From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 37EC5FA372C for ; Fri, 8 Nov 2019 12:24:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F0CEE224BF for ; Fri, 8 Nov 2019 12:24:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573215882; bh=4d4KL39L7Up/JNtOOwcIvoB4IqMrwplxJU7JWX17vdg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=PKAMzmJPHwIhg9zyhAGIVrcd4g/2AMWDf5IltDdSbClY+LFucdko4R618ihPsAAQj sN91kLlTaAUGYXmp8361dnF5g+Lau+bSzvltbTBNPXMqUJ9e98zfDBqT+WlEUB7j2Z 3PV9tEw3V/Aa7lKbWs4elruQCMEtxv+aeG+pdMc0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732559AbfKHMYl (ORCPT ); Fri, 8 Nov 2019 07:24:41 -0500 Received: from mail.kernel.org ([198.145.29.99]:38984 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732466AbfKHMYl (ORCPT ); Fri, 8 Nov 2019 07:24:41 -0500 Received: from localhost.localdomain (laubervilliers-657-1-83-120.w92-154.abo.wanadoo.fr [92.154.90.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 618E3224BE; Fri, 8 Nov 2019 12:24:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573215879; bh=4d4KL39L7Up/JNtOOwcIvoB4IqMrwplxJU7JWX17vdg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uFMFI3gK+Z3QUT69lVfZcezQAOTl+4sghxIPW9n9RqdpSc6xHc2Fhb71E0VUtANFi 1An2MYiT+YtfRAIEEQr6N6C2nLPdPCGC/A9yGvKIWbVzPJNCz0Ujatc3NJKQw2+vaI WaoCd7Ccir8RNSSmIO0KOpusGvS8XBXI/saiQJos= From: Ard Biesheuvel To: linux-crypto@vger.kernel.org Cc: Ard Biesheuvel , Herbert Xu , David Miller , "Jason A . Donenfeld" , Samuel Neves , Arnd Bergmann , Eric Biggers , Andy Lutomirski , Martin Willi , Rene van Dorst , David Sterba Subject: [PATCH v5 34/34] crypto: lib/chacha20poly1305 - reimplement crypt_from_sg() routine Date: Fri, 8 Nov 2019 13:22:40 +0100 Message-Id: <20191108122240.28479-35-ardb@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191108122240.28479-1-ardb@kernel.org> References: <20191108122240.28479-1-ardb@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org Reimplement the library routines to perform chacha20poly1305 en/decryption on scatterlists, without [ab]using the [deprecated] blkcipher interface, which is rather heavyweight and does things we don't really need. Instead, we use the sg_miter API in a novel and clever way, to iterate over the scatterlist in-place (i.e., source == destination, which is the only way this library is expected to be used). That way, we don't have to iterate over two scatterlists in parallel. Another optimization is that, instead of relying on the blkcipher walker to present the input in suitable chunks, we recognize that ChaCha is a streamcipher, and so we can simply deal with partial blocks by keeping a block of cipherstream on the stack and use crypto_xor() to mix it with the in/output. Finally, we omit the scatterwalk_and_copy() call if the last element of the scatterlist covers the MAC as well (which is the common case), avoiding the need to walk the scatterlist and kmap() the page twice. Signed-off-by: Ard Biesheuvel --- include/crypto/chacha20poly1305.h | 11 ++ lib/crypto/chacha20poly1305-selftest.c | 45 ++++++ lib/crypto/chacha20poly1305.c | 150 ++++++++++++++++++++ 3 files changed, 206 insertions(+) diff --git a/include/crypto/chacha20poly1305.h b/include/crypto/chacha20poly1305.h index ad3b1de58df8..234ee28078ef 100644 --- a/include/crypto/chacha20poly1305.h +++ b/include/crypto/chacha20poly1305.h @@ -7,6 +7,7 @@ #define __CHACHA20POLY1305_H #include +#include enum chacha20poly1305_lengths { XCHACHA20POLY1305_NONCE_SIZE = 24, @@ -34,4 +35,14 @@ bool __must_check xchacha20poly1305_decrypt( const size_t ad_len, const u8 nonce[XCHACHA20POLY1305_NONCE_SIZE], const u8 key[CHACHA20POLY1305_KEY_SIZE]); +bool chacha20poly1305_encrypt_sg_inplace(struct scatterlist *src, size_t src_len, + const u8 *ad, const size_t ad_len, + const u64 nonce, + const u8 key[CHACHA20POLY1305_KEY_SIZE]); + +bool chacha20poly1305_decrypt_sg_inplace(struct scatterlist *src, size_t src_len, + const u8 *ad, const size_t ad_len, + const u64 nonce, + const u8 key[CHACHA20POLY1305_KEY_SIZE]); + #endif /* __CHACHA20POLY1305_H */ diff --git a/lib/crypto/chacha20poly1305-selftest.c b/lib/crypto/chacha20poly1305-selftest.c index d1ed0f27cfdb..465de46dbdef 100644 --- a/lib/crypto/chacha20poly1305-selftest.c +++ b/lib/crypto/chacha20poly1305-selftest.c @@ -7250,6 +7250,7 @@ bool __init chacha20poly1305_selftest(void) enum { MAXIMUM_TEST_BUFFER_LEN = 1UL << 12 }; size_t i; u8 *computed_output = NULL, *heap_src = NULL; + struct scatterlist sg_src; bool success = true, ret; heap_src = kmalloc(MAXIMUM_TEST_BUFFER_LEN, GFP_KERNEL); @@ -7280,6 +7281,29 @@ bool __init chacha20poly1305_selftest(void) } } + for (i = 0; i < ARRAY_SIZE(chacha20poly1305_enc_vectors); ++i) { + if (chacha20poly1305_enc_vectors[i].nlen != 8) + continue; + memcpy(heap_src, chacha20poly1305_enc_vectors[i].input, + chacha20poly1305_enc_vectors[i].ilen); + sg_init_one(&sg_src, heap_src, + chacha20poly1305_enc_vectors[i].ilen + POLY1305_DIGEST_SIZE); + chacha20poly1305_encrypt_sg_inplace(&sg_src, + chacha20poly1305_enc_vectors[i].ilen, + chacha20poly1305_enc_vectors[i].assoc, + chacha20poly1305_enc_vectors[i].alen, + get_unaligned_le64(chacha20poly1305_enc_vectors[i].nonce), + chacha20poly1305_enc_vectors[i].key); + if (memcmp(heap_src, + chacha20poly1305_enc_vectors[i].output, + chacha20poly1305_enc_vectors[i].ilen + + POLY1305_DIGEST_SIZE)) { + pr_err("chacha20poly1305 sg encryption self-test %zu: FAIL\n", + i + 1); + success = false; + } + } + for (i = 0; i < ARRAY_SIZE(chacha20poly1305_dec_vectors); ++i) { memset(computed_output, 0, MAXIMUM_TEST_BUFFER_LEN); ret = chacha20poly1305_decrypt(computed_output, @@ -7301,6 +7325,27 @@ bool __init chacha20poly1305_selftest(void) } } + for (i = 0; i < ARRAY_SIZE(chacha20poly1305_dec_vectors); ++i) { + memcpy(heap_src, chacha20poly1305_dec_vectors[i].input, + chacha20poly1305_dec_vectors[i].ilen); + sg_init_one(&sg_src, heap_src, + chacha20poly1305_dec_vectors[i].ilen); + ret = chacha20poly1305_decrypt_sg_inplace(&sg_src, + chacha20poly1305_dec_vectors[i].ilen, + chacha20poly1305_dec_vectors[i].assoc, + chacha20poly1305_dec_vectors[i].alen, + get_unaligned_le64(chacha20poly1305_dec_vectors[i].nonce), + chacha20poly1305_dec_vectors[i].key); + if (!decryption_success(ret, + chacha20poly1305_dec_vectors[i].failure, + memcmp(heap_src, chacha20poly1305_dec_vectors[i].output, + chacha20poly1305_dec_vectors[i].ilen - + POLY1305_DIGEST_SIZE))) { + pr_err("chacha20poly1305 sg decryption self-test %zu: FAIL\n", + i + 1); + success = false; + } + } for (i = 0; i < ARRAY_SIZE(xchacha20poly1305_enc_vectors); ++i) { memset(computed_output, 0, MAXIMUM_TEST_BUFFER_LEN); diff --git a/lib/crypto/chacha20poly1305.c b/lib/crypto/chacha20poly1305.c index c12ddbe9eb92..821e5cc9b14e 100644 --- a/lib/crypto/chacha20poly1305.c +++ b/lib/crypto/chacha20poly1305.c @@ -11,6 +11,7 @@ #include #include #include +#include #include #include @@ -205,6 +206,155 @@ bool xchacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len, } EXPORT_SYMBOL(xchacha20poly1305_decrypt); +static +bool chacha20poly1305_crypt_sg_inplace(struct scatterlist *src, + const size_t src_len, + const u8 *ad, const size_t ad_len, + const u64 nonce, + const u8 key[CHACHA20POLY1305_KEY_SIZE], + int encrypt) +{ + const u8 *pad0 = page_address(ZERO_PAGE(0)); + struct poly1305_desc_ctx poly1305_state; + u32 chacha_state[CHACHA_STATE_WORDS]; + struct sg_mapping_iter miter; + size_t partial = 0; + unsigned int flags; + bool ret = true; + int sl; + union { + struct { + u32 k[CHACHA_KEY_WORDS]; + __le64 iv[2]; + }; + u8 block0[POLY1305_KEY_SIZE]; + u8 chacha_stream[CHACHA_BLOCK_SIZE]; + struct { + u8 mac[2][POLY1305_DIGEST_SIZE]; + }; + __le64 lens[2]; + } b __aligned(16); + + chacha_load_key(b.k, key); + + b.iv[0] = 0; + b.iv[1] = cpu_to_le64(nonce); + + chacha_init(chacha_state, b.k, (u8 *)b.iv); + chacha_crypt(chacha_state, b.block0, pad0, sizeof(b.block0), 20); + poly1305_init(&poly1305_state, b.block0); + + if (unlikely(ad_len)) { + poly1305_update(&poly1305_state, ad, ad_len); + if (ad_len & 0xf) + poly1305_update(&poly1305_state, pad0, 0x10 - (ad_len & 0xf)); + } + + flags = SG_MITER_TO_SG; + if (!preemptible()) + flags |= SG_MITER_ATOMIC; + + sg_miter_start(&miter, src, sg_nents(src), flags); + + for (sl = src_len; sl > 0 && sg_miter_next(&miter); sl -= miter.length) { + u8 *addr = miter.addr; + size_t length = min_t(size_t, sl, miter.length); + + if (!encrypt) + poly1305_update(&poly1305_state, addr, length); + + if (unlikely(partial)) { + size_t l = min(length, CHACHA_BLOCK_SIZE - partial); + + crypto_xor(addr, b.chacha_stream + partial, l); + partial = (partial + l) & (CHACHA_BLOCK_SIZE - 1); + + addr += l; + length -= l; + } + + if (likely(length >= CHACHA_BLOCK_SIZE || length == sl)) { + size_t l = length; + + if (unlikely(length < sl)) + l &= ~(CHACHA_BLOCK_SIZE - 1); + chacha_crypt(chacha_state, addr, addr, l, 20); + addr += l; + length -= l; + } + + if (unlikely(length > 0)) { + chacha_crypt(chacha_state, b.chacha_stream, pad0, + CHACHA_BLOCK_SIZE, 20); + crypto_xor(addr, b.chacha_stream, length); + partial = length; + } + + if (encrypt) + poly1305_update(&poly1305_state, miter.addr, + min_t(size_t, sl, miter.length)); + } + + if (src_len & 0xf) + poly1305_update(&poly1305_state, pad0, 0x10 - (src_len & 0xf)); + + b.lens[0] = cpu_to_le64(ad_len); + b.lens[1] = cpu_to_le64(src_len); + poly1305_update(&poly1305_state, (u8 *)b.lens, sizeof(b.lens)); + + if (likely(sl <= -POLY1305_DIGEST_SIZE)) { + if (encrypt) { + poly1305_final(&poly1305_state, + miter.addr + miter.length + sl); + ret = true; + } else { + poly1305_final(&poly1305_state, b.mac[0]); + ret = !crypto_memneq(b.mac[0], + miter.addr + miter.length + sl, + POLY1305_DIGEST_SIZE); + } + } + + sg_miter_stop(&miter); + + if (unlikely(sl > -POLY1305_DIGEST_SIZE)) { + poly1305_final(&poly1305_state, b.mac[1]); + scatterwalk_map_and_copy(b.mac[encrypt], src, src_len, + sizeof(b.mac[1]), encrypt); + ret = encrypt || + !crypto_memneq(b.mac[0], b.mac[1], POLY1305_DIGEST_SIZE); + } + + memzero_explicit(chacha_state, sizeof(chacha_state)); + memzero_explicit(&b, sizeof(b)); + + return ret; +} + +bool chacha20poly1305_encrypt_sg_inplace(struct scatterlist *src, size_t src_len, + const u8 *ad, const size_t ad_len, + const u64 nonce, + const u8 key[CHACHA20POLY1305_KEY_SIZE]) +{ + return chacha20poly1305_crypt_sg_inplace(src, src_len, ad, ad_len, + nonce, key, 1); +} +EXPORT_SYMBOL(chacha20poly1305_encrypt_sg_inplace); + +bool chacha20poly1305_decrypt_sg_inplace(struct scatterlist *src, size_t src_len, + const u8 *ad, const size_t ad_len, + const u64 nonce, + const u8 key[CHACHA20POLY1305_KEY_SIZE]) +{ + if (unlikely(src_len < POLY1305_DIGEST_SIZE)) + return false; + + return chacha20poly1305_crypt_sg_inplace(src, + src_len - POLY1305_DIGEST_SIZE, + ad, ad_len, nonce, key, 0); +} +EXPORT_SYMBOL(chacha20poly1305_decrypt_sg_inplace); + static int __init mod_init(void) { if (!IS_ENABLED(CONFIG_CRYPTO_MANAGER_DISABLE_TESTS) && -- 2.20.1