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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-15 17:00:10 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-15 17:00:10 +0000
commit1ebbd027274333758fc3517685d81847601db676 (patch)
tree5259d053d3e3066e0745150805fa4b20184eef98 /magic/Magdir/pgp-binary-keys
parentInitial commit. (diff)
downloadfile-upstream.tar.xz
file-upstream.zip
Adding upstream version 1:5.45.upstream/1%5.45upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'magic/Magdir/pgp-binary-keys')
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diff --git a/magic/Magdir/pgp-binary-keys b/magic/Magdir/pgp-binary-keys
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+
+#------------------------------------------------------------------------------
+# $File: pgp-binary-keys,v 1.2 2021/04/26 15:56:00 christos Exp $
+# pgp-binary-keys: This file handles pgp binary keys.
+#
+# An PGP certificate or message doesn't have a fixed header. Instead,
+# they are sequences of packets:
+#
+# https://tools.ietf.org/html/rfc4880#section-4.3
+#
+# whose order conforms to a grammar:
+#
+# https://tools.ietf.org/html/rfc4880#section-11
+#
+# Happily most packets have a few fields that are constrained, which
+# allow us to fingerprint them with relatively high certainty.
+#
+# A PGP packet is described by a single byte: the so-called CTB. The
+# high-bit is always set. If bit 6 is set, then it is a so-called
+# new-style CTB; if bit 6 is clear, then it is a so-called old-style
+# CTB. Old-style CTBs have only four bits of type information; bits
+# 1-0 are used to describe the length. New-style CTBs have 6 bits of
+# type information.
+#
+# Following the CTB is the packet's length in bytes. If we blindly
+# advance the file cursor by this amount past the end of the length
+# information we come to the next packet.
+#
+# Data Structures
+# ===============
+#
+# New Style CTB
+# -------------
+#
+# https://tools.ietf.org/html/rfc4880#section-4.2.2
+#
+# 76543210
+# ||\----/
+# || tag
+# |always 1
+# always 1
+#
+# Tag bits 7 and 6 set
+# 0 0xC0 -- Reserved - a packet tag MUST NOT have this value
+# 1 0xC1 -- Public-Key Encrypted Session Key Packet
+# 2 0xC2 -- Signature Packet
+# 3 0xC3 -- Symmetric-Key Encrypted Session Key Packet
+# 4 0xC4 -- One-Pass Signature Packet
+# 5 0xC5 -- Secret-Key Packet
+# 6 0xC6 -- Public-Key Packet
+# 7 0xC7 -- Secret-Subkey Packet
+# 8 0xC8 -- Compressed Data Packet
+# 9 0xC9 -- Symmetrically Encrypted Data Packet
+# 10 0xCA -- Marker Packet
+# 11 0xCB -- Literal Data Packet
+# 12 0xCC -- Trust Packet
+# 13 0xCD -- User ID Packet
+# 14 0xCE -- Public-Subkey Packet
+# 17 0xD1 -- User Attribute Packet
+# 18 0xD2 -- Sym. Encrypted and Integrity Protected Data Packet
+# 19 0xD3 -- Modification Detection Code Packet
+# 60 to 63 -- Private or Experimental Values
+#
+# The CTB is followed by the length header, which is densely encoded:
+#
+# if length[0] is:
+# 0..191: one byte length (length[0])
+# 192..223: two byte length ((length[0] - 192) * 256 + length[2] + 192
+# 224..254: four byte length (big endian interpretation of length[1..5])
+# 255: partial body encoding
+#
+# The partial body encoding is similar to HTTP's chunk encoding. It
+# is only allowed for container packets (SEIP, Compressed Data and
+# Literal).
+#
+# Old Style CTB
+# -------------
+#
+# https://tools.ietf.org/html/rfc4880#section-4.2.1
+#
+# CTB:
+#
+# 76543210
+# ||\--/\/
+# || | length encoding
+# || tag
+# |always 0
+# always 1
+#
+# Tag:
+#
+# Tag bit 7 set, bits 6, 1, 0 clear
+# 0 0x80 -- Reserved - a packet tag MUST NOT have this value
+# 1 0x84 -- Public-Key Encrypted Session Key Packet
+# 2 0x88 -- Signature Packet
+# 3 0x8C -- Symmetric-Key Encrypted Session Key Packet
+# 4 0x90 -- One-Pass Signature Packet
+# 5 0x94 -- Secret-Key Packet
+# 6 0x98 -- Public-Key Packet
+# 7 0x9C -- Secret-Subkey Packet
+# 8 0xA0 -- Compressed Data Packet
+# 9 0xA4 -- Symmetrically Encrypted Data Packet
+# 10 0xA8 -- Marker Packet
+# 11 0xAC -- Literal Data Packet
+# 12 0xB0 -- Trust Packet
+# 13 0xB4 -- User ID Packet
+# 14 0xB8 -- Public-Subkey Packet
+#
+# Length encoding:
+#
+# Value
+# 0 1 byte length (following byte is the length)
+# 1 2 byte length (following two bytes are the length)
+# 2 4 byte length (following four bytes are the length)
+# 3 indeterminate length: natural end of packet, e.g., EOF
+#
+# An indeterminate length is only allowed for container packets
+# (SEIP, Compressed Data and Literal).
+#
+# Certificates
+# ------------
+#
+# We check the first three packets to determine if a sequence of
+# OpenPGP packets is likely to be a certificate. The grammar allows
+# the following prefixes:
+#
+# [Primary Key] [SIG] (EOF or another certificate)
+# [Primary Key] [SIG] [User ID] [SIG]...
+# [Primary Key] [SIG] [User Attribute] [SIG]...
+# [Primary Key] [SIG] [Subkey] [SIG]...
+# [Primary Key] [User ID] [SIG]...
+# [Primary Key] [User Attribute] [SIG]...
+# [Primary Key] [Subkey] [SIG]...
+#
+# Any number of marker packets are also allowed between each packet,
+# but they are not normally used and we don't currently check for
+# them.
+#
+# The keys and subkeys may be public or private.
+#
+
+# Key packets and signature packets are versioned. There are two
+# packet versions that we need to worry about in practice: v3 and v4.
+# v4 packets were introduced in RFC 2440, which was published in 1998.
+# It also deprecated v3 packets. There are no actively used v3
+# certificates (GnuPG removed the code to support them in November
+# 2014). But there are v3 keys lying around and it is useful to
+# identify them. The next version of OpenPGP will introduce v5 keys.
+# The document has not yet been standardized so changes are still
+# possible. But, for our purposes, it appears that v5 data structures
+# will be identical to v4 data structures modulo the version number.
+#
+# https://tools.ietf.org/html/rfc2440
+# https://lists.gnupg.org/pipermail/gnupg-announce/2014q4/000358.html
+# https://www.ietf.org/id/draft-ietf-openpgp-rfc4880bis-09.html#name-key-material-packet
+
+
+
+
+# The first packet has to be a public key or a secret key.
+#
+# New-Style Public Key
+0 ubyte =0xC6 OpenPGP Public Key
+>&0 use primary_key_length_new
+# New-Style Secret Key
+0 ubyte =0xC5 OpenPGP Secret Key
+>&0 use primary_key_length_new
+# Old-Style Public Key
+0 ubyte&0xFC =0x98 OpenPGP Public Key
+>&-1 use primary_key_length_old
+# Old-Style Secret Key
+0 ubyte&0xFC =0x94 OpenPGP Secret Key
+>&-1 use primary_key_length_old
+
+# Parse the length, check the packet's body and finally advance to the
+# next packet.
+
+# There are 4 different new-style length encodings, but the partial
+# body encoding is only acceptable for the SEIP, Compressed Data, and
+# Literal packets, which isn't valid for any packets in a certificate
+# so we ignore it.
+0 name primary_key_length_new
+>&0 ubyte <192
+#>>&0 ubyte x (1 byte length encoding, %d bytes)
+>>&0 use pgp_binary_key_pk_check
+>>>&(&-1.B) use sig_or_component_1
+>&0 ubyte >191
+>>&-1 ubyte <225
+# offset = ((offset[0] - 192) << 8) + offset[1] + 192 (for the length header)
+# raw - (192 * 256 - 192)
+# = 48960
+#>>>&0 ubeshort x (2 byte length encoding, %d bytes)
+>>>&1 use pgp_binary_key_pk_check
+>>>>&(&-2.S-48960) use sig_or_component_1
+>&0 ubyte =255
+#>>&0 belong x (5 byte length encoding, %d bytes)
+>>&4 use pgp_binary_key_pk_check
+>>>&(&-4.L) use sig_or_component_1
+# Partial body encoding (only valid for container packets).
+# >&0 ubyte >224
+# >>&0 ubyte <255 partial body encoding
+
+# There are 4 different old-style length encodings, but the
+# indeterminate length encoding is only acceptable for the SEIP,
+# Compressed Data, and Literal packets, which isn't valid for any
+# packets in a certificate.
+0 name primary_key_length_old
+#>&0 ubyte x (ctb: %x)
+>&0 ubyte&0x3 =0
+#>>&0 ubyte x (1 byte length encoding, %d bytes)
+>>&1 use pgp_binary_key_pk_check
+>>>&(&-1.B) use sig_or_component_1
+>&0 ubyte&0x3 =1
+#>>&0 ubeshort x (2 byte length encoding, %d bytes)
+>>&2 use pgp_binary_key_pk_check
+>>>&(&-2.S) use sig_or_component_1
+>&0 ubyte&0x3 =2
+#>>&0 ubelong x (4 byte length encoding, %d bytes)
+>>&4 use pgp_binary_key_pk_check
+>>>&(&-4.L) use sig_or_component_1
+
+# Check the Key.
+#
+# https://tools.ietf.org/html/rfc4880#section-5.5.2
+0 name pgp_binary_key_pk_check
+# Valid versions are: 2, 3, 4. 5 is proposed in RFC 4880bis.
+# Anticipate a v6 / v7 format that like v5 is compatible with v4.
+# key format in a decade or so :D.
+>&0 ubyte >1
+>>&-1 ubyte <8
+>>>&-1 byte x Version %d
+# Check that keys were created after 1990.
+# (1990 - 1970) * 365.2524 * 24 * 60 * 60 = 631156147
+>>>&0 bedate >631156147 \b, Created %s
+>>>>&-5 ubyte >3
+>>>>>&4 use pgp_binary_key_algo
+>>>>&-5 ubyte <4
+>>>>>&6 use pgp_binary_key_algo
+
+# Print out the key's algorithm and the number of bits, if this is
+# relevant (ECC keys are a fixed size).
+0 name pgp_binary_key_algo
+>0 clear x
+>&0 ubyte =1 \b, RSA (Encrypt or Sign,
+>>&0 ubeshort x \b %d bits)
+>&0 ubyte =2 \b, RSA (Encrypt,
+>>&0 ubeshort x \b %d bits)
+>&0 ubyte =3 \b, RSA (Sign,
+>>&0 ubeshort x \b %d bits)
+>&0 ubyte =16 \b, El Gamal (Encrypt,
+>>&0 ubeshort x \b %d bits)
+>&0 ubyte =17 \b, DSA
+>>&0 ubeshort x \b (%d bits)
+>&0 ubyte =18 \b, ECDH
+>&0 ubyte =19 \b, ECDSA
+>&0 ubyte =20 \b, El Gamal (Encrypt or Sign,
+>>&0 ubeshort x \b %d bits)
+>&0 ubyte =22 \b, EdDSA
+>&0 default x
+>>&0 ubyte x \b, Unknown Algorithm (%#x)
+
+# Match all possible second packets.
+0 name sig_or_component_1
+#>0 ubyte x (ctb: %x)
+>&0 ubyte =0xC2
+>>0 ubyte x \b; Signature
+>>&0 use sig_or_component_1_length_new
+>&0 ubyte =0xCD
+>>0 ubyte x \b; User ID
+>>&0 use sig_or_component_1_length_new
+>&0 ubyte =0xCE
+>>0 ubyte x \b; Public Subkey
+>>&0 use sig_or_component_1_length_new
+>&0 ubyte =0xC7
+>>0 ubyte x \b; Secret Subkey
+>>&0 use sig_or_component_1_length_new
+>&0 ubyte =0xD1
+>>0 ubyte x \b; User Attribute
+>>&0 use sig_or_component_1_length_new
+>&0 ubyte&0xFC =0x88
+>>0 ubyte x \b; Signature
+>>&-1 use sig_or_component_1_length_old
+>&0 ubyte&0xFC =0xB4
+>>0 ubyte x \b; User ID
+>>&-1 use sig_or_component_1_length_old
+>&0 ubyte&0xFC =0xB8
+>>0 ubyte x \b; Public Subkey
+>>&-1 use sig_or_component_1_length_old
+>&0 ubyte&0xFC =0x9C
+>>0 ubyte x \b; Secret Subkey
+>>&-1 use sig_or_component_1_length_old
+
+# Copy of 'primary_key_length_new', but calls cert_packet_3.
+0 name sig_or_component_1_length_new
+>&0 ubyte <192
+#>>&0 ubyte x (1 byte new length encoding, %d bytes)
+>>&(&-1.B) use cert_packet_3
+>&0 ubyte >191
+>>&-1 ubyte <225
+# offset = ((offset[0] - 192) << 8) + offset[1] + 192 + 1 (for the length header)
+# raw - (192 * 256 - 192 - 1)
+# = 48959
+#>>>&-1 ubeshort x (2 byte new length encoding, %d bytes)
+>>>&(&-1.S-48959) use cert_packet_3
+>&0 ubyte =255
+#>>&0 belong x (5 byte new length encoding, %d bytes)
+>>&(&-4.L) use cert_packet_3
+# Partial body encoding (only valid for container packets).
+# >&0 ubyte >224
+# >>&0 ubyte <255 partial body encoding
+
+0 name sig_or_component_1_length_old
+#>&0 ubyte x (ctb: %x)
+>&0 ubyte&0x3 =0
+#>>&0 ubyte x (1 byte old length encoding, %d bytes)
+>>&(&0.B+1) use cert_packet_3
+>&0 ubyte&0x3 =1
+#>>&0 ubeshort x (2 byte old length encoding, %d bytes)
+>>&(&0.S+2) use cert_packet_3
+>&0 ubyte&0x3 =2
+#>>&0 ubelong x (4 byte old length encoding, %d bytes)
+>>&(&0.L+4) use cert_packet_3
+
+# Copy of above.
+0 name cert_packet_3
+#>0 ubyte x (ctb: %x)
+>&0 ubyte =0xC2
+>>0 ubyte x \b; Signature
+>>&0 use cert_packet_3_length_new
+>&0 ubyte =0xCD
+>>0 ubyte x \b; User ID
+>>&0 use cert_packet_3_length_new
+>&0 ubyte =0xCE
+>>0 ubyte x \b; Public Subkey
+>>&0 use cert_packet_3_length_new
+>&0 ubyte =0xC7
+>>0 ubyte x \b; Secret Subkey
+>>&0 use cert_packet_3_length_new
+>&0 ubyte =0xD1
+>>0 ubyte x \b; User Attribute
+>>&0 use cert_packet_3_length_new
+>&0 ubyte&0xFC =0x88
+>>0 ubyte x \b; Signature
+>>&-1 use cert_packet_3_length_old
+>&0 ubyte&0xFC =0xB4
+>>0 ubyte x \b; User ID
+>>&-1 use cert_packet_3_length_old
+>&0 ubyte&0xFC =0xB8
+>>0 ubyte x \b; Public Subkey
+>>&-1 use cert_packet_3_length_old
+>&0 ubyte&0xFC =0x9C
+>>0 ubyte x \b; Secret Subkey
+>>&-1 use cert_packet_3_length_old
+
+# Copy of above.
+0 name cert_packet_3_length_new
+>&0 ubyte <192
+#>>&0 ubyte x (1 byte new length encoding, %d bytes)
+>>&(&-1.B) use pgp_binary_keys_end
+>&0 ubyte >191
+>>&-1 ubyte <225
+# offset = ((offset[0] - 192) << 8) + offset[1] + 192 + 1 (for the length header)
+# raw - (192 * 256 - 192 - 1)
+# = 48959
+#>>>&-1 ubeshort x (2 byte new length encoding, %d bytes)
+>>>&(&-1.S-48959) use pgp_binary_keys_end
+>&0 ubyte =255
+#>>&0 belong x (5 byte new length encoding, %d bytes)
+>>&(&-4.L) use pgp_binary_keys_end
+
+0 name cert_packet_3_length_old
+#>&0 ubyte x (ctb: %x)
+>&0 ubyte&0x3 =0
+#>>&0 ubyte x (1 byte old length encoding, %d bytes)
+>>&(&0.B+1) use pgp_binary_keys_end
+>&0 ubyte&0x3 =1
+#>>&0 ubeshort x (2 byte old length encoding, %d bytes)
+>>&(&0.S+2) use pgp_binary_keys_end
+>&0 ubyte&0x3 =2
+#>>&0 ubelong x (4 byte old length encoding, %d bytes)
+>>&(&0.L+4) use pgp_binary_keys_end
+
+# We managed to parse the first three packets of the certificate. Declare
+# victory.
+0 name pgp_binary_keys_end
+>0 byte x \b; OpenPGP Certificate
+!:mime application/pgp-keys
+!:ext pgp/gpg/pkr/asd