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#include "encpipe_p.h"
static struct option getopt_long_options[] = {
{ "help", 0, NULL, 'h' }, { "decrypt", 0, NULL, 'd' }, { "encrypt", 0, NULL, 'e' },
{ "in", 1, NULL, 'i' }, { "out", 1, NULL, 'o' }, { "p", 1, NULL, 'p' },
{ NULL, 0, NULL, 0 }
};
static const char *getopt_options = "hdei:o:p:";
static void
usage(void)
{
puts(
"Usage:\n\n"
"Encrypt: encpipe -e -p <password> [-i <inputfile>] [-o <outputfile>]\n"
"Decrypt: encpipe -d -p <password> [-i <inputfile>] [-o <outputfile>]");
exit(0);
}
static void
options_parse(Context *ctx, int argc, char *argv[])
{
int opt_flag;
int option_index = 0;
ctx->encrypt = -1;
ctx->in = NULL;
ctx->out = NULL;
ctx->password = NULL;
optind = 0;
#ifdef _OPTRESET
optreset = 1;
#endif
while ((opt_flag = getopt_long(argc, argv, getopt_options, getopt_long_options,
&option_index)) != -1) {
switch (opt_flag) {
case 'd':
ctx->encrypt = 0;
break;
case 'e':
ctx->encrypt = 1;
break;
case 'i':
ctx->in = optarg;
break;
case 'o':
ctx->out = optarg;
break;
case 'p':
ctx->password = optarg;
break;
default:
usage();
}
}
if (ctx->password == NULL || ctx->encrypt == -1) {
usage();
}
}
static int
file_open(const char *file, int create)
{
int fd;
if (file == NULL || (file[0] == '-' && file[1] == 0)) {
return create ? STDOUT_FILENO : STDIN_FILENO;
}
fd = create ? open(file, O_CREAT | O_WRONLY | O_TRUNC, 0644) : open(file, O_RDONLY);
if (fd == -1) {
die(1, "Unable to access [%s]", file);
}
return fd;
}
static void
derive_key(Context *ctx)
{
static uint8_t master_key[hydro_pwhash_MASTERKEYBYTES] = { 0 };
size_t password_len = strlen(ctx->password);
if (hydro_pwhash_deterministic(ctx->key, sizeof ctx->key, ctx->password, password_len,
HYDRO_CONTEXT, master_key, PWHASH_OPSLIMIT, PWHASH_MEMLIMIT,
PWHASH_THREADS) != 0) {
die(0, "Password hashing failed");
}
hydro_memzero(ctx->password, password_len);
}
static int
stream_encrypt(Context *ctx)
{
unsigned char *const chunk_size_p = ctx->buf;
unsigned char *const chunk = chunk_size_p + 4;
uint64_t chunk_id;
ssize_t max_chunk_size;
ssize_t chunk_size;
assert(ctx->sizeof_buf >= 4 + hydro_secretbox_HEADERBYTES);
max_chunk_size = ctx->sizeof_buf - 4 - hydro_secretbox_HEADERBYTES;
assert(max_chunk_size <= 0x7fffffff);
chunk_id = 0;
while ((chunk_size = safe_read_partial(ctx->fd_in, chunk, max_chunk_size)) >= 0) {
STORE32_LE(chunk_size_p, (uint32_t) chunk_size);
if (hydro_secretbox_encrypt(chunk, chunk, chunk_size, chunk_id, HYDRO_CONTEXT, ctx->key) !=
0) {
die(0, "Encryption error");
}
if (safe_write(ctx->fd_out, chunk_size_p,
4 + hydro_secretbox_HEADERBYTES + (size_t) chunk_size, -1) < 0) {
die(1, "write()");
}
if (chunk_size == 0) {
break;
}
chunk_id++;
}
if (chunk_size < 0) {
die(1, "read()");
}
return 0;
}
static int
stream_decrypt(Context *ctx)
{
unsigned char *const chunk_size_p = ctx->buf;
unsigned char *const chunk = chunk_size_p + 4;
uint64_t chunk_id;
ssize_t readnb;
ssize_t max_chunk_size;
ssize_t chunk_size;
assert(ctx->sizeof_buf >= 4 + hydro_secretbox_HEADERBYTES);
max_chunk_size = ctx->sizeof_buf - 4 - hydro_secretbox_HEADERBYTES;
assert(max_chunk_size <= 0x7fffffff);
chunk_id = 0;
while ((readnb = safe_read(ctx->fd_in, chunk_size_p, 4)) == 4) {
chunk_size = LOAD32_LE(chunk_size_p);
if (chunk_size > max_chunk_size) {
die(0, "Chunk size too large ([%zd] > [%zd])", chunk_size, max_chunk_size);
}
if (safe_read(ctx->fd_in, chunk, (size_t) chunk_size + hydro_secretbox_HEADERBYTES) !=
chunk_size + hydro_secretbox_HEADERBYTES) {
die(0, "Chunk too short ([%zd] bytes expected)", chunk_size);
}
if (hydro_secretbox_decrypt(chunk, chunk, chunk_size + hydro_secretbox_HEADERBYTES,
chunk_id, HYDRO_CONTEXT, ctx->key) != 0) {
fprintf(stderr, "Unable to decrypt chunk #%" PRIu64 " - ", chunk_id);
if (chunk_id == 0) {
die(0, "Wrong password or key?");
} else {
die(0, "Corrupted or incomplete file?");
}
}
if (chunk_size == 0) {
break;
}
if (safe_write(ctx->fd_out, chunk, chunk_size, -1) < 0) {
die(1, "write()");
}
chunk_id++;
}
if (readnb < 0) {
die(1, "read()");
}
if (chunk_size != 0) {
die(0, "Premature end of file");
}
return 0;
}
int
main(int argc, char *argv[])
{
Context ctx;
if (hydro_init() < 0) {
die(1, "Unable to initialize the crypto library");
}
memset(&ctx, 0, sizeof ctx);
options_parse(&ctx, argc, argv);
derive_key(&ctx);
ctx.sizeof_buf = DEFAULT_BUFFER_SIZE;
if (ctx.sizeof_buf < MIN_BUFFER_SIZE) {
ctx.sizeof_buf = MIN_BUFFER_SIZE;
} else if (ctx.sizeof_buf > MAX_BUFFER_SIZE) {
ctx.sizeof_buf = MAX_BUFFER_SIZE;
}
if ((ctx.buf = malloc(ctx.sizeof_buf)) == NULL) {
die(1, "malloc()");
}
assert(sizeof HYDRO_CONTEXT == hydro_secretbox_CONTEXTBYTES);
ctx.fd_in = file_open(ctx.in, 0);
ctx.fd_out = file_open(ctx.out, 1);
if (ctx.encrypt) {
stream_encrypt(&ctx);
} else {
stream_decrypt(&ctx);
}
free(ctx.buf);
close(ctx.fd_out);
close(ctx.fd_in);
hydro_memzero(&ctx, sizeof ctx);
return 0;
}
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