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authorlloyd <[email protected]>2011-12-23 16:17:29 +0000
committerlloyd <[email protected]>2011-12-23 16:17:29 +0000
commit67c1645ae151f5dd0f2bafce926ff8690fd97f19 (patch)
tree9af9c1c22ab58093328cdfd00dbe42292d8b5ed6 /src/tls/tls_reader.h
parentd363602f95f1514b4b595d9912fba2e503edcb21 (diff)
Rename ssl module to tls
Diffstat (limited to 'src/tls/tls_reader.h')
-rw-r--r--src/tls/tls_reader.h186
1 files changed, 186 insertions, 0 deletions
diff --git a/src/tls/tls_reader.h b/src/tls/tls_reader.h
new file mode 100644
index 000000000..3a45235b5
--- /dev/null
+++ b/src/tls/tls_reader.h
@@ -0,0 +1,186 @@
+/*
+* TLS Data Reader
+* (C) 2010 Jack Lloyd
+*
+* Released under the terms of the Botan license
+*/
+
+#ifndef BOTAN_TLS_READER_H__
+#define BOTAN_TLS_READER_H__
+
+#include <botan/secmem.h>
+#include <botan/loadstor.h>
+
+namespace Botan {
+
+/**
+* Helper class for decoding TLS protocol messages
+*/
+class TLS_Data_Reader
+ {
+ public:
+ TLS_Data_Reader(const MemoryRegion<byte>& buf_in) :
+ buf(buf_in), offset(0) {}
+
+ size_t remaining_bytes() const
+ {
+ return buf.size() - offset;
+ }
+
+ bool has_remaining() const
+ {
+ return (remaining_bytes() > 0);
+ }
+
+ void discard_next(size_t bytes)
+ {
+ assert_at_least(bytes);
+ offset += bytes;
+ }
+
+ u16bit get_u16bit()
+ {
+ assert_at_least(2);
+ u16bit result = make_u16bit(buf[offset], buf[offset+1]);
+ offset += 2;
+ return result;
+ }
+
+ byte get_byte()
+ {
+ assert_at_least(1);
+ byte result = buf[offset];
+ offset += 1;
+ return result;
+ }
+
+ template<typename T, typename Container>
+ Container get_elem(size_t num_elems)
+ {
+ assert_at_least(num_elems * sizeof(T));
+
+ Container result(num_elems);
+
+ for(size_t i = 0; i != num_elems; ++i)
+ result[i] = load_be<T>(&buf[offset], i);
+
+ offset += num_elems * sizeof(T);
+
+ return result;
+ }
+
+ template<typename T>
+ SecureVector<T> get_range(size_t len_bytes,
+ size_t min_elems,
+ size_t max_elems)
+ {
+ const size_t num_elems =
+ get_num_elems(len_bytes, sizeof(T), min_elems, max_elems);
+
+ return get_elem<T, SecureVector<T> >(num_elems);
+ }
+
+ template<typename T>
+ std::vector<T> get_range_vector(size_t len_bytes,
+ size_t min_elems,
+ size_t max_elems)
+ {
+ const size_t num_elems =
+ get_num_elems(len_bytes, sizeof(T), min_elems, max_elems);
+
+ return get_elem<T, std::vector<T> >(num_elems);
+ }
+
+ template<typename T>
+ SecureVector<T> get_fixed(size_t size)
+ {
+ return get_elem<T, SecureVector<T> >(size);
+ }
+
+ private:
+ size_t get_length_field(size_t len_bytes)
+ {
+ assert_at_least(len_bytes);
+
+ if(len_bytes == 1)
+ return get_byte();
+ else if(len_bytes == 2)
+ return get_u16bit();
+
+ throw Decoding_Error("TLS_Data_Reader: Bad length size");
+ }
+
+ size_t get_num_elems(size_t len_bytes,
+ size_t T_size,
+ size_t min_elems,
+ size_t max_elems)
+ {
+ const size_t byte_length = get_length_field(len_bytes);
+
+ if(byte_length % T_size != 0)
+ throw Decoding_Error("TLS_Data_Reader: Size isn't multiple of T");
+
+ const size_t num_elems = byte_length / T_size;
+
+ if(num_elems < min_elems || num_elems > max_elems)
+ throw Decoding_Error("TLS_Data_Reader: Range outside paramaters");
+
+ return num_elems;
+ }
+
+ void assert_at_least(size_t n) const
+ {
+ if(buf.size() - offset < n)
+ throw Decoding_Error("TLS_Data_Reader: Corrupt packet");
+ }
+
+ const MemoryRegion<byte>& buf;
+ size_t offset;
+ };
+
+/**
+* Helper function for encoding length-tagged vectors
+*/
+template<typename T>
+void append_tls_length_value(MemoryRegion<byte>& buf,
+ const T* vals,
+ size_t vals_size,
+ size_t tag_size)
+ {
+ const size_t T_size = sizeof(T);
+ const size_t val_bytes = T_size * vals_size;
+
+ if(tag_size != 1 && tag_size != 2)
+ throw std::invalid_argument("append_tls_length_value: invalid tag size");
+
+ if((tag_size == 1 && val_bytes > 255) ||
+ (tag_size == 2 && val_bytes > 65535))
+ throw std::invalid_argument("append_tls_length_value: value too large");
+
+ for(size_t i = 0; i != tag_size; ++i)
+ buf.push_back(get_byte(sizeof(val_bytes)-tag_size+i, val_bytes));
+
+ for(size_t i = 0; i != vals_size; ++i)
+ for(size_t j = 0; j != T_size; ++j)
+ buf.push_back(get_byte(j, vals[i]));
+ }
+
+template<typename T>
+void append_tls_length_value(MemoryRegion<byte>& buf,
+ const MemoryRegion<T>& vals,
+ size_t tag_size)
+ {
+ append_tls_length_value(buf, &vals[0], vals.size(), tag_size);
+ }
+
+template<typename T>
+void append_tls_length_value(MemoryRegion<byte>& buf,
+ const std::vector<T>& vals,
+ size_t tag_size)
+ {
+ append_tls_length_value(buf, &vals[0], vals.size(), tag_size);
+ }
+
+}
+
+#endif