Fix for 280121 - allow encoding simple templates with SEC_ASN1_INLINE and SEC_ASN1_OPTIONAL . r=nelson

3 files changed, 63 insertions, 3 deletions

diff --git a/security/nss/lib/util/secasn1.h b/security/nss/lib/util/secasn1.h
index 5c414522e..5e4779d57 100644
--- a/security/nss/lib/util/secasn1.h
+++ b/security/nss/lib/util/secasn1.h
@@ -183,6 +183,11 @@ extern const SEC_ASN1Template *
 SEC_ASN1GetSubtemplate (const SEC_ASN1Template *inTemplate, void *thing,
 			PRBool encoding);
 
+/* whether the template is for a primitive type or a choice of
+ * primitive types
+ */
+extern PRBool SEC_ASN1IsTemplateSimple(const SEC_ASN1Template *theTemplate);
+
 /************************************************************************/
 
 /*
diff --git a/security/nss/lib/util/secasn1e.c b/security/nss/lib/util/secasn1e.c
index 8a7e33207..778aff08c 100644
--- a/security/nss/lib/util/secasn1e.c
+++ b/security/nss/lib/util/secasn1e.c
@@ -193,6 +193,7 @@ sec_asn1e_init_state_based_on_template (sec_asn1e_state *state)
     unsigned char tag_modifiers;
     unsigned long encode_kind, under_kind;
     unsigned long tag_number;
+    PRBool isInline = PR_FALSE;
 
 
     encode_kind = state->theTemplate->kind;
@@ -222,7 +223,7 @@ sec_asn1e_init_state_based_on_template (sec_asn1e_state *state)
     } else if ((encode_kind & (SEC_ASN1_POINTER | SEC_ASN1_INLINE)) || 
         (!universal && !isExplicit)) {
 	const SEC_ASN1Template *subt;
-	void *src;
+	void *src = NULL;
 
 	PORT_Assert ((encode_kind & (SEC_ASN1_ANY | SEC_ASN1_SKIP)) == 0);
 
@@ -231,6 +232,7 @@ sec_asn1e_init_state_based_on_template (sec_asn1e_state *state)
 	if (encode_kind & SEC_ASN1_POINTER) {
 	    src = *(void **)state->src;
 	    state->place = afterPointer;
+
 	    if (src == NULL) {
 		/*
 		 * If this is optional, but NULL, then the field does
@@ -249,8 +251,9 @@ sec_asn1e_init_state_based_on_template (sec_asn1e_state *state)
 	    src = state->src;
 	    if (encode_kind & SEC_ASN1_INLINE) {
 		/* check that there are no extraneous bits */
-		PORT_Assert (encode_kind == SEC_ASN1_INLINE && !optional);
+		/* PORT_Assert (encode_kind == SEC_ASN1_INLINE && !optional); */
 		state->place = afterInline;
+		isInline = PR_TRUE;
 	    } else {
 		/*
 		 * Save the tag modifiers and tag number here before moving
@@ -268,6 +271,22 @@ sec_asn1e_init_state_based_on_template (sec_asn1e_state *state)
 	}
 
 	subt = SEC_ASN1GetSubtemplate (state->theTemplate, state->src, PR_TRUE);
+	if (isInline && optional) {
+	    /* we only handle a very limited set of optional inline cases at
+	       this time */
+	    if (PR_FALSE != SEC_ASN1IsTemplateSimple(subt)) {
+		/* we now know that the target is a SECItem*, so we can check
+		   if the source contains one */
+		SECItem* target = (SECItem*)state->src;
+		if (!target || !target->data || !target->len) {
+		    /* no valid data to encode subtemplate */
+		    return state;
+		}
+	    } else {
+		PORT_Assert(0); /* complex templates are not handled as
+				   inline optional */
+	    }
+	}
 	state = sec_asn1e_push_state (state->top, subt, src, PR_FALSE);
 	if (state == NULL)
 	    return state;
@@ -552,7 +571,21 @@ sec_asn1e_contents_length (const SEC_ASN1Template *theTemplate, void *src,
 	    }
 	} else if (encode_kind & SEC_ASN1_INLINE) {
 	    /* check that there are no extraneous bits */
-	    PORT_Assert (encode_kind == SEC_ASN1_INLINE && !optional);
+	    if (optional) {
+		if (PR_FALSE != SEC_ASN1IsTemplateSimple(theTemplate)) {
+		    /* we now know that the target is a SECItem*, so we can check
+		       if the source contains one */
+		    SECItem* target = (SECItem*)src;
+		    if (!target || !target->data || !target->len) {
+			/* no valid data to encode subtemplate */
+			*noheaderp = PR_TRUE;
+			return 0;
+		    }
+		} else {
+		    PORT_Assert(0); /* complex templates not handled as inline
+                                       optional */
+		}
+	    }
 	}
 
 	src = (char *)src + theTemplate->offset;
diff --git a/security/nss/lib/util/secasn1u.c b/security/nss/lib/util/secasn1u.c
index 2de4f2753..1514bd7ed 100644
--- a/security/nss/lib/util/secasn1u.c
+++ b/security/nss/lib/util/secasn1u.c
@@ -107,3 +107,25 @@ SEC_ASN1GetSubtemplate (const SEC_ASN1Template *theTemplate, void *thing,
     }
     return subt;
 }
+
+PRBool SEC_ASN1IsTemplateSimple(const SEC_ASN1Template *theTemplate)
+{
+    if (!theTemplate) {
+	return PR_TRUE; /* it doesn't get any simpler than NULL */
+    }
+    /* only templates made of one primitive type or a choice of primitive
+       types are considered simple */
+    if (! (theTemplate->kind & (~SEC_ASN1_TAGNUM_MASK))) {
+	return PR_TRUE; /* primitive type */
+    }
+    if (!theTemplate->kind & SEC_ASN1_CHOICE) {
+	return PR_FALSE; /* no choice means not simple */
+    }
+    while (++theTemplate && theTemplate->kind) {
+	if (theTemplate->kind & (~SEC_ASN1_TAGNUM_MASK)) {
+	    return PR_FALSE; /* complex type */
+	}
+    }
+    return PR_TRUE; /* choice of primitive types */
+}
+