PGPLIB: PGP definitions (RFC 4880)

hulk inclusion
category: feature
feature: IMA Digest Lists extension
bugzilla: 46797

-------------------------------------------------

Provide some useful PGP definitions from RFC 4880.  These describe details
of public key crypto as used by crypto keys for things like signature
verification.

Changelog:

v0:
- fix style issues (Roberto Sassu)
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Co-developed-by: NRoberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: NRoberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: NTianxing Zhang <zhangtianxing3@huawei.com>
Reviewed-by: NJason Yan <yanaijie@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

include/linux/pgp.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/* PGP definitions (RFC 4880)
+ *
+ * Copyright (C) 2011 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#ifndef _LINUX_PGP_H
+#define _LINUX_PGP_H
+
+#include <linux/types.h>
+
+struct pgp_key_ID {
+	u8 id[8];
+} __packed;
+
+struct pgp_time {
+	u8 time[4];
+} __packed;
+
+/*
+ * PGP public-key algorithm identifiers [RFC4880: 9.1]
+ */
+enum pgp_pubkey_algo {
+	PGP_PUBKEY_RSA_ENC_OR_SIG	= 1,
+	PGP_PUBKEY_RSA_ENC_ONLY		= 2,
+	PGP_PUBKEY_RSA_SIG_ONLY		= 3,
+	PGP_PUBKEY_ELGAMAL		= 16,
+	PGP_PUBKEY_DSA			= 17,
+	PGP_PUBKEY__LAST
+};
+
+/*
+ * PGP symmetric-key algorithm identifiers [RFC4880: 9.2]
+ */
+enum pgp_symkey_algo {
+	PGP_SYMKEY_PLAINTEXT		= 0,
+	PGP_SYMKEY_IDEA			= 1,
+	PGP_SYMKEY_3DES			= 2,
+	PGP_SYMKEY_CAST5		= 3,
+	PGP_SYMKEY_BLOWFISH		= 4,
+	PGP_SYMKEY_AES_128KEY		= 7,
+	PGP_SYMKEY_AES_192KEY		= 8,
+	PGP_SYMKEY_AES_256KEY		= 9,
+	PGP_SYMKEY_TWOFISH_256KEY	= 10,
+};
+
+/*
+ * PGP compression algorithm identifiers [RFC4880: 9.3]
+ */
+enum pgp_compr_algo {
+	PGP_COMPR_UNCOMPRESSED		= 0,
+	PGP_COMPR_ZIP			= 1,
+	PGP_COMPR_ZLIB			= 2,
+	PGP_COMPR_BZIP2			= 3,
+};
+
+/*
+ * PGP hash algorithm identifiers [RFC4880: 9.4]
+ */
+enum pgp_hash_algo {
+	PGP_HASH_MD5			= 1,
+	PGP_HASH_SHA1			= 2,
+	PGP_HASH_RIPE_MD_160		= 3,
+	PGP_HASH_SHA256			= 8,
+	PGP_HASH_SHA384			= 9,
+	PGP_HASH_SHA512			= 10,
+	PGP_HASH_SHA224			= 11,
+	PGP_HASH__LAST
+};
+
+extern const char *const pgp_hash_algorithms[PGP_HASH__LAST];
+
+/*
+ * PGP packet type tags [RFC4880: 4.3].
+ */
+enum pgp_packet_tag {
+	PGP_PKT_RESERVED		= 0,
+	PGP_PKT_PUBKEY_ENC_SESSION_KEY	= 1,
+	PGP_PKT_SIGNATURE		= 2,
+	PGP_PKT_SYMKEY_ENC_SESSION_KEY	= 3,
+	PGP_PKT_ONEPASS_SIGNATURE	= 4,
+	PGP_PKT_SECRET_KEY		= 5,
+	PGP_PKT_PUBLIC_KEY		= 6,
+	PGP_PKT_SECRET_SUBKEY		= 7,
+	PGP_PKT_COMPRESSED_DATA		= 8,
+	PGP_PKT_SYM_ENC_DATA		= 9,
+	PGP_PKT_MARKER			= 10,
+	PGP_PKT_LITERAL_DATA		= 11,
+	PGP_PKT_TRUST			= 12,
+	PGP_PKT_USER_ID			= 13,
+	PGP_PKT_PUBLIC_SUBKEY		= 14,
+	PGP_PKT_USER_ATTRIBUTE		= 17,
+	PGP_PKT_SYM_ENC_AND_INTEG_DATA	= 18,
+	PGP_PKT_MODIFY_DETECT_CODE	= 19,
+	PGP_PKT_PRIVATE_0		= 60,
+	PGP_PKT_PRIVATE_3		= 63,
+	PGP_PKT__HIGHEST		= 63
+};
+
+/*
+ * Signature (tag 2) packet [RFC4880: 5.2].
+ */
+enum pgp_signature_version {
+	PGP_SIG_VERSION_3			= 3,
+	PGP_SIG_VERSION_4			= 4,
+};
+
+enum pgp_signature_type {
+	PGP_SIG_BINARY_DOCUMENT_SIG		= 0x00,
+	PGP_SIG_CANONICAL_TEXT_DOCUMENT_SIG	= 0x01,
+	PGP_SIG_STANDALONE_SIG			= 0x02,
+	PGP_SIG_GENERAL_CERT_OF_UID_PUBKEY	= 0x10,
+	PGP_SIG_PERSONAL_CERT_OF_UID_PUBKEY	= 0x11,
+	PGP_SIG_CASUAL_CERT_OF_UID_PUBKEY	= 0x12,
+	PGP_SIG_POSTITIVE_CERT_OF_UID_PUBKEY	= 0x13,
+	PGP_SIG_SUBKEY_BINDING_SIG		= 0x18,
+	PGP_SIG_PRIMARY_KEY_BINDING_SIG		= 0x19,
+	PGP_SIG_DIRECTLY_ON_KEY			= 0x1F,
+	PGP_SIG_KEY_REVOCATION_SIG		= 0x20,
+	PGP_SIG_SUBKEY_REVOCATION_SIG		= 0x28,
+	PGP_SIG_CERT_REVOCATION_SIG		= 0x30,
+	PGP_SIG_TIMESTAMP_SIG			= 0x40,
+	PGP_SIG_THIRD_PARTY_CONFIRM_SIG		= 0x50,
+};
+
+struct pgp_signature_v3_packet {
+	enum pgp_signature_version version : 8; /* == PGP_SIG_VERSION_3 */
+	u8	length_of_hashed;	/* == 5 */
+	struct {
+		enum pgp_signature_type signature_type : 8;
+		struct pgp_time	creation_time;
+	} __packed hashed;
+	struct pgp_key_ID issuer;
+	enum pgp_pubkey_algo pubkey_algo : 8;
+	enum pgp_hash_algo hash_algo : 8;
+} __packed;
+
+struct pgp_signature_v4_packet {
+	enum pgp_signature_version version : 8;	/* == PGP_SIG_VERSION_4 */
+	enum pgp_signature_type signature_type : 8;
+	enum pgp_pubkey_algo pubkey_algo : 8;
+	enum pgp_hash_algo hash_algo : 8;
+} __packed;
+
+/*
+ * V4 signature subpacket types [RFC4880: 5.2.3.1].
+ */
+enum pgp_sig_subpkt_type {
+	PGP_SIG_CREATION_TIME			= 2,
+	PGP_SIG_EXPIRATION_TIME			= 3,
+	PGP_SIG_EXPORTABLE_CERT			= 4,
+	PGP_SIG_TRUST_SIG			= 5,
+	PGP_SIG_REGEXP				= 6,
+	PGP_SIG_REVOCABLE			= 7,
+	PGP_SIG_KEY_EXPIRATION_TIME		= 9,
+	PGP_SIG_PREF_SYM_ALGO			= 11,
+	PGP_SIG_REVOCATION_KEY			= 12,
+	PGP_SIG_ISSUER				= 16,
+	PGP_SIG_NOTATION_DATA			= 20,
+	PGP_SIG_PREF_HASH_ALGO			= 21,
+	PGP_SIG_PREF_COMPR_ALGO			= 22,
+	PGP_SIG_KEY_SERVER_PREFS		= 23,
+	PGP_SIG_PREF_KEY_SERVER			= 24,
+	PGP_SIG_PRIMARY_USER_ID			= 25,
+	PGP_SIG_POLICY_URI			= 26,
+	PGP_SIG_KEY_FLAGS			= 27,
+	PGP_SIG_SIGNERS_USER_ID			= 28,
+	PGP_SIG_REASON_FOR_REVOCATION		= 29,
+	PGP_SIG_FEATURES			= 30,
+	PGP_SIG_TARGET				= 31,
+	PGP_SIG_EMBEDDED_SIG			= 32,
+	PGP_SIG__LAST
+};
+
+#define PGP_SIG_SUBPKT_TYPE_CRITICAL_MASK	0x80
+
+/*
+ * Key (tag 5, 6, 7 and 14) packet
+ */
+enum pgp_key_version {
+	PGP_KEY_VERSION_2			= 2,
+	PGP_KEY_VERSION_3			= 3,
+	PGP_KEY_VERSION_4			= 4,
+};
+
+struct pgp_key_v3_packet {
+	enum pgp_key_version version : 8;
+	struct pgp_time	creation_time;
+	u8 expiry[2];			/* 0 or time in days till expiry */
+	enum pgp_pubkey_algo pubkey_algo : 8;
+	u8 key_material[0];
+} __packed;
+
+struct pgp_key_v4_packet {
+	enum pgp_key_version version : 8;
+	struct pgp_time	creation_time;
+	enum pgp_pubkey_algo pubkey_algo : 8;
+	u8 key_material[0];
+} __packed;
+
+/*
+ * Literal Data (tag 11) packet
+ */
+enum pgp_literal_data_format {
+	PGP_LIT_FORMAT_BINARY			= 0x62,
+	PGP_LIT_FORMAT_TEXT			= 0x74,
+	PGP_LIT_FORMAT_TEXT_UTF8		= 0x75,
+};
+
+#endif /* _LINUX_PGP_H */