BER decoder extras needed by previous commit

2 files changed, 68 insertions, 17 deletions

diff --git a/src/asn1/ber_dec.cpp b/src/asn1/ber_dec.cpp
index b31c7b903..faea4cb94 100644
--- a/src/asn1/ber_dec.cpp
+++ b/src/asn1/ber_dec.cpp
@@ -400,6 +400,28 @@ BER_Decoder& BER_Decoder::decode(size_t& out,
    }
 
 /*
+* Decode a small BER encoded INTEGER
+*/
+u64bit BER_Decoder::decode_constrained_integer(ASN1_Tag type_tag,
+                                               ASN1_Tag class_tag,
+                                               size_t T_bytes)
+   {
+   if(T_bytes > 8)
+      throw BER_Decoding_Error("Can't decode small integer over 8 bytes");
+
+   BigInt integer;
+   decode(integer, type_tag, class_tag);
+
+   if(integer.bits() > 8*T_bytes)
+      throw BER_Decoding_Error("Decoded integer value larger than expected");
+
+   u64bit out = 0;
+   for(size_t i = 0; i != 8; ++i)
+      out = (out << 8) | integer.byte_at(8-i);
+   return out;
+   }
+
+/*
 * Decode a BER encoded INTEGER
 */
 BER_Decoder& BER_Decoder::decode(BigInt& out,
diff --git a/src/asn1/ber_dec.h b/src/asn1/ber_dec.h
index 5f79d3fc1..f8b8a704a 100644
--- a/src/asn1/ber_dec.h
+++ b/src/asn1/ber_dec.h
@@ -20,33 +20,61 @@ class BOTAN_DLL BER_Decoder
    {
    public:
       BER_Object get_next_object();
-      void push_back(const BER_Object&);
+      void push_back(const BER_Object& obj);
 
       bool more_items() const;
       BER_Decoder& verify_end();
       BER_Decoder& discard_remaining();
 
-      BER_Decoder  start_cons(ASN1_Tag, ASN1_Tag = UNIVERSAL);
+      BER_Decoder  start_cons(ASN1_Tag type_tag, ASN1_Tag class_tag = UNIVERSAL);
       BER_Decoder& end_cons();
 
-      BER_Decoder& raw_bytes(MemoryRegion<byte>&);
+      BER_Decoder& raw_bytes(MemoryRegion<byte>& v);
 
       BER_Decoder& decode_null();
-      BER_Decoder& decode(bool&);
-      BER_Decoder& decode(size_t&);
-      BER_Decoder& decode(class BigInt&);
-      BER_Decoder& decode(MemoryRegion<byte>&, ASN1_Tag);
+      BER_Decoder& decode(bool& v);
+      BER_Decoder& decode(size_t& v);
+      BER_Decoder& decode(class BigInt& v);
+      BER_Decoder& decode(MemoryRegion<byte>& v, ASN1_Tag type_tag);
 
-      BER_Decoder& decode(bool&, ASN1_Tag, ASN1_Tag = CONTEXT_SPECIFIC);
-      BER_Decoder& decode(size_t&, ASN1_Tag, ASN1_Tag = CONTEXT_SPECIFIC);
-      BER_Decoder& decode(class BigInt&,
-                          ASN1_Tag, ASN1_Tag = CONTEXT_SPECIFIC);
-      BER_Decoder& decode(MemoryRegion<byte>&, ASN1_Tag,
-                          ASN1_Tag, ASN1_Tag = CONTEXT_SPECIFIC);
+      BER_Decoder& decode(bool& v,
+                          ASN1_Tag type_tag,
+                          ASN1_Tag class_tag = CONTEXT_SPECIFIC);
 
-      BER_Decoder& decode(class ASN1_Object&);
+      BER_Decoder& decode(size_t& v,
+                          ASN1_Tag type_tag,
+                          ASN1_Tag class_tag = CONTEXT_SPECIFIC);
 
-      BER_Decoder& decode_octet_string_bigint(class BigInt&);
+      BER_Decoder& decode(class BigInt& v,
+                          ASN1_Tag type_tag,
+                          ASN1_Tag class_tag = CONTEXT_SPECIFIC);
+
+      BER_Decoder& decode(MemoryRegion<byte>& v,
+                          ASN1_Tag real_type,
+                          ASN1_Tag type_tag,
+                          ASN1_Tag class_tag = CONTEXT_SPECIFIC);
+
+      BER_Decoder& decode(class ASN1_Object& obj);
+
+      BER_Decoder& decode_octet_string_bigint(class BigInt& b);
+
+      u64bit decode_constrained_integer(ASN1_Tag type_tag,
+                                        ASN1_Tag class_tag,
+                                        size_t T_bytes);
+
+      template<typename T> BER_Decoder& decode_integer_type(T& out)
+         {
+         return decode_integer_type<T>(out, INTEGER, UNIVERSAL);
+         }
+
+      template<typename T>
+         BER_Decoder& decode_integer_type(T& out,
+                                          ASN1_Tag type_tag,
+                                          ASN1_Tag class_tag = CONTEXT_SPECIFIC)
+         {
+         out = decode_constrained_integer(type_tag, class_tag, sizeof(out));
+         return (*this);
+         }
 
       template<typename T>
          BER_Decoder& decode_optional(T& out,
@@ -71,8 +99,9 @@ class BOTAN_DLL BER_Decoder
          return (*this);
          }
 
-      BER_Decoder& decode_optional_string(MemoryRegion<byte>&,
-                                          ASN1_Tag, u16bit);
+      BER_Decoder& decode_optional_string(MemoryRegion<byte>& out,
+                                          ASN1_Tag real_type,
+                                          u16bit type_no);
 
       BER_Decoder(DataSource&);
       BER_Decoder(const byte[], size_t);