Anywhere where we use MemoryRegion::begin to get access to the raw pointer

representation (rather than in an interator context), instead use &buf[0],
which works for both MemoryRegion and std::vector

60 files changed, 160 insertions, 151 deletions

diff --git a/src/alloc/secmem.h b/src/alloc/secmem.h
index f7aa6f3d1..dc5e90b79 100644
--- a/src/alloc/secmem.h
+++ b/src/alloc/secmem.h
@@ -101,7 +101,11 @@ class MemoryRegion
       * @return reference to *this
       */
       MemoryRegion<T>& operator=(const MemoryRegion<T>& other)
-         { if(this != &other) set(other); return (*this); }
+         {
+         if(this != &other)
+            set(&other[0], other.size());
+         return (*this);
+         }
 
       /**
       * Copy the contents of an array of objects of type T into this buffer.
@@ -126,6 +130,14 @@ class MemoryRegion
          { copy_mem(buf + off, in, (n > size() - off) ? (size() - off) : n); }
 
       /**
+      * Set the contents of this according to the argument. The size of
+      * this is increased if necessary.
+      * @param in the array of objects of type T to copy the contents from
+      * @param n the size of array in
+      */
+      void set(const T in[], u32bit n)    { resize(n); copy(in, n); }
+
+      /**
       * Append data to the end of this buffer.
       * @param data the array containing the data to append
       * @param n the size of the array data
@@ -144,7 +156,7 @@ class MemoryRegion
       * @param other the buffer containing the data to append
       */
       void append(const MemoryRegion<T>& other)
-         { append(other.begin(), other.size()); }
+         { append(&other[0], other.size()); }
 
       /**
       * Reset this buffer to an empty buffer with size zero.
@@ -187,21 +199,6 @@ class MemoryRegion
       void init(bool locking, u32bit length = 0)
          { alloc = Allocator::get(locking); resize(length); }
 
-      /**
-      * Set the contents of this according to the argument. The size of
-      * *this is increased if necessary.
-      * @param in the array of objects of type T to copy the contents from
-      * @param n the size of array in
-      */
-      void set(const T in[], u32bit n)    { resize(n); copy(in, n); }
-
-      /**
-      * Set the contents of this according to the argument. The size of
-      * *this is increased if necessary.
-      * @param in the buffer to copy the contents from
-      */
-      void set(const MemoryRegion<T>& in) { set(in.begin(), in.size()); }
-
    private:
       T* allocate(u32bit n)
          {
@@ -290,7 +287,11 @@ class MemoryVector : public MemoryRegion<T>
       * @return reference to *this
       */
       MemoryVector<T>& operator=(const MemoryRegion<T>& in)
-         { if(this != &in) set(in); return (*this); }
+         {
+         if(this != &in)
+            set(&in[0], in.size());
+         return (*this);
+         }
 
       /**
       * Create a buffer of the specified length.
@@ -311,7 +312,7 @@ class MemoryVector : public MemoryRegion<T>
       * Copy constructor.
       */
       MemoryVector(const MemoryRegion<T>& in)
-         { init(false); set(in); }
+         { init(false); set(&in[0], in.size()); }
 
       /**
       * Create a buffer whose content is the concatenation of two other
@@ -320,7 +321,7 @@ class MemoryVector : public MemoryRegion<T>
       * @param in2 the contents to be appended to in1
       */
       MemoryVector(const MemoryRegion<T>& in1, const MemoryRegion<T>& in2)
-         { init(false); set(in1); append(in2); }
+         { init(false); set(&in1[0], in1.size()); append(in2); }
    };
 
 /**
@@ -344,7 +345,7 @@ class SecureVector : public MemoryRegion<T>
       * @return reference to *this
       */
       SecureVector<T>& operator=(const MemoryRegion<T>& in)
-         { if(this != &in) set(in); return (*this); }
+         { if(this != &in) set(&in[0], in.size()); return (*this); }
 
       /**
       * Create a buffer of the specified length.
@@ -363,9 +364,9 @@ class SecureVector : public MemoryRegion<T>
          {
          init(true, INITIAL_LEN);
          if(INITIAL_LEN)
-            copy(in, n);
+            copy(&in[0], n);
          else
-            set(in, n);
+            set(&in[0], n);
          }
 
       /**
@@ -377,9 +378,9 @@ class SecureVector : public MemoryRegion<T>
          {
          init(true, INITIAL_LEN);
          if(INITIAL_LEN)
-            copy(in, in.size());
+            copy(&in[0], in.size());
          else
-            set(in);
+            set(&in[0], in.size());
          }
 
       /**
@@ -389,7 +390,7 @@ class SecureVector : public MemoryRegion<T>
       * @param in2 the contents to be appended to in1
       */
       SecureVector(const MemoryRegion<T>& in1, const MemoryRegion<T>& in2)
-         { init(true); set(in1); append(in2); }
+         { init(true); set(&in1[0], in1.size()); append(in2); }
    };
 
 /**
diff --git a/src/asn1/asn1_alt.cpp b/src/asn1/asn1_alt.cpp
index 9fe159356..1fccf6ac0 100644
--- a/src/asn1/asn1_alt.cpp
+++ b/src/asn1/asn1_alt.cpp
@@ -217,7 +217,7 @@ void AlternativeName::decode_from(BER_Decoder& source)
          {
          if(obj.value.size() == 4)
             {
-            u32bit ip = load_be<u32bit>(obj.value.begin(), 0);
+            u32bit ip = load_be<u32bit>(&obj.value[0], 0);
             add_attribute("IP", ipv4_to_string(ip));
             }
          }
diff --git a/src/asn1/asn1_int.cpp b/src/asn1/asn1_int.cpp
index 5e18f3961..75cb1f90c 100644
--- a/src/asn1/asn1_int.cpp
+++ b/src/asn1/asn1_int.cpp
@@ -45,7 +45,7 @@ SecureVector<byte> put_in_sequence(const MemoryRegion<byte>& contents)
 */
 std::string to_string(const BER_Object& obj)
    {
-   return std::string(reinterpret_cast<const char*>(obj.value.begin()),
+   return std::string(reinterpret_cast<const char*>(&obj.value[0]),
                       obj.value.size());
    }
 
diff --git a/src/asn1/der_enc.cpp b/src/asn1/der_enc.cpp
index dd173590f..0ce633c7a 100644
--- a/src/asn1/der_enc.cpp
+++ b/src/asn1/der_enc.cpp
@@ -180,7 +180,7 @@ DER_Encoder& DER_Encoder::end_explicit()
 */
 DER_Encoder& DER_Encoder::raw_bytes(const MemoryRegion<byte>& val)
    {
-   return raw_bytes(val.begin(), val.size());
+   return raw_bytes(&val[0], val.size());
    }
 
 /*
@@ -234,7 +234,7 @@ DER_Encoder& DER_Encoder::encode(const BigInt& n)
 DER_Encoder& DER_Encoder::encode(const MemoryRegion<byte>& bytes,
                                  ASN1_Tag real_type)
    {
-   return encode(bytes.begin(), bytes.size(),
+   return encode(&bytes[0], bytes.size(),
                  real_type, real_type, UNIVERSAL);
    }
 
@@ -277,7 +277,7 @@ DER_Encoder& DER_Encoder::encode(const BigInt& n,
 
    bool extra_zero = (n.bits() % 8 == 0);
    SecureVector<byte> contents(extra_zero + n.bytes());
-   BigInt::encode(contents.begin() + extra_zero, n);
+   BigInt::encode(&contents[extra_zero], n);
    if(n < 0)
       {
       for(u32bit j = 0; j != contents.size(); ++j)
@@ -297,7 +297,7 @@ DER_Encoder& DER_Encoder::encode(const MemoryRegion<byte>& bytes,
                                  ASN1_Tag real_type,
                                  ASN1_Tag type_tag, ASN1_Tag class_tag)
    {
-   return encode(bytes.begin(), bytes.size(),
+   return encode(&bytes[0], bytes.size(),
                  real_type, type_tag, class_tag);
    }
 
@@ -364,7 +364,7 @@ DER_Encoder& DER_Encoder::add_object(ASN1_Tag type_tag, ASN1_Tag class_tag,
 DER_Encoder& DER_Encoder::add_object(ASN1_Tag type_tag, ASN1_Tag class_tag,
                                      const MemoryRegion<byte>& rep_buf)
    {
-   const byte* rep = rep_buf.begin();
+   const byte* rep = &rep_buf[0];
    const u32bit rep_len = rep_buf.size();
    return add_object(type_tag, class_tag, rep, rep_len);
    }
diff --git a/src/block/des/des.cpp b/src/block/des/des.cpp
index bbe564827..a24a1d445 100644
--- a/src/block/des/des.cpp
+++ b/src/block/des/des.cpp
@@ -203,7 +203,7 @@ void DES::decrypt_n(const byte in[], byte out[], u32bit blocks) const
 */
 void DES::key_schedule(const byte key[], u32bit)
    {
-   des_key_schedule(round_key.begin(), key);
+   des_key_schedule(&round_key[0], key);
    }
 
 /*
@@ -283,7 +283,7 @@ void TripleDES::key_schedule(const byte key[], u32bit length)
    if(length == 24)
       des_key_schedule(&round_key[64], key + 16);
    else
-      copy_mem(&round_key[64], round_key.begin(), 32);
+      copy_mem(&round_key[64], &round_key[0], 32);
    }
 
 }
diff --git a/src/block/des/desx.cpp b/src/block/des/desx.cpp
index d19d7da8a..cc97c4e7b 100644
--- a/src/block/des/desx.cpp
+++ b/src/block/des/desx.cpp
@@ -17,9 +17,9 @@ void DESX::encrypt_n(const byte in[], byte out[], u32bit blocks) const
    {
    for(u32bit i = 0; i != blocks; ++i)
       {
-      xor_buf(out, in, K1.begin(), BLOCK_SIZE);
+      xor_buf(out, in, &K1[0], BLOCK_SIZE);
       des.encrypt(out);
-      xor_buf(out, K2.begin(), BLOCK_SIZE);
+      xor_buf(out, &K2[0], BLOCK_SIZE);
 
       in += BLOCK_SIZE;
       out += BLOCK_SIZE;
@@ -33,9 +33,9 @@ void DESX::decrypt_n(const byte in[], byte out[], u32bit blocks) const
    {
    for(u32bit i = 0; i != blocks; ++i)
       {
-      xor_buf(out, in, K2.begin(), BLOCK_SIZE);
+      xor_buf(out, in, &K2[0], BLOCK_SIZE);
       des.decrypt(out);
-      xor_buf(out, K1.begin(), BLOCK_SIZE);
+      xor_buf(out, &K1[0], BLOCK_SIZE);
 
       in += BLOCK_SIZE;
       out += BLOCK_SIZE;
diff --git a/src/cert/cvc/ecdsa_sig.cpp b/src/cert/cvc/ecdsa_sig.cpp
index e003bb369..6a44f6803 100644
--- a/src/cert/cvc/ecdsa_sig.cpp
+++ b/src/cert/cvc/ecdsa_sig.cpp
@@ -47,13 +47,11 @@ ECDSA_Signature decode_concatenation(const MemoryRegion<byte>& concat)
    if(concat.size() % 2 != 0)
       throw Invalid_Argument("Erroneous length of signature");
 
-   u32bit rs_len = concat.size()/2;
-   SecureVector<byte> sv_r;
-   SecureVector<byte> sv_s;
-   sv_r.set(concat.begin(), rs_len);
-   sv_s.set(&concat[rs_len], rs_len);
-   BigInt r = BigInt::decode(sv_r, sv_r.size());
-   BigInt s = BigInt::decode(sv_s, sv_s.size());
+   const u32bit rs_len = concat.size() / 2;
+
+   BigInt r = BigInt::decode(&concat[0], rs_len);
+   BigInt s = BigInt::decode(&concat[rs_len], rs_len);
+
    return ECDSA_Signature(r, s);
    }
 
diff --git a/src/cms/cms_dec.cpp b/src/cms/cms_dec.cpp
index fdb9a4a54..c86e1d0ae 100644
--- a/src/cms/cms_dec.cpp
+++ b/src/cms/cms_dec.cpp
@@ -86,7 +86,7 @@ std::string CMS_Decoder::get_data() const
    {
    if(layer_type() != DATA)
       throw Invalid_State("CMS: Cannot retrieve data from non-DATA layer");
-   return std::string((const char*)data.begin(), data.size());
+   return std::string((const char*)&data[0], data.size());
    }
 
 /*
diff --git a/src/constructs/cryptobox/cryptobox.cpp b/src/constructs/cryptobox/cryptobox.cpp
index 61fe51a88..0c37949bc 100644
--- a/src/constructs/cryptobox/cryptobox.cpp
+++ b/src/constructs/cryptobox/cryptobox.cpp
@@ -45,18 +45,22 @@ std::string encrypt(const byte input[], u32bit input_len,
                     RandomNumberGenerator& rng)
    {
    SecureVector<byte> pbkdf_salt(PBKDF_SALT_LEN);
-   rng.randomize(pbkdf_salt.begin(), pbkdf_salt.size());
+   rng.randomize(&pbkdf_salt[0], pbkdf_salt.size());
 
    PKCS5_PBKDF2 pbkdf(new HMAC(new SHA_512));
 
-   OctetString mk = pbkdf.derive_key(PBKDF_OUTPUT_LEN, passphrase,
-                                     &pbkdf_salt[0], pbkdf_salt.size(),
-                                     PBKDF_ITERATIONS);
+   OctetString master_key = pbkdf.derive_key(
+      PBKDF_OUTPUT_LEN,
+      passphrase,
+      &pbkdf_salt[0],
+      pbkdf_salt.size(),
+      PBKDF_ITERATIONS);
 
-   SymmetricKey cipher_key(mk.begin(), CIPHER_KEY_LEN);
-   SymmetricKey mac_key(mk.begin() + CIPHER_KEY_LEN, MAC_KEY_LEN);
-   InitializationVector iv(mk.begin() + CIPHER_KEY_LEN + MAC_KEY_LEN,
-                           CIPHER_IV_LEN);
+   const byte* mk = master_key.begin();
+
+   SymmetricKey cipher_key(&mk[0], CIPHER_KEY_LEN);
+   SymmetricKey mac_key(&mk[CIPHER_KEY_LEN], MAC_KEY_LEN);
+   InitializationVector iv(&mk[CIPHER_KEY_LEN + MAC_KEY_LEN], CIPHER_IV_LEN);
 
    Pipe pipe(get_cipher("Serpent/CTR-BE", cipher_key, iv, ENCRYPTION),
              new Fork(
@@ -89,8 +93,7 @@ std::string encrypt(const byte input[], u32bit input_len,
    pipe.read(out_buf + VERSION_CODE_LEN + PBKDF_SALT_LEN + MAC_OUTPUT_LEN,
              ciphertext_len, 0);
 
-   return PEM_Code::encode(out_buf.begin(), out_buf.size(),
-                           "BOTAN CRYPTOBOX MESSAGE");
+   return PEM_Code::encode(out_buf, "BOTAN CRYPTOBOX MESSAGE");
    }
 
 std::string decrypt(const byte input[], u32bit input_len,
@@ -112,14 +115,18 @@ std::string decrypt(const byte input[], u32bit input_len,
 
    PKCS5_PBKDF2 pbkdf(new HMAC(new SHA_512));
 
-   OctetString mk = pbkdf.derive_key(PBKDF_OUTPUT_LEN, passphrase,
-                                     &pbkdf_salt[0], pbkdf_salt.size(),
-                                     PBKDF_ITERATIONS);
+   OctetString master_key = pbkdf.derive_key(
+      PBKDF_OUTPUT_LEN,
+      passphrase,
+      &pbkdf_salt[0],
+      pbkdf_salt.size(),
+      PBKDF_ITERATIONS);
+
+   const byte* mk = master_key.begin();
 
-   SymmetricKey cipher_key(mk.begin(), CIPHER_KEY_LEN);
-   SymmetricKey mac_key(mk.begin() + CIPHER_KEY_LEN, MAC_KEY_LEN);
-   InitializationVector iv(mk.begin() + CIPHER_KEY_LEN + MAC_KEY_LEN,
-                           CIPHER_IV_LEN);
+   SymmetricKey cipher_key(&mk[0], CIPHER_KEY_LEN);
+   SymmetricKey mac_key(&mk[CIPHER_KEY_LEN], MAC_KEY_LEN);
+   InitializationVector iv(&mk[CIPHER_KEY_LEN + MAC_KEY_LEN], CIPHER_IV_LEN);
 
    Pipe pipe(new Fork(
                 get_cipher("Serpent/CTR-BE", cipher_key, iv, DECRYPTION),
diff --git a/src/constructs/passhash/passhash9.cpp b/src/constructs/passhash/passhash9.cpp
index 6618f36fa..c120b39c5 100644
--- a/src/constructs/passhash/passhash9.cpp
+++ b/src/constructs/passhash/passhash9.cpp
@@ -139,8 +139,8 @@ bool check_passhash9(const std::string& pass, const std::string& hash)
       &bin[ALGID_BYTES + WORKFACTOR_BYTES], SALT_BYTES,
       kdf_iterations).bits_of();
 
-   return same_mem(cmp.begin(),
-                   bin.begin() + ALGID_BYTES + WORKFACTOR_BYTES + SALT_BYTES,
+   return same_mem(&cmp[0],
+                   &bin[ALGID_BYTES + WORKFACTOR_BYTES + SALT_BYTES],
                    PASSHASH9_PBKDF_OUTPUT_LEN);
    }
 
diff --git a/src/constructs/tss/tss.cpp b/src/constructs/tss/tss.cpp
index ad45cfcec..1ae027a78 100644
--- a/src/constructs/tss/tss.cpp
+++ b/src/constructs/tss/tss.cpp
@@ -192,8 +192,8 @@ RTSS_Share::reconstruct(const std::vector<RTSS_Share>& shares)
       if(shares[i].size() < RTSS_HEADER_SIZE)
          throw Decoding_Error("Missing or malformed RTSS header");
 
-      if(!same_mem(shares[0].contents.begin(),
-                   shares[i].contents.begin(), RTSS_HEADER_SIZE))
+      if(!same_mem(&shares[0].contents[0],
+                   &shares[i].contents[0], RTSS_HEADER_SIZE))
          throw Decoding_Error("Different RTSS headers detected");
       }
 
@@ -250,7 +250,7 @@ RTSS_Share::reconstruct(const std::vector<RTSS_Share>& shares)
    hash->update(secret, secret_len);
    SecureVector<byte> hash_check = hash->final();
 
-   if(!same_mem(hash_check.begin(), secret + secret_len, hash->OUTPUT_LENGTH))
+   if(!same_mem(&hash_check[0], secret + secret_len, hash->OUTPUT_LENGTH))
       throw Decoding_Error("RTSS hash check failed");
 
    return SecureVector<byte>(secret, secret_len);
diff --git a/src/entropy/cryptoapi_rng/es_capi.cpp b/src/entropy/cryptoapi_rng/es_capi.cpp
index 367166c62..f3a94ad34 100644
--- a/src/entropy/cryptoapi_rng/es_capi.cpp
+++ b/src/entropy/cryptoapi_rng/es_capi.cpp
@@ -61,11 +61,11 @@ void Win32_CAPI_EntropySource::poll(Entropy_Accumulator& accum)
       {
       CSP_Handle csp(prov_types[j]);
 
-      u32bit got = csp.gen_random(io_buffer.begin(), io_buffer.size());
+      u32bit got = csp.gen_random(&io_buffer[0], io_buffer.size());
 
       if(got)
          {
-         accum.add(io_buffer.begin(), io_buffer.size(), 8);
+         accum.add(&io_buffer[0], io_buffer.size(), 8);
          break;
          }
       }
diff --git a/src/entropy/dev_random/dev_random.cpp b/src/entropy/dev_random/dev_random.cpp
index d0babfd1e..a942806d0 100644
--- a/src/entropy/dev_random/dev_random.cpp
+++ b/src/entropy/dev_random/dev_random.cpp
@@ -111,12 +111,12 @@ void Device_EntropySource::poll(Entropy_Accumulator& accum)
 
    for(size_t i = 0; i != devices.size(); ++i)
       {
-      u32bit got = devices[i].get(io_buffer.begin(), io_buffer.size(),
+      u32bit got = devices[i].get(&io_buffer[0], io_buffer.size(),
                                   read_wait_ms);
 
       if(got)
          {
-         accum.add(io_buffer.begin(), got, 8);
+         accum.add(&io_buffer[0], got, 8);
          break;
          }
       }
diff --git a/src/entropy/egd/es_egd.cpp b/src/entropy/egd/es_egd.cpp
index 29880a544..7efcf204d 100644
--- a/src/entropy/egd/es_egd.cpp
+++ b/src/entropy/egd/es_egd.cpp
@@ -143,11 +143,11 @@ void EGD_EntropySource::poll(Entropy_Accumulator& accum)
 
    for(size_t i = 0; i != sockets.size(); ++i)
       {
-      u32bit got = sockets[i].read(io_buffer.begin(), io_buffer.size());
+      u32bit got = sockets[i].read(&io_buffer[0], io_buffer.size());
 
       if(got)
          {
-         accum.add(io_buffer.begin(), got, 8);
+         accum.add(&io_buffer[0], got, 8);
          break;
          }
       }
diff --git a/src/entropy/proc_walk/es_ftw.cpp b/src/entropy/proc_walk/es_ftw.cpp
index 53e39d834..ce359f03f 100644
--- a/src/entropy/proc_walk/es_ftw.cpp
+++ b/src/entropy/proc_walk/es_ftw.cpp
@@ -146,11 +146,11 @@ void FTW_EntropySource::poll(Entropy_Accumulator& accum)
          break;
          }
 
-      ssize_t got = ::read(fd, io_buffer.begin(), io_buffer.size());
+      ssize_t got = ::read(fd, &io_buffer[0], io_buffer.size());
       ::close(fd);
 
       if(got > 0)
-         accum.add(io_buffer.begin(), got, .01);
+         accum.add(&io_buffer[0], got, .01);
 
       if(accum.polling_goal_achieved())
          break;
diff --git a/src/entropy/unix_procs/es_unix.cpp b/src/entropy/unix_procs/es_unix.cpp
index 5756f93dd..8c6e097c7 100644
--- a/src/entropy/unix_procs/es_unix.cpp
+++ b/src/entropy/unix_procs/es_unix.cpp
@@ -106,7 +106,7 @@ void Unix_EntropySource::poll(Entropy_Accumulator& accum)
          u32bit got_this_loop = pipe.read(io_buffer, io_buffer.size());
          got_from_src += got_this_loop;
 
-         accum.add(io_buffer.begin(), got_this_loop, .005);
+         accum.add(&io_buffer[0], got_this_loop, .005);
          }
 
       sources[j].working = (got_from_src >= MINIMAL_WORKING) ? true : false;
diff --git a/src/filters/data_src.cpp b/src/filters/data_src.cpp
index eceb0184a..073be3f47 100644
--- a/src/filters/data_src.cpp
+++ b/src/filters/data_src.cpp
@@ -128,7 +128,7 @@ u32bit DataSource_Stream::peek(byte out[], u32bit length, u32bit offset) const
    if(offset)
       {
       SecureVector<byte> buf(offset);
-      source.read(reinterpret_cast<char*>(buf.begin()), buf.size());
+      source.read(reinterpret_cast<char*>(&buf[0]), buf.size());
       if(source.bad())
          throw Stream_IO_Error("DataSource_Stream::peek: Source failure");
       got = source.gcount();
diff --git a/src/filters/filter.h b/src/filters/filter.h
index d5aa9725b..a0b2e1c7a 100644
--- a/src/filters/filter.h
+++ b/src/filters/filter.h
@@ -65,7 +65,7 @@ class BOTAN_DLL Filter
       /**
       * @param in some input for the filter
       */
-      void send(const MemoryRegion<byte>& in) { send(in.begin(), in.size()); }
+      void send(const MemoryRegion<byte>& in) { send(&in[0], in.size()); }
       Filter();
    private:
       Filter(const Filter&) {}
diff --git a/src/filters/modes/cts/cts.cpp b/src/filters/modes/cts/cts.cpp
index c404d8f33..fd118bc3b 100644
--- a/src/filters/modes/cts/cts.cpp
+++ b/src/filters/modes/cts/cts.cpp
@@ -88,7 +88,7 @@ void CTS_Encryption::write(const byte input[], u32bit length)
       }
    else
       {
-      copy_mem(buffer.begin(), buffer + cipher->BLOCK_SIZE, cipher->BLOCK_SIZE);
+      copy_mem(&buffer[0], buffer + cipher->BLOCK_SIZE, cipher->BLOCK_SIZE);
       position = cipher->BLOCK_SIZE;
       }
    buffer.copy(position, input, length);
@@ -191,7 +191,7 @@ void CTS_Decryption::write(const byte input[], u32bit length)
       }
    else
       {
-      copy_mem(buffer.begin(), buffer + cipher->BLOCK_SIZE, cipher->BLOCK_SIZE);
+      copy_mem(&buffer[0], buffer + cipher->BLOCK_SIZE, cipher->BLOCK_SIZE);
       position = cipher->BLOCK_SIZE;
       }
    buffer.copy(position, input, length);
diff --git a/src/filters/modes/xts/xts.cpp b/src/filters/modes/xts/xts.cpp
index 608c315ff..e40dd3cf5 100644
--- a/src/filters/modes/xts/xts.cpp
+++ b/src/filters/modes/xts/xts.cpp
@@ -98,7 +98,7 @@ void XTS_Encryption::set_iv(const InitializationVector& iv)
    for(u32bit i = 1; i < blocks_in_tweak; ++i)
       {
       tweak.copy(i*cipher->BLOCK_SIZE,
-                 tweak.begin() + (i-1)*cipher->BLOCK_SIZE,
+                 &tweak[(i-1)*cipher->BLOCK_SIZE],
                  cipher->BLOCK_SIZE);
 
       poly_double(&tweak[i*cipher->BLOCK_SIZE], cipher->BLOCK_SIZE);
@@ -158,7 +158,7 @@ void XTS_Encryption::buffered_block(const byte input[], u32bit length)
       for(u32bit i = 1; i < blocks_in_tweak; ++i)
          {
          tweak.copy(i*cipher->BLOCK_SIZE,
-                    tweak.begin() + (i-1)*cipher->BLOCK_SIZE,
+                    &tweak[(i-1)*cipher->BLOCK_SIZE],
                     cipher->BLOCK_SIZE);
 
          poly_double(&tweak[i*cipher->BLOCK_SIZE], cipher->BLOCK_SIZE);
@@ -270,7 +270,7 @@ void XTS_Decryption::set_iv(const InitializationVector& iv)
    for(u32bit i = 1; i < blocks_in_tweak; ++i)
       {
       tweak.copy(i*cipher->BLOCK_SIZE,
-                 tweak.begin() + (i-1)*cipher->BLOCK_SIZE,
+                 &tweak[(i-1)*cipher->BLOCK_SIZE],
                  cipher->BLOCK_SIZE);
 
       poly_double(&tweak[i*cipher->BLOCK_SIZE], cipher->BLOCK_SIZE);
@@ -331,7 +331,7 @@ void XTS_Decryption::buffered_block(const byte input[], u32bit input_length)
       for(u32bit i = 1; i < blocks_in_tweak; ++i)
          {
          tweak.copy(i*cipher->BLOCK_SIZE,
-                    tweak.begin() + (i-1)*cipher->BLOCK_SIZE,
+                    &tweak[(i-1)*cipher->BLOCK_SIZE],
                     cipher->BLOCK_SIZE);
 
          poly_double(&tweak[i*cipher->BLOCK_SIZE], cipher->BLOCK_SIZE);
diff --git a/src/filters/pipe.cpp b/src/filters/pipe.cpp
index 22718cd8c..cba5449de 100644
--- a/src/filters/pipe.cpp
+++ b/src/filters/pipe.cpp
@@ -127,7 +127,7 @@ void Pipe::process_msg(const byte input[], u32bit length)
 */
 void Pipe::process_msg(const MemoryRegion<byte>& input)
    {
-   process_msg(input.begin(), input.size());
+   process_msg(&input[0], input.size());
    }
 
 /*
diff --git a/src/filters/pipe_io.cpp b/src/filters/pipe_io.cpp
index c57be6d53..bf4a05642 100644
--- a/src/filters/pipe_io.cpp
+++ b/src/filters/pipe_io.cpp
@@ -19,7 +19,7 @@ std::ostream& operator<<(std::ostream& stream, Pipe& pipe)
    while(stream.good() && pipe.remaining())
       {
       u32bit got = pipe.read(buffer, buffer.size());
-      stream.write(reinterpret_cast<const char*>(buffer.begin()), got);
+      stream.write(reinterpret_cast<const char*>(&buffer[0]), got);
       }
    if(!stream.good())
       throw Stream_IO_Error("Pipe output operator (iostream) has failed");
@@ -34,7 +34,7 @@ std::istream& operator>>(std::istream& stream, Pipe& pipe)
    SecureVector<byte> buffer(DEFAULT_BUFFERSIZE);
    while(stream.good())
       {
-      stream.read(reinterpret_cast<char*>(buffer.begin()), buffer.size());
+      stream.read(reinterpret_cast<char*>(&buffer[0]), buffer.size());
       pipe.write(buffer, stream.gcount());
       }
    if(stream.bad() || (stream.fail() && !stream.eof()))
diff --git a/src/filters/pipe_rw.cpp b/src/filters/pipe_rw.cpp
index 20119c75b..ebbfb101a 100644
--- a/src/filters/pipe_rw.cpp
+++ b/src/filters/pipe_rw.cpp
@@ -43,7 +43,7 @@ void Pipe::write(const byte input[], u32bit length)
 */
 void Pipe::write(const MemoryRegion<byte>& input)
    {
-   write(input.begin(), input.size());
+   write(&input[0], input.size());
    }
 
 /*
@@ -125,7 +125,7 @@ std::string Pipe::read_all_as_string(message_id msg)
       u32bit got = read(buffer, buffer.size(), msg);
       if(got == 0)
          break;
-      str.append(reinterpret_cast<const char*>(buffer.begin()), got);
+      str.append(reinterpret_cast<const char*>(&buffer[0]), got);
       }
 
    return str;
diff --git a/src/hash/bmw/bmw_512.cpp b/src/hash/bmw/bmw_512.cpp
index a9b580ca6..f511e516b 100644
--- a/src/hash/bmw/bmw_512.cpp
+++ b/src/hash/bmw/bmw_512.cpp
@@ -143,7 +143,7 @@ void BMW_512::compress_n(const byte input[], u32bit blocks)
    {
    for(u32bit i = 0; i != blocks; ++i)
       {
-      load_le(M.begin(), input, M.size());
+      load_le(&M[0], input, M.size());
 
       BMW_512_compress(H, M, Q);
 
diff --git a/src/hash/gost_3411/gost_3411.cpp b/src/hash/gost_3411/gost_3411.cpp
index 7e6fd8fac..ad874fe8a 100644
--- a/src/hash/gost_3411/gost_3411.cpp
+++ b/src/hash/gost_3411/gost_3411.cpp
@@ -45,7 +45,7 @@ void GOST_34_11::add_data(const byte input[], u32bit length)
 
       if(position + length >= HASH_BLOCK_SIZE)
          {
-         compress_n(buffer.begin(), 1);
+         compress_n(&buffer[0], 1);
          input += (HASH_BLOCK_SIZE - position);
          length -= (HASH_BLOCK_SIZE - position);
          position = 0;
@@ -219,7 +219,7 @@ void GOST_34_11::final_result(byte out[])
    {
    if(position)
       {
-      clear_mem(buffer.begin() + position, buffer.size() - position);
+      clear_mem(&buffer[0] + position, buffer.size() - position);
       compress_n(buffer, 1);
       }
 
@@ -232,7 +232,7 @@ void GOST_34_11::final_result(byte out[])
    compress_n(length_buf, 1);
    compress_n(sum_buf, 1);
 
-   copy_mem(out, hash.begin(), 32);
+   copy_mem(out, &hash[0], 32);
 
    clear();
    }
diff --git a/src/hash/has160/has160.cpp b/src/hash/has160/has160.cpp
index fd39e7ea0..5786ae0ee 100644
--- a/src/hash/has160/has160.cpp
+++ b/src/hash/has160/has160.cpp
@@ -67,7 +67,7 @@ void HAS_160::compress_n(const byte input[], u32bit blocks)
 
    for(u32bit i = 0; i != blocks; ++i)
       {
-      load_le(X.begin(), input, 16);
+      load_le(&X[0], input, 16);
 
       X[16] = X[ 0] ^ X[ 1] ^ X[ 2] ^ X[ 3];
       X[17] = X[ 4] ^ X[ 5] ^ X[ 6] ^ X[ 7];
diff --git a/src/hash/md2/md2.cpp b/src/hash/md2/md2.cpp
index b3ccae6df..376a95e93 100644
--- a/src/hash/md2/md2.cpp
+++ b/src/hash/md2/md2.cpp
@@ -66,7 +66,7 @@ void MD2::add_data(const byte input[], u32bit length)
    buffer.copy(position, input, length);
    if(position + length >= HASH_BLOCK_SIZE)
       {
-      hash(buffer.begin());
+      hash(&buffer[0]);
       input += (HASH_BLOCK_SIZE - position);
       length -= (HASH_BLOCK_SIZE - position);
       while(length >= HASH_BLOCK_SIZE)
@@ -90,7 +90,7 @@ void MD2::final_result(byte output[])
       buffer[j] = static_cast<byte>(HASH_BLOCK_SIZE - position);
    hash(buffer);
    hash(checksum);
-   copy_mem(output, X.begin(), OUTPUT_LENGTH);
+   copy_mem(output, &X[0], OUTPUT_LENGTH);
    clear();
    }
 
diff --git a/src/hash/md4/md4.cpp b/src/hash/md4/md4.cpp
index edba1d08a..326ca8eba 100644
--- a/src/hash/md4/md4.cpp
+++ b/src/hash/md4/md4.cpp
@@ -51,7 +51,7 @@ void MD4::compress_n(const byte input[], u32bit blocks)
 
    for(u32bit i = 0; i != blocks; ++i)
       {
-      load_le(M.begin(), input, M.size());
+      load_le(&M[0], input, M.size());
 
       FF(A,B,C,D,M[ 0], 3);   FF(D,A,B,C,M[ 1], 7);
       FF(C,D,A,B,M[ 2],11);   FF(B,C,D,A,M[ 3],19);
diff --git a/src/hash/md5/md5.cpp b/src/hash/md5/md5.cpp
index 104155e9d..b1745b944 100644
--- a/src/hash/md5/md5.cpp
+++ b/src/hash/md5/md5.cpp
@@ -64,7 +64,7 @@ void MD5::compress_n(const byte input[], u32bit blocks)
 
    for(u32bit i = 0; i != blocks; ++i)
       {
-      load_le(M.begin(), input, M.size());
+      load_le(&M[0], input, M.size());
 
       FF(A,B,C,D,M[ 0], 7,0xD76AA478);   FF(D,A,B,C,M[ 1],12,0xE8C7B756);
       FF(C,D,A,B,M[ 2],17,0x242070DB);   FF(B,C,D,A,M[ 3],22,0xC1BDCEEE);
diff --git a/src/hash/mdx_hash/mdx_hash.cpp b/src/hash/mdx_hash/mdx_hash.cpp
index ffca0d93b..69341c53f 100644
--- a/src/hash/mdx_hash/mdx_hash.cpp
+++ b/src/hash/mdx_hash/mdx_hash.cpp
@@ -47,7 +47,7 @@ void MDx_HashFunction::add_data(const byte input[], u32bit length)
 
       if(position + length >= HASH_BLOCK_SIZE)
          {
-         compress_n(buffer.begin(), 1);
+         compress_n(&buffer[0], 1);
          input += (HASH_BLOCK_SIZE - position);
          length -= (HASH_BLOCK_SIZE - position);
          position = 0;
diff --git a/src/hash/rmd128/rmd128.cpp b/src/hash/rmd128/rmd128.cpp
index 9e0f6701e..3e7eb9143 100644
--- a/src/hash/rmd128/rmd128.cpp
+++ b/src/hash/rmd128/rmd128.cpp
@@ -68,7 +68,7 @@ void RIPEMD_128::compress_n(const byte input[], u32bit blocks)
 
    for(u32bit i = 0; i != blocks; ++i)
       {
-      load_le(M.begin(), input, M.size());
+      load_le(&M[0], input, M.size());
 
       u32bit A1 = digest[0], A2 = A1, B1 = digest[1], B2 = B1,
              C1 = digest[2], C2 = C1, D1 = digest[3], D2 = D1;
diff --git a/src/hash/rmd160/rmd160.cpp b/src/hash/rmd160/rmd160.cpp
index 4975814f4..f832d4ec1 100644
--- a/src/hash/rmd160/rmd160.cpp
+++ b/src/hash/rmd160/rmd160.cpp
@@ -82,7 +82,7 @@ void RIPEMD_160::compress_n(const byte input[], u32bit blocks)
 
    for(u32bit i = 0; i != blocks; ++i)
       {
-      load_le(M.begin(), input, M.size());
+      load_le(&M[0], input, M.size());
 
       u32bit A1 = digest[0], A2 = A1, B1 = digest[1], B2 = B1,
              C1 = digest[2], C2 = C1, D1 = digest[3], D2 = D1,
diff --git a/src/hash/sha1/sha160.cpp b/src/hash/sha1/sha160.cpp
index 1e57f0cf4..0b3d7c346 100644
--- a/src/hash/sha1/sha160.cpp
+++ b/src/hash/sha1/sha160.cpp
@@ -61,7 +61,7 @@ void SHA_160::compress_n(const byte input[], u32bit blocks)
 
    for(u32bit i = 0; i != blocks; ++i)
       {
-      load_be(W.begin(), input, 16);
+      load_be(&W[0], input, 16);
 
       for(u32bit j = 16; j != 80; j += 8)
          {
diff --git a/src/hash/sha2/sha2_32.cpp b/src/hash/sha2/sha2_32.cpp
index a18a4d8c4..acd06061e 100644
--- a/src/hash/sha2/sha2_32.cpp
+++ b/src/hash/sha2/sha2_32.cpp
@@ -56,7 +56,7 @@ void sha2_32_compress(MemoryRegion<u32bit>& W,
 
    for(u32bit i = 0; i != blocks; ++i)
       {
-      load_be(W.begin(), input, 16);
+      load_be(&W[0], input, 16);
 
       for(u32bit j = 16; j != 64; j += 8)
          {
diff --git a/src/hash/sha2/sha2_64.cpp b/src/hash/sha2/sha2_64.cpp
index aecf9a0db..5ca78173c 100644
--- a/src/hash/sha2/sha2_64.cpp
+++ b/src/hash/sha2/sha2_64.cpp
@@ -55,7 +55,7 @@ void sha2_64_compress(MemoryRegion<u64bit>& W,
 
    for(u32bit i = 0; i != blocks; ++i)
       {
-      load_be(W.begin(), input, 16);
+      load_be(&W[0], input, 16);
 
       for(u32bit j = 16; j != 80; j += 8)
          {
diff --git a/src/hash/skein/skein_512.cpp b/src/hash/skein/skein_512.cpp
index 1fdd9fbf6..dabaa5da2 100644
--- a/src/hash/skein/skein_512.cpp
+++ b/src/hash/skein/skein_512.cpp
@@ -240,7 +240,7 @@ void Skein_512::final_result(byte out[])
       {
       const u32bit to_proc = std::min<u32bit>(out_bytes, 64);
 
-      H_out.copy(H.begin(), 8);
+      H_out.copy(&H[0], 8);
 
       reset_tweak(T, SKEIN_OUTPUT, true);
       ubi_512(H_out, T, counter, sizeof(counter));
diff --git a/src/hash/tiger/tiger.cpp b/src/hash/tiger/tiger.cpp
index 1812abf12..dd41841c9 100644
--- a/src/hash/tiger/tiger.cpp
+++ b/src/hash/tiger/tiger.cpp
@@ -38,7 +38,7 @@ void Tiger::compress_n(const byte input[], u32bit blocks)
 
    for(u32bit i = 0; i != blocks; ++i)
       {
-      load_le(X.begin(), input, X.size());
+      load_le(&X[0], input, X.size());
 
       pass(A, B, C, X, 5); mix(X);
       pass(C, A, B, X, 7); mix(X);
diff --git a/src/hash/whirlpool/whrlpool.cpp b/src/hash/whirlpool/whrlpool.cpp
index 6f62695c8..fcd244ce2 100644
--- a/src/hash/whirlpool/whrlpool.cpp
+++ b/src/hash/whirlpool/whrlpool.cpp
@@ -25,7 +25,7 @@ void Whirlpool::compress_n(const byte in[], u32bit blocks)
 
    for(u32bit i = 0; i != blocks; ++i)
       {
-      load_be(M.begin(), in, M.size());
+      load_be(&M[0], in, M.size());
 
       u64bit K0, K1, K2, K3, K4, K5, K6, K7;
       K0 = digest[0]; K1 = digest[1]; K2 = digest[2]; K3 = digest[3];
diff --git a/src/kdf/kdf.cpp b/src/kdf/kdf.cpp
index 4be8475df..86f5f2476 100644
--- a/src/kdf/kdf.cpp
+++ b/src/kdf/kdf.cpp
@@ -28,7 +28,7 @@ SecureVector<byte> KDF::derive_key(u32bit key_len,
                                    const MemoryRegion<byte>& secret,
                                    const byte salt[], u32bit salt_len) const
    {
-   return derive_key(key_len, secret.begin(), secret.size(),
+   return derive_key(key_len, &secret[0], secret.size(),
                      salt, salt_len);
    }
 
@@ -39,8 +39,8 @@ SecureVector<byte> KDF::derive_key(u32bit key_len,
                                    const MemoryRegion<byte>& secret,
                                    const MemoryRegion<byte>& salt) const
    {
-   return derive_key(key_len, secret.begin(), secret.size(),
-                     salt.begin(), salt.size());
+   return derive_key(key_len, &secret[0], secret.size(),
+                     &salt[0], salt.size());
    }
 
 /*
diff --git a/src/kdf/mgf1/mgf1.cpp b/src/kdf/mgf1/mgf1.cpp
index 340e87a7c..509a411fa 100644
--- a/src/kdf/mgf1/mgf1.cpp
+++ b/src/kdf/mgf1/mgf1.cpp
@@ -30,7 +30,7 @@ void MGF1::mask(const byte in[], u32bit in_len, byte out[],
       SecureVector<byte> buffer = hash->final();
 
       u32bit xored = std::min(buffer.size(), out_len);
-      xor_buf(out, buffer.begin(), xored);
+      xor_buf(out, &buffer[0], xored);
       out += xored;
       out_len -= xored;
 
diff --git a/src/mac/cbc_mac/cbc_mac.cpp b/src/mac/cbc_mac/cbc_mac.cpp
index 206bce55c..387737eac 100644
--- a/src/mac/cbc_mac/cbc_mac.cpp
+++ b/src/mac/cbc_mac/cbc_mac.cpp
@@ -46,7 +46,7 @@ void CBC_MAC::final_result(byte mac[])
    if(position)
       e->encrypt(state);
 
-   copy_mem(mac, state.begin(), state.size());
+   copy_mem(mac, &state[0], state.size());
    zeroise(state);
    position = 0;
    }
diff --git a/src/math/bigint/big_io.cpp b/src/math/bigint/big_io.cpp
index b50fcceff..f3e7fb861 100644
--- a/src/math/bigint/big_io.cpp
+++ b/src/math/bigint/big_io.cpp
@@ -31,7 +31,7 @@ std::ostream& operator<<(std::ostream& stream, const BigInt& n)
       u32bit skip = 0;
       while(buffer[skip] == '0' && skip < buffer.size())
          ++skip;
-      stream.write(reinterpret_cast<const char*>(buffer.begin()) + skip,
+      stream.write(reinterpret_cast<const char*>(&buffer[0]) + skip,
                    buffer.size() - skip);
       }
    if(!stream.good())
diff --git a/src/math/bigint/big_ops2.cpp b/src/math/bigint/big_ops2.cpp
index 193c00e32..554fb1793 100644
--- a/src/math/bigint/big_ops2.cpp
+++ b/src/math/bigint/big_ops2.cpp
@@ -32,7 +32,7 @@ BigInt& BigInt::operator+=(const BigInt& y)
          {
          SecureVector<word> z(reg_size - 1);
          bigint_sub3(z, y.data(), reg_size - 1, data(), x_sw);
-         copy_mem(get_reg().begin(), z.begin(), z.size());
+         copy_mem(&reg[0], &z[0], z.size());
          set_sign(y.sign());
          }
       else if(relative_size == 0)
diff --git a/src/math/bigint/bigint.h b/src/math/bigint/bigint.h
index 9ce71aeca..cd6997698 100644
--- a/src/math/bigint/bigint.h
+++ b/src/math/bigint/bigint.h
@@ -291,7 +291,7 @@ class BOTAN_DLL BigInt
      */
      u32bit sig_words() const
         {
-        const word* x = reg.begin();
+        const word* x = &reg[0];
         u32bit sig = reg.size();
 
         while(sig && (x[sig-1] == 0))
@@ -316,7 +316,7 @@ class BOTAN_DLL BigInt
      * @result a pointer to the start of the internal register of
      * the integer value
      */
-     const word* data() const { return reg.begin(); }
+     const word* data() const { return &reg[0]; }
 
      /**
      * return a reference to the internal register containing the value
diff --git a/src/math/numbertheory/point_gfp.cpp b/src/math/numbertheory/point_gfp.cpp
index 93e3392ea..b593443f7 100644
--- a/src/math/numbertheory/point_gfp.cpp
+++ b/src/math/numbertheory/point_gfp.cpp
@@ -56,7 +56,7 @@ void PointGFp::monty_mult(BigInt& z,
                      p.data(), p_size, p_dash);
 
    z.get_reg().resize(p_size);
-   copy_mem(z.get_reg().begin(), &workspace[p_size], p_size);
+   copy_mem(&z.get_reg()[0], &workspace[p_size], p_size);
    }
 
 // Montgomery squaring
@@ -82,7 +82,7 @@ void PointGFp::monty_sqr(BigInt& z, const BigInt& x,
                      p.data(), p_size, p_dash);
 
    z.get_reg().resize(p_size);
-   copy_mem(z.get_reg().begin(), &workspace[p_size], p_size);
+   copy_mem(&z.get_reg()[0], &workspace[p_size], p_size);
    }
 
 // Point addition
@@ -475,8 +475,8 @@ SecureVector<byte> EC2OSP(const PointGFp& point, byte format)
       SecureVector<byte> result(2*p_bytes+1);
       result[0] = 4;
 
-      result.copy(1, bX.begin(), p_bytes);
-      result.copy(p_bytes+1, bY.begin(), p_bytes);
+      result.copy(1, &bX[0], p_bytes);
+      result.copy(p_bytes+1, &bY[0], p_bytes);
       return result;
       }
    else if(format == PointGFp::COMPRESSED)
@@ -484,7 +484,7 @@ SecureVector<byte> EC2OSP(const PointGFp& point, byte format)
       SecureVector<byte> result(p_bytes+1);
       result[0] = 2;
 
-      result.copy(1, bX.begin(), bX.size());
+      result.copy(1, &bX[0], bX.size());
 
       if(y.get_bit(0))
          result[0] |= 1;
@@ -496,8 +496,8 @@ SecureVector<byte> EC2OSP(const PointGFp& point, byte format)
       SecureVector<byte> result(2*p_bytes+1);
       result[0] = 6;
 
-      result.copy(1, bX.begin(), bX.size());
-      result.copy(p_bytes+1, bY.begin(), bY.size());
+      result.copy(1, &bX[0], bX.size());
+      result.copy(p_bytes+1, &bY[0], bY.size());
 
       if(y.get_bit(0))
          result[0] |= 1;
diff --git a/src/math/numbertheory/powm_mnt.cpp b/src/math/numbertheory/powm_mnt.cpp
index 80582eaa8..b565d7a21 100644
--- a/src/math/numbertheory/powm_mnt.cpp
+++ b/src/math/numbertheory/powm_mnt.cpp
@@ -20,7 +20,7 @@ inline void montgomery_reduce(BigInt& out, MemoryRegion<word>& z_buf,
                               const BigInt& x_bn, u32bit x_size, word u)
    {
    const word* x = x_bn.data();
-   word* z = z_buf.begin();
+   word* z = &z_buf[0];
    u32bit z_size = z_buf.size();
 
    bigint_monty_redc(z, z_size, x, x_size, u);
@@ -52,7 +52,7 @@ void Montgomery_Exponentiator::set_base(const BigInt& base)
    SecureVector<word> workspace(z.size());
 
    g[0] = (base >= modulus) ? (base % modulus) : base;
-   bigint_mul(z.begin(), z.size(), workspace,
+   bigint_mul(&z[0], z.size(), workspace,
               g[0].data(), g[0].size(), g[0].sig_words(),
               R2.data(), R2.size(), R2.sig_words());
 
@@ -67,7 +67,7 @@ void Montgomery_Exponentiator::set_base(const BigInt& base)
       const u32bit y_sig = y.sig_words();
 
       zeroise(z);
-      bigint_mul(z.begin(), z.size(), workspace,
+      bigint_mul(&z[0], z.size(), workspace,
                  x.data(), x.size(), x_sig,
                  y.data(), y.size(), y_sig);
 
@@ -91,7 +91,7 @@ BigInt Montgomery_Exponentiator::execute() const
       for(u32bit k = 0; k != window_bits; ++k)
          {
          zeroise(z);
-         bigint_sqr(z.begin(), z.size(), workspace,
+         bigint_sqr(&z[0], z.size(), workspace,
                     x.data(), x.size(), x.sig_words());
 
          montgomery_reduce(x, z, modulus, mod_words, mod_prime);
@@ -103,7 +103,7 @@ BigInt Montgomery_Exponentiator::execute() const
          const BigInt& y = g[nibble-1];
 
          zeroise(z);
-         bigint_mul(z.begin(), z.size(), workspace,
+         bigint_mul(&z[0], z.size(), workspace,
                     x.data(), x.size(), x.sig_words(),
                     y.data(), y.size(), y.sig_words());
 
diff --git a/src/pbkdf/pbkdf2/pbkdf2.cpp b/src/pbkdf/pbkdf2/pbkdf2.cpp
index 6f6a514f8..d234fa7f0 100644
--- a/src/pbkdf/pbkdf2/pbkdf2.cpp
+++ b/src/pbkdf/pbkdf2/pbkdf2.cpp
@@ -35,7 +35,7 @@ OctetString PKCS5_PBKDF2::derive_key(u32bit key_len,
 
    SecureVector<byte> key(key_len);
 
-   byte* T = key.begin();
+   byte* T = &key[0];
 
    u32bit counter = 1;
    while(key_len)
diff --git a/src/pk_pad/emsa4/emsa4.cpp b/src/pk_pad/emsa4/emsa4.cpp
index df4005aad..41b1e6971 100644
--- a/src/pk_pad/emsa4/emsa4.cpp
+++ b/src/pk_pad/emsa4/emsa4.cpp
@@ -94,8 +94,8 @@ bool EMSA4::verify(const MemoryRegion<byte>& const_coded,
    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);
+   SecureVector<byte> DB(&coded[0], 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;
diff --git a/src/rng/hmac_rng/hmac_rng.cpp b/src/rng/hmac_rng/hmac_rng.cpp
index b9bd65ae1..eb67c7f4e 100644
--- a/src/rng/hmac_rng/hmac_rng.cpp
+++ b/src/rng/hmac_rng/hmac_rng.cpp
@@ -48,7 +48,7 @@ void HMAC_RNG::randomize(byte out[], u32bit length)
 
       const u32bit copied = std::min(K.size(), length);
 
-      copy_mem(out, K.begin(), copied);
+      copy_mem(out, &K[0], copied);
       out += copied;
       length -= copied;
       }
diff --git a/src/rng/randpool/randpool.cpp b/src/rng/randpool/randpool.cpp
index fb8dfcd09..b5e2e2748 100644
--- a/src/rng/randpool/randpool.cpp
+++ b/src/rng/randpool/randpool.cpp
@@ -38,7 +38,7 @@ void Randpool::randomize(byte out[], u32bit length)
    while(length)
       {
       const u32bit copied = std::min(length, buffer.size());
-      copy_mem(out, buffer.begin(), copied);
+      copy_mem(out, &buffer[0], copied);
       out += copied;
       length -= copied;
       update_buffer();
diff --git a/src/ssl/cert_req.cpp b/src/ssl/cert_req.cpp
index d2f08f2a8..7a7e6eed9 100644
--- a/src/ssl/cert_req.cpp
+++ b/src/ssl/cert_req.cpp
@@ -76,7 +76,7 @@ void Certificate_Req::deserialize(const MemoryRegion<byte>& buf)
    if(buf.size() != names_size + types_size + 3)
       throw Decoding_Error("Certificate_Req: Bad certificate request");
 
-   BER_Decoder decoder(buf.begin() + types_size + 3, names_size);
+   BER_Decoder decoder(&buf[types_size + 3], names_size);
 
    while(decoder.more_items())
       {
diff --git a/src/ssl/handshake_hash.h b/src/ssl/handshake_hash.h
index 8e068f3de..df50e4dfe 100644
--- a/src/ssl/handshake_hash.h
+++ b/src/ssl/handshake_hash.h
@@ -22,8 +22,10 @@ class BOTAN_DLL HandshakeHash
    public:
       void update(const byte in[], u32bit length)
          { data.append(in, length); }
+
       void update(const MemoryRegion<byte>& in)
-         { update(in.begin(), in.size()); }
+         { update(&in[0], in.size()); }
+
       void update(byte in)
          { update(&in, 1); }
 
diff --git a/src/ssl/rec_read.cpp b/src/ssl/rec_read.cpp
index 895026431..86b976417 100644
--- a/src/ssl/rec_read.cpp
+++ b/src/ssl/rec_read.cpp
@@ -217,7 +217,7 @@ u32bit Record_Reader::get_record(byte& msg_type,
       throw Decoding_Error("Record_Reader: Record truncated");
 
    const u32bit mac_offset = plaintext.size() - (mac_size + pad_size);
-   SecureVector<byte> recieved_mac(plaintext.begin() + mac_offset,
+   SecureVector<byte> recieved_mac(&plaintext[mac_offset],
                                    mac_size);
 
    const u16bit plain_length = plaintext.size() - (mac_size + pad_size + iv_size);
diff --git a/src/ssl/rec_wri.cpp b/src/ssl/rec_wri.cpp
index 40dd45219..d983fd363 100644
--- a/src/ssl/rec_wri.cpp
+++ b/src/ssl/rec_wri.cpp
@@ -160,7 +160,7 @@ void Record_Writer::send(byte type, const byte input[], u32bit length)
 */
 void Record_Writer::flush()
    {
-   const byte* buf_ptr = buffer.begin();
+   const byte* buf_ptr = &buffer[0];
    u32bit offset = 0;
 
    while(offset != buf_pos)
diff --git a/src/stream/arc4/arc4.cpp b/src/stream/arc4/arc4.cpp
index a3a2f9a65..90f0f0904 100644
--- a/src/stream/arc4/arc4.cpp
+++ b/src/stream/arc4/arc4.cpp
@@ -18,13 +18,13 @@ void ARC4::cipher(const byte in[], byte out[], u32bit length)
    {
    while(length >= buffer.size() - position)
       {
-      xor_buf(out, in, buffer.begin() + position, buffer.size() - position);
+      xor_buf(out, in, &buffer[position], buffer.size() - position);
       length -= (buffer.size() - position);
       in += (buffer.size() - position);
       out += (buffer.size() - position);
       generate();
       }
-   xor_buf(out, in, buffer.begin() + position, length);
+   xor_buf(out, in, &buffer[position], length);
    position += length;
    }
 
diff --git a/src/stream/ctr/ctr.cpp b/src/stream/ctr/ctr.cpp
index cd1b1b7fb..6162a76a0 100644
--- a/src/stream/ctr/ctr.cpp
+++ b/src/stream/ctr/ctr.cpp
@@ -71,13 +71,13 @@ void CTR_BE::cipher(const byte in[], byte out[], u32bit length)
    {
    while(length >= buffer.size() - position)
       {
-      xor_buf(out, in, buffer.begin() + position, buffer.size() - position);
+      xor_buf(out, in, &buffer[position], buffer.size() - position);
       length -= (buffer.size() - position);
       in += (buffer.size() - position);
       out += (buffer.size() - position);
       increment_counter();
       }
-   xor_buf(out, in, buffer.begin() + position, length);
+   xor_buf(out, in, &buffer[position], length);
    position += length;
    }
 
@@ -100,7 +100,8 @@ void CTR_BE::set_iv(const byte iv[], u32bit iv_len)
    for(u32bit i = 1; i != PARALLEL_BLOCKS; ++i)
       {
       counter.copy(i*BLOCK_SIZE,
-                   counter.begin() + (i-1)*BLOCK_SIZE, BLOCK_SIZE);
+                   &counter[(i-1)*BLOCK_SIZE],
+                   BLOCK_SIZE);
 
       for(s32bit j = BLOCK_SIZE - 1; j >= 0; --j)
          if(++counter[i*BLOCK_SIZE+j])
diff --git a/src/stream/ofb/ofb.cpp b/src/stream/ofb/ofb.cpp
index 332673153..6fc8e4b68 100644
--- a/src/stream/ofb/ofb.cpp
+++ b/src/stream/ofb/ofb.cpp
@@ -68,14 +68,14 @@ void OFB::cipher(const byte in[], byte out[], u32bit length)
    {
    while(length >= buffer.size() - position)
       {
-      xor_buf(out, in, buffer.begin() + position, buffer.size() - position);
+      xor_buf(out, in, &buffer[position], buffer.size() - position);
       length -= (buffer.size() - position);
       in += (buffer.size() - position);
       out += (buffer.size() - position);
       permutation->encrypt(buffer);
       position = 0;
       }
-   xor_buf(out, in, buffer.begin() + position, length);
+   xor_buf(out, in, &buffer[position], length);
    position += length;
    }
 
diff --git a/src/stream/turing/turing.cpp b/src/stream/turing/turing.cpp
index bfb2166d8..c53b666ad 100644
--- a/src/stream/turing/turing.cpp
+++ b/src/stream/turing/turing.cpp
@@ -39,13 +39,13 @@ void Turing::cipher(const byte in[], byte out[], u32bit length)
    {
    while(length >= buffer.size() - position)
       {
-      xor_buf(out, in, buffer.begin() + position, buffer.size() - position);
+      xor_buf(out, in, &buffer[position], buffer.size() - position);
       length -= (buffer.size() - position);
       in += (buffer.size() - position);
       out += (buffer.size() - position);
       generate();
       }
-   xor_buf(out, in, buffer.begin() + position, length);
+   xor_buf(out, in, &buffer[position], length);
    position += length;
    }
 
diff --git a/src/sym_algo/symkey.cpp b/src/sym_algo/symkey.cpp
index a04f29181..65eb268cb 100644
--- a/src/sym_algo/symkey.cpp
+++ b/src/sym_algo/symkey.cpp
@@ -92,7 +92,7 @@ std::string OctetString::as_string() const
 OctetString& OctetString::operator^=(const OctetString& k)
    {
    if(&k == this) { zeroise(bits); return (*this); }
-   xor_buf(bits.begin(), k.begin(), std::min(length(), k.length()));
+   xor_buf(&bits[0], k.begin(), std::min(length(), k.length()));
    return (*this);
    }
 
diff --git a/src/sym_algo/symkey.h b/src/sym_algo/symkey.h
index 07b588329..154ae59da 100644
--- a/src/sym_algo/symkey.h
+++ b/src/sym_algo/symkey.h
@@ -32,12 +32,12 @@ class BOTAN_DLL OctetString
       /**
       * @return start of this string
       */
-      const byte* begin() const { return bits.begin(); }
+      const byte* begin() const { return &bits[0]; }
 
       /**
       * @return end of this string
       */
-      const byte* end() const   { return bits.end(); }
+      const byte* end() const   { return &bits[bits.size()]; }
 
       /**
       * @return this encoded as hex