/
metadata-verify.c
4447 lines (3561 loc) · 147 KB
/
metadata-verify.c
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/*
* metadata-verify.c: Metadata verfication support
*
* Author:
* Mono Project (http://www.mono-project.com)
*
* Copyright (C) 2005-2008 Novell, Inc. (http://www.novell.com)
* Licensed under the MIT license. See LICENSE file in the project root for full license information.
*/
#include <mono/metadata/object-internals.h>
#include <mono/metadata/verify.h>
#include <mono/metadata/verify-internals.h>
#include <mono/metadata/opcodes.h>
#include <mono/metadata/tabledefs.h>
#include <mono/metadata/reflection.h>
#include <mono/metadata/debug-helpers.h>
#include <mono/metadata/mono-endian.h>
#include <mono/metadata/metadata.h>
#include <mono/metadata/metadata-internals.h>
#include <mono/metadata/class-internals.h>
#include <mono/metadata/tokentype.h>
#include <mono/metadata/security-manager.h>
#include <mono/metadata/security-core-clr.h>
#include <mono/metadata/cil-coff.h>
#include <mono/metadata/attrdefs.h>
#include <mono/utils/strenc.h>
#include <mono/utils/mono-error-internals.h>
#include <mono/utils/bsearch.h>
#include <string.h>
//#include <signal.h>
#include <ctype.h>
#ifndef DISABLE_VERIFIER
/*
TODO add fail fast mode
TODO add PE32+ support
TODO verify the entry point RVA and content.
TODO load_section_table and load_data_directories must take PE32+ into account
TODO add section relocation support
TODO verify the relocation table, since we really don't use, no need so far.
TODO do full PECOFF resources verification
TODO verify in the CLI header entry point and resources
TODO implement null token typeref validation
TODO verify table wide invariants for typedef (sorting and uniqueness)
TODO implement proper authenticode data directory validation
TODO verify properties that require multiple tables to be valid
FIXME use subtraction based bounds checking to avoid overflows
FIXME get rid of metadata_streams and other fields from VerifyContext
*/
#ifdef MONO_VERIFIER_DEBUG
#define VERIFIER_DEBUG(code) do { code; } while (0)
#else
#define VERIFIER_DEBUG(code)
#endif
#define INVALID_OFFSET ((guint32)-1)
#define INVALID_ADDRESS 0xffffffff
enum {
STAGE_PE,
STAGE_CLI,
STAGE_TABLES
};
enum {
IMPORT_TABLE_IDX = 1,
RESOURCE_TABLE_IDX = 2,
CERTIFICATE_TABLE_IDX = 4,
RELOCATION_TABLE_IDX = 5,
IAT_IDX = 12,
CLI_HEADER_IDX = 14,
};
enum {
STRINGS_STREAM,
USER_STRINGS_STREAM,
BLOB_STREAM,
GUID_STREAM,
TILDE_STREAM
};
#define INVALID_TABLE (0xFF)
/*format: number of bits, number of tables, tables{n. tables} */
const static unsigned char coded_index_desc[] = {
#define TYPEDEF_OR_REF_DESC (0)
2, /*bits*/
3, /*tables*/
MONO_TABLE_TYPEDEF,
MONO_TABLE_TYPEREF,
MONO_TABLE_TYPESPEC,
#define HAS_CONSTANT_DESC (TYPEDEF_OR_REF_DESC + 5)
2, /*bits*/
3, /*tables*/
MONO_TABLE_FIELD,
MONO_TABLE_PARAM,
MONO_TABLE_PROPERTY,
#define HAS_CATTR_DESC (HAS_CONSTANT_DESC + 5)
5, /*bits*/
20, /*tables*/
MONO_TABLE_METHOD,
MONO_TABLE_FIELD,
MONO_TABLE_TYPEREF,
MONO_TABLE_TYPEDEF,
MONO_TABLE_PARAM,
MONO_TABLE_INTERFACEIMPL,
MONO_TABLE_MEMBERREF,
MONO_TABLE_MODULE,
MONO_TABLE_DECLSECURITY,
MONO_TABLE_PROPERTY,
MONO_TABLE_EVENT,
MONO_TABLE_STANDALONESIG,
MONO_TABLE_MODULEREF,
MONO_TABLE_TYPESPEC,
MONO_TABLE_ASSEMBLY,
MONO_TABLE_ASSEMBLYREF,
MONO_TABLE_FILE,
MONO_TABLE_EXPORTEDTYPE,
MONO_TABLE_MANIFESTRESOURCE,
MONO_TABLE_GENERICPARAM,
#define HAS_FIELD_MARSHAL_DESC (HAS_CATTR_DESC + 22)
1, /*bits*/
2, /*tables*/
MONO_TABLE_FIELD,
MONO_TABLE_PARAM,
#define HAS_DECL_SECURITY_DESC (HAS_FIELD_MARSHAL_DESC + 4)
2, /*bits*/
3, /*tables*/
MONO_TABLE_TYPEDEF,
MONO_TABLE_METHOD,
MONO_TABLE_ASSEMBLY,
#define MEMBERREF_PARENT_DESC (HAS_DECL_SECURITY_DESC + 5)
3, /*bits*/
5, /*tables*/
MONO_TABLE_TYPEDEF,
MONO_TABLE_TYPEREF,
MONO_TABLE_MODULEREF,
MONO_TABLE_METHOD,
MONO_TABLE_TYPESPEC,
#define HAS_SEMANTICS_DESC (MEMBERREF_PARENT_DESC + 7)
1, /*bits*/
2, /*tables*/
MONO_TABLE_EVENT,
MONO_TABLE_PROPERTY,
#define METHODDEF_OR_REF_DESC (HAS_SEMANTICS_DESC + 4)
1, /*bits*/
2, /*tables*/
MONO_TABLE_METHOD,
MONO_TABLE_MEMBERREF,
#define MEMBER_FORWARDED_DESC (METHODDEF_OR_REF_DESC + 4)
1, /*bits*/
2, /*tables*/
MONO_TABLE_FIELD,
MONO_TABLE_METHOD,
#define IMPLEMENTATION_DESC (MEMBER_FORWARDED_DESC + 4)
2, /*bits*/
3, /*tables*/
MONO_TABLE_FILE,
MONO_TABLE_ASSEMBLYREF,
MONO_TABLE_EXPORTEDTYPE,
#define CATTR_TYPE_DESC (IMPLEMENTATION_DESC + 5)
3, /*bits*/
5, /*tables*/
INVALID_TABLE,
INVALID_TABLE,
MONO_TABLE_METHOD,
MONO_TABLE_MEMBERREF,
INVALID_TABLE,
#define RES_SCOPE_DESC (CATTR_TYPE_DESC + 7)
2, /*bits*/
4, /*tables*/
MONO_TABLE_MODULE,
MONO_TABLE_MODULEREF,
MONO_TABLE_ASSEMBLYREF,
MONO_TABLE_TYPEREF,
#define TYPE_OR_METHODDEF_DESC (RES_SCOPE_DESC + 6)
1, /*bits*/
2, /*tables*/
MONO_TABLE_TYPEDEF,
MONO_TABLE_METHOD
};
typedef struct {
guint32 rva;
guint32 size;
guint32 translated_offset;
} DataDirectory;
typedef struct {
guint32 offset;
guint32 size;
} OffsetAndSize;
typedef struct {
guint32 baseRVA;
guint32 baseOffset;
guint32 size;
guint32 rellocationsRVA;
guint16 numberOfRelocations;
} SectionHeader;
typedef struct {
guint32 row_count;
guint32 row_size;
guint32 offset;
} TableInfo;
typedef struct {
const char *data;
guint32 size, token;
GSList *errors;
int valid;
MonoImage *image;
gboolean report_error;
gboolean report_warning;
int stage;
DataDirectory data_directories [16];
guint32 section_count;
SectionHeader *sections;
OffsetAndSize metadata_streams [5]; //offset from begin of the image
} VerifyContext;
#define ADD_VERIFY_INFO(__ctx, __msg, __status, __exception) \
do { \
MonoVerifyInfoExtended *vinfo = g_new (MonoVerifyInfoExtended, 1); \
vinfo->info.status = __status; \
vinfo->info.message = ( __msg); \
vinfo->exception_type = (__exception); \
(__ctx)->errors = g_slist_prepend ((__ctx)->errors, vinfo); \
} while (0)
#define ADD_WARNING(__ctx, __msg) \
do { \
if ((__ctx)->report_warning) { \
ADD_VERIFY_INFO(__ctx, __msg, MONO_VERIFY_WARNING, MONO_EXCEPTION_INVALID_PROGRAM); \
(__ctx)->valid = 0; \
return; \
} \
} while (0)
#define ADD_ERROR_NO_RETURN(__ctx, __msg) \
do { \
if ((__ctx)->report_error) \
ADD_VERIFY_INFO(__ctx, __msg, MONO_VERIFY_ERROR, MONO_EXCEPTION_INVALID_PROGRAM); \
(__ctx)->valid = 0; \
} while (0)
#define ADD_ERROR(__ctx, __msg) \
do { \
if ((__ctx)->report_error) \
ADD_VERIFY_INFO(__ctx, __msg, MONO_VERIFY_ERROR, MONO_EXCEPTION_INVALID_PROGRAM); \
(__ctx)->valid = 0; \
return; \
} while (0)
#define FAIL(__ctx, __msg) \
do { \
if ((__ctx)->report_error) \
ADD_VERIFY_INFO(__ctx, __msg, MONO_VERIFY_ERROR, MONO_EXCEPTION_INVALID_PROGRAM); \
(__ctx)->valid = 0; \
return FALSE; \
} while (0)
#define CHECK_STATE() do { if (!ctx.valid) goto cleanup; } while (0)
#define CHECK_ERROR() do { if (!ctx->valid) return; } while (0)
#define CHECK_ADD4_OVERFLOW_UN(a, b) ((guint32)(0xFFFFFFFFU) - (guint32)(b) < (guint32)(a))
#define CHECK_ADD8_OVERFLOW_UN(a, b) ((guint64)(0xFFFFFFFFFFFFFFFFUL) - (guint64)(b) < (guint64)(a))
#if SIZEOF_VOID_P == 4
#define CHECK_ADDP_OVERFLOW_UN(a,b) CHECK_ADD4_OVERFLOW_UN(a, b)
#else
#define CHECK_ADDP_OVERFLOW_UN(a,b) CHECK_ADD8_OVERFLOW_UN(a, b)
#endif
#define ADDP_IS_GREATER_OR_OVF(a, b, c) (((a) + (b) > (c)) || CHECK_ADDP_OVERFLOW_UN (a, b))
#define ADD_IS_GREATER_OR_OVF(a, b, c) (((a) + (b) > (c)) || CHECK_ADD4_OVERFLOW_UN (a, b))
static const char *
dword_align (const char *ptr)
{
#if SIZEOF_VOID_P == 8
return (const char *) (((guint64) (ptr + 3)) & ~3);
#else
return (const char *) (((guint32) (ptr + 3)) & ~3);
#endif
}
static void
add_from_mono_error (VerifyContext *ctx, MonoError *error)
{
if (mono_error_ok (error))
return;
ADD_ERROR (ctx, g_strdup (mono_error_get_message (error)));
mono_error_cleanup (error);
}
static guint32
pe_signature_offset (VerifyContext *ctx)
{
return read32 (ctx->data + 0x3c);
}
static guint32
pe_header_offset (VerifyContext *ctx)
{
return read32 (ctx->data + 0x3c) + 4;
}
static gboolean
bounds_check_virtual_address (VerifyContext *ctx, guint32 rva, guint32 size)
{
int i;
if (rva + size < rva) //overflow
return FALSE;
if (ctx->stage > STAGE_PE) {
MonoCLIImageInfo *iinfo = (MonoCLIImageInfo *)ctx->image->image_info;
const int top = iinfo->cli_section_count;
MonoSectionTable *tables = iinfo->cli_section_tables;
int i;
for (i = 0; i < top; i++) {
guint32 base = tables->st_virtual_address;
guint32 end = base + tables->st_raw_data_size;
if (rva >= base && rva + size <= end)
return TRUE;
/*if ((addr >= tables->st_virtual_address) &&
(addr < tables->st_virtual_address + tables->st_raw_data_size)){
return addr - tables->st_virtual_address + tables->st_raw_data_ptr;
}*/
tables++;
}
return FALSE;
}
if (!ctx->sections)
return FALSE;
for (i = 0; i < ctx->section_count; ++i) {
guint32 base = ctx->sections [i].baseRVA;
guint32 end = ctx->sections [i].baseRVA + ctx->sections [i].size;
if (rva >= base && rva + size <= end)
return TRUE;
}
return FALSE;
}
static gboolean
bounds_check_datadir (DataDirectory *dir, guint32 offset, guint32 size)
{
if (dir->translated_offset > offset)
return FALSE;
if (dir->size < size)
return FALSE;
return offset + size <= dir->translated_offset + dir->size;
}
static gboolean
bounds_check_offset (OffsetAndSize *off, guint32 offset, guint32 size)
{
if (off->offset > offset)
return FALSE;
if (off->size < size)
return FALSE;
return offset + size <= off->offset + off->size;
}
static guint32
translate_rva (VerifyContext *ctx, guint32 rva)
{
int i;
if (ctx->stage > STAGE_PE)
return mono_cli_rva_image_map (ctx->image, rva);
if (!ctx->sections)
return FALSE;
for (i = 0; i < ctx->section_count; ++i) {
guint32 base = ctx->sections [i].baseRVA;
guint32 end = ctx->sections [i].baseRVA + ctx->sections [i].size;
if (rva >= base && rva <= end) {
guint32 res = (rva - base) + ctx->sections [i].baseOffset;
/* double check */
return res >= ctx->size ? INVALID_OFFSET : res;
}
}
return INVALID_OFFSET;
}
static void
verify_msdos_header (VerifyContext *ctx)
{
guint32 lfanew;
if (ctx->size < 128)
ADD_ERROR (ctx, g_strdup ("Not enough space for the MS-DOS header"));
if (ctx->data [0] != 0x4d || ctx->data [1] != 0x5a)
ADD_ERROR (ctx, g_strdup ("Invalid MS-DOS watermark"));
lfanew = pe_signature_offset (ctx);
if (lfanew > ctx->size - 4)
ADD_ERROR (ctx, g_strdup ("MS-DOS lfanew offset points to outside of the file"));
}
static void
verify_pe_header (VerifyContext *ctx)
{
guint32 offset = pe_signature_offset (ctx);
const char *pe_header = ctx->data + offset;
if (pe_header [0] != 'P' || pe_header [1] != 'E' ||pe_header [2] != 0 ||pe_header [3] != 0)
ADD_ERROR (ctx, g_strdup ("Invalid PE header watermark"));
pe_header += 4;
offset += 4;
if (offset > ctx->size - 20)
ADD_ERROR (ctx, g_strdup ("File with truncated pe header"));
if (read16 (pe_header) != 0x14c)
ADD_ERROR (ctx, g_strdup ("Invalid PE header Machine value"));
}
static void
verify_pe_optional_header (VerifyContext *ctx)
{
guint32 offset = pe_header_offset (ctx);
guint32 header_size, file_alignment;
const char *pe_header = ctx->data + offset;
const char *pe_optional_header = pe_header + 20;
header_size = read16 (pe_header + 16);
offset += 20;
if (header_size < 2) /*must be at least 2 or we won't be able to read magic*/
ADD_ERROR (ctx, g_strdup ("Invalid PE optional header size"));
if (offset > ctx->size - header_size || header_size > ctx->size)
ADD_ERROR (ctx, g_strdup ("Invalid PE optional header size"));
if (read16 (pe_optional_header) == 0x10b) {
if (header_size != 224)
ADD_ERROR (ctx, g_strdup_printf ("Invalid optional header size %d", header_size));
/* LAMESPEC MS plays around this value and ignore it during validation
if (read32 (pe_optional_header + 28) != 0x400000)
ADD_ERROR (ctx, g_strdup_printf ("Invalid Image base %x", read32 (pe_optional_header + 28)));*/
if (read32 (pe_optional_header + 32) != 0x2000)
ADD_ERROR (ctx, g_strdup_printf ("Invalid Section Aligmnent %x", read32 (pe_optional_header + 32)));
file_alignment = read32 (pe_optional_header + 36);
if (file_alignment != 0x200 && file_alignment != 0x1000)
ADD_ERROR (ctx, g_strdup_printf ("Invalid file Aligmnent %x", file_alignment));
/* All the junk in the middle is irrelevant, specially for mono. */
if (read32 (pe_optional_header + 92) > 0x10)
ADD_ERROR (ctx, g_strdup_printf ("Too many data directories %x", read32 (pe_optional_header + 92)));
} else {
if (read16 (pe_optional_header) == 0x20B)
ADD_ERROR (ctx, g_strdup ("Metadata verifier doesn't handle PE32+"));
else
ADD_ERROR (ctx, g_strdup_printf ("Invalid optional header magic %d", read16 (pe_optional_header)));
}
}
static void
load_section_table (VerifyContext *ctx)
{
int i;
SectionHeader *sections;
guint32 offset = pe_header_offset (ctx);
const char *ptr = ctx->data + offset;
guint16 num_sections = ctx->section_count = read16 (ptr + 2);
offset += 244;/*FIXME, this constant is different under PE32+*/
ptr += 244;
if (num_sections * 40 > ctx->size - offset)
ADD_ERROR (ctx, g_strdup ("Invalid PE optional header size"));
sections = ctx->sections = g_new0 (SectionHeader, num_sections);
for (i = 0; i < num_sections; ++i) {
sections [i].size = read32 (ptr + 8);
sections [i].baseRVA = read32 (ptr + 12);
sections [i].baseOffset = read32 (ptr + 20);
sections [i].rellocationsRVA = read32 (ptr + 24);
sections [i].numberOfRelocations = read16 (ptr + 32);
ptr += 40;
}
ptr = ctx->data + offset; /*reset it to the beggining*/
for (i = 0; i < num_sections; ++i) {
guint32 raw_size, flags;
if (sections [i].baseOffset == 0)
ADD_ERROR (ctx, g_strdup ("Metadata verifier doesn't handle sections with intialized data only"));
if (sections [i].baseOffset >= ctx->size)
ADD_ERROR (ctx, g_strdup_printf ("Invalid PointerToRawData %x points beyond EOF", sections [i].baseOffset));
if (sections [i].size > ctx->size - sections [i].baseOffset)
ADD_ERROR (ctx, g_strdup ("Invalid VirtualSize points beyond EOF"));
raw_size = read32 (ptr + 16);
if (raw_size < sections [i].size)
ADD_ERROR (ctx, g_strdup ("Metadata verifier doesn't handle sections with SizeOfRawData < VirtualSize"));
if (raw_size > ctx->size - sections [i].baseOffset)
ADD_ERROR (ctx, g_strdup_printf ("Invalid SizeOfRawData %x points beyond EOF", raw_size));
if (sections [i].rellocationsRVA || sections [i].numberOfRelocations)
ADD_ERROR (ctx, g_strdup_printf ("Metadata verifier doesn't handle section relocation"));
flags = read32 (ptr + 36);
/*TODO 0xFE0000E0 is all flags from cil-coff.h OR'd. Make it a less magical number*/
if (flags == 0 || (flags & ~0xFE0000E0) != 0)
ADD_ERROR (ctx, g_strdup_printf ("Invalid section flags %x", flags));
ptr += 40;
}
}
static gboolean
is_valid_data_directory (int i)
{
/*LAMESPEC 4 == certificate 6 == debug, MS uses both*/
return i == 1 || i == 2 || i == 5 || i == 12 || i == 14 || i == 4 || i == 6;
}
static void
load_data_directories (VerifyContext *ctx)
{
guint32 offset = pe_header_offset (ctx) + 116; /*FIXME, this constant is different under PE32+*/
const char *ptr = ctx->data + offset;
int i;
for (i = 0; i < 16; ++i) {
guint32 rva = read32 (ptr);
guint32 size = read32 (ptr + 4);
/*LAMESPEC the authenticode data directory format is different. We don't support CAS, so lets ignore for now.*/
if (i == CERTIFICATE_TABLE_IDX) {
ptr += 8;
continue;
}
if ((rva != 0 || size != 0) && !is_valid_data_directory (i))
ADD_ERROR (ctx, g_strdup_printf ("Invalid data directory %d", i));
if (rva != 0 && !bounds_check_virtual_address (ctx, rva, size))
ADD_ERROR (ctx, g_strdup_printf ("Invalid data directory %d rva/size pair %x/%x", i, rva, size));
ctx->data_directories [i].rva = rva;
ctx->data_directories [i].size = size;
ctx->data_directories [i].translated_offset = translate_rva (ctx, rva);
ptr += 8;
}
}
#define SIZE_OF_MSCOREE (sizeof ("mscoree.dll"))
#define SIZE_OF_CORMAIN (sizeof ("_CorExeMain"))
static void
verify_hint_name_table (VerifyContext *ctx, guint32 import_rva, const char *table_name)
{
const char *ptr;
guint32 hint_table_rva;
import_rva = translate_rva (ctx, import_rva);
g_assert (import_rva != INVALID_OFFSET);
hint_table_rva = read32 (ctx->data + import_rva);
if (!bounds_check_virtual_address (ctx, hint_table_rva, SIZE_OF_CORMAIN + 2))
ADD_ERROR (ctx, g_strdup_printf ("Invalid Hint/Name rva %d for %s", hint_table_rva, table_name));
hint_table_rva = translate_rva (ctx, hint_table_rva);
g_assert (hint_table_rva != INVALID_OFFSET);
ptr = ctx->data + hint_table_rva + 2;
if (memcmp ("_CorExeMain", ptr, SIZE_OF_CORMAIN) && memcmp ("_CorDllMain", ptr, SIZE_OF_CORMAIN)) {
char name[SIZE_OF_CORMAIN];
memcpy (name, ptr, SIZE_OF_CORMAIN);
name [SIZE_OF_CORMAIN - 1] = 0;
ADD_ERROR (ctx, g_strdup_printf ("Invalid Hint / Name: '%s'", name));
}
}
static void
verify_import_table (VerifyContext *ctx)
{
DataDirectory it = ctx->data_directories [IMPORT_TABLE_IDX];
guint32 offset = it.translated_offset;
const char *ptr = ctx->data + offset;
guint32 name_rva, ilt_rva, iat_rva;
g_assert (offset != INVALID_OFFSET);
if (it.size < 40)
ADD_ERROR (ctx, g_strdup_printf ("Import table size %d is smaller than 40", it.size));
ilt_rva = read32 (ptr);
if (ilt_rva && !bounds_check_virtual_address (ctx, ilt_rva, 8))
ADD_ERROR (ctx, g_strdup_printf ("Invalid Import Lookup Table rva %x", ilt_rva));
name_rva = read32 (ptr + 12);
if (name_rva && !bounds_check_virtual_address (ctx, name_rva, SIZE_OF_MSCOREE))
ADD_ERROR (ctx, g_strdup_printf ("Invalid Import Table Name rva %x", name_rva));
iat_rva = read32 (ptr + 16);
if (iat_rva) {
if (!bounds_check_virtual_address (ctx, iat_rva, 8))
ADD_ERROR (ctx, g_strdup_printf ("Invalid Import Address Table rva %x", iat_rva));
if (iat_rva != ctx->data_directories [IAT_IDX].rva)
ADD_ERROR (ctx, g_strdup_printf ("Import Address Table rva %x different from data directory entry %x", read32 (ptr + 16), ctx->data_directories [IAT_IDX].rva));
}
if (name_rva) {
name_rva = translate_rva (ctx, name_rva);
g_assert (name_rva != INVALID_OFFSET);
ptr = ctx->data + name_rva;
if (memcmp ("mscoree.dll", ptr, SIZE_OF_MSCOREE)) {
char name[SIZE_OF_MSCOREE];
memcpy (name, ptr, SIZE_OF_MSCOREE);
name [SIZE_OF_MSCOREE - 1] = 0;
ADD_ERROR (ctx, g_strdup_printf ("Invalid Import Table Name: '%s'", name));
}
}
if (ilt_rva) {
verify_hint_name_table (ctx, ilt_rva, "Import Lookup Table");
CHECK_ERROR ();
}
if (iat_rva)
verify_hint_name_table (ctx, iat_rva, "Import Address Table");
}
static void
verify_resources_table (VerifyContext *ctx)
{
DataDirectory it = ctx->data_directories [RESOURCE_TABLE_IDX];
guint32 offset;
guint16 named_entries, id_entries;
const char *ptr;
if (it.rva == 0)
return;
if (it.size < 16)
ADD_ERROR (ctx, g_strdup_printf ("Resource section is too small, must be at least 16 bytes long but it's %d long", it.size));
offset = it.translated_offset;
ptr = ctx->data + offset;
g_assert (offset != INVALID_OFFSET);
named_entries = read16 (ptr + 12);
id_entries = read16 (ptr + 14);
if ((named_entries + id_entries) * 8 + 16 > it.size)
ADD_ERROR (ctx, g_strdup_printf ("Resource section is too small, the number of entries (%d) doesn't fit on it's size %d", named_entries + id_entries, it.size));
/* XXX at least one unmanaged resource is added due to a call to AssemblyBuilder::DefineVersionInfoResource ()
if (named_entries || id_entries)
ADD_ERROR (ctx, g_strdup_printf ("The metadata verifier doesn't support full verification of PECOFF resources"));
*/
}
/*----------nothing from here on can use data_directory---*/
static DataDirectory
get_data_dir (VerifyContext *ctx, int idx)
{
MonoCLIImageInfo *iinfo = (MonoCLIImageInfo *)ctx->image->image_info;
MonoPEDirEntry *entry= &iinfo->cli_header.datadir.pe_export_table;
DataDirectory res;
entry += idx;
res.rva = entry->rva;
res.size = entry->size;
res.translated_offset = translate_rva (ctx, res.rva);
return res;
}
static void
verify_cli_header (VerifyContext *ctx)
{
DataDirectory it = get_data_dir (ctx, CLI_HEADER_IDX);
guint32 offset;
const char *ptr;
int i;
if (it.rva == 0)
ADD_ERROR (ctx, g_strdup_printf ("CLI header missing"));
if (it.size != 72)
ADD_ERROR (ctx, g_strdup_printf ("Invalid cli header size in data directory %d must be 72", it.size));
offset = it.translated_offset;
ptr = ctx->data + offset;
g_assert (offset != INVALID_OFFSET);
if (read16 (ptr) != 72)
ADD_ERROR (ctx, g_strdup_printf ("Invalid cli header size %d must be 72", read16 (ptr)));
if (!bounds_check_virtual_address (ctx, read32 (ptr + 8), read32 (ptr + 12)))
ADD_ERROR (ctx, g_strdup_printf ("Invalid medatata section rva/size pair %x/%x", read32 (ptr + 8), read32 (ptr + 12)));
if (!read32 (ptr + 8) || !read32 (ptr + 12))
ADD_ERROR (ctx, g_strdup_printf ("Missing medatata section in the CLI header"));
if ((read32 (ptr + 16) & ~0x0003000B) != 0)
ADD_ERROR (ctx, g_strdup_printf ("Invalid CLI header flags"));
ptr += 24;
for (i = 0; i < 6; ++i) {
guint32 rva = read32 (ptr);
guint32 size = read32 (ptr + 4);
if (rva != 0 && !bounds_check_virtual_address (ctx, rva, size))
ADD_ERROR (ctx, g_strdup_printf ("Invalid cli section %i rva/size pair %x/%x", i, rva, size));
ptr += 8;
if (rva && i > 1)
ADD_ERROR (ctx, g_strdup_printf ("Metadata verifier doesn't support cli header section %d", i));
}
}
static guint32
pad4 (guint32 offset)
{
if (offset & 0x3) //pad to the next 4 byte boundary
offset = (offset & ~0x3) + 4;
return offset;
}
static void
verify_metadata_header (VerifyContext *ctx)
{
int i;
DataDirectory it = get_data_dir (ctx, CLI_HEADER_IDX);
guint32 offset, section_count;
const char *ptr;
offset = it.translated_offset;
ptr = ctx->data + offset;
g_assert (offset != INVALID_OFFSET);
//build a directory entry for the metadata root
ptr += 8;
it.rva = read32 (ptr);
ptr += 4;
it.size = read32 (ptr);
it.translated_offset = offset = translate_rva (ctx, it.rva);
ptr = ctx->data + offset;
g_assert (offset != INVALID_OFFSET);
if (it.size < 20)
ADD_ERROR (ctx, g_strdup_printf ("Metadata root section is too small %d (at least 20 bytes required for initial decoding)", it.size));
if (read32 (ptr) != 0x424A5342)
ADD_ERROR (ctx, g_strdup_printf ("Invalid metadata signature, expected 0x424A5342 but got %08x", read32 (ptr)));
offset = pad4 (offset + 16 + read32 (ptr + 12));
if (!bounds_check_datadir (&it, offset, 4))
ADD_ERROR (ctx, g_strdup_printf ("Metadata root section is too small %d (at least %d bytes required for flags decoding)", it.size, offset + 4 - it.translated_offset));
ptr = ctx->data + offset; //move to streams header
section_count = read16 (ptr + 2);
if (section_count < 2)
ADD_ERROR (ctx, g_strdup_printf ("Metadata root section must have at least 2 streams (#~ and #GUID)"));
ptr += 4;
offset += 4;
for (i = 0; i < section_count; ++i) {
guint32 stream_off, stream_size;
int string_size, stream_idx;
if (!bounds_check_datadir (&it, offset, 8))
ADD_ERROR (ctx, g_strdup_printf ("Metadata root section is too small for initial decode of stream header %d, missing %d bytes", i, offset + 9 - it.translated_offset));
stream_off = it.translated_offset + read32 (ptr);
stream_size = read32 (ptr + 4);
if (!bounds_check_datadir (&it, stream_off, stream_size))
ADD_ERROR (ctx, g_strdup_printf ("Invalid stream header %d offset/size pair %x/%x", 0, stream_off, stream_size));
ptr += 8;
offset += 8;
for (string_size = 0; string_size < 32; ++string_size) {
if (!bounds_check_datadir (&it, offset++, 1))
ADD_ERROR (ctx, g_strdup_printf ("Metadata root section is too small to decode stream header %d name", i));
if (!ptr [string_size])
break;
}
if (ptr [string_size])
ADD_ERROR (ctx, g_strdup_printf ("Metadata stream header %d name larger than 32 bytes", i));
if (!strncmp ("#Strings", ptr, 9))
stream_idx = STRINGS_STREAM;
else if (!strncmp ("#US", ptr, 4))
stream_idx = USER_STRINGS_STREAM;
else if (!strncmp ("#Blob", ptr, 6))
stream_idx = BLOB_STREAM;
else if (!strncmp ("#GUID", ptr, 6))
stream_idx = GUID_STREAM;
else if (!strncmp ("#~", ptr, 3))
stream_idx = TILDE_STREAM;
else {
ADD_WARNING (ctx, g_strdup_printf ("Metadata stream header %d invalid name %s", i, ptr));
offset = pad4 (offset);
ptr = ctx->data + offset;
continue;
}
if (ctx->metadata_streams [stream_idx].offset != 0)
ADD_ERROR (ctx, g_strdup_printf ("Duplicated metadata stream header %s", ptr));
ctx->metadata_streams [stream_idx].offset = stream_off;
ctx->metadata_streams [stream_idx].size = stream_size;
offset = pad4 (offset);
ptr = ctx->data + offset;
}
if (!ctx->metadata_streams [TILDE_STREAM].size)
ADD_ERROR (ctx, g_strdup_printf ("Metadata #~ stream missing"));
if (!ctx->metadata_streams [GUID_STREAM].size)
ADD_ERROR (ctx, g_strdup_printf ("Metadata guid stream missing"));
}
static void
verify_tables_schema (VerifyContext *ctx)
{
OffsetAndSize tables_area = ctx->metadata_streams [TILDE_STREAM];
unsigned offset = tables_area.offset;
const char *ptr = ctx->data + offset;
guint64 valid_tables;
guint32 count;
int i;
if (tables_area.size < 24)
ADD_ERROR (ctx, g_strdup_printf ("Table schemata size (%d) too small to for initial decoding (requires 24 bytes)", tables_area.size));
if (ptr [4] != 2 && ptr [4] != 1)
ADD_ERROR (ctx, g_strdup_printf ("Invalid table schemata major version %d, expected 2", ptr [4]));
if (ptr [5] != 0)
ADD_ERROR (ctx, g_strdup_printf ("Invalid table schemata minor version %d, expected 0", ptr [5]));
if ((ptr [6] & ~0x7) != 0)
ADD_ERROR (ctx, g_strdup_printf ("Invalid table schemata heap sizes 0x%02x, only bits 0, 1 and 2 can be set", ((unsigned char *) ptr) [6]));
valid_tables = read64 (ptr + 8);
count = 0;
for (i = 0; i < 64; ++i) {
if (!(valid_tables & ((guint64)1 << i)))
continue;
/*MS Extensions: 0x3 0x5 0x7 0x13 0x16
Unused: 0x1E 0x1F 0x2D-0x3F
We don't care about the MS extensions.*/
if (i == 0x3 || i == 0x5 || i == 0x7 || i == 0x13 || i == 0x16)
ADD_ERROR (ctx, g_strdup_printf ("The metadata verifier doesn't support MS specific table %x", i));
if (i == 0x1E || i == 0x1F || i >= 0x2D)
ADD_ERROR (ctx, g_strdup_printf ("Invalid table %x", i));
++count;
}
if (tables_area.size < 24 + count * 4)
ADD_ERROR (ctx, g_strdup_printf ("Table schemata size (%d) too small to for decoding row counts (requires %d bytes)", tables_area.size, 24 + count * 4));
ptr += 24;
for (i = 0; i < 64; ++i) {
if (valid_tables & ((guint64)1 << i)) {
guint32 row_count = read32 (ptr);
if (row_count > (1 << 24) - 1)
ADD_ERROR (ctx, g_strdup_printf ("Invalid Table %d row count: %d. Mono only supports 16777215 rows", i, row_count));
ptr += 4;
}
}
}
/*----------nothing from here on can use data_directory or metadata_streams ---*/
static guint32
get_col_offset (VerifyContext *ctx, int table, int column)
{
guint32 bitfield = ctx->image->tables [table].size_bitfield;
guint32 offset = 0;
while (column-- > 0)
offset += mono_metadata_table_size (bitfield, column);
return offset;
}
static guint32
get_col_size (VerifyContext *ctx, int table, int column)
{
return mono_metadata_table_size (ctx->image->tables [table].size_bitfield, column);
}
static OffsetAndSize
get_metadata_stream (VerifyContext *ctx, MonoStreamHeader *header)
{
OffsetAndSize res;
res.offset = header->data - ctx->data;
res.size = header->size;
return res;
}
static gboolean
is_valid_string_full_with_image (MonoImage *image, guint32 offset, gboolean allow_empty)
{
guint32 heap_offset = (char*)image->heap_strings.data - image->raw_data;
guint32 heap_size = image->heap_strings.size;
glong length;
const char *data = image->raw_data + heap_offset;
if (offset >= heap_size)
return FALSE;
if (CHECK_ADDP_OVERFLOW_UN (data, offset))
return FALSE;
if (!mono_utf8_validate_and_len_with_bounds (data + offset, heap_size - offset, &length, NULL))
return FALSE;
return allow_empty || length > 0;
}
static gboolean
is_valid_string_full (VerifyContext *ctx, guint32 offset, gboolean allow_empty)
{
return is_valid_string_full_with_image (ctx->image, offset, allow_empty);
}
static gboolean
is_valid_string (VerifyContext *ctx, guint32 offset)
{
return is_valid_string_full (ctx, offset, TRUE);
}
static gboolean
is_valid_non_empty_string (VerifyContext *ctx, guint32 offset)
{
return is_valid_string_full (ctx, offset, FALSE);
}
static gboolean
is_valid_guid (VerifyContext *ctx, guint32 offset)
{
OffsetAndSize guids = get_metadata_stream (ctx, &ctx->image->heap_guid);
return guids.size >= 8 && guids.size - 8 >= offset;
}
static guint32
get_coded_index_token (int token_kind, guint32 coded_token)
{
guint32 bits = coded_index_desc [token_kind];
return coded_token >> bits;
}
static guint32
get_coded_index_table (int kind, guint32 coded_token)
{
guint32 idx, bits = coded_index_desc [kind];
kind += 2;
idx = coded_token & ((1 << bits) - 1);
return coded_index_desc [kind + idx];
}