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|
/*
File: file_gpg.c
Copyright (C) 2008-2012 Christophe GRENIER <grenier@cgsecurity.org>
This software 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.
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.
You should have received a copy of the GNU General Public License along
with this program; if not, write the Free Software Foundation, Inc., 51
Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#if !defined(SINGLE_FORMAT) || defined(SINGLE_FORMAT_gpg)
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#include <stdio.h>
#include "types.h"
#include "common.h"
#include "filegen.h"
#ifdef DEBUG_GPG
#include "log.h"
#endif
#if defined(__FRAMAC__)
#include "__fc_builtin.h"
#endif
static const char *extension_pgp="pgp";
/*@ requires valid_register_header_check(file_stat); */
static void register_header_check_gpg(file_stat_t *file_stat);
const file_hint_t file_hint_gpg= {
.extension="gpg",
.description="OpenPGP/GPG (Partial support)",
.max_filesize=PHOTOREC_MAX_FILE_SIZE,
.recover=1,
.enable_by_default=1,
.register_header_check=®ister_header_check_gpg
};
/* See rfc4880 OpenPGP Message Format */
/* Public-Key Encrypted Session Key Packets */
#define OPENPGP_TAG_PUBKEY_ENC_SESSION_KEY 1
/* Signature Packet */
#define OPENPGP_TAG_SIGNATURE 2
/* Symmetric-Key Encrypted Session Key Packets */
#define OPENPGP_TAG_SYMKEY_ENC_SESSION_KEY 3
/* One-Pass Signature Packets (Tag 4) */
#define OPENPGP_TAG_ONE_PASS_SIG 4
/* Secret-Key Packet (Tag 5) */
#define OPENPGP_TAG_SEC_KEY 5
/* Public-Key Packet (Tag 6)*/
#define OPENPGP_TAG_PUB_KEY 6
/* Secret-Subkey Packet (Tag 7) */
#define OPENPGP_TAG_SEC_SUBKEY 7
/* Compressed Data Packet (Tag 8) */
/* Symmetrically Encrypted Data Packet */
#define OPENPGP_TAG_SYM_ENC_DATA 9
/* Marker Packet (Tag 10) */
#define OPENPGP_TAG_MARKER 10
/* Literal Data Packet (Tag 11)
* Trust Packet (Tag 12) */
#define OPENPGP_TAG_TRUST 12
/* User ID Packet */
#define OPENPGP_TAG_USER_ID 13
/* Public-Subkey Packet (Tag 14) */
#define OPENPGP_TAG_PUB_SUBKEY 14
/* User Attribute Packet (Tag 17)
*/
/* Sym. Encrypted Integrity Protected Data Packet */
#define OPENPGP_TAG_SYM_ENC_INTEGRITY 18
/* Modification Detection Code Packet (Tag 19) */
static const unsigned char pgp_header[5]= {0xa8, 0x03, 'P', 'G', 'P'};
/*@
@ terminates \true;
@ ensures 0 <= \result <= 0x3f;
@ assigns \nothing;
@*/
static unsigned int openpgp_packet_tag(const unsigned char buf)
{
/* Bit 7 -- Always one */
if((buf&0x80)==0)
return 0; /* Invalid */
return ((buf&0x40)==0?((buf>>2)&0x0f):(buf&0x3f));
}
/*@ requires \valid_read(buf+(0..5));
@ requires \valid(length_type);
@ requires \valid(indeterminate_length);
@ requires \separated(buf+(..), indeterminate_length, length_type);
@ terminates \true;
@ ensures (*length_type == 1) || (*length_type == 2) || (*length_type==3)|| (*length_type==5);
@ assigns *length_type, *indeterminate_length;
*/
static unsigned int old_format_packet_length(const unsigned char *buf, unsigned int *length_type, int *indeterminate_length)
{
/* Old format */
switch(buf[0]&0x3)
{
case 0:
*length_type=2;
return buf[1];
case 1:
*length_type=3;
return (buf[1] << 8) | buf[2];
case 2:
{
const uint32_t *tmp32_ptr=(const uint32_t *)&buf[1];
*length_type=5;
return be32(*tmp32_ptr);
}
default:
*length_type=1;
*indeterminate_length=1;
return 0;
}
}
/*@ requires \valid_read(buf+(0..5));
@ requires \valid(length_type);
@ requires \valid(partial_body_length);
@ requires separation: \separated(buf+(0..5), length_type, partial_body_length);
@ terminates \true;
@ ensures (*length_type == 1) || (*length_type == 2) || (*length_type==5);
@ ensures (*partial_body_length==0) || (*partial_body_length==1);
@ assigns *length_type, *partial_body_length;
*/
static unsigned int new_format_packet_length(const unsigned char *buf, unsigned int *length_type, int *partial_body_length)
{
const unsigned char buf0=buf[0];
*partial_body_length=0;
/* One-Octet Body Length */
if(buf0<=191)
{
*length_type=1;
/*@ assert buf0 <= 191; */
return buf0;
}
/* Two-Octet Body Length */
if(buf0<=223)
{
/*@ assert 192 <= buf0 <= 223; */
unsigned int tmp=buf0;
/*@ assert 192 <= tmp <= 223; */
tmp = ((tmp-192) << 8) + buf[1] + 192;
*length_type=2;
/*@ assert 192 <= tmp <= ((223-192) << 8) + 255 + 192; */
return tmp;
}
/*@ assert 224 <= buf0; */
/* Five-Octet Body Length */
if(buf0==255)
{
const uint32_t *tmp32=(const uint32_t *)&buf[1];
const unsigned int tmp=be32(*tmp32);
*length_type=5;
/*@ assert tmp <= 0xffffffff; */
return tmp;
}
/*@ assert buf0 != 255; */
/*@ assert 224 <= buf0 <= 254; */
{
const unsigned int tmp=buf0&0x1fu;
/*@ assert tmp <= 30; */
const unsigned int tmp2=1u << tmp;
/* Partial Body Lengths */
*length_type=1;
*partial_body_length=1;
/*@ assert tmp2 <= (1<<30); */
return tmp2;
}
}
/*@
@ terminates \true;
@ ensures \result == -1 || 0 <= \result <= 2048;
@ assigns \nothing;
@*/
static int is_valid_mpi(const uint16_t size)
{
const uint16_t tmp=be16(size);
if(tmp <= 16384)
return (tmp+7)/8;
return -1;
}
/*@
@ terminates \true;
@ ensures \result == 0 || \result == 1;
@ assigns \nothing;
@*/
static int is_valid_pubkey_algo(const int algo)
{
/* 1 - RSA (Encrypt or Sign)
* 2 - RSA Encrypt-Only
* 3 - RSA Sign-Only
* 16 - Elgamal (Encrypt-Only), see [ELGAMAL]
* 17 - DSA (Digital Signature Standard)
* 18 - Reserved for Elliptic Curve
* 19 - Reserved for ECDSA
* 20 - Elgamal (Encrypt or Sign)
* 21 - Reserved for Diffie-Hellman (X9.42, as defined for IETF-S/MIME)
* 100 to 110 - Private/Experimental algorithm
*/
switch(algo)
{
case 1:
case 2:
case 3:
case 16:
case 17:
case 20:
return 1;
default:
return 0;
}
}
/*@
@ terminates \true;
@ ensures \result == 0 || \result == 1;
@ assigns \nothing;
@*/
static int is_valid_sym_algo(const int algo)
{
/*
0 - Plaintext or unencrypted data
1 - IDEA [IDEA]
2 - TripleDES (DES-EDE, [SCHNEIER] [HAC] -
168 bit key derived from 192)
3 - CAST5 (128 bit key, as per [RFC2144])
4 - Blowfish (128 bit key, 16 rounds) [BLOWFISH]
5 - Reserved
6 - Reserved
7 - AES with 128-bit key [AES]
8 - AES with 192-bit key
9 - AES with 256-bit key
10 - Twofish with 256-bit key [TWOFISH]
100 to 110 - Private/Experimental algorithm
*/
switch(algo)
{
case 1:
case 2:
case 3:
case 4:
case 7:
case 8:
case 9:
case 10:
return 1;
default:
return 0;
}
}
/*@
@ terminates \true;
@ ensures \result == 0 || \result == 1;
@ assigns \nothing;
@*/
static int is_valid_S2K(const unsigned int algo)
{
/* ID S2K Type
* -- --------
* 0 Simple S2K
* 1 Salted S2K
* 2 Reserved value
* 3 Iterated and Salted S2K
* 100 to 110 Private/Experimental S2K
*/
return (algo==0 || algo==1 || algo==3);
}
/*@
@ requires \valid(handle);
@ requires offset + tmp2 < 0x8000000000000000;
@ requires \separated(handle, &errno, &Frama_C_entropy_source);
@ assigns *handle, errno;
@ assigns Frama_C_entropy_source;
@*/
static unsigned int file_check_gpg_pubkey(FILE *handle, const uint64_t offset, const uint64_t tmp2)
{
int len2;
char buffer[2];
const uint16_t *mpi2_ptr=(uint16_t *)&buffer;
if(my_fseek(handle, offset+tmp2, SEEK_SET) < 0 ||
fread(buffer, sizeof(buffer), 1, handle) != 1)
return 0;
#ifdef __FRAMAC__
Frama_C_make_unknown(&buffer, sizeof(buffer));
#endif
len2=is_valid_mpi(*mpi2_ptr);
#ifdef DEBUG_GPG
log_info(" data: [ %u bits]\n", be16(*mpi2_ptr));
#endif
if(len2 < 0)
return 0;
return len2;
}
/*@
@ requires file_recovery->file_check == &file_check_gpg;
@ requires \separated(file_recovery, file_recovery->handle, file_recovery->extension, &errno, &Frama_C_entropy_source);
@ requires valid_file_check_param(file_recovery);
@ ensures valid_file_check_result(file_recovery);
@ assigns *file_recovery->handle, errno, file_recovery->file_size;
@ assigns Frama_C_entropy_source;
@*/
static void file_check_gpg(file_recovery_t *file_recovery)
{
unsigned int tag=0;
unsigned int nbr=0;
int partial_body_length=0;
int stop=0;
uint64_t offset=0;
const uint64_t org_file_size=file_recovery->file_size;
file_recovery->file_size=0;
/*@
@ loop invariant \separated(file_recovery, file_recovery->handle, file_recovery->extension, &errno, &Frama_C_entropy_source);
@ loop invariant valid_file_recovery(file_recovery);
@ loop assigns *file_recovery->handle, errno, file_recovery->file_size;
@ loop assigns Frama_C_entropy_source;
@ loop assigns tag, nbr, partial_body_length, stop, offset;
@ loop variant 0x7000000000000000 - offset;
@*/
while(stop==0)
{
char sbuffer[32];
const unsigned char *buffer=(const unsigned char *)&sbuffer;
unsigned int i=0;
unsigned int length_type=0;
unsigned int length;
const int old_partial_body_length=partial_body_length;
if(nbr >=0xffffffff || offset >= 0x7000000000000000)
return;
/*@ assert offset < 0x7000000000000000; */
if(my_fseek(file_recovery->handle, offset, SEEK_SET) < 0 ||
fread(&sbuffer, sizeof(sbuffer), 1, file_recovery->handle) != 1)
{
if(nbr>=2 && offset <= org_file_size)
file_recovery->file_size=org_file_size;
return;
}
#ifdef __FRAMAC__
Frama_C_make_unknown(&sbuffer, sizeof(sbuffer));
#endif
if(partial_body_length==0)
{
if((buffer[0]&0x80)==0)
break; /* Invalid */
tag=openpgp_packet_tag(buffer[0]);
if((buffer[0]&0x40)==0)
{
length=old_format_packet_length(&buffer[0], &length_type, &stop);
/*@ assert (length_type == 1) || (length_type == 2) || (length_type==3) || (length_type==5); */
}
else
{
length=new_format_packet_length(&buffer[1], &length_type, &partial_body_length);
length_type++;
/*@ assert (length_type == 2) || (length_type == 3) || (length_type==6); */
}
}
else
{
length=new_format_packet_length(&buffer[0], &length_type, &partial_body_length);
/*@ assert (length_type == 1) || (length_type == 2) || (length_type==5); */
}
/*@ assert 0 <= length_type <= 6; */
#ifdef DEBUG_GPG
log_info("GPG 0x%04x: %02u tag=%2u, size=%u + %u)\n",
0, nbr, tag, length_type, length);
#endif
#if 0
if(tag==0 || tag==15 || (tag>19 && tag!=61)) /* Reserved or unused */
return;
#endif
if(length_type==0)
break; /* Don't know how to find the size */
/*@ assert 0 < length_type <= 6; */
i+=length_type;
/*@ assert 0 < i <= 6; */
offset+=length_type;
if(offset >= 0x7000000000000000)
return ;
/*@ assert offset < 0x7000000000000000; */
/*@ assert length < 0x7000000000000000; */
if(offset + length >= 0x7000000000000000)
return ;
/*@ assert offset + length < 0x7000000000000000; */
if(old_partial_body_length==0)
{
if(tag==OPENPGP_TAG_PUBKEY_ENC_SESSION_KEY)
{
const uint16_t *mpi_ptr=(const uint16_t *)&buffer[i+1+8+1];
const int len=is_valid_mpi(*mpi_ptr);
const int pubkey_algo=buffer[i+1+8];
/* uint8_t version must be 3
* uint64_t pub_key_id
* uint8_t pub_key_algo
* encrypted_session_key */
if(buffer[i]==3 && is_valid_pubkey_algo(pubkey_algo) &&
len>0)
{
/* assert 0 < len <=2048; */
const unsigned int tmp2=1+8+1+2+len;
/* assert 12 < tmp2 <=12+2048; */
#ifdef DEBUG_GPG
log_info("GPG :pubkey enc packet: version %u, algo %u, keyid %02X%02X%02X%02X%02X%02X%02X%02X\n",
buffer[i], pubkey_algo,
buffer[i+1], buffer[i+2], buffer[i+3], buffer[i+4],
buffer[i+5], buffer[i+6], buffer[i+7], buffer[i+8]);
log_info(" data: [ %u bits]\n", be16(*mpi_ptr));
#endif
if(tmp2 > length)
return ;
/*@ assert tmp2 <= length; */
if(pubkey_algo==16 || pubkey_algo==20)
{
const int len2=file_check_gpg_pubkey(file_recovery->handle, offset, tmp2);
if(len2 <= 0)
return;
if((unsigned)(1+8+1+2+len+2+len2) > length)
return;
}
}
else
return;
}
else if(tag==OPENPGP_TAG_SIGNATURE)
{
/* v3 - length=5 */
if(buffer[i]==3 && buffer[i+1]==5 && is_valid_pubkey_algo(buffer[i+1+1+5+8]))
{
#ifdef DEBUG_GPG
log_info(":signature packet: algo %u\n", buffer[i+1+1+5+8]);
log_info(":signature packet: sig_class 0x%02x\n", buffer[i+1+1]);
#endif
}
/* v4 */
else if(buffer[i]==4 && is_valid_pubkey_algo(buffer[i+2]))
{
#ifdef DEBUG_GPG
log_info(":signature packet: algo %u\n", buffer[i+2]);
#endif
}
else
return;
}
else if(tag==OPENPGP_TAG_SYMKEY_ENC_SESSION_KEY)
{
/* v4 */
if(buffer[i]==4 && is_valid_sym_algo(buffer[i+1]) && is_valid_S2K(buffer[i+2]))
{
}
else
return;
}
else if(tag==OPENPGP_TAG_ONE_PASS_SIG)
{
if(buffer[i]==3 && is_valid_sym_algo(buffer[i+1]))
{
}
else
return;
}
else if(tag==OPENPGP_TAG_SYM_ENC_DATA)
{
}
else if(tag==OPENPGP_TAG_MARKER)
{
/* Must be at the beginning of the packet */
if(nbr!=0)
return;
}
else if(tag==OPENPGP_TAG_SYM_ENC_INTEGRITY)
{
#ifdef DEBUG_GPG
log_info("GPG :encrypted data packet:\n");
#endif
/* Version must be 1 */
if(buffer[i]!=1)
return;
}
else if(tag==OPENPGP_TAG_PUB_KEY ||
tag==OPENPGP_TAG_PUB_SUBKEY ||
tag==OPENPGP_TAG_SEC_KEY||
tag==OPENPGP_TAG_SEC_SUBKEY)
{
if((buffer[i]==2 || buffer[i]==3) && is_valid_pubkey_algo(buffer[i+1+4+2]))
{ /* version 2 or 3 */
}
else if(buffer[i]==4 && is_valid_pubkey_algo(buffer[i+1+4]))
{ /* version 4 */
}
else
return;
}
}
if(partial_body_length==0)
nbr++;
offset+=length;
}
if(nbr<2)
return;
file_recovery->file_size=(stop==0?org_file_size:(uint64_t)offset);
}
/*@
@ requires buffer_size >= 23;
@ requires valid_header_check_param(buffer, buffer_size, safe_header_only, file_recovery, file_recovery_new);
@ ensures valid_header_check_result(\result, file_recovery_new);
@ ensures (\result == 1) ==> (file_recovery_new->extension == file_hint_gpg.extension || file_recovery_new->extension == extension_pgp);
@ ensures (\result == 1) ==> (file_recovery_new->time == 0);
@ ensures (\result == 1) ==> (file_recovery_new->file_size == 0);
@ ensures (\result == 1) ==> (file_recovery_new->calculated_file_size == 0);
@ ensures (\result == 1) ==> (file_recovery_new->min_filesize == 0);
@ ensures (\result == 1) ==> (file_recovery_new->data_check == \null);
@ ensures (\result == 1) ==> (file_recovery_new->file_check == &file_check_gpg);
@ ensures (\result == 1) ==> (file_recovery_new->file_rename == \null);
@*/
// X assigns *file_recovery_new;
static int header_check_gpg(const unsigned char *buffer, const unsigned int buffer_size, const unsigned int safe_header_only, const file_recovery_t *file_recovery, file_recovery_t *file_recovery_new)
{
uint64_t i=0;
unsigned int packet_tag[16];
unsigned int nbr=0;
int partial_body_length=0;
int stop=0;
memset(packet_tag, 0, sizeof(packet_tag));
/*@ assert \initialized(packet_tag + (0 .. 15)); */
/*@
@ loop invariant 0 <= nbr <=16;
@ loop assigns i, packet_tag[0..nbr], nbr, partial_body_length, stop;
@ loop variant buffer_size - 23 - i;
@*/
while(nbr<16 && i < buffer_size - 23 && stop==0)
{
/*@ assert 0 <= i < buffer_size - 23; */
unsigned int length_type=0;
unsigned int tag;
unsigned int length;
const int old_partial_body_length=partial_body_length;
if(partial_body_length==0)
{
if((buffer[i]&0x80)==0)
break; /* Invalid */
packet_tag[nbr]=openpgp_packet_tag(buffer[i]);
if((buffer[i]&0x40)==0)
{
length=old_format_packet_length(&buffer[i], &length_type, &stop);
/*@ assert (length_type == 1) || (length_type == 2) || (length_type==3) || (length_type==5); */
}
else
{
length=new_format_packet_length(&buffer[i+1], &length_type, &partial_body_length);
length_type++;
/*@ assert (length_type == 2) || (length_type == 3) || (length_type==6); */
}
}
else
{
length=new_format_packet_length(&buffer[i], &length_type, &partial_body_length);
/*@ assert (length_type == 1) || (length_type == 2) || (length_type==5); */
}
/*@ assert 0 <= length_type <= 6; */
tag=packet_tag[nbr];
#ifdef DEBUG_GPG
log_info("GPG 0x%04lx: %02u tag=%2u, size=%u + %u)\n",
i, nbr, tag, length_type, length);
#endif
#if 0
if(tag==0 || tag==15 || (tag>19 && tag!=61)) /* Reserved or unused */
return 0;
#endif
if(length_type==0)
break; /* Don't know how to find the size */
/*@ assert 0 < length_type <= 6; */
i+=length_type;
/*@ assert 0 <= i < buffer_size - 23 + 6; */
if(old_partial_body_length==0)
{
if(tag==OPENPGP_TAG_PUBKEY_ENC_SESSION_KEY)
{
const uint16_t *mpi_ptr=(const uint16_t *)&buffer[i+1+8+1];
const int len=is_valid_mpi(*mpi_ptr);
/* uint8_t version must be 3
* uint64_t pub_key_id
* uint8_t pub_key_algo
* encrypted_session_key */
if(buffer[i]==3 && is_valid_pubkey_algo(buffer[i+1+8]) &&
len>0)
{
const unsigned int offset_mpi=i+1+8+1+2+len;
#ifdef DEBUG_GPG
log_info("GPG :pubkey enc packet: version %u, algo %u, keyid %02X%02X%02X%02X%02X%02X%02X%02X\n",
buffer[i], buffer[i+1+8],
buffer[i+1], buffer[i+2], buffer[i+3], buffer[i+4],
buffer[i+5], buffer[i+6], buffer[i+7], buffer[i+8]);
log_info(" data: [ %u bits]\n", be16(*mpi_ptr));
#endif
if(offset_mpi +2 > length)
return 0;
if((buffer[i+1+8]==16 || buffer[i+1+8]==20) &&
offset_mpi + 2 <= buffer_size)
{
int len2;
/*@ assert 0 <= offset_mpi + 2 <= buffer_size; */
mpi_ptr=(const uint16_t *)&buffer[offset_mpi];
len2=is_valid_mpi(*mpi_ptr);
#ifdef DEBUG_GPG
log_info(" data: [ %u bits]\n", be16(*mpi_ptr));
#endif
if(len2 <= 0)
return 0;
if((unsigned)(1+8+1+2+len+2+len2) > length)
return 0;
}
}
else
return 0;
}
else if(tag==OPENPGP_TAG_SIGNATURE)
{
/* v3 - length=5 */
if(buffer[i]==3 && buffer[i+1]==5 && is_valid_pubkey_algo(buffer[i+1+1+5+8]))
{
#ifdef DEBUG_GPG
log_info(":signature packet: algo %u\n", buffer[i+1+1+5+8]);
log_info(":signature packet: sig_class 0x%02x\n", buffer[i+1+1]);
#endif
}
/* v4 */
else if(buffer[i]==4 && is_valid_pubkey_algo(buffer[i+2]))
{
#ifdef DEBUG_GPG
log_info(":signature packet: algo %u\n", buffer[i+2]);
#endif
}
else
return 0;
}
else if(tag==OPENPGP_TAG_SYMKEY_ENC_SESSION_KEY)
{
/* v4 */
if(buffer[i]==4 && is_valid_sym_algo(buffer[i+1]) && is_valid_S2K(buffer[i+2]))
{
}
else
return 0;
}
else if(tag==OPENPGP_TAG_ONE_PASS_SIG)
{
if(buffer[i]==3 && is_valid_sym_algo(buffer[i+1]))
{
}
else
return 0;
}
else if(tag==OPENPGP_TAG_SYM_ENC_DATA)
{
unsigned int j;
int ok=0;
/* The symmetric cipher used may be specified in a Public-Key or
* Symmetric-Key Encrypted Session Key packet that precedes the
* Symmetrically Encrypted Data packet.
* PhotoRec assumes it must */
/*@
@ loop invariant 0 <= j <= nbr;
@ loop assigns j, ok;
@ loop variant nbr - j;
@*/
for(j=0; j<nbr; j++)
{
if(packet_tag[j]==OPENPGP_TAG_PUBKEY_ENC_SESSION_KEY ||
packet_tag[j]==OPENPGP_TAG_SYMKEY_ENC_SESSION_KEY)
ok=1;
}
if(ok==0)
return 0;
}
else if(tag==OPENPGP_TAG_MARKER)
{
/* Must be at the beginning of the packet */
if(nbr!=0)
return 0;
}
else if(tag==OPENPGP_TAG_SYM_ENC_INTEGRITY)
{
unsigned int j;
int ok=0;
#ifdef DEBUG_GPG
log_info("GPG :encrypted data packet:\n");
#endif
/* Version must be 1 */
if(buffer[i]!=1)
return 0;
/* The symmetric cipher used MUST be specified in a Public-Key or
* Symmetric-Key Encrypted Session Key packet that precedes the
* Symmetrically Encrypted Data packet. */
/*@
@ loop invariant 0 <= j <= nbr;
@ loop assigns j, ok;
@ loop variant nbr - j;
@*/
for(j=0; j<nbr; j++)
{
if(packet_tag[j]==OPENPGP_TAG_PUBKEY_ENC_SESSION_KEY ||
packet_tag[j]==OPENPGP_TAG_SYMKEY_ENC_SESSION_KEY)
ok=1;
}
if(ok==0)
return 0;
}
else if(tag==OPENPGP_TAG_PUB_KEY ||
tag==OPENPGP_TAG_PUB_SUBKEY ||
tag==OPENPGP_TAG_SEC_KEY||
tag==OPENPGP_TAG_SEC_SUBKEY)
{
if((buffer[i]==2 || buffer[i]==3) && is_valid_pubkey_algo(buffer[i+1+4+2]))
{ /* version 2 or 3 */
}
else if(buffer[i]==4 && is_valid_pubkey_algo(buffer[i+1+4]))
{ /* version 4 */
}
else
return 0;
}
}
if(partial_body_length==0)
nbr++;
i+=length;
}
if(nbr<2)
return 0;
if(memcmp(buffer, pgp_header, sizeof(pgp_header))==0)
{
reset_file_recovery(file_recovery_new);
file_recovery_new->file_check=&file_check_gpg;
file_recovery_new->extension=extension_pgp;
return 1;
}
/* encrypted_data.gpg */
if(((packet_tag[0]==OPENPGP_TAG_PUBKEY_ENC_SESSION_KEY ||
packet_tag[0]==OPENPGP_TAG_SYMKEY_ENC_SESSION_KEY) &&
(packet_tag[1]==OPENPGP_TAG_SYM_ENC_DATA ||
packet_tag[1]==OPENPGP_TAG_SYM_ENC_INTEGRITY)) ||
/* pubring.gpg */
(packet_tag[0]==OPENPGP_TAG_PUB_KEY &&
packet_tag[1]==OPENPGP_TAG_USER_ID &&
packet_tag[2]==OPENPGP_TAG_SIGNATURE &&
packet_tag[3]==OPENPGP_TAG_TRUST) ||
(packet_tag[0]==OPENPGP_TAG_PUB_KEY &&
packet_tag[1]==OPENPGP_TAG_USER_ID &&
packet_tag[2]==OPENPGP_TAG_SIGNATURE &&
packet_tag[3]==OPENPGP_TAG_PUB_SUBKEY) ||
/* secring.gpg */
(packet_tag[0]==OPENPGP_TAG_SEC_KEY &&
packet_tag[1]==OPENPGP_TAG_USER_ID &&
packet_tag[2]==OPENPGP_TAG_SIGNATURE &&
packet_tag[3]==OPENPGP_TAG_TRUST) ||
(packet_tag[0]==OPENPGP_TAG_SEC_KEY &&
packet_tag[1]==61 &&
packet_tag[2]==61 &&
packet_tag[3]==61))
{
reset_file_recovery(file_recovery_new);
file_recovery_new->file_check=&file_check_gpg;
file_recovery_new->extension=file_hint_gpg.extension;
return 1;
}
#ifdef DEBUG_GPG
log_info("tag don't match: nbr=%u - ", nbr);
for(i=0; i<nbr; i++)
log_info(" %u", packet_tag[i]);
log_info("\n");
#endif
return 0;
}
/*@
@ requires valid_register_header_check(file_stat);
@*/
static void register_header_check_gpg(file_stat_t *file_stat)
{
static const unsigned char gpg_header_pkey_enc[1]= {0x85};
static const unsigned char gpg_header_symkey_enc[1]= {0x8c};
static const unsigned char gpg_header_seckey[1]= {0x95};
static const unsigned char gpg_header_pkey[1]= {0x99};
register_header_check(0, gpg_header_seckey, sizeof(gpg_header_seckey), &header_check_gpg, file_stat);
#ifndef DISABLED_FOR_FRAMAC
register_header_check(0, gpg_header_symkey_enc, sizeof(gpg_header_symkey_enc), &header_check_gpg, file_stat);
register_header_check(0, gpg_header_pkey_enc, sizeof(gpg_header_pkey_enc), &header_check_gpg, file_stat);
register_header_check(0, pgp_header, sizeof(pgp_header), &header_check_gpg, file_stat);
register_header_check(0, gpg_header_pkey, sizeof(gpg_header_pkey), &header_check_gpg, file_stat);
#endif
}
#endif
#if defined(MAIN_gpg)
#define BLOCKSIZE 65536u
int main()
{
const char fn[] = "recup_dir.1/f0000000.gpg";
unsigned char buffer[BLOCKSIZE];
file_recovery_t file_recovery_new;
file_recovery_t file_recovery;
file_stat_t file_stats;
/*@ assert \valid(buffer + (0 .. (BLOCKSIZE - 1))); */
#if defined(__FRAMAC__)
Frama_C_make_unknown((char *)&buffer, BLOCKSIZE);
#endif
reset_file_recovery(&file_recovery);
/*@ assert file_recovery.file_stat == \null; */
file_recovery.blocksize=BLOCKSIZE;
file_recovery_new.blocksize=BLOCKSIZE;
file_recovery_new.data_check=NULL;
file_recovery_new.file_stat=NULL;
file_recovery_new.file_check=NULL;
file_recovery_new.file_rename=NULL;
file_recovery_new.calculated_file_size=0;
file_recovery_new.file_size=0;
file_recovery_new.location.start=0;
file_stats.file_hint=&file_hint_gpg;
file_stats.not_recovered=0;
file_stats.recovered=0;
register_header_check_gpg(&file_stats);
if(header_check_gpg(buffer, BLOCKSIZE, 0u, &file_recovery, &file_recovery_new)!=1)
return 0;
/*@ assert valid_read_string((char *)&fn); */
memcpy(file_recovery_new.filename, fn, sizeof(fn));
file_recovery_new.file_stat=&file_stats;
/*@ assert valid_read_string((char *)file_recovery_new.filename); */
/*@ assert file_recovery_new.extension == file_hint_gpg.extension || file_recovery_new.extension == extension_pgp; */
/*@ assert file_recovery_new.file_check == &file_check_gpg; */
/*@ assert file_recovery_new.file_stat->file_hint!=NULL; */
{
file_recovery_t file_recovery_new2;
file_recovery_new2.blocksize=BLOCKSIZE;
file_recovery_new2.file_stat=NULL;
file_recovery_new2.file_check=NULL;
file_recovery_new2.location.start=BLOCKSIZE;
file_recovery_new.handle=NULL; /* In theory should be not null */
#if defined(__FRAMAC__)
Frama_C_make_unknown((char *)buffer, BLOCKSIZE);
#endif
/*@ assert valid_read_string((char *)file_recovery_new.filename); */
header_check_gpg(buffer, BLOCKSIZE, 0, &file_recovery_new, &file_recovery_new2);
}
/*@ assert valid_read_string((char *)file_recovery_new.filename); */
file_recovery_new.handle=fopen(fn, "rb");
/*@ assert file_recovery_new.file_check == &file_check_gpg; */
if(file_recovery_new.handle!=NULL)
{
file_check_gpg(&file_recovery_new);
fclose(file_recovery_new.handle);
}
return 0;
}
#endif
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