From patchwork Mon May 3 23:34:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vitaly Chikunov X-Patchwork-Id: 12237231 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 C007AC43460 for ; Mon, 3 May 2021 23:35:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9B82661208 for ; Mon, 3 May 2021 23:35:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229948AbhECXgA (ORCPT ); Mon, 3 May 2021 19:36:00 -0400 Received: from vmicros1.altlinux.org ([194.107.17.57]:57742 "EHLO vmicros1.altlinux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229926AbhECXgA (ORCPT ); Mon, 3 May 2021 19:36:00 -0400 Received: from imap.altlinux.org (imap.altlinux.org [194.107.17.38]) by vmicros1.altlinux.org (Postfix) with ESMTP id A973472C8BA; Tue, 4 May 2021 02:35:05 +0300 (MSK) Received: from beacon.altlinux.org (unknown [193.43.10.250]) by imap.altlinux.org (Postfix) with ESMTPSA id 83A884A46E8; Tue, 4 May 2021 02:35:05 +0300 (MSK) From: Vitaly Chikunov To: Mimi Zohar , Dmitry Kasatkin , linux-integrity@vger.kernel.org Subject: [PATCH 1/2] ima-evm-utils: Allow manual setting keyid for signing Date: Tue, 4 May 2021 02:34:51 +0300 Message-Id: <20210503233452.4048462-2-vt@altlinux.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20210503233452.4048462-1-vt@altlinux.org> References: <20210503233452.4048462-1-vt@altlinux.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org Allow user to set signature's keyid using `--keyid' option. Keyid should correspond to SKID in certificate, when keyid is calculated using SHA-1 in libimaevm it may mismatch keyid extracted by the kernel from SKID of certificate (the way public key is presented to the kernel), thus making signatures not verifiable. This may happen when certificate is using non SHA-1 SKID (see rfc7093) or just 'unique number' (see rfc5280 4.2.1.2). As a last resort user may specify arbitrary keyid using the new option. This commit creates backward compatible ABI change for libimaevm, because of adding additional parameter to imaevm_params - older libimaevm can work with newer client. Signed-off-by: Vitaly Chikunov --- README | 1 + src/evmctl.c | 14 ++++++++++++++ src/imaevm.h | 1 + src/libimaevm.c | 8 +++++--- tests/sign_verify.test | 1 + 5 files changed, 22 insertions(+), 3 deletions(-) diff --git a/README b/README index 321045d..8cd66e0 100644 --- a/README +++ b/README @@ -48,6 +48,7 @@ OPTIONS --xattr-user store xattrs in user namespace (for testing purposes) --rsa use RSA key type and signing scheme v1 -k, --key path to signing key (default: /etc/keys/{privkey,pubkey}_evm.pem) + --keyid val overwrite signature keyid with a value (for signing) -o, --portable generate portable EVM signatures -p, --pass password for encrypted signing key -r, --recursive recurse into directories (sign) diff --git a/src/evmctl.c b/src/evmctl.c index 1815f55..7983299 100644 --- a/src/evmctl.c +++ b/src/evmctl.c @@ -2446,6 +2446,7 @@ static void usage(void) " --xattr-user store xattrs in user namespace (for testing purposes)\n" " --rsa use RSA key type and signing scheme v1\n" " -k, --key path to signing key (default: /etc/keys/{privkey,pubkey}_evm.pem)\n" + " --keyid val overwrite signature keyid with a value (for signing)\n" " -o, --portable generate portable EVM signatures\n" " -p, --pass password for encrypted signing key\n" " -r, --recursive recurse into directories (sign)\n" @@ -2525,6 +2526,7 @@ static struct option opts[] = { {"xattr-user", 0, 0, 140}, {"ignore-violations", 0, 0, 141}, {"pcrs", 1, 0, 142}, + {"keyid", 1, 0, 143}, {} }; @@ -2569,6 +2571,8 @@ int main(int argc, char *argv[]) { int err = 0, c, lind; ENGINE *eng = NULL; + unsigned long int keyid; + char *eptr; #if !(OPENSSL_VERSION_NUMBER < 0x10100000) OPENSSL_init_crypto( @@ -2713,6 +2717,16 @@ int main(int argc, char *argv[]) } pcrfile[npcrfile++] = optarg; break; + case 143: + errno = 0; + keyid = strtoul(optarg, &eptr, 16); + if (errno || eptr - optarg != strlen(optarg) || + keyid > UINT_MAX || keyid == 0) { + log_err("Invalid keyid value.\n"); + exit(1); + } + imaevm_params.keyid = keyid; + break; case '?': exit(1); break; diff --git a/src/imaevm.h b/src/imaevm.h index 4503919..9f38059 100644 --- a/src/imaevm.h +++ b/src/imaevm.h @@ -196,6 +196,7 @@ struct libimaevm_params { const char *hash_algo; const char *keyfile; const char *keypass; + uint32_t keyid; /* keyid overriding value, unless 0. */ }; struct RSA_ASN1_template { diff --git a/src/libimaevm.c b/src/libimaevm.c index fa6c278..481d29d 100644 --- a/src/libimaevm.c +++ b/src/libimaevm.c @@ -45,6 +45,7 @@ #include #include #include +#include #include #include #include @@ -894,7 +895,6 @@ static int sign_hash_v2(const char *algo, const unsigned char *hash, const EVP_MD *md; size_t sigsize; const char *st; - uint32_t keyid; if (!hash) { log_err("sign_hash_v2: hash is null\n"); @@ -932,8 +932,10 @@ static int sign_hash_v2(const char *algo, const unsigned char *hash, return -1; } - calc_keyid_v2(&keyid, name, pkey); - hdr->keyid = keyid; + if (imaevm_params.keyid) + hdr->keyid = htonl(imaevm_params.keyid); + else + calc_keyid_v2(&hdr->keyid, name, pkey); st = "EVP_PKEY_CTX_new"; if (!(ctx = EVP_PKEY_CTX_new(pkey, NULL))) diff --git a/tests/sign_verify.test b/tests/sign_verify.test index 288e133..2c21812 100755 --- a/tests/sign_verify.test +++ b/tests/sign_verify.test @@ -359,6 +359,7 @@ sign_verify rsa1024 sha256 0x0301 --rsa sign_verify rsa1024 md5 0x030201:K:0080 sign_verify rsa1024 sha1 0x030202:K:0080 sign_verify rsa1024 sha224 0x030207:K:0080 +expect_pass check_sign TYPE=ima KEY=rsa1024 ALG=sha256 PREFIX=0x030204aabbccdd0080 OPTS=--keyid=aabbccdd sign_verify rsa1024 sha256 0x030204:K:0080 try_different_keys try_different_sigs