mpi_demo.c (2851B)
1 /* 2 * Simple MPI demonstration program 3 * 4 * Copyright The Mbed TLS Contributors 5 * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later 6 */ 7 8 #include "mbedtls/build_info.h" 9 10 #include "mbedtls/platform.h" 11 12 #if defined(MBEDTLS_BIGNUM_C) && defined(MBEDTLS_FS_IO) 13 #include "mbedtls/bignum.h" 14 15 #include <stdio.h> 16 #endif 17 18 #if !defined(MBEDTLS_BIGNUM_C) || !defined(MBEDTLS_FS_IO) 19 int main(void) 20 { 21 mbedtls_printf("MBEDTLS_BIGNUM_C and/or MBEDTLS_FS_IO not defined.\n"); 22 mbedtls_exit(0); 23 } 24 #else 25 26 27 int main(void) 28 { 29 int ret = 1; 30 int exit_code = MBEDTLS_EXIT_FAILURE; 31 mbedtls_mpi E, P, Q, N, H, D, X, Y, Z; 32 33 mbedtls_mpi_init(&E); mbedtls_mpi_init(&P); mbedtls_mpi_init(&Q); mbedtls_mpi_init(&N); 34 mbedtls_mpi_init(&H); mbedtls_mpi_init(&D); mbedtls_mpi_init(&X); mbedtls_mpi_init(&Y); 35 mbedtls_mpi_init(&Z); 36 37 MBEDTLS_MPI_CHK(mbedtls_mpi_read_string(&P, 10, "2789")); 38 MBEDTLS_MPI_CHK(mbedtls_mpi_read_string(&Q, 10, "3203")); 39 MBEDTLS_MPI_CHK(mbedtls_mpi_read_string(&E, 10, "257")); 40 MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&N, &P, &Q)); 41 42 mbedtls_printf("\n Public key:\n\n"); 43 MBEDTLS_MPI_CHK(mbedtls_mpi_write_file(" N = ", &N, 10, NULL)); 44 MBEDTLS_MPI_CHK(mbedtls_mpi_write_file(" E = ", &E, 10, NULL)); 45 46 mbedtls_printf("\n Private key:\n\n"); 47 MBEDTLS_MPI_CHK(mbedtls_mpi_write_file(" P = ", &P, 10, NULL)); 48 MBEDTLS_MPI_CHK(mbedtls_mpi_write_file(" Q = ", &Q, 10, NULL)); 49 50 #if defined(MBEDTLS_GENPRIME) 51 MBEDTLS_MPI_CHK(mbedtls_mpi_sub_int(&P, &P, 1)); 52 MBEDTLS_MPI_CHK(mbedtls_mpi_sub_int(&Q, &Q, 1)); 53 MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&H, &P, &Q)); 54 MBEDTLS_MPI_CHK(mbedtls_mpi_inv_mod(&D, &E, &H)); 55 56 mbedtls_mpi_write_file(" D = E^-1 mod (P-1)*(Q-1) = ", 57 &D, 10, NULL); 58 #else 59 mbedtls_printf("\nTest skipped (MBEDTLS_GENPRIME not defined).\n\n"); 60 #endif 61 MBEDTLS_MPI_CHK(mbedtls_mpi_read_string(&X, 10, "55555")); 62 MBEDTLS_MPI_CHK(mbedtls_mpi_exp_mod(&Y, &X, &E, &N, NULL)); 63 MBEDTLS_MPI_CHK(mbedtls_mpi_exp_mod(&Z, &Y, &D, &N, NULL)); 64 65 mbedtls_printf("\n RSA operation:\n\n"); 66 MBEDTLS_MPI_CHK(mbedtls_mpi_write_file(" X (plaintext) = ", &X, 10, NULL)); 67 MBEDTLS_MPI_CHK(mbedtls_mpi_write_file(" Y (ciphertext) = X^E mod N = ", &Y, 10, NULL)); 68 MBEDTLS_MPI_CHK(mbedtls_mpi_write_file(" Z (decrypted) = Y^D mod N = ", &Z, 10, NULL)); 69 mbedtls_printf("\n"); 70 71 exit_code = MBEDTLS_EXIT_SUCCESS; 72 73 cleanup: 74 mbedtls_mpi_free(&E); mbedtls_mpi_free(&P); mbedtls_mpi_free(&Q); mbedtls_mpi_free(&N); 75 mbedtls_mpi_free(&H); mbedtls_mpi_free(&D); mbedtls_mpi_free(&X); mbedtls_mpi_free(&Y); 76 mbedtls_mpi_free(&Z); 77 78 if (exit_code != MBEDTLS_EXIT_SUCCESS) { 79 mbedtls_printf("\nAn error occurred.\n"); 80 } 81 82 mbedtls_exit(exit_code); 83 } 84 #endif /* MBEDTLS_BIGNUM_C && MBEDTLS_FS_IO */