src/tests/hkdf_test.c

/*
 * Copyright (C) 2026 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
 *
 * HKDF self-tests
 *
 * These test vectors are taken from RFC 5869 Appendix A.
 */

/* Forcibly enable assertions */
#undef NDEBUG

#include <string.h>
#include <ipxe/crypto.h>
#include <ipxe/sha1.h>
#include <ipxe/sha256.h>
#include <ipxe/hkdf.h>
#include <ipxe/test.h>
#include "hkdf_test.h"

/**
 * Report an HKDF test result
 *
 * @v test		HKDF test
 * @v file		Test code file
 * @v line		Test code line
 */
void hkdf_okx ( struct hkdf_test *test, const char *file,
		unsigned int line ) {
	size_t digestsize = test->digest->digestsize;
	union {
		uint8_t ikm[test->ikm_len];
		uint8_t salt[test->salt_len];
		uint8_t info[test->info_len];
		uint8_t prk[digestsize];
		uint8_t okm[test->okm_len];
	} overlap;
	uint8_t prk[digestsize];
	uint8_t okm[test->okm_len];
	size_t check_len;

	/* Sanity checks */
	okx ( ( test->salt != NULL ) || ( test->salt_len == 0 ), file, line );
	okx ( ( test->prk_len == 0 ) || ( test->prk_len == digestsize ),
	      file, line );

	/* Test extraction */
	hkdf_extract ( test->digest, test->salt, test->salt_len, test->ikm,
		       test->ikm_len, prk );
	if ( test->prk_len )
		okx ( memcmp ( prk, test->prk, digestsize ) == 0, file, line );

	/* Test expansion */
	hkdf_expand ( test->digest, prk, test->info, test->info_len,
		      okm, test->okm_len );
	okx ( memcmp ( okm, test->okm, test->okm_len ) == 0, file, line );

	/* Test overlap between salt and pseudorandom key */
	if ( test->salt ) {
		memcpy ( overlap.salt, test->salt, test->salt_len );
		hkdf_extract ( test->digest, overlap.salt, test->salt_len,
			       test->ikm, test->ikm_len, overlap.prk );
		okx ( memcmp ( overlap.prk, prk, digestsize ) == 0,
		      file, line );
	}

	/* Test overlap between input keying material and pseudorandom key */
	memcpy ( overlap.ikm, test->ikm, test->ikm_len );
	hkdf_extract ( test->digest, test->salt, test->salt_len, overlap.ikm,
		       test->ikm_len, overlap.prk );
	okx ( memcmp ( overlap.prk, prk, digestsize ) == 0, file, line );

	/* Calculate length for expansion overlap tests */
	check_len = test->okm_len;
	if ( check_len > digestsize )
		check_len = digestsize;

	/* Test overlap between pseudorandom key and output */
	memcpy ( overlap.prk, prk, digestsize );
	hkdf_expand ( test->digest, overlap.prk, test->info, test->info_len,
		      overlap.okm, test->okm_len );
	okx ( memcmp ( overlap.okm, test->okm, check_len ) == 0, file, line );

	/* Test overlap between additional information and output */
	memcpy ( overlap.info, test->info, test->info_len );
	hkdf_expand ( test->digest, prk, overlap.info, test->info_len,
		      overlap.okm, test->okm_len );
	okx ( memcmp ( overlap.okm, test->okm, check_len ) == 0, file, line );
}

/** RFC 5869 test case 1: Basic test case with SHA-256 */
HKDF_TEST ( hkdf_test_1, &sha256_algorithm, 1,
	    IKM ( 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
		  0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
		  0x0b, 0x0b ),
	    SALT ( 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
		   0x0a, 0x0b, 0x0c ),
	    INFO ( 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9 ),
	    PRK ( 0x07, 0x77, 0x09, 0x36, 0x2c, 0x2e, 0x32, 0xdf, 0x0d, 0xdc,
		  0x3f, 0x0d, 0xc4, 0x7b, 0xba, 0x63, 0x90, 0xb6, 0xc7, 0x3b,
		  0xb5, 0x0f, 0x9c, 0x31, 0x22, 0xec, 0x84, 0x4a, 0xd7, 0xc2,
		  0xb3, 0xe5 ),
	    OKM (   0x3c, 0xb2, 0x5f, 0x25, 0xfa, 0xac, 0xd5, 0x7a, 0x90, 0x43,
		    0x4f, 0x64, 0xd0, 0x36, 0x2f, 0x2a, 0x2d, 0x2d, 0x0a, 0x90,
		    0xcf, 0x1a, 0x5a, 0x4c, 0x5d, 0xb0, 0x2d, 0x56, 0xec, 0xc4,
		    0xc5, 0xbf, 0x34, 0x00, 0x72, 0x08, 0xd5, 0xb8, 0x87, 0x18,
		    0x58, 0x65 ) );

/** RFC 5869 test case 2: Test with SHA-256 and longer inputs/outputs */
HKDF_TEST ( hkdf_test_2, &sha256_algorithm, 1,
	    IKM ( 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
		  0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13,
		  0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d,
		  0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
		  0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31,
		  0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b,
		  0x3c, 0x3d, 0x3e, 0x3f, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45,
		  0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f ),
	    SALT ( 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69,
		   0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72, 0x73,
		   0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d,
		   0x7e, 0x7f, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
		   0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 0x90, 0x91,
		   0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b,
		   0x9c, 0x9d, 0x9e, 0x9f, 0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5,
		   0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf ),
	    INFO ( 0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9,
		   0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, 0xc0, 0xc1, 0xc2, 0xc3,
		   0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd,
		   0xce, 0xcf, 0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7,
		   0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf, 0xe0, 0xe1,
		   0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xeb,
		   0xec, 0xed, 0xee, 0xef, 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5,
		   0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff ),
	    PRK (   0x06, 0xa6, 0xb8, 0x8c, 0x58, 0x53, 0x36, 0x1a, 0x06, 0x10,
		    0x4c, 0x9c, 0xeb, 0x35, 0xb4, 0x5c, 0xef, 0x76, 0x00, 0x14,
		    0x90, 0x46, 0x71, 0x01, 0x4a, 0x19, 0x3f, 0x40, 0xc1, 0x5f,
		    0xc2, 0x44 ),
	    OKM ( 0xb1, 0x1e, 0x39, 0x8d, 0xc8, 0x03, 0x27, 0xa1, 0xc8, 0xe7,
		  0xf7, 0x8c, 0x59, 0x6a, 0x49, 0x34, 0x4f, 0x01, 0x2e, 0xda,
		  0x2d, 0x4e, 0xfa, 0xd8, 0xa0, 0x50, 0xcc, 0x4c, 0x19, 0xaf,
		  0xa9, 0x7c, 0x59, 0x04, 0x5a, 0x99, 0xca, 0xc7, 0x82, 0x72,
		  0x71, 0xcb, 0x41, 0xc6, 0x5e, 0x59, 0x0e, 0x09, 0xda, 0x32,
		  0x75, 0x60, 0x0c, 0x2f, 0x09, 0xb8, 0x36, 0x77, 0x93, 0xa9,
		  0xac, 0xa3, 0xdb, 0x71, 0xcc, 0x30, 0xc5, 0x81, 0x79, 0xec,
		  0x3e, 0x87, 0xc1, 0x4c, 0x01, 0xd5, 0xc1, 0xf3, 0x43, 0x4f,
		  0x1d, 0x87 ) );

/** RFC 5869 test case 3: Test with SHA-256 and zero-length salt/info */
HKDF_TEST ( hkdf_test_3, &sha256_algorithm, 1,
	    IKM ( 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
		  0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
		  0x0b, 0x0b ),
	    SALT(), INFO(),
	    PRK ( 0x19, 0xef, 0x24, 0xa3, 0x2c, 0x71, 0x7b, 0x16, 0x7f, 0x33,
		  0xa9, 0x1d, 0x6f, 0x64, 0x8b, 0xdf, 0x96, 0x59, 0x67, 0x76,
		  0xaf, 0xdb, 0x63, 0x77, 0xac, 0x43, 0x4c, 0x1c, 0x29, 0x3c,
		  0xcb, 0x04 ),
	    OKM ( 0x8d, 0xa4, 0xe7, 0x75, 0xa5, 0x63, 0xc1, 0x8f, 0x71, 0x5f,
		  0x80, 0x2a, 0x06, 0x3c, 0x5a, 0x31, 0xb8, 0xa1, 0x1f, 0x5c,
		  0x5e, 0xe1, 0x87, 0x9e, 0xc3, 0x45, 0x4e, 0x5f, 0x3c, 0x73,
		  0x8d, 0x2d, 0x9d, 0x20, 0x13, 0x95, 0xfa, 0xa4, 0xb6, 0x1a,
		  0x96, 0xc8 ) );

/** RFC 5869 test case 4: Basic test case with SHA-1 */
HKDF_TEST ( hkdf_test_4, &sha1_algorithm, 1,
	    IKM ( 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
		  0x0b ),
	    SALT ( 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
		   0x0a, 0x0b, 0x0c ),
	    INFO ( 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9 ),
	    PRK ( 0x9b, 0x6c, 0x18, 0xc4, 0x32, 0xa7, 0xbf, 0x8f, 0x0e, 0x71,
		  0xc8, 0xeb, 0x88, 0xf4, 0xb3, 0x0b, 0xaa, 0x2b, 0xa2, 0x43 ),
	    OKM ( 0x08, 0x5a, 0x01, 0xea, 0x1b, 0x10, 0xf3, 0x69, 0x33, 0x06,
		  0x8b, 0x56, 0xef, 0xa5, 0xad, 0x81, 0xa4, 0xf1, 0x4b, 0x82,
		  0x2f, 0x5b, 0x09, 0x15, 0x68, 0xa9, 0xcd, 0xd4, 0xf1, 0x55,
		  0xfd, 0xa2, 0xc2, 0x2e, 0x42, 0x24, 0x78, 0xd3, 0x05, 0xf3,
		  0xf8, 0x96 ) );

/** RFC 5869 test case 5: Test with SHA-1 and longer inputs/outputs */
HKDF_TEST ( hkdf_test_5, &sha1_algorithm, 1,
	    IKM ( 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
		  0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13,
		  0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d,
		  0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
		  0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31,
		  0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b,
		  0x3c, 0x3d, 0x3e, 0x3f, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45,
		  0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f ),
	    SALT ( 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69,
		   0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72, 0x73,
		   0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d,
		   0x7e, 0x7f, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
		   0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 0x90, 0x91,
		   0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b,
		   0x9c, 0x9d, 0x9e, 0x9f, 0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5,
		   0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf ),
	    INFO ( 0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9,
		   0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, 0xc0, 0xc1, 0xc2, 0xc3,
		   0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd,
		   0xce, 0xcf, 0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7,
		   0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf, 0xe0, 0xe1,
		   0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xeb,
		   0xec, 0xed, 0xee, 0xef, 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5,
		   0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff ),
	    PRK ( 0x8a, 0xda, 0xe0, 0x9a, 0x2a, 0x30, 0x70, 0x59, 0x47, 0x8d,
		  0x30, 0x9b, 0x26, 0xc4, 0x11, 0x5a, 0x22, 0x4c, 0xfa, 0xf6 ),
	    OKM ( 0x0b, 0xd7, 0x70, 0xa7, 0x4d, 0x11, 0x60, 0xf7, 0xc9, 0xf1,
		  0x2c, 0xd5, 0x91, 0x2a, 0x06, 0xeb, 0xff, 0x6a, 0xdc, 0xae,
		  0x89, 0x9d, 0x92, 0x19, 0x1f, 0xe4, 0x30, 0x56, 0x73, 0xba,
		  0x2f, 0xfe, 0x8f, 0xa3, 0xf1, 0xa4, 0xe5, 0xad, 0x79, 0xf3,
		  0xf3, 0x34, 0xb3, 0xb2, 0x02, 0xb2, 0x17, 0x3c, 0x48, 0x6e,
		  0xa3, 0x7c, 0xe3, 0xd3, 0x97, 0xed, 0x03, 0x4c, 0x7f, 0x9d,
		  0xfe, 0xb1, 0x5c, 0x5e, 0x92, 0x73, 0x36, 0xd0, 0x44, 0x1f,
		  0x4c, 0x43, 0x00, 0xe2, 0xcf, 0xf0, 0xd0, 0x90, 0x0b, 0x52,
		  0xd3, 0xb4 ) );

/** RFC 5869 test case 6: Test with SHA-1 and zero-length salt/info */
HKDF_TEST ( hkdf_test_6, &sha1_algorithm, 1,
	    IKM ( 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
		  0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
		  0x0b, 0x0b ),
	    SALT(), INFO(),
	    PRK ( 0xda, 0x8c, 0x8a, 0x73, 0xc7, 0xfa, 0x77, 0x28, 0x8e, 0xc6,
		  0xf5, 0xe7, 0xc2, 0x97, 0x78, 0x6a, 0xa0, 0xd3, 0x2d, 0x01 ),
	    OKM ( 0x0a, 0xc1, 0xaf, 0x70, 0x02, 0xb3, 0xd7, 0x61, 0xd1, 0xe5,
		  0x52, 0x98, 0xda, 0x9d, 0x05, 0x06, 0xb9, 0xae, 0x52, 0x05,
		  0x72, 0x20, 0xa3, 0x06, 0xe0, 0x7b, 0x6b, 0x87, 0xe8, 0xdf,
		  0x21, 0xd0, 0xea, 0x00, 0x03, 0x3d, 0xe0, 0x39, 0x84, 0xd3,
		  0x49, 0x18 ) );

/** RFC 5869 test case 7: Test with SHA-1, salt not provided */
HKDF_TEST ( hkdf_test_7, &sha1_algorithm, 0,
	    IKM ( 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c,
		  0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c,
		  0x0c, 0x0c ),
	    SALT(), INFO(),
	    PRK ( 0x2a, 0xdc, 0xca, 0xda, 0x18, 0x77, 0x9e, 0x7c, 0x20, 0x77,
		  0xad, 0x2e, 0xb1, 0x9d, 0x3f, 0x3e, 0x73, 0x13, 0x85, 0xdd ),
	    OKM ( 0x2c, 0x91, 0x11, 0x72, 0x04, 0xd7, 0x45, 0xf3, 0x50, 0x0d,
		  0x63, 0x6a, 0x62, 0xf6, 0x4f, 0x0a, 0xb3, 0xba, 0xe5, 0x48,
		  0xaa, 0x53, 0xd4, 0x23, 0xb0, 0xd1, 0xf2, 0x7e, 0xbb, 0xa6,
		  0xf5, 0xe5, 0x67, 0x3a, 0x08, 0x1d, 0x70, 0xcc, 0xe7, 0xac,
		  0xfc, 0x48 ) );

/**
 * Perform HKDF self-tests
 *
 */
static void hkdf_test_exec ( void ) {

	hkdf_ok ( &hkdf_test_1 );
	hkdf_ok ( &hkdf_test_2 );
	hkdf_ok ( &hkdf_test_3 );
	hkdf_ok ( &hkdf_test_4 );
	hkdf_ok ( &hkdf_test_5 );
	hkdf_ok ( &hkdf_test_6 );
	hkdf_ok ( &hkdf_test_7 );
}

/** HKDF self-test */
struct self_test hkdf_test __self_test = {
	.name = "hkdf",
	.exec = hkdf_test_exec,
};