From: Dr. Stephen Henson <steve@openssl.org>
Date: Wed, 6 Oct 2010 18:00:59 +0000 (+0000)
Subject: We can't always read 6 bytes in an OCSP response: fix so error statuses
X-Git-Tag: OpenSSL-fips-2_0-rc1~963
X-Git-Url: https://git.openssl.org/?p=openssl.git;a=commitdiff_plain;h=983768997e28c908fbcb7b827f9f4e4721e74a65;hp=8ec3fa0597224abf3bdcb59da0f02f3100f75459

We can't always read 6 bytes in an OCSP response: fix so error statuses
are read correctly for non-blocking I/O.
---

diff --git a/crypto/ocsp/ocsp_ht.c b/crypto/ocsp/ocsp_ht.c
index 12bbfcffd1..af5fc16691 100644
--- a/crypto/ocsp/ocsp_ht.c
+++ b/crypto/ocsp/ocsp_ht.c
@@ -397,11 +397,12 @@ int OCSP_sendreq_nbio(OCSP_RESPONSE **presp, OCSP_REQ_CTX *rctx)
 
 
 		case OHS_ASN1_HEADER:
-		/* Now reading ASN1 header: can read at least 6 bytes which
-		 * is more than enough for any valid ASN1 SEQUENCE header
+		/* Now reading ASN1 header: can read at least 2 bytes which
+		 * is enough for ASN1 SEQUENCE header and either length field
+		 * or at least the length of the length field.
 		 */
 		n = BIO_get_mem_data(rctx->mem, &p);
-		if (n < 6)
+		if (n < 2)
 			goto next_io;
 
 		/* Check it is an ASN1 SEQUENCE */
@@ -414,6 +415,11 @@ int OCSP_sendreq_nbio(OCSP_RESPONSE **presp, OCSP_REQ_CTX *rctx)
 		/* Check out length field */
 		if (*p & 0x80)
 			{
+			/* If MSB set on initial length octet we can now
+			 * always read 6 octets: make sure we have them.
+			 */
+			if (n < 6)
+				goto next_io;
 			n = *p & 0x7F;
 			/* Not NDEF or excessive length */
 			if (!n || (n > 4))