1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
|
/*
* Copyright (C) 2009 Martin Willi
* Hochschule fuer Technik Rapperswil
*
* This program 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 2 of the License, or (at your
* option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
*
* This program 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.
*/
#include "pgp_utils.h"
#include <utils/debug.h>
ENUM_BEGIN(pgp_pubkey_alg_names, PGP_PUBKEY_ALG_RSA, PGP_PUBKEY_ALG_RSA_SIGN_ONLY,
"RSA",
"RSA_ENC_ONLY",
"RSA_SIGN_ONLY"
);
ENUM_NEXT(pgp_pubkey_alg_names, PGP_PUBKEY_ALG_ELGAMAL_ENC_ONLY, PGP_PUBKEY_ALG_DIFFIE_HELLMAN, PGP_PUBKEY_ALG_RSA_SIGN_ONLY,
"ELGAMAL_ENC_ONLY",
"DSA",
"ECC",
"ECDSA",
"ELGAMAL",
"DIFFIE_HELLMAN"
);
ENUM_END(pgp_pubkey_alg_names, PGP_PUBKEY_ALG_DIFFIE_HELLMAN);
ENUM(pgp_sym_alg_names, PGP_SYM_ALG_PLAIN, PGP_SYM_ALG_TWOFISH,
"PLAINTEXT",
"IDEA",
"3DES",
"CAST5",
"BLOWFISH",
"SAFER",
"DES",
"AES_128",
"AES_192",
"AES_256",
"TWOFISH"
);
ENUM_BEGIN(pgp_packet_tag_names, PGP_PKT_RESERVED, PGP_PKT_PUBLIC_SUBKEY,
"Reserved",
"Public-Key Encrypted Session Key Packet",
"Signature Packet",
"Symmetric-Key Encrypted Session Key Packet",
"One-Pass Signature Packet",
"Secret Key Packet",
"Public Key Packet",
"Secret Subkey Packet",
"Compressed Data Packet",
"Symmetrically Encrypted Data Packet",
"Marker Packet",
"Literal Data Packet",
"Trust Packet",
"User ID Packet",
"Public Subkey Packet"
);
ENUM_NEXT(pgp_packet_tag_names, PGP_PKT_USER_ATTRIBUTE, PGP_PKT_MOD_DETECT_CODE, PGP_PKT_PUBLIC_SUBKEY,
"User Attribute Packet",
"Sym. Encrypted and Integrity Protected Data Packet",
"Modification Detection Code Packet"
);
ENUM_END(pgp_packet_tag_names, PGP_PKT_MOD_DETECT_CODE);
/**
* Read a PGP scalar of bytes length, advance blob
*/
bool pgp_read_scalar(chunk_t *blob, size_t bytes, uint32_t *scalar)
{
uint32_t res = 0;
if (bytes > blob->len)
{
DBG1(DBG_ASN, "PGP data too short to read %d byte scalar", bytes);
return FALSE;
}
while (bytes-- > 0)
{
res = 256 * res + blob->ptr[0];
*blob = chunk_skip(*blob, 1);
}
*scalar = res;
return TRUE;
}
/**
* Read a PGP MPI, advance blob
*/
bool pgp_read_mpi(chunk_t *blob, chunk_t *mpi)
{
uint32_t bits, bytes;
if (!pgp_read_scalar(blob, 2, &bits))
{
DBG1(DBG_ASN, "PGP data too short to read MPI length");
return FALSE;
}
bytes = (bits + 7) / 8;
if (bytes > blob->len)
{
DBG1(DBG_ASN, "PGP data too short to read %d byte MPI", bytes);
return FALSE;
}
*mpi = chunk_create(blob->ptr, bytes);
*blob = chunk_skip(*blob, bytes);
return TRUE;
}
/**
* Read length of an PGP old packet length encoding
*/
static bool pgp_old_packet_length(chunk_t *blob, uint32_t *length)
{
/* bits 0 and 1 define the packet length type */
u_char type;
if (!blob->len)
{
return FALSE;
}
type = 0x03 & blob->ptr[0];
*blob = chunk_skip(*blob, 1);
if (type > 2)
{
return FALSE;
}
return pgp_read_scalar(blob, type == 0 ? 1 : type * 2, length);
}
/**
* See header.
*/
bool pgp_read_packet(chunk_t *blob, chunk_t *data, pgp_packet_tag_t *tag)
{
uint32_t len;
u_char t;
if (!blob->len)
{
DBG1(DBG_ASN, "missing input");
return FALSE;
}
t = blob->ptr[0];
/* bit 7 must be set */
if (!(t & 0x80))
{
DBG1(DBG_ASN, "invalid packet tag");
return FALSE;
}
/* bit 6 set defines new packet format */
if (t & 0x40)
{
DBG1(DBG_ASN, "new PGP packet format not supported");
return FALSE;
}
t = (t & 0x3C) >> 2;
if (!pgp_old_packet_length(blob, &len) || len > blob->len)
{
DBG1(DBG_ASN, "invalid packet length");
return FALSE;
}
*data = chunk_create(blob->ptr, len);
*blob = chunk_skip(*blob, len);
*tag = t;
DBG2(DBG_ASN, "L1 - PGP %N (%u bytes)", pgp_packet_tag_names, t, len);
DBG3(DBG_ASN, "%B", data);
return TRUE;
}
|
