer, size_t key_buffer_size,
    psa_algorithm_t alg)
{
    return (cipher_setup(operation, attributes,
                         key_buffer, key_buffer_size,
                         alg, MBEDTLS_DECRYPT));
}

static psa_status_t cipher_set_iv(mbedtls_psa_cipher_operation_t *operation,
                                  const uint8_t *iv, size_t iv_length)
{
    if (iv_length != operation->iv_length) {
        return (PSA_ERROR_INVALID_ARGUMENT);
    }

    return (mbedtls_to_psa_error(
        mbedtls_cipher_set_iv(&operation->cipher,
                              iv, iv_length)));
}

/* Process input for which the algorithm is set to ECB mode. This requires
 * manual processing, since the PSA API is defined as being able to process
 * arbitrary-length calls to psa_cipher_update() with ECB mode, but the
 * underlying mbedtls_cipher_update only takes full blocks. */
static psa_status_t psa_cipher_update_ecb(
    mbedtls_cipher_context_t *ctx,
    const uint8_t *input,
    size_t input_length,
    uint8_t *output,
    size_t output_size,
    size_t *output_length)
{
    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
    size_t block_size = ctx->cipher_info->block_size;
    size_t internal_output_length = 0;
    *output_length = 0;

    if (input_length == 0) {
        status = PSA_SUCCESS;
        goto exit;
    }

    if (ctx->unprocessed_len > 0) {
        /* Fill up to block size, and run the block if there's a full one. */
        size_t bytes_to_copy = block_size - ctx->unprocessed_len;

        if (input_length < bytes_to_copy) {
            bytes_to_copy = input_length;
        }

        memcpy(&(ctx->unprocessed_data[ctx->unprocessed_len]),
               input, bytes_to_copy);
        input_length -= bytes_to_copy;
        input += bytes_to_copy;
        ctx->unprocessed_len += bytes_to_copy;

        if (ctx->unprocessed_len == block_size) {
            status = mbedtls_to_psa_error(
                mbedtls_cipher_update(ctx,
                                      ctx->unprocessed_data,
                                      block_size,
                                      output, &internal_output_length));

            if (status != PSA_SUCCESS) {
                goto exit;
            }

            output += internal_output_length;
            output_size -= internal_output_length;
            *output_length += internal_output_length;
            ctx->unprocessed_len = 0;
        }
    }

    while (input_length >= block_size) {
        /* Run all full blocks we have, one by one */
        status = mbedtls_to_psa_error(
            mbedtls_cipher_update(ctx, input,
                                  block_size,
                                  output, &internal_output_length));

        if (status != PSA_SUCCESS) {
            goto exit;
        }

        input_length -= block_size;
        input += block_size;

        output += internal_output_length;
        output_size -= internal_output_length;
        *output_length += internal_output_length;
    }

    if (input_length > 0) {
        /* Save unprocessed bytes for later processing */
        memcpy(&(ctx->unprocessed_data[ctx->unprocessed_len]),
               input, input_length);
        ctx->unprocessed_len += input_length;
    }

    status = PSA_SUCCESS;

exit:
    return (status);
}

static psa_status_t cipher_update(mbedtls_psa_cipher_operation_t *operation,
                                  const uint8_t *input,
                                  size_t input_length,
                                  uint8_t *output,
                                  size_t output_size,
                                  size_t *output_length)
{
    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
    size_t expected_output_size;

    if (!PSA_ALG_IS_STREAM_CIPHER(operation->alg)) {
        /* Take the unprocessed partial block left over from previous
         * update calls, if any, plus the input to this call. Remove
         * the last partial block, if any. You get the data that will be
         * output in this call. */
        expected_output_size =
            (operation->cipher.unprocessed_len + input_length) / operation->block_length * operation->block_length;
    } else {
        expected_output_size = input_length;
    }

    if (output_size < expected_output_size) {
        return (PSA_ERROR_BUFFER_TOO_SMALL);
    }

    if (operation->alg == PSA_ALG_ECB_NO_PADDING) {
        /* mbedtls_cipher_update has an API inconsistency: it will only
        * process a single block at a time in ECB mode. Abstract away that
        * inconsistency here to match the PSA API behaviour. */
        status = psa_cipher_update_ecb(&operation->cipher,
                                       input,
                                       input_length,
                                       output,
                                       output_size,
                                       output_length);
    } else {
        status = mbedtls_to_psa_error(
            mbedtls_cipher_update(&operation->cipher, input,
                                  input_length, output, output_length));
    }

    return (status);
}

static psa_status_t cipher_finish(mbedtls_psa_cipher_operation_t *operation,
                                  uint8_t *output,
                                  size_t output_size,
                                  size_t *output_length)
{
    psa_status_t status = PSA_ERROR_GENERIC_ERROR;
    uint8_t temp_output_buffer[MBEDTLS_MAX_BLOCK_LENGTH];

    if (operation->cipher.unprocessed_len != 0) {
        if (operation->alg == PSA_ALG_ECB_NO_PADDING ||
            operation->alg == PSA_ALG_CBC_NO_PADDING) {
            status = PSA_ERROR_INVALID_ARGUMENT;
            goto exit;
        }
    }

    status = mbedtls_to_psa_error(
        mbedtls_cipher_finish(&operation->cipher,
                              temp_output_buffer,
                              output_length));

    if (status != PSA_SUCCESS) {
        goto exit;
    }

    if (*output_length == 0)
        ; /* Nothing to copy. Note that output may be NULL in this case. */
    else if (output_size >= *output_length) {
        memcpy(output, temp_output_buffer, *output_length);
    } else {
        status = PSA_ERROR_BUFFER_TOO_SMALL;
    }

exit:
    mbedtls_platform_zeroize(temp_output_buffer,
                             sizeof(temp_output_buffer));

    return (status);
}

static psa_status_t cipher_abort(mbedtls_psa_cipher_operation_t *operation)
{
    /* Sanity check (shouldn't happen: operation->alg should
     * always have been initialized to a valid value). */
    if (!PSA_ALG_IS_CIPHER(operation->alg)) {
        return (PSA_ERROR_BAD_STATE);
    }

    mbedtls_cipher_free(&operation->cipher);

    return (PSA_SUCCESS);
}
#endif /* MBEDTLS_PSA_BUILTIN_CIPHER || PSA_CRYPTO_DRIVER_TEST */

#if defined(MBEDTLS_PSA_BUILTIN_CIPHER)
psa_status_t mbedtls_psa_cipher_encrypt_setup(
    mbedtls_psa_cipher_operation_t *operation,
    const psa_key_attributes_t *attributes,
    const uint8_t *key_buffer, size_t key_buffer_size,
    psa_algorithm_t alg)
{
    return (cipher_encrypt_setup(
        operation, attributes, key_buffer, key_buffer_size, alg));
}

psa_status_t mbedtls_psa_cipher_decrypt_setup(
    mbedtls_psa_cipher_operation_t *operation,
    const psa_key_attributes_t *attributes,
    const uint8_t *key_buffer, size_t key_buffer_size,
    psa_algorithm_t alg)
{
    return (cipher_decrypt_setup(
        operation, attributes, key_buffer, key_buffer_size, alg));
}

psa_status_t mbedtls_psa_cipher_set_iv(mbedtls_psa_cipher_operation_t *operation,
                                       const uint8_t *iv,
                                       size_t iv_length)
{
    return (cipher_set_iv(operation, iv, iv_length));
}

psa_status_t mbedtls_psa_cipher_update(mbedtls_psa_cipher_operation_t *operation,
                                       const uint8_t *input,
                                       size_t input_length,
                                       uint8_t *output,
                                       size_t output_size,
                                       size_t *output_length)
{
    return (cipher_update(operation, input, input_length,
                          output, output_size, output_length));
}

psa_status_t mbedtls_psa_cipher_finish(mbedtls_psa_cipher_operation_t *operation,
                                       uint8_t *output,
                                       size_t output_size,
                                       size_t *output_length)
{
    return (cipher_finish(operation, output, output_size, output_length));
}

psa_status_t mbedtls_psa_cipher_abort(mbedtls_psa_cipher_operation_t *operation)
{
    return (cipher_abort(operation));
}
#endif /* MBEDTLS_PSA_BUILTIN_CIPHER */

/*
 * BEYOND THIS POINT, TEST DRIVER ENTRY POINTS ONLY.
 */

#if defined(PSA_CRYPTO_DRIVER_TEST)
psa_status_t mbedtls_transparent_test_driver_cipher_encrypt_setup(
    mbedtls_psa_cipher_operation_t *operation,
    const psa_key_attributes_t *attributes,
    const uint8_t *key_buffer, size_t key_buffer_size,
    psa_algorithm_t alg)
{
    return (cipher_encrypt_setup(
        operation, attributes, key_buffer, key_buffer_size, alg));
}

psa_status_t mbedtls_transparent_test_driver_cipher_decrypt_setup(
    mbedtls_psa_cipher_operation_t *operation,
    const psa_key_attributes_t *attributes,
    const uint8_t *key_buffer, size_t key_buffer_size,
    psa_algorithm_t alg)
{
    return (cipher_decrypt_setup(
        operation, attributes, key_buffer, key_buffer_size, alg));
}

psa_status_t mbedtls_transparent_test_driver_cipher_set_iv(
    mbedtls_psa_cipher_operation_t *operation,
    const uint8_t *iv, size_t iv_length)
{
    return (cipher_set_iv(operation, iv, iv_length));
}

psa_status_t mbedtls_transparent_test_driver_cipher_update(
    mbedtls_psa_cipher_operation_t *operation,
    const uint8_t *input, size_t input_length,
    uint8_t *output, size_t output_size, size_t *output_length)
{
    return (cipher_update(operation, input, input_length,
                          output, output_size, output_length));
}

psa_status_t mbedtls_transparent_test_driver_cipher_finish(
    mbedtls_psa_cipher_operation_t *operation,
    uint8_t *output, size_t output_size, size_t *output_length)
{
    return (cipher_finish(operation, output, output_size, output_length));
}

psa_status_t mbedtls_transparent_test_driver_cipher_abort(
    mbedtls_psa_cipher_operation_t *operation)
{
    return (cipher_abort(operation));
}
#endif /* PSA_CRYPTO_DRIVER_TEST */

#endif /* MBEDTLS_PSA_CRYPTO_C */