From patchwork Wed Jun 1 07:18:10 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nathan Huckleberry X-Patchwork-Id: 12866442 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B6A04C433EF for ; Wed, 1 Jun 2022 07:18:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350219AbiFAHSj (ORCPT ); Wed, 1 Jun 2022 03:18:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35692 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350242AbiFAHSi (ORCPT ); Wed, 1 Jun 2022 03:18:38 -0400 Received: from mail-vk1-xa49.google.com (mail-vk1-xa49.google.com [IPv6:2607:f8b0:4864:20::a49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B67253A1A1 for ; Wed, 1 Jun 2022 00:18:36 -0700 (PDT) Received: by mail-vk1-xa49.google.com with SMTP id m71-20020a1fa34a000000b003572cab1489so147032vke.4 for ; Wed, 01 Jun 2022 00:18:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=xCCB5zDb/K/3E5aM9WYFTX2Uc7twxEaR4jU1CSA3ieg=; b=a5978nP5GoeS1S+hck7z9bqYCHpvjOpGtmnrSYIbIhGM/2YCF0Zx5N7M0d2YY/U3+O +5WUYVswCKEVkxNbgPR0SbqPiFOGkzKp0AStLiINUNIzOnsRuJ+whtKNjGqZzYRB67rl atxY0d/5PaaETx0rWatMCSHcTvCL7OJVPm+FT0svsnLhjjXuyN/MqgCVXfCL7KVUrgob lLzv4lOpJEkGSq4fhYhvamwseG2eOLS+0USdH9HWatHQSPWcny8LrFIElNNmBNdkJMbx i5QE/uFblj1Glfsi/CjIfpEeJW5dfAaogp90OXD5b5n/hPzGJhOtDMV+Lxfs5pGZUxa/ ZXBA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=xCCB5zDb/K/3E5aM9WYFTX2Uc7twxEaR4jU1CSA3ieg=; b=7xht1qIEC0RfQAmkrUATI9RPIkOIl7PJoksZ5i2tm0dGTMxnNijflZ8KUflaNbQ4L3 LMil3cXIgfYU3aJV15fotJ3ZCTpG4mYn3a4sl5F1ay6fetWB2F/ijWzlSS0GQMfOOb8Y 9uG2xMBUW482RmNTaUADYEWb5HrsHYA9RvckAIy3gjhqfAbBiQjtTh85n1FNrqytKbjl 61wyJhosgd/vZchsiZFJB/jmwvysbh9i5TePTGhuCiB7gDNsKWlm2LCkuO4N2rTFWSy7 b7L3QACFnYpGlH7jHmoesJ9QiTWwt3fRmiZ6KyUbUYMDbVV5s+0Uipb8YsYBTzlNxkNe kINA== X-Gm-Message-State: AOAM532YL8NHpIFpaSb4eSUddxeShahUNGJv8d35Q7K+9YvFAnfYTnub E4M3bwHICa+7q1HFXnnTuepUHYPgLA== X-Google-Smtp-Source: ABdhPJwZBRqh+tN7Kq0a47YttBg6oS3iPgYOWUZQCz4SDgtTqFsIzfOdxFaa3xj1rmtaTSXvlCePkwbHEw== X-Received: from nhuck.c.googlers.com ([fda3:e722:ac3:cc00:14:4d90:c0a8:39cc]) (user=nhuck job=sendgmr) by 2002:ab0:3492:0:b0:368:b577:bfd with SMTP id c18-20020ab03492000000b00368b5770bfdmr22391896uar.110.1654067915741; Wed, 01 Jun 2022 00:18:35 -0700 (PDT) Date: Wed, 1 Jun 2022 00:18:10 -0700 In-Reply-To: <20220601071811.1353635-1-nhuck@google.com> Message-Id: <20220601071811.1353635-2-nhuck@google.com> Mime-Version: 1.0 References: <20220601071811.1353635-1-nhuck@google.com> X-Mailer: git-send-email 2.36.1.255.ge46751e96f-goog Subject: [RFC PATCH v4 1/2] fscrypt-crypt-util: add HCTR2 implementation From: Nathan Huckleberry To: fstests@vger.kernel.org, linux-fscrypt@vger.kernel.org Cc: Eric Biggers , Sami Tolvanen , Nathan Huckleberry Precedence: bulk List-ID: X-Mailing-List: linux-fscrypt@vger.kernel.org This patch adds an implementation of HCTR2 to the fscrypt testing utility. More information on HCTR2 can be found here: "Length-preserving encryption with HCTR2": https://ia.cr/2021/1441 Signed-off-by: Nathan Huckleberry --- common/encrypt | 2 + src/fscrypt-crypt-util.c | 341 ++++++++++++++++++++++++++++++++------- 2 files changed, 286 insertions(+), 57 deletions(-) diff --git a/common/encrypt b/common/encrypt index f90c4ef0..937bb914 100644 --- a/common/encrypt +++ b/common/encrypt @@ -767,6 +767,7 @@ FSCRYPT_MODE_AES_256_CTS=4 FSCRYPT_MODE_AES_128_CBC=5 FSCRYPT_MODE_AES_128_CTS=6 FSCRYPT_MODE_ADIANTUM=9 +FSCRYPT_MODE_AES_256_HCTR2=10 FSCRYPT_POLICY_FLAG_DIRECT_KEY=0x04 FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64=0x08 @@ -785,6 +786,7 @@ _fscrypt_mode_name_to_num() AES-128-CBC-ESSIV) echo $FSCRYPT_MODE_AES_128_CBC ;; AES-128-CTS-CBC) echo $FSCRYPT_MODE_AES_128_CTS ;; Adiantum) echo $FSCRYPT_MODE_ADIANTUM ;; + AES-256-HCTR2) echo $FSCRYPT_MODE_AES_256_HCTR2 ;; *) _fail "Unknown fscrypt mode: $name" ;; esac } diff --git a/src/fscrypt-crypt-util.c b/src/fscrypt-crypt-util.c index 03cc3c4a..6e91577e 100644 --- a/src/fscrypt-crypt-util.c +++ b/src/fscrypt-crypt-util.c @@ -37,7 +37,8 @@ /* * Define to enable the tests of the crypto code in this file. If enabled, you * must link this program with OpenSSL (-lcrypto) v1.1.0 or later, and your - * kernel needs CONFIG_CRYPTO_USER_API_SKCIPHER=y and CONFIG_CRYPTO_ADIANTUM=y. + * kernel needs CONFIG_CRYPTO_USER_API_SKCIPHER=y, CONFIG_CRYPTO_ADIANTUM=y, and + * CONFIG_CRYPTO_HCTR2=y. */ #undef ENABLE_ALG_TESTS @@ -54,7 +55,8 @@ static void usage(FILE *fp) "resulting ciphertext (or plaintext) to stdout.\n" "\n" "CIPHER can be AES-256-XTS, AES-256-CTS-CBC, AES-128-CBC-ESSIV, AES-128-CTS-CBC,\n" -"or Adiantum. MASTER_KEY must be a hex string long enough for the cipher.\n" +"Adiantum, or AES-256-HCTR2. MASTER_KEY must be a hex string long enough for\n" +"the cipher.\n" "\n" "WARNING: this program is only meant for testing, not for \"real\" use!\n" "\n" @@ -268,7 +270,59 @@ static void rand_bytes(u8 *buf, size_t count) while (count--) *buf++ = rand(); } -#endif + +#include +#include +#define SOL_ALG 279 +static void af_alg_crypt(int algfd, int op, const u8 *key, size_t keylen, + const u8 *iv, size_t ivlen, + const u8 *src, u8 *dst, size_t datalen) +{ + size_t controllen = CMSG_SPACE(sizeof(int)) + + CMSG_SPACE(sizeof(struct af_alg_iv) + ivlen); + u8 *control = xmalloc(controllen); + struct iovec iov = { .iov_base = (u8 *)src, .iov_len = datalen }; + struct msghdr msg = { + .msg_iov = &iov, + .msg_iovlen = 1, + .msg_control = control, + .msg_controllen = controllen, + }; + struct cmsghdr *cmsg; + struct af_alg_iv *algiv; + int reqfd; + + memset(control, 0, controllen); + + cmsg = CMSG_FIRSTHDR(&msg); + cmsg->cmsg_len = CMSG_LEN(sizeof(int)); + cmsg->cmsg_level = SOL_ALG; + cmsg->cmsg_type = ALG_SET_OP; + *(int *)CMSG_DATA(cmsg) = op; + + cmsg = CMSG_NXTHDR(&msg, cmsg); + cmsg->cmsg_len = CMSG_LEN(sizeof(struct af_alg_iv) + ivlen); + cmsg->cmsg_level = SOL_ALG; + cmsg->cmsg_type = ALG_SET_IV; + algiv = (struct af_alg_iv *)CMSG_DATA(cmsg); + algiv->ivlen = ivlen; + memcpy(algiv->iv, iv, ivlen); + + if (setsockopt(algfd, SOL_ALG, ALG_SET_KEY, key, keylen) != 0) + die_errno("can't set key on AF_ALG socket"); + + reqfd = accept(algfd, NULL, NULL); + if (reqfd < 0) + die_errno("can't accept() AF_ALG socket"); + if (sendmsg(reqfd, &msg, 0) != datalen) + die_errno("can't sendmsg() AF_ALG request socket"); + if (xread(reqfd, dst, datalen) != datalen) + die("short read from AF_ALG request socket"); + close(reqfd); + + free(control); +} +#endif /* ENABLE_ALG_TESTS */ /*----------------------------------------------------------------------------* * Finite field arithmetic * @@ -293,7 +347,7 @@ typedef struct { } ble128; /* Multiply a GF(2^128) element by the polynomial 'x' */ -static inline void gf2_128_mul_x(ble128 *t) +static inline void gf2_128_mul_x_xts(ble128 *t) { u64 lo = le64_to_cpu(t->lo); u64 hi = le64_to_cpu(t->hi); @@ -302,6 +356,38 @@ static inline void gf2_128_mul_x(ble128 *t) t->lo = cpu_to_le64((lo << 1) ^ ((hi & (1ULL << 63)) ? 0x87 : 0)); } +static inline void gf2_128_mul_x_polyval(ble128 *t) +{ + u64 lo = le64_to_cpu(t->lo); + u64 hi = le64_to_cpu(t->hi); + u64 lo_reducer = (hi & (1ULL << 63)) ? 1 : 0; + u64 hi_reducer = (hi & (1ULL << 63)) ? 0xc2ULL << 56 : 0; + + t->hi = cpu_to_le64(((hi << 1) | (lo >> 63)) ^ hi_reducer); + t->lo = cpu_to_le64((lo << 1) ^ lo_reducer); +} + +void gf2_128_mul_polyval(ble128 *r, const ble128 *b) +{ + int i; + ble128 p; + u64 lo = le64_to_cpu(b->lo); + u64 hi = le64_to_cpu(b->hi); + + memset(&p, 0, sizeof(p)); + for (i = 0; i < 64; i++) { + if (lo & (1ULL << i)) + xor((u8 *)&p, (u8 *)&p, (u8 *)r, sizeof(p)); + gf2_128_mul_x_polyval(r); + } + for (i = 0; i < 64; i++) { + if (hi & (1ULL << i)) + xor((u8 *)&p, (u8 *)&p, (u8 *)r, sizeof(p)); + gf2_128_mul_x_polyval(r); + } + *r = p; +} + /*----------------------------------------------------------------------------* * Group arithmetic * *----------------------------------------------------------------------------*/ @@ -901,6 +987,41 @@ static void test_hkdf_sha512(void) } #endif /* ENABLE_ALG_TESTS */ +/*----------------------------------------------------------------------------* + * POLYVAL * + *----------------------------------------------------------------------------*/ + +#define POLYVAL_KEY_SIZE 16 +#define POLYVAL_BLOCK_SIZE 16 + +static void polyval_update(const u8 key[POLYVAL_KEY_SIZE], + const u8 *msg, size_t msglen, + u8 accumulator[POLYVAL_BLOCK_SIZE]) +{ + ble128 h; + ble128 aligned_accumulator; + size_t chunk_size; + // x^{-128} = x^127 + x^124 + x^121 + x^114 + 1 + static const ble128 inv128 = { + cpu_to_le64(1), + cpu_to_le64(0x9204ULL << 48) + }; + + memcpy(&h, key, POLYVAL_BLOCK_SIZE); + memcpy(&aligned_accumulator, accumulator, POLYVAL_BLOCK_SIZE); + gf2_128_mul_polyval(&h, &inv128); + + while (msglen > 0) { + chunk_size = MIN(POLYVAL_BLOCK_SIZE, msglen); + xor((u8 *)&aligned_accumulator, (u8 *)&aligned_accumulator, msg, + chunk_size); + gf2_128_mul_polyval(&aligned_accumulator, &h); + msg += chunk_size; + msglen -= chunk_size; + } + memcpy(accumulator, &aligned_accumulator, POLYVAL_BLOCK_SIZE); +} + /*----------------------------------------------------------------------------* * AES encryption modes * *----------------------------------------------------------------------------*/ @@ -924,7 +1045,7 @@ static void aes_256_xts_crypt(const u8 key[2 * AES_256_KEY_SIZE], else aes_encrypt(&cipher_key, &dst[i], &dst[i]); xor(&dst[i], &dst[i], (const u8 *)&t, AES_BLOCK_SIZE); - gf2_128_mul_x(&t); + gf2_128_mul_x_xts(&t); } } @@ -1173,6 +1294,157 @@ static void aes_128_cts_cbc_decrypt(const u8 key[AES_128_KEY_SIZE], aes_cts_cbc_decrypt(key, AES_128_KEY_SIZE, iv, src, dst, nbytes); } +static void aes_256_xctr_crypt(const u8 key[AES_256_KEY_SIZE], + const u8 iv[AES_BLOCK_SIZE], const u8 *src, + u8 *dst, size_t nbytes) +{ + struct aes_key k; + union { + u8 bytes[AES_BLOCK_SIZE]; + __le64 ctr; + } blk; + size_t i; + + aes_setkey(&k, key, AES_256_KEY_SIZE); + + for (i = 0; i < nbytes; i += AES_BLOCK_SIZE) { + memcpy(blk.bytes, iv, AES_BLOCK_SIZE); + blk.ctr ^= cpu_to_le64((i / AES_BLOCK_SIZE) + 1); + aes_encrypt(&k, blk.bytes, blk.bytes); + xor(&dst[i], blk.bytes, &src[i], MIN(AES_BLOCK_SIZE, nbytes - i)); + } +} + +#define HCTR2_IV_SIZE 32 +static void hctr2_hash_iv(const u8 hbar[POLYVAL_KEY_SIZE], + const u8 iv[HCTR2_IV_SIZE], size_t msglen, + u8 digest[POLYVAL_BLOCK_SIZE]) +{ + le128 tweaklen_blk = { + .lo = cpu_to_le64(HCTR2_IV_SIZE * 8 * 2 + 2 + + (msglen % AES_BLOCK_SIZE != 0)) + }; + + memset(digest, 0, POLYVAL_BLOCK_SIZE); + polyval_update(hbar, (u8 *)&tweaklen_blk, POLYVAL_BLOCK_SIZE, digest); + polyval_update(hbar, iv, HCTR2_IV_SIZE, digest); +} + +static void hctr2_hash_message(const u8 hbar[POLYVAL_KEY_SIZE], + const u8 *msg, size_t msglen, + u8 digest[POLYVAL_BLOCK_SIZE]) +{ + size_t remainder = msglen % AES_BLOCK_SIZE; + u8 padded_block[POLYVAL_BLOCK_SIZE] = {0}; + + polyval_update(hbar, msg, msglen - remainder, digest); + if (remainder) { + memcpy(padded_block, &msg[msglen - remainder], remainder); + padded_block[remainder] = 1; + polyval_update(hbar, padded_block, POLYVAL_BLOCK_SIZE, digest); + } +} + +static void aes_256_hctr2_crypt(const u8 key[AES_256_KEY_SIZE], + const u8 iv[HCTR2_IV_SIZE], const u8 *src, + u8 *dst, size_t nbytes, bool decrypting) +{ + struct aes_key k; + u8 hbar[AES_BLOCK_SIZE] = {0}; + u8 L[AES_BLOCK_SIZE] = {1}; + size_t bulk_bytes = nbytes - AES_BLOCK_SIZE; + u8 digest[POLYVAL_BLOCK_SIZE]; + const u8 *M = src; + const u8 *N = src + AES_BLOCK_SIZE; + u8 MM[AES_BLOCK_SIZE]; + u8 UU[AES_BLOCK_SIZE]; + u8 S[AES_BLOCK_SIZE]; + u8 *U = dst; + u8 *V = dst + AES_BLOCK_SIZE; + + ASSERT(nbytes >= AES_BLOCK_SIZE); + aes_setkey(&k, key, AES_256_KEY_SIZE); + + aes_encrypt(&k, hbar, hbar); + aes_encrypt(&k, L, L); + + hctr2_hash_iv(hbar, iv, bulk_bytes, digest); + hctr2_hash_message(hbar, N, bulk_bytes, digest); + + xor(MM, M, digest, AES_BLOCK_SIZE); + + if (decrypting) + aes_decrypt(&k, MM, UU); + else + aes_encrypt(&k, MM, UU); + + xor(S, MM, UU, AES_BLOCK_SIZE); + xor(S, L, S, AES_BLOCK_SIZE); + + aes_256_xctr_crypt(key, S, N, V, bulk_bytes); + + hctr2_hash_iv(hbar, iv, bulk_bytes, digest); + hctr2_hash_message(hbar, V, bulk_bytes, digest); + + xor(U, UU, digest, AES_BLOCK_SIZE); +} + +static void aes_256_hctr2_encrypt(const u8 key[AES_256_KEY_SIZE], + const u8 iv[HCTR2_IV_SIZE], const u8 *src, + u8 *dst, size_t nbytes) +{ + aes_256_hctr2_crypt(key, iv, src, dst, nbytes, false); +} + +static void aes_256_hctr2_decrypt(const u8 key[AES_256_KEY_SIZE], + const u8 iv[HCTR2_IV_SIZE], const u8 *src, + u8 *dst, size_t nbytes) +{ + aes_256_hctr2_crypt(key, iv, src, dst, nbytes, true); +} + +#ifdef ENABLE_ALG_TESTS +#include +#include +static void test_aes_256_hctr2(void) +{ + int algfd = socket(AF_ALG, SOCK_SEQPACKET, 0); + struct sockaddr_alg addr = { + .salg_type = "skcipher", + .salg_name = "hctr2(aes)", + }; + unsigned long num_tests = NUM_ALG_TEST_ITERATIONS; + + if (algfd < 0) + die_errno("can't create AF_ALG socket"); + if (bind(algfd, (struct sockaddr *)&addr, sizeof(addr)) != 0) + die_errno("can't bind AF_ALG socket to HCTR2 algorithm"); + + while (num_tests--) { + u8 key[AES_256_KEY_SIZE]; + u8 iv[HCTR2_IV_SIZE]; + u8 ptext[4096]; + u8 ctext[sizeof(ptext)]; + u8 ref_ctext[sizeof(ptext)]; + u8 decrypted[sizeof(ptext)]; + const size_t datalen = 16 + (rand() % (sizeof(ptext) - 15)); + + rand_bytes(key, sizeof(key)); + rand_bytes(iv, sizeof(iv)); + rand_bytes(ptext, datalen); + + aes_256_hctr2_encrypt(key, iv, ptext, ctext, datalen); + af_alg_crypt(algfd, ALG_OP_ENCRYPT, key, sizeof(key), + iv, sizeof(iv), ptext, ref_ctext, datalen); + ASSERT(memcmp(ctext, ref_ctext, datalen) == 0); + + aes_256_hctr2_decrypt(key, iv, ctext, decrypted, datalen); + ASSERT(memcmp(ptext, decrypted, datalen) == 0); + } + close(algfd); +} +#endif /* ENABLE_ALG_TESTS */ + /*----------------------------------------------------------------------------* * XChaCha12 stream cipher * *----------------------------------------------------------------------------*/ @@ -1500,58 +1772,6 @@ static void adiantum_decrypt(const u8 key[ADIANTUM_KEY_SIZE], } #ifdef ENABLE_ALG_TESTS -#include -#include -#define SOL_ALG 279 -static void af_alg_crypt(int algfd, int op, const u8 *key, size_t keylen, - const u8 *iv, size_t ivlen, - const u8 *src, u8 *dst, size_t datalen) -{ - size_t controllen = CMSG_SPACE(sizeof(int)) + - CMSG_SPACE(sizeof(struct af_alg_iv) + ivlen); - u8 *control = xmalloc(controllen); - struct iovec iov = { .iov_base = (u8 *)src, .iov_len = datalen }; - struct msghdr msg = { - .msg_iov = &iov, - .msg_iovlen = 1, - .msg_control = control, - .msg_controllen = controllen, - }; - struct cmsghdr *cmsg; - struct af_alg_iv *algiv; - int reqfd; - - memset(control, 0, controllen); - - cmsg = CMSG_FIRSTHDR(&msg); - cmsg->cmsg_len = CMSG_LEN(sizeof(int)); - cmsg->cmsg_level = SOL_ALG; - cmsg->cmsg_type = ALG_SET_OP; - *(int *)CMSG_DATA(cmsg) = op; - - cmsg = CMSG_NXTHDR(&msg, cmsg); - cmsg->cmsg_len = CMSG_LEN(sizeof(struct af_alg_iv) + ivlen); - cmsg->cmsg_level = SOL_ALG; - cmsg->cmsg_type = ALG_SET_IV; - algiv = (struct af_alg_iv *)CMSG_DATA(cmsg); - algiv->ivlen = ivlen; - memcpy(algiv->iv, iv, ivlen); - - if (setsockopt(algfd, SOL_ALG, ALG_SET_KEY, key, keylen) != 0) - die_errno("can't set key on AF_ALG socket"); - - reqfd = accept(algfd, NULL, NULL); - if (reqfd < 0) - die_errno("can't accept() AF_ALG socket"); - if (sendmsg(reqfd, &msg, 0) != datalen) - die_errno("can't sendmsg() AF_ALG request socket"); - if (xread(reqfd, dst, datalen) != datalen) - die("short read from AF_ALG request socket"); - close(reqfd); - - free(control); -} - static void test_adiantum(void) { int algfd = socket(AF_ALG, SOCK_SEQPACKET, 0); @@ -1675,6 +1895,12 @@ static const struct fscrypt_cipher { .decrypt = aes_128_cts_cbc_decrypt, .keysize = AES_128_KEY_SIZE, .min_input_size = AES_BLOCK_SIZE, + }, { + .name = "AES-256-HCTR2", + .encrypt = aes_256_hctr2_encrypt, + .decrypt = aes_256_hctr2_decrypt, + .keysize = AES_256_KEY_SIZE, + .min_input_size = AES_BLOCK_SIZE, }, { .name = "Adiantum", .encrypt = adiantum_encrypt, @@ -1980,6 +2206,7 @@ int main(int argc, char *argv[]) test_aes_256_xts(); test_aes_256_cts_cbc(); test_adiantum(); + test_aes_256_hctr2(); #endif while ((c = getopt_long(argc, argv, "", longopts, NULL)) != -1) {