From patchwork Fri Mar 1 17:59:11 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vitaly Chikunov X-Patchwork-Id: 10835839 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E79CD1515 for ; Fri, 1 Mar 2019 18:00:31 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DBA2B2FFA2 for ; Fri, 1 Mar 2019 18:00:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D02082FFDC; Fri, 1 Mar 2019 18:00:31 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EBE753002E for ; Fri, 1 Mar 2019 18:00:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389807AbfCAR7d (ORCPT ); Fri, 1 Mar 2019 12:59:33 -0500 Received: from vmicros1.altlinux.org ([194.107.17.57]:40220 "EHLO vmicros1.altlinux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389759AbfCAR7a (ORCPT ); Fri, 1 Mar 2019 12:59:30 -0500 Received: from imap.altlinux.org (imap.altlinux.org [194.107.17.38]) by vmicros1.altlinux.org (Postfix) with ESMTP id 0E0F972CCBC; Fri, 1 Mar 2019 20:59:28 +0300 (MSK) Received: from beacon.altlinux.org (unknown [185.6.174.98]) by imap.altlinux.org (Postfix) with ESMTPSA id C99394A4AE7; Fri, 1 Mar 2019 20:59:27 +0300 (MSK) From: Vitaly Chikunov To: Herbert Xu , David Howells , Mimi Zohar , Dmitry Kasatkin , linux-integrity@vger.kernel.org, keyrings@vger.kernel.org, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v7 04/11] crypto: akcipher - new verify API for public key algorithms Date: Fri, 1 Mar 2019 20:59:11 +0300 Message-Id: <20190301175918.29694-5-vt@altlinux.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20190301175918.29694-1-vt@altlinux.org> References: <20190301175918.29694-1-vt@altlinux.org> MIME-Version: 1.0 Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Previous akcipher .verify() just `decrypts' (using RSA encrypt which is using public key) signature to uncover message hash, which was then compared in upper level public_key_verify_signature() with the expected hash value, which itself was never passed into verify(). This approach was incompatible with EC-DSA family of algorithms, because, to verify a signature EC-DSA algorithm also needs a hash value as input; then it's used (together with a signature divided into halves `r||s') to produce a witness value, which is then compared with `r' to determine if the signature is correct. Thus, for EC-DSA, nor requirements of .verify() itself, nor its output expectations in public_key_verify_signature() wasn't sufficient. Make improved .verify() call which gets hash value as input and produce complete signature check without any output besides status. Now for the top level verification only crypto_akcipher_verify() needs to be called. Make sure that `digest' is in kmalloc'd memory (in place of `output`) in {public,tpm}_key_verify_signature() as insisted by Herbert Xu, and will be changed in the following commit. Cc: David Howells Cc: keyrings@vger.kernel.org Signed-off-by: Vitaly Chikunov --- crypto/asymmetric_keys/asym_tpm.c | 34 ++++++++----------------- crypto/asymmetric_keys/public_key.c | 34 ++++++++----------------- crypto/rsa-pkcs1pad.c | 29 +++++++++++++-------- crypto/testmgr.c | 50 ++++++++++++++++++++++--------------- include/crypto/akcipher.h | 40 ++++++++++++++++++----------- 5 files changed, 95 insertions(+), 92 deletions(-) diff --git a/crypto/asymmetric_keys/asym_tpm.c b/crypto/asymmetric_keys/asym_tpm.c index 5d4c270463f6..4e5b6fb57a94 100644 --- a/crypto/asymmetric_keys/asym_tpm.c +++ b/crypto/asymmetric_keys/asym_tpm.c @@ -744,12 +744,11 @@ static int tpm_key_verify_signature(const struct key *key, struct crypto_wait cwait; struct crypto_akcipher *tfm; struct akcipher_request *req; - struct scatterlist sig_sg, digest_sg; + struct scatterlist src_sg[2]; char alg_name[CRYPTO_MAX_ALG_NAME]; uint8_t der_pub_key[PUB_KEY_BUF_SIZE]; uint32_t der_pub_key_len; - void *output; - unsigned int outlen; + void *digest; int ret; pr_devel("==>%s()\n", __func__); @@ -782,35 +781,22 @@ static int tpm_key_verify_signature(const struct key *key, goto error_free_tfm; ret = -ENOMEM; - outlen = crypto_akcipher_maxsize(tfm); - output = kmalloc(outlen, GFP_KERNEL); - if (!output) + digest = kmemdup(sig->digest, sig->digest_size, GFP_KERNEL); + if (!digest) goto error_free_req; - sg_init_one(&sig_sg, sig->s, sig->s_size); - sg_init_one(&digest_sg, output, outlen); - akcipher_request_set_crypt(req, &sig_sg, &digest_sg, sig->s_size, - outlen); + sg_init_table(src_sg, 2); + sg_set_buf(&src_sg[0], sig->s, sig->s_size); + sg_set_buf(&src_sg[1], digest, sig->digest_size); + akcipher_request_set_crypt(req, src_sg, NULL, sig->s_size, + sig->digest_size); crypto_init_wait(&cwait); akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP, crypto_req_done, &cwait); - - /* Perform the verification calculation. This doesn't actually do the - * verification, but rather calculates the hash expected by the - * signature and returns that to us. - */ ret = crypto_wait_req(crypto_akcipher_verify(req), &cwait); - if (ret) - goto out_free_output; - - /* Do the actual verification step. */ - if (req->dst_len != sig->digest_size || - memcmp(sig->digest, output, sig->digest_size) != 0) - ret = -EKEYREJECTED; -out_free_output: - kfree(output); + kfree(digest); error_free_req: akcipher_request_free(req); error_free_tfm: diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c index c2e4e73fcf06..338f2b5352b1 100644 --- a/crypto/asymmetric_keys/public_key.c +++ b/crypto/asymmetric_keys/public_key.c @@ -233,10 +233,9 @@ int public_key_verify_signature(const struct public_key *pkey, struct crypto_wait cwait; struct crypto_akcipher *tfm; struct akcipher_request *req; - struct scatterlist sig_sg, digest_sg; + struct scatterlist src_sg[2]; char alg_name[CRYPTO_MAX_ALG_NAME]; - void *output; - unsigned int outlen; + void *digest; int ret; pr_devel("==>%s()\n", __func__); @@ -270,35 +269,22 @@ int public_key_verify_signature(const struct public_key *pkey, goto error_free_req; ret = -ENOMEM; - outlen = crypto_akcipher_maxsize(tfm); - output = kmalloc(outlen, GFP_KERNEL); - if (!output) + digest = kmemdup(sig->digest, sig->digest_size, GFP_KERNEL); + if (!digest) goto error_free_req; - sg_init_one(&sig_sg, sig->s, sig->s_size); - sg_init_one(&digest_sg, output, outlen); - akcipher_request_set_crypt(req, &sig_sg, &digest_sg, sig->s_size, - outlen); + sg_init_table(src_sg, 2); + sg_set_buf(&src_sg[0], sig->s, sig->s_size); + sg_set_buf(&src_sg[1], digest, sig->digest_size); + akcipher_request_set_crypt(req, src_sg, NULL, sig->s_size, + sig->digest_size); crypto_init_wait(&cwait); akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP, crypto_req_done, &cwait); - - /* Perform the verification calculation. This doesn't actually do the - * verification, but rather calculates the hash expected by the - * signature and returns that to us. - */ ret = crypto_wait_req(crypto_akcipher_verify(req), &cwait); - if (ret) - goto out_free_output; - - /* Do the actual verification step. */ - if (req->dst_len != sig->digest_size || - memcmp(sig->digest, output, sig->digest_size) != 0) - ret = -EKEYREJECTED; -out_free_output: - kfree(output); + kfree(digest); error_free_req: akcipher_request_free(req); error_free_tfm: diff --git a/crypto/rsa-pkcs1pad.c b/crypto/rsa-pkcs1pad.c index 94382fa2c6ac..29c336068dc0 100644 --- a/crypto/rsa-pkcs1pad.c +++ b/crypto/rsa-pkcs1pad.c @@ -488,14 +488,21 @@ static int pkcs1pad_verify_complete(struct akcipher_request *req, int err) err = 0; - if (req->dst_len < dst_len - pos) - err = -EOVERFLOW; - req->dst_len = dst_len - pos; - - if (!err) - sg_copy_from_buffer(req->dst, - sg_nents_for_len(req->dst, req->dst_len), - out_buf + pos, req->dst_len); + if (req->dst_len != dst_len - pos) { + err = -EKEYREJECTED; + req->dst_len = dst_len - pos; + goto done; + } + /* Extract appended digest. */ + sg_pcopy_to_buffer(req->src, + sg_nents_for_len(req->src, + req->src_len + req->dst_len), + req_ctx->out_buf + ctx->key_size, + req->dst_len, ctx->key_size); + /* Do the actual verification step. */ + if (memcmp(req_ctx->out_buf + ctx->key_size, out_buf + pos, + req->dst_len) != 0) + err = -EKEYREJECTED; done: kzfree(req_ctx->out_buf); @@ -532,10 +539,12 @@ static int pkcs1pad_verify(struct akcipher_request *req) struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); int err; - if (!ctx->key_size || req->src_len < ctx->key_size) + if (WARN_ON(req->dst) || + WARN_ON(!req->dst_len) || + !ctx->key_size || req->src_len < ctx->key_size) return -EINVAL; - req_ctx->out_buf = kmalloc(ctx->key_size, GFP_KERNEL); + req_ctx->out_buf = kmalloc(ctx->key_size + req->dst_len, GFP_KERNEL); if (!req_ctx->out_buf) return -ENOMEM; diff --git a/crypto/testmgr.c b/crypto/testmgr.c index 8386038d67c7..443d5b6f1045 100644 --- a/crypto/testmgr.c +++ b/crypto/testmgr.c @@ -2503,7 +2503,7 @@ static int test_akcipher_one(struct crypto_akcipher *tfm, struct crypto_wait wait; unsigned int out_len_max, out_len = 0; int err = -ENOMEM; - struct scatterlist src, dst, src_tab[2]; + struct scatterlist src, dst, src_tab[3]; const char *m, *c; unsigned int m_size, c_size; const char *op; @@ -2526,13 +2526,12 @@ static int test_akcipher_one(struct crypto_akcipher *tfm, if (err) goto free_req; - err = -ENOMEM; - out_len_max = crypto_akcipher_maxsize(tfm); - /* * First run test which do not require a private key, such as * encrypt or verify. */ + err = -ENOMEM; + out_len_max = crypto_akcipher_maxsize(tfm); outbuf_enc = kzalloc(out_len_max, GFP_KERNEL); if (!outbuf_enc) goto free_req; @@ -2558,12 +2557,20 @@ static int test_akcipher_one(struct crypto_akcipher *tfm, goto free_all; memcpy(xbuf[0], m, m_size); - sg_init_table(src_tab, 2); + sg_init_table(src_tab, 3); sg_set_buf(&src_tab[0], xbuf[0], 8); sg_set_buf(&src_tab[1], xbuf[0] + 8, m_size - 8); - sg_init_one(&dst, outbuf_enc, out_len_max); - akcipher_request_set_crypt(req, src_tab, &dst, m_size, - out_len_max); + if (vecs->siggen_sigver_test) { + if (WARN_ON(c_size > PAGE_SIZE)) + goto free_all; + memcpy(xbuf[1], c, c_size); + sg_set_buf(&src_tab[2], xbuf[1], c_size); + akcipher_request_set_crypt(req, src_tab, NULL, m_size, c_size); + } else { + sg_init_one(&dst, outbuf_enc, out_len_max); + akcipher_request_set_crypt(req, src_tab, &dst, m_size, + out_len_max); + } akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG, crypto_req_done, &wait); @@ -2576,18 +2583,21 @@ static int test_akcipher_one(struct crypto_akcipher *tfm, pr_err("alg: akcipher: %s test failed. err %d\n", op, err); goto free_all; } - if (req->dst_len != c_size) { - pr_err("alg: akcipher: %s test failed. Invalid output len\n", - op); - err = -EINVAL; - goto free_all; - } - /* verify that encrypted message is equal to expected */ - if (memcmp(c, outbuf_enc, c_size)) { - pr_err("alg: akcipher: %s test failed. Invalid output\n", op); - hexdump(outbuf_enc, c_size); - err = -EINVAL; - goto free_all; + if (!vecs->siggen_sigver_test) { + if (req->dst_len != c_size) { + pr_err("alg: akcipher: %s test failed. Invalid output len\n", + op); + err = -EINVAL; + goto free_all; + } + /* verify that encrypted message is equal to expected */ + if (memcmp(c, outbuf_enc, c_size) != 0) { + pr_err("alg: akcipher: %s test failed. Invalid output\n", + op); + hexdump(outbuf_enc, c_size); + err = -EINVAL; + goto free_all; + } } /* diff --git a/include/crypto/akcipher.h b/include/crypto/akcipher.h index f537fad1989f..28ffa9ef03a9 100644 --- a/include/crypto/akcipher.h +++ b/include/crypto/akcipher.h @@ -19,14 +19,20 @@ * * @base: Common attributes for async crypto requests * @src: Source data - * @dst: Destination data + * For verify op this is signature + digest, in that case + * total size of @src is @src_len + @dst_len. + * @dst: Destination data (Should be NULL for verify op) * @src_len: Size of the input buffer - * @dst_len: Size of the output buffer. It needs to be at least - * as big as the expected result depending on the operation + * For verify op it's size of signature part of @src, this part + * is supposed to be operated by cipher. + * @dst_len: Size of @dst buffer (for all ops except verify). + * It needs to be at least as big as the expected result + * depending on the operation. * After operation it will be updated with the actual size of the * result. * In case of error where the dst sgl size was insufficient, * it will be updated to the size required for the operation. + * For verify op this is size of digest part in @src. * @__ctx: Start of private context data */ struct akcipher_request { @@ -55,10 +61,9 @@ struct crypto_akcipher { * algorithm. In case of error, where the dst_len was insufficient, * the req->dst_len will be updated to the size required for the * operation - * @verify: Function performs a sign operation as defined by public key - * algorithm. In case of error, where the dst_len was insufficient, - * the req->dst_len will be updated to the size required for the - * operation + * @verify: Function performs a complete verify operation as defined by + * public key algorithm, returning verification status. Requires + * digest value as input parameter. * @encrypt: Function performs an encrypt operation as defined by public key * algorithm. In case of error, where the dst_len was insufficient, * the req->dst_len will be updated to the size required for the @@ -238,9 +243,10 @@ static inline void akcipher_request_set_callback(struct akcipher_request *req, * * @req: public key request * @src: ptr to input scatter list - * @dst: ptr to output scatter list + * @dst: ptr to output scatter list or NULL for verify op * @src_len: size of the src input scatter list to be processed - * @dst_len: size of the dst output scatter list + * @dst_len: size of the dst output scatter list or size of signature + * portion in @src for verify op */ static inline void akcipher_request_set_crypt(struct akcipher_request *req, struct scatterlist *src, @@ -349,14 +355,18 @@ static inline int crypto_akcipher_sign(struct akcipher_request *req) } /** - * crypto_akcipher_verify() - Invoke public key verify operation + * crypto_akcipher_verify() - Invoke public key signature verification * - * Function invokes the specific public key verify operation for a given - * public key algorithm + * Function invokes the specific public key signature verification operation + * for a given public key algorithm. * * @req: asymmetric key request * - * Return: zero on success; error code in case of error + * Note: req->dst should be NULL, req->src should point to SG of size + * (req->src_size + req->dst_size), containing signature (of req->src_size + * length) with appended digest (of req->dst_size length). + * + * Return: zero on verification success; error code in case of error. */ static inline int crypto_akcipher_verify(struct akcipher_request *req) { @@ -366,7 +376,9 @@ static inline int crypto_akcipher_verify(struct akcipher_request *req) int ret = -ENOSYS; crypto_stats_get(calg); - if (alg->verify) + if (req->dst || !req->dst_len) + ret = -EINVAL; + else if (alg->verify) ret = alg->verify(req); crypto_stats_akcipher_verify(ret, calg); return ret;