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Peter McGoron 2023-12-09 10:58:59 -05:00
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Apache License
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---------------------
Windows Local Backup
---------------------
Windows local backup system. Supports anything Sqlite3 supports.
Tested on x86 TCC for Windows XP.
Backups are stored in a SQLite database. Each backup is timestamped
at the time of execution, with an optional name.
Each file in the backup has it's SHA256 sum included. If a file has
an identical SHA256 sum, only one copy of the file is stored. The
relative directory of each file is stored.
-----
Notes
-----
Do not run backups while programs are writing to things or your
program might crash. The backup program should still work fine.

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#include "sha-256.h"
#define TOTAL_LEN_LEN 8
/*
* Comments from pseudo-code at https://en.wikipedia.org/wiki/SHA-2 are reproduced here.
* When useful for clarification, portions of the pseudo-code are reproduced here too.
*/
/*
* @brief Rotate a 32-bit value by a number of bits to the right.
* @param value The value to be rotated.
* @param count The number of bits to rotate by.
* @return The rotated value.
*/
static inline uint32_t right_rot(uint32_t value, unsigned int count)
{
/*
* Defined behaviour in standard C for all count where 0 < count < 32, which is what we need here.
*/
return value >> count | value << (32 - count);
}
/*
* @brief Update a hash value under calculation with a new chunk of data.
* @param h Pointer to the first hash item, of a total of eight.
* @param p Pointer to the chunk data, which has a standard length.
*
* @note This is the SHA-256 work horse.
*/
static inline void consume_chunk(uint32_t *h, const uint8_t *p)
{
unsigned i, j;
uint32_t ah[8];
/* Initialize working variables to current hash value: */
for (i = 0; i < 8; i++)
ah[i] = h[i];
/*
* The w-array is really w[64], but since we only need 16 of them at a time, we save stack by
* calculating 16 at a time.
*
* This optimization was not there initially and the rest of the comments about w[64] are kept in their
* initial state.
*/
/*
* create a 64-entry message schedule array w[0..63] of 32-bit words (The initial values in w[0..63]
* don't matter, so many implementations zero them here) copy chunk into first 16 words w[0..15] of the
* message schedule array
*/
uint32_t w[16];
/* Compression function main loop: */
for (i = 0; i < 4; i++) {
for (j = 0; j < 16; j++) {
if (i == 0) {
w[j] =
(uint32_t)p[0] << 24 | (uint32_t)p[1] << 16 | (uint32_t)p[2] << 8 | (uint32_t)p[3];
p += 4;
} else {
/* Extend the first 16 words into the remaining 48 words w[16..63] of the
* message schedule array: */
const uint32_t s0 = right_rot(w[(j + 1) & 0xf], 7) ^ right_rot(w[(j + 1) & 0xf], 18) ^
(w[(j + 1) & 0xf] >> 3);
const uint32_t s1 = right_rot(w[(j + 14) & 0xf], 17) ^
right_rot(w[(j + 14) & 0xf], 19) ^ (w[(j + 14) & 0xf] >> 10);
w[j] = w[j] + s0 + w[(j + 9) & 0xf] + s1;
}
const uint32_t s1 = right_rot(ah[4], 6) ^ right_rot(ah[4], 11) ^ right_rot(ah[4], 25);
const uint32_t ch = (ah[4] & ah[5]) ^ (~ah[4] & ah[6]);
/*
* Initialize array of round constants:
* (first 32 bits of the fractional parts of the cube roots of the first 64 primes 2..311):
*/
static const uint32_t k[] = {
0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4,
0xab1c5ed5, 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe,
0x9bdc06a7, 0xc19bf174, 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f,
0x4a7484aa, 0x5cb0a9dc, 0x76f988da, 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967, 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc,
0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, 0xa2bfe8a1, 0xa81a664b,
0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070, 0x19a4c116,
0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7,
0xc67178f2};
const uint32_t temp1 = ah[7] + s1 + ch + k[i << 4 | j] + w[j];
const uint32_t s0 = right_rot(ah[0], 2) ^ right_rot(ah[0], 13) ^ right_rot(ah[0], 22);
const uint32_t maj = (ah[0] & ah[1]) ^ (ah[0] & ah[2]) ^ (ah[1] & ah[2]);
const uint32_t temp2 = s0 + maj;
ah[7] = ah[6];
ah[6] = ah[5];
ah[5] = ah[4];
ah[4] = ah[3] + temp1;
ah[3] = ah[2];
ah[2] = ah[1];
ah[1] = ah[0];
ah[0] = temp1 + temp2;
}
}
/* Add the compressed chunk to the current hash value: */
for (i = 0; i < 8; i++)
h[i] += ah[i];
}
/*
* Public functions. See header file for documentation.
*/
void sha_256_init(struct Sha_256 *sha_256, uint8_t hash[SIZE_OF_SHA_256_HASH])
{
sha_256->hash = hash;
sha_256->chunk_pos = sha_256->chunk;
sha_256->space_left = SIZE_OF_SHA_256_CHUNK;
sha_256->total_len = 0;
/*
* Initialize hash values (first 32 bits of the fractional parts of the square roots of the first 8 primes
* 2..19):
*/
sha_256->h[0] = 0x6a09e667;
sha_256->h[1] = 0xbb67ae85;
sha_256->h[2] = 0x3c6ef372;
sha_256->h[3] = 0xa54ff53a;
sha_256->h[4] = 0x510e527f;
sha_256->h[5] = 0x9b05688c;
sha_256->h[6] = 0x1f83d9ab;
sha_256->h[7] = 0x5be0cd19;
}
void sha_256_write(struct Sha_256 *sha_256, const void *data, size_t len)
{
sha_256->total_len += len;
/*
* The following cast is not necessary, and could even be considered as poor practice. However, it makes this
* file valid C++, which could be a good thing for some use cases.
*/
const uint8_t *p = (const uint8_t *)data;
while (len > 0) {
/*
* If the input chunks have sizes that are multiples of the calculation chunk size, no copies are
* necessary. We operate directly on the input data instead.
*/
if (sha_256->space_left == SIZE_OF_SHA_256_CHUNK && len >= SIZE_OF_SHA_256_CHUNK) {
consume_chunk(sha_256->h, p);
len -= SIZE_OF_SHA_256_CHUNK;
p += SIZE_OF_SHA_256_CHUNK;
continue;
}
/* General case, no particular optimization. */
const size_t consumed_len = len < sha_256->space_left ? len : sha_256->space_left;
memcpy(sha_256->chunk_pos, p, consumed_len);
sha_256->space_left -= consumed_len;
len -= consumed_len;
p += consumed_len;
if (sha_256->space_left == 0) {
consume_chunk(sha_256->h, sha_256->chunk);
sha_256->chunk_pos = sha_256->chunk;
sha_256->space_left = SIZE_OF_SHA_256_CHUNK;
} else {
sha_256->chunk_pos += consumed_len;
}
}
}
uint8_t *sha_256_close(struct Sha_256 *sha_256)
{
uint8_t *pos = sha_256->chunk_pos;
size_t space_left = sha_256->space_left;
uint32_t *const h = sha_256->h;
/*
* The current chunk cannot be full. Otherwise, it would already have been consumed. I.e. there is space left for
* at least one byte. The next step in the calculation is to add a single one-bit to the data.
*/
*pos++ = 0x80;
--space_left;
/*
* Now, the last step is to add the total data length at the end of the last chunk, and zero padding before
* that. But we do not necessarily have enough space left. If not, we pad the current chunk with zeroes, and add
* an extra chunk at the end.
*/
if (space_left < TOTAL_LEN_LEN) {
memset(pos, 0x00, space_left);
consume_chunk(h, sha_256->chunk);
pos = sha_256->chunk;
space_left = SIZE_OF_SHA_256_CHUNK;
}
const size_t left = space_left - TOTAL_LEN_LEN;
memset(pos, 0x00, left);
pos += left;
size_t len = sha_256->total_len;
pos[7] = (uint8_t)(len << 3);
len >>= 5;
int i;
for (i = 6; i >= 0; --i) {
pos[i] = (uint8_t)len;
len >>= 8;
}
consume_chunk(h, sha_256->chunk);
/* Produce the final hash value (big-endian): */
int j;
uint8_t *const hash = sha_256->hash;
for (i = 0, j = 0; i < 8; i++) {
hash[j++] = (uint8_t)(h[i] >> 24);
hash[j++] = (uint8_t)(h[i] >> 16);
hash[j++] = (uint8_t)(h[i] >> 8);
hash[j++] = (uint8_t)h[i];
}
return sha_256->hash;
}
void calc_sha_256(uint8_t hash[SIZE_OF_SHA_256_HASH], const void *input, size_t len)
{
struct Sha_256 sha_256;
sha_256_init(&sha_256, hash);
sha_256_write(&sha_256, input, len);
(void)sha_256_close(&sha_256);
}

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#ifndef SHA_256_H
#define SHA_256_H
#include <stdint.h>
#include <string.h>
#ifdef __cplusplus
extern "C" {
#endif
/*
* @brief Size of the SHA-256 sum. This times eight is 256 bits.
*/
#define SIZE_OF_SHA_256_HASH 32
/*
* @brief Size of the chunks used for the calculations.
*
* @note This should mostly be ignored by the user, although when using the streaming API, it has an impact for
* performance. Add chunks whose size is a multiple of this, and you will avoid a lot of superfluous copying in RAM!
*/
#define SIZE_OF_SHA_256_CHUNK 64
/*
* @brief The opaque SHA-256 type, that should be instantiated when using the streaming API.
*
* @note Although the details are exposed here, in order to make instantiation easy, you should refrain from directly
* accessing the fields, as they may change in the future.
*/
struct Sha_256 {
uint8_t *hash;
uint8_t chunk[SIZE_OF_SHA_256_CHUNK];
uint8_t *chunk_pos;
size_t space_left;
size_t total_len;
uint32_t h[8];
};
/*
* @brief The simple SHA-256 calculation function.
* @param hash Hash array, where the result is delivered.
* @param input Pointer to the data the hash shall be calculated on.
* @param len Length of the input data, in byte.
*
* @note If all of the data you are calculating the hash value on is available in a contiguous buffer in memory, this is
* the function you should use.
*
* @note If either of the passed pointers is NULL, the results are unpredictable.
*/
void calc_sha_256(uint8_t hash[SIZE_OF_SHA_256_HASH], const void *input, size_t len);
/*
* @brief Initialize a SHA-256 streaming calculation.
* @param sha_256 A pointer to a SHA-256 structure.
* @param hash Hash array, where the result will be delivered.
*
* @note If all of the data you are calculating the hash value on is not available in a contiguous buffer in memory, this is
* where you should start. Instantiate a SHA-256 structure, for instance by simply declaring it locally, make your hash
* buffer available, and invoke this function. Once a SHA-256 hash has been calculated (see further below) a SHA-256
* structure can be initialized again for the next calculation.
*
* @note If either of the passed pointers is NULL, the results are unpredictable.
*/
void sha_256_init(struct Sha_256 *sha_256, uint8_t hash[SIZE_OF_SHA_256_HASH]);
/*
* @brief Stream more input data for an on-going SHA-256 calculation.
* @param sha_256 A pointer to a previously initialized SHA-256 structure.
* @param data Pointer to the data to be added to the calculation.
* @param len Length of the data to add, in byte.
*
* @note This function may be invoked an arbitrary number of times between initialization and closing, but the maximum
* data length is limited by the SHA-256 algorithm: the total number of bits (i.e. the total number of bytes times
* eight) must be representable by a 64-bit unsigned integer. While that is not a practical limitation, the results are
* unpredictable if that limit is exceeded.
*
* @note This function may be invoked on empty data (zero length), although that obviously will not add any data.
*
* @note If either of the passed pointers is NULL, the results are unpredictable.
*/
void sha_256_write(struct Sha_256 *sha_256, const void *data, size_t len);
/*
* @brief Conclude a SHA-256 streaming calculation, making the hash value available.
* @param sha_256 A pointer to a previously initialized SHA-256 structure.
* @return Pointer to the hash array, where the result is delivered.
*
* @note After this function has been invoked, the result is available in the hash buffer that initially was provided. A
* pointer to the hash value is returned for convenience, but you should feel free to ignore it: it is simply a pointer
* to the first byte of your initially provided hash array.
*
* @note If the passed pointer is NULL, the results are unpredictable.
*
* @note Invoking this function for a calculation with no data (the writing function has never been invoked, or it only
* has been invoked with empty data) is legal. It will calculate the SHA-256 value of the empty string.
*/
uint8_t *sha_256_close(struct Sha_256 *sha_256);
#ifdef __cplusplus
}
#endif
#endif

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#include <windows.h>
#include <stdlib.h>
#include <tchar.h>
#include "sqlite3.h"
#include "sha-2/sha-256.h"
#define SHASIZ SIZE_OF_SHA_256_HASH
/* TODO: "\\?\" trick?
* Windows limits path lengths to 260 characters. Explorer on Windows XP
* has this issue too.
*
* UTF issues?
*/
/*************************************************************************
* Compatability defines for non-Unicode systems
************************************************************************/
#ifdef UNICODE
# define ENCODING SQLITE3_UTF16
# define sqlite3_open_U sqlite3_open16
# define sqlite3_errmsg_U sqlite3_errmsg16
# define sqlite3_bind_text_U sqlite3_bind_text16
#else
# define ENCODING SQLITE3_UTF8
# define sqlite3_open_U sqlite3_open
# define sqlite3_errmsg_U sqlite3_errmsg
# define sqlite3_bind_text_U sqlite3_bind_text
#endif
/****************
* Globals
***************/
sqlite3 *g_db = NULL;
int g_verbose = 0;
sqlite_int64 g_backup_id = -1;
/********************
* Utility Functions
*******************/
static void _log(TCHAR *msg, ...)
{
va_list va;
if (g_verbose) {
va_start(va, emsg);
_tvprintf(emsg, va);
va_end(va);
}
}
/* String literals only */
#define log(msg, ...) _log(TEXT(msg), __VA_ARGS__)
static void _die(TCHAR *emsg, ...)
{
va_list va;
va_start(va, emsg);
_tvprintf(emsg, va);
va_end(va);
sqlite3_close(g_db);
exit(1);
}
/* String literals only */
#define die(emsg, ...) _die(TEXT(emsg), __VA_ARGS__)
/**********************************
* Database constants
*********************************/
/* 'wlb' in ASCII */
#define UPPER_VERSION 0x776c62
#define CUR_VERSION 0x776c6201
#define S(s) #s
#define INIT_SCRIPT "\
BEGIN; \
PRAGMA user_version = " S(CUR_VERSION) ";\
CREATE TABLE chunks (\
rowid INTEGER PRIMARY KEY, \
sha256 TEXT UNIQUE NOT NULL, \
data BLOB NOT NULL\
); \
CREATE TABLE backup_ids (\
ts TEXT UNIQUE NOT NULL,\
rowid INTEGER PRIMARY KEY\
); \
CREATE TABLE backups (\
backup INTEGER NOT NULL REFERENCES backup_ids ON DELETE CASCADE, \
path TEXT NOT NULL, \
chunk INTEGER NOT NULL REFERENCES chunks ON DELETE RESTRICT\
); \
CREATE INDEX backups_paths ON backups (path); \
CREATE INDEX backups_backup ON backups (backup); \
CREATE INDEX backups_chunk ON backups (chunk);\
COMMIT;"
/* Check if the database version is correct. If it is not correct
* and the create flag is enabled, then initialize a new database.
*/
static void check_db_version(int did_not_exist)
{
int user_version;
sqlite3_stmt *stmt;
/* DB did not exist beforehand: initialize DB */
if (did_not_exist) {
if (sqlite3_exec(g_db, INIT_SCRIPT, NULL, NULL, NULL) != SQLITE_OK)
die("Error initializing database: %s\n",
sqlite3_errmsg_U(g_db));
log("Intialized database\n");
return;
}
/* DB existed beforehand: do version check */
if (sqlite3_prepare_v2(g_db, "PRAGMA user_version;", -1, &stmt, NULL)
!= SQLITE_OK)
die("Error preparing user version check: %s\n",
sqlite3_errmsg_U(g_db));
if (sqlite3_step(stmt) != SQLITE_ROW)
die("Error executing user version check: %s\n",
sqlite3_errmsg_U(g_db));
user_version = sqlite3_column_int(stmt, 0);
sqlite3_finalize(stmt);
if (user_version != CUR_VERSION) {
die("Bad DB version found (expected %d), got %d\n",
CUR_VERSION & 0xFF, user_version & 0xFF);
}
}
/* Initialize the backup ID used in this session.
* This is only called if the user requests an archive of a directory.
*/
static void initialize_backup_id(void)
{
sqlite3_stmt *stmt;
if (sqlite3_prepare(g_db,
"INSERT INTO backup_ids (ts) VALUES (datetime()) RETURNING rowid;",
-1, &stmt, NULL) != SQLITE_OK) {
die("failed to prepare inserting timestamp: %s\n",
sqlite3_errmsg_U(g_db));
}
if (sqlite3_step(stmt) != SQLITE_ROW)
die("failed to insert timestamp: %s\n",
sqlite3_errmsg_U(g_db));
g_backup_id = sqlite3_column_int64(stmt, 0);
sqlite3_finalize(stmt);
}
/* Opens the DB and initializes it if it did not exist. */
static void open_db(TCHAR *fn)
{
int did_not_exist = GetFileAttributes(fn)
== INVALID_FILE_ATTRIBUTES;
char *errmsg;
if (sqlite3_open_U(fn, &g_db) != SQLITE_OK)
die("Error opening database %s: %s\n", argv[i],
sqlite3_errmsg_U(g_db));
check_db_version(did_not_exist);
/* Store current timestamp */
if (sqlite3_exec(g_db, "BEGIN;" NULL, NULL, &errmsg) != SQLITE_OK)
die("failed to begin transaction: %s\n", errmsg);
}
/* Insert a backup record into the database.
*
* This part occurs after the file data has been inserted or identified
* by SHA256 hash.
*/
static int insert_backup_record(TCHAR *name, sqlite_int64 chunk_id)
{
sqlite3_stmt *stmt;
int r = 0;
if (sqlite3_prepare(g_db,
"INSERT INTO backups (backup, path, chunk) VALUES (?,?,?);",
-1, &stmt, NULL) != SQLITE_OK) {
_tprintf("Could not prepare backup insert statement for %s: %s\n",
name, sqlite3_errmsg_U(g_db));
return 0;
}
if (sqlite3_bind_int64(stmt, 1, g_backup_id) != SQLITE_OK) {
_tprintf("Could not bind backup id for %s: %s\n", name,
sqlite3_errmsg_U(g_db));
goto end;
}
if (sqlite3_bind_text_U(stmt, 2, name) != SQLITE_OK) {
_tprintf("Could not bind path for %s: %s\n", name,
sqlite3_errmsg_U(g_db));
goto end;
}
if (sqlite3_bind_int64(stmt, 3, chunk_id) != SQLITE_OK) {
_tprintf("Could not bind chunk for %s: %s\n", name,
sqlite3_errmsg_U(g_db));
goto end;
}
if (sqlite3_step(stmt) != SQLITE_DONE) {
_tprintf("Error in inserting chunk for %s: %s\n", name,
sqlite3_errmsg_U(g_db));
goto end;
}
r = 1;
end:
sqlite3_finalize(stmt);
return r;
}
/* Write a file to a BLOB in ``chunks`` at row ``rowid``.
*
* Returns 0 on failure and 1 on success.
*/
static int write_chunk(TCHAR *name, HANDLE f, sqlite_int64 rowid)
{
sqlite3_blob *blob;
char buf[4096];
DWORD read = 0;
int has_written = 0;
int r = 0;
if (sqlite3_blob_open(g_db, "main", "chunks", "data", rowid, 1,
&blob) != SQLITE_OK) {
_tprintf("Could not open BLOB to write chunk for %s: %s\n",
name, sqlite3_errmsg_U(g_db));
return 0;
}
for (;;) {
if (ReadFile(f, buf, sizeof(buf), &read, NULL) == FALSE) {
_tprintf("failed to read in %s for sha256 calculation\n",
name);
goto end;
}
if (read == 0)
break;
if (sqlite3_blob_write(g_db, buf, read, has_written)
!= SQLITE_OK) {
_tprintf("Could not write to BLOB for %s: %s\n",
name, sqlite3_errmsg_U(g_db));
goto end;
}
has_written += read;
}
r = 1;
end:
sqlite3_blob_close(blob);
return r;
}
/* Insert a chunk with a specified SHA256 checksum into the database.
*
* Returns 1 on success, 0 on failure. On success, ``rowid`` contains
* the row in ``chunks`` that contains the data of ``f``.
*/
static int insert_chunk(TCHAR *name, HANDLE f, sqlite_int64 *rowid,
uint8_t sha256[SHASIZ])
{
LARGE_INTEGER fsize = 0;
sqlite3_stmt *stmt;
int r = 0;
if (SetFilePointer(f, 0, NULL, FILE_BEGIN)
== INVALID_SET_FILE_POINTER) {
_tprintf("rewind for %s failed\n", name);
return 0;
}
if (GetFileSizeEx(f, &fsize) == 0) {
_tprintf("Could not get the file size of %s\n", name);
return 0;
}
/* Chunks are fixed size in SQLite. They need to be pre-allocated
* with the size of a file before a file can be written to it.
*/
if (sqlite3_prepare(g_db,
"INSERT INTO chunks (sha256, data) VALUES (hex(?), zeroblob(?)) RETURNING rowid;",
-1, stmt, NULL) != SQLITE_OK) {
_tprintf("Could not prepare chunk insertion for %s: %s\n",
name, sqlite3_errmsg_U(g_db));
return 0;
}
if (sqlite3_bind_blob(stmt, 1, sha256, SHASIZ, SQLITE_TRANSIENT)
!= SQLITE_OK) {
_tprintf("Could not bind sha256 to statement for %s: %s\n",
name, sqlite3_errmsg_U(g_db));
goto finalize;
}
if (sqlite3_bind_int64(stmt, 2, fsize) != SQLITE_OK) {
_tprintf("Could not bind file size to statement for %s: %s\n",
name, sqlite3_errmsg_U(g_db));
goto finalize;
}
if (sqlite3_step(&stmt) != SQLITE_ROW)
_tprintf("Could not step chunk insertion statement for %s: %s\n",
name, sqlite3_errmsg_U(g_db));
goto finalize;
}
*rowid = sqlite3_column_int64(stmt, 0);
r = write_chunk(name, f, *rowid);
finalize:
sqlite3_finalize(stmt);
return r;
}
/* Check if the SHA256 checksum already exists in the database.
*
* If the checksum exists, ``rowid`` is filled with the row in ``chunks``
* that contains that sha256 sum. If it does not exist, then ``rowid``
* contains ``-1``.
*
* Returns 0 if an error occured, and 1 if no error occured.
*/
static int check_sha256(TCHAR *name, uint8_t sha256[SHASIZ],
sqlite_int64 *rowid)
{
sqlite3_stmt *stmt;
int r = 0;
/* Since ``sha256`` is binary, use ``hex`` to convert the binary
* string to a text representation.
*/
if (sqlite3_prepare_v2(g_db,
"SELECT rowid FROM chunks WHERE sha256 = hex(?);",
-1, &stmt, NULL) != SQLITE_OK) {
_tprintf("failed to prepare sha256 statement for %s: %s\n",
name, sqlite_errmsg_U(g_db));
goto end;
}
if (sqlite3_bind_blob(&stmt, 1, sha256, SHASIZ, SQLITE_TRANSIENT)
!= SQLITE_OK) {
_tprintf("failed to bind sha256 value for %s: %s\n",
name, sqlite_errmsg_U(g_db));
goto end;
}
switch (sqlite3_step(&stmt)) {
case SQLITE_ROW:
/* there is a sha256 value */
*rowid = sqlite3_column_int(stmt, 0);
break;
case SQLITE_DONE:
/* The chunk was never entered */
*rowid = -1;
break;
}
r = 1;
end:
sqlite3_finalize(stmt);
return r;
}
/* Calculate the SHA256 checksum of the file in ``f``, and place a binary
* representation of the checksum into ``shastr``.
*
* Returns 0 if there was an error, 1 for success.
*/
static int calculate_sha256(TCHAR *name, HANDLE f, uint8_t sha256[SHASIZ])
{
DWORD read = 0;
uint8_t buf[SIZE_OF_SHA_256_CHUNK * 64];
struct Sha_256 sha_state;
int i;
sha_256_init(&sha_state, sha256);
for (;;) {
if (ReadFile(f, buf, sizeof(buf), &read, NULL) == FALSE) {
_tprintf("failed to read in %s for sha256 calculation\n",
name);
return 0;
}
/* ReadFile() reads 0 bytes on EOF. */
if (read == 0)
break;
sha_256_write(&sha_state, buf, read);
}
sha_256_close(&sha_state);
return 1;
}
/* Archive a file. */
static void archive_file(TCHAR *name)
{
HANDLE f;
sqlite_int64 chunks_rowid = -1;
uint8_t sha256[SHASIZ];
char *errstr;
int success = 0;
if (sqlite3_exec(g_db, "SAVEPOINT file;", NULL, NULL, &errstr)
!= SQLITE_OK)
die("failed to initialize file savepoint: %s\n", errstr);
f = CreateFile(name, GENERIC_READ, FILE_SHARE_READ, NULL,
OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
if (f == INVALID_HANDLE_VALUE) {
_tprintf("could not open %s\n", name);
goto end;
}
if (!calculate_sha256(name, f, sha256))
goto end;
if (!check_sha256(sha256, &chunks_rowid))
goto end;
if (chunks_rowid < 0) {
if (!insert_chunk(name, f, &chunks_rowid, sha256))
goto end;
}
if (!insert_backup_record(name, chunks_rowid))
goto end;
success = 1;
log("Archived %s\n", name);
end:
if (sqlite3_exec(g_db, success ? "RELEASE file;" : "ROLLBACK TO file;", NULL, NULL,
&errstr) != SQLITE_OK)
die("failed to rollback file savepoint: %s\n", errstr);
CloseHandle(f);
}
/* Recursively archive a directory. */
static void archive_directory(TCHAR *dirname)
{
WIN32_FIND_DATA fdata;
HANDLE dhandle;
TCHAR pathname[PATH_MAX];
dhandle = FindFirstFile(dirname, &fdata);
if (dhandle == INVALID_HANDLE_VALUE) {
_tprintf("Failed to open directory %s\n", dirname);
return;
}
do {
/* Windows versions prior to 11 (!) include _snprintf() as
* a non-standard version of snprintf(). _snprintf() will
* return -1 if the string does not fit in the buffer.
*/
if (_sntprintf(pathname, PATH_MAX, "%s\\%s", dirname,
fdata.cFileName) < 0) {
_tprintf("Pathname for %s\\%s too long\n", dirname,
fdata.cFileName);
continue;
}
if (fdata.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
archive_directory(pathname);
else
archive_file(pathname);
} while (FindNextFile(dhandle, &fdata) != 0);
FindClose(dhandle);
}
/* Check if the path is a file or a directory, and either archive
* the file or archive the entire directory recursively. */
static void archive_file_or_directory(TCHAR *name)
{
DWORD attr = GetFileAttributes(fn);
if (attr == INVALID_FILE_ATTRIBUTES) {
_tprintf(TEXT("failed to open %s\n"), name);
return;
}
if (g_backup_id < 0)
initialize_backup_id();
if (attr & FILE_ATTRIBUTE_DIRECTORY)
archive_directory(name);
else
archive_file(name);
}
/* Print instructions to console and exit. */
static void usage(void)
{
_tprintf(TEXT("\nwlb [\\V] [\\H] [\\D DBNAME] [\\A DIRECTORIES...]\n"));
_tprintf(TEXT("\\V: Verbose\n"));
_tprintf(TEXT("\\H: Display the help\n"));
_tprintf(TEXT("\\D: Database (create if does not exist)\n"));
_tprintf(TEXT("\\A: Archive directories\n"));
exit(0);
}
int _tmain(int argc, TCHAR *argv[])
{
int i;
for (i = 1; i < argc; i++) {
if (_tcscmp(argv[i], TEXT("\\H")) == 0) {
usage();
} else if (_tcscmp(argv[i], TEXT("\\A")) == 0) {
i++;
archive_file_or_directory(argv[i]);
} else if (_tcscmp(argv[i], TEXT("\\D")) == 0) {
i++;
open_db(argv[i]);
} else if (_tcscmp(argv[i], TEXT("\\V")) == 0) {
g_verbose = 1;
} else {
usage();
}
}
if (g_db)
sqlite3_exec(g_db, "COMMIT;", NULL, NULL, NULL);
sqlite3_close(g_db);
return 0;
}