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Strict CRLF parsing as per the http spec. #60

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Strict CRLF parsing as per the http spec. #60

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83 changes: 64 additions & 19 deletions picohttpparser.c
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Original file line number Diff line number Diff line change
Expand Up @@ -520,6 +520,25 @@ static int decode_hex(int ch)
}
}

/*
* chunked-body = *chunk
* last-chunk
* trailer-part
* CRLF
* chunk = chunk-size [ chunk-ext ] CRLF
* chunk-data CRLF
* chunk-size = 1*HEXDIG
* last-chunk = 1*("0") [ chunk-ext ] CRLF
* chunk-data = 1*OCTET ; a sequence of chunk-size octets
* chunk-ext = *( ";" chunk-ext-name [ "=" chunk-ext-val ] )
* chunk-ext-name = token
* chunk-ext-val = token / quoted-string
* trailer-part = *( header-field CRLF )
***
* returns -2 - incomplete
* -1 - error
* >= 0 bytes unprocessed in the buffer
**/
ssize_t phr_decode_chunked(struct phr_chunked_decoder *decoder, char *buf, size_t *_bufsz)
{
size_t dst = 0, src = 0, bufsz = *_bufsz;
Expand Down Expand Up @@ -547,23 +566,32 @@ ssize_t phr_decode_chunked(struct phr_chunked_decoder *decoder, char *buf, size_
++decoder->_hex_count;
}
decoder->_hex_count = 0;
decoder->cr_seen = 0;
decoder->_state = CHUNKED_IN_CHUNK_EXT;
/* fallthru */
case CHUNKED_IN_CHUNK_EXT:
/* RFC 7230 A.2 "Line folding in chunk extensions is disallowed" */
for (;; ++src) {
if (src == bufsz)
goto Exit;
if (buf[src] == '\012')
break;
if (buf[src] == '\015') {
decoder->cr_seen = 1;
} else if (buf[src] == '\012' && decoder->cr_seen) {
break; //CRLF seen, process next line
} else if ((buf[src] != '\012' && decoder->cr_seen) || (buf[src] == '\012' && !decoder->cr_seen)) {
// LF must follow CR
ret = -1;
goto Exit;
} else if (decoder->cr_seen) {
decoder->cr_seen = 0;
}
}
++src;
if (decoder->bytes_left_in_chunk == 0) {
decoder->last_chunk = 1;
if (decoder->consume_trailer) {
decoder->_state = CHUNKED_IN_TRAILERS_LINE_HEAD;
break;
} else {
goto Complete;
}
}
decoder->_state = CHUNKED_IN_CHUNK_DATA;
Expand All @@ -584,41 +612,58 @@ ssize_t phr_decode_chunked(struct phr_chunked_decoder *decoder, char *buf, size_
dst += decoder->bytes_left_in_chunk;
decoder->bytes_left_in_chunk = 0;
decoder->_state = CHUNKED_IN_CHUNK_CRLF;
decoder->cr_seen = 0;
}
/* fallthru */
case CHUNKED_IN_CHUNK_CRLF:
for (;; ++src) {
if (src == bufsz)
goto Exit;
if (buf[src] != '\015')
if ((!decoder->cr_seen && buf[src] != '\015') ||
(decoder->cr_seen && buf[src] != '\012')) {
ret = -1;
goto Exit;
}
if (decoder->cr_seen) { /* CRLF seen in the buffer */
break;
}
if (buf[src] != '\012') {
ret = -1;
goto Exit;
}
decoder->cr_seen = 1;
}
++src;
if (decoder->last_chunk) {
goto Complete;
}
decoder->_state = CHUNKED_IN_CHUNK_SIZE;
break;
case CHUNKED_IN_TRAILERS_LINE_HEAD:
for (;; ++src) {
if (src == bufsz)
goto Exit;
if (buf[src] != '\015')
break;
if (src == bufsz)
goto Exit;
decoder->cr_seen = 0;
if (buf[src] == '\015') {
decoder->_state = CHUNKED_IN_CHUNK_CRLF;
break;
}
if (buf[src++] == '\012')
goto Complete;
++src;
decoder->_state = CHUNKED_IN_TRAILERS_LINE_MIDDLE;
/* fallthru */
/* fallthru */
case CHUNKED_IN_TRAILERS_LINE_MIDDLE:
for (;; ++src) {
if (src == bufsz)
goto Exit;
if (buf[src] == '\012')
if (buf[src] == '\015') {
decoder->cr_seen = 1;
} else if (buf[src] == '\012' && decoder->cr_seen) {
// CRLF seen, process next line
break;
} else if ((buf[src] != '\012' && decoder->cr_seen) || (buf[src] == '\012' && !decoder->cr_seen)) {
// LF must follow CR
ret = -1;
goto Exit;
} else if (decoder->cr_seen) {
decoder->cr_seen = 0;
}
}
++src;
src++;
decoder->_state = CHUNKED_IN_TRAILERS_LINE_HEAD;
break;
default:
Expand Down
2 changes: 2 additions & 0 deletions picohttpparser.h
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Original file line number Diff line number Diff line change
Expand Up @@ -62,6 +62,8 @@ int phr_parse_headers(const char *buf, size_t len, struct phr_header *headers, s
struct phr_chunked_decoder {
size_t bytes_left_in_chunk; /* number of bytes left in current chunk */
char consume_trailer; /* if trailing headers should be consumed */
char last_chunk; /* parsing the last chunk */
char cr_seen; /* if in CHUNK_CRLF state, have we already processed CR */
char _hex_count;
char _state;
};
Expand Down
19 changes: 12 additions & 7 deletions test.c
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Original file line number Diff line number Diff line change
Expand Up @@ -397,19 +397,22 @@ static void test_chunked(void)
size_t i;

for (i = 0; chunked_test_runners[i] != NULL; ++i) {
chunked_test_runners[i](__LINE__, 0, "b\r\nhello world\r\n0\r\n", "hello world", 0);
chunked_test_runners[i](__LINE__, 0, "6\r\nhello \r\n5\r\nworld\r\n0\r\n", "hello world", 0);
chunked_test_runners[i](__LINE__, 0, "6;comment=hi\r\nhello \r\n5\r\nworld\r\n0\r\n", "hello world", 0);
chunked_test_runners[i](__LINE__, 0, "6\r\nhello \r\n5\r\nworld\r\n0\r\na: b\r\nc: d\r\n\r\n", "hello world",
sizeof("a: b\r\nc: d\r\n\r\n") - 1);
chunked_test_runners[i](__LINE__, 0, "b\r\nhello world\r\n0\r\n", "hello world", 0);
chunked_test_runners[i](__LINE__, 0, "b\r\nhello world\r\n0\r\n\r\n", "hello world", 0);
chunked_test_runners[i](__LINE__, 0, "6\r\nhello \r\n5\r\nworld\r\n0\r\n\r\n", "hello world", 0);
chunked_test_runners[i](__LINE__, 0, "6\r\nhello \r\n5\r\nworld\r\n0\r\n\r\n", "hello world", 0);
chunked_test_runners[i](__LINE__, 0, "6;comment=hi\r\nhello \r\n5\r\nworld\r\n0\r\n\r\n", "hello world", 0);
chunked_test_runners[i](__LINE__, 1, "b\r\nhello world\r\n0\r\nTrailer: Content-Type\r\n\r\n", "hello world", 0);
}

note("failures");
test_chunked_failure(__LINE__, "z\r\nabcdefg", -1);
if (sizeof(size_t) == 8) {
test_chunked_failure(__LINE__, "6\r\nhello \r\nffffffffffffffff\r\nabcdefg", -2);
test_chunked_failure(__LINE__, "6\r\nhello \r\nfffffffffffffffff\r\nabcdefg", -1);
test_chunked_failure(__LINE__, "6\r\nhello \r\nfffffffffffffffff\r\nabcdefg", -1);
test_chunked_failure(__LINE__, "6\r\nhello \n0\r\n\r\n", -1);
test_chunked_failure(__LINE__, "6\rhello \n0\r\n\r\n", -1);
test_chunked_failure(__LINE__, "6\nhello \n0\r\n\r\n", -1);
}
}

Expand All @@ -422,8 +425,10 @@ static void test_chunked_consume_trailer(void)
chunked_test_runners[i](__LINE__, 1, "6\r\nhello \r\n5\r\nworld\r\n0\r\n", "hello world", -2);
chunked_test_runners[i](__LINE__, 1, "6;comment=hi\r\nhello \r\n5\r\nworld\r\n0\r\n", "hello world", -2);
chunked_test_runners[i](__LINE__, 1, "b\r\nhello world\r\n0\r\n\r\n", "hello world", 0);
chunked_test_runners[i](__LINE__, 1, "b\nhello world\n0\n\n", "hello world", 0);
chunked_test_runners[i](__LINE__, 1, "b\r\nhello world\r\n0\n", "hello world", -1);
chunked_test_runners[i](__LINE__, 1, "6\r\nhello \r\n5\r\nworld\r\n0\r\na: b\r\nc: d\r\n\r\n", "hello world", 0);
chunked_test_runners[i](__LINE__, 1, "6\r\nhello \r\n5\r\nworld\r\n0\r\na: b\n", "hello world", -1);
chunked_test_runners[i](__LINE__, 1, "6\r\nhello \r\n5\r\nworld\r\n0\r\na: b\r", "hello world", -2);
}
}

Expand Down