[Fix] Fix start of body detection in DKIM

diff --git a/src/libserver/dkim.c b/src/libserver/dkim.c
index cdad6365c1d76d9c3171134ddfc4d268aa5b33b1..4d6fc69404f0cf90484b5a94292660b425d17b9a 100644 (file)
--- a/src/libserver/dkim.c
+++ b/src/libserver/dkim.c
@@ -1878,6 +1878,44 @@ rspamd_dkim_canonize_header (struct rspamd_dkim_common_ctx *ctx,
        return FALSE;
 }
 
+static inline const gchar *
+rspamd_dkim_body_start (const gchar *headers_end, const gchar *body_end)
+{
+       const gchar *p = headers_end;
+       enum {
+               st_start = 0,
+               st_cr,
+               st_lf,
+       } state = st_start;
+
+       if (headers_end + 1 >= body_end) {
+               return headers_end;
+       }
+
+       switch (state) {
+       case st_start:
+               if (*p == '\r') {
+                       p ++;
+                       state = st_cr;
+               }
+               else if (*p == '\n') {
+                       p ++;
+                       state = st_lf;
+               }
+               break;
+       case st_cr:
+               if (*p == '\n' && p < body_end) {
+                       /* CRLF */
+                       p ++;
+               }
+               break;
+       case st_lf:
+               break;
+       }
+
+       return p;
+}
+
 /**
  * Check task for dkim context using dkim key
  * @param ctx dkim verify context
@@ -1890,7 +1928,7 @@ rspamd_dkim_check (rspamd_dkim_context_t *ctx,
        rspamd_dkim_key_t *key,
        struct rspamd_task *task)
 {
-       const gchar *p, *headers_end = NULL, *body_end;
+       const gchar *p, *headers_end = NULL, *body_end, *body_start;
        guchar raw_digest[EVP_MAX_MD_SIZE];
        gsize dlen;
        gint res = DKIM_CONTINUE;
@@ -1907,13 +1945,10 @@ rspamd_dkim_check (rspamd_dkim_context_t *ctx,
        body_end = task->msg.begin + task->msg.len;
        headers_end = task->msg.begin + task->raw_headers_content.len;
 
-       while ((*headers_end == '\r' || *headers_end == '\n') &&
-                       headers_end < body_end) {
-               headers_end ++;
-       }
+       body_start = rspamd_dkim_body_start (headers_end, body_end);
 
        /* Start canonization of body part */
-       if (!rspamd_dkim_canonize_body (&ctx->common, headers_end, body_end)) {
+       if (!rspamd_dkim_canonize_body (&ctx->common, body_start, body_end)) {
                return DKIM_RECORD_ERROR;
        }
        /* Now canonize headers */
@@ -2153,7 +2188,7 @@ rspamd_dkim_sign (struct rspamd_task *task,
 {
        GString *hdr;
        struct rspamd_dkim_header *dh;
-       const gchar *p, *headers_end = NULL, *body_end;
+       const gchar *p, *headers_end = NULL, *body_end, *body_start;
        guchar raw_digest[EVP_MAX_MD_SIZE];
        gsize dlen;
        guint i, j;
@@ -2167,13 +2202,14 @@ rspamd_dkim_sign (struct rspamd_task *task,
        p = task->msg.begin;
        body_end = task->msg.begin + task->msg.len;
        headers_end = task->msg.begin + task->raw_headers_content.len;
+       body_start = rspamd_dkim_body_start (headers_end, body_end);
 
        if (len > 0) {
                ctx->common.len = len;
        }
 
        /* Start canonization of body part */
-       if (!rspamd_dkim_canonize_body (&ctx->common, headers_end, body_end)) {
+       if (!rspamd_dkim_canonize_body (&ctx->common, body_start, body_end)) {
                return NULL;
        }