[v2] crypto: aesni - add ccm(aes) algorithm implementation

Message ID	20201201194556.5220-1-ardb@kernel.org
State	New
Headers	show Return-Path: <linux-crypto-owner@kernel.org> From: Ard Biesheuvel <ardb@kernel.org> To: linux-crypto@vger.kernel.org Cc: herbert@gondor.apana.org.au, greearb@candelatech.com, Ard Biesheuvel <ardb@kernel.org>, Steve deRosier <derosier@cal-sierra.com> Subject: [PATCH v2] crypto: aesni - add ccm(aes) algorithm implementation Date: Tue, 1 Dec 2020 20:45:56 +0100 Message-Id: <20201201194556.5220-1-ardb@kernel.org> Precedence: bulk
Series	[v2] crypto: aesni - add ccm(aes) algorithm implementation \| expand [v2] crypto: aesni - add ccm(aes) algorithm implementation

diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c index ad8a7188a2bf..d90b03d9b420 100644 --- a/arch/x86/crypto/aesni-intel_glue.c +++ b/arch/x86/crypto/aesni-intel_glue.c @@ -97,12 +97,13 @@ asmlinkage void aesni_cbc_dec(struct crypto_aes_ctx *ctx, u8 *out, #define AVX_GEN2_OPTSIZE 640 #define AVX_GEN4_OPTSIZE 4096 +asmlinkage void aesni_ctr_enc(struct crypto_aes_ctx *ctx, u8 *out, + const u8 *in, unsigned int len, u8 *iv); + #ifdef CONFIG_X86_64 static void (*aesni_ctr_enc_tfm)(struct crypto_aes_ctx *ctx, u8 *out, const u8 *in, unsigned int len, u8 *iv); -asmlinkage void aesni_ctr_enc(struct crypto_aes_ctx *ctx, u8 *out, - const u8 *in, unsigned int len, u8 *iv); asmlinkage void aesni_xts_crypt8(const struct crypto_aes_ctx *ctx, u8 *out, const u8 *in, bool enc, le128 *iv); @@ -454,6 +455,377 @@ static int cbc_decrypt(struct skcipher_request *req) return err; } +static int aesni_ccm_setkey(struct crypto_aead *tfm, const u8 *in_key, + unsigned int key_len) +{ + struct crypto_aes_ctx *ctx = crypto_aead_ctx(tfm); + + return aes_set_key_common(crypto_aead_tfm(tfm), ctx, in_key, key_len); +} + +static int aesni_ccm_setauthsize(struct crypto_aead *tfm, unsigned int authsize) +{ + if ((authsize & 1) || authsize < 4) + return -EINVAL; + return 0; +} + +static int ccm_set_msg_len(u8 *block, unsigned int msglen, int csize) +{ + __be32 data; + + memset(block, 0, csize); + block += csize; + + if (csize >= 4) + csize = 4; + else if (msglen > (1 << (8 * csize))) + return -EOVERFLOW; + + data = cpu_to_be32(msglen); + memcpy(block - csize, (u8 *)&data + 4 - csize, csize); + + return 0; +} + +static int ccm_init_mac(struct aead_request *req, u8 maciv[], u32 msglen) +{ + struct crypto_aead *aead = crypto_aead_reqtfm(req); + __be32 *n = (__be32 *)&maciv[AES_BLOCK_SIZE - 8]; + u32 l = req->iv[0] + 1; + + /* verify that CCM dimension 'L' is set correctly in the IV */ + if (l < 2 || l > 8) + return -EINVAL; + + /* verify that msglen can in fact be represented in L bytes */ + if (l < 4 && msglen >> (8 * l)) + return -EOVERFLOW; + + /* + * Even if the CCM spec allows L values of up to 8, the Linux cryptoapi + * uses a u32 type to represent msglen so the top 4 bytes are always 0. + */ + n[0] = 0; + n[1] = cpu_to_be32(msglen); + + memcpy(maciv, req->iv, AES_BLOCK_SIZE - l); + + /* + * Meaning of byte 0 according to CCM spec (RFC 3610/NIST 800-38C) + * - bits 0..2 : max # of bytes required to represent msglen, minus 1 + * (already set by caller) + * - bits 3..5 : size of auth tag (1 => 4 bytes, 2 => 6 bytes, etc) + * - bit 6 : indicates presence of authenticate-only data + */ + maciv[0] |= (crypto_aead_authsize(aead) - 2) << 2; + if (req->assoclen) + maciv[0] |= 0x40; + + memset(&req->iv[AES_BLOCK_SIZE - l], 0, l); + return ccm_set_msg_len(maciv + AES_BLOCK_SIZE - l, msglen, l); +} + +static int compute_mac(struct crypto_aes_ctx *ctx, u8 mac[], u8 *data, int n, + unsigned int ilen, u8 *idata, bool do_simd) +{ + unsigned int bs = AES_BLOCK_SIZE; + u8 *odata = mac; + int datalen, getlen; + + datalen = n; + + /* first time in here, block may be partially filled. */ + getlen = bs - ilen; + if (datalen >= getlen) { + memcpy(idata + ilen, data, getlen); + + if (likely(do_simd)) { + aesni_cbc_enc(ctx, odata, idata, AES_BLOCK_SIZE, odata); + } else { + crypto_xor(odata, idata, AES_BLOCK_SIZE); + aes_encrypt(ctx, odata, odata); + } + + datalen -= getlen; + data += getlen; + ilen = 0; + } + + /* now encrypt rest of data */ + while (datalen >= bs) { + if (likely(do_simd)) { + aesni_cbc_enc(ctx, odata, data, AES_BLOCK_SIZE, odata); + } else { + crypto_xor(odata, data, AES_BLOCK_SIZE); + aes_encrypt(ctx, odata, odata); + } + + datalen -= bs; + data += bs; + } + + /* check and see if there's leftover data that wasn't + * enough to fill a block. + */ + if (datalen) { + memcpy(idata + ilen, data, datalen); + ilen += datalen; + } + return ilen; +} + +static void ccm_calculate_auth_mac(struct aead_request *req, + struct crypto_aes_ctx *ctx, u8 mac[], + struct scatterlist *src, + bool do_simd) +{ + unsigned int len = req->assoclen; + struct scatter_walk walk; + u8 idata[AES_BLOCK_SIZE]; + unsigned int ilen; + struct { + __be16 l; + __be32 h; + } __packed *ltag = (void *)idata; + + /* prepend the AAD with a length tag */ + if (len < 0xff00) { + ltag->l = cpu_to_be16(len); + ilen = 2; + } else { + ltag->l = cpu_to_be16(0xfffe); + ltag->h = cpu_to_be32(len); + ilen = 6; + } + + scatterwalk_start(&walk, src); + + while (len) { + u8 *src; + int n; + + n = scatterwalk_clamp(&walk, len); + if (!n) { + scatterwalk_start(&walk, sg_next(walk.sg)); + n = scatterwalk_clamp(&walk, len); + } + src = scatterwalk_map(&walk); + + ilen = compute_mac(ctx, mac, src, n, ilen, idata, do_simd); + len -= n; + + scatterwalk_unmap(src); + scatterwalk_advance(&walk, n); + scatterwalk_done(&walk, 0, len); + } + + /* any leftover needs padding and then encrypted */ + if (ilen) { + crypto_xor(mac, idata, ilen); + if (likely(do_simd)) + aesni_enc(ctx, mac, mac); + else + aes_encrypt(ctx, mac, mac); + } +} + +static int aesni_ccm_encrypt(struct aead_request *req) +{ + struct crypto_aead *aead = crypto_aead_reqtfm(req); + struct crypto_aes_ctx *ctx = aes_ctx(crypto_aead_ctx(aead)); + bool const do_simd = crypto_simd_usable(); + u8 __aligned(8) mac[AES_BLOCK_SIZE]; + u8 __aligned(8) buf[AES_BLOCK_SIZE]; + struct skcipher_walk walk; + u32 l = req->iv[0] + 1; + int err; + + err = ccm_init_mac(req, mac, req->cryptlen); + if (err) + return err; + + if (likely(do_simd)) { + kernel_fpu_begin(); + aesni_enc(ctx, mac, mac); + } else { + aes_encrypt(ctx, mac, mac); + } + + if (req->assoclen) + ccm_calculate_auth_mac(req, ctx, mac, req->src, do_simd); + + req->iv[AES_BLOCK_SIZE - 1] = 0x1; + err = skcipher_walk_aead_encrypt(&walk, req, true); + + while (walk.nbytes >= AES_BLOCK_SIZE) { + int len = walk.nbytes & AES_BLOCK_MASK; + int n; + + for (n = 0; n < len; n += AES_BLOCK_SIZE) { + if (likely(do_simd)) { + aesni_cbc_enc(ctx, mac, walk.src.virt.addr + n, + AES_BLOCK_SIZE, mac); + } else { + crypto_xor(mac, walk.src.virt.addr + n, + AES_BLOCK_SIZE); + aes_encrypt(ctx, mac, mac); + + aes_encrypt(ctx, buf, walk.iv); + crypto_inc(walk.iv, AES_BLOCK_SIZE); + crypto_xor_cpy(walk.dst.virt.addr + n, + walk.src.virt.addr + n, + buf, AES_BLOCK_SIZE); + } + } + if (likely(do_simd)) + aesni_ctr_enc(ctx, walk.dst.virt.addr, + walk.src.virt.addr, len, walk.iv); + + err = skcipher_walk_done(&walk, walk.nbytes & ~AES_BLOCK_MASK); + } + if (walk.nbytes) { + if (likely(do_simd)) + aesni_enc(ctx, buf, walk.iv); + else + aes_encrypt(ctx, buf, walk.iv); + + crypto_xor(mac, walk.src.virt.addr, walk.nbytes); + crypto_xor_cpy(walk.dst.virt.addr, walk.src.virt.addr, + buf, walk.nbytes); + + if (likely(do_simd)) + aesni_enc(ctx, mac, mac); + else + aes_encrypt(ctx, mac, mac); + + err = skcipher_walk_done(&walk, 0); + } + + if (err) + goto fail; + + memset(walk.iv + AES_BLOCK_SIZE - l, 0, l); + + if (likely(do_simd)) { + aesni_ctr_enc(ctx, mac, mac, AES_BLOCK_SIZE, walk.iv); + } else { + aes_encrypt(ctx, buf, walk.iv); + crypto_xor(mac, buf, AES_BLOCK_SIZE); + } + + /* copy authtag to end of dst */ + scatterwalk_map_and_copy(mac, req->dst, req->assoclen + req->cryptlen, + crypto_aead_authsize(aead), 1); + +fail: + if (likely(do_simd)) + kernel_fpu_end(); + return err; +} + +static int aesni_ccm_decrypt(struct aead_request *req) +{ + struct crypto_aead *aead = crypto_aead_reqtfm(req); + struct crypto_aes_ctx *ctx = aes_ctx(crypto_aead_ctx(aead)); + unsigned int authsize = crypto_aead_authsize(aead); + bool const do_simd = crypto_simd_usable(); + u8 __aligned(8) mac[AES_BLOCK_SIZE]; + u8 __aligned(8) tag[AES_BLOCK_SIZE]; + u8 __aligned(8) buf[AES_BLOCK_SIZE]; + struct skcipher_walk walk; + u32 l = req->iv[0] + 1; + int err; + + err = ccm_init_mac(req, mac, req->cryptlen - authsize); + if (err) + return err; + + /* copy authtag from end of src */ + scatterwalk_map_and_copy(tag, req->src, + req->assoclen + req->cryptlen - authsize, + authsize, 0); + + if (likely(do_simd)) { + kernel_fpu_begin(); + aesni_enc(ctx, mac, mac); + } else { + aes_encrypt(ctx, mac, mac); + } + + if (req->assoclen) + ccm_calculate_auth_mac(req, ctx, mac, req->src, do_simd); + + req->iv[AES_BLOCK_SIZE - 1] = 0x1; + err = skcipher_walk_aead_decrypt(&walk, req, true); + + while (walk.nbytes >= AES_BLOCK_SIZE) { + int len = walk.nbytes & AES_BLOCK_MASK; + int n; + + if (likely(do_simd)) + aesni_ctr_enc(ctx, walk.dst.virt.addr, + walk.src.virt.addr, len, walk.iv); + + for (n = 0; n < len; n += AES_BLOCK_SIZE) { + if (likely(do_simd)) { + aesni_cbc_enc(ctx, mac, walk.dst.virt.addr + n, + AES_BLOCK_SIZE, mac); + } else { + aes_encrypt(ctx, buf, walk.iv); + crypto_inc(walk.iv, AES_BLOCK_SIZE); + crypto_xor_cpy(walk.dst.virt.addr + n, + walk.src.virt.addr + n, + buf, AES_BLOCK_SIZE); + + crypto_xor(mac, walk.dst.virt.addr + n, + AES_BLOCK_SIZE); + aes_encrypt(ctx, mac, mac); + } + } + + err = skcipher_walk_done(&walk, walk.nbytes & ~AES_BLOCK_MASK); + } + if (walk.nbytes) { + if (likely(do_simd)) + aesni_enc(ctx, buf, walk.iv); + else + aes_encrypt(ctx, buf, walk.iv); + + crypto_xor_cpy(walk.dst.virt.addr, walk.src.virt.addr, + buf, walk.nbytes); + crypto_xor(mac, walk.dst.virt.addr, walk.nbytes); + + if (likely(do_simd)) + aesni_enc(ctx, mac, mac); + else + aes_encrypt(ctx, mac, mac); + + err = skcipher_walk_done(&walk, 0); + } + + if (err) + goto fail; + + memset(walk.iv + AES_BLOCK_SIZE - l, 0, l); + + if (likely(do_simd)) { + aesni_ctr_enc(ctx, mac, mac, AES_BLOCK_SIZE, walk.iv); + } else { + aes_encrypt(ctx, buf, walk.iv); + crypto_xor(mac, buf, AES_BLOCK_SIZE); + } + + /* compare calculated auth tag with the stored one */ + if (crypto_memneq(mac, tag, authsize)) + err = -EBADMSG; + +fail: + if (likely(do_simd)) + kernel_fpu_end(); + return err; +} + #ifdef CONFIG_X86_64 static void ctr_crypt_final(struct crypto_aes_ctx *ctx, struct skcipher_walk *walk) @@ -1045,10 +1417,28 @@ static struct aead_alg aesni_aeads[] = { { .cra_module = THIS_MODULE, }, } }; + #else static struct aead_alg aesni_aeads[0]; #endif +static struct aead_alg aesni_ccm_aead = { + .base.cra_name = "ccm(aes)", + .base.cra_driver_name = "ccm-aesni", + .base.cra_priority = 400, + .base.cra_blocksize = 1, + .base.cra_ctxsize = sizeof(struct crypto_aes_ctx), + .base.cra_module = THIS_MODULE, + + .setkey = aesni_ccm_setkey, + .setauthsize = aesni_ccm_setauthsize, + .encrypt = aesni_ccm_encrypt, + .decrypt = aesni_ccm_decrypt, + .ivsize = AES_BLOCK_SIZE, + .chunksize = AES_BLOCK_SIZE, + .maxauthsize = AES_BLOCK_SIZE, +}; + static struct simd_aead_alg *aesni_simd_aeads[ARRAY_SIZE(aesni_aeads)]; static const struct x86_cpu_id aesni_cpu_id[] = { @@ -1098,8 +1488,17 @@ static int __init aesni_init(void) if (err) goto unregister_skciphers; + if (IS_ENABLED(CONFIG_X86_64)) { + err = crypto_register_aead(&aesni_ccm_aead); + if (err) + goto unregister_aeads; + } + return 0; +unregister_aeads: + simd_unregister_aeads(aesni_aeads, ARRAY_SIZE(aesni_aeads), + aesni_simd_aeads); unregister_skciphers: simd_unregister_skciphers(aesni_skciphers, ARRAY_SIZE(aesni_skciphers), aesni_simd_skciphers); @@ -1110,6 +1509,9 @@ static int __init aesni_init(void) static void __exit aesni_exit(void) { + if (IS_ENABLED(CONFIG_X86_64)) + crypto_unregister_aead(&aesni_ccm_aead); + simd_unregister_aeads(aesni_aeads, ARRAY_SIZE(aesni_aeads), aesni_simd_aeads); simd_unregister_skciphers(aesni_skciphers, ARRAY_SIZE(aesni_skciphers),

[v2] crypto: aesni - add ccm(aes) algorithm implementation

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