From patchwork Thu May 23 13:23:37 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 13671843 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 A88B014A60D; Thu, 23 May 2024 13:23:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716470629; cv=none; b=oBQcvq+gfK74HJEn0Q9i7fOnuqZ7A9ooBqCnOr60RQJGxRk/+TLDS8ztdV0ytkFd/4SciMF3/PR6J73rbPuluJu7hsIVblLu7ZamNIFNLCR5MT/U+BRl6vtRE2H3c/PT0KLnJbroa31AXeuNPP7G27P272LugowlPNyVwgdHXCA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716470629; c=relaxed/simple; bh=Eji3OK0kgA/1QMg7rgMlIDsUrIG2CMxWsZn7mehH8BI=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=Hj4iYykL9By/Ujq7avzM8gdDyQ+6XK9jOimm03c1ImIFVlQqGJDiviZ7Dimwjb6xciyNIfYuj3fQQAoYZgHv1Hz+i0/hHni2bn+06PILlQ4GAkMnwnldl7fNucZdFbJhleecoCuhP1KaZBl3cuD/XJ0SumVUMWdAFvgWOdsux3k= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=mU0CSDIR; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="mU0CSDIR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2DBAEC2BD10; Thu, 23 May 2024 13:23:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1716470629; bh=Eji3OK0kgA/1QMg7rgMlIDsUrIG2CMxWsZn7mehH8BI=; h=From:To:Cc:Subject:Date:From; b=mU0CSDIRLU770cVTc7mGdG67gRacbfHX7KZ3Gwz+oYUJEhalcsfOL6Vj1uCz2stDU TEripNlxvNFEQP8cntlNdqNLokL4guGK4fJoZy/He1cRDDL3C/hqdGyHfAyL+d//Ue SZ2a68BRNj2MQEEqXEcY/Bx+shnT3i/pQNx7nYcsMyoQYXkga7UNES7HLABgt8Evj2 nGtk08D4xHZacvpGIqT2BnkIEG6gYleBhqPN4en9XoJgu06FVwBgAUzAhdsQw/HaVA fWJd4prZaGkIOdq20udzo8rEXW9StEHeOO2+21CdEQGxMjCQhfMTho3yWZS2G8d1A+ 1Y0kbZ0DQGXmA== From: Jarkko Sakkinen To: linux-integrity@vger.kernel.org Cc: keyrings@vger.kernel.org, David Woodhouse , Eric Biggers , James Bottomley , Jarkko Sakkinen , Herbert Xu , "David S. Miller" , Andrew Morton , James Bottomley , Mimi Zohar , David Howells , Paul Moore , James Morris , "Serge E. Hallyn" , linux-crypto@vger.kernel.org (open list:CRYPTO API), linux-kernel@vger.kernel.org (open list), linux-security-module@vger.kernel.org (open list:SECURITY SUBSYSTEM) Subject: [PATCH v2] KEYS: trusted: Use ASN.1 encoded OID Date: Thu, 23 May 2024 16:23:37 +0300 Message-ID: <20240523132341.32092-1-jarkko@kernel.org> X-Mailer: git-send-email 2.45.1 Precedence: bulk X-Mailing-List: keyrings@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 There's no reason to encode OID_TPMSealedData at run-time, as it never changes. Replace it with the encoded version, which has exactly the same size: 67 81 05 0A 01 05 Include OBJECT IDENTIFIER (0x06) tag and length as the epilogue so that the OID can be simply copied to the blob. Signed-off-by: Jarkko Sakkinen Reviewed-by: David Howells --- v2: * Not my day I guess. This one has print_hex_dump() taken away. Apologies for spamming. The patch is however tested properly with run-tests.sh in https://gitlab.com/jarkkojs/linux-tpmdd-test. --- include/linux/asn1_encoder.h | 4 - lib/asn1_encoder.c | 91 ----------------------- security/keys/trusted-keys/trusted_tpm2.c | 7 +- 3 files changed, 4 insertions(+), 98 deletions(-) diff --git a/include/linux/asn1_encoder.h b/include/linux/asn1_encoder.h index 08cd0c2ad34f..afeefdfe2525 100644 --- a/include/linux/asn1_encoder.h +++ b/include/linux/asn1_encoder.h @@ -8,14 +8,10 @@ #include #include -#define asn1_oid_len(oid) (sizeof(oid)/sizeof(u32)) unsigned char * asn1_encode_integer(unsigned char *data, const unsigned char *end_data, s64 integer); unsigned char * -asn1_encode_oid(unsigned char *data, const unsigned char *end_data, - u32 oid[], int oid_len); -unsigned char * asn1_encode_tag(unsigned char *data, const unsigned char *end_data, u32 tag, const unsigned char *string, int len); unsigned char * diff --git a/lib/asn1_encoder.c b/lib/asn1_encoder.c index 0fd3c454a468..c0db3cbebe89 100644 --- a/lib/asn1_encoder.c +++ b/lib/asn1_encoder.c @@ -85,97 +85,6 @@ asn1_encode_integer(unsigned char *data, const unsigned char *end_data, } EXPORT_SYMBOL_GPL(asn1_encode_integer); -/* calculate the base 128 digit values setting the top bit of the first octet */ -static int asn1_encode_oid_digit(unsigned char **_data, int *data_len, u32 oid) -{ - unsigned char *data = *_data; - int start = 7 + 7 + 7 + 7; - int ret = 0; - - if (*data_len < 1) - return -EINVAL; - - /* quick case */ - if (oid == 0) { - *data++ = 0x80; - (*data_len)--; - goto out; - } - - while (oid >> start == 0) - start -= 7; - - while (start > 0 && *data_len > 0) { - u8 byte; - - byte = oid >> start; - oid = oid - (byte << start); - start -= 7; - byte |= 0x80; - *data++ = byte; - (*data_len)--; - } - - if (*data_len > 0) { - *data++ = oid; - (*data_len)--; - } else { - ret = -EINVAL; - } - - out: - *_data = data; - return ret; -} - -/** - * asn1_encode_oid() - encode an oid to ASN.1 - * @data: position to begin encoding at - * @end_data: end of data pointer, points one beyond last usable byte in @data - * @oid: array of oids - * @oid_len: length of oid array - * - * this encodes an OID up to ASN.1 when presented as an array of OID values - */ -unsigned char * -asn1_encode_oid(unsigned char *data, const unsigned char *end_data, - u32 oid[], int oid_len) -{ - int data_len = end_data - data; - unsigned char *d = data + 2; - int i, ret; - - if (WARN(oid_len < 2, "OID must have at least two elements")) - return ERR_PTR(-EINVAL); - - if (WARN(oid_len > 32, "OID is too large")) - return ERR_PTR(-EINVAL); - - if (IS_ERR(data)) - return data; - - - /* need at least 3 bytes for tag, length and OID encoding */ - if (data_len < 3) - return ERR_PTR(-EINVAL); - - data[0] = _tag(UNIV, PRIM, OID); - *d++ = oid[0] * 40 + oid[1]; - - data_len -= 3; - - for (i = 2; i < oid_len; i++) { - ret = asn1_encode_oid_digit(&d, &data_len, oid[i]); - if (ret < 0) - return ERR_PTR(ret); - } - - data[1] = d - data - 2; - - return d; -} -EXPORT_SYMBOL_GPL(asn1_encode_oid); - /** * asn1_encode_length() - encode a length to follow an ASN.1 tag * @data: pointer to encode at diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c index 8b7dd73d94c1..4a2b4ad5a913 100644 --- a/security/keys/trusted-keys/trusted_tpm2.c +++ b/security/keys/trusted-keys/trusted_tpm2.c @@ -26,7 +26,8 @@ static struct tpm2_hash tpm2_hash_map[] = { {HASH_ALGO_SM3_256, TPM_ALG_SM3_256}, }; -static u32 tpm2key_oid[] = { 2, 23, 133, 10, 1, 5 }; +/* Encoded OID_TPMSealedData. */ +static u8 OID_TPMSealedData_ASN1[] = {0x06, 0x06, 0x67, 0x81, 0x05, 0x0a, 0x01, 0x05}; static int tpm2_key_encode(struct trusted_key_payload *payload, struct trusted_key_options *options, @@ -51,8 +52,8 @@ static int tpm2_key_encode(struct trusted_key_payload *payload, if (!scratch) return -ENOMEM; - work = asn1_encode_oid(work, end_work, tpm2key_oid, - asn1_oid_len(tpm2key_oid)); + work = memcpy(work, OID_TPMSealedData_ASN1, sizeof(OID_TPMSealedData_ASN1)); + work += sizeof(OID_TPMSealedData_ASN1); if (options->blobauth_len == 0) { unsigned char bool[3], *w = bool;