pk_encrypt.c

/*
 *  RSA simple data encryption program
 *
 *  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 "mbedtls/build_info.h"

#include "mbedtls/platform.h"

#if defined(MBEDTLS_BIGNUM_C) && defined(MBEDTLS_PK_PARSE_C) && \
    defined(MBEDTLS_ENTROPY_C) && defined(MBEDTLS_FS_IO) && \
    defined(MBEDTLS_CTR_DRBG_C)
#include "mbedtls/error.h"
#include "mbedtls/pk.h"
#include "mbedtls/entropy.h"
#include "mbedtls/ctr_drbg.h"

#include <stdio.h>
#include <string.h>
#endif

#if !defined(MBEDTLS_BIGNUM_C) || !defined(MBEDTLS_PK_PARSE_C) ||  \
    !defined(MBEDTLS_ENTROPY_C) || !defined(MBEDTLS_FS_IO) || \
    !defined(MBEDTLS_CTR_DRBG_C)
int main(void)
{
    mbedtls_printf("MBEDTLS_BIGNUM_C and/or MBEDTLS_PK_PARSE_C and/or "
                   "MBEDTLS_ENTROPY_C and/or MBEDTLS_FS_IO and/or "
                   "MBEDTLS_CTR_DRBG_C not defined.\n");
    mbedtls_exit(0);
}
#else


int main(int argc, char *argv[])
{
    FILE *f;
    int ret = 1;
    int exit_code = MBEDTLS_EXIT_FAILURE;
    size_t i, olen = 0;
    mbedtls_pk_context pk;
    mbedtls_entropy_context entropy;
    mbedtls_ctr_drbg_context ctr_drbg;
    unsigned char input[1024];
    unsigned char buf[512];
    const char *pers = "mbedtls_pk_encrypt";

    mbedtls_ctr_drbg_init(&ctr_drbg);
    mbedtls_entropy_init(&entropy);
    mbedtls_pk_init(&pk);

    if (argc != 3) {
        mbedtls_printf("usage: mbedtls_pk_encrypt <key_file> <string of max 100 characters>\n");

#if defined(_WIN32)
        mbedtls_printf("\n");
#endif

        goto exit;
    }

    mbedtls_printf("\n  . Seeding the random number generator...");
    fflush(stdout);

    if ((ret = mbedtls_ctr_drbg_seed(&ctr_drbg, mbedtls_entropy_func,
                                     &entropy, (const unsigned char *) pers,
                                     strlen(pers))) != 0) {
        mbedtls_printf(" failed\n  ! mbedtls_ctr_drbg_seed returned -0x%04x\n",
                       (unsigned int) -ret);
        goto exit;
    }

    mbedtls_printf("\n  . Reading public key from '%s'", argv[1]);
    fflush(stdout);

    if ((ret = mbedtls_pk_parse_public_keyfile(&pk, argv[1])) != 0) {
        mbedtls_printf(" failed\n  ! mbedtls_pk_parse_public_keyfile returned -0x%04x\n",
                       (unsigned int) -ret);
        goto exit;
    }

    if (strlen(argv[2]) > 100) {
        mbedtls_printf(" Input data larger than 100 characters.\n\n");
        goto exit;
    }

    memcpy(input, argv[2], strlen(argv[2]));

    /*
     * Calculate the RSA encryption of the hash.
     */
    mbedtls_printf("\n  . Generating the encrypted value");
    fflush(stdout);

    if ((ret = mbedtls_pk_encrypt(&pk, input, strlen(argv[2]),
                                  buf, &olen, sizeof(buf),
                                  mbedtls_ctr_drbg_random, &ctr_drbg)) != 0) {
        mbedtls_printf(" failed\n  ! mbedtls_pk_encrypt returned -0x%04x\n",
                       (unsigned int) -ret);
        goto exit;
    }

    /*
     * Write the signature into result-enc.txt
     */
    if ((f = fopen("result-enc.txt", "wb+")) == NULL) {
        mbedtls_printf(" failed\n  ! Could not create %s\n\n",
                       "result-enc.txt");
        ret = 1;
        goto exit;
    }

    for (i = 0; i < olen; i++) {
        mbedtls_fprintf(f, "%02X%s", buf[i],
                        (i + 1) % 16 == 0 ? "\r\n" : " ");
    }

    fclose(f);

    mbedtls_printf("\n  . Done (created \"%s\")\n\n", "result-enc.txt");

    exit_code = MBEDTLS_EXIT_SUCCESS;

exit:

    mbedtls_pk_free(&pk);
    mbedtls_entropy_free(&entropy);
    mbedtls_ctr_drbg_free(&ctr_drbg);

#if defined(MBEDTLS_ERROR_C)
    if (exit_code != MBEDTLS_EXIT_SUCCESS) {
        mbedtls_strerror(ret, (char *) buf, sizeof(buf));
        mbedtls_printf("  !  Last error was: %s\n", buf);
    }
#endif

    mbedtls_exit(exit_code);
}
#endif /* MBEDTLS_BIGNUM_C && MBEDTLS_PK_PARSE_C && MBEDTLS_ENTROPY_C &&
          MBEDTLS_FS_IO && MBEDTLS_CTR_DRBG_C */