PR: 2742
Reported by: Dmitry Belyavsky <beldmit@gmail.com>

If resigning with detached content in CMS just copy data across.

crypto/asn1/asn_mime.c

diff --git a/crypto/asn1/asn_mime.c b/crypto/asn1/asn_mime.c
index 42536f7..6d8a9bf 100644
--- a/crypto/asn1/asn_mime.c
+++ b/crypto/asn1/asn_mime.c
@@ -377,8 +377,12 @@
 	BIO *tmpbio;
 	const ASN1_AUX *aux = it->funcs;
 	ASN1_STREAM_ARG sarg;
+	int rv = 1;
 
-	if (!(flags & SMIME_DETACHED))
+	/* If data is not deteched or resigning then the output BIO is
+	 * already set up to finalise when it is written through.
+	 */
+	if (!(flags & SMIME_DETACHED) || (flags & PKCS7_REUSE_DIGEST))
 		{
 		SMIME_crlf_copy(data, out, flags);
 		return 1;
@@ -405,7 +409,7 @@
 
 	/* Finalize structure */
 	if (aux->asn1_cb(ASN1_OP_DETACHED_POST, &val, it, &sarg) <= 0)
-		return 0;
+		rv = 0;
 
 	/* Now remove any digests prepended to the BIO */
 
@@ -416,7 +420,7 @@
 		sarg.ndef_bio = tmpbio;
 		}
 
-	return 1;
+	return rv;
 
 	}