diff --git a/CHANGES b/CHANGES
index b9490b1870add976fedd15bcd0f81f9552b2c04f..9974ccbfbea8c03712122f132719f7f96d06c846 100644
--- a/CHANGES
+++ b/CHANGES
@@ -814,6 +814,10 @@
 
  Changes between 0.9.8k and 0.9.8l  [xx XXX xxxx]
 
+  *) Don't allow the use of leading 0x80 in OIDs. This is a violation of
+     X690 8.9.12 and can produce some misleading textual output of OIDs.
+     [Steve Henson, reported by Dan Kaminsky]
+
   *) Add compression id to {d2i,i2d}_SSL_SESSION so it is correctly saved
      and restored.
      [Steve Henson]
diff --git a/crypto/asn1/a_object.c b/crypto/asn1/a_object.c
index f1a5a1e31e4a9367c0a657df1b9c782a44f5ed99..bd2d5a2d824458237c9c2706db3d6dc46b0dae0c 100644
--- a/crypto/asn1/a_object.c
+++ b/crypto/asn1/a_object.c
@@ -290,6 +290,17 @@ ASN1_OBJECT *c2i_ASN1_OBJECT(ASN1_OBJECT **a, const unsigned char **pp,
 	const unsigned char *p;
 	unsigned char *data;
 	int i;
+	/* Sanity check OID encoding: can't have 0x80 in subidentifiers, see:
+	 * X.690 8.19.2
+	 */
+	for (i = 0, p = *pp + 1; i < len - 1; i++, p++)
+		{
+		if (*p == 0x80)
+			{
+			ASN1err(ASN1_F_C2I_ASN1_OBJECT,ASN1_R_INVALID_OBJECT_ENCODING);
+			return NULL;
+			}
+		}
 
 	/* only the ASN1_OBJECTs from the 'table' will have values
 	 * for ->sn or ->ln */
diff --git a/crypto/asn1/asn1.h b/crypto/asn1/asn1.h
index c1af4e7943ea3325174f475651279a7f19da7670..f202e23841b7a98446630e90ffda7b48d2ddbb12 100644
--- a/crypto/asn1/asn1.h
+++ b/crypto/asn1/asn1.h
@@ -1328,6 +1328,7 @@ void ERR_load_ASN1_strings(void);
 #define ASN1_R_INVALID_MIME_TYPE			 205
 #define ASN1_R_INVALID_MODIFIER				 186
 #define ASN1_R_INVALID_NUMBER				 187
+#define ASN1_R_INVALID_OBJECT_ENCODING			 216
 #define ASN1_R_INVALID_SEPARATOR			 131
 #define ASN1_R_INVALID_TIME_FORMAT			 132
 #define ASN1_R_INVALID_UNIVERSALSTRING_LENGTH		 133
diff --git a/crypto/asn1/asn1_err.c b/crypto/asn1/asn1_err.c
index 664f158bb30c7a3923d89690709eb8b56dcc9830..6e04d08f314335af5ef7cd435a36bd5182f1e4a4 100644
--- a/crypto/asn1/asn1_err.c
+++ b/crypto/asn1/asn1_err.c
@@ -1,6 +1,6 @@
 /* crypto/asn1/asn1_err.c */
 /* ====================================================================
- * Copyright (c) 1999-2008 The OpenSSL Project.  All rights reserved.
+ * Copyright (c) 1999-2009 The OpenSSL Project.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -248,6 +248,7 @@ static ERR_STRING_DATA ASN1_str_reasons[]=
 {ERR_REASON(ASN1_R_INVALID_MIME_TYPE)    ,"invalid mime type"},
 {ERR_REASON(ASN1_R_INVALID_MODIFIER)     ,"invalid modifier"},
 {ERR_REASON(ASN1_R_INVALID_NUMBER)       ,"invalid number"},
+{ERR_REASON(ASN1_R_INVALID_OBJECT_ENCODING),"invalid object encoding"},
 {ERR_REASON(ASN1_R_INVALID_SEPARATOR)    ,"invalid separator"},
 {ERR_REASON(ASN1_R_INVALID_TIME_FORMAT)  ,"invalid time format"},
 {ERR_REASON(ASN1_R_INVALID_UNIVERSALSTRING_LENGTH),"invalid universalstring length"},