pubkey_test.c

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/*
 * Copyright (C) 2024 Michael Brown <mbrown@fensystems.co.uk>.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 *
 * You can also choose to distribute this program under the terms of
 * the Unmodified Binary Distribution Licence (as given in the file
 * COPYING.UBDL), provided that you have satisfied its requirements.
 */
 
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 
/** @file
 *
 * Public key self-tests
 *
 */
 
/* Forcibly enable assertions */
#undef NDEBUG
 
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <ipxe/crypto.h>
#include <ipxe/test.h>
#include "pubkey_test.h"
 
/** Random data input */
static const uint8_t *pubkey_random;
 
/** Length of random data input */
static size_t pubkey_random_len;
 
/**
 * Get random data input
 *
 * @v data              Output buffer
 * @v len               Length of output buffer
 * @ret rc              Return status code
 */
int pubkey_test_get_random ( void *data, size_t len ) {
 
        /* Sanity check */
        assert ( len <= pubkey_random_len );
 
        /* Return random data */
        memcpy ( data, pubkey_random, len );
 
        /* Consume random data */
        pubkey_random += len;
        pubkey_random_len -= len;
 
        return 0;
}
 
/**
 * Report public key encryption and decryption test result
 *
 * @v test              Public key encryption and decryption test
 * @v file              Test code file
 * @v line              Test code line
 */
void pubkey_okx ( struct pubkey_test *test, const char *file,
                  unsigned int line ) {
        struct pubkey_algorithm *pubkey = test->pubkey;
        struct asn1_builder plaintext;
        struct asn1_builder ciphertext;
 
        /* Test key matching */
        okx ( pubkey_match ( pubkey, &test->private, &test->public ) == 0,
              file, line );
 
        /* Test encrypting with public key to obtain known ciphertext */
        ciphertext.data = NULL;
        ciphertext.len = 0;
        pubkey_random = test->random;
        pubkey_random_len = test->random_len;
        okx ( pubkey_encrypt ( pubkey, &test->public, &test->plaintext,
                               &ciphertext ) == 0, file, line );
        okx ( pubkey_random_len == 0, file, line );
        okx ( asn1_compare ( asn1_built ( &ciphertext ),
                             &test->ciphertext ) == 0, file, line );
        free ( ciphertext.data );
 
        /* Test decrypting with private key to obtain known plaintext */
        plaintext.data = NULL;
        plaintext.len = 0;
        okx ( pubkey_decrypt ( pubkey, &test->private, &test->ciphertext,
                               &plaintext ) == 0, file, line );
        okx ( asn1_compare ( asn1_built ( &plaintext ),
                             &test->plaintext ) == 0, file, line );
        free ( plaintext.data );
 
        /* Test encrypting with private key and decrypting with public key */
        ciphertext.data = NULL;
        ciphertext.len = 0;
        plaintext.data = NULL;
        plaintext.len = 0;
        pubkey_random = test->random;
        pubkey_random_len = test->random_len;
        okx ( pubkey_encrypt ( pubkey, &test->private, &test->plaintext,
                               &ciphertext ) == 0, file, line );
        okx ( pubkey_random_len == 0, file, line );
        okx ( pubkey_decrypt ( pubkey, &test->public,
                               asn1_built ( &ciphertext ),
                               &plaintext ) == 0, file, line );
        okx ( asn1_compare ( asn1_built ( &plaintext ),
                             &test->plaintext ) == 0, file, line );
        free ( ciphertext.data );
        free ( plaintext.data );
 
        /* Test encrypting with public key and decrypting with private key */
        ciphertext.data = NULL;
        ciphertext.len = 0;
        plaintext.data = NULL;
        plaintext.len = 0;
        pubkey_random = test->random;
        pubkey_random_len = test->random_len;
        okx ( pubkey_encrypt ( pubkey, &test->public, &test->plaintext,
                               &ciphertext ) == 0, file, line );
        okx ( pubkey_random_len == 0, file, line );
        okx ( pubkey_decrypt ( pubkey, &test->private,
                               asn1_built ( &ciphertext ),
                               &plaintext ) == 0, file, line );
        okx ( asn1_compare ( asn1_built ( &plaintext ),
                             &test->plaintext ) == 0, file, line );
        free ( ciphertext.data );
        free ( plaintext.data );
}
 
/**
 * Report public key signature test result
 *
 * @v test              Public key signature test
 * @v file              Test code file
 * @v line              Test code line
 */
void pubkey_sign_okx ( struct pubkey_sign_test *test, const char *file,
                       unsigned int line ) {
        struct pubkey_algorithm *pubkey = test->pubkey;
        struct digest_algorithm *digest = test->digest;
        uint8_t digestctx[digest->ctxsize];
        uint8_t digestout[digest->digestsize];
        uint8_t signature[test->signature.len];
        struct asn1_cursor cursor = { signature, sizeof ( signature ) };
        struct asn1_builder builder = { NULL, 0 };
        uint8_t *bad;
 
        /* Test key matching */
        okx ( pubkey_match ( pubkey, &test->private, &test->public ) == 0,
              file, line );
 
        /* Construct digest over plaintext */
        digest_init ( digest, digestctx );
        digest_update ( digest, digestctx, test->plaintext,
                        test->plaintext_len );
        digest_final ( digest, digestctx, digestout );
 
        /* Test verification using public key */
        okx ( pubkey_verify ( pubkey, &test->public, digest, digestout,
                              &test->signature ) == 0, file, line );
 
        /* Test verification failure of modified signature */
        memcpy ( signature, test->signature.data, sizeof ( signature ) );
        bad = ( signature + ( sizeof ( signature ) / 2 ) );
        *bad ^= 0x40;
        okx ( pubkey_verify ( pubkey, &test->public, digest, digestout,
                              &cursor ) != 0, file, line );
        *bad ^= 0x40;
        okx ( pubkey_verify ( pubkey, &test->public, digest, digestout,
                              &cursor ) == 0, file, line );
 
        /* Test signing using private key */
        pubkey_random = test->random;
        pubkey_random_len = test->random_len;
        okx ( pubkey_sign ( pubkey, &test->private, digest, digestout,
                            &builder ) == 0, file, line );
        okx ( pubkey_random_len == 0, file, line );
        okx ( builder.len != 0, file, line );
        okx ( asn1_compare ( asn1_built ( &builder ), &test->signature ) == 0,
              file, line );
 
        /* Test verification of constructed signature */
        okx ( pubkey_verify ( pubkey, &test->public, digest, digestout,
                              asn1_built ( &builder ) ) == 0, file, line );
 
        /* Free signature */
        free ( builder.data );
}