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phar: use crc32 bulk method instead. #6099

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Merged
merged 2 commits into from
Jun 19, 2021
Merged

phar: use crc32 bulk method instead. #6099

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685bfd5
phar: use crc32 bulk method instead.
frankdjx Sep 9, 2020
4fe5b96
crc32_stream_bulk_update: return FAILURE if stream reading fail.
frankdjx Jun 17, 2021
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15 changes: 5 additions & 10 deletions ext/phar/phar.c
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Original file line number Diff line number Diff line change
Expand Up @@ -2374,7 +2374,7 @@ int phar_open_executed_filename(char *alias, size_t alias_len, char **error) /*
int phar_postprocess_file(phar_entry_data *idata, uint32_t crc32, char **error, int process_zip) /* {{{ */
{
uint32_t crc = ~0;
int len = idata->internal_file->uncompressed_filesize;
int len = idata->internal_file->uncompressed_filesize, ret;
php_stream *fp = idata->fp;
phar_entry_info *entry = idata->internal_file;

Expand Down Expand Up @@ -2439,13 +2439,11 @@ int phar_postprocess_file(phar_entry_data *idata, uint32_t crc32, char **error,

php_stream_seek(fp, idata->zero, SEEK_SET);

while (len--) {
CRC32(crc, php_stream_getc(fp));
}
ret = crc32_stream_bulk_update(&crc, fp, len);

php_stream_seek(fp, idata->zero, SEEK_SET);

if (~crc == crc32) {
if (SUCCESS == ret && ~crc == crc32) {
entry->is_crc_checked = 1;
return SUCCESS;
} else {
Expand Down Expand Up @@ -2539,7 +2537,7 @@ int phar_flush(phar_archive_data *phar, char *user_stub, zend_long len, int conv
zend_off_t manifest_ftell;
zend_long offset;
size_t wrote;
uint32_t manifest_len, mytime, loc, new_manifest_count;
uint32_t manifest_len, mytime, new_manifest_count;
uint32_t newcrc32;
php_stream *file, *oldfile, *newfile, *stubfile;
php_stream_filter *filter;
Expand Down Expand Up @@ -2796,10 +2794,7 @@ int phar_flush(phar_archive_data *phar, char *user_stub, zend_long len, int conv
return EOF;
}
newcrc32 = ~0;
mytime = entry->uncompressed_filesize;
for (loc = 0;loc < mytime; ++loc) {
CRC32(newcrc32, php_stream_getc(file));
}
crc32_stream_bulk_update(&newcrc32, file, entry->uncompressed_filesize);
entry->crc32 = ~newcrc32;
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@frankdjx frankdjx Jun 17, 2021 •
edited
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Seems we don't need check the return as it just generate a crc value here.

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This might be another plus to return the processed length and compare with uncompressed_filesize for a better security. Otherwise might make sense to (void) to silence possible static analyzer warnings.

thanks.

entry->is_crc_checked = 1;
if (!(entry->flags & PHAR_ENT_COMPRESSION_MASK)) {
Expand Down
5 changes: 1 addition & 4 deletions ext/phar/zip.c
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Expand Up @@ -882,7 +882,6 @@ static int phar_zip_changed_apply_int(phar_entry_info *entry, void *arg) /* {{{

/* do extra field for perms later */
if (entry->is_modified) {
uint32_t loc;
php_stream_filter *filter;
php_stream *efp;

Expand Down Expand Up @@ -915,9 +914,7 @@ static int phar_zip_changed_apply_int(phar_entry_info *entry, void *arg) /* {{{
efp = phar_get_efp(entry, 0);
newcrc32 = ~0;

for (loc = 0;loc < entry->uncompressed_filesize; ++loc) {
CRC32(newcrc32, php_stream_getc(efp));
}
crc32_stream_bulk_update(&newcrc32, efp, entry->uncompressed_filesize);
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Same here.


entry->crc32 = ~newcrc32;
PHAR_SET_32(central.uncompsize, entry->uncompressed_filesize);
Expand Down
58 changes: 44 additions & 14 deletions ext/standard/crc32.c
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Expand Up @@ -89,24 +89,12 @@ static uint32_t crc32_aarch64(uint32_t crc, char *p, size_t nr) {
# endif
#endif

/* {{{ Calculate the crc32 polynomial of a string */
PHP_FUNCTION(crc32)
uint32_t crc32_bulk_update(uint32_t crc, const char *p, size_t nr)
{
char *p;
size_t nr;
uint32_t crcinit = 0;
uint32_t crc;

ZEND_PARSE_PARAMETERS_START(1, 1)
Z_PARAM_STRING(p, nr)
ZEND_PARSE_PARAMETERS_END();

crc = crcinit^0xFFFFFFFF;

#if HAVE_AARCH64_CRC32
if (has_crc32_insn()) {
crc = crc32_aarch64(crc, p, nr);
RETURN_LONG(crc^0xFFFFFFFF);
return crc;
}
#endif

Expand All @@ -116,9 +104,51 @@ PHP_FUNCTION(crc32)
p += nr_simd;
#endif

/* The trailing part */
for (; nr--; ++p) {
crc = ((crc >> 8) & 0x00FFFFFF) ^ crc32tab[(crc ^ (*p)) & 0xFF ];
}

return crc;
}

int crc32_stream_bulk_update(uint32_t *crc, php_stream *fp, size_t nr)
{
size_t handled = 0, n;
char buf[1024];

while (handled < nr) {
n = nr - handled;
n = (n < sizeof(buf)) ? n : sizeof(buf); /* tweak to buf size */

n = php_stream_read(fp, buf, n);
if (n > 0) {
*crc = crc32_bulk_update(*crc, buf, n);
handled += n;
} else { /* EOF */
return FAILURE;
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NIT EOF might be not directly an error, since it loops and EOL might be delivered not in the first iteration. Probably ok if it's only about local files, but stream can be anything (also remote). Perhaps it's better to return handled or EOF. Anyway this does the job and we don't export.

Thanks!

}
}

return SUCCESS;
}

/* {{{ Calculate the crc32 polynomial of a string */
PHP_FUNCTION(crc32)
{
char *p;
size_t nr;
uint32_t crcinit = 0;
uint32_t crc;

ZEND_PARSE_PARAMETERS_START(1, 1)
Z_PARAM_STRING(p, nr)
ZEND_PARSE_PARAMETERS_END();

crc = crcinit^0xFFFFFFFF;

crc = crc32_bulk_update(crc, p, nr);

RETURN_LONG(crc^0xFFFFFFFF);
}
/* }}} */
5 changes: 5 additions & 0 deletions ext/standard/crc32.h
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Expand Up @@ -23,6 +23,11 @@

#define CRC32(crc, ch) (crc = (crc >> 8) ^ crc32tab[(crc ^ (ch)) & 0xff])

uint32_t crc32_bulk_update(uint32_t crc, const char *p, size_t nr);

/* Return FAILURE if stream reading fail */
int crc32_stream_bulk_update(uint32_t *crc, php_stream *fp, size_t nr);

/* generated using the AUTODIN II polynomial
* x^32 + x^26 + x^23 + x^22 + x^16 +
* x^12 + x^11 + x^10 + x^8 + x^7 + x^5 + x^4 + x^2 + x^1 + 1
Expand Down