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Moved generic PGP parsing functions to pgp_utils.[ch]

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This commit is contained in:
Martin Willi
2009-09-15 08:23:47 +02:00
parent 622e558cb0
commit 88f3ffa1b1
4 changed files with 336 additions and 175 deletions
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src/libstrongswan/plugins/pgp/Makefile.am
+1
View File
@@ -6,6 +6,7 @@ AM_CFLAGS = -rdynamic
plugin_LTLIBRARIES = libstrongswan-pgp.la
libstrongswan_pgp_la_SOURCES = pgp_plugin.h pgp_plugin.c \
pgp_utils.h pgp_utils.c \
pgp_encoder.h pgp_encoder.c \
pgp_builder.h pgp_builder.c
src/libstrongswan/plugins/pgp/pgp_builder.c
+27 -175
View File
@@ -15,141 +15,12 @@
*/
#include "pgp_builder.h"
#include "pgp_utils.h"
#include <enum.h>
#include <debug.h>
#include <credentials/keys/private_key.h>
typedef enum pgp_pubkey_alg_t pgp_pubkey_alg_t;
typedef enum pgp_sym_alg_t pgp_sym_alg_t;
/**
* OpenPGP public key algorithms as defined in section 9.1 of RFC 4880
*/
enum pgp_pubkey_alg_t {
PGP_PUBKEY_ALG_RSA = 1,
PGP_PUBKEY_ALG_RSA_ENC_ONLY = 2,
PGP_PUBKEY_ALG_RSA_SIGN_ONLY = 3,
PGP_PUBKEY_ALG_ELGAMAL_ENC_ONLY = 16,
PGP_PUBKEY_ALG_DSA = 17,
PGP_PUBKEY_ALG_ECC = 18,
PGP_PUBKEY_ALG_ECDSA = 19,
PGP_PUBKEY_ALG_ELGAMAL = 20,
PGP_PUBKEY_ALG_DIFFIE_HELLMAN = 21,
};
/**
* OpenPGP symmetric key algorithms as defined in section 9.2 of RFC 4880
*/
enum pgp_sym_alg_t {
PGP_SYM_ALG_PLAIN = 0,
PGP_SYM_ALG_IDEA = 1,
PGP_SYM_ALG_3DES = 2,
PGP_SYM_ALG_CAST5 = 3,
PGP_SYM_ALG_BLOWFISH = 4,
PGP_SYM_ALG_SAFER = 5,
PGP_SYM_ALG_DES = 6,
PGP_SYM_ALG_AES_128 = 7,
PGP_SYM_ALG_AES_192 = 8,
PGP_SYM_ALG_AES_256 = 9,
PGP_SYM_ALG_TWOFISH = 10
};
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"
);
/**
* Read a PGP scalar of bytes length, advance blob
*/
static bool read_scalar(chunk_t *blob, size_t bytes, u_int32_t *scalar)
{
u_int32_t res = 0;
if (bytes > blob->len)
{
DBG1("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 length of an PGP old packet length encoding
*/
static bool old_packet_length(chunk_t *blob, u_int32_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 read_scalar(blob, type == 0 ? 1 : type * 2, length);
}
/**
* Read a PGP MPI, advance blob
*/
static bool read_mpi(chunk_t *blob, chunk_t *mpi)
{
u_int32_t bits, bytes;
if (!read_scalar(blob, 2, &bits))
{
DBG1("PGP data too short to read MPI length");
return FALSE;
}
bytes = (bits + 7) / 8;
if (bytes > blob->len)
{
DBG1("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;
}
/**
* Load a generic public key from a PGP packet
*/
@@ -158,7 +29,7 @@ static public_key_t *parse_public_key(chunk_t blob)
u_int32_t alg;
public_key_t *key;
if (!read_scalar(&blob, 1, &alg))
if (!pgp_read_scalar(&blob, 1, &alg))
{
return NULL;
}
@@ -187,7 +58,7 @@ static public_key_t *parse_rsa_public_key(chunk_t blob)
for (i = 0; i < 2; i++)
{
if (!read_mpi(&blob, &mpi[i]))
if (!pgp_read_mpi(&blob, &mpi[i]))
{
return NULL;
}
@@ -208,12 +79,12 @@ static private_key_t *parse_rsa_private_key(chunk_t blob)
for (i = 0; i < 2; i++)
{
if (!read_mpi(&blob, &mpi[i]))
if (!pgp_read_mpi(&blob, &mpi[i]))
{
return NULL;
}
}
if (!read_scalar(&blob, 1, &s2k))
if (!pgp_read_scalar(&blob, 1, &s2k))
{
return NULL;
}
@@ -230,7 +101,7 @@ static private_key_t *parse_rsa_private_key(chunk_t blob)
for (i = 2; i < 6; i++)
{
if (!read_mpi(&blob, &mpi[i]))
if (!pgp_read_mpi(&blob, &mpi[i]))
{
return NULL;
}
@@ -270,56 +141,37 @@ static bool decrypt_not_allowed(private_key_t *this,
static private_key_t *parse_private_key(chunk_t blob)
{
chunk_t packet;
u_char tag, type;
u_int32_t len, version, created, days, alg;
pgp_packet_tag_t tag;
u_int32_t version, created, days, alg;
private_key_t *key;
tag = blob.ptr[0];
/* bit 7 must be set */
if (!(tag & 0x80))
{
DBG1("invalid packet tag");
return NULL;
}
/* bit 6 set defines new packet format */
if (tag & 0x40)
{
DBG1("new PGP packet format not supported");
return NULL;
}
type = (tag & 0x3C) >> 2;
if (!old_packet_length(&blob, &len) || len > blob.len)
{
DBG1("invalid packet length");
return NULL;
}
packet.len = len;
packet.ptr = blob.ptr;
blob = chunk_skip(blob, len);
if (!read_scalar(&packet, 1, &version))
if (!pgp_read_packet(&blob, &packet, &tag))
{
return NULL;
}
if (version < 3 || version > 4)
if (!pgp_read_scalar(&packet, 1, &version))
{
DBG1("OpenPGP packet version V%d not supported", version);
return NULL;
return FALSE;
}
if (!read_scalar(&packet, 4, &created))
switch (version)
{
case 3:
if (!pgp_read_scalar(&packet, 2, &days))
{
return NULL;
}
break;
case 4:
break;
default:
DBG1("PGP packet version V%d not supported", version);
return FALSE;
}
if (!pgp_read_scalar(&packet, 4, &created))
{
return NULL;
}
if (version == 3)
{
if (!read_scalar(&packet, 2, &days))
{
return NULL;
}
}
if (!read_scalar(&packet, 1, &alg))
if (!pgp_read_scalar(&packet, 1, &alg))
{
return NULL;
}
src/libstrongswan/plugins/pgp/pgp_utils.c
+178
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@@ -0,0 +1,178 @@
/*
* 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 <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, u_int32_t *scalar)
{
u_int32_t res = 0;
if (bytes > blob->len)
{
DBG1("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)
{
u_int32_t bits, bytes;
if (!pgp_read_scalar(blob, 2, &bits))
{
DBG1("PGP data too short to read MPI length");
return FALSE;
}
bytes = (bits + 7) / 8;
if (bytes > blob->len)
{
DBG1("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, u_int32_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)
{
u_int32_t len;
u_char t;
if (!blob->len)
{
DBG1("missing input");
return FALSE;
}
t = blob->ptr[0];
/* bit 7 must be set */
if (!(t & 0x80))
{
DBG1("invalid packet tag");
return FALSE;
}
/* bit 6 set defines new packet format */
if (t & 0x40)
{
DBG1("new PGP packet format not supported");
return FALSE;
}
t = (t & 0x3C) >> 2;
if (!pgp_old_packet_length(blob, &len) || len > blob->len)
{
DBG1("invalid packet length");
return FALSE;
}
*data = chunk_create(blob->ptr, len);
*blob = chunk_skip(*blob, len);
*tag = t;
return TRUE;
}
src/libstrongswan/plugins/pgp/pgp_utils.h
+130
View File
@@ -0,0 +1,130 @@
/*
* 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.
*/
/**
* @defgroup pgp_utils pgp_utils
* @{ @ingroup pgp
*/
#ifndef PGP_UTILS_H_
#define PGP_UTILS_H_
#include <library.h>
typedef enum pgp_pubkey_alg_t pgp_pubkey_alg_t;
typedef enum pgp_sym_alg_t pgp_sym_alg_t;
typedef enum pgp_packet_tag_t pgp_packet_tag_t;
/**
* OpenPGP public key algorithms as defined in section 9.1 of RFC 4880
*/
enum pgp_pubkey_alg_t {
PGP_PUBKEY_ALG_RSA = 1,
PGP_PUBKEY_ALG_RSA_ENC_ONLY = 2,
PGP_PUBKEY_ALG_RSA_SIGN_ONLY = 3,
PGP_PUBKEY_ALG_ELGAMAL_ENC_ONLY = 16,
PGP_PUBKEY_ALG_DSA = 17,
PGP_PUBKEY_ALG_ECC = 18,
PGP_PUBKEY_ALG_ECDSA = 19,
PGP_PUBKEY_ALG_ELGAMAL = 20,
PGP_PUBKEY_ALG_DIFFIE_HELLMAN = 21,
};
/**
* Enum names of pgp_pubkey_alg_t
*/
extern enum_name_t *pgp_pubkey_alg_names;
/**
* OpenPGP symmetric key algorithms as defined in section 9.2 of RFC 4880
*/
enum pgp_sym_alg_t {
PGP_SYM_ALG_PLAIN = 0,
PGP_SYM_ALG_IDEA = 1,
PGP_SYM_ALG_3DES = 2,
PGP_SYM_ALG_CAST5 = 3,
PGP_SYM_ALG_BLOWFISH = 4,
PGP_SYM_ALG_SAFER = 5,
PGP_SYM_ALG_DES = 6,
PGP_SYM_ALG_AES_128 = 7,
PGP_SYM_ALG_AES_192 = 8,
PGP_SYM_ALG_AES_256 = 9,
PGP_SYM_ALG_TWOFISH = 10
};
/**
* Enum names of pgp_sym_alg_t
*/
extern enum_name_t *pgp_sym_alg_names;
/**
* OpenPGP packet tags as defined in section 4.3 of RFC 4880
*/
enum pgp_packet_tag_t {
PGP_PKT_RESERVED = 0,
PGP_PKT_PUBKEY_ENC_SESSION_KEY = 1,
PGP_PKT_SIGNATURE = 2,
PGP_PKT_SYMKEY_ENC_SESSION_KEY = 3,
PGP_PKT_ONE_PASS_SIGNATURE_PKT = 4,
PGP_PKT_SECRET_KEY = 5,
PGP_PKT_PUBLIC_KEY = 6,
PGP_PKT_SECRET_SUBKEY = 7,
PGP_PKT_COMPRESSED_DATA = 8,
PGP_PKT_SYMKEY_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_INT_PROT_DATA = 18,
PGP_PKT_MOD_DETECT_CODE = 19
};
/**
* Enum names of pgp_packet_tag_t
*/
extern enum_name_t *pgp_packet_tag_names;
/**
* Parse a PGP encoded MPI.
*
* @param blob blob to read from, gets advanced
* @param mpi parsed MPI value
* @return TRUE if MPI parsed successfully
*/
bool pgp_read_mpi(chunk_t *blob, chunk_t *mpi);
/**
* Parse a PGP encoded Scalar.
*
* @param blob blob to read from, gets advanced
* @param bytes number of bytes the scalar uses for encoding
* @param scalar resultin scalar
* @return TRUE if scalar parsed successfully
*/
bool pgp_read_scalar(chunk_t *blob, size_t bytes, u_int32_t *scalar);
/**
* Parse a PGP packet.
*
* @param blob blob to read from, gets advanced
* @param data contained packet data
* @param tag tag of the parsed PGP packet
* @return TRUE if packet parsed successfully
*/
bool pgp_read_packet(chunk_t *blob, chunk_t *data, pgp_packet_tag_t *tag);
#endif /* PGP_UTILS_ @}*/