Use size_t for BufferedComputation::add_data

64 files changed, 216 insertions, 209 deletions

diff --git a/src/checksum/adler32/adler32.cpp b/src/checksum/adler32/adler32.cpp
index 09e42b8db..62589733f 100644
--- a/src/checksum/adler32/adler32.cpp
+++ b/src/checksum/adler32/adler32.cpp
@@ -55,9 +55,9 @@ void adler32_update(const byte input[], size_t length,
 /*
 * Update an Adler32 Checksum
 */
-void Adler32::add_data(const byte input[], u32bit length)
+void Adler32::add_data(const byte input[], size_t length)
    {
-   const u32bit PROCESS_AMOUNT = 5552;
+   const size_t PROCESS_AMOUNT = 5552;
 
    while(length >= PROCESS_AMOUNT)
       {
diff --git a/src/checksum/adler32/adler32.h b/src/checksum/adler32/adler32.h
index 4993e601b..3a2441ad3 100644
--- a/src/checksum/adler32/adler32.h
+++ b/src/checksum/adler32/adler32.h
@@ -24,7 +24,7 @@ class BOTAN_DLL Adler32 : public HashFunction
       Adler32() : HashFunction(4) { clear(); }
       ~Adler32() { clear(); }
    private:
-      void add_data(const byte[], u32bit);
+      void add_data(const byte[], size_t);
       void final_result(byte[]);
       u16bit S1, S2;
    };
diff --git a/src/checksum/crc24/crc24.cpp b/src/checksum/crc24/crc24.cpp
index 5441020f5..d641047a2 100644
--- a/src/checksum/crc24/crc24.cpp
+++ b/src/checksum/crc24/crc24.cpp
@@ -13,7 +13,7 @@ namespace Botan {
 /*
 * Update a CRC24 Checksum
 */
-void CRC24::add_data(const byte input[], u32bit length)
+void CRC24::add_data(const byte input[], size_t length)
    {
    const u32bit TABLE[256] = {
       0x00000000, 0x00864CFB, 0x008AD50D, 0x000C99F6, 0x0093E6E1, 0x0015AA1A,
@@ -82,8 +82,10 @@ void CRC24::add_data(const byte input[], u32bit length)
       input += 16;
       length -= 16;
       }
-   for(u32bit j = 0; j != length; ++j)
-      tmp = TABLE[((tmp >> 16) ^ input[j]) & 0xFF] ^ (tmp << 8);
+
+   for(size_t i = 0; i != length; ++i)
+      tmp = TABLE[((tmp >> 16) ^ input[i]) & 0xFF] ^ (tmp << 8);
+
    crc = tmp;
    }
 
@@ -92,8 +94,8 @@ void CRC24::add_data(const byte input[], u32bit length)
 */
 void CRC24::final_result(byte output[])
    {
-   for(u32bit j = 0; j != 3; ++j)
-      output[j] = get_byte(j+1, crc);
+   for(size_t i = 0; i != 3; ++i)
+      output[i] = get_byte(i+1, crc);
    clear();
    }
 
diff --git a/src/checksum/crc24/crc24.h b/src/checksum/crc24/crc24.h
index 2fc5af2ff..f9786dfa4 100644
--- a/src/checksum/crc24/crc24.h
+++ b/src/checksum/crc24/crc24.h
@@ -24,7 +24,7 @@ class BOTAN_DLL CRC24 : public HashFunction
       CRC24() : HashFunction(3) { clear(); }
       ~CRC24() { clear(); }
    private:
-      void add_data(const byte[], u32bit);
+      void add_data(const byte[], size_t);
       void final_result(byte[]);
       u32bit crc;
    };
diff --git a/src/checksum/crc32/crc32.cpp b/src/checksum/crc32/crc32.cpp
index 42462096f..574e13bae 100644
--- a/src/checksum/crc32/crc32.cpp
+++ b/src/checksum/crc32/crc32.cpp
@@ -13,7 +13,7 @@ namespace Botan {
 /*
 * Update a CRC32 Checksum
 */
-void CRC32::add_data(const byte input[], u32bit length)
+void CRC32::add_data(const byte input[], size_t length)
    {
    const u32bit TABLE[256] = {
       0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F,
@@ -83,8 +83,8 @@ void CRC32::add_data(const byte input[], u32bit length)
       length -= 16;
       }
 
-   for(u32bit j = 0; j != length; ++j)
-      tmp = TABLE[(tmp ^ input[j]) & 0xFF] ^ (tmp >> 8);
+   for(size_t i = 0; i != length; ++i)
+      tmp = TABLE[(tmp ^ input[i]) & 0xFF] ^ (tmp >> 8);
 
    crc = tmp;
    }
diff --git a/src/checksum/crc32/crc32.h b/src/checksum/crc32/crc32.h
index 9fd69670d..aa8c366e5 100644
--- a/src/checksum/crc32/crc32.h
+++ b/src/checksum/crc32/crc32.h
@@ -24,7 +24,7 @@ class BOTAN_DLL CRC32 : public HashFunction
       CRC32() : HashFunction(4) { clear(); }
       ~CRC32() { clear(); }
    private:
-      void add_data(const byte[], u32bit);
+      void add_data(const byte[], size_t);
       void final_result(byte[]);
       u32bit crc;
    };
diff --git a/src/engine/openssl/ossl_md.cpp b/src/engine/openssl/ossl_md.cpp
index f41e0f950..b2707eec4 100644
--- a/src/engine/openssl/ossl_md.cpp
+++ b/src/engine/openssl/ossl_md.cpp
@@ -24,7 +24,7 @@ class EVP_HashFunction : public HashFunction
       EVP_HashFunction(const EVP_MD*, const std::string&);
       ~EVP_HashFunction();
    private:
-      void add_data(const byte[], u32bit);
+      void add_data(const byte[], size_t);
       void final_result(byte[]);
 
       std::string algo_name;
@@ -34,7 +34,7 @@ class EVP_HashFunction : public HashFunction
 /*
 * Update an EVP Hash Calculation
 */
-void EVP_HashFunction::add_data(const byte input[], u32bit length)
+void EVP_HashFunction::add_data(const byte input[], size_t length)
    {
    EVP_DigestUpdate(&md, input, length);
    }
diff --git a/src/hash/bmw/bmw_512.cpp b/src/hash/bmw/bmw_512.cpp
index cfa0eee2c..a69d23bff 100644
--- a/src/hash/bmw/bmw_512.cpp
+++ b/src/hash/bmw/bmw_512.cpp
@@ -43,9 +43,9 @@ inline u64bit S4(u64bit X)
 */
 void BMW_512_compress(u64bit H[16], const u64bit M[16], u64bit Q[32])
    {
-   const u32bit EXPAND_1_ROUNDS = 2;
+   const size_t EXPAND_1_ROUNDS = 2;
 
-   for(u32bit i = 0; i != 16; ++i)
+   for(size_t i = 0; i != 16; ++i)
       Q[i] = H[i] ^ M[i];
 
    Q[16] = Q[ 5] - Q[ 7] + Q[10] + Q[13] + Q[14];
@@ -82,7 +82,7 @@ void BMW_512_compress(u64bit H[16], const u64bit M[16], u64bit Q[32])
    Q[14] = S4(Q[30]) + H[15];
    Q[15] = S0(Q[31]) + H[ 0];
 
-   for(u32bit i = 16; i != 16 + EXPAND_1_ROUNDS; ++i)
+   for(size_t i = 16; i != 16 + EXPAND_1_ROUNDS; ++i)
       {
       Q[i] = S1(Q[i-16]) + S2(Q[i-15]) + S3(Q[i-14]) + S0(Q[i-13]) +
              S1(Q[i-12]) + S2(Q[i-11]) + S3(Q[i-10]) + S0(Q[i- 9]) +
@@ -94,7 +94,7 @@ void BMW_512_compress(u64bit H[16], const u64bit M[16], u64bit Q[32])
                (0x0555555555555555 * i)) ^ H[(i-16+7)%16]);
       }
 
-   for(u32bit i = 16 + EXPAND_1_ROUNDS; i != 32; ++i)
+   for(size_t i = 16 + EXPAND_1_ROUNDS; i != 32; ++i)
       {
       Q[i] = Q[i-16] + rotate_left(Q[i-15],  5) +
              Q[i-14] + rotate_left(Q[i-13], 11) +
@@ -139,9 +139,9 @@ void BMW_512_compress(u64bit H[16], const u64bit M[16], u64bit Q[32])
 
 }
 
-void BMW_512::compress_n(const byte input[], u32bit blocks)
+void BMW_512::compress_n(const byte input[], size_t blocks)
    {
-   for(u32bit i = 0; i != blocks; ++i)
+   for(size_t i = 0; i != blocks; ++i)
       {
       load_le(&M[0], input, M.size());
 
@@ -168,7 +168,7 @@ void BMW_512::copy_out(byte output[])
 
    BMW_512_compress(final, &H[0], &Q[0]);
 
-   for(u32bit i = 0; i != OUTPUT_LENGTH; i += 8)
+   for(size_t i = 0; i != OUTPUT_LENGTH; i += 8)
       store_le(final[8 + i/8], output + i);
    }
 
diff --git a/src/hash/bmw/bmw_512.h b/src/hash/bmw/bmw_512.h
index b1eaa6874..aa527c142 100644
--- a/src/hash/bmw/bmw_512.h
+++ b/src/hash/bmw/bmw_512.h
@@ -25,7 +25,7 @@ class BOTAN_DLL BMW_512 : public MDx_HashFunction
       BMW_512() : MDx_HashFunction(64, 128, false, true), H(16), M(16), Q(32)
          { clear(); }
    private:
-      void compress_n(const byte input[], u32bit blocks);
+      void compress_n(const byte input[], size_t blocks);
       void copy_out(byte output[]);
 
       SecureVector<u64bit> H, M, Q;
diff --git a/src/hash/comb4p/comb4p.cpp b/src/hash/comb4p/comb4p.cpp
index ecbdc4671..681e20685 100644
--- a/src/hash/comb4p/comb4p.cpp
+++ b/src/hash/comb4p/comb4p.cpp
@@ -13,7 +13,7 @@ namespace Botan {
 
 namespace {
 
-u32bit comb4p_block_size(const HashFunction* h1,
+size_t comb4p_block_size(const HashFunction* h1,
                          const HashFunction* h2)
    {
    if(h1->HASH_BLOCK_SIZE == h2->HASH_BLOCK_SIZE)
@@ -73,7 +73,7 @@ void Comb4P::clear()
    hash2->update(0);
    }
 
-void Comb4P::add_data(const byte input[], u32bit length)
+void Comb4P::add_data(const byte input[], size_t length)
    {
    hash1->update(input, length);
    hash2->update(input, length);
diff --git a/src/hash/comb4p/comb4p.h b/src/hash/comb4p/comb4p.h
index 550b70b14..b09f2976b 100644
--- a/src/hash/comb4p/comb4p.h
+++ b/src/hash/comb4p/comb4p.h
@@ -39,7 +39,7 @@ class BOTAN_DLL Comb4P : public HashFunction
 
       void clear();
    private:
-      void add_data(const byte input[], u32bit length);
+      void add_data(const byte input[], size_t length);
       void final_result(byte out[]);
 
       HashFunction* hash1;
diff --git a/src/hash/gost_3411/gost_3411.cpp b/src/hash/gost_3411/gost_3411.cpp
index b460de29c..dbd6335bd 100644
--- a/src/hash/gost_3411/gost_3411.cpp
+++ b/src/hash/gost_3411/gost_3411.cpp
@@ -38,7 +38,7 @@ void GOST_34_11::clear()
 /**
 * Hash additional inputs
 */
-void GOST_34_11::add_data(const byte input[], u32bit length)
+void GOST_34_11::add_data(const byte input[], size_t length)
    {
    count += length;
 
@@ -55,8 +55,8 @@ void GOST_34_11::add_data(const byte input[], u32bit length)
          }
       }
 
-   const u32bit full_blocks = length / HASH_BLOCK_SIZE;
-   const u32bit remaining   = length % HASH_BLOCK_SIZE;
+   const size_t full_blocks = length / HASH_BLOCK_SIZE;
+   const size_t remaining   = length % HASH_BLOCK_SIZE;
 
    if(full_blocks)
       compress_n(input, full_blocks);
@@ -68,11 +68,11 @@ void GOST_34_11::add_data(const byte input[], u32bit length)
 /**
 * The GOST 34.11 compression function
 */
-void GOST_34_11::compress_n(const byte input[], u32bit blocks)
+void GOST_34_11::compress_n(const byte input[], size_t blocks)
    {
-   for(u32bit i = 0; i != blocks; ++i)
+   for(size_t i = 0; i != blocks; ++i)
       {
-      for(u32bit j = 0, carry = 0; j != 32; ++j)
+      for(size_t j = 0, carry = 0; j != 32; ++j)
          {
          u16bit s = sum[j] + input[32*i+j] + carry;
          carry = get_byte(0, s);
@@ -85,7 +85,7 @@ void GOST_34_11::compress_n(const byte input[], u32bit blocks)
       load_be(U, &hash[0], 4);
       load_be(V, input + 32*i, 4);
 
-      for(u32bit j = 0; j != 4; ++j)
+      for(size_t j = 0; j != 4; ++j)
          {
          byte key[32] = { 0 };
 
diff --git a/src/hash/gost_3411/gost_3411.h b/src/hash/gost_3411/gost_3411.h
index 5d26e8557..693b900d2 100644
--- a/src/hash/gost_3411/gost_3411.h
+++ b/src/hash/gost_3411/gost_3411.h
@@ -25,9 +25,9 @@ class BOTAN_DLL GOST_34_11 : public HashFunction
 
       GOST_34_11();
    private:
-      void compress_n(const byte input[], u32bit blocks);
+      void compress_n(const byte input[], size_t blocks);
 
-      void add_data(const byte[], u32bit);
+      void add_data(const byte[], size_t);
       void final_result(byte[]);
 
       GOST_28147_89 cipher;
diff --git a/src/hash/has160/has160.cpp b/src/hash/has160/has160.cpp
index 5786ae0ee..4f8db53f7 100644
--- a/src/hash/has160/has160.cpp
+++ b/src/hash/has160/has160.cpp
@@ -58,14 +58,14 @@ inline void F4(u32bit A, u32bit& B, u32bit C, u32bit D, u32bit& E,
 /*
 * HAS-160 Compression Function
 */
-void HAS_160::compress_n(const byte input[], u32bit blocks)
+void HAS_160::compress_n(const byte input[], size_t blocks)
    {
    using namespace HAS_160_F;
 
    u32bit A = digest[0], B = digest[1], C = digest[2],
           D = digest[3], E = digest[4];
 
-   for(u32bit i = 0; i != blocks; ++i)
+   for(size_t i = 0; i != blocks; ++i)
       {
       load_le(&X[0], input, 16);
 
@@ -144,8 +144,8 @@ void HAS_160::compress_n(const byte input[], u32bit blocks)
 */
 void HAS_160::copy_out(byte output[])
    {
-   for(u32bit j = 0; j != OUTPUT_LENGTH; j += 4)
-      store_le(digest[j/4], output + j);
+   for(size_t i = 0; i != OUTPUT_LENGTH; i += 4)
+      store_le(digest[i/4], output + i);
    }
 
 /*
diff --git a/src/hash/has160/has160.h b/src/hash/has160/has160.h
index 7cff320b8..83ed5ab56 100644
--- a/src/hash/has160/has160.h
+++ b/src/hash/has160/has160.h
@@ -26,7 +26,7 @@ class BOTAN_DLL HAS_160 : public MDx_HashFunction
       HAS_160() : MDx_HashFunction(20, 64, false, true), X(20), digest(5)
          { clear(); }
    private:
-      void compress_n(const byte[], u32bit blocks);
+      void compress_n(const byte[], size_t blocks);
       void copy_out(byte[]);
 
       SecureVector<u32bit> X, digest;
diff --git a/src/hash/md2/md2.cpp b/src/hash/md2/md2.cpp
index 462e43b25..5d8f5f15c 100644
--- a/src/hash/md2/md2.cpp
+++ b/src/hash/md2/md2.cpp
@@ -42,28 +42,31 @@ void MD2::hash(const byte input[])
    X.copy(16, input, HASH_BLOCK_SIZE);
    xor_buf(&X[32], &X[0], &X[16], HASH_BLOCK_SIZE);
    byte T = 0;
-   for(u32bit j = 0; j != 18; ++j)
+
+   for(size_t i = 0; i != 18; ++i)
       {
-      for(u32bit k = 0; k != 48; k += 8)
+      for(size_t k = 0; k != 48; k += 8)
          {
          T = X[k  ] ^= SBOX[T]; T = X[k+1] ^= SBOX[T];
          T = X[k+2] ^= SBOX[T]; T = X[k+3] ^= SBOX[T];
          T = X[k+4] ^= SBOX[T]; T = X[k+5] ^= SBOX[T];
          T = X[k+6] ^= SBOX[T]; T = X[k+7] ^= SBOX[T];
          }
-      T += j;
+      T += i;
       }
+
    T = checksum[15];
-   for(u32bit j = 0; j != HASH_BLOCK_SIZE; ++j)
-      T = checksum[j] ^= SBOX[input[j] ^ T];
+   for(size_t i = 0; i != HASH_BLOCK_SIZE; ++i)
+      T = checksum[i] ^= SBOX[input[i] ^ T];
    }
 
 /**
 * Update the hash
 */
-void MD2::add_data(const byte input[], u32bit length)
+void MD2::add_data(const byte input[], size_t length)
    {
    buffer.copy(position, input, length);
+
    if(position + length >= HASH_BLOCK_SIZE)
       {
       hash(&buffer[0]);
@@ -86,8 +89,9 @@ void MD2::add_data(const byte input[], u32bit length)
 */
 void MD2::final_result(byte output[])
    {
-   for(u32bit j = position; j != HASH_BLOCK_SIZE; ++j)
-      buffer[j] = static_cast<byte>(HASH_BLOCK_SIZE - position);
+   for(size_t i = position; i != HASH_BLOCK_SIZE; ++i)
+      buffer[i] = static_cast<byte>(HASH_BLOCK_SIZE - position);
+
    hash(&buffer[0]);
    hash(&checksum[0]);
    copy_mem(output, &X[0], OUTPUT_LENGTH);
diff --git a/src/hash/md2/md2.h b/src/hash/md2/md2.h
index b25d5f410..86e0d3c80 100644
--- a/src/hash/md2/md2.h
+++ b/src/hash/md2/md2.h
@@ -25,12 +25,12 @@ class BOTAN_DLL MD2 : public HashFunction
       MD2() : HashFunction(16, 16), X(48), checksum(16), buffer(16)
          { clear(); }
    private:
-      void add_data(const byte[], u32bit);
+      void add_data(const byte[], size_t);
       void hash(const byte[]);
       void final_result(byte[]);
 
       SecureVector<byte> X, checksum, buffer;
-      u32bit position;
+      size_t position;
    };
 
 }
diff --git a/src/hash/md4/md4.cpp b/src/hash/md4/md4.cpp
index 326ca8eba..3f9259deb 100644
--- a/src/hash/md4/md4.cpp
+++ b/src/hash/md4/md4.cpp
@@ -45,11 +45,11 @@ inline void HH(u32bit& A, u32bit B, u32bit C, u32bit D, u32bit M, byte S)
 /*
 * MD4 Compression Function
 */
-void MD4::compress_n(const byte input[], u32bit blocks)
+void MD4::compress_n(const byte input[], size_t blocks)
    {
    u32bit A = digest[0], B = digest[1], C = digest[2], D = digest[3];
 
-   for(u32bit i = 0; i != blocks; ++i)
+   for(size_t i = 0; i != blocks; ++i)
       {
       load_le(&M[0], input, M.size());
 
@@ -94,8 +94,8 @@ void MD4::compress_n(const byte input[], u32bit blocks)
 */
 void MD4::copy_out(byte output[])
    {
-   for(u32bit j = 0; j != OUTPUT_LENGTH; j += 4)
-      store_le(digest[j/4], output + j);
+   for(size_t i = 0; i != OUTPUT_LENGTH; i += 4)
+      store_le(digest[i/4], output + i);
    }
 
 /*
diff --git a/src/hash/md4/md4.h b/src/hash/md4/md4.h
index 44081e635..07467fdfc 100644
--- a/src/hash/md4/md4.h
+++ b/src/hash/md4/md4.h
@@ -25,7 +25,7 @@ class BOTAN_DLL MD4 : public MDx_HashFunction
       MD4() : MDx_HashFunction(16, 64, false, true), M(16), digest(4)
          { clear(); }
    protected:
-      void compress_n(const byte input[], u32bit blocks);
+      void compress_n(const byte input[], size_t blocks);
       void copy_out(byte[]);
 
       SecureVector<u32bit> M, digest;
diff --git a/src/hash/md4_ia32/md4_ia32.cpp b/src/hash/md4_ia32/md4_ia32.cpp
index 8a60d8f0e..8983995fc 100644
--- a/src/hash/md4_ia32/md4_ia32.cpp
+++ b/src/hash/md4_ia32/md4_ia32.cpp
@@ -14,9 +14,9 @@ extern "C" void botan_md4_ia32_compress(u32bit[4], const byte[64], u32bit[16]);
 /*
 * MD4 Compression Function
 */
-void MD4_IA32::compress_n(const byte input[], u32bit blocks)
+void MD4_IA32::compress_n(const byte input[], size_t blocks)
    {
-   for(u32bit i = 0; i != blocks; ++i)
+   for(size_t i = 0; i != blocks; ++i)
       {
       botan_md4_ia32_compress(digest, input, M);
       input += HASH_BLOCK_SIZE;
diff --git a/src/hash/md4_ia32/md4_ia32.h b/src/hash/md4_ia32/md4_ia32.h
index ef8060d3f..4bb8f1add 100644
--- a/src/hash/md4_ia32/md4_ia32.h
+++ b/src/hash/md4_ia32/md4_ia32.h
@@ -20,7 +20,7 @@ class BOTAN_DLL MD4_IA32 : public MD4
    public:
       HashFunction* clone() const { return new MD4_IA32; }
    private:
-      void compress_n(const byte[], u32bit blocks);
+      void compress_n(const byte[], size_t blocks);
    };
 
 }
diff --git a/src/hash/md5/md5.cpp b/src/hash/md5/md5.cpp
index b1745b944..69ab89e63 100644
--- a/src/hash/md5/md5.cpp
+++ b/src/hash/md5/md5.cpp
@@ -58,11 +58,11 @@ inline void II(u32bit& A, u32bit B, u32bit C, u32bit D, u32bit msg,
 /*
 * MD5 Compression Function
 */
-void MD5::compress_n(const byte input[], u32bit blocks)
+void MD5::compress_n(const byte input[], size_t blocks)
    {
    u32bit A = digest[0], B = digest[1], C = digest[2], D = digest[3];
 
-   for(u32bit i = 0; i != blocks; ++i)
+   for(size_t i = 0; i != blocks; ++i)
       {
       load_le(&M[0], input, M.size());
 
@@ -116,8 +116,8 @@ void MD5::compress_n(const byte input[], u32bit blocks)
 */
 void MD5::copy_out(byte output[])
    {
-   for(u32bit j = 0; j != OUTPUT_LENGTH; j += 4)
-      store_le(digest[j/4], output + j);
+   for(size_t i = 0; i != OUTPUT_LENGTH; i += 4)
+      store_le(digest[i/4], output + i);
    }
 
 /*
diff --git a/src/hash/md5/md5.h b/src/hash/md5/md5.h
index 732ec026d..f79a3ec65 100644
--- a/src/hash/md5/md5.h
+++ b/src/hash/md5/md5.h
@@ -25,7 +25,7 @@ class BOTAN_DLL MD5 : public MDx_HashFunction
       MD5() : MDx_HashFunction(16, 64, false, true), M(16), digest(4)
          { clear(); }
    protected:
-      void compress_n(const byte[], u32bit blocks);
+      void compress_n(const byte[], size_t blocks);
       void copy_out(byte[]);
 
       SecureVector<u32bit> M, digest;
diff --git a/src/hash/md5_ia32/md5_ia32.cpp b/src/hash/md5_ia32/md5_ia32.cpp
index affd0b8f7..66a18e6f5 100644
--- a/src/hash/md5_ia32/md5_ia32.cpp
+++ b/src/hash/md5_ia32/md5_ia32.cpp
@@ -19,9 +19,9 @@ void botan_md5_ia32_compress(u32bit[4], const byte[64], u32bit[16]);
 /*
 * MD5 Compression Function
 */
-void MD5_IA32::compress_n(const byte input[], u32bit blocks)
+void MD5_IA32::compress_n(const byte input[], size_t blocks)
    {
-   for(u32bit i = 0; i != blocks; ++i)
+   for(size_t i = 0; i != blocks; ++i)
       {
       botan_md5_ia32_compress(digest, input, M);
       input += HASH_BLOCK_SIZE;
diff --git a/src/hash/md5_ia32/md5_ia32.h b/src/hash/md5_ia32/md5_ia32.h
index b65490760..bf4b4c505 100644
--- a/src/hash/md5_ia32/md5_ia32.h
+++ b/src/hash/md5_ia32/md5_ia32.h
@@ -20,7 +20,7 @@ class BOTAN_DLL MD5_IA32 : public MD5
    public:
       HashFunction* clone() const { return new MD5_IA32; }
    private:
-      void compress_n(const byte[], u32bit blocks);
+      void compress_n(const byte[], size_t blocks);
    };
 
 }
diff --git a/src/hash/mdx_hash/mdx_hash.cpp b/src/hash/mdx_hash/mdx_hash.cpp
index 560832542..cea66044b 100644
--- a/src/hash/mdx_hash/mdx_hash.cpp
+++ b/src/hash/mdx_hash/mdx_hash.cpp
@@ -14,9 +14,9 @@ namespace Botan {
 /*
 * MDx_HashFunction Constructor
 */
-MDx_HashFunction::MDx_HashFunction(u32bit hash_len, u32bit block_len,
+MDx_HashFunction::MDx_HashFunction(size_t hash_len, size_t block_len,
                                    bool byte_end, bool bit_end,
-                                   u32bit cnt_size) :
+                                   size_t cnt_size) :
    HashFunction(hash_len, block_len), buffer(block_len),
    BIG_BYTE_ENDIAN(byte_end), BIG_BIT_ENDIAN(bit_end), COUNT_SIZE(cnt_size)
    {
@@ -37,7 +37,7 @@ void MDx_HashFunction::clear()
 /*
 * Update the hash
 */
-void MDx_HashFunction::add_data(const byte input[], u32bit length)
+void MDx_HashFunction::add_data(const byte input[], size_t length)
    {
    count += length;
 
@@ -54,8 +54,8 @@ void MDx_HashFunction::add_data(const byte input[], u32bit length)
          }
       }
 
-   const u32bit full_blocks = length / HASH_BLOCK_SIZE;
-   const u32bit remaining   = length % HASH_BLOCK_SIZE;
+   const size_t full_blocks = length / HASH_BLOCK_SIZE;
+   const size_t remaining   = length % HASH_BLOCK_SIZE;
 
    if(full_blocks)
       compress_n(input, full_blocks);
@@ -70,8 +70,8 @@ void MDx_HashFunction::add_data(const byte input[], u32bit length)
 void MDx_HashFunction::final_result(byte output[])
    {
    buffer[position] = (BIG_BIT_ENDIAN ? 0x80 : 0x01);
-   for(u32bit j = position+1; j != HASH_BLOCK_SIZE; ++j)
-      buffer[j] = 0;
+   for(size_t i = position+1; i != HASH_BLOCK_SIZE; ++i)
+      buffer[i] = 0;
 
    if(position >= HASH_BLOCK_SIZE - COUNT_SIZE)
       {
diff --git a/src/hash/mdx_hash/mdx_hash.h b/src/hash/mdx_hash/mdx_hash.h
index 087c7fc46..6603f54bc 100644
--- a/src/hash/mdx_hash/mdx_hash.h
+++ b/src/hash/mdx_hash/mdx_hash.h
@@ -25,15 +25,15 @@ class BOTAN_DLL MDx_HashFunction : public HashFunction
       * @param big_bit_endian specifies if the hash uses big-endian bits
       * @param counter_size specifies the size of the counter var in bytes
       */
-      MDx_HashFunction(u32bit hash_length,
-                       u32bit block_length,
+      MDx_HashFunction(size_t hash_length,
+                       size_t block_length,
                        bool big_byte_endian,
                        bool big_bit_endian,
-                       u32bit counter_size = 8);
+                       size_t counter_size = 8);
 
       virtual ~MDx_HashFunction() {}
    protected:
-      void add_data(const byte input[], u32bit length);
+      void add_data(const byte input[], size_t length);
       void final_result(byte output[]);
 
       /**
@@ -41,7 +41,7 @@ class BOTAN_DLL MDx_HashFunction : public HashFunction
       * @param blocks the input
       * @param block_n the number of blocks
       */
-      virtual void compress_n(const byte blocks[], u32bit block_n) = 0;
+      virtual void compress_n(const byte blocks[], size_t block_n) = 0;
 
       void clear();
 
@@ -59,7 +59,7 @@ class BOTAN_DLL MDx_HashFunction : public HashFunction
    private:
       SecureVector<byte> buffer;
       u64bit count;
-      u32bit position;
+      size_t position;
 
       const bool BIG_BYTE_ENDIAN, BIG_BIT_ENDIAN;
       const u32bit COUNT_SIZE;
diff --git a/src/hash/par_hash/par_hash.cpp b/src/hash/par_hash/par_hash.cpp
index 0ba3f5a4f..794166327 100644
--- a/src/hash/par_hash/par_hash.cpp
+++ b/src/hash/par_hash/par_hash.cpp
@@ -14,12 +14,12 @@ namespace {
 /*
 * Return the sum of the hash sizes
 */
-u32bit sum_of_hash_lengths(const std::vector<HashFunction*>& hashes)
+size_t sum_of_hash_lengths(const std::vector<HashFunction*>& hashes)
    {
-   u32bit sum = 0;
+   size_t sum = 0;
 
-   for(u32bit j = 0; j != hashes.size(); ++j)
-      sum += hashes[j]->OUTPUT_LENGTH;
+   for(size_t i = 0; i != hashes.size(); ++i)
+      sum += hashes[i]->OUTPUT_LENGTH;
 
    return sum;
    }
@@ -29,10 +29,10 @@ u32bit sum_of_hash_lengths(const std::vector<HashFunction*>& hashes)
 /*
 * Update the hash
 */
-void Parallel::add_data(const byte input[], u32bit length)
+void Parallel::add_data(const byte input[], size_t length)
    {
-   for(u32bit j = 0; j != hashes.size(); ++j)
-      hashes[j]->update(input, length);
+   for(size_t i = 0; i != hashes.size(); ++i)
+      hashes[i]->update(input, length);
    }
 
 /*
@@ -40,11 +40,11 @@ void Parallel::add_data(const byte input[], u32bit length)
 */
 void Parallel::final_result(byte hash[])
    {
-   u32bit offset = 0;
-   for(u32bit j = 0; j != hashes.size(); ++j)
+   size_t offset = 0;
+   for(size_t i = 0; i != hashes.size(); ++i)
       {
-      hashes[j]->final(hash + offset);
-      offset += hashes[j]->OUTPUT_LENGTH;
+      hashes[i]->final(hash + offset);
+      offset += hashes[i]->OUTPUT_LENGTH;
       }
    }
 
@@ -54,11 +54,11 @@ void Parallel::final_result(byte hash[])
 std::string Parallel::name() const
    {
    std::string hash_names;
-   for(u32bit j = 0; j != hashes.size(); ++j)
+   for(size_t i = 0; i != hashes.size(); ++i)
       {
-      if(j)
+      if(i)
          hash_names += ',';
-      hash_names += hashes[j]->name();
+      hash_names += hashes[i]->name();
       }
    return "Parallel(" + hash_names + ")";
    }
@@ -69,8 +69,8 @@ std::string Parallel::name() const
 HashFunction* Parallel::clone() const
    {
    std::vector<HashFunction*> hash_copies;
-   for(u32bit j = 0; j != hashes.size(); ++j)
-      hash_copies.push_back(hashes[j]->clone());
+   for(size_t i = 0; i != hashes.size(); ++i)
+      hash_copies.push_back(hashes[i]->clone());
    return new Parallel(hash_copies);
    }
 
@@ -79,8 +79,8 @@ HashFunction* Parallel::clone() const
 */
 void Parallel::clear()
    {
-   for(u32bit j = 0; j != hashes.size(); ++j)
-      hashes[j]->clear();
+   for(size_t i = 0; i != hashes.size(); ++i)
+      hashes[i]->clear();
    }
 
 /*
@@ -96,8 +96,8 @@ Parallel::Parallel(const std::vector<HashFunction*>& hash_in) :
 */
 Parallel::~Parallel()
    {
-   for(u32bit j = 0; j != hashes.size(); ++j)
-      delete hashes[j];
+   for(size_t i = 0; i != hashes.size(); ++i)
+      delete hashes[i];
    }
 
 }
diff --git a/src/hash/par_hash/par_hash.h b/src/hash/par_hash/par_hash.h
index d82a74a19..35154dde4 100644
--- a/src/hash/par_hash/par_hash.h
+++ b/src/hash/par_hash/par_hash.h
@@ -29,7 +29,7 @@ class BOTAN_DLL Parallel : public HashFunction
       Parallel(const std::vector<HashFunction*>& hashes);
       ~Parallel();
    private:
-      void add_data(const byte[], u32bit);
+      void add_data(const byte[], size_t);
       void final_result(byte[]);
       std::vector<HashFunction*> hashes;
    };
diff --git a/src/hash/rmd128/rmd128.cpp b/src/hash/rmd128/rmd128.cpp
index 3e7eb9143..61737a4a0 100644
--- a/src/hash/rmd128/rmd128.cpp
+++ b/src/hash/rmd128/rmd128.cpp
@@ -58,7 +58,7 @@ inline void F4(u32bit& A, u32bit B, u32bit C, u32bit D,
 /*
 * RIPEMD-128 Compression Function
 */
-void RIPEMD_128::compress_n(const byte input[], u32bit blocks)
+void RIPEMD_128::compress_n(const byte input[], size_t blocks)
    {
    using namespace RIPEMD_128_F;
 
@@ -66,7 +66,7 @@ void RIPEMD_128::compress_n(const byte input[], u32bit blocks)
                 MAGIC4 = 0x8F1BBCDC, MAGIC5 = 0x50A28BE6,
                 MAGIC6 = 0x5C4DD124, MAGIC7 = 0x6D703EF3;
 
-   for(u32bit i = 0; i != blocks; ++i)
+   for(size_t i = 0; i != blocks; ++i)
       {
       load_le(&M[0], input, M.size());
 
@@ -156,8 +156,8 @@ void RIPEMD_128::compress_n(const byte input[], u32bit blocks)
 */
 void RIPEMD_128::copy_out(byte output[])
    {
-   for(u32bit j = 0; j != OUTPUT_LENGTH; j += 4)
-      store_le(digest[j/4], output + j);
+   for(size_t i = 0; i != OUTPUT_LENGTH; i += 4)
+      store_le(digest[i/4], output + i);
    }
 
 /*
diff --git a/src/hash/rmd128/rmd128.h b/src/hash/rmd128/rmd128.h
index 23272c622..faead3245 100644
--- a/src/hash/rmd128/rmd128.h
+++ b/src/hash/rmd128/rmd128.h
@@ -25,7 +25,7 @@ class BOTAN_DLL RIPEMD_128 : public MDx_HashFunction
       RIPEMD_128() : MDx_HashFunction(16, 64, false, true), M(16), digest(4)
          { clear(); }
    private:
-      void compress_n(const byte[], u32bit blocks);
+      void compress_n(const byte[], size_t blocks);
       void copy_out(byte[]);
 
       SecureVector<u32bit> M, digest;
diff --git a/src/hash/rmd160/rmd160.cpp b/src/hash/rmd160/rmd160.cpp
index f832d4ec1..255f3f95a 100644
--- a/src/hash/rmd160/rmd160.cpp
+++ b/src/hash/rmd160/rmd160.cpp
@@ -73,14 +73,14 @@ inline void F5(u32bit& A, u32bit B, u32bit& C, u32bit D, u32bit E,
 /*
 * RIPEMD-160 Compression Function
 */
-void RIPEMD_160::compress_n(const byte input[], u32bit blocks)
+void RIPEMD_160::compress_n(const byte input[], size_t blocks)
    {
    const u32bit MAGIC2 = 0x5A827999, MAGIC3 = 0x6ED9EBA1,
                 MAGIC4 = 0x8F1BBCDC, MAGIC5 = 0xA953FD4E,
                 MAGIC6 = 0x50A28BE6, MAGIC7 = 0x5C4DD124,
                 MAGIC8 = 0x6D703EF3, MAGIC9 = 0x7A6D76E9;
 
-   for(u32bit i = 0; i != blocks; ++i)
+   for(size_t i = 0; i != blocks; ++i)
       {
       load_le(&M[0], input, M.size());
 
@@ -189,8 +189,8 @@ void RIPEMD_160::compress_n(const byte input[], u32bit blocks)
 */
 void RIPEMD_160::copy_out(byte output[])
    {
-   for(u32bit j = 0; j != OUTPUT_LENGTH; j += 4)
-      store_le(digest[j/4], output + j);
+   for(size_t i = 0; i != OUTPUT_LENGTH; i += 4)
+      store_le(digest[i/4], output + i);
    }
 
 /*
diff --git a/src/hash/rmd160/rmd160.h b/src/hash/rmd160/rmd160.h
index 09c995628..69c6b4a40 100644
--- a/src/hash/rmd160/rmd160.h
+++ b/src/hash/rmd160/rmd160.h
@@ -25,7 +25,7 @@ class BOTAN_DLL RIPEMD_160 : public MDx_HashFunction
       RIPEMD_160() : MDx_HashFunction(20, 64, false, true), M(16), digest(5)
          { clear(); }
    private:
-      void compress_n(const byte[], u32bit blocks);
+      void compress_n(const byte[], size_t blocks);
       void copy_out(byte[]);
 
       SecureVector<u32bit> M, digest;
diff --git a/src/hash/sha1/sha160.cpp b/src/hash/sha1/sha160.cpp
index 79348a371..6c98b21d2 100644
--- a/src/hash/sha1/sha160.cpp
+++ b/src/hash/sha1/sha160.cpp
@@ -54,16 +54,16 @@ inline void F4(u32bit A, u32bit& B, u32bit C, u32bit D, u32bit& E, u32bit msg)
 /*
 * SHA-160 Compression Function
 */
-void SHA_160::compress_n(const byte input[], u32bit blocks)
+void SHA_160::compress_n(const byte input[], size_t blocks)
    {
    u32bit A = digest[0], B = digest[1], C = digest[2],
           D = digest[3], E = digest[4];
 
-   for(u32bit i = 0; i != blocks; ++i)
+   for(size_t i = 0; i != blocks; ++i)
       {
       load_be(&W[0], input, 16);
 
-      for(u32bit j = 16; j != 80; j += 8)
+      for(size_t j = 16; j != 80; j += 8)
          {
          W[j  ] = rotate_left((W[j-3] ^ W[j-8] ^ W[j-14] ^ W[j-16]), 1);
          W[j+1] = rotate_left((W[j-2] ^ W[j-7] ^ W[j-13] ^ W[j-15]), 1);
@@ -134,7 +134,7 @@ void SHA_160::compress_n(const byte input[], u32bit blocks)
 */
 void SHA_160::copy_out(byte output[])
    {
-   for(u32bit i = 0; i != OUTPUT_LENGTH; i += 4)
+   for(size_t i = 0; i != OUTPUT_LENGTH; i += 4)
       store_be(digest[i/4], output + i);
    }
 
@@ -164,7 +164,7 @@ SHA_160::SHA_160() :
 /*
 * SHA_160 Constructor
 */
-SHA_160::SHA_160(u32bit W_size) :
+SHA_160::SHA_160(size_t W_size) :
    MDx_HashFunction(20, 64, true, true), digest(5), W(W_size)
    {
    clear();
diff --git a/src/hash/sha1/sha160.h b/src/hash/sha1/sha160.h
index 690aea1d5..d420f8f94 100644
--- a/src/hash/sha1/sha160.h
+++ b/src/hash/sha1/sha160.h
@@ -30,9 +30,9 @@ class BOTAN_DLL SHA_160 : public MDx_HashFunction
       * constraints
       * @param W_size how big to make W
       */
-      SHA_160(u32bit W_size);
+      SHA_160(size_t W_size);
 
-      void compress_n(const byte[], u32bit blocks);
+      void compress_n(const byte[], size_t blocks);
       void copy_out(byte[]);
 
       SecureVector<u32bit> digest;
diff --git a/src/hash/sha1_amd64/sha1_amd64.cpp b/src/hash/sha1_amd64/sha1_amd64.cpp
index 885853182..00b1788cb 100644
--- a/src/hash/sha1_amd64/sha1_amd64.cpp
+++ b/src/hash/sha1_amd64/sha1_amd64.cpp
@@ -19,9 +19,9 @@ void botan_sha160_amd64_compress(u32bit[5], const byte[64], u32bit[80]);
 /*
 * SHA-160 Compression Function
 */
-void SHA_160_AMD64::compress_n(const byte input[], u32bit blocks)
+void SHA_160_AMD64::compress_n(const byte input[], size_t blocks)
    {
-   for(u32bit i = 0; i != blocks; ++i)
+   for(size_t i = 0; i != blocks; ++i)
       {
       botan_sha160_amd64_compress(&digest[0], input, &W[0]);
       input += HASH_BLOCK_SIZE;
diff --git a/src/hash/sha1_amd64/sha1_amd64.h b/src/hash/sha1_amd64/sha1_amd64.h
index 6cf3b0fb7..6b741184d 100644
--- a/src/hash/sha1_amd64/sha1_amd64.h
+++ b/src/hash/sha1_amd64/sha1_amd64.h
@@ -20,7 +20,7 @@ class BOTAN_DLL SHA_160_AMD64 : public SHA_160
    public:
       HashFunction* clone() const { return new SHA_160_AMD64; }
    private:
-      void compress_n(const byte[], u32bit blocks);
+      void compress_n(const byte[], size_t blocks);
    };
 
 }
diff --git a/src/hash/sha1_ia32/sha1_ia32.cpp b/src/hash/sha1_ia32/sha1_ia32.cpp
index 611cc1961..6bc9f31ec 100644
--- a/src/hash/sha1_ia32/sha1_ia32.cpp
+++ b/src/hash/sha1_ia32/sha1_ia32.cpp
@@ -19,9 +19,9 @@ void botan_sha160_ia32_compress(u32bit[5], const byte[64], u32bit[81]);
 /*
 * SHA-160 Compression Function
 */
-void SHA_160_IA32::compress_n(const byte input[], u32bit blocks)
+void SHA_160_IA32::compress_n(const byte input[], size_t blocks)
    {
-   for(u32bit i = 0; i != blocks; ++i)
+   for(size_t i = 0; i != blocks; ++i)
       {
       botan_sha160_ia32_compress(&digest[0], input, &W[0]);
       input += HASH_BLOCK_SIZE;
diff --git a/src/hash/sha1_ia32/sha1_ia32.h b/src/hash/sha1_ia32/sha1_ia32.h
index f579fbc90..5cff03016 100644
--- a/src/hash/sha1_ia32/sha1_ia32.h
+++ b/src/hash/sha1_ia32/sha1_ia32.h
@@ -23,7 +23,7 @@ class BOTAN_DLL SHA_160_IA32 : public SHA_160
       // Note 81 instead of normal 80: IA-32 asm needs an extra temp
       SHA_160_IA32() : SHA_160(81) {}
    private:
-      void compress_n(const byte[], u32bit blocks);
+      void compress_n(const byte[], size_t blocks);
    };
 
 }
diff --git a/src/hash/sha1_sse2/sha1_sse2.cpp b/src/hash/sha1_sse2/sha1_sse2.cpp
index f1102afc5..8270f9ac4 100644
--- a/src/hash/sha1_sse2/sha1_sse2.cpp
+++ b/src/hash/sha1_sse2/sha1_sse2.cpp
@@ -149,7 +149,7 @@ inline void F4(u32bit A, u32bit& B, u32bit C, u32bit D, u32bit& E, u32bit msg)
 /*
 * SHA-160 Compression Function using SSE for message expansion
 */
-void SHA_160_SSE2::compress_n(const byte input_bytes[], u32bit blocks)
+void SHA_160_SSE2::compress_n(const byte input_bytes[], size_t blocks)
    {
    const __m128i K00_19 = _mm_set1_epi32(0x5A827999);
    const __m128i K20_39 = _mm_set1_epi32(0x6ED9EBA1);
@@ -164,7 +164,7 @@ void SHA_160_SSE2::compress_n(const byte input_bytes[], u32bit blocks)
 
    const __m128i* input = reinterpret_cast<const __m128i*>(input_bytes);
 
-   for(u32bit i = 0; i != blocks; ++i)
+   for(size_t i = 0; i != blocks; ++i)
       {
       union v4si {
          u32bit u32[4];
diff --git a/src/hash/sha1_sse2/sha1_sse2.h b/src/hash/sha1_sse2/sha1_sse2.h
index 90935c737..9b7b327f0 100644
--- a/src/hash/sha1_sse2/sha1_sse2.h
+++ b/src/hash/sha1_sse2/sha1_sse2.h
@@ -21,7 +21,7 @@ class BOTAN_DLL SHA_160_SSE2 : public SHA_160
       HashFunction* clone() const { return new SHA_160_SSE2; }
       SHA_160_SSE2() : SHA_160(0) {} // no W needed
    private:
-      void compress_n(const byte[], u32bit blocks);
+      void compress_n(const byte[], size_t blocks);
    };
 
 }
diff --git a/src/hash/sha2_32/sha2_32.cpp b/src/hash/sha2_32/sha2_32.cpp
index acd06061e..6bbf6dec9 100644
--- a/src/hash/sha2_32/sha2_32.cpp
+++ b/src/hash/sha2_32/sha2_32.cpp
@@ -48,17 +48,17 @@ inline void F1(u32bit A, u32bit B, u32bit C, u32bit& D,
 */
 void sha2_32_compress(MemoryRegion<u32bit>& W,
                       MemoryRegion<u32bit>& digest,
-                      const byte input[], u32bit blocks)
+                      const byte input[], size_t blocks)
    {
    u32bit A = digest[0], B = digest[1], C = digest[2],
           D = digest[3], E = digest[4], F = digest[5],
           G = digest[6], H = digest[7];
 
-   for(u32bit i = 0; i != blocks; ++i)
+   for(size_t i = 0; i != blocks; ++i)
       {
       load_be(&W[0], input, 16);
 
-      for(u32bit j = 16; j != 64; j += 8)
+      for(size_t j = 16; j != 64; j += 8)
          {
          W[j  ] = sigma(W[j- 2], 17, 19, 10) + W[j-7] +
                   sigma(W[j-15],  7, 18,  3) + W[j-16];
@@ -161,7 +161,7 @@ void sha2_32_compress(MemoryRegion<u32bit>& W,
 /*
 * SHA-224 compression function
 */
-void SHA_224::compress_n(const byte input[], u32bit blocks)
+void SHA_224::compress_n(const byte input[], size_t blocks)
    {
    sha2_32_compress(W, digest, input, blocks);
    }
@@ -171,8 +171,8 @@ void SHA_224::compress_n(const byte input[], u32bit blocks)
 */
 void SHA_224::copy_out(byte output[])
    {
-   for(u32bit j = 0; j != OUTPUT_LENGTH; j += 4)
-      store_be(digest[j/4], output + j);
+   for(size_t i = 0; i != OUTPUT_LENGTH; i += 4)
+      store_be(digest[i/4], output + i);
    }
 
 /*
@@ -195,7 +195,7 @@ void SHA_224::clear()
 /*
 * SHA-256 compression function
 */
-void SHA_256::compress_n(const byte input[], u32bit blocks)
+void SHA_256::compress_n(const byte input[], size_t blocks)
    {
    sha2_32_compress(W, digest, input, blocks);
    }
@@ -205,8 +205,8 @@ void SHA_256::compress_n(const byte input[], u32bit blocks)
 */
 void SHA_256::copy_out(byte output[])
    {
-   for(u32bit j = 0; j != OUTPUT_LENGTH; j += 4)
-      store_be(digest[j/4], output + j);
+   for(size_t i = 0; i != OUTPUT_LENGTH; i += 4)
+      store_be(digest[i/4], output + i);
    }
 
 /*
diff --git a/src/hash/sha2_32/sha2_32.h b/src/hash/sha2_32/sha2_32.h
index a3e3a6f19..3b95812b8 100644
--- a/src/hash/sha2_32/sha2_32.h
+++ b/src/hash/sha2_32/sha2_32.h
@@ -26,7 +26,7 @@ class BOTAN_DLL SHA_224 : public MDx_HashFunction
       SHA_224() : MDx_HashFunction(28, 64, true, true), W(64), digest(8)
          { clear(); }
    private:
-      void compress_n(const byte[], u32bit blocks);
+      void compress_n(const byte[], size_t blocks);
       void copy_out(byte[]);
 
       SecureVector<u32bit> W, digest;
@@ -45,7 +45,7 @@ class BOTAN_DLL SHA_256 : public MDx_HashFunction
       SHA_256() : MDx_HashFunction(32, 64, true, true), W(64), digest(8)
          { clear(); }
    private:
-      void compress_n(const byte[], u32bit blocks);
+      void compress_n(const byte[], size_t blocks);
       void copy_out(byte[]);
 
       SecureVector<u32bit> W, digest;
diff --git a/src/hash/sha2_64/sha2_64.cpp b/src/hash/sha2_64/sha2_64.cpp
index 5ca78173c..96e672819 100644
--- a/src/hash/sha2_64/sha2_64.cpp
+++ b/src/hash/sha2_64/sha2_64.cpp
@@ -47,17 +47,17 @@ inline u64bit sigma(u64bit X, u32bit rot1, u32bit rot2, u32bit shift)
 */
 void sha2_64_compress(MemoryRegion<u64bit>& W,
                       MemoryRegion<u64bit>& digest,
-                      const byte input[], u32bit blocks)
+                      const byte input[], size_t blocks)
    {
    u64bit A = digest[0], B = digest[1], C = digest[2],
           D = digest[3], E = digest[4], F = digest[5],
           G = digest[6], H = digest[7];
 
-   for(u32bit i = 0; i != blocks; ++i)
+   for(size_t i = 0; i != blocks; ++i)
       {
       load_be(&W[0], input, 16);
 
-      for(u32bit j = 16; j != 80; j += 8)
+      for(size_t j = 16; j != 80; j += 8)
          {
          W[j  ] = sigma(W[j-2], 19, 61, 6) + W[j-7] + sigma(W[j-15], 1, 8, 7) + W[j-16];
          W[j+1] = sigma(W[j-1], 19, 61, 6) + W[j-6] + sigma(W[j-14], 1, 8, 7) + W[j-15];
@@ -168,7 +168,7 @@ void sha2_64_compress(MemoryRegion<u64bit>& W,
 /*
 * SHA-384 compression function
 */
-void SHA_384::compress_n(const byte input[], u32bit blocks)
+void SHA_384::compress_n(const byte input[], size_t blocks)
    {
    sha2_64_compress(W, digest, input, blocks);
    }
@@ -178,8 +178,8 @@ void SHA_384::compress_n(const byte input[], u32bit blocks)
 */
 void SHA_384::copy_out(byte output[])
    {
-   for(u32bit j = 0; j != OUTPUT_LENGTH; j += 8)
-      store_be(digest[j/8], output + j);
+   for(size_t i = 0; i != OUTPUT_LENGTH; i += 8)
+      store_be(digest[i/8], output + i);
    }
 
 /*
@@ -202,7 +202,7 @@ void SHA_384::clear()
 /*
 * SHA-512 compression function
 */
-void SHA_512::compress_n(const byte input[], u32bit blocks)
+void SHA_512::compress_n(const byte input[], size_t blocks)
    {
    sha2_64_compress(W, digest, input, blocks);
    }
@@ -212,8 +212,8 @@ void SHA_512::compress_n(const byte input[], u32bit blocks)
 */
 void SHA_512::copy_out(byte output[])
    {
-   for(u32bit j = 0; j != OUTPUT_LENGTH; j += 8)
-      store_be(digest[j/8], output + j);
+   for(size_t i = 0; i != OUTPUT_LENGTH; i += 8)
+      store_be(digest[i/8], output + i);
    }
 
 /*
diff --git a/src/hash/sha2_64/sha2_64.h b/src/hash/sha2_64/sha2_64.h
index 726712221..59e2c4c83 100644
--- a/src/hash/sha2_64/sha2_64.h
+++ b/src/hash/sha2_64/sha2_64.h
@@ -25,7 +25,7 @@ class BOTAN_DLL SHA_384 : public MDx_HashFunction
       SHA_384() : MDx_HashFunction(48, 128, true, true, 16), W(80), digest(8)
          { clear(); }
    private:
-      void compress_n(const byte[], u32bit blocks);
+      void compress_n(const byte[], size_t blocks);
       void copy_out(byte[]);
 
       SecureVector<u64bit> W, digest;
@@ -43,7 +43,7 @@ class BOTAN_DLL SHA_512 : public MDx_HashFunction
       SHA_512() : MDx_HashFunction(64, 128, true, true, 16), W(80), digest(8)
          { clear(); }
    private:
-      void compress_n(const byte[], u32bit blocks);
+      void compress_n(const byte[], size_t blocks);
       void copy_out(byte[]);
 
       SecureVector<u64bit> W, digest;
diff --git a/src/hash/skein/skein_512.cpp b/src/hash/skein/skein_512.cpp
index a3aff52ab..665dd7248 100644
--- a/src/hash/skein/skein_512.cpp
+++ b/src/hash/skein/skein_512.cpp
@@ -29,11 +29,11 @@ enum type_code {
 
 void ubi_512(MemoryRegion<u64bit>& H,
              MemoryRegion<u64bit>& T,
-             const byte msg[], u32bit msg_len)
+             const byte msg[], size_t msg_len)
    {
    do
       {
-      const u32bit to_proc = std::min<u32bit>(msg_len, 64);
+      const size_t to_proc = std::min<size_t>(msg_len, 64);
       T[0] += to_proc;
 
       u64bit M[8] = { 0 };
@@ -42,7 +42,7 @@ void ubi_512(MemoryRegion<u64bit>& H,
 
       if(to_proc % 8)
          {
-         for(u32bit j = 0; j != to_proc % 8; ++j)
+         for(size_t j = 0; j != to_proc % 8; ++j)
             M[to_proc/8] |= ((u64bit)msg[8*(to_proc/8)+j] << (8*j));
          }
 
@@ -197,7 +197,7 @@ void Skein_512::clear()
    buf_pos = 0;
    }
 
-void Skein_512::add_data(const byte input[], u32bit length)
+void Skein_512::add_data(const byte input[], size_t length)
    {
    if(length == 0)
       return;
@@ -215,7 +215,7 @@ void Skein_512::add_data(const byte input[], u32bit length)
          }
       }
 
-   const u32bit full_blocks = (length - 1) / 64;
+   const size_t full_blocks = (length - 1) / 64;
 
    if(full_blocks)
       ubi_512(H, T, input, 64*full_blocks);
@@ -230,33 +230,33 @@ void Skein_512::final_result(byte out[])
    {
    T[1] |= ((u64bit)1 << 63); // final block flag
 
-   for(u32bit i = buf_pos; i != buffer.size(); ++i)
+   for(size_t i = buf_pos; i != buffer.size(); ++i)
       buffer[i] = 0;
 
    ubi_512(H, T, &buffer[0], buf_pos);
 
    byte counter[8] = { 0 };
 
-   u32bit out_bytes = output_bits / 8;
+   size_t out_bytes = output_bits / 8;
 
    SecureVector<u64bit> H_out(9);
 
    while(out_bytes)
       {
-      const u32bit to_proc = std::min<u32bit>(out_bytes, 64);
+      const size_t to_proc = std::min<size_t>(out_bytes, 64);
 
       H_out.copy(&H[0], 8);
 
       reset_tweak(T, SKEIN_OUTPUT, true);
       ubi_512(H_out, T, counter, sizeof(counter));
 
-      for(u32bit i = 0; i != to_proc; ++i)
+      for(size_t i = 0; i != to_proc; ++i)
          out[i] = get_byte(7-i%8, H_out[i/8]);
 
       out_bytes -= to_proc;
       out += to_proc;
 
-      for(u32bit i = 0; i != sizeof(counter); ++i)
+      for(size_t i = 0; i != sizeof(counter); ++i)
          if(++counter[i])
             break;
       }
diff --git a/src/hash/skein/skein_512.h b/src/hash/skein/skein_512.h
index 811b633eb..803f1c916 100644
--- a/src/hash/skein/skein_512.h
+++ b/src/hash/skein/skein_512.h
@@ -32,16 +32,16 @@ class BOTAN_DLL Skein_512 : public HashFunction
       std::string name() const;
       void clear();
    private:
-      void add_data(const byte input[], u32bit length);
+      void add_data(const byte input[], size_t length);
       void final_result(byte out[]);
 
       std::string personalization;
-      u32bit output_bits;
+      size_t output_bits;
 
       SecureVector<u64bit> H;
       SecureVector<u64bit> T;
       SecureVector<byte> buffer;
-      u32bit buf_pos;
+      size_t buf_pos;
    };
 
 }
diff --git a/src/hash/tiger/tiger.cpp b/src/hash/tiger/tiger.cpp
index 9d3e2cbe4..fa5effd80 100644
--- a/src/hash/tiger/tiger.cpp
+++ b/src/hash/tiger/tiger.cpp
@@ -43,11 +43,11 @@ inline void mix(MemoryRegion<u64bit>& X)
 /*
 * Tiger Compression Function
 */
-void Tiger::compress_n(const byte input[], u32bit blocks)
+void Tiger::compress_n(const byte input[], size_t blocks)
    {
    u64bit A = digest[0], B = digest[1], C = digest[2];
 
-   for(u32bit i = 0; i != blocks; ++i)
+   for(size_t i = 0; i != blocks; ++i)
       {
       load_le(&X[0], input, X.size());
 
@@ -55,7 +55,7 @@ void Tiger::compress_n(const byte input[], u32bit blocks)
       pass(C, A, B, X, 7); mix(X);
       pass(B, C, A, X, 9);
 
-      for(u32bit j = 3; j != PASS; ++j)
+      for(size_t j = 3; j != PASS; ++j)
          {
          mix(X);
          pass(A, B, C, X, 9);
@@ -75,8 +75,8 @@ void Tiger::compress_n(const byte input[], u32bit blocks)
 */
 void Tiger::copy_out(byte output[])
    {
-   for(u32bit j = 0; j != OUTPUT_LENGTH; ++j)
-      output[j] = get_byte(7 - (j % 8), digest[j/8]);
+   for(size_t i = 0; i != OUTPUT_LENGTH; ++i)
+      output[i] = get_byte(7 - (i % 8), digest[i/8]);
    }
 
 /*
@@ -166,7 +166,7 @@ std::string Tiger::name() const
 /*
 * Tiger Constructor
 */
-Tiger::Tiger(u32bit hashlen, u32bit pass) :
+Tiger::Tiger(size_t hashlen, size_t pass) :
    MDx_HashFunction(hashlen, 64, false, false),
    X(8),
    digest(3),
diff --git a/src/hash/tiger/tiger.h b/src/hash/tiger/tiger.h
index 4b8a99344..7305ddb46 100644
--- a/src/hash/tiger/tiger.h
+++ b/src/hash/tiger/tiger.h
@@ -30,9 +30,9 @@ class BOTAN_DLL Tiger : public MDx_HashFunction
       * @param out_size specifies the output length; can be 16, 20, or 24
       * @param passes to make in the algorithm
       */
-      Tiger(u32bit out_size = 24, u32bit passes = 3);
+      Tiger(size_t out_size = 24, size_t passes = 3);
    private:
-      void compress_n(const byte[], u32bit block);
+      void compress_n(const byte[], size_t block);
       void copy_out(byte[]);
 
       static void pass(u64bit& A, u64bit& B, u64bit& C,
@@ -45,7 +45,7 @@ class BOTAN_DLL Tiger : public MDx_HashFunction
       static const u64bit SBOX4[256];
 
       SecureVector<u64bit> X, digest;
-      const u32bit PASS;
+      const size_t PASS;
    };
 
 }
diff --git a/src/hash/whirlpool/whrlpool.cpp b/src/hash/whirlpool/whrlpool.cpp
index fcd244ce2..fdbdf5d0f 100644
--- a/src/hash/whirlpool/whrlpool.cpp
+++ b/src/hash/whirlpool/whrlpool.cpp
@@ -13,7 +13,7 @@ namespace Botan {
 /*
 * Whirlpool Compression Function
 */
-void Whirlpool::compress_n(const byte in[], u32bit blocks)
+void Whirlpool::compress_n(const byte in[], size_t blocks)
    {
    static const u64bit RC[10] = {
       0x1823C6E887B8014F, 0x36A6D2F5796F9152,
@@ -23,7 +23,7 @@ void Whirlpool::compress_n(const byte in[], u32bit blocks)
       0xFBEE7C66DD17479E, 0xCA2DBF07AD5A8333
    };
 
-   for(u32bit i = 0; i != blocks; ++i)
+   for(size_t i = 0; i != blocks; ++i)
       {
       load_be(&M[0], in, M.size());
 
@@ -35,7 +35,7 @@ void Whirlpool::compress_n(const byte in[], u32bit blocks)
       B0 = K0 ^ M[0]; B1 = K1 ^ M[1]; B2 = K2 ^ M[2]; B3 = K3 ^ M[3];
       B4 = K4 ^ M[4]; B5 = K5 ^ M[5]; B6 = K6 ^ M[6]; B7 = K7 ^ M[7];
 
-      for(u32bit j = 0; j != 10; ++j)
+      for(size_t j = 0; j != 10; ++j)
          {
          u64bit T0, T1, T2, T3, T4, T5, T6, T7;
          T0 = C0[get_byte(0, K0)] ^ C1[get_byte(1, K7)] ^
@@ -129,8 +129,8 @@ void Whirlpool::compress_n(const byte in[], u32bit blocks)
 */
 void Whirlpool::copy_out(byte output[])
    {
-   for(u32bit j = 0; j != OUTPUT_LENGTH; j += 8)
-      store_be(digest[j/8], output + j);
+   for(size_t i = 0; i != OUTPUT_LENGTH; i += 8)
+      store_be(digest[i/8], output + i);
    }
 
 /*
diff --git a/src/hash/whirlpool/whrlpool.h b/src/hash/whirlpool/whrlpool.h
index 98be0b480..30bf91a34 100644
--- a/src/hash/whirlpool/whrlpool.h
+++ b/src/hash/whirlpool/whrlpool.h
@@ -25,7 +25,7 @@ class BOTAN_DLL Whirlpool : public MDx_HashFunction
       Whirlpool() : MDx_HashFunction(64, 64, true, true, 32), M(8), digest(8)
          { clear(); }
    private:
-      void compress_n(const byte[], u32bit blocks);
+      void compress_n(const byte[], size_t blocks);
       void copy_out(byte[]);
 
       static const u64bit C0[256];
diff --git a/src/mac/cbc_mac/cbc_mac.cpp b/src/mac/cbc_mac/cbc_mac.cpp
index 5b9708d41..1b03f0ab9 100644
--- a/src/mac/cbc_mac/cbc_mac.cpp
+++ b/src/mac/cbc_mac/cbc_mac.cpp
@@ -14,9 +14,9 @@ namespace Botan {
 /*
 * Update an CBC-MAC Calculation
 */
-void CBC_MAC::add_data(const byte input[], u32bit length)
+void CBC_MAC::add_data(const byte input[], size_t length)
    {
-   u32bit xored = std::min(OUTPUT_LENGTH - position, length);
+   size_t xored = std::min(OUTPUT_LENGTH - position, length);
    xor_buf(&state[position], input, xored);
    position += xored;
 
diff --git a/src/mac/cbc_mac/cbc_mac.h b/src/mac/cbc_mac/cbc_mac.h
index 772abd38f..69fef9c57 100644
--- a/src/mac/cbc_mac/cbc_mac.h
+++ b/src/mac/cbc_mac/cbc_mac.h
@@ -29,13 +29,13 @@ class BOTAN_DLL CBC_MAC : public MessageAuthenticationCode
       CBC_MAC(BlockCipher* cipher);
       ~CBC_MAC();
    private:
-      void add_data(const byte[], u32bit);
+      void add_data(const byte[], size_t);
       void final_result(byte[]);
       void key_schedule(const byte[], u32bit);
 
       BlockCipher* e;
       SecureVector<byte> state;
-      u32bit position;
+      size_t position;
    };
 
 }
diff --git a/src/mac/cmac/cmac.cpp b/src/mac/cmac/cmac.cpp
index 38b62c6cb..05fa7d037 100644
--- a/src/mac/cmac/cmac.cpp
+++ b/src/mac/cmac/cmac.cpp
@@ -21,10 +21,10 @@ SecureVector<byte> CMAC::poly_double(const MemoryRegion<byte>& in,
    SecureVector<byte> out = in;
 
    byte carry = 0;
-   for(u32bit j = out.size(); j != 0; --j)
+   for(size_t i = out.size(); i != 0; --i)
       {
-      byte temp = out[j-1];
-      out[j-1] = (temp << 1) | carry;
+      byte temp = out[i-1];
+      out[i-1] = (temp << 1) | carry;
       carry = (temp >> 7);
       }
 
@@ -37,7 +37,7 @@ SecureVector<byte> CMAC::poly_double(const MemoryRegion<byte>& in,
 /*
 * Update an CMAC Calculation
 */
-void CMAC::add_data(const byte input[], u32bit length)
+void CMAC::add_data(const byte input[], size_t length)
    {
    buffer.copy(position, input, length);
    if(position + length > OUTPUT_LENGTH)
@@ -78,8 +78,8 @@ void CMAC::final_result(byte mac[])
 
    e->encrypt(state);
 
-   for(u32bit j = 0; j != OUTPUT_LENGTH; ++j)
-      mac[j] = state[j];
+   for(size_t i = 0; i != OUTPUT_LENGTH; ++i)
+      mac[i] = state[i];
 
    zeroise(state);
    zeroise(buffer);
diff --git a/src/mac/cmac/cmac.h b/src/mac/cmac/cmac.h
index b5f3eec1a..5655e1eea 100644
--- a/src/mac/cmac/cmac.h
+++ b/src/mac/cmac/cmac.h
@@ -37,13 +37,13 @@ class BOTAN_DLL CMAC : public MessageAuthenticationCode
       CMAC(BlockCipher* cipher);
       ~CMAC();
    private:
-      void add_data(const byte[], u32bit);
+      void add_data(const byte[], size_t);
       void final_result(byte[]);
       void key_schedule(const byte[], u32bit);
 
       BlockCipher* e;
       SecureVector<byte> buffer, state, B, P;
-      u32bit position;
+      size_t position;
       byte polynomial;
    };
 
diff --git a/src/mac/hmac/hmac.cpp b/src/mac/hmac/hmac.cpp
index 1ad9487b4..c842a944d 100644
--- a/src/mac/hmac/hmac.cpp
+++ b/src/mac/hmac/hmac.cpp
@@ -14,7 +14,7 @@ namespace Botan {
 /*
 * Update a HMAC Calculation
 */
-void HMAC::add_data(const byte input[], u32bit length)
+void HMAC::add_data(const byte input[], size_t length)
    {
    hash->update(input, length);
    }
diff --git a/src/mac/hmac/hmac.h b/src/mac/hmac/hmac.h
index 43a5d22a4..3941baef9 100644
--- a/src/mac/hmac/hmac.h
+++ b/src/mac/hmac/hmac.h
@@ -29,7 +29,7 @@ class BOTAN_DLL HMAC : public MessageAuthenticationCode
       HMAC(HashFunction* hash);
       ~HMAC() { delete hash; }
    private:
-      void add_data(const byte[], u32bit);
+      void add_data(const byte[], size_t);
       void final_result(byte[]);
       void key_schedule(const byte[], u32bit);
       HashFunction* hash;
diff --git a/src/mac/ssl3mac/ssl3_mac.cpp b/src/mac/ssl3mac/ssl3_mac.cpp
index 781cb7f27..fc8d652c6 100644
--- a/src/mac/ssl3mac/ssl3_mac.cpp
+++ b/src/mac/ssl3mac/ssl3_mac.cpp
@@ -12,7 +12,7 @@ namespace Botan {
 /*
 * Update a SSL3-MAC Calculation
 */
-void SSL3_MAC::add_data(const byte input[], u32bit length)
+void SSL3_MAC::add_data(const byte input[], size_t length)
    {
    hash->update(input, length);
    }
@@ -80,7 +80,7 @@ SSL3_MAC::SSL3_MAC(HashFunction* hash_in) :
    if(hash->HASH_BLOCK_SIZE == 0)
       throw Invalid_Argument("SSL3-MAC cannot be used with " + hash->name());
 
-   u32bit INNER_HASH_LENGTH =
+   size_t INNER_HASH_LENGTH =
       (hash->name() == "SHA-160") ? 60 : hash->HASH_BLOCK_SIZE;
 
    i_key.resize(INNER_HASH_LENGTH);
diff --git a/src/mac/ssl3mac/ssl3_mac.h b/src/mac/ssl3mac/ssl3_mac.h
index 019163ec8..4d7b07dcc 100644
--- a/src/mac/ssl3mac/ssl3_mac.h
+++ b/src/mac/ssl3mac/ssl3_mac.h
@@ -29,7 +29,7 @@ class BOTAN_DLL SSL3_MAC : public MessageAuthenticationCode
       SSL3_MAC(HashFunction* hash);
       ~SSL3_MAC() { delete hash; }
    private:
-      void add_data(const byte[], u32bit);
+      void add_data(const byte[], size_t);
       void final_result(byte[]);
       void key_schedule(const byte[], u32bit);
 
diff --git a/src/mac/x919_mac/x919_mac.cpp b/src/mac/x919_mac/x919_mac.cpp
index 0515dbee9..ef812ff81 100644
--- a/src/mac/x919_mac/x919_mac.cpp
+++ b/src/mac/x919_mac/x919_mac.cpp
@@ -14,9 +14,9 @@ namespace Botan {
 /*
 * Update an ANSI X9.19 MAC Calculation
 */
-void ANSI_X919_MAC::add_data(const byte input[], u32bit length)
+void ANSI_X919_MAC::add_data(const byte input[], size_t length)
    {
-   u32bit xored = std::min(8 - position, length);
+   size_t xored = std::min(8 - position, length);
    xor_buf(&state[position], input, xored);
    position += xored;
 
diff --git a/src/mac/x919_mac/x919_mac.h b/src/mac/x919_mac/x919_mac.h
index 275d39367..a1710b654 100644
--- a/src/mac/x919_mac/x919_mac.h
+++ b/src/mac/x919_mac/x919_mac.h
@@ -29,14 +29,14 @@ class BOTAN_DLL ANSI_X919_MAC : public MessageAuthenticationCode
       ANSI_X919_MAC(BlockCipher* cipher);
       ~ANSI_X919_MAC();
    private:
-      void add_data(const byte[], u32bit);
+      void add_data(const byte[], size_t);
       void final_result(byte[]);
       void key_schedule(const byte[], u32bit);
 
       BlockCipher* e;
       BlockCipher* d;
       SecureVector<byte> state;
-      u32bit position;
+      size_t position;
    };
 
 }
diff --git a/src/pbkdf/pbkdf2/pbkdf2.cpp b/src/pbkdf/pbkdf2/pbkdf2.cpp
index b1c7b2e07..88131da01 100644
--- a/src/pbkdf/pbkdf2/pbkdf2.cpp
+++ b/src/pbkdf/pbkdf2/pbkdf2.cpp
@@ -42,7 +42,7 @@ OctetString PKCS5_PBKDF2::derive_key(u32bit key_len,
    u32bit counter = 1;
    while(key_len)
       {
-      u32bit T_size = std::min(mac->OUTPUT_LENGTH, key_len);
+      u32bit T_size = std::min<u32bit>(mac->OUTPUT_LENGTH, key_len);
 
       mac->update(salt, salt_size);
       for(u32bit j = 0; j != 4; ++j)
diff --git a/src/utils/buf_comp/buf_comp.h b/src/utils/buf_comp/buf_comp.h
index 784a3285d..0904941d6 100644
--- a/src/utils/buf_comp/buf_comp.h
+++ b/src/utils/buf_comp/buf_comp.h
@@ -25,14 +25,14 @@ class BOTAN_DLL BufferedComputation
       /**
       * The length of the output of this function in bytes.
       */
-      const u32bit OUTPUT_LENGTH;
+      const size_t OUTPUT_LENGTH;
 
       /**
       * Add new input to process.
       * @param in the input to process as a byte array
       * @param length of param in in bytes
       */
-      void update(const byte in[], u32bit length) { add_data(in, length); }
+      void update(const byte in[], size_t length) { add_data(in, length); }
 
       /**
       * Add new input to process.
@@ -96,7 +96,7 @@ class BOTAN_DLL BufferedComputation
       * @param length the length of the byte array
       * @result the result of the call to final()
       */
-      SecureVector<byte> process(const byte in[], u32bit length)
+      SecureVector<byte> process(const byte in[], size_t length)
          {
          add_data(in, length);
          return final();
@@ -129,7 +129,7 @@ class BOTAN_DLL BufferedComputation
       /**
       * @param out_len the output length of this computation
       */
-      BufferedComputation(u32bit out_len) : OUTPUT_LENGTH(out_len) {}
+      BufferedComputation(size_t out_len) : OUTPUT_LENGTH(out_len) {}
 
       virtual ~BufferedComputation() {}
    private:
@@ -140,7 +140,7 @@ class BOTAN_DLL BufferedComputation
       * @param input is an input buffer
       * @param length is the length of input in bytes
       */
-      virtual void add_data(const byte input[], u32bit length) = 0;
+      virtual void add_data(const byte input[], size_t length) = 0;
 
       /**
       * Write the final output to out
diff --git a/src/utils/xor_buf.h b/src/utils/xor_buf.h
index 34abb48d3..3c96dea70 100644
--- a/src/utils/xor_buf.h
+++ b/src/utils/xor_buf.h
@@ -18,7 +18,7 @@ namespace Botan {
 * @param in the read-only input buffer
 * @param length the length of the buffers
 */
-inline void xor_buf(byte out[], const byte in[], u32bit length)
+inline void xor_buf(byte out[], const byte in[], size_t length)
    {
    while(length >= 8)
       {
@@ -33,8 +33,9 @@ inline void xor_buf(byte out[], const byte in[], u32bit length)
 
       out += 8; in += 8; length -= 8;
       }
-   for(u32bit j = 0; j != length; ++j)
-      out[j] ^= in[j];
+
+   for(size_t i = 0; i != length; ++i)
+      out[i] ^= in[i];
    }
 
 /**
@@ -47,7 +48,7 @@ inline void xor_buf(byte out[], const byte in[], u32bit length)
 inline void xor_buf(byte out[],
                     const byte in[],
                     const byte in2[],
-                    u32bit length)
+                    size_t length)
    {
    while(length >= 8)
       {
@@ -65,8 +66,8 @@ inline void xor_buf(byte out[],
       in += 8; in2 += 8; out += 8; length -= 8;
       }
 
-   for(u32bit j = 0; j != length; ++j)
-      out[j] = in[j] ^ in2[j];
+   for(size_t i = 0; i != length; ++i)
+      out[i] = in[i] ^ in2[i];
    }
 
 }