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msi.c
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msi.c
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/*
* MSI file support library
*
* Copyright (C) 2021-2023 Michał Trojnara <Michal.Trojnara@stunnel.org>
* Author: Małgorzata Olszówka <Malgorzata.Olszowka@stunnel.org>
*
* Reference specifications:
* http://en.wikipedia.org/wiki/Compound_File_Binary_Format
* https://msdn.microsoft.com/en-us/library/dd942138.aspx
* https://github.com/microsoft/compoundfilereader
*/
#include "osslsigncode.h"
#include "helpers.h"
#define MAXREGSECT 0xfffffffa /* maximum regular sector number */
#define DIFSECT 0xfffffffc /* specifies a DIFAT sector in the FAT */
#define FATSECT 0xfffffffd /* specifies a FAT sector in the FAT */
#define ENDOFCHAIN 0xfffffffe /* end of a linked chain of sectors */
#define NOSTREAM 0xffffffff /* terminator or empty pointer */
#define FREESECT 0xffffffff /* empty unallocated free sectors */
#define DIR_UNKNOWN 0
#define DIR_STORAGE 1
#define DIR_STREAM 2
#define DIR_ROOT 5
#define RED_COLOR 0
#define BLACK_COLOR 1
#define DIFAT_IN_HEADER 109
#define MINI_STREAM_CUTOFF_SIZE 0x00001000 /* 4096 bytes */
#define HEADER_SIZE 0x200 /* 512 bytes, independent of sector size */
#define MAX_SECTOR_SIZE 0x1000 /* 4096 bytes */
#define HEADER_SIGNATURE 0x00 /* 0xD0, 0xCF, 0x11, 0xE0, 0xA1, 0xB1, 0x1A, 0xE1 */
#define HEADER_CLSID 0x08 /* reserved and unused */
#define HEADER_MINOR_VER 0x18 /* SHOULD be set to 0x003E */
#define HEADER_MAJOR_VER 0x1a /* MUST be set to either 0x0003 (version 3) or 0x0004 (version 4) */
#define HEADER_BYTE_ORDER 0x1c /* 0xfe 0xff == Intel Little Endian */
#define HEADER_SECTOR_SHIFT 0x1e /* MUST be set to 0x0009, or 0x000c */
#define HEADER_MINI_SECTOR_SHIFT 0x20 /* MUST be set to 0x0006 */
#define RESERVED 0x22 /* reserved and unused */
#define HEADER_DIR_SECTORS_NUM 0x28
#define HEADER_FAT_SECTORS_NUM 0x2c
#define HEADER_DIR_SECTOR_LOC 0x30
#define HEADER_TRANSACTION 0x34
#define HEADER_MINI_STREAM_CUTOFF 0x38 /* 4096 bytes */
#define HEADER_MINI_FAT_SECTOR_LOC 0x3c
#define HEADER_MINI_FAT_SECTORS_NUM 0x40
#define HEADER_DIFAT_SECTOR_LOC 0x44
#define HEADER_DIFAT_SECTORS_NUM 0x48
#define HEADER_DIFAT 0x4c
#define DIRENT_SIZE 0x80 /* 128 bytes */
#define DIRENT_MAX_NAME_SIZE 0x40 /* 64 bytes */
#define DIRENT_NAME 0x00
#define DIRENT_NAME_LEN 0x40 /* length in bytes incl 0 terminator */
#define DIRENT_TYPE 0x42
#define DIRENT_COLOUR 0x43
#define DIRENT_LEFT_SIBLING_ID 0x44
#define DIRENT_RIGHT_SIBLING_ID 0x48
#define DIRENT_CHILD_ID 0x4c
#define DIRENT_CLSID 0x50
#define DIRENT_STATE_BITS 0x60
#define DIRENT_CREATE_TIME 0x64
#define DIRENT_MODIFY_TIME 0x6c
#define DIRENT_START_SECTOR_LOC 0x74
#define DIRENT_FILE_SIZE 0x78
static const u_char msi_magic[] = {
0xd0, 0xcf, 0x11, 0xe0, 0xa1, 0xb1, 0x1a, 0xe1
};
static const u_char digital_signature[] = {
0x05, 0x00, 0x44, 0x00, 0x69, 0x00, 0x67, 0x00,
0x69, 0x00, 0x74, 0x00, 0x61, 0x00, 0x6C, 0x00,
0x53, 0x00, 0x69, 0x00, 0x67, 0x00, 0x6E, 0x00,
0x61, 0x00, 0x74, 0x00, 0x75, 0x00, 0x72, 0x00,
0x65, 0x00, 0x00, 0x00
};
static const u_char digital_signature_ex[] = {
0x05, 0x00, 0x4D, 0x00, 0x73, 0x00, 0x69, 0x00,
0x44, 0x00, 0x69, 0x00, 0x67, 0x00, 0x69, 0x00,
0x74, 0x00, 0x61, 0x00, 0x6C, 0x00, 0x53, 0x00,
0x69, 0x00, 0x67, 0x00, 0x6E, 0x00, 0x61, 0x00,
0x74, 0x00, 0x75, 0x00, 0x72, 0x00, 0x65, 0x00,
0x45, 0x00, 0x78, 0x00, 0x00, 0x00
};
static const u_char msi_root_entry[] = {
0x52, 0x00, 0x6F, 0x00, 0x6F, 0x00, 0x74, 0x00,
0x20, 0x00, 0x45, 0x00, 0x6E, 0x00, 0x74, 0x00,
0x72, 0x00, 0x79, 0x00, 0x00, 0x00
};
static const u_char msi_zeroes[] = {
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};
typedef struct {
u_char signature[8]; /* 0xd0, 0xcf, 0x11, 0xe0, 0xa1, 0xb1, 0x1a, 0xe1 */
u_char unused_clsid[16]; /* reserved and unused */
uint16_t minorVersion;
uint16_t majorVersion;
uint16_t byteOrder;
uint16_t sectorShift; /* power of 2 */
uint16_t miniSectorShift; /* power of 2 */
u_char reserved[6]; /* reserved and unused */
uint32_t numDirectorySector;
uint32_t numFATSector;
uint32_t firstDirectorySectorLocation;
uint32_t transactionSignatureNumber; /* reserved */
uint32_t miniStreamCutoffSize;
uint32_t firstMiniFATSectorLocation;
uint32_t numMiniFATSector;
uint32_t firstDIFATSectorLocation;
uint32_t numDIFATSector;
uint32_t headerDIFAT[DIFAT_IN_HEADER];
} MSI_FILE_HDR;
typedef struct {
u_char name[DIRENT_MAX_NAME_SIZE];
uint16_t nameLen;
uint8_t type;
uint8_t colorFlag;
uint32_t leftSiblingID;
uint32_t rightSiblingID;
uint32_t childID;
u_char clsid[16];
u_char stateBits[4];
u_char creationTime[8];
u_char modifiedTime[8];
uint32_t startSectorLocation;
u_char size[8];
} MSI_ENTRY;
typedef struct msi_dirent_struct {
u_char name[DIRENT_MAX_NAME_SIZE];
uint16_t nameLen;
uint8_t type;
MSI_ENTRY *entry;
STACK_OF(MSI_DIRENT) *children;
struct msi_dirent_struct *next; /* for cycle detection */
} MSI_DIRENT;
DEFINE_STACK_OF(MSI_DIRENT)
typedef struct {
const u_char *m_buffer;
uint32_t m_bufferLen;
MSI_FILE_HDR *m_hdr;
uint32_t m_sectorSize;
uint32_t m_minisectorSize;
uint32_t m_miniStreamStartSector;
} MSI_FILE;
typedef struct {
char *header;
char *ministream;
char *minifat;
char *fat;
char *difat;
uint32_t dirtreeLen;
uint32_t miniStreamLen;
uint32_t minifatLen;
uint32_t fatLen;
uint32_t difatLen;
uint32_t ministreamsMemallocCount;
uint32_t minifatMemallocCount;
uint32_t fatMemallocCount;
uint32_t difatMemallocCount;
uint32_t dirtreeSectorsCount;
uint32_t minifatSectorsCount;
uint32_t fatSectorsCount;
uint32_t miniSectorNum;
uint32_t sectorNum;
uint32_t sectorSize;
} MSI_OUT;
struct msi_ctx_st {
MSI_FILE *msi;
MSI_DIRENT *dirent;
u_char *p_msiex; /* MsiDigitalSignatureEx stream data */
uint32_t len_msiex; /* MsiDigitalSignatureEx stream data length */
uint32_t fileend;
};
/* FILE_FORMAT method prototypes */
static FILE_FORMAT_CTX *msi_ctx_new(GLOBAL_OPTIONS *options, BIO *hash, BIO *outdata);
static ASN1_OBJECT *msi_spc_sip_info_get(u_char **p, int *plen, FILE_FORMAT_CTX *ctx);
static PKCS7 *msi_pkcs7_contents_get(FILE_FORMAT_CTX *ctx, BIO *hash, const EVP_MD *md);
static int msi_hash_length_get(FILE_FORMAT_CTX *ctx);
static u_char *msi_digest_calc(FILE_FORMAT_CTX *ctx, const EVP_MD *md);
static int msi_verify_digests(FILE_FORMAT_CTX *ctx, PKCS7 *p7);
static PKCS7 *msi_pkcs7_extract(FILE_FORMAT_CTX *ctx);
static PKCS7 *msi_pkcs7_extract_to_nest(FILE_FORMAT_CTX *ctx);
static int msi_remove_pkcs7(FILE_FORMAT_CTX *ctx, BIO *hash, BIO *outdata);
static int msi_process_data(FILE_FORMAT_CTX *ctx, BIO *hash, BIO *outdata);
static PKCS7 *msi_pkcs7_signature_new(FILE_FORMAT_CTX *ctx, BIO *hash);
static int msi_append_pkcs7(FILE_FORMAT_CTX *ctx, BIO *outdata, PKCS7 *p7);
static void msi_bio_free(BIO *hash, BIO *outdata);
static void msi_ctx_cleanup(FILE_FORMAT_CTX *ctx);
static int msi_is_detaching_supported(void);
FILE_FORMAT file_format_msi = {
.ctx_new = msi_ctx_new,
.data_blob_get = msi_spc_sip_info_get,
.pkcs7_contents_get = msi_pkcs7_contents_get,
.hash_length_get = msi_hash_length_get,
.digest_calc = msi_digest_calc,
.verify_digests = msi_verify_digests,
.pkcs7_extract = msi_pkcs7_extract,
.pkcs7_extract_to_nest = msi_pkcs7_extract_to_nest,
.remove_pkcs7 = msi_remove_pkcs7,
.process_data = msi_process_data,
.pkcs7_signature_new = msi_pkcs7_signature_new,
.append_pkcs7 = msi_append_pkcs7,
.bio_free = msi_bio_free,
.ctx_cleanup = msi_ctx_cleanup,
.is_detaching_supported = msi_is_detaching_supported
};
/* Prototypes */
static MSI_CTX *msi_ctx_get(char *indata, uint32_t filesize);
static PKCS7 *msi_pkcs7_get_digital_signature(FILE_FORMAT_CTX *ctx, MSI_ENTRY *ds);
static int recurse_entry(MSI_FILE *msi, uint32_t entryID, MSI_DIRENT *parent);
static int msi_file_write(MSI_FILE *msi, MSI_DIRENT *dirent, u_char *p_msi, uint32_t len_msi,
u_char *p_msiex, uint32_t len_msiex, BIO *outdata);
static MSI_ENTRY *msi_signatures_get(MSI_DIRENT *dirent, MSI_ENTRY **dse);
static int msi_file_read(MSI_FILE *msi, MSI_ENTRY *entry, uint32_t offset, char *buffer, uint32_t len);
static int msi_dirent_delete(MSI_DIRENT *dirent, const u_char *name, uint16_t nameLen);
static BIO *msi_digest_calc_bio(FILE_FORMAT_CTX *ctx, BIO *hash);
static int msi_calc_MsiDigitalSignatureEx(FILE_FORMAT_CTX *ctx, BIO *hash);
static int msi_check_MsiDigitalSignatureEx(FILE_FORMAT_CTX *ctx, MSI_ENTRY *dse, PKCS7 *p7);
static int msi_hash_dir(MSI_FILE *msi, MSI_DIRENT *dirent, BIO *hash, int is_root);
static MSI_ENTRY *msi_root_entry_get(MSI_FILE *msi);
static void msi_file_free(MSI_FILE *msi);
static MSI_FILE *msi_file_new(char *buffer, uint32_t len);
static int msi_dirent_new(MSI_FILE *msi, MSI_ENTRY *entry, MSI_DIRENT *parent, MSI_DIRENT **ret);
static void msi_dirent_free(MSI_DIRENT *dirent);
static int msi_prehash_dir(MSI_DIRENT *dirent, BIO *hash, int is_root);
static int msi_check_file(FILE_FORMAT_CTX *ctx);
/*
* FILE_FORMAT method definitions
*/
/*
* Allocate and return a MSI file format context.
* [in, out] options: structure holds the input data
* [out] hash: message digest BIO
* [in] outdata: outdata file BIO (unused)
* [returns] pointer to MSI file format context
*/
static FILE_FORMAT_CTX *msi_ctx_new(GLOBAL_OPTIONS *options, BIO *hash, BIO *outdata)
{
FILE_FORMAT_CTX *ctx;
MSI_CTX *msi_ctx;
uint32_t filesize;
/* squash the unused parameter warning */
(void)outdata;
filesize = get_file_size(options->infile);
if (filesize == 0)
return NULL; /* FAILED */
options->indata = map_file(options->infile, filesize);
if (!options->indata) {
return NULL; /* FAILED */
}
if (memcmp(options->indata, msi_magic, sizeof msi_magic)) {
unmap_file(options->indata, filesize);
return NULL; /* FAILED */
}
msi_ctx = msi_ctx_get(options->indata, filesize);
if (!msi_ctx) {
unmap_file(options->indata, filesize);
return NULL; /* FAILED */
}
ctx = OPENSSL_malloc(sizeof(FILE_FORMAT_CTX));
ctx->format = &file_format_msi;
ctx->options = options;
ctx->msi_ctx = msi_ctx;
if (hash)
BIO_push(hash, BIO_new(BIO_s_null()));
if (options->pagehash == 1)
printf("Warning: -ph option is only valid for PE files\n");
if (options->jp >= 0)
printf("Warning: -jp option is only valid for CAB files\n");
return ctx;
}
/*
* Allocate and return SpcSipInfo object.
* Subject Interface Package (SIP) is an internal Microsoft API for
* transforming arbitrary files into a digestible stream.
* These ClassIDs are found in the indirect data section and identify
* the type of processor needed to validate the signature.
* [out] p: SpcSipInfo data
* [out] plen: SpcSipInfo data length
* [in] ctx: structure holds input and output data (unused)
* [returns] pointer to ASN1_OBJECT structure corresponding to SPC_SIPINFO_OBJID
*/
static ASN1_OBJECT *msi_spc_sip_info_get(u_char **p, int *plen, FILE_FORMAT_CTX *ctx)
{
const u_char SpcUUIDSipInfoMsi[] = {
0xf1, 0x10, 0x0c, 0x00, 0x00, 0x00, 0x00, 0x00,
0xc0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x46
};
ASN1_OBJECT *dtype;
SpcSipInfo *si = SpcSipInfo_new();
/* squash the unused parameter warning */
(void)ctx;
ASN1_INTEGER_set(si->a, 1);
ASN1_INTEGER_set(si->b, 0);
ASN1_INTEGER_set(si->c, 0);
ASN1_INTEGER_set(si->d, 0);
ASN1_INTEGER_set(si->e, 0);
ASN1_INTEGER_set(si->f, 0);
ASN1_OCTET_STRING_set(si->string, SpcUUIDSipInfoMsi, sizeof SpcUUIDSipInfoMsi);
*plen = i2d_SpcSipInfo(si, NULL);
*p = OPENSSL_malloc((size_t)*plen);
i2d_SpcSipInfo(si, p);
*p -= *plen;
dtype = OBJ_txt2obj(SPC_SIPINFO_OBJID, 1);
SpcSipInfo_free(si);
return dtype; /* OK */
}
/*
* Allocate and return a data content to be signed.
* [in] ctx: structure holds input and output data
* [in] hash: message digest BIO
* [in] md: message digest algorithm
* [returns] data content
*/
static PKCS7 *msi_pkcs7_contents_get(FILE_FORMAT_CTX *ctx, BIO *hash, const EVP_MD *md)
{
ASN1_OCTET_STRING *content;
/* squash the unused parameter warning, use initialized message digest BIO */
(void)md;
if (ctx->options->add_msi_dse && !msi_calc_MsiDigitalSignatureEx(ctx, hash)) {
printf("Unable to calc MsiDigitalSignatureEx\n");
return NULL; /* FAILED */
}
if (!msi_hash_dir(ctx->msi_ctx->msi, ctx->msi_ctx->dirent, hash, 1)) {
printf("Unable to msi_handle_dir()\n");
return NULL; /* FAILED */
}
content = spc_indirect_data_content_get(hash, ctx);
return pkcs7_set_content(content);
}
/*
* Compute a simple sha1/sha256 message digest of the MSI file
* for use with a catalog file.
* [in] ctx: structure holds input and output data
* [in] md: message digest algorithm
* [returns] pointer to calculated message digest
*/
static u_char *msi_digest_calc(FILE_FORMAT_CTX *ctx, const EVP_MD *md)
{
u_char *mdbuf = NULL;
BIO *bhash = BIO_new(BIO_f_md());
if (!BIO_set_md(bhash, md)) {
printf("Unable to set the message digest of BIO\n");
BIO_free_all(bhash);
return NULL; /* FAILED */
}
BIO_push(bhash, BIO_new(BIO_s_null()));
if (!bio_hash_data(bhash, ctx->options->indata, 0, ctx->msi_ctx->fileend)) {
printf("Unable to calculate digest\n");
BIO_free_all(bhash);
return NULL; /* FAILED */
}
mdbuf = OPENSSL_malloc((size_t)EVP_MD_size(md));
BIO_gets(bhash, (char *)mdbuf, EVP_MD_size(md));
BIO_free_all(bhash);
return mdbuf; /* OK */
}
/*
* Calculate DigitalSignature and MsiDigitalSignatureEx and compare to values
* retrieved from PKCS#7 signedData.
* [in] ctx: structure holds input and output data
* [in] p7: PKCS#7 signature
* [returns] 0 on error or 1 on success
*/
static int msi_verify_digests(FILE_FORMAT_CTX *ctx, PKCS7 *p7)
{
int mdok, mdlen, mdtype = -1;
u_char mdbuf[EVP_MAX_MD_SIZE];
u_char cmdbuf[EVP_MAX_MD_SIZE];
u_char cexmdbuf[EVP_MAX_MD_SIZE];
u_char *cdigest = NULL;
const EVP_MD *md;
BIO *hash;
if (is_content_type(p7, SPC_INDIRECT_DATA_OBJID)) {
ASN1_STRING *content_val = p7->d.sign->contents->d.other->value.sequence;
const u_char *p = content_val->data;
SpcIndirectDataContent *idc = d2i_SpcIndirectDataContent(NULL, &p, content_val->length);
if (idc) {
if (idc->messageDigest && idc->messageDigest->digest && idc->messageDigest->digestAlgorithm) {
mdtype = OBJ_obj2nid(idc->messageDigest->digestAlgorithm->algorithm);
memcpy(mdbuf, idc->messageDigest->digest->data, (size_t)idc->messageDigest->digest->length);
}
SpcIndirectDataContent_free(idc);
}
}
if (mdtype == -1) {
printf("Failed to extract current message digest\n\n");
return 0; /* FAILED */
}
printf("Message digest algorithm : %s\n", OBJ_nid2sn(mdtype));
md = EVP_get_digestbynid(mdtype);
hash = BIO_new(BIO_f_md());
if (!BIO_set_md(hash, md)) {
printf("Unable to set the message digest of BIO\n");
BIO_free_all(hash);
return 0; /* FAILED */
}
BIO_push(hash, BIO_new(BIO_s_null()));
if (ctx->msi_ctx->p_msiex) {
BIO *prehash = BIO_new(BIO_f_md());
if (EVP_MD_size(md) != (int)ctx->msi_ctx->len_msiex) {
printf("Incorrect MsiDigitalSignatureEx stream data length\n\n");
BIO_free_all(hash);
BIO_free_all(prehash);
return 0; /* FAILED */
}
if (!BIO_set_md(prehash, md)) {
printf("Unable to set the message digest of BIO\n");
BIO_free_all(hash);
BIO_free_all(prehash);
return 0; /* FAILED */
}
BIO_push(prehash, BIO_new(BIO_s_null()));
print_hash("Current MsiDigitalSignatureEx ", "", (u_char *)ctx->msi_ctx->p_msiex,
(int)ctx->msi_ctx->len_msiex);
if (!msi_prehash_dir(ctx->msi_ctx->dirent, prehash, 1)) {
printf("Failed to calculate pre-hash used for MsiDigitalSignatureEx\n\n");
BIO_free_all(hash);
BIO_free_all(prehash);
return 0; /* FAILED */
}
BIO_gets(prehash, (char*)cexmdbuf, EVP_MAX_MD_SIZE);
BIO_free_all(prehash);
BIO_write(hash, (char*)cexmdbuf, EVP_MD_size(md));
print_hash("Calculated MsiDigitalSignatureEx ", "", cexmdbuf, EVP_MD_size(md));
}
if (!msi_hash_dir(ctx->msi_ctx->msi, ctx->msi_ctx->dirent, hash, 1)) {
printf("Failed to calculate DigitalSignature\n\n");
BIO_free_all(hash);
return 0; /* FAILED */
}
print_hash("Current DigitalSignature ", "", mdbuf, EVP_MD_size(md));
BIO_gets(hash, (char*)cmdbuf, EVP_MAX_MD_SIZE);
BIO_free_all(hash);
mdok = !memcmp(mdbuf, cmdbuf, (size_t)EVP_MD_size(md));
print_hash("Calculated DigitalSignature ", mdok ? "" : " MISMATCH!!!\n",
cmdbuf, EVP_MD_size(md));
if (!mdok) {
printf("Signature verification: failed\n\n");
return 0; /* FAILED */
}
cdigest = msi_digest_calc(ctx, md);
if (!cdigest) {
printf("Failed to calculate simple message digest\n\n");
return 0; /* FAILED */
}
mdlen = EVP_MD_size(EVP_get_digestbynid(mdtype));
print_hash("Calculated message digest ", "\n", cdigest, mdlen);
OPENSSL_free(cdigest);
return 1; /* OK */
}
/*
* Extract existing signature in DER format.
* [in] ctx: structure holds input and output data
* [returns] pointer to PKCS#7 structure
*/
static PKCS7 *msi_pkcs7_extract(FILE_FORMAT_CTX *ctx)
{
PKCS7 *p7;
MSI_ENTRY *ds;
if (!msi_check_file(ctx)) {
return NULL; /* FAILED, no signature */
}
ds = msi_signatures_get(ctx->msi_ctx->dirent, NULL);
if (!ds) {
printf("MSI file has no signature\n");
return NULL; /* FAILED */
}
p7 = msi_pkcs7_get_digital_signature(ctx, ds);
if (!p7) {
printf("Unable to extract existing signature\n");
return NULL; /* FAILED */
}
return p7;
}
/*
* Extract existing signature in DER format.
* Perform a sanity check for the MsiDigitalSignatureEx section.
* [in] ctx: structure holds input and output data
* [returns] pointer to PKCS#7 structure
*/
static PKCS7 *msi_pkcs7_extract_to_nest(FILE_FORMAT_CTX *ctx)
{
PKCS7 *p7;
MSI_ENTRY *ds, *dse = NULL;
if (!msi_check_file(ctx)) {
return NULL; /* FAILED, no signature */
}
ds = msi_signatures_get(ctx->msi_ctx->dirent, &dse);
if (!ds) {
printf("MSI file has no signature\n");
return NULL; /* FAILED */
}
p7 = msi_pkcs7_get_digital_signature(ctx, ds);
if (!p7) {
printf("Unable to extract existing signature\n");
return NULL; /* FAILED */
}
/* perform a sanity check for the MsiDigitalSignatureEx section */
if (!msi_check_MsiDigitalSignatureEx(ctx, dse, p7)) {
PKCS7_free(p7);
return NULL; /* FAILED */
}
return p7;
}
/*
* Remove existing signature.
* [in, out] ctx: structure holds input and output data
* [out] hash: message digest BIO (unused)
* [out] outdata: outdata file BIO
* [returns] 1 on error or 0 on success
*/
static int msi_remove_pkcs7(FILE_FORMAT_CTX *ctx, BIO *hash, BIO *outdata)
{
MSI_ENTRY *ds;
/* squash the unused parameter warning */
(void)hash;
ds = msi_signatures_get(ctx->msi_ctx->dirent, NULL);
if (!ds) {
return 1; /* FAILED, no signature */
}
if (!msi_dirent_delete(ctx->msi_ctx->dirent, digital_signature_ex,
sizeof digital_signature_ex)) {
return 1; /* FAILED */
}
if (!msi_dirent_delete(ctx->msi_ctx->dirent, digital_signature,
sizeof digital_signature)) {
return 1; /* FAILED */
}
if (!msi_file_write(ctx->msi_ctx->msi, ctx->msi_ctx->dirent,
NULL, 0, NULL, 0, outdata)) {
printf("Saving the msi file failed\n");
return 1; /* FAILED */
}
return 0; /* OK */
}
/*
* Calculate a hash (message digest) of data.
* [in, out] ctx: structure holds input and output data
* [out] hash: message digest BIO
* [out] outdata: outdata file BIO (unused)
* [returns] 1 on error or 0 on success
*/
static int msi_process_data(FILE_FORMAT_CTX *ctx, BIO *hash, BIO *outdata)
{
/* squash the unused parameter warning */
(void)outdata;
hash = msi_digest_calc_bio(ctx, hash);
if (!hash) {
return 1; /* FAILED */
}
return 0; /* OK */
}
/*
* Create a new PKCS#7 signature.
* [in, out] ctx: structure holds input and output data
* [out] hash: message digest BIO
* [returns] pointer to PKCS#7 structure
*/
static PKCS7 *msi_pkcs7_signature_new(FILE_FORMAT_CTX *ctx, BIO *hash)
{
ASN1_OCTET_STRING *content;
PKCS7 *p7 = pkcs7_create(ctx);
if (!p7) {
printf("Creating a new signature failed\n");
return NULL; /* FAILED */
}
if (!add_indirect_data_object(p7)) {
printf("Adding SPC_INDIRECT_DATA_OBJID failed\n");
PKCS7_free(p7);
return NULL; /* FAILED */
}
content = spc_indirect_data_content_get(hash, ctx);
if (!content) {
printf("Failed to get spcIndirectDataContent\n");
return NULL; /* FAILED */
}
if (!sign_spc_indirect_data_content(p7, content)) {
printf("Failed to set signed content\n");
PKCS7_free(p7);
ASN1_OCTET_STRING_free(content);
return NULL; /* FAILED */
}
ASN1_OCTET_STRING_free(content);
return p7;
}
/*
* Append signature to the outfile.
* [in, out] ctx: structure holds input and output data
* [out] outdata: outdata file BIO
* [in] p7: PKCS#7 signature
* [returns] 1 on error or 0 on success
*/
static int msi_append_pkcs7(FILE_FORMAT_CTX *ctx, BIO *outdata, PKCS7 *p7)
{
u_char *p = NULL;
int len; /* signature length */
if (((len = i2d_PKCS7(p7, NULL)) <= 0)
|| (p = OPENSSL_malloc((size_t)len)) == NULL) {
printf("i2d_PKCS memory allocation failed: %d\n", len);
return 1; /* FAILED */
}
i2d_PKCS7(p7, &p);
p -= len;
if (!msi_file_write(ctx->msi_ctx->msi, ctx->msi_ctx->dirent, p, (uint32_t)len,
ctx->msi_ctx->p_msiex, ctx->msi_ctx->len_msiex, outdata)) {
printf("Saving the msi file failed\n");
OPENSSL_free(p);
return 1; /* FAILED */
}
OPENSSL_free(p);
return 0; /* OK */
}
/*
* Free up an entire outdata BIO chain.
* [out] hash: message digest BIO
* [out] outdata: outdata file BIO
* [returns] none
*/
static void msi_bio_free(BIO *hash, BIO *outdata)
{
BIO_free_all(hash);
BIO_free_all(outdata);
}
/*
* Deallocate a FILE_FORMAT_CTX structure and MSI format specific structures,
* unmap indata file.
* [in, out] ctx: structure holds input and output data
* [out] hash: message digest BIO
* [out] outdata: outdata file BIO
* [returns] none
*/
static void msi_ctx_cleanup(FILE_FORMAT_CTX *ctx)
{
unmap_file(ctx->options->indata, ctx->msi_ctx->fileend);
msi_file_free(ctx->msi_ctx->msi);
msi_dirent_free(ctx->msi_ctx->dirent);
OPENSSL_free(ctx->msi_ctx->p_msiex);
OPENSSL_free(ctx->msi_ctx);
OPENSSL_free(ctx);
}
static int msi_is_detaching_supported(void)
{
return 1; /* OK */
}
/*
* MSI helper functions
*/
/*
* Verify mapped MSI file and create MSI format specific structure.
* [in] indata: mapped MSI file
* [in] filesize: size of MSI file
* [returns] pointer to MSI format specific structure
*/
static MSI_CTX *msi_ctx_get(char *indata, uint32_t filesize)
{
MSI_ENTRY *root;
MSI_FILE *msi;
MSI_DIRENT *dirent;
MSI_CTX *msi_ctx;
msi = msi_file_new(indata, filesize);
if (!msi) {
printf("Failed to parse MSI_FILE struct\n");
return NULL; /* FAILED */
}
root = msi_root_entry_get(msi);
if (!root) {
printf("Failed to get file entry\n");
msi_file_free(msi);
return NULL; /* FAILED */
}
if (!msi_dirent_new(msi, root, NULL, &(dirent))) {
printf("Failed to parse MSI_DIRENT struct\n");
msi_file_free(msi);
return NULL; /* FAILED */
}
msi_ctx = OPENSSL_zalloc(sizeof(MSI_CTX));
msi_ctx->msi = msi;
msi_ctx->dirent = dirent;
msi_ctx->fileend = filesize;
return msi_ctx; /* OK */
}
static PKCS7 *msi_pkcs7_get_digital_signature(FILE_FORMAT_CTX *ctx, MSI_ENTRY *ds)
{
PKCS7 *p7 = NULL;
const u_char *blob;
char *p;
uint32_t len = GET_UINT32_LE(ds->size);
if (len == 0 || len >= MAXREGSECT) {
printf("Corrupted DigitalSignature stream length 0x%08X\n", len);
return NULL; /* FAILED */
}
p = OPENSSL_malloc((size_t)len);
if (!msi_file_read(ctx->msi_ctx->msi, ds, 0, p, len)) {
printf("DigitalSignature stream data error\n");
OPENSSL_free(p);
return NULL;
}
blob = (u_char *)p;
p7 = d2i_PKCS7(NULL, &blob, len);
OPENSSL_free(p);
if (!p7) {
printf("Failed to extract PKCS7 data\n");
return NULL;
}
return p7;
}
/* Get absolute address from sector and offset */
static const u_char *sector_offset_to_address(MSI_FILE *msi, uint32_t sector, uint32_t offset)
{
if (sector >= MAXREGSECT || offset >= msi->m_sectorSize
|| (msi->m_bufferLen - offset) / msi->m_sectorSize <= sector) {
printf("Corrupted file\n");
return NULL; /* FAILED */
}
return msi->m_buffer + (sector + 1) * msi->m_sectorSize + offset;
}
static uint32_t get_fat_sector_location(MSI_FILE *msi, uint32_t fatSectorNumber)
{
uint32_t entriesPerSector, difatSectorLocation, fatSectorLocation;
const u_char *address;
if (fatSectorNumber < DIFAT_IN_HEADER) {
return LE_UINT32(msi->m_hdr->headerDIFAT[fatSectorNumber]);
} else {
fatSectorNumber -= DIFAT_IN_HEADER;
entriesPerSector = msi->m_sectorSize / 4 - 1;
difatSectorLocation = msi->m_hdr->firstDIFATSectorLocation;
while (fatSectorNumber >= entriesPerSector) {
fatSectorNumber -= entriesPerSector;
address = sector_offset_to_address(msi, difatSectorLocation, msi->m_sectorSize - 4);
if (!address) {
printf("Failed to get a next sector address\n");
return NOSTREAM; /* FAILED */
}
difatSectorLocation = GET_UINT32_LE(address);
}
address = sector_offset_to_address(msi, difatSectorLocation, fatSectorNumber * 4);
if (!address) {
printf("Failed to get a next sector address\n");
return NOSTREAM; /* FAILED */
}
fatSectorLocation = GET_UINT32_LE(address);
if (fatSectorLocation == 0 || fatSectorLocation >= FREESECT) {
printf("Get corrupted sector location 0x%08X\n", fatSectorLocation);
return NOSTREAM; /* FAILED */
}
return fatSectorLocation;
}
}
/* Lookup FAT */
static uint32_t get_next_sector(MSI_FILE *msi, uint32_t sector)
{
const u_char *address;
uint32_t nextSectorLocation;
uint32_t entriesPerSector = msi->m_sectorSize / 4;
uint32_t fatSectorNumber = sector / entriesPerSector;
uint32_t fatSectorLocation = get_fat_sector_location(msi, fatSectorNumber);
if (fatSectorLocation == NOSTREAM) {
printf("Failed to get a fat sector location\n");
return NOSTREAM; /* FAILED */
}
address = sector_offset_to_address(msi, fatSectorLocation, sector % entriesPerSector * 4);
if (!address) {
printf("Failed to get a next sector address\n");
return NOSTREAM; /* FAILED */
}
nextSectorLocation = GET_UINT32_LE(address);
if (nextSectorLocation == 0 || nextSectorLocation >= FREESECT) {
printf("Get corrupted sector location 0x%08X\n", nextSectorLocation);
return NOSTREAM; /* FAILED */
}
return nextSectorLocation;
}
/* Locate the final sector/offset when original offset expands multiple sectors */
static int locate_final_sector(MSI_FILE *msi, uint32_t sector, uint32_t offset, uint32_t *finalSector, uint32_t *finalOffset)
{
while (offset >= msi->m_sectorSize) {
offset -= msi->m_sectorSize;
sector = get_next_sector(msi, sector);
if (sector == NOSTREAM) {
printf("Failed to get a next sector\n");
return 0; /* FAILED */
}
}
*finalSector = sector;
*finalOffset = offset;
return 1; /* OK */
}
/* Get absolute address from mini sector and offset */
static const u_char *mini_sector_offset_to_address(MSI_FILE *msi, uint32_t sector, uint32_t offset)
{
if (sector >= MAXREGSECT || offset >= msi->m_minisectorSize ||
(msi->m_bufferLen - offset) / msi->m_minisectorSize <= sector) {
printf("Corrupted file\n");
return NULL; /* FAILED */
}
if (!locate_final_sector(msi, msi->m_miniStreamStartSector, sector * msi->m_minisectorSize + offset, §or, &offset)) {
printf("Failed to locate a final sector\n");
return NULL; /* FAILED */
}
return sector_offset_to_address(msi, sector, offset);
}
/*
* Copy as many as possible in each step
* copylen typically iterate as: msi->m_sectorSize - offset --> msi->m_sectorSize --> msi->m_sectorSize --> ... --> remaining
*/
static int read_stream(MSI_FILE *msi, uint32_t sector, uint32_t offset, char *buffer, uint32_t len)
{
if (!locate_final_sector(msi, sector, offset, §or, &offset)) {
printf("Failed to locate a final sector\n");
return 0; /* FAILED */
}
while (len > 0) {
const u_char *address;
uint32_t copylen;
address = sector_offset_to_address(msi, sector, offset);
if (!address) {
printf("Failed to get a next sector address\n");
return 0; /* FAILED */
}
copylen = MIN(len, msi->m_sectorSize - offset);
if (msi->m_buffer + msi->m_bufferLen < address + copylen) {
printf("Corrupted file\n");
return 0; /* FAILED */
}
memcpy(buffer, address, copylen);
buffer += copylen;
len -= copylen;
sector = get_next_sector(msi, sector);
if (sector == 0) {
printf("Failed to get a next sector\n");
return 0; /* FAILED */
}
offset = 0;
}
return 1; /* OK */
}
/* Lookup miniFAT */
static uint32_t get_next_mini_sector(MSI_FILE *msi, uint32_t miniSector)
{
uint32_t sector, offset, nextMiniSectorLocation;
const u_char *address;
if (!locate_final_sector(msi, msi->m_hdr->firstMiniFATSectorLocation, miniSector * 4, §or, &offset)) {
printf("Failed to locate a final sector\n");
return NOSTREAM; /* FAILED */
}
address = sector_offset_to_address(msi, sector, offset);
if (!address) {
printf("Failed to get a next mini sector address\n");
return NOSTREAM; /* FAILED */
}
nextMiniSectorLocation = GET_UINT32_LE(address);
if (nextMiniSectorLocation == 0 || nextMiniSectorLocation >= FREESECT) {
printf("Get corrupted sector location 0x%08X\n", nextMiniSectorLocation);
return NOSTREAM; /* FAILED */
}
return nextMiniSectorLocation;
}
static int locate_final_mini_sector(MSI_FILE *msi, uint32_t sector, uint32_t offset, uint32_t *finalSector, uint32_t *finalOffset)
{
while (offset >= msi->m_minisectorSize) {
offset -= msi->m_minisectorSize;
sector = get_next_mini_sector(msi, sector);
if (sector == NOSTREAM) {
printf("Failed to get a next mini sector\n");
return 0; /* FAILED */
}
}
*finalSector = sector;
*finalOffset = offset;
return 1; /* OK */
}
/* Same logic as "read_stream" except that use mini stream functions instead */
static int read_mini_stream(MSI_FILE *msi, uint32_t sector, uint32_t offset, char *buffer, uint32_t len)
{
if (!locate_final_mini_sector(msi, sector, offset, §or, &offset)) {
printf("Failed to locate a final mini sector\n");
return 0; /* FAILED */
}
while (len > 0) {
const u_char *address;
uint32_t copylen;
address = mini_sector_offset_to_address(msi, sector, offset);
if (!address) {
printf("Failed to get a next mini sector address\n");
return 0; /* FAILED */
}
copylen = MIN(len, msi->m_minisectorSize - offset);
if (msi->m_buffer + msi->m_bufferLen < address + copylen) {
printf("Corrupted file\n");
return 0; /* FAILED */
}
memcpy(buffer, address, copylen);
buffer += copylen;
len -= copylen;
sector = get_next_mini_sector(msi, sector);
if (sector == NOSTREAM) {
printf("Failed to get a next mini sector\n");
return 0; /* FAILED */
}
offset = 0;
}
return 1; /* OK */
}
/*
* Get file (stream) data start with "offset".
* The buffer must have enough space to store "len" bytes. Typically "len" is derived by the steam length.
*/
static int msi_file_read(MSI_FILE *msi, MSI_ENTRY *entry, uint32_t offset, char *buffer, uint32_t len)
{
if (len < msi->m_hdr->miniStreamCutoffSize) {
if (!read_mini_stream(msi, entry->startSectorLocation, offset, buffer, len))
return 0; /* FAILED */
} else {
if (!read_stream(msi, entry->startSectorLocation, offset, buffer, len))
return 0; /* FAILED */
}
return 1; /* OK */
}
/* Parse MSI_FILE_HDR struct */
static MSI_FILE_HDR *parse_header(char *data)
{
MSI_FILE_HDR *header = (MSI_FILE_HDR *)OPENSSL_malloc(HEADER_SIZE);
/* initialise 512 bytes */
memset(header, 0, sizeof(MSI_FILE_HDR));