merge of 'bf0e5684d8ba5fb0a21cdcd11d26995cbb250c4a'

     and 'e30a741f6014987e9683842ede22c44b2db03c56'

31 files changed, 97 insertions, 153 deletions

diff --git a/checks/block.cpp b/checks/block.cpp
index 3cd41e63a..c90e3e499 100644
--- a/checks/block.cpp
+++ b/checks/block.cpp
@@ -89,7 +89,7 @@ void ECB_Encryption_ErrorCheck::end_msg()
       }
 
    if(position)
-      throw Exception("ECB: input was not in full blocks");
+      throw Encoding_Error("ECB: input was not in full blocks");
    }
 
 Filter* lookup_block(const std::string& algname, const std::string& key)
diff --git a/checks/pk.cpp b/checks/pk.cpp
index e6f4d4f48..9c243f1cf 100644
--- a/checks/pk.cpp
+++ b/checks/pk.cpp
@@ -172,7 +172,7 @@ u32bit validate_rsa_enc_pkcs8(const std::string& algo,
                               RandomNumberGenerator& rng)
    {
    if(str.size() != 4 && str.size() != 5)
-      throw Exception("Invalid input from pk_valid.dat");
+      throw std::runtime_error("Invalid input from pk_valid.dat");
 
 
 #if defined(BOTAN_HAS_RSA)
@@ -210,7 +210,7 @@ u32bit validate_rsa_enc(const std::string& algo,
                         RandomNumberGenerator& rng)
    {
    if(str.size() != 6)
-      throw Exception("Invalid input from pk_valid.dat");
+      throw std::runtime_error("Invalid input from pk_valid.dat");
 
 
 #if defined(BOTAN_HAS_RSA)
@@ -238,7 +238,7 @@ u32bit validate_elg_enc(const std::string& algo,
                         RandomNumberGenerator& rng)
    {
    if(str.size() != 6 && str.size() != 7)
-      throw Exception("Invalid input from pk_valid.dat");
+      throw std::runtime_error("Invalid input from pk_valid.dat");
 
 
 #if defined(BOTAN_HAS_ELGAMAL)
@@ -270,7 +270,7 @@ u32bit validate_rsa_sig(const std::string& algo,
                         RandomNumberGenerator& rng)
    {
    if(str.size() != 6)
-      throw Exception("Invalid input from pk_valid.dat");
+      throw std::runtime_error("Invalid input from pk_valid.dat");
 
 
 #if defined(BOTAN_HAS_RSA)
@@ -296,7 +296,7 @@ u32bit validate_rsa_ver(const std::string& algo,
                         const std::vector<std::string>& str)
    {
    if(str.size() != 5) /* is actually 4, parse() adds an extra empty one */
-      throw Exception("Invalid input from pk_valid.dat");
+      throw std::runtime_error("Invalid input from pk_valid.dat");
 
 #if defined(BOTAN_HAS_RSA)
    RSA_PublicKey key(to_bigint(str[1]), to_bigint(str[0]));
@@ -320,7 +320,7 @@ u32bit validate_rsa_ver_x509(const std::string& algo,
                              const std::vector<std::string>& str)
    {
    if(str.size() != 5) /* is actually 3, parse() adds extra empty ones */
-      throw Exception("Invalid input from pk_valid.dat");
+      throw std::runtime_error("Invalid input from pk_valid.dat");
 
 #if defined(BOTAN_HAS_RSA)
    DataSource_Memory keysource(reinterpret_cast<const byte*>(str[0].c_str()),
@@ -352,7 +352,7 @@ u32bit validate_rw_ver(const std::string& algo,
                        const std::vector<std::string>& str)
    {
    if(str.size() != 5)
-      throw Exception("Invalid input from pk_valid.dat");
+      throw std::runtime_error("Invalid input from pk_valid.dat");
 
 
 
@@ -379,7 +379,7 @@ u32bit validate_rw_sig(const std::string& algo,
                        RandomNumberGenerator& rng)
    {
    if(str.size() != 6)
-      throw Exception("Invalid input from pk_valid.dat");
+      throw std::runtime_error("Invalid input from pk_valid.dat");
 
 
 #if defined(BOTAN_HAS_RW)
@@ -405,7 +405,7 @@ u32bit validate_dsa_sig(const std::string& algo,
                         RandomNumberGenerator& rng)
    {
    if(str.size() != 4 && str.size() != 5)
-      throw Exception("Invalid input from pk_valid.dat");
+      throw std::runtime_error("Invalid input from pk_valid.dat");
 
    std::string pass;
    if(str.size() == 5) pass = str[4];
@@ -442,7 +442,7 @@ u32bit validate_dsa_ver(const std::string& algo,
                         const std::vector<std::string>& str)
    {
    if(str.size() != 5) /* is actually 3, parse() adds extra empty ones */
-      throw Exception("Invalid input from pk_valid.dat");
+      throw std::runtime_error("Invalid input from pk_valid.dat");
 
    DataSource_Memory keysource(reinterpret_cast<const byte*>(str[0].c_str()),
                                str[0].length());
@@ -476,7 +476,7 @@ u32bit validate_nr_sig(const std::string& algo,
                        RandomNumberGenerator& rng)
    {
    if(str.size() != 8)
-      throw Exception("Invalid input from pk_valid.dat");
+      throw std::runtime_error("Invalid input from pk_valid.dat");
 
 
 #if defined(BOTAN_HAS_NYBERG_RUEPPEL)
@@ -503,7 +503,7 @@ u32bit validate_dh(const std::string& algo,
                    RandomNumberGenerator& rng)
    {
    if(str.size() != 5 && str.size() != 6)
-      throw Exception("Invalid input from pk_valid.dat");
+      throw std::runtime_error("Invalid input from pk_valid.dat");
 
 
 #if defined(BOTAN_HAS_DIFFIE_HELLMAN)
@@ -534,7 +534,7 @@ u32bit validate_dlies(const std::string& algo,
                       RandomNumberGenerator& rng)
    {
    if(str.size() != 6)
-      throw Exception("Invalid input from pk_valid.dat");
+      throw std::runtime_error("Invalid input from pk_valid.dat");
 
 #if defined(BOTAN_HAS_DLIES)
    DL_Group domain(to_bigint(str[0]), to_bigint(str[1]));
@@ -547,7 +547,7 @@ u32bit validate_dlies(const std::string& algo,
    std::vector<std::string> options = split_on(opt_str, '/');
 
    if(options.size() != 3)
-      throw Exception("DLIES needs three options: " + opt_str);
+      throw std::runtime_error("DLIES needs three options: " + opt_str);
 
    MessageAuthenticationCode* mac = get_mac(options[1]);
    u32bit mac_key_len = to_u32bit(options[2]);
diff --git a/doc/examples/pqg_gen.cpp b/doc/examples/pqg_gen.cpp
index 4104e8ecb..e797233f9 100644
--- a/doc/examples/pqg_gen.cpp
+++ b/doc/examples/pqg_gen.cpp
@@ -31,7 +31,7 @@ int main()
 
       std::ifstream in("PQGGen.rsp");
       if(!in)
-         throw Exception("Can't open response file");
+         throw std::runtime_error("Can't open response file");
 
       std::map<std::string, std::string> inputs;
 
@@ -46,7 +46,7 @@ int main()
          std::vector<std::string> name_and_val = split_on(line, '=');
 
          if(name_and_val.size() != 2)
-            throw Decoding_Error("Unexpected input: " + line);
+            throw std::runtime_error("Unexpected input: " + line);
 
          name_and_val[0].erase(name_and_val[0].size()-1);
          name_and_val[1].erase(0, 1);
diff --git a/src/alloc/mem_pool/mem_pool.cpp b/src/alloc/mem_pool/mem_pool.cpp
index 2945a4cef..4180d2602 100644
--- a/src/alloc/mem_pool/mem_pool.cpp
+++ b/src/alloc/mem_pool/mem_pool.cpp
@@ -15,19 +15,6 @@
 
 namespace Botan {
 
-namespace {
-
-/*
-* Memory Allocation Exception
-*/
-struct Memory_Exhaustion : public std::bad_alloc
-   {
-   const char* what() const throw()
-      { return "Ran out of memory, allocation failed"; }
-   };
-
-}
-
 /*
 * Memory_Block Constructor
 */
diff --git a/src/alloc/system_alloc/defalloc.cpp b/src/alloc/system_alloc/defalloc.cpp
index faaeb3c58..311057462 100644
--- a/src/alloc/system_alloc/defalloc.cpp
+++ b/src/alloc/system_alloc/defalloc.cpp
@@ -94,7 +94,7 @@ Allocator* Allocator::get(bool locking)
    if(alloc)
       return alloc;
 
-   throw Exception("Couldn't find an allocator to use in get_allocator");
+   throw Internal_Error("Couldn't find an allocator to use in get_allocator");
    }
 
 }
diff --git a/src/block/lion/lion.cpp b/src/block/lion/lion.cpp
index e590a78ce..d8dfd1fcb 100644
--- a/src/block/lion/lion.cpp
+++ b/src/block/lion/lion.cpp
@@ -116,8 +116,9 @@ Lion::Lion(HashFunction* hash_in, StreamCipher* sc_in, u32bit block_len) :
    {
    if(2*LEFT_SIZE + 1 > BLOCK_SIZE)
       throw Invalid_Argument(name() + ": Chosen block size is too small");
+
    if(!cipher->valid_keylength(LEFT_SIZE))
-      throw Exception(name() + ": This stream/hash combination is invalid");
+      throw Invalid_Argument(name() + ": This stream/hash combo is invalid");
 
    key1.resize(LEFT_SIZE);
    key2.resize(LEFT_SIZE);
diff --git a/src/cert/x509/x509_ext.cpp b/src/cert/x509/x509_ext.cpp
index 9a03c9d23..69b21d8b3 100644
--- a/src/cert/x509/x509_ext.cpp
+++ b/src/cert/x509/x509_ext.cpp
@@ -473,7 +473,7 @@ MemoryVector<byte> Certificate_Policies::encode_inner() const
    {
    // FIXME
 #if 1
-   throw Exception("Certificate_Policies::encode_inner: Bugged");
+   throw Internal_Error("Certificate_Policies::encode_inner: Bugged");
 #else
    std::vector<Policy_Information> policies;
 
diff --git a/src/cms/cms_dalg.cpp b/src/cms/cms_dalg.cpp
index 7ed793f4f..1fc4e2faa 100644
--- a/src/cms/cms_dalg.cpp
+++ b/src/cms/cms_dalg.cpp
@@ -195,7 +195,7 @@ void CMS_Decoder::decode_layer()
       else if(type == OIDS::lookup("CMS.SignedData"))
          {
 #if 1
-         throw Exception("FIXME: not implemented");
+         throw Internal_Error("FIXME: not implemented");
 #else
          u32bit version;
 
@@ -258,11 +258,11 @@ void CMS_Decoder::decode_layer()
          }
       else if(type == OIDS::lookup("CMS.EnvelopedData"))
          {
-         throw Exception("FIXME: not implemented");
+         throw Internal_Error("FIXME: not implemented");
          }
       else if(type == OIDS::lookup("CMS.AuthenticatedData"))
          {
-         throw Exception("FIXME: not implemented");
+         throw Internal_Error("FIXME: not implemented");
          }
       else
          throw Decoding_Error("CMS: Unknown content ID " + type.as_string());
diff --git a/src/cms/cms_ealg.cpp b/src/cms/cms_ealg.cpp
index 2970e8e79..5efa33254 100644
--- a/src/cms/cms_ealg.cpp
+++ b/src/cms/cms_ealg.cpp
@@ -168,7 +168,7 @@ void CMS_Encoder::encrypt_kari(RandomNumberGenerator&,
                                X509_PublicKey*,
                                const std::string&)
    {
-   throw Exception("FIXME: unimplemented");
+   throw Internal_Error("FIXME: unimplemented");
 
 #if 0
    SymmetricKey cek = setup_key(rng, cipher);
@@ -198,7 +198,7 @@ void CMS_Encoder::encrypt(RandomNumberGenerator& rng,
                           const SymmetricKey& kek,
                           const std::string& user_cipher)
    {
-   throw Exception("FIXME: untested");
+   throw Internal_Error("FIXME: untested");
 
    const std::string cipher = choose_algo(user_cipher, "TripleDES");
    SymmetricKey cek = setup_key(rng, cipher);
@@ -232,7 +232,7 @@ void CMS_Encoder::encrypt(RandomNumberGenerator&,
                           const std::string& user_cipher)
    {
    const std::string cipher = choose_algo(user_cipher, "TripleDES");
-   throw Exception("FIXME: unimplemented");
+   throw Internal_Error("FIXME: unimplemented");
    /*
    SymmetricKey cek = setup_key(key);
 
@@ -375,7 +375,7 @@ void CMS_Encoder::authenticate(const X509_Certificate&,
                                const std::string& mac_algo)
    {
    const std::string mac = choose_algo(mac_algo, "HMAC(SHA-1)");
-   throw Exception("FIXME: unimplemented");
+   throw Internal_Error("FIXME: unimplemented");
    }
 
 /*
@@ -385,7 +385,7 @@ void CMS_Encoder::authenticate(const SymmetricKey&,
                                const std::string& mac_algo)
    {
    const std::string mac = choose_algo(mac_algo, "HMAC(SHA-1)");
-   throw Exception("FIXME: unimplemented");
+   throw Internal_Error("FIXME: unimplemented");
    }
 
 /*
@@ -395,7 +395,7 @@ void CMS_Encoder::authenticate(const std::string&,
                                const std::string& mac_algo)
    {
    const std::string mac = choose_algo(mac_algo, "HMAC(SHA-1)");
-   throw Exception("FIXME: unimplemented");
+   throw Internal_Error("FIXME: unimplemented");
    }
 
 }
diff --git a/src/constructs/cryptobox/cryptobox.cpp b/src/constructs/cryptobox/cryptobox.cpp
index ba7553c55..20435fa59 100644
--- a/src/constructs/cryptobox/cryptobox.cpp
+++ b/src/constructs/cryptobox/cryptobox.cpp
@@ -135,7 +135,7 @@ std::string decrypt(const byte input[], u32bit input_len,
 
    if(!same_mem(computed_mac, ciphertext + VERSION_CODE_LEN + PBKDF_SALT_LEN,
                 MAC_OUTPUT_LEN))
-      throw Integrity_Failure("CryptoBox integrity failure");
+      throw Decoding_Error("CryptoBox integrity failure");
 
    return pipe.read_all_as_string(0);
    }
diff --git a/src/filters/bzip2/bzip2.cpp b/src/filters/bzip2/bzip2.cpp
index 4cdca5355..9dcee8fdf 100644
--- a/src/filters/bzip2/bzip2.cpp
+++ b/src/filters/bzip2/bzip2.cpp
@@ -96,7 +96,7 @@ void Bzip_Compression::start_msg()
    clear();
    bz = new Bzip_Stream;
    if(BZ2_bzCompressInit(&(bz->stream), level, 0, 0) != BZ_OK)
-      throw Exception("Bzip_Compression: Memory allocation error");
+      throw Memory_Exhaustion();
    }
 
 /*
@@ -196,13 +196,15 @@ void Bzip_Decompression::write(const byte input_arr[], u32bit length)
       if(rc != BZ_OK && rc != BZ_STREAM_END)
          {
          clear();
+
          if(rc == BZ_DATA_ERROR)
             throw Decoding_Error("Bzip_Decompression: Data integrity error");
-         if(rc == BZ_DATA_ERROR_MAGIC)
+         else if(rc == BZ_DATA_ERROR_MAGIC)
             throw Decoding_Error("Bzip_Decompression: Invalid input");
-         if(rc == BZ_MEM_ERROR)
-            throw Exception("Bzip_Decompression: Memory allocation error");
-         throw Exception("Bzip_Decompression: Unknown decompress error");
+         else if(rc == BZ_MEM_ERROR)
+            throw Memory_Exhaustion();
+         else
+            throw std::runtime_error("Bzip2 decompression: Unknown error");
          }
 
       send(buffer, buffer.size() - bz->stream.avail_out);
@@ -228,7 +230,7 @@ void Bzip_Decompression::start_msg()
    bz = new Bzip_Stream;
 
    if(BZ2_bzDecompressInit(&(bz->stream), 0, small_mem) != BZ_OK)
-      throw Exception("Bzip_Decompression: Memory allocation error");
+      throw Memory_Exhaustion();
 
    no_writes = true;
    }
@@ -252,7 +254,7 @@ void Bzip_Decompression::end_msg()
       if(rc != BZ_OK && rc != BZ_STREAM_END)
          {
          clear();
-         throw Exception("Bzip_Decompression: Error finalizing decompression");
+         throw Decoding_Error("Bzip_Decompression: Error finalizing");
          }
 
       send(buffer, buffer.size() - bz->stream.avail_out);
diff --git a/src/filters/modes/cbc/cbc.cpp b/src/filters/modes/cbc/cbc.cpp
index 059b239e8..7722fad2f 100644
--- a/src/filters/modes/cbc/cbc.cpp
+++ b/src/filters/modes/cbc/cbc.cpp
@@ -79,7 +79,7 @@ void CBC_Encryption::buffered_final(const byte input[], u32bit length)
    if(length % cipher->BLOCK_SIZE == 0)
       buffered_block(input, length);
    else if(length != 0)
-      throw Exception(name() + ": Did not pad to full blocksize");
+      throw Encoding_Error(name() + ": Did not pad to full blocksize");
    }
 
 void CBC_Encryption::write(const byte input[], u32bit input_length)
diff --git a/src/filters/modes/cts/cts.cpp b/src/filters/modes/cts/cts.cpp
index 3a15a1d68..b27b9b3c5 100644
--- a/src/filters/modes/cts/cts.cpp
+++ b/src/filters/modes/cts/cts.cpp
@@ -101,7 +101,8 @@ void CTS_Encryption::write(const byte input[], u32bit length)
 void CTS_Encryption::end_msg()
    {
    if(position < cipher->BLOCK_SIZE + 1)
-      throw Exception("CTS_Encryption: insufficient data to encrypt");
+      throw Encoding_Error(name() + ": insufficient data to encrypt");
+
    xor_buf(state, buffer, cipher->BLOCK_SIZE);
    cipher->encrypt(state);
    SecureVector<byte> cn = state;
diff --git a/src/filters/modes/eax/eax_dec.cpp b/src/filters/modes/eax/eax_dec.cpp
index f41327ffc..998773697 100644
--- a/src/filters/modes/eax/eax_dec.cpp
+++ b/src/filters/modes/eax/eax_dec.cpp
@@ -98,13 +98,13 @@ void EAX_Decryption::do_write(const byte input[], u32bit length)
 void EAX_Decryption::end_msg()
    {
    if((queue_end - queue_start) != TAG_SIZE)
-      throw Integrity_Failure(name() + ": Message authentication failure");
+      throw Decoding_Error(name() + ": Message authentication failure");
 
    SecureVector<byte> data_mac = cmac->final();
 
    for(u32bit j = 0; j != TAG_SIZE; ++j)
       if(queue[queue_start+j] != (data_mac[j] ^ nonce_mac[j] ^ header_mac[j]))
-         throw Integrity_Failure(name() + ": Message authentication failure");
+         throw Decoding_Error(name() + ": Message authentication failure");
 
    queue_start = queue_end = 0;
    }
diff --git a/src/filters/modes/ecb/ecb.cpp b/src/filters/modes/ecb/ecb.cpp
index c13d0fd37..2ce6576e3 100644
--- a/src/filters/modes/ecb/ecb.cpp
+++ b/src/filters/modes/ecb/ecb.cpp
@@ -103,7 +103,7 @@ void ECB_Encryption::buffered_final(const byte input[], u32bit input_length)
    if(input_length % cipher->BLOCK_SIZE == 0)
       buffered_block(input, input_length);
    else if(input_length != 0)
-      throw Exception(name() + ": Did not pad to full blocksize");
+      throw Encoding_Error(name() + ": Did not pad to full blocksize");
    }
 
 /*
diff --git a/src/filters/modes/xts/xts.cpp b/src/filters/modes/xts/xts.cpp
index afeea24b5..cfea0b34b 100644
--- a/src/filters/modes/xts/xts.cpp
+++ b/src/filters/modes/xts/xts.cpp
@@ -168,7 +168,7 @@ void XTS_Encryption::buffered_block(const byte input[], u32bit length)
 void XTS_Encryption::buffered_final(const byte input[], u32bit length)
    {
    if(length <= cipher->BLOCK_SIZE)
-      throw Exception("XTS_Encryption: insufficient data to encrypt");
+      throw Encoding_Error("XTS_Encryption: insufficient data to encrypt");
 
    if(length % cipher->BLOCK_SIZE == 0)
       {
@@ -323,7 +323,7 @@ void XTS_Decryption::buffered_block(const byte input[], u32bit input_length)
 void XTS_Decryption::buffered_final(const byte input[], u32bit input_length)
    {
    if(input_length <= cipher->BLOCK_SIZE)
-      throw Exception("XTS_Decryption: insufficient data to decrypt");
+      throw Decoding_Error("XTS_Decryption: insufficient data to decrypt");
 
    if(input_length % cipher->BLOCK_SIZE == 0)
       {
diff --git a/src/filters/pipe_rw.cpp b/src/filters/pipe_rw.cpp
index 756a1cf09..de77c6b43 100644
--- a/src/filters/pipe_rw.cpp
+++ b/src/filters/pipe_rw.cpp
@@ -34,7 +34,7 @@ Pipe::message_id Pipe::get_message_no(const std::string& func_name,
 void Pipe::write(const byte input[], u32bit length)
    {
    if(!inside_msg)
-      throw Exception("Cannot write to a Pipe while it is not processing");
+      throw Invalid_State("Cannot write to a Pipe while it is not processing");
    pipe->write(input, length);
    }
 
diff --git a/src/filters/pk_filts/pk_filts.cpp b/src/filters/pk_filts/pk_filts.cpp
index d604436e0..05b45227f 100644
--- a/src/filters/pk_filts/pk_filts.cpp
+++ b/src/filters/pk_filts/pk_filts.cpp
@@ -73,7 +73,7 @@ void PK_Verifier_Filter::write(const byte input[], u32bit length)
 void PK_Verifier_Filter::end_msg()
    {
    if(signature.empty())
-      throw Exception("PK_Verifier_Filter: No signature to check against");
+      throw Invalid_State("PK_Verifier_Filter: No signature to check against");
    bool is_valid = verifier->check_signature(signature, signature.size());
    send((is_valid ? 1 : 0));
    }
diff --git a/src/filters/zlib/zlib.cpp b/src/filters/zlib/zlib.cpp
index 246e32924..171caa73f 100644
--- a/src/filters/zlib/zlib.cpp
+++ b/src/filters/zlib/zlib.cpp
@@ -95,7 +95,7 @@ void Zlib_Compression::start_msg()
    clear();
    zlib = new Zlib_Stream;
    if(deflateInit(&(zlib->stream), level) != Z_OK)
-      throw Exception("Zlib_Compression: Memory allocation error");
+      throw Memory_Exhaustion();
    }
 
 /*
@@ -187,7 +187,7 @@ void Zlib_Decompression::start_msg()
    clear();
    zlib = new Zlib_Stream;
    if(inflateInit(&(zlib->stream)) != Z_OK)
-      throw Exception("Zlib_Decompression: Memory allocation error");
+      throw Memory_Exhaustion();
    }
 
 /*
@@ -215,11 +215,12 @@ void Zlib_Decompression::write(const byte input_arr[], u32bit length)
          clear();
          if(rc == Z_DATA_ERROR)
             throw Decoding_Error("Zlib_Decompression: Data integrity error");
-         if(rc == Z_NEED_DICT)
+         else if(rc == Z_NEED_DICT)
             throw Decoding_Error("Zlib_Decompression: Need preset dictionary");
-         if(rc == Z_MEM_ERROR)
-            throw Exception("Zlib_Decompression: Memory allocation error");
-         throw Exception("Zlib_Decompression: Unknown decompress error");
+         else if(rc == Z_MEM_ERROR)
+            throw Memory_Exhaustion();
+         else
+            throw std::runtime_error("Zlib decompression: Unknown error");
          }
 
       send(buffer.begin(), buffer.size() - zlib->stream.avail_out);
@@ -258,7 +259,7 @@ void Zlib_Decompression::end_msg()
       if(rc != Z_OK && rc != Z_STREAM_END)
          {
          clear();
-         throw Exception("Zlib_Decompression: Error finalizing decompression");
+         throw Decoding_Error("Zlib_Decompression: Error finalizing");
          }
 
       send(buffer.begin(), buffer.size() - zlib->stream.avail_out);
diff --git a/src/math/gfpmath/point_gfp.cpp b/src/math/gfpmath/point_gfp.cpp
index f95add9f7..4203a3db3 100644
--- a/src/math/gfpmath/point_gfp.cpp
+++ b/src/math/gfpmath/point_gfp.cpp
@@ -921,7 +921,7 @@ SecureVector<byte> EC2OSP(const PointGFp& point, byte format)
       }
    else
       {
-      throw Format_Error("illegal point encoding format specification");
+      throw Invalid_Argument("illegal point encoding format specification");
       }
    return result;
    }
@@ -1078,7 +1078,7 @@ PointGFp OS2ECP(MemoryRegion<byte> const& os, const CurveGFp& curve)
             }
          break;
       default:
-         throw Format_Error("encountered illegal format specification while decoding point");
+         throw Invalid_Argument("encountered illegal format specification while decoding point");
       }
    z = GFpElement(curve.get_p(), BigInt(1));
    //assert((x.is_trf_to_mres() && x.is_use_montgm()) || !x.is_trf_to_mres());
diff --git a/src/math/numbertheory/powm_mnt.cpp b/src/math/numbertheory/powm_mnt.cpp
index e356387c0..2d18ccdef 100644
--- a/src/math/numbertheory/powm_mnt.cpp
+++ b/src/math/numbertheory/powm_mnt.cpp
@@ -156,10 +156,9 @@ BigInt Montgomery_Exponentiator::execute() const
 Montgomery_Exponentiator::Montgomery_Exponentiator(const BigInt& mod,
    Power_Mod::Usage_Hints hints)
    {
-   if(!mod.is_positive())
-      throw Exception("Montgomery_Exponentiator: modulus must be positive");
-   if(mod.is_even())
-      throw Exception("Montgomery_Exponentiator: modulus must be odd");
+   // Montgomery reduction only works for positive odd moduli
+   if(!mod.is_positive() || mod.is_even())
+      throw Invalid_Argument("Montgomery_Exponentiator: invalid modulus");
 
    window_bits = 0;
    this->hints = hints;
diff --git a/src/mutex/pthreads/mux_pthr.cpp b/src/mutex/pthreads/mux_pthr.cpp
index 75a116fe8..165132239 100644
--- a/src/mutex/pthreads/mux_pthr.cpp
+++ b/src/mutex/pthreads/mux_pthr.cpp
@@ -28,19 +28,19 @@ Mutex* Pthread_Mutex_Factory::make()
          void lock()
             {
             if(pthread_mutex_lock(&mutex) != 0)
-               throw Exception("Pthread_Mutex::lock: Error occured");
+               throw Invalid_State("Pthread_Mutex::lock: Error occured");
             }
 
          void unlock()
             {
             if(pthread_mutex_unlock(&mutex) != 0)
-               throw Exception("Pthread_Mutex::unlock: Error occured");
+               throw Invalid_State("Pthread_Mutex::unlock: Error occured");
             }
 
          Pthread_Mutex()
             {
             if(pthread_mutex_init(&mutex, 0) != 0)
-               throw Exception("Pthread_Mutex: initialization failed");
+               throw Invalid_State("Pthread_Mutex: initialization failed");
             }
 
          ~Pthread_Mutex()
diff --git a/src/pk_pad/eme1/eme1.cpp b/src/pk_pad/eme1/eme1.cpp
index 13f68f8e4..d99ffaf58 100644
--- a/src/pk_pad/eme1/eme1.cpp
+++ b/src/pk_pad/eme1/eme1.cpp
@@ -21,7 +21,7 @@ SecureVector<byte> EME1::pad(const byte in[], u32bit in_length,
    key_length /= 8;
 
    if(in_length > key_length - 2*HASH_LENGTH - 1)
-      throw Exception("EME1: Input is too large");
+      throw Invalid_Argument("EME1: Input is too large");
 
    SecureVector<byte> out(key_length);
 
diff --git a/src/pubkey/dl_group/dl_group.cpp b/src/pubkey/dl_group/dl_group.cpp
index a2e239783..7940e69b2 100644
--- a/src/pubkey/dl_group/dl_group.cpp
+++ b/src/pubkey/dl_group/dl_group.cpp
@@ -193,7 +193,7 @@ const BigInt& DL_Group::get_q() const
    {
    init_check();
    if(q == 0)
-      throw Format_Error("DLP group has no q prime specified");
+      throw Invalid_State("DLP group has no q prime specified");
    return q;
    }
 
@@ -325,7 +325,7 @@ BigInt DL_Group::make_dsa_generator(const BigInt& p, const BigInt& q)
       }
 
    if(g == 1)
-      throw Exception("DL_Group: Couldn't create a suitable generator");
+      throw Internal_Error("DL_Group: Couldn't create a suitable generator");
 
    return g;
    }
diff --git a/src/pubkey/dlies/dlies.cpp b/src/pubkey/dlies/dlies.cpp
index 3a3ab52ee..6ef3292e1 100644
--- a/src/pubkey/dlies/dlies.cpp
+++ b/src/pubkey/dlies/dlies.cpp
@@ -127,7 +127,7 @@ SecureVector<byte> DLIES_Decryptor::dec(const byte msg[], u32bit length) const
       mac->update(0);
    SecureVector<byte> T2 = mac->final();
    if(T != T2)
-      throw Integrity_Failure("DLIES: message authentication failed");
+      throw Decoding_Error("DLIES: message authentication failed");
 
    xor_buf(C, K.begin() + mac_keylen, C.size());
 
diff --git a/src/pubkey/dsa/dsa.cpp b/src/pubkey/dsa/dsa.cpp
index b0688ae0d..5be3e1d48 100644
--- a/src/pubkey/dsa/dsa.cpp
+++ b/src/pubkey/dsa/dsa.cpp
@@ -97,6 +97,8 @@ SecureVector<byte> DSA_PrivateKey::sign(const byte in[], u32bit length,
    {
    const BigInt& q = group_q();
 
+   rng.add_entropy(in, length);
+
    BigInt k;
    do
       k.randomize(rng, q.bits());
diff --git a/src/pubkey/pubkey.cpp b/src/pubkey/pubkey.cpp
index 44e31159c..9b5c9180b 100644
--- a/src/pubkey/pubkey.cpp
+++ b/src/pubkey/pubkey.cpp
@@ -73,7 +73,7 @@ PK_Encryptor_MR_with_EME::enc(const byte msg[],
       message.set(msg, length);
 
    if(8*(message.size() - 1) + high_bit(message[0]) > key.max_input_bits())
-      throw Exception("PK_Encryptor_MR_with_EME: Input is too large");
+      throw Invalid_Argument("PK_Encryptor_MR_with_EME: Input is too large");
 
    return key.encrypt(message, message.size(), rng);
    }
@@ -113,11 +113,11 @@ SecureVector<byte> PK_Decryptor_MR_with_EME::dec(const byte msg[],
       }
    catch(Invalid_Argument)
       {
-      throw Exception("PK_Decryptor_MR_with_EME: Input is invalid");
+      throw Decoding_Error("PK_Decryptor_MR_with_EME: Input is invalid");
       }
    catch(Decoding_Error)
       {
-      throw Exception("PK_Decryptor_MR_with_EME: Input is invalid");
+      throw Decoding_Error("PK_Decryptor_MR_with_EME: Input is invalid");
       }
    }
 
diff --git a/src/s2k/pbkdf1/pbkdf1.cpp b/src/s2k/pbkdf1/pbkdf1.cpp
index 04e3aa453..fcc5b9a97 100644
--- a/src/s2k/pbkdf1/pbkdf1.cpp
+++ b/src/s2k/pbkdf1/pbkdf1.cpp
@@ -18,10 +18,10 @@ OctetString PKCS5_PBKDF1::derive(u32bit key_len,
                                  u32bit iterations) const
    {
    if(iterations == 0)
-      throw Invalid_Argument("PKCS#5 PBKDF1: Invalid iteration count");
+      throw Invalid_Argument("PKCS5_PBKDF1: Invalid iteration count");
 
    if(key_len > hash->OUTPUT_LENGTH)
-      throw Exception("PKCS#5 PBKDF1: Requested output length too long");
+      throw Invalid_Argument("PKCS5_PBKDF1: Requested output length too long");
 
    hash->update(passphrase);
    hash->update(salt, salt_size);
diff --git a/src/stream/stream_cipher.h b/src/stream/stream_cipher.h
index 29c16c8b5..cb6fb3481 100644
--- a/src/stream/stream_cipher.h
+++ b/src/stream/stream_cipher.h
@@ -42,8 +42,8 @@ class BOTAN_DLL StreamCipher : public SymmetricAlgorithm
       virtual void set_iv(const byte[], u32bit iv_len)
          {
          if(iv_len)
-            throw Exception("The stream cipher " + name() +
-                            " does not support resyncronization");
+            throw Invalid_Argument("The stream cipher " + name() +
+                                   " does not support resyncronization");
          }
 
       /**
diff --git a/src/utils/exceptn.h b/src/utils/exceptn.h
index d106de1c0..86efebc7c 100644
--- a/src/utils/exceptn.h
+++ b/src/utils/exceptn.h
@@ -1,6 +1,6 @@
 /*
 * Exceptions
-* (C) 1999-2007 Jack Lloyd
+* (C) 1999-2009 Jack Lloyd
 *
 * Distributed under the terms of the Botan license
 */
@@ -16,32 +16,8 @@
 
 namespace Botan {
 
-/*
-* Exception Base Class
-*/
-class BOTAN_DLL Exception : public std::exception
-   {
-   public:
-      Exception(const std::string& m = "Unknown error") :
-         msg("Botan: " + m)
-         {}
-
-      const char* what() const throw() { return msg.c_str(); }
-
-      virtual ~Exception() throw() {}
-   private:
-      std::string msg;
-   };
-
-/*
-* Invalid_Argument Exception
-*/
-struct BOTAN_DLL Invalid_Argument : public Exception
-   {
-   Invalid_Argument(const std::string& err = "") :
-      Exception(err)
-      {}
-   };
+typedef std::runtime_error Exception;
+typedef std::invalid_argument Invalid_Argument;
 
 /*
 * Invalid_State Exception
@@ -54,16 +30,6 @@ struct BOTAN_DLL Invalid_State : public Exception
    };
 
 /*
-* Format_Error Exception
-*/
-struct BOTAN_DLL Format_Error : public Exception
-   {
-   Format_Error(const std::string& err = "") :
-      Exception(err)
-      {}
-   };
-
-/*
 * Lookup_Error Exception
 */
 struct BOTAN_DLL Lookup_Error : public Exception
@@ -150,29 +116,29 @@ struct BOTAN_DLL Algorithm_Not_Found : public Lookup_Error
 /*
 * Invalid_Algorithm_Name Exception
 */
-struct BOTAN_DLL Invalid_Algorithm_Name : public Format_Error
+struct BOTAN_DLL Invalid_Algorithm_Name : public Invalid_Argument
    {
    Invalid_Algorithm_Name(const std::string& name):
-      Format_Error("Invalid algorithm name: " + name)
+      Invalid_Argument("Invalid algorithm name: " + name)
       {}
    };
 
 /*
 * Encoding_Error Exception
 */
-struct BOTAN_DLL Encoding_Error : public Format_Error
+struct BOTAN_DLL Encoding_Error : public Invalid_Argument
    {
    Encoding_Error(const std::string& name) :
-      Format_Error("Encoding error: " + name) {}
+      Invalid_Argument("Encoding error: " + name) {}
    };
 
 /*
 * Decoding_Error Exception
 */
-struct BOTAN_DLL Decoding_Error : public Format_Error
+struct BOTAN_DLL Decoding_Error : public Invalid_Argument
    {
    Decoding_Error(const std::string& name) :
-      Format_Error("Decoding error: " + name) {}
+      Invalid_Argument("Decoding error: " + name) {}
    };
 
 /*
@@ -195,37 +161,22 @@ struct BOTAN_DLL Stream_IO_Error : public Exception
    };
 
 /*
-* Configuration Error Exception
-*/
-struct BOTAN_DLL Config_Error : public Format_Error
-   {
-   Config_Error(const std::string& err) :
-      Format_Error("Config error: " + err)
-      {}
-
-   Config_Error(const std::string& err, u32bit line) :
-      Format_Error("Config error at line " + to_string(line) + ": " + err)
-      {}
-   };
-
-/*
-* Integrity Failure Exception
+* Self Test Failure Exception
 */
-struct BOTAN_DLL Integrity_Failure : public Internal_Error
+struct BOTAN_DLL Self_Test_Failure : public Internal_Error
    {
-   Integrity_Failure(const std::string& err) :
-      Internal_Error("Integrity failure: " + err)
+   Self_Test_Failure(const std::string& err) :
+      Internal_Error("Self test failed: " + err)
       {}
    };
 
 /*
-* Self Test Failure Exception
+* Memory Allocation Exception
 */
-struct BOTAN_DLL Self_Test_Failure : public Internal_Error
+struct BOTAN_DLL Memory_Exhaustion : public std::bad_alloc
    {
-   Self_Test_Failure(const std::string& err) :
-      Internal_Error("Self test failed: " + err)
-      {}
+   const char* what() const throw()
+      { return "Ran out of memory, allocation failed"; }
    };
 
 }
diff --git a/src/utils/parsing.cpp b/src/utils/parsing.cpp
index 58a8e0b38..4b99ac1ec 100644
--- a/src/utils/parsing.cpp
+++ b/src/utils/parsing.cpp
@@ -168,7 +168,7 @@ std::vector<std::string> split_on(const std::string& str, char delim)
       }
 
    if(substr == "")
-      throw Format_Error("Unable to split string: " + str);
+      throw Invalid_Argument("Unable to split string: " + str);
    elems.push_back(substr);
 
    return elems;