Contributors: 2
Author Tokens Token Proportion Commits Commit Proportion
Hannes Reinecke 1739 83.97% 1 16.67%
Eric Biggers 332 16.03% 5 83.33%
Total 2071 6 


// SPDX-License-Identifier: GPL-2.0
/*
 * Implementation of HKDF ("HMAC-based Extract-and-Expand Key Derivation
 * Function"), aka RFC 5869.  See also the original paper (Krawczyk 2010):
 * "Cryptographic Extraction and Key Derivation: The HKDF Scheme".
 *
 * Copyright 2019 Google LLC
 */

#include <crypto/internal/hash.h>
#include <crypto/sha2.h>
#include <crypto/hkdf.h>
#include <linux/module.h>

/*
 * HKDF consists of two steps:
 *
 * 1. HKDF-Extract: extract a pseudorandom key from the input keying material
 *    and optional salt.
 * 2. HKDF-Expand: expand the pseudorandom key into output keying material of
 *    any length, parameterized by an application-specific info string.
 *
 */

/**
 * hkdf_extract - HKDF-Extract (RFC 5869 section 2.2)
 * @hmac_tfm: an HMAC transform using the hash function desired for HKDF.  The
 *            caller is responsible for setting the @prk afterwards.
 * @ikm: input keying material
 * @ikmlen: length of @ikm
 * @salt: input salt value
 * @saltlen: length of @salt
 * @prk: resulting pseudorandom key
 *
 * Extracts a pseudorandom key @prk from the input keying material
 * @ikm with length @ikmlen and salt @salt with length @saltlen.
 * The length of @prk is given by the digest size of @hmac_tfm.
 * For an 'unsalted' version of HKDF-Extract @salt must be set
 * to all zeroes and @saltlen must be set to the length of @prk.
 *
 * Returns 0 on success with the pseudorandom key stored in @prk,
 * or a negative errno value otherwise.
 */
int hkdf_extract(struct crypto_shash *hmac_tfm, const u8 *ikm,
		 unsigned int ikmlen, const u8 *salt, unsigned int saltlen,
		 u8 *prk)
{
	int err;

	err = crypto_shash_setkey(hmac_tfm, salt, saltlen);
	if (!err)
		err = crypto_shash_tfm_digest(hmac_tfm, ikm, ikmlen, prk);

	return err;
}
EXPORT_SYMBOL_GPL(hkdf_extract);

/**
 * hkdf_expand - HKDF-Expand (RFC 5869 section 2.3)
 * @hmac_tfm: hash context keyed with pseudorandom key
 * @info: application-specific information
 * @infolen: length of @info
 * @okm: output keying material
 * @okmlen: length of @okm
 *
 * This expands the pseudorandom key, which was already keyed into @hmac_tfm,
 * into @okmlen bytes of output keying material parameterized by the
 * application-specific @info of length @infolen bytes.
 * This is thread-safe and may be called by multiple threads in parallel.
 *
 * Returns 0 on success with output keying material stored in @okm,
 * or a negative errno value otherwise.
 */
int hkdf_expand(struct crypto_shash *hmac_tfm,
		const u8 *info, unsigned int infolen,
		u8 *okm, unsigned int okmlen)
{
	SHASH_DESC_ON_STACK(desc, hmac_tfm);
	unsigned int i, hashlen = crypto_shash_digestsize(hmac_tfm);
	int err;
	const u8 *prev = NULL;
	u8 counter = 1;
	u8 tmp[HASH_MAX_DIGESTSIZE] = {};

	if (WARN_ON(okmlen > 255 * hashlen))
		return -EINVAL;

	desc->tfm = hmac_tfm;

	for (i = 0; i < okmlen; i += hashlen) {
		err = crypto_shash_init(desc);
		if (err)
			goto out;

		if (prev) {
			err = crypto_shash_update(desc, prev, hashlen);
			if (err)
				goto out;
		}

		if (infolen) {
			err = crypto_shash_update(desc, info, infolen);
			if (err)
				goto out;
		}

		BUILD_BUG_ON(sizeof(counter) != 1);
		if (okmlen - i < hashlen) {
			err = crypto_shash_finup(desc, &counter, 1, tmp);
			if (err)
				goto out;
			memcpy(&okm[i], tmp, okmlen - i);
			memzero_explicit(tmp, sizeof(tmp));
		} else {
			err = crypto_shash_finup(desc, &counter, 1, &okm[i]);
			if (err)
				goto out;
		}
		counter++;
		prev = &okm[i];
	}
	err = 0;
out:
	if (unlikely(err))
		memzero_explicit(okm, okmlen); /* so caller doesn't need to */
	shash_desc_zero(desc);
	memzero_explicit(tmp, HASH_MAX_DIGESTSIZE);
	return err;
}
EXPORT_SYMBOL_GPL(hkdf_expand);

struct hkdf_testvec {
	const char *test;
	const u8 *ikm;
	const u8 *salt;
	const u8 *info;
	const u8 *prk;
	const u8 *okm;
	u16 ikm_size;
	u16 salt_size;
	u16 info_size;
	u16 prk_size;
	u16 okm_size;
};

/*
 * HKDF test vectors from RFC5869
 *
 * Additional HKDF test vectors from
 * https://github.com/brycx/Test-Vector-Generation/blob/master/HKDF/hkdf-hmac-sha2-test-vectors.md
 */
static const struct hkdf_testvec hkdf_sha256_tv[] = {
	{
		.test = "basic hdkf test",
		.ikm  = "\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b"
			"\x0b\x0b\x0b\x0b\x0b\x0b",
		.ikm_size = 22,
		.salt = "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c",
		.salt_size = 13,
		.info = "\xf0\xf1\xf2\xf3\xf4\xf5\xf6\xf7\xf8\xf9",
		.info_size = 10,
		.prk = "\x07\x77\x09\x36\x2c\x2e\x32\xdf\x0d\xdc\x3f\x0d\xc4\x7b\xba\x63"
			"\x90\xb6\xc7\x3b\xb5\x0f\x9c\x31\x22\xec\x84\x4a\xd7\xc2\xb3\xe5",
		.prk_size = 32,
		.okm  = "\x3c\xb2\x5f\x25\xfa\xac\xd5\x7a\x90\x43\x4f\x64\xd0\x36\x2f\x2a"
			"\x2d\x2d\x0a\x90\xcf\x1a\x5a\x4c\x5d\xb0\x2d\x56\xec\xc4\xc5\xbf"
			"\x34\x00\x72\x08\xd5\xb8\x87\x18\x58\x65",
		.okm_size = 42,
	}, {
		.test = "hkdf test with long input",
		.ikm  = "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f"
			"\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"
			"\x20\x21\x22\x23\x24\x25\x26\x27\x28\x29\x2a\x2b\x2c\x2d\x2e\x2f"
			"\x30\x31\x32\x33\x34\x35\x36\x37\x38\x39\x3a\x3b\x3c\x3d\x3e\x3f"
			"\x40\x41\x42\x43\x44\x45\x46\x47\x48\x49\x4a\x4b\x4c\x4d\x4e\x4f",
		.ikm_size = 80,
		.salt = "\x60\x61\x62\x63\x64\x65\x66\x67\x68\x69\x6a\x6b\x6c\x6d\x6e\x6f"
			"\x70\x71\x72\x73\x74\x75\x76\x77\x78\x79\x7a\x7b\x7c\x7d\x7e\x7f"
			"\x80\x81\x82\x83\x84\x85\x86\x87\x88\x89\x8a\x8b\x8c\x8d\x8e\x8f"
			"\x90\x91\x92\x93\x94\x95\x96\x97\x98\x99\x9a\x9b\x9c\x9d\x9e\x9f"
			"\xa0\xa1\xa2\xa3\xa4\xa5\xa6\xa7\xa8\xa9\xaa\xab\xac\xad\xae\xaf",
		.salt_size = 80,
		.info = "\xb0\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9\xba\xbb\xbc\xbd\xbe\xbf"
			"\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7\xc8\xc9\xca\xcb\xcc\xcd\xce\xcf"
			"\xd0\xd1\xd2\xd3\xd4\xd5\xd6\xd7\xd8\xd9\xda\xdb\xdc\xdd\xde\xdf"
			"\xe0\xe1\xe2\xe3\xe4\xe5\xe6\xe7\xe8\xe9\xea\xeb\xec\xed\xee\xef"
			"\xf0\xf1\xf2\xf3\xf4\xf5\xf6\xf7\xf8\xf9\xfa\xfb\xfc\xfd\xfe\xff",
		.info_size = 80,
		.prk  = "\x06\xa6\xb8\x8c\x58\x53\x36\x1a\x06\x10\x4c\x9c\xeb\x35\xb4\x5c"
			"\xef\x76\x00\x14\x90\x46\x71\x01\x4a\x19\x3f\x40\xc1\x5f\xc2\x44",
		.prk_size = 32,
		.okm  = "\xb1\x1e\x39\x8d\xc8\x03\x27\xa1\xc8\xe7\xf7\x8c\x59\x6a\x49\x34"
			"\x4f\x01\x2e\xda\x2d\x4e\xfa\xd8\xa0\x50\xcc\x4c\x19\xaf\xa9\x7c"
			"\x59\x04\x5a\x99\xca\xc7\x82\x72\x71\xcb\x41\xc6\x5e\x59\x0e\x09"
			"\xda\x32\x75\x60\x0c\x2f\x09\xb8\x36\x77\x93\xa9\xac\xa3\xdb\x71"
			"\xcc\x30\xc5\x81\x79\xec\x3e\x87\xc1\x4c\x01\xd5\xc1\xf3\x43\x4f"
			"\x1d\x87",
		.okm_size = 82,
	}, {
		.test = "hkdf test with zero salt and info",
		.ikm  = "\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b"
			"\x0b\x0b\x0b\x0b\x0b\x0b",
		.ikm_size = 22,
		.salt = NULL,
		.salt_size = 0,
		.info = NULL,
		.info_size = 0,
		.prk  = "\x19\xef\x24\xa3\x2c\x71\x7b\x16\x7f\x33\xa9\x1d\x6f\x64\x8b\xdf"
			"\x96\x59\x67\x76\xaf\xdb\x63\x77\xac\x43\x4c\x1c\x29\x3c\xcb\x04",
		.prk_size = 32,
		.okm  = "\x8d\xa4\xe7\x75\xa5\x63\xc1\x8f\x71\x5f\x80\x2a\x06\x3c\x5a\x31"
			"\xb8\xa1\x1f\x5c\x5e\xe1\x87\x9e\xc3\x45\x4e\x5f\x3c\x73\x8d\x2d"
			"\x9d\x20\x13\x95\xfa\xa4\xb6\x1a\x96\xc8",
		.okm_size = 42,
	}, {
		.test = "hkdf test with short input",
		.ikm  = "\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b",
		.ikm_size = 11,
		.salt = "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c",
		.salt_size = 13,
		.info = "\xf0\xf1\xf2\xf3\xf4\xf5\xf6\xf7\xf8\xf9",
		.info_size = 10,
		.prk  = "\x82\x65\xf6\x9d\x7f\xf7\xe5\x01\x37\x93\x01\x5c\xa0\xef\x92\x0c"
			"\xb1\x68\x21\x99\xc8\xbc\x3a\x00\xda\x0c\xab\x47\xb7\xb0\x0f\xdf",
		.prk_size = 32,
		.okm  = "\x58\xdc\xe1\x0d\x58\x01\xcd\xfd\xa8\x31\x72\x6b\xfe\xbc\xb7\x43"
			"\xd1\x4a\x7e\xe8\x3a\xa0\x57\xa9\x3d\x59\xb0\xa1\x31\x7f\xf0\x9d"
			"\x10\x5c\xce\xcf\x53\x56\x92\xb1\x4d\xd5",
		.okm_size = 42,
	}, {
		.test = "unsalted hkdf test with zero info",
		.ikm  = "\x0c\x0c\x0c\x0c\x0c\x0c\x0c\x0c\x0c\x0c\x0c\x0c\x0c\x0c\x0c\x0c"
			"\x0c\x0c\x0c\x0c\x0c\x0c",
		.ikm_size = 22,
		.salt = "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
			"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
		.salt_size = 32,
		.info = NULL,
		.info_size = 0,
		.prk  = "\xaa\x84\x1e\x1f\x35\x74\xf3\x2d\x13\xfb\xa8\x00\x5f\xcd\x9b\x8d"
			"\x77\x67\x82\xa5\xdf\xa1\x92\x38\x92\xfd\x8b\x63\x5d\x3a\x89\xdf",
		.prk_size = 32,
		.okm  = "\x59\x68\x99\x17\x9a\xb1\xbc\x00\xa7\xc0\x37\x86\xff\x43\xee\x53"
			"\x50\x04\xbe\x2b\xb9\xbe\x68\xbc\x14\x06\x63\x6f\x54\xbd\x33\x8a"
			"\x66\xa2\x37\xba\x2a\xcb\xce\xe3\xc9\xa7",
		.okm_size = 42,
	}
};

static const struct hkdf_testvec hkdf_sha384_tv[] = {
	{
		.test = "basic hkdf test",
		.ikm  = "\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b"
			"\x0b\x0b\x0b\x0b\x0b\x0b",
		.ikm_size = 22,
		.salt = "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c",
		.salt_size = 13,
		.info = "\xf0\xf1\xf2\xf3\xf4\xf5\xf6\xf7\xf8\xf9",
		.info_size = 10,
		.prk  = "\x70\x4b\x39\x99\x07\x79\xce\x1d\xc5\x48\x05\x2c\x7d\xc3\x9f\x30"
			"\x35\x70\xdd\x13\xfb\x39\xf7\xac\xc5\x64\x68\x0b\xef\x80\xe8\xde"
			"\xc7\x0e\xe9\xa7\xe1\xf3\xe2\x93\xef\x68\xec\xeb\x07\x2a\x5a\xde",
		.prk_size = 48,
		.okm  = "\x9b\x50\x97\xa8\x60\x38\xb8\x05\x30\x90\x76\xa4\x4b\x3a\x9f\x38"
			"\x06\x3e\x25\xb5\x16\xdc\xbf\x36\x9f\x39\x4c\xfa\xb4\x36\x85\xf7"
			"\x48\xb6\x45\x77\x63\xe4\xf0\x20\x4f\xc5",
		.okm_size = 42,
	}, {
		.test = "hkdf test with long input",
		.ikm  = "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f"
			"\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"
			"\x20\x21\x22\x23\x24\x25\x26\x27\x28\x29\x2a\x2b\x2c\x2d\x2e\x2f"
			"\x30\x31\x32\x33\x34\x35\x36\x37\x38\x39\x3a\x3b\x3c\x3d\x3e\x3f"
			"\x40\x41\x42\x43\x44\x45\x46\x47\x48\x49\x4a\x4b\x4c\x4d\x4e\x4f",
		.ikm_size = 80,
		.salt = "\x60\x61\x62\x63\x64\x65\x66\x67\x68\x69\x6a\x6b\x6c\x6d\x6e\x6f"
			"\x70\x71\x72\x73\x74\x75\x76\x77\x78\x79\x7a\x7b\x7c\x7d\x7e\x7f"
			"\x80\x81\x82\x83\x84\x85\x86\x87\x88\x89\x8a\x8b\x8c\x8d\x8e\x8f"
			"\x90\x91\x92\x93\x94\x95\x96\x97\x98\x99\x9a\x9b\x9c\x9d\x9e\x9f"
			"\xa0\xa1\xa2\xa3\xa4\xa5\xa6\xa7\xa8\xa9\xaa\xab\xac\xad\xae\xaf",
		.salt_size = 80,
		.info = "\xb0\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9\xba\xbb\xbc\xbd\xbe\xbf"
			"\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7\xc8\xc9\xca\xcb\xcc\xcd\xce\xcf"
			"\xd0\xd1\xd2\xd3\xd4\xd5\xd6\xd7\xd8\xd9\xda\xdb\xdc\xdd\xde\xdf"
			"\xe0\xe1\xe2\xe3\xe4\xe5\xe6\xe7\xe8\xe9\xea\xeb\xec\xed\xee\xef"
			"\xf0\xf1\xf2\xf3\xf4\xf5\xf6\xf7\xf8\xf9\xfa\xfb\xfc\xfd\xfe\xff",
		.info_size = 80,
		.prk  = "\xb3\x19\xf6\x83\x1d\xff\x93\x14\xef\xb6\x43\xba\xa2\x92\x63\xb3"
			"\x0e\x4a\x8d\x77\x9f\xe3\x1e\x9c\x90\x1e\xfd\x7d\xe7\x37\xc8\x5b"
			"\x62\xe6\x76\xd4\xdc\x87\xb0\x89\x5c\x6a\x7d\xc9\x7b\x52\xce\xbb",
		.prk_size = 48,
		.okm  = "\x48\x4c\xa0\x52\xb8\xcc\x72\x4f\xd1\xc4\xec\x64\xd5\x7b\x4e\x81"
			"\x8c\x7e\x25\xa8\xe0\xf4\x56\x9e\xd7\x2a\x6a\x05\xfe\x06\x49\xee"
			"\xbf\x69\xf8\xd5\xc8\x32\x85\x6b\xf4\xe4\xfb\xc1\x79\x67\xd5\x49"
			"\x75\x32\x4a\x94\x98\x7f\x7f\x41\x83\x58\x17\xd8\x99\x4f\xdb\xd6"
			"\xf4\xc0\x9c\x55\x00\xdc\xa2\x4a\x56\x22\x2f\xea\x53\xd8\x96\x7a"
			"\x8b\x2e",
		.okm_size = 82,
	}, {
		.test = "hkdf test with zero salt and info",
		.ikm  = "\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b"
			"\x0b\x0b\x0b\x0b\x0b\x0b",
		.ikm_size = 22,
		.salt = NULL,
		.salt_size = 0,
		.info = NULL,
		.info_size = 0,
		.prk  = "\x10\xe4\x0c\xf0\x72\xa4\xc5\x62\x6e\x43\xdd\x22\xc1\xcf\x72\x7d"
			"\x4b\xb1\x40\x97\x5c\x9a\xd0\xcb\xc8\xe4\x5b\x40\x06\x8f\x8f\x0b"
			"\xa5\x7c\xdb\x59\x8a\xf9\xdf\xa6\x96\x3a\x96\x89\x9a\xf0\x47\xe5",
		.prk_size = 48,
		.okm  = "\xc8\xc9\x6e\x71\x0f\x89\xb0\xd7\x99\x0b\xca\x68\xbc\xde\xc8\xcf"
			"\x85\x40\x62\xe5\x4c\x73\xa7\xab\xc7\x43\xfa\xde\x9b\x24\x2d\xaa"
			"\xcc\x1c\xea\x56\x70\x41\x5b\x52\x84\x9c",
		.okm_size = 42,
	}, {
		.test = "hkdf test with short input",
		.ikm  = "\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b",
		.ikm_size = 11,
		.salt = "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c",
		.salt_size = 13,
		.info = "\xf0\xf1\xf2\xf3\xf4\xf5\xf6\xf7\xf8\xf9",
		.info_size = 10,
		.prk  = "\x6d\x31\x69\x98\x28\x79\x80\x88\xb3\x59\xda\xd5\x0b\x8f\x01\xb0"
			"\x15\xf1\x7a\xa3\xbd\x4e\x27\xa6\xe9\xf8\x73\xb7\x15\x85\xca\x6a"
			"\x00\xd1\xf0\x82\x12\x8a\xdb\x3c\xf0\x53\x0b\x57\xc0\xf9\xac\x72",
		.prk_size = 48,
		.okm  = "\xfb\x7e\x67\x43\xeb\x42\xcd\xe9\x6f\x1b\x70\x77\x89\x52\xab\x75"
			"\x48\xca\xfe\x53\x24\x9f\x7f\xfe\x14\x97\xa1\x63\x5b\x20\x1f\xf1"
			"\x85\xb9\x3e\x95\x19\x92\xd8\x58\xf1\x1a",
		.okm_size = 42,
	}, {
		.test = "unsalted hkdf test with zero info",
		.ikm  = "\x0c\x0c\x0c\x0c\x0c\x0c\x0c\x0c\x0c\x0c\x0c\x0c\x0c\x0c\x0c\x0c"
			"\x0c\x0c\x0c\x0c\x0c\x0c",
		.ikm_size = 22,
		.salt = "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
			"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
			"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
		.salt_size = 48,
		.info = NULL,
		.info_size = 0,
		.prk  = "\x9d\x2d\xa5\x06\x6f\x05\xd1\x6c\x59\xfe\xdf\x6c\x5f\x32\xc7\x5e"
			"\xda\x9a\x47\xa7\x9c\x93\x6a\xa4\x4c\xb7\x63\xa8\xe2\x2f\xfb\xfc"
			"\xd8\xfe\x55\x43\x58\x53\x47\x21\x90\x39\xd1\x68\x28\x36\x33\xf5",
		.prk_size = 48,
		.okm  = "\x6a\xd7\xc7\x26\xc8\x40\x09\x54\x6a\x76\xe0\x54\x5d\xf2\x66\x78"
			"\x7e\x2b\x2c\xd6\xca\x43\x73\xa1\xf3\x14\x50\xa7\xbd\xf9\x48\x2b"
			"\xfa\xb8\x11\xf5\x54\x20\x0e\xad\x8f\x53",
		.okm_size = 42,
	}
};

static const struct hkdf_testvec hkdf_sha512_tv[] = {
	{
		.test = "basic hkdf test",
		.ikm  = "\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b"
			"\x0b\x0b\x0b\x0b\x0b\x0b",
		.ikm_size = 22,
		.salt = "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c",
		.salt_size = 13,
		.info = "\xf0\xf1\xf2\xf3\xf4\xf5\xf6\xf7\xf8\xf9",
		.info_size = 10,
		.prk  = "\x66\x57\x99\x82\x37\x37\xde\xd0\x4a\x88\xe4\x7e\x54\xa5\x89\x0b"
			"\xb2\xc3\xd2\x47\xc7\xa4\x25\x4a\x8e\x61\x35\x07\x23\x59\x0a\x26"
			"\xc3\x62\x38\x12\x7d\x86\x61\xb8\x8c\xf8\x0e\xf8\x02\xd5\x7e\x2f"
			"\x7c\xeb\xcf\x1e\x00\xe0\x83\x84\x8b\xe1\x99\x29\xc6\x1b\x42\x37",
		.prk_size = 64,
		.okm  = "\x83\x23\x90\x08\x6c\xda\x71\xfb\x47\x62\x5b\xb5\xce\xb1\x68\xe4"
			"\xc8\xe2\x6a\x1a\x16\xed\x34\xd9\xfc\x7f\xe9\x2c\x14\x81\x57\x93"
			"\x38\xda\x36\x2c\xb8\xd9\xf9\x25\xd7\xcb",
		.okm_size = 42,
	}, {
		.test = "hkdf test with long input",
		.ikm  = "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f"
			"\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"
			"\x20\x21\x22\x23\x24\x25\x26\x27\x28\x29\x2a\x2b\x2c\x2d\x2e\x2f"
			"\x30\x31\x32\x33\x34\x35\x36\x37\x38\x39\x3a\x3b\x3c\x3d\x3e\x3f"
			"\x40\x41\x42\x43\x44\x45\x46\x47\x48\x49\x4a\x4b\x4c\x4d\x4e\x4f",
		.ikm_size = 80,
		.salt = "\x60\x61\x62\x63\x64\x65\x66\x67\x68\x69\x6a\x6b\x6c\x6d\x6e\x6f"
			"\x70\x71\x72\x73\x74\x75\x76\x77\x78\x79\x7a\x7b\x7c\x7d\x7e\x7f"
			"\x80\x81\x82\x83\x84\x85\x86\x87\x88\x89\x8a\x8b\x8c\x8d\x8e\x8f"
			"\x90\x91\x92\x93\x94\x95\x96\x97\x98\x99\x9a\x9b\x9c\x9d\x9e\x9f"
			"\xa0\xa1\xa2\xa3\xa4\xa5\xa6\xa7\xa8\xa9\xaa\xab\xac\xad\xae\xaf",
		.salt_size = 80,
		.info = "\xb0\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9\xba\xbb\xbc\xbd\xbe\xbf"
			"\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7\xc8\xc9\xca\xcb\xcc\xcd\xce\xcf"
			"\xd0\xd1\xd2\xd3\xd4\xd5\xd6\xd7\xd8\xd9\xda\xdb\xdc\xdd\xde\xdf"
			"\xe0\xe1\xe2\xe3\xe4\xe5\xe6\xe7\xe8\xe9\xea\xeb\xec\xed\xee\xef"
			"\xf0\xf1\xf2\xf3\xf4\xf5\xf6\xf7\xf8\xf9\xfa\xfb\xfc\xfd\xfe\xff",
		.info_size = 80,
		.prk  = "\x35\x67\x25\x42\x90\x7d\x4e\x14\x2c\x00\xe8\x44\x99\xe7\x4e\x1d"
			"\xe0\x8b\xe8\x65\x35\xf9\x24\xe0\x22\x80\x4a\xd7\x75\xdd\xe2\x7e"
			"\xc8\x6c\xd1\xe5\xb7\xd1\x78\xc7\x44\x89\xbd\xbe\xb3\x07\x12\xbe"
			"\xb8\x2d\x4f\x97\x41\x6c\x5a\x94\xea\x81\xeb\xdf\x3e\x62\x9e\x4a",
		.prk_size = 64,
		.okm  = "\xce\x6c\x97\x19\x28\x05\xb3\x46\xe6\x16\x1e\x82\x1e\xd1\x65\x67"
			"\x3b\x84\xf4\x00\xa2\xb5\x14\xb2\xfe\x23\xd8\x4c\xd1\x89\xdd\xf1"
			"\xb6\x95\xb4\x8c\xbd\x1c\x83\x88\x44\x11\x37\xb3\xce\x28\xf1\x6a"
			"\xa6\x4b\xa3\x3b\xa4\x66\xb2\x4d\xf6\xcf\xcb\x02\x1e\xcf\xf2\x35"
			"\xf6\xa2\x05\x6c\xe3\xaf\x1d\xe4\x4d\x57\x20\x97\xa8\x50\x5d\x9e"
			"\x7a\x93",
		.okm_size = 82,
	}, {
		.test = "hkdf test with zero salt and info",
		.ikm  = "\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b"
			"\x0b\x0b\x0b\x0b\x0b\x0b",
		.ikm_size = 22,
		.salt = NULL,
		.salt_size = 0,
		.info = NULL,
		.info_size = 0,
		.prk  = "\xfd\x20\x0c\x49\x87\xac\x49\x13\x13\xbd\x4a\x2a\x13\x28\x71\x21"
			"\x24\x72\x39\xe1\x1c\x9e\xf8\x28\x02\x04\x4b\x66\xef\x35\x7e\x5b"
			"\x19\x44\x98\xd0\x68\x26\x11\x38\x23\x48\x57\x2a\x7b\x16\x11\xde"
			"\x54\x76\x40\x94\x28\x63\x20\x57\x8a\x86\x3f\x36\x56\x2b\x0d\xf6",
		.prk_size = 64,
		.okm  = "\xf5\xfa\x02\xb1\x82\x98\xa7\x2a\x8c\x23\x89\x8a\x87\x03\x47\x2c"
			"\x6e\xb1\x79\xdc\x20\x4c\x03\x42\x5c\x97\x0e\x3b\x16\x4b\xf9\x0f"
			"\xff\x22\xd0\x48\x36\xd0\xe2\x34\x3b\xac",
		.okm_size = 42,
	}, {
		.test = "hkdf test with short input",
		.ikm  = "\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b\x0b",
		.ikm_size = 11,
		.salt = "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c",
		.salt_size = 13,
		.info = "\xf0\xf1\xf2\xf3\xf4\xf5\xf6\xf7\xf8\xf9",
		.info_size = 10,
		.prk  = "\x67\x40\x9c\x9c\xac\x28\xb5\x2e\xe9\xfa\xd9\x1c\x2f\xda\x99\x9f"
			"\x7c\xa2\x2e\x34\x34\xf0\xae\x77\x28\x63\x83\x65\x68\xad\x6a\x7f"
			"\x10\xcf\x11\x3b\xfd\xdd\x56\x01\x29\xa5\x94\xa8\xf5\x23\x85\xc2"
			"\xd6\x61\xd7\x85\xd2\x9c\xe9\x3a\x11\x40\x0c\x92\x06\x83\x18\x1d",
		.prk_size = 64,
		.okm  = "\x74\x13\xe8\x99\x7e\x02\x06\x10\xfb\xf6\x82\x3f\x2c\xe1\x4b\xff"
			"\x01\x87\x5d\xb1\xca\x55\xf6\x8c\xfc\xf3\x95\x4d\xc8\xaf\xf5\x35"
			"\x59\xbd\x5e\x30\x28\xb0\x80\xf7\xc0\x68",
		.okm_size = 42,
	}, {
		.test = "unsalted hkdf test with zero info",
		.ikm  = "\x0c\x0c\x0c\x0c\x0c\x0c\x0c\x0c\x0c\x0c\x0c\x0c\x0c\x0c\x0c\x0c"
			"\x0c\x0c\x0c\x0c\x0c\x0c",
		.ikm_size = 22,
		.salt = "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
			"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
			"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
			"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
		.salt_size = 64,
		.info = NULL,
		.info_size = 0,
		.prk  = "\x53\x46\xb3\x76\xbf\x3a\xa9\xf8\x4f\x8f\x6e\xd5\xb1\xc4\xf4\x89"
			"\x17\x2e\x24\x4d\xac\x30\x3d\x12\xf6\x8e\xcc\x76\x6e\xa6\x00\xaa"
			"\x88\x49\x5e\x7f\xb6\x05\x80\x31\x22\xfa\x13\x69\x24\xa8\x40\xb1"
			"\xf0\x71\x9d\x2d\x5f\x68\xe2\x9b\x24\x22\x99\xd7\x58\xed\x68\x0c",
		.prk_size = 64,
		.okm  = "\x14\x07\xd4\x60\x13\xd9\x8b\xc6\xde\xce\xfc\xfe\xe5\x5f\x0f\x90"
			"\xb0\xc7\xf6\x3d\x68\xeb\x1a\x80\xea\xf0\x7e\x95\x3c\xfc\x0a\x3a"
			"\x52\x40\xa1\x55\xd6\xe4\xda\xa9\x65\xbb",
		.okm_size = 42,
	}
};

static int hkdf_test(const char *shash, const struct hkdf_testvec *tv)
{	struct crypto_shash *tfm = NULL;
	u8 *prk = NULL, *okm = NULL;
	unsigned int prk_size;
	const char *driver;
	int err;

	tfm = crypto_alloc_shash(shash, 0, 0);
	if (IS_ERR(tfm)) {
		pr_err("%s(%s): failed to allocate transform: %ld\n",
		       tv->test, shash, PTR_ERR(tfm));
		return PTR_ERR(tfm);
	}
	driver = crypto_shash_driver_name(tfm);

	prk_size = crypto_shash_digestsize(tfm);
	prk = kzalloc(prk_size, GFP_KERNEL);
	if (!prk) {
		err = -ENOMEM;
		goto out_free;
	}

	if (tv->prk_size != prk_size) {
		pr_err("%s(%s): prk size mismatch (vec %u, digest %u\n",
		       tv->test, driver, tv->prk_size, prk_size);
		err = -EINVAL;
		goto out_free;
	}

	err = hkdf_extract(tfm, tv->ikm, tv->ikm_size,
			   tv->salt, tv->salt_size, prk);
	if (err) {
		pr_err("%s(%s): hkdf_extract failed with %d\n",
		       tv->test, driver, err);
		goto out_free;
	}

	if (memcmp(prk, tv->prk, tv->prk_size)) {
		pr_err("%s(%s): hkdf_extract prk mismatch\n",
		       tv->test, driver);
		print_hex_dump(KERN_ERR, "prk: ", DUMP_PREFIX_NONE,
			       16, 1, prk, tv->prk_size, false);
		err = -EINVAL;
		goto out_free;
	}

	okm = kzalloc(tv->okm_size, GFP_KERNEL);
	if (!okm) {
		err = -ENOMEM;
		goto out_free;
	}

	err = crypto_shash_setkey(tfm, tv->prk, tv->prk_size);
	if (err) {
		pr_err("%s(%s): failed to set prk, error %d\n",
		       tv->test, driver, err);
		goto out_free;
	}

	err = hkdf_expand(tfm, tv->info, tv->info_size,
			  okm, tv->okm_size);
	if (err) {
		pr_err("%s(%s): hkdf_expand() failed with %d\n",
		       tv->test, driver, err);
	} else if (memcmp(okm, tv->okm, tv->okm_size)) {
		pr_err("%s(%s): hkdf_expand() okm mismatch\n",
		       tv->test, driver);
		print_hex_dump(KERN_ERR, "okm: ", DUMP_PREFIX_NONE,
			       16, 1, okm, tv->okm_size, false);
		err = -EINVAL;
	}
out_free:
	kfree(okm);
	kfree(prk);
	crypto_free_shash(tfm);
	return err;
}

static int __init crypto_hkdf_module_init(void)
{
	int ret = 0, i;

	if (!IS_ENABLED(CONFIG_CRYPTO_SELFTESTS))
		return 0;

	for (i = 0; i < ARRAY_SIZE(hkdf_sha256_tv); i++) {
		ret = hkdf_test("hmac(sha256)", &hkdf_sha256_tv[i]);
		if (ret)
			return ret;
	}
	for (i = 0; i < ARRAY_SIZE(hkdf_sha384_tv); i++) {
		ret = hkdf_test("hmac(sha384)", &hkdf_sha384_tv[i]);
		if (ret)
			return ret;
	}
	for (i = 0; i < ARRAY_SIZE(hkdf_sha512_tv); i++) {
		ret = hkdf_test("hmac(sha512)", &hkdf_sha512_tv[i]);
		if (ret)
			return ret;
	}
	return 0;
}

static void __exit crypto_hkdf_module_exit(void) {}

late_initcall(crypto_hkdf_module_init);
module_exit(crypto_hkdf_module_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("HMAC-based Key Derivation Function (HKDF)");