lib-mail: Limit header length to 1000 bytes

diff --git a/src/lib-mail/message-header-parser.c b/src/lib-mail/message-header-parser.c
index 80210d2269522be98f78dc4d898ac4095f89eb26..c5026f1bb72d63edf07927c66f7ad58be2ae551c 100644 (file)
--- a/src/lib-mail/message-header-parser.c
+++ b/src/lib-mail/message-header-parser.c
@@ -9,6 +9,9 @@
 #include "message-size.h"
 #include "message-header-parser.h"
 
+/* RFC 5322 2.1.1 and 2.2 */
+#define MESSAGE_HEADER_NAME_MAX_LEN 1000
+
 struct message_header_parser_ctx {
        struct message_header_line line;
 
@@ -309,21 +312,34 @@ int message_parse_header_next(struct message_header_parser_ctx *ctx,
                while (colon_pos > 0 && IS_LWSP(msg[colon_pos-1]))
                        colon_pos--;
 
-               str_truncate(ctx->name, 0);
-               /* use buffer_append() so the name won't be truncated if there
-                  are NULs. */
-               buffer_append(ctx->name, msg, colon_pos);
-               str_append_c(ctx->name, '\0');
-
-               /* keep middle stored also in ctx->name so it's available
-                  with use_full_value */
-               line->middle = msg + colon_pos;
-               line->middle_len = (size_t)(line->value - line->middle);
-               str_append_data(ctx->name, line->middle, line->middle_len);
-
-               line->name = str_c(ctx->name);
-               line->name_len = colon_pos;
-               line->middle = str_data(ctx->name) + line->name_len + 1;
+               /* Treat overlong header names as if the full header line was
+                  a value. Callers can usually handle large values better than
+                  large names. */
+               if (colon_pos > MESSAGE_HEADER_NAME_MAX_LEN) {
+                       line->name = "";
+                       line->name_len = 0;
+                       line->middle = uchar_empty_ptr;
+                       line->middle_len = 0;
+                       line->value = msg;
+                       line->value_len = size;
+                       line->full_value_offset = line->name_offset;
+               } else {
+                       str_truncate(ctx->name, 0);
+                       /* use buffer_append() so the name won't be truncated if there
+                          are NULs. */
+                       buffer_append(ctx->name, msg, colon_pos);
+                       str_append_c(ctx->name, '\0');
+
+                       /* keep middle stored also in ctx->name so it's available
+                          with use_full_value */
+                       line->middle = msg + colon_pos;
+                       line->middle_len = (size_t)(line->value - line->middle);
+                       str_append_data(ctx->name, line->middle, line->middle_len);
+
+                       line->name = str_c(ctx->name);
+                       line->name_len = colon_pos;
+                       line->middle = str_data(ctx->name) + line->name_len + 1;
+               }
        }
 
        if (!line->continued) {

diff --git a/src/lib-mail/test-message-header-parser.c b/src/lib-mail/test-message-header-parser.c
index 58cb7f5577407b6d2fa90aeaa54c264d23e886be..0b3ffc828a9fe35b14972ea074f8e443b671c395 100644 (file)
--- a/src/lib-mail/test-message-header-parser.c
+++ b/src/lib-mail/test-message-header-parser.c
@@ -2,6 +2,7 @@
 
 #include "lib.h"
 #include "str.h"
+#include "strfuncs.h"
 #include "unichar.h"
 #include "istream.h"
 #include "message-size.h"
@@ -245,6 +246,13 @@ static void test_message_header_parser_long_lines(void)
 {
        static const char *lf_str = NAME10": 345\n\n";
        static const char *crlf_str = NAME10": 345\r\n\r\n";
+       static const char *lf_str_vl = NAME1000": Is a long header name\n\n";
+       static const char *crlf_str_vl = NAME1000": Is a long header name\r\n\r\n";
+       static const char *lf_str_ol = NAME1000 \
+               NAME100 ": Is a overlong header name\n\n";
+       static const char *crlf_str_ol = NAME1000 \
+               NAME100 ": Is a overlong header name\r\n\r\n";
+
        struct message_size hdr_size, hdr_size2;
        size_t i, len;
 
@@ -265,6 +273,82 @@ static void test_message_header_parser_long_lines(void)
                test_assert(hdr_size.virtual_size == hdr_size2.virtual_size);
                test_assert(hdr_size.physical_size == hdr_size2.physical_size);
        }
+
+       /* increment these faster, otherwise the test is very slow */
+       len = strlen(lf_str_vl);
+       for (i = 3; i < len; i *= 2) {
+                test_message_header_parser_long_lines_str(lf_str_vl, i, &hdr_size, &hdr_size2);
+                test_assert(hdr_size.physical_size == len);
+                test_assert(hdr_size.virtual_size == len + 2);
+                test_assert(hdr_size.virtual_size == hdr_size2.virtual_size);
+                test_assert(hdr_size.physical_size == hdr_size2.physical_size);
+       }
+       len = strlen(crlf_str_vl);
+       for (i = 3; i < len; i *= 2) {
+               test_message_header_parser_long_lines_str(crlf_str_vl, i, &hdr_size, &hdr_size2);
+               test_assert(hdr_size.physical_size == len);
+               test_assert(hdr_size.virtual_size == len);
+               test_assert(hdr_size.virtual_size == hdr_size2.virtual_size);
+               test_assert(hdr_size.physical_size == hdr_size2.physical_size);
+       }
+
+       /* test that parsing overlength lines work so that name & middle are
+          empty. */
+
+       struct message_header_line *hdr;
+       struct message_header_parser_ctx *ctx;
+       struct istream *input;
+
+       input = test_istream_create(lf_str_ol);
+       ctx = message_parse_header_init(input, NULL, 0);
+
+       test_assert(message_parse_header_next(ctx, &hdr) > 0 &&
+                   *hdr->name == '\0' && hdr->middle == uchar_empty_ptr &&
+                   hdr->name_len == 0 && hdr->middle_len == 0 &&
+                   hdr->value != NULL && hdr->value_len > 0);
+       test_assert(message_parse_header_next(ctx, &hdr) > 0 &&
+                   hdr->eoh);
+       message_parse_header_deinit(&ctx);
+       i_stream_unref(&input);
+
+       input = test_istream_create(crlf_str_ol);
+       ctx = message_parse_header_init(input, NULL, 0);
+       test_assert(message_parse_header_next(ctx, &hdr) > 0 &&
+                   *hdr->name == '\0' && hdr->middle == uchar_empty_ptr &&
+                   hdr->name_len == 0 && hdr->middle_len == 0 &&
+                   hdr->value != NULL && hdr->value_len > 0);
+       test_assert(message_parse_header_next(ctx, &hdr) > 0 &&
+                   hdr->eoh);
+       message_parse_header_deinit(&ctx);
+       i_stream_unref(&input);
+
+       /* test offset parsing */
+       static const char *data = "h1" NAME1000 NAME100 \
+                                  ": value1\r\n" \
+                                  "h2" NAME1000 NAME100 \
+                                  ": value2\r\n" \
+                                  "h3" NAME1000 NAME100 \
+                                  ": value3\r\n\r\n";
+       input = test_istream_create(data);
+       ctx = message_parse_header_init(input, NULL, 0);
+       test_assert(message_parse_header_next(ctx, &hdr) > 0 &&
+                   hdr->full_value[0] == 'h' &&
+                   hdr->full_value[1] == '1' &&
+                   hdr->full_value_offset == 0);
+       test_assert(message_parse_header_next(ctx, &hdr) > 0 &&
+                   hdr->full_value[0] == 'h' &&
+                   hdr->full_value[1] == '2' &&
+                   hdr->full_value_offset == 1112);
+       test_assert(message_parse_header_next(ctx, &hdr) > 0 &&
+                   hdr->full_value[0] == 'h' &&
+                   hdr->full_value[1] == '3' &&
+                   hdr->full_value_offset == 2224);
+       test_assert(message_parse_header_next(ctx, &hdr) > 0 &&
+                   hdr->eoh);
+
+       message_parse_header_deinit(&ctx);
+       i_stream_unref(&input);
+
        test_end();
 }
 
@@ -340,6 +424,35 @@ static void test_message_header_parser_nul(void)
        test_end();
 }
 
+static void test_message_header_parser_extra_crlf_in_name(void)
+{
+       static const unsigned char str[] = "X-Header\r\n  Name: Header Value\n\n";
+       struct message_header_parser_ctx *parser;
+       struct message_header_line *hdr;
+       struct istream *input;
+       test_begin("message header parser CRLF in header name");
+
+       input = test_istream_create_data(str, sizeof(str)-1);
+       parser = message_parse_header_init(input, NULL, 0);
+       hdr = NULL;
+       test_assert(message_parse_header_next(parser, &hdr) > 0 &&
+                   *hdr->name == '\0' && hdr->middle == uchar_empty_ptr &&
+                   hdr->name_len == 0 && hdr->middle_len == 0 &&
+                   hdr->value != NULL && hdr->value_len > 0);
+       test_assert(message_parse_header_next(parser, &hdr) > 0 &&
+                   *hdr->name == '\0' && hdr->middle == uchar_empty_ptr &&
+                   hdr->name_len == 0 && hdr->middle_len == 0 &&
+                   hdr->value != NULL && hdr->value_len > 0 &&
+                   hdr->continued);
+       test_assert(message_parse_header_next(parser, &hdr) > 0 &&
+                   hdr->eoh);
+
+       message_parse_header_deinit(&parser);
+       i_stream_unref(&input);
+
+       test_end();
+}
+
 int main(void)
 {
        static void (*const test_functions[])(void) = {
@@ -349,6 +462,7 @@ int main(void)
                test_message_header_parser_extra_cr_in_eoh,
                test_message_header_parser_no_eoh,
                test_message_header_parser_nul,
+               test_message_header_parser_extra_crlf_in_name,
                NULL
        };
        return test_run(test_functions);