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authorlloyd <[email protected]>2008-09-28 19:29:24 +0000
committerlloyd <[email protected]>2008-09-28 19:29:24 +0000
commit9bcfe627321ddc81691b835dffaa6324ac4684a4 (patch)
treefe5e8ae9813b853549558b59833022e87e83981b /src/pk_pad/emsa4
parent9822a701516396b7de4e41339faecd48ff8dc8ff (diff)
Move all modules into src/ directory
Diffstat (limited to 'src/pk_pad/emsa4')
-rw-r--r--src/pk_pad/emsa4/emsa4.cpp144
-rw-r--r--src/pk_pad/emsa4/emsa4.h38
-rw-r--r--src/pk_pad/emsa4/modinfo.txt10
3 files changed, 192 insertions, 0 deletions
diff --git a/src/pk_pad/emsa4/emsa4.cpp b/src/pk_pad/emsa4/emsa4.cpp
new file mode 100644
index 000000000..9821c1f13
--- /dev/null
+++ b/src/pk_pad/emsa4/emsa4.cpp
@@ -0,0 +1,144 @@
+/*************************************************
+* EMSA4 Source File *
+* (C) 1999-2007 Jack Lloyd *
+*************************************************/
+
+#include <botan/emsa4.h>
+#include <botan/lookup.h>
+#include <botan/look_pk.h>
+#include <botan/bit_ops.h>
+
+namespace Botan {
+
+/*************************************************
+* EMSA4 Update Operation *
+*************************************************/
+void EMSA4::update(const byte input[], u32bit length)
+ {
+ hash->update(input, length);
+ }
+
+/*************************************************
+* Return the raw (unencoded) data *
+*************************************************/
+SecureVector<byte> EMSA4::raw_data()
+ {
+ return hash->final();
+ }
+
+/*************************************************
+* EMSA4 Encode Operation *
+*************************************************/
+SecureVector<byte> EMSA4::encoding_of(const MemoryRegion<byte>& msg,
+ u32bit output_bits,
+ RandomNumberGenerator& rng)
+ {
+ const u32bit HASH_SIZE = hash->OUTPUT_LENGTH;
+
+ if(msg.size() != HASH_SIZE)
+ throw Encoding_Error("EMSA4::encoding_of: Bad input length");
+ if(output_bits < 8*HASH_SIZE + 8*SALT_SIZE + 9)
+ throw Encoding_Error("EMSA4::encoding_of: Output length is too small");
+
+ const u32bit output_length = (output_bits + 7) / 8;
+
+ SecureVector<byte> salt(SALT_SIZE);
+ rng.randomize(salt, SALT_SIZE);
+
+ for(u32bit j = 0; j != 8; ++j)
+ hash->update(0);
+ hash->update(msg);
+ hash->update(salt, SALT_SIZE);
+ SecureVector<byte> H = hash->final();
+
+ SecureVector<byte> EM(output_length);
+
+ EM[output_length - HASH_SIZE - SALT_SIZE - 2] = 0x01;
+ EM.copy(output_length - 1 - HASH_SIZE - SALT_SIZE, salt, SALT_SIZE);
+ mgf->mask(H, HASH_SIZE, EM, output_length - HASH_SIZE - 1);
+ EM[0] &= 0xFF >> (8 * ((output_bits + 7) / 8) - output_bits);
+ EM.copy(output_length - 1 - HASH_SIZE, H, HASH_SIZE);
+ EM[output_length-1] = 0xBC;
+
+ return EM;
+ }
+
+/*************************************************
+* EMSA4 Decode/Verify Operation *
+*************************************************/
+bool EMSA4::verify(const MemoryRegion<byte>& const_coded,
+ const MemoryRegion<byte>& raw, u32bit key_bits) throw()
+ {
+ const u32bit HASH_SIZE = hash->OUTPUT_LENGTH;
+ const u32bit KEY_BYTES = (key_bits + 7) / 8;
+
+ if(key_bits < 8*HASH_SIZE + 9)
+ return false;
+ if(raw.size() != HASH_SIZE)
+ return false;
+ if(const_coded.size() > KEY_BYTES)
+ return false;
+ if(const_coded[const_coded.size()-1] != 0xBC)
+ return false;
+
+ SecureVector<byte> coded = const_coded;
+ if(coded.size() < KEY_BYTES)
+ {
+ SecureVector<byte> temp(KEY_BYTES);
+ temp.copy(KEY_BYTES - coded.size(), coded, coded.size());
+ coded = temp;
+ }
+
+ const u32bit TOP_BITS = 8 * ((key_bits + 7) / 8) - key_bits;
+ if(TOP_BITS > 8 - high_bit(coded[0]))
+ return false;
+
+ SecureVector<byte> DB(coded.begin(), coded.size() - HASH_SIZE - 1);
+ SecureVector<byte> H(coded + coded.size() - HASH_SIZE - 1, HASH_SIZE);
+
+ mgf->mask(H, H.size(), DB, coded.size() - H.size() - 1);
+ DB[0] &= 0xFF >> TOP_BITS;
+
+ u32bit salt_offset = 0;
+ for(u32bit j = 0; j != DB.size(); ++j)
+ {
+ if(DB[j] == 0x01)
+ { salt_offset = j + 1; break; }
+ if(DB[j])
+ return false;
+ }
+ if(salt_offset == 0)
+ return false;
+
+ SecureVector<byte> salt(DB + salt_offset, DB.size() - salt_offset);
+
+ for(u32bit j = 0; j != 8; ++j)
+ hash->update(0);
+ hash->update(raw);
+ hash->update(salt);
+ SecureVector<byte> H2 = hash->final();
+
+ return (H == H2);
+ }
+
+/*************************************************
+* EMSA4 Constructor *
+*************************************************/
+EMSA4::EMSA4(const std::string& hash_name, const std::string& mgf_name) :
+ SALT_SIZE(output_length_of(hash_name))
+ {
+ hash = get_hash(hash_name);
+ mgf = get_mgf(mgf_name + "(" + hash_name + ")");
+ }
+
+/*************************************************
+* EMSA4 Constructor *
+*************************************************/
+EMSA4::EMSA4(const std::string& hash_name, const std::string& mgf_name,
+ u32bit salt_size) : SALT_SIZE(salt_size)
+ {
+ hash = get_hash(hash_name);
+ mgf = get_mgf(mgf_name + "(" + hash_name + ")");
+ }
+
+}
diff --git a/src/pk_pad/emsa4/emsa4.h b/src/pk_pad/emsa4/emsa4.h
new file mode 100644
index 000000000..f4d4a4b6d
--- /dev/null
+++ b/src/pk_pad/emsa4/emsa4.h
@@ -0,0 +1,38 @@
+/*************************************************
+* EMSA4 Header File *
+* (C) 1999-2007 Jack Lloyd *
+*************************************************/
+
+#ifndef BOTAN_EMSA4_H__
+#define BOTAN_EMSA4_H__
+
+#include <botan/pk_util.h>
+
+namespace Botan {
+
+/*************************************************
+* EMSA4 *
+*************************************************/
+class BOTAN_DLL EMSA4 : public EMSA
+ {
+ public:
+ EMSA4(const std::string&, const std::string&);
+ EMSA4(const std::string&, const std::string&, u32bit);
+ ~EMSA4() { delete hash; delete mgf; }
+ private:
+ void update(const byte[], u32bit);
+ SecureVector<byte> raw_data();
+
+ SecureVector<byte> encoding_of(const MemoryRegion<byte>&, u32bit,
+ RandomNumberGenerator& rng);
+ bool verify(const MemoryRegion<byte>&, const MemoryRegion<byte>&,
+ u32bit) throw();
+
+ const u32bit SALT_SIZE;
+ HashFunction* hash;
+ const MGF* mgf;
+ };
+
+}
+
+#endif
diff --git a/src/pk_pad/emsa4/modinfo.txt b/src/pk_pad/emsa4/modinfo.txt
new file mode 100644
index 000000000..39a34c619
--- /dev/null
+++ b/src/pk_pad/emsa4/modinfo.txt
@@ -0,0 +1,10 @@
+realname "EMSA4"
+
+define EMSA4
+
+load_on auto
+
+<add>
+emsa4.h
+emsa4.cpp
+</add>