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| -rw-r--r-- | g13/keyblob.h | 162 |
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diff --git a/g13/keyblob.h b/g13/keyblob.h new file mode 100644 index 0000000..90fcf60 --- /dev/null +++ b/g13/keyblob.h @@ -0,0 +1,162 @@ +/* keyblob.h - Defs to describe a keyblob + * Copyright (C) 2009 Free Software Foundation, Inc. + * + * This file is part of GnuPG. + * + * GnuPG is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 3 of the License, or + * (at your option) any later version. + * + * GnuPG is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <https://www.gnu.org/licenses/>. + */ + +#ifndef G13_KEYBLOB_H +#define G13_KEYBLOB_H + +/* The setup area (header block) is the actual core of G13. Here is + the format: + + u8 Packet type. Value is 61 (0x3d). + u8 Constant value 255 (0xff). + u32 Length of the following structure + b10 Value: "GnuPG/G13\x00". + u8 Version. Value is 1. + u8 reserved + u8 reserved + u8 OS Flag: 0 = unspecified, 1 = Linux + u32 Length of the entire header. This includes all bytes + starting at the packet type and ending with the last + padding byte of the header. + u8 Number of copies of this header (1..255). + u8 Number of copies of this header at the end of the + container (usually 0). + b6 reserved + n bytes: OpenPGP encrypted and optionally signed keyblob. + n bytes: CMS encrypted and optionally signed keyblob. Such a CMS + packet will be enclosed in a private flagged OpenPGP + packet. Either the OpenPGP encrypted packet as described + above, the CMS encrypted or both packets must exist. The + encapsulation packet has this structure: + u8 Packet type. Value is 61 (0x3d). + u8 Constant value 255 (0xff). + u32 Length of the following structure + b10 Value: "GnuPG/CMS\x00". + b(n) Regular CMS structure. + n bytes: Padding. The structure resembles an OpenPGP packet. + u8 Packet type. Value is 61 (0x3d). + u8 Constant value 255 (0xff). + u32 Length of the following structure + b10 Value: "GnuPG/PAD\x00". + b(n) Padding stuff. + (repeat the above value + or if the remaining N < 10, all 0x00). + Given this structure the minimum padding is 16 bytes. + + n bytes: File system container. + (optionally followed by copies on the header). +*/ + + +#define KEYBLOB_TAG_BLOBVERSION 0 +/* This tag is used to describe the version of the keyblob. It must + be the first tag in a keyblob and may only occur once. Its value + is a single byte giving the blob version. The only defined version + is 1. */ + +#define KEYBLOB_TAG_CONTTYPE 1 +/* This tag gives the type of the container. The value is a two byte + big endian integer giving the type of the container as described by + the CONTTYPE_ constants. */ + +#define KEYBLOB_TAG_DETACHED 2 +/* Indicates that the actual storage is not in the same file as the + keyblob. If a value is given it is expected to be the GUID of the + partition. */ + +#define KEYBLOB_TAG_CREATED 3 +/* This is an ISO 8601 time string with the date the container was + created. */ + +#define KEYBLOB_TAG_CONT_NSEC 7 +/* Number of 512-byte sectors of the entire container including all + copies of the setup area. */ + +#define KEYBLOB_TAG_ENC_NSEC 8 +#define KEYBLOB_TAG_ENC_OFF 9 +/* Number of 512-byte sectors used for the encrypted data and its + start offset in 512-byte sectors from the begin of the container. + Note that these information can also be deduced from the + unencrypted part of the setup area. */ + +#define KEYBLOB_TAG_ALGOSTR 10 +/* For a dm-crypt container this is the used algorithm string. For + example: "aes-cbc-essiv:sha256". */ + +#define KEYBLOB_TAG_KEYNO 16 +/* This tag indicates a new key. The value is a 4 byte big endian + integer giving the key number. If the container type does only + need one key this key number should be 0. */ + +#define KEYBLOB_TAG_ENCALGO 17 +/* Describes the algorithm of the key. It must follow a KEYNO tag. + The value is a 2 byte big endian algorithm number. The algorithm + numbers used are those from Libgcrypt (e.g. AES 128 is described by + the value 7). This tag is optional. */ + +#define KEYBLOB_TAG_ENCKEY 18 +/* This tag gives the actual encryption key. It must follow a KEYNO + tag. The value is the plain key. */ + +#define KEYBLOB_TAG_MACALGO 19 +/* Describes the MAC algorithm. It must follow a KEYNO tag. The + value is a 2 byte big endian algorithm number describing the MAC + algorithm with a value of 1 indicating HMAC. It is followed by + data specific to the MAC algorithm. In case of HMAC this data is a + 2 byte big endian integer with the Libgcrypt algorithm id of the + hash algorithm. */ + +#define KEYBLOB_TAG_MACKEY 20 +/* This tag gives the actual MACing key. It must follow a KEYNO tag. + The value is the key used for MACing. */ + + +#define KEYBLOB_TAG_HDRCOPY 21 +/* The value of this tag is a copy of the setup area prefix header + block (packet 61 with marker "GnuPG/G13\x00". We use it to allow + signing of that cleartext data. */ + +#define KEYBLOB_TAG_FILLER 0xffff +/* This tag may be used for alignment and padding purposes. The value + has no meaning. */ + + + +#define CONTTYPE_ENCFS 1 +/* A EncFS based backend. This requires a whole directory which + includes the encrypted files. Metadata is not encrypted. */ + +#define CONTTYPE_DM_CRYPT 2 +/* A DM-Crypt based backend. */ + + +#define CONTTYPE_TRUECRYPT 21571 +/* A Truecrypt (www.truecrypt.org) based container. Due to the design + of truecrypt this requires a second datafile because it is not + possible to prepend a truecrypt container with our keyblob. */ + + + +/*-- keyblob.c --*/ +gpg_error_t g13_is_container (ctrl_t ctrl, const char *filename); +gpg_error_t g13_keyblob_read (const char *filename, + void **r_enckeyblob, size_t *r_enckeybloblen); + + +#endif /*G13_KEYBLOB_H*/ |