From patchwork Sun Aug 18 16:57:46 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 13767491 Received: from frasgout13.his.huawei.com (frasgout13.his.huawei.com [14.137.139.46]) (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 1AD561422D2; Sun, 18 Aug 2024 17:00:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=14.137.139.46 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724000406; cv=none; b=D+/HGFwb3LnxU7LqVoojIFmqTAMxvIqsY1DGWCh+rFOYYXoFVBtj5ChZRKJ/WDd+GaK3PmV7WnLJt1aBx1CanMQ66+63FQUyctmARTxJgynAxqNT87fnYaFXNMFfytCCHec6onxHj8phRUeHd5MAq1QsYwbv87B75zguY7CJ0OE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724000406; c=relaxed/simple; bh=7YAVB89evGdQ+BUALdIKIojrufVeidrxP0YVKk6wLGc=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=s314hYkGfNULHUA4wu2hkcH6VEb2ibtvpLrr3rOdAXEJXg9x5xcnjWd00erS9vezlukPIl7YM57iH3LbroKeWTvmlhQS3SUvgUayibsdG0Uuz5coU9N/QcjUXi58/aRMlPyndFzV1m2OFMufWhmKs1jRhAEfpgI8JaTrlblSeIo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=14.137.139.46 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.18.186.29]) by frasgout13.his.huawei.com (SkyGuard) with ESMTP id 4Wn1gz1BsNz9v7NK; Mon, 19 Aug 2024 00:41:03 +0800 (CST) Received: from mail02.huawei.com (unknown [7.182.16.47]) by mail.maildlp.com (Postfix) with ESMTP id 0EF97140380; Mon, 19 Aug 2024 00:59:56 +0800 (CST) Received: from huaweicloud.com (unknown [10.204.63.22]) by APP1 (Coremail) with SMTP id LxC2BwAXm4VpKMJm+zZxAQ--.21009S6; Sun, 18 Aug 2024 17:59:55 +0100 (CET) From: Roberto Sassu To: dhowells@redhat.com, dwmw2@infradead.org, herbert@gondor.apana.org.au, davem@davemloft.net Cc: linux-kernel@vger.kernel.org, keyrings@vger.kernel.org, linux-crypto@vger.kernel.org, zohar@linux.ibm.com, linux-integrity@vger.kernel.org, Roberto Sassu Subject: [PATCH v2 04/14] PGPLIB: Basic packet parser Date: Sun, 18 Aug 2024 18:57:46 +0200 Message-Id: <20240818165756.629203-5-roberto.sassu@huaweicloud.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240818165756.629203-1-roberto.sassu@huaweicloud.com> References: <20240818165756.629203-1-roberto.sassu@huaweicloud.com> Precedence: bulk X-Mailing-List: keyrings@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CM-TRANSID: LxC2BwAXm4VpKMJm+zZxAQ--.21009S6 X-Coremail-Antispam: 1UD129KBjvJXoWxtrW7GF1rArW3ZFW5Wr17ZFb_yoWDJrWUpa 48CryrKa1UGwn2krWrAr17WwnrCr48ZFWagayFvw1jk39FgwnYgrZFkFyxKa48Ka1DJ34S krs0gFyYv3Z0qrJanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUPIb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUAV Cq3wA2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0 rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVWUJVWUCwA2z4x0Y4vE2Ix0cI8IcVCY1x0267 AKxVW8JVWxJwA2z4x0Y4vEx4A2jsIE14v26r4j6F4UM28EF7xvwVC2z280aVCY1x0267AK xVW8JVW8Jr1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2 WlYx0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkE bVWUJVW8JwACjcxG0xvY0x0EwIxGrwACI402YVCY1x02628vn2kIc2xKxwCY1x0262kKe7 AKxVWUtVW8ZwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02 F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_Jw0_GF ylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7Cj xVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r 1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x07UZ TmfUUUUU= X-CM-SenderInfo: purev21wro2thvvxqx5xdzvxpfor3voofrz/1tbiAgATBGbBWPgB6gAAs5 From: David Howells Provide a simple parser that extracts the packets from a PGP packet blob and passes the desirous ones to the given processor function: struct pgp_parse_context { u64 types_of_interest; int (*process_packet)(struct pgp_parse_context *context, enum pgp_packet_tag type, u8 headerlen, const u8 *data, size_t datalen); }; int pgp_parse_packets(const u8 *data, size_t datalen, struct pgp_parse_context *ctx); This is configured on with CONFIG_PGP_LIBRARY. Signed-off-by: David Howells Co-developed-by: Roberto Sassu Signed-off-by: Roberto Sassu --- crypto/asymmetric_keys/Kconfig | 6 + crypto/asymmetric_keys/Makefile | 5 + crypto/asymmetric_keys/pgp_library.c | 272 +++++++++++++++++++++++++++ crypto/asymmetric_keys/pgplib.h | 33 ++++ 4 files changed, 316 insertions(+) create mode 100644 crypto/asymmetric_keys/pgp_library.c create mode 100644 crypto/asymmetric_keys/pgplib.h diff --git a/crypto/asymmetric_keys/Kconfig b/crypto/asymmetric_keys/Kconfig index e1345b8f39f1..ce17c0881d94 100644 --- a/crypto/asymmetric_keys/Kconfig +++ b/crypto/asymmetric_keys/Kconfig @@ -103,4 +103,10 @@ config FIPS_SIGNATURE_SELFTEST_ECDSA depends on CRYPTO_SHA256=y || CRYPTO_SHA256=FIPS_SIGNATURE_SELFTEST depends on CRYPTO_ECDSA=y || CRYPTO_ECDSA=FIPS_SIGNATURE_SELFTEST +config PGP_LIBRARY + tristate "PGP parsing library" + help + This option enables a library that provides a number of simple + utility functions for parsing PGP (RFC 4880) packet-based messages. + endif # ASYMMETRIC_KEY_TYPE diff --git a/crypto/asymmetric_keys/Makefile b/crypto/asymmetric_keys/Makefile index bc65d3b98dcb..055b28207111 100644 --- a/crypto/asymmetric_keys/Makefile +++ b/crypto/asymmetric_keys/Makefile @@ -79,3 +79,8 @@ verify_signed_pefile-y := \ $(obj)/mscode_parser.o: $(obj)/mscode.asn1.h $(obj)/mscode.asn1.h $(obj)/mscode.asn1.o: $(obj)/mscode.asn1.c $(obj)/mscode.asn1.h + +# +# PGP handling +# +obj-$(CONFIG_PGP_LIBRARY) += pgp_library.o diff --git a/crypto/asymmetric_keys/pgp_library.c b/crypto/asymmetric_keys/pgp_library.c new file mode 100644 index 000000000000..33ed01f67654 --- /dev/null +++ b/crypto/asymmetric_keys/pgp_library.c @@ -0,0 +1,272 @@ +// SPDX-License-Identifier: GPL-2.0 +/* PGP packet parser (RFC 4880) + * + * Copyright (C) 2011 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#define pr_fmt(fmt) "PGPL: "fmt +#include +#include +#include + +#include "pgplib.h" + +MODULE_LICENSE("GPL"); + +const char *const pgp_hash_algorithms[PGP_HASH__LAST] = { + [PGP_HASH_MD5] = "md5", + [PGP_HASH_SHA1] = "sha1", + [PGP_HASH_RIPE_MD_160] = "rmd160", + [PGP_HASH_SHA256] = "sha256", + [PGP_HASH_SHA384] = "sha384", + [PGP_HASH_SHA512] = "sha512", + [PGP_HASH_SHA224] = "sha224", +}; +EXPORT_SYMBOL_GPL(pgp_hash_algorithms); + +/** + * pgp_parse_packet_header - Parse a PGP packet header + * @_data: Start of the PGP packet (updated to PGP packet data) + * @_datalen: Amount of data remaining in buffer (decreased) + * @_type: Where the packet type will be returned + * @_headerlen: Where the header length will be returned + * + * Parse a set of PGP packet header [RFC 4880: 4.2]. + * + * Return: packet data size on success; non-zero on error. If successful, + * *_data and *_datalen will have been updated and *_headerlen will be set to + * hold the length of the packet header. + */ +static ssize_t pgp_parse_packet_header(const u8 **_data, size_t *_datalen, + enum pgp_packet_tag *_type, + u8 *_headerlen) +{ + enum pgp_packet_tag type; + const u8 *data = *_data; + size_t size, datalen = *_datalen; + + pr_devel("-->%s(,%zu,,)\n", __func__, datalen); + + if (datalen < 2) + goto short_packet; + + pr_devel("pkthdr %02x, %02x\n", data[0], data[1]); + + type = *data++; + datalen--; + if (!(type & 0x80)) { + pr_debug("Packet type does not have MSB set\n"); + return -EBADMSG; + } + type &= ~0x80; + + if (type & 0x40) { + /* New packet length format */ + type &= ~0x40; + pr_devel("new format: t=%u\n", type); + switch (data[0]) { + case 0x00 ... 0xbf: + /* One-byte length */ + size = data[0]; + data++; + datalen--; + *_headerlen = 2; + break; + case 0xc0 ... 0xdf: + /* Two-byte length */ + if (datalen < 2) + goto short_packet; + size = (data[0] - 192) * 256; + size += data[1] + 192; + data += 2; + datalen -= 2; + *_headerlen = 3; + break; + case 0xff: + /* Five-byte length */ + if (datalen < 5) + goto short_packet; + size = data[1] << 24; + size |= data[2] << 16; + size |= data[3] << 8; + size |= data[4]; + data += 5; + datalen -= 5; + *_headerlen = 6; + break; + default: + pr_debug("Partial body length packet not supported\n"); + return -EBADMSG; + } + } else { + /* Old packet length format */ + u8 length_type = type & 0x03; + + type >>= 2; + pr_devel("old format: t=%u lt=%u\n", type, length_type); + + switch (length_type) { + case 0: + /* One-byte length */ + size = data[0]; + data++; + datalen--; + *_headerlen = 2; + break; + case 1: + /* Two-byte length */ + if (datalen < 2) + goto short_packet; + size = data[0] << 8; + size |= data[1]; + data += 2; + datalen -= 2; + *_headerlen = 3; + break; + case 2: + /* Four-byte length */ + if (datalen < 4) + goto short_packet; + size = data[0] << 24; + size |= data[1] << 16; + size |= data[2] << 8; + size |= data[3]; + data += 4; + datalen -= 4; + *_headerlen = 5; + break; + default: + pr_debug("Indefinite length packet not supported\n"); + return -EBADMSG; + } + } + + pr_devel("datalen=%zu size=%zu\n", datalen, size); + if (datalen < size) + goto short_packet; + if (size > INT_MAX) + goto too_big; + + *_data = data; + *_datalen = datalen; + *_type = type; + pr_devel("Found packet type=%u size=%zd\n", type, size); + return size; + +short_packet: + pr_debug("Attempt to parse short packet\n"); + return -EBADMSG; +too_big: + pr_debug("Signature subpacket size >2G\n"); + return -EMSGSIZE; +} + +/** + * pgp_parse_packets - Parse a set of PGP packets + * @data: Data to be parsed (updated) + * @datalen: Amount of data (updated) + * @ctx: Parsing context + * + * Parse a set of PGP packets [RFC 4880: 4]. + * + * Return: 0 on successful parsing, a negative value otherwise + */ +int pgp_parse_packets(const u8 *data, size_t datalen, + struct pgp_parse_context *ctx) +{ + enum pgp_packet_tag type; + ssize_t pktlen; + u8 headerlen; + int ret; + + while (datalen > 2) { + pktlen = pgp_parse_packet_header(&data, &datalen, &type, + &headerlen); + if (pktlen < 0) + return pktlen; + + if ((ctx->types_of_interest >> type) & 1) { + ret = ctx->process_packet(ctx, type, headerlen, + data, pktlen); + if (ret < 0) + return ret; + } + data += pktlen; + datalen -= pktlen; + } + + if (datalen != 0) { + pr_debug("Excess octets in packet stream\n"); + return -EBADMSG; + } + + return 0; +} +EXPORT_SYMBOL_GPL(pgp_parse_packets); + +/** + * pgp_parse_public_key - Parse the common part of a PGP pubkey packet + * @_data: Content of packet (updated) + * @_datalen: Length of packet remaining (updated) + * @pk: Public key data + * + * Parse the common data struct for a PGP pubkey packet [RFC 4880: 5.5.2]. + * + * Return: 0 on successful parsing, a negative value otherwise + */ +int pgp_parse_public_key(const u8 **_data, size_t *_datalen, + struct pgp_parse_pubkey *pk) +{ + const u8 *data = *_data; + size_t datalen = *_datalen; + unsigned int tmp; + + if (datalen < 12) { + pr_debug("Public key packet too short\n"); + return -EBADMSG; + } + + pk->version = *data++; + switch (pk->version) { + case PGP_KEY_VERSION_2: + case PGP_KEY_VERSION_3: + case PGP_KEY_VERSION_4: + break; + default: + pr_debug("Public key packet with unhandled version %d\n", + pk->version); + return -EBADMSG; + } + + tmp = *data++ << 24; + tmp |= *data++ << 16; + tmp |= *data++ << 8; + tmp |= *data++; + pk->creation_time = tmp; + if (pk->version == PGP_KEY_VERSION_4) { + pk->expires_at = 0; /* Have to get it from the selfsignature */ + } else { + unsigned short ndays; + + ndays = *data++ << 8; + ndays |= *data++; + if (ndays) + pk->expires_at = pk->creation_time + ndays * 86400UL; + else + pk->expires_at = 0; + datalen -= 2; + } + + pk->pubkey_algo = *data++; + datalen -= 6; + + pr_devel("%x,%x,%lx,%lx\n", + pk->version, pk->pubkey_algo, pk->creation_time, + pk->expires_at); + + *_data = data; + *_datalen = datalen; + return 0; +} +EXPORT_SYMBOL_GPL(pgp_parse_public_key); diff --git a/crypto/asymmetric_keys/pgplib.h b/crypto/asymmetric_keys/pgplib.h new file mode 100644 index 000000000000..d82b84179433 --- /dev/null +++ b/crypto/asymmetric_keys/pgplib.h @@ -0,0 +1,33 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* PGP library definitions (RFC 4880) + * + * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include "pgp.h" + +/* + * PGP library packet parser + */ +struct pgp_parse_context { + u64 types_of_interest; + int (*process_packet)(struct pgp_parse_context *context, + enum pgp_packet_tag type, + u8 headerlen, + const u8 *data, + size_t datalen); +}; + +extern int pgp_parse_packets(const u8 *data, size_t datalen, + struct pgp_parse_context *ctx); + +struct pgp_parse_pubkey { + enum pgp_key_version version : 8; + enum pgp_pubkey_algo pubkey_algo : 8; + __kernel_old_time_t creation_time; + __kernel_old_time_t expires_at; +}; + +extern int pgp_parse_public_key(const u8 **_data, size_t *_datalen, + struct pgp_parse_pubkey *pk);