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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 09:51:24 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 09:51:24 +0000
commitf7548d6d28c313cf80e6f3ef89aed16a19815df1 (patch)
treea3f6f2a3f247293bee59ecd28e8cd8ceb6ca064a /src/lib-http/http-header-parser.c
parentInitial commit. (diff)
downloaddovecot-upstream.tar.xz
dovecot-upstream.zip
Adding upstream version 1:2.3.19.1+dfsg1.upstream/1%2.3.19.1+dfsg1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--src/lib-http/http-header-parser.c367
1 files changed, 367 insertions, 0 deletions
diff --git a/src/lib-http/http-header-parser.c b/src/lib-http/http-header-parser.c
new file mode 100644
index 0000000..29de688
--- /dev/null
+++ b/src/lib-http/http-header-parser.c
@@ -0,0 +1,367 @@
+/* Copyright (c) 2013-2018 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "buffer.h"
+#include "istream.h"
+#include "str.h"
+#include "str-sanitize.h"
+#include "http-parser.h"
+#include "http-header.h"
+
+#include "http-header-parser.h"
+
+enum http_header_parse_state {
+ HTTP_HEADER_PARSE_STATE_INIT = 0,
+ HTTP_HEADER_PARSE_STATE_NAME,
+ HTTP_HEADER_PARSE_STATE_COLON,
+ HTTP_HEADER_PARSE_STATE_OWS,
+ HTTP_HEADER_PARSE_STATE_CONTENT,
+ HTTP_HEADER_PARSE_STATE_CR,
+ HTTP_HEADER_PARSE_STATE_LF,
+ HTTP_HEADER_PARSE_STATE_NEW_LINE,
+ HTTP_HEADER_PARSE_STATE_EOH
+};
+
+struct http_header_parser {
+ struct istream *input;
+
+ struct http_header_limits limits;
+ enum http_header_parse_flags flags;
+
+ uoff_t size, field_size;
+ unsigned int field_count;
+
+ const unsigned char *begin, *cur, *end;
+ const char *error;
+
+ string_t *name;
+ buffer_t *value_buf;
+
+ enum http_header_parse_state state;
+};
+
+struct http_header_parser *
+http_header_parser_init(struct istream *input,
+ const struct http_header_limits *limits,
+ enum http_header_parse_flags flags)
+{
+ struct http_header_parser *parser;
+
+ parser = i_new(struct http_header_parser, 1);
+ parser->input = input;
+
+ if (limits != NULL)
+ parser->limits = *limits;
+
+ if (parser->limits.max_size == 0)
+ parser->limits.max_size = UOFF_T_MAX;
+ if (parser->limits.max_field_size == 0)
+ parser->limits.max_field_size = UOFF_T_MAX;
+ if (parser->limits.max_fields == 0)
+ parser->limits.max_fields = (unsigned int)-1;
+
+ parser->flags = flags;
+
+ parser->name = str_new(default_pool, 128);
+ parser->value_buf = buffer_create_dynamic(default_pool, 4096);
+
+ return parser;
+}
+
+void http_header_parser_deinit(struct http_header_parser **_parser)
+{
+ struct http_header_parser *parser = *_parser;
+
+ *_parser = NULL;
+
+ //i_stream_skip(ctx->input, ctx->skip);
+ buffer_free(&parser->value_buf);
+ str_free(&parser->name);
+ i_free(parser);
+}
+
+void http_header_parser_reset(struct http_header_parser *parser)
+{
+ parser->state = HTTP_HEADER_PARSE_STATE_INIT;
+ parser->size = 0;
+ parser->field_size = 0;
+ parser->field_count = 0;
+}
+
+static int http_header_parse_name(struct http_header_parser *parser)
+{
+ const unsigned char *first = parser->cur;
+
+ /* field-name = token
+ token = 1*tchar
+ */
+ while (parser->cur < parser->end && http_char_is_token(*parser->cur))
+ parser->cur++;
+
+ str_append_data(parser->name, first, parser->cur-first);
+
+ if (parser->cur == parser->end)
+ return 0;
+ if (str_len(parser->name) == 0) {
+ parser->error = "Empty header field name";
+ return -1;
+ }
+ return 1;
+}
+
+static int http_header_parse_ows(struct http_header_parser *parser)
+{
+ /* OWS = *( SP / HTAB )
+ ; "optional" whitespace
+ */
+ while (parser->cur < parser->end &&
+ (*parser->cur == ' ' || *parser->cur == '\t'))
+ parser->cur++;
+ return (parser->cur == parser->end ? 0 : 1);
+}
+
+static int http_header_parse_content(struct http_header_parser *parser)
+{
+ const unsigned char *first;
+
+ /* field-content = field-vchar [ 1*( SP / HTAB ) field-vchar ]
+ field-vchar = VCHAR / obs-text
+ */
+ do {
+ first = parser->cur;
+ while (parser->cur < parser->end && http_char_is_text(*parser->cur)) {
+ parser->cur++;
+ }
+ buffer_append(parser->value_buf, first, parser->cur-first);
+
+ if ((parser->flags & HTTP_HEADER_PARSE_FLAG_STRICT) != 0)
+ break;
+
+ /* We'll be lenient here to accommodate for some bad servers. We just
+ drop offending characters */
+ while (parser->cur < parser->end && !http_char_is_text(*parser->cur) &&
+ (*parser->cur != '\r' && *parser->cur != '\n'))
+ parser->cur++;
+ } while (parser->cur < parser->end &&
+ (*parser->cur != '\r' && *parser->cur != '\n'));
+
+ if (parser->cur == parser->end)
+ return 0;
+ return 1;
+}
+
+static inline const char *_chr_sanitize(unsigned char c)
+{
+ if (c >= 0x20 && c < 0x7F)
+ return t_strdup_printf("'%c'", c);
+ return t_strdup_printf("0x%02x", c);
+}
+
+static int http_header_parse(struct http_header_parser *parser)
+{
+ int ret;
+
+ /* RFC 7230, Section 3.2: Header Fields
+
+ 'header' = *( header-field CRLF ) CRLF
+ ; Actually part of HTTP-message syntax
+
+ header-field = field-name ":" OWS field-value OWS
+ field-name = token
+ field-value = *( field-content / obs-fold )
+ field-content = field-vchar [ 1*( SP / HTAB ) field-vchar ]
+ field-vchar = VCHAR / obs-text
+ obs-fold = CRLF 1*( SP / HTAB )
+ ; obsolete line folding
+ ; see Section 3.2.4
+ */
+
+ for (;;) {
+ switch (parser->state) {
+ case HTTP_HEADER_PARSE_STATE_INIT:
+ buffer_set_used_size(parser->value_buf, 0);
+ str_truncate(parser->name, 0);
+ if (*parser->cur == '\r') {
+ /* last CRLF */
+ parser->cur++;
+ parser->state = HTTP_HEADER_PARSE_STATE_EOH;
+ if (parser->cur == parser->end)
+ return 0;
+ break;
+ } else if (*parser->cur == '\n') {
+ /* last LF */
+ parser->state = HTTP_HEADER_PARSE_STATE_EOH;
+ break;
+ }
+ /* next line */
+ parser->state = HTTP_HEADER_PARSE_STATE_NAME;
+ /* fall through */
+ case HTTP_HEADER_PARSE_STATE_NAME:
+ if ((ret=http_header_parse_name(parser)) <= 0)
+ return ret;
+ parser->state = HTTP_HEADER_PARSE_STATE_COLON;
+ /* fall through */
+ case HTTP_HEADER_PARSE_STATE_COLON:
+ if (*parser->cur != ':') {
+ parser->error = t_strdup_printf
+ ("Expected ':' after header field name '%s', but found %s",
+ str_sanitize(str_c(parser->name),64),
+ _chr_sanitize(*parser->cur));
+ return -1;
+ }
+ parser->cur++;
+ if (str_len(parser->name) == 0) {
+ parser->error = "Empty header field name";
+ return -1;
+ }
+ if (++parser->field_count > parser->limits.max_fields) {
+ parser->error = "Excessive number of header fields";
+ return -1;
+ }
+ parser->state = HTTP_HEADER_PARSE_STATE_OWS;
+ /* fall through */
+ case HTTP_HEADER_PARSE_STATE_OWS:
+ if ((ret=http_header_parse_ows(parser)) <= 0)
+ return ret;
+ parser->state = HTTP_HEADER_PARSE_STATE_CONTENT;
+ /* fall through */
+ case HTTP_HEADER_PARSE_STATE_CONTENT:
+ if ((ret=http_header_parse_content(parser)) <= 0)
+ return ret;
+ parser->state = HTTP_HEADER_PARSE_STATE_CR;
+ /* fall through */
+ case HTTP_HEADER_PARSE_STATE_CR:
+ if (*parser->cur == '\r') {
+ parser->cur++;
+ } else if (*parser->cur != '\n') {
+ parser->error = t_strdup_printf
+ ("Invalid character %s in content of header field '%s'",
+ _chr_sanitize(*parser->cur),
+ str_sanitize(str_c(parser->name),64));
+ return -1;
+ }
+ parser->state = HTTP_HEADER_PARSE_STATE_LF;
+ if (parser->cur == parser->end)
+ return 0;
+ /* fall through */
+ case HTTP_HEADER_PARSE_STATE_LF:
+ if (*parser->cur != '\n') {
+ parser->error = t_strdup_printf
+ ("Expected LF after CR at end of header field '%s', but found %s",
+ str_sanitize(str_c(parser->name),64),
+ _chr_sanitize(*parser->cur));
+ return -1;
+ }
+ parser->cur++;
+ parser->state = HTTP_HEADER_PARSE_STATE_NEW_LINE;
+ if (parser->cur == parser->end)
+ return 0;
+ /* fall through */
+ case HTTP_HEADER_PARSE_STATE_NEW_LINE:
+ if (*parser->cur == ' ' || *parser->cur == '\t') {
+ /* obs-fold */
+ buffer_append_c(parser->value_buf, ' ');
+ parser->state = HTTP_HEADER_PARSE_STATE_OWS;
+ break;
+ }
+ /* next header line */
+ parser->state = HTTP_HEADER_PARSE_STATE_INIT;
+ return 1;
+ case HTTP_HEADER_PARSE_STATE_EOH:
+ if (*parser->cur != '\n') {
+ parser->error = t_strdup_printf
+ ("Encountered stray CR at beginning of header line, followed by %s",
+ _chr_sanitize(*parser->cur));
+ return -1;
+ }
+ /* header fully parsed */
+ parser->cur++;
+ return 1;
+
+ default:
+ i_unreached();
+ }
+ }
+
+ i_unreached();
+ return -1;
+}
+
+int http_header_parse_next_field(struct http_header_parser *parser,
+ const char **name_r, const unsigned char **data_r, size_t *size_r,
+ const char **error_r)
+{
+ const uoff_t max_size = parser->limits.max_size;
+ const uoff_t max_field_size = parser->limits.max_field_size;
+ const unsigned char *data;
+ size_t size;
+ int ret;
+
+ *error_r = NULL;
+
+ while ((ret=i_stream_read_more(parser->input, &parser->begin, &size)) > 0) {
+
+ /* check header size limits */
+ if (parser->size >= max_size) {
+ *error_r = "Excessive header size";
+ return -1;
+ }
+ if (parser->field_size > max_field_size) {
+ *error_r = "Excessive header field size";
+ return -1;
+ }
+
+ /* don't parse beyond header size limits */
+ if (size > (max_size - parser->size))
+ size = max_size - parser->size;
+ if (size > (max_field_size - parser->field_size)) {
+ size = max_field_size - parser->field_size;
+ size = (size == 0 ? 1 : size); /* need to parse one more byte */
+ }
+
+ parser->cur = parser->begin;
+ parser->end = parser->cur + size;
+
+ if ((ret=http_header_parse(parser)) < 0) {
+ *error_r = parser->error;
+ return -1;
+ }
+
+ i_stream_skip(parser->input, parser->cur - parser->begin);
+ parser->size += parser->cur - parser->begin;
+ parser->field_size += parser->cur - parser->begin;
+
+ if (ret == 1) {
+ parser->field_size = 0;
+
+ if (parser->state != HTTP_HEADER_PARSE_STATE_EOH) {
+ data = buffer_get_data(parser->value_buf, &size);
+
+ /* trim trailing OWS */
+ while (size > 0 &&
+ (data[size-1] == ' ' || data[size-1] == '\t'))
+ size--;
+
+ *name_r = str_c(parser->name);
+ *data_r = data;
+ *size_r = size;
+ parser->state = HTTP_HEADER_PARSE_STATE_INIT;
+ } else {
+ *name_r = NULL;
+ *data_r = NULL;
+ }
+ return 1;
+ }
+ }
+
+ i_assert(ret != -2);
+ if (ret < 0) {
+ i_assert(parser->input->eof);
+ if (parser->input->stream_errno == 0)
+ *error_r = "Premature end of input";
+ else
+ *error_r = t_strdup_printf("Stream error: %s",
+ i_stream_get_error(parser->input));
+ }
+ return ret;
+}