From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AAD33BA32 for ; Tue, 7 Mar 2023 17:13:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0EB79C433EF; Tue, 7 Mar 2023 17:13:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678209238; bh=/CiLiZ4ZhIUoIABFC7/F5Aq1DKQhCCrH8EVglSmFoNY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mKLOVVXkG97GgwHlQmIDVrokXp2HOCcAHx1CWtCLvxBnAItzsaz3RL6xEZev/mdxS Voc1Tt2kaneod0jhnVmEqeQshrUfyQVy5gNdcq3VpeAw1s1+e14A/ttaRYXy7hglQV SlXn8V+5gouIjhGCHPJ9cNV594saMpO6Opmw8dp0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Denis Kenzior , Stefan Berger , Jarkko Sakkinen , Sasha Levin Subject: [PATCH 6.2 0124/1001] KEYS: asymmetric: Fix ECDSA use via keyctl uapi Date: Tue, 7 Mar 2023 17:48:16 +0100 Message-Id: <20230307170027.459853336@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230307170022.094103862@linuxfoundation.org> References: <20230307170022.094103862@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Denis Kenzior [ Upstream commit 10de7b54293995368c52d9aa153f3e7a359f04a1 ] When support for ECDSA keys was added, constraints for data & signature sizes were never updated. This makes it impossible to use such keys via keyctl API from userspace. Update constraint on max_data_size to 64 bytes in order to support SHA512-based signatures. Also update the signature length constraints per ECDSA signature encoding described in RFC 5480. Fixes: 299f561a6693 ("x509: Add support for parsing x509 certs with ECDSA keys") Signed-off-by: Denis Kenzior Reviewed-by: Stefan Berger Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen Signed-off-by: Sasha Levin --- crypto/asymmetric_keys/public_key.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c index 2f8352e888602..eca5671ad3f22 100644 --- a/crypto/asymmetric_keys/public_key.c +++ b/crypto/asymmetric_keys/public_key.c @@ -186,8 +186,28 @@ static int software_key_query(const struct kernel_pkey_params *params, len = crypto_akcipher_maxsize(tfm); info->key_size = len * 8; - info->max_data_size = len; - info->max_sig_size = len; + + if (strncmp(pkey->pkey_algo, "ecdsa", 5) == 0) { + /* + * ECDSA key sizes are much smaller than RSA, and thus could + * operate on (hashed) inputs that are larger than key size. + * For example SHA384-hashed input used with secp256r1 + * based keys. Set max_data_size to be at least as large as + * the largest supported hash size (SHA512) + */ + info->max_data_size = 64; + + /* + * Verify takes ECDSA-Sig (described in RFC 5480) as input, + * which is actually 2 'key_size'-bit integers encoded in + * ASN.1. Account for the ASN.1 encoding overhead here. + */ + info->max_sig_size = 2 * (len + 3) + 2; + } else { + info->max_data_size = len; + info->max_sig_size = len; + } + info->max_enc_size = len; info->max_dec_size = len; info->supported_ops = (KEYCTL_SUPPORTS_ENCRYPT | -- 2.39.2