*/
#include <stdlib.h>
+#include <string.h>
#include <assert.h>
+#ifdef ZLIB_STANDALONE
+
+/*
+ * This module also makes a handy zlib decoding tool for when
+ * you're picking apart Zip files or PDFs or PNGs. If you compile
+ * it with ZLIB_STANDALONE defined, it builds on its own and
+ * becomes a command-line utility.
+ *
+ * Therefore, here I provide a self-contained implementation of the
+ * macros required from the rest of the PuTTY sources.
+ */
+#define snew(type) ( (type *) malloc(sizeof(type)) )
+#define snewn(n, type) ( (type *) malloc((n) * sizeof(type)) )
+#define sresize(x, n, type) ( (type *) realloc((x), (n) * sizeof(type)) )
+#define sfree(x) ( free((x)) )
+
+#else
#include "ssh.h"
+#endif
#ifndef FALSE
#define FALSE 0
unsigned char *data, int len, int compress)
{
struct LZ77InternalContext *st = ctx->ictx;
- int i, hash, distance, off, nmatch, matchlen, advance;
+ int i, distance, off, nmatch, matchlen, advance;
struct Match defermatch, matches[MAXMATCH];
int deferchr;
+ assert(st->npending <= HASHCHARS);
+
/*
* Add any pending characters from last time to the window. (We
* might not be able to.)
+ *
+ * This leaves st->pending empty in the usual case (when len >=
+ * HASHCHARS); otherwise it leaves st->pending empty enough that
+ * adding all the remaining 'len' characters will not push it past
+ * HASHCHARS in size.
*/
for (i = 0; i < st->npending; i++) {
unsigned char foo[HASHCHARS];
}
st->npending -= i;
+ defermatch.distance = 0; /* appease compiler */
defermatch.len = 0;
deferchr = '\0';
while (len > 0) {
/*
* Hash the next few characters.
*/
- hash = lz77_hash(data);
+ int hash = lz77_hash(data);
/*
* Look the hash up in the corresponding hash chain and see
}
} else {
nmatch = 0;
- hash = INVALID;
}
if (nmatch > 0) {
if (len >= HASHCHARS) {
lz77_advance(st, *data, lz77_hash(data));
} else {
+ assert(st->npending < HASHCHARS);
st->pending[st->npending++] = *data;
}
data++;
{
struct LZ77Context *ectx = (struct LZ77Context *)handle;
sfree(ectx->userdata);
+ sfree(ectx->ictx);
+ sfree(ectx);
}
/*
/*
* Start a Deflate (RFC1951) uncompressed block. We
- * transmit a zero bit (BFINAL=0), followed by a zero
- * bit and a one bit (BTYPE=00). Of course these are in
- * the wrong order (00 0).
+ * transmit a zero bit (BFINAL=0), followed by two more
+ * zero bits (BTYPE=00). Of course these are in the
+ * wrong order (00 0), not that it matters.
*/
outbits(out, 0, 3);
void zlib_decompress_cleanup(void *handle)
{
struct zlib_decompress_ctx *dctx = (struct zlib_decompress_ctx *)handle;
-
+
if (dctx->currlentable && dctx->currlentable != dctx->staticlentable)
zlib_freetable(&dctx->currlentable);
if (dctx->currdisttable && dctx->currdisttable != dctx->staticdisttable)
zlib_freetable(&dctx->currdisttable);
if (dctx->lenlentable)
zlib_freetable(&dctx->lenlentable);
+ zlib_freetable(&dctx->staticlentable);
+ zlib_freetable(&dctx->staticdisttable);
sfree(dctx);
}
*nbitsp = nbits;
return ent->code;
}
+
+ if (!tab) {
+ /*
+ * There was a missing entry in the table, presumably
+ * due to an invalid Huffman table description, and the
+ * subsequent data has attempted to use the missing
+ * entry. Return a decoding failure.
+ */
+ return -2;
+ }
}
}
{
struct zlib_decompress_ctx *dctx = (struct zlib_decompress_ctx *)handle;
const coderecord *rec;
- int code, blktype, rep, dist, nlen;
+ int code, blktype, rep, dist, nlen, header;
static const unsigned char lenlenmap[] = {
16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
};
- dctx->outblk = NULL;
- dctx->outsize = dctx->outlen = 0;
+ dctx->outblk = snewn(256, unsigned char);
+ dctx->outsize = 256;
+ dctx->outlen = 0;
while (len > 0 || dctx->nbits > 0) {
while (dctx->nbits < 24 && len > 0) {
}
switch (dctx->state) {
case START:
- /* Expect 16-bit zlib header, which we'll dishonourably ignore. */
+ /* Expect 16-bit zlib header. */
if (dctx->nbits < 16)
goto finished; /* done all we can */
- EATBITS(16);
+
+ /*
+ * The header is stored as a big-endian 16-bit integer,
+ * in contrast to the general little-endian policy in
+ * the rest of the format :-(
+ */
+ header = (((dctx->bits & 0xFF00) >> 8) |
+ ((dctx->bits & 0x00FF) << 8));
+ EATBITS(16);
+
+ /*
+ * Check the header:
+ *
+ * - bits 8-11 should be 1000 (Deflate/RFC1951)
+ * - bits 12-15 should be at most 0111 (window size)
+ * - bit 5 should be zero (no dictionary present)
+ * - we don't care about bits 6-7 (compression rate)
+ * - bits 0-4 should be set up to make the whole thing
+ * a multiple of 31 (checksum).
+ */
+ if ((header & 0x0F00) != 0x0800 ||
+ (header & 0xF000) > 0x7000 ||
+ (header & 0x0020) != 0x0000 ||
+ (header % 31) != 0)
+ goto decode_error;
+
dctx->state = OUTSIDEBLK;
break;
case OUTSIDEBLK:
zlib_huflookup(&dctx->bits, &dctx->nbits, dctx->lenlentable);
if (code == -1)
goto finished;
+ if (code == -2)
+ goto decode_error;
if (code < 16)
dctx->lengths[dctx->lenptr++] = code;
else {
zlib_huflookup(&dctx->bits, &dctx->nbits, dctx->currlentable);
if (code == -1)
goto finished;
+ if (code == -2)
+ goto decode_error;
if (code < 256)
zlib_emit_char(dctx, code);
else if (code == 256) {
dctx->currdisttable);
if (code == -1)
goto finished;
+ if (code == -2)
+ goto decode_error;
+ if (code >= 30) /* dist symbols 30 and 31 are invalid */
+ goto decode_error;
dctx->state = GOTDISTSYM;
dctx->sym = code;
break;
goto finished;
nlen = dctx->bits & 0xFFFF;
EATBITS(16);
+ if (dctx->uncomplen != (nlen ^ 0xFFFF))
+ goto decode_error;
if (dctx->uncomplen == 0)
dctx->state = OUTSIDEBLK; /* block is empty */
else
finished:
*outblock = dctx->outblk;
*outlen = dctx->outlen;
-
return 1;
+
+ decode_error:
+ sfree(dctx->outblk);
+ *outblock = dctx->outblk = NULL;
+ *outlen = 0;
+ return 0;
+}
+
+#ifdef ZLIB_STANDALONE
+
+#include <stdio.h>
+#include <string.h>
+
+int main(int argc, char **argv)
+{
+ unsigned char buf[16], *outbuf;
+ int ret, outlen;
+ void *handle;
+ int noheader = FALSE, opts = TRUE;
+ char *filename = NULL;
+ FILE *fp;
+
+ while (--argc) {
+ char *p = *++argv;
+
+ if (p[0] == '-' && opts) {
+ if (!strcmp(p, "-d"))
+ noheader = TRUE;
+ else if (!strcmp(p, "--"))
+ opts = FALSE; /* next thing is filename */
+ else {
+ fprintf(stderr, "unknown command line option '%s'\n", p);
+ return 1;
+ }
+ } else if (!filename) {
+ filename = p;
+ } else {
+ fprintf(stderr, "can only handle one filename\n");
+ return 1;
+ }
+ }
+
+ handle = zlib_decompress_init();
+
+ if (noheader) {
+ /*
+ * Provide missing zlib header if -d was specified.
+ */
+ zlib_decompress_block(handle, "\x78\x9C", 2, &outbuf, &outlen);
+ assert(outlen == 0);
+ }
+
+ if (filename)
+ fp = fopen(filename, "rb");
+ else
+ fp = stdin;
+
+ if (!fp) {
+ assert(filename);
+ fprintf(stderr, "unable to open '%s'\n", filename);
+ return 1;
+ }
+
+ while (1) {
+ ret = fread(buf, 1, sizeof(buf), fp);
+ if (ret <= 0)
+ break;
+ zlib_decompress_block(handle, buf, ret, &outbuf, &outlen);
+ if (outbuf) {
+ if (outlen)
+ fwrite(outbuf, 1, outlen, stdout);
+ sfree(outbuf);
+ } else {
+ fprintf(stderr, "decoding error\n");
+ fclose(fp);
+ return 1;
+ }
+ }
+
+ zlib_decompress_cleanup(handle);
+
+ if (filename)
+ fclose(fp);
+
+ return 0;
}
+#else
+
const struct ssh_compress ssh_zlib = {
"zlib",
+ "zlib@openssh.com", /* delayed version */
zlib_compress_init,
zlib_compress_cleanup,
zlib_compress_block,
zlib_disable_compression,
"zlib (RFC1950)"
};
+
+#endif