New upstream version 5.7.2

1 files changed, 75 insertions, 35 deletions

diff --git a/src/libstrongswan/plugins/curve25519/curve25519_public_key.c b/src/libstrongswan/plugins/curve25519/curve25519_public_key.c
index 1d4dec565..dfc1df4d0 100644
--- a/src/libstrongswan/plugins/curve25519/curve25519_public_key.c
+++ b/src/libstrongswan/plugins/curve25519/curve25519_public_key.c
@@ -1,4 +1,5 @@
 /*
+ * Copyright (C) 2018 Tobias Brunner
  * Copyright (C) 2016 Andreas Steffen
  * HSR Hochschule fuer Technik Rapperswil
  *
@@ -48,6 +49,13 @@ METHOD(public_key_t, get_type, key_type_t,
 	return KEY_ED25519;
 }
 
+/* L = 2^252+27742317777372353535851937790883648493 in little-endian form */
+static chunk_t curve25519_order = chunk_from_chars(
+								0xed, 0xd3, 0xf5, 0x5c, 0x1a, 0x63, 0x12, 0x58,
+								0xd6, 0x9c, 0xf7, 0xa2, 0xde, 0xf9, 0xde, 0x14,
+								0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+								0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10);
+
 METHOD(public_key_t, verify, bool,
 	private_curve25519_public_key_t *this, signature_scheme_t scheme,
 	void *params, chunk_t data, chunk_t signature)
@@ -93,6 +101,20 @@ METHOD(public_key_t, verify, bool,
 	{
 		return FALSE;
 	}
+	/* make sure 0 <= s < L, as per RFC 8032, section 5.1.7 to prevent signature
+	 * malleability.  Due to the three-bit check above (forces s < 2^253) there
+	 * is not that much room, but adding L once works with most signatures */
+	for (i = 31; ; i--)
+	{
+		if (sig[i+32] < curve25519_order.ptr[i])
+		{
+			break;
+		}
+		else if (sig[i+32] > curve25519_order.ptr[i] || i == 0)
+		{
+			return FALSE;
+		}
+	}
 
 	hasher = lib->crypto->create_hasher(lib->crypto, HASH_SHA512);
 	if (!hasher)
@@ -200,22 +222,68 @@ static const asn1Object_t pubkeyObjects[] = {
 #define ED25519_SUBJECT_PUBLIC_KEY				2
 
 /**
+ * Parse the ASN.1-encoded subjectPublicKeyInfo
+ */
+static bool parse_public_key_info(private_curve25519_public_key_t *this,
+								  chunk_t blob)
+{
+	asn1_parser_t *parser;
+	chunk_t object;
+	bool success = FALSE;
+	int objectID, oid;
+
+	parser = asn1_parser_create(pubkeyObjects, blob);
+
+	while (parser->iterate(parser, &objectID, &object))
+	{
+		switch (objectID)
+		{
+			case ED25519_SUBJECT_PUBLIC_KEY_ALGORITHM:
+			{
+				oid = asn1_parse_algorithmIdentifier(object,
+										parser->get_level(parser) + 1, NULL);
+				if (oid != OID_ED25519)
+				{
+					goto end;
+				}
+				break;
+			}
+			case ED25519_SUBJECT_PUBLIC_KEY:
+			{
+				/* encoded as an ASN1 BIT STRING */
+				if (object.len != 1 + ED25519_KEY_LEN)
+				{
+					goto end;
+				}
+				this->pubkey = chunk_clone(chunk_skip(object, 1));
+				break;
+			}
+		}
+	}
+	success = parser->success(parser);
+
+end:
+	parser->destroy(parser);
+	return success;
+}
+
+/**
  * See header.
  */
 curve25519_public_key_t *curve25519_public_key_load(key_type_t type,
 													va_list args)
 {
 	private_curve25519_public_key_t *this;
-	chunk_t blob = chunk_empty, object;
-	asn1_parser_t *parser;
-	bool success = FALSE;
-	int objectID, oid;
+	chunk_t asn1 = chunk_empty, blob = chunk_empty;
 
 	while (TRUE)
 	{
 		switch (va_arg(args, builder_part_t))
 		{
 			case BUILD_BLOB_ASN1_DER:
+				asn1 = va_arg(args, chunk_t);
+				continue;
+			case BUILD_EDDSA_PUB:
 				blob = va_arg(args, chunk_t);
 				continue;
 			case BUILD_END:
@@ -244,39 +312,11 @@ curve25519_public_key_t *curve25519_public_key_load(key_type_t type,
 		.ref = 1,
 	);
 
-	parser = asn1_parser_create(pubkeyObjects, blob);
-
-	while (parser->iterate(parser, &objectID, &object))
+	if (blob.len == ED25519_KEY_LEN)
 	{
-		switch (objectID)
-		{
-			case ED25519_SUBJECT_PUBLIC_KEY_ALGORITHM:
-			{
-				oid = asn1_parse_algorithmIdentifier(object,
-										parser->get_level(parser) + 1, NULL);
-				if (oid != OID_ED25519)
-				{
-					goto end;
-				}
-				break;
-			}
-			case ED25519_SUBJECT_PUBLIC_KEY:
-			{
-				/* encoded as an ASN1 BIT STRING */
-				if (object.len != 1 + ED25519_KEY_LEN)
-				{
-					goto end;
-				}
-				this->pubkey = chunk_clone(chunk_skip(object, 1));
-				break;
-			}
-		}
+		this->pubkey = chunk_clone(blob);
 	}
-	success = parser->success(parser);
-
-end:
-	parser->destroy(parser);
-	if (!success)
+	else if (!asn1.len || !parse_public_key_info(this, asn1))
 	{
 		destroy(this);
 		return NULL;