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Keep aligned buffers around, instead of allocing on each packet

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Fixes #238 github issue.
Also fixes armel "Bad alignment" problem.
This commit is contained in:
Keith Winstein
2012-04-24 17:22:54 -04:00
parent 3ccfe64bfb
commit 22e7cf60d3
4 changed files with 43 additions and 30 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/crypto/crypto.cc
+29 -24
View File
@@ -139,7 +139,10 @@ string Base64Key::printable_key( void ) const
Session::Session( Base64Key s_key )
: key( s_key ), ctx_buf( ae_ctx_sizeof() ),
ctx( (ae_ctx *)ctx_buf.data() ), blocks_encrypted( 0 )
ctx( (ae_ctx *)ctx_buf.data() ), blocks_encrypted( 0 ),
plaintext_buffer( RECEIVE_MTU ),
ciphertext_buffer( RECEIVE_MTU ),
nonce_buffer( Nonce::NONCE_LEN )
{
if ( AE_SUCCESS != ae_init( ctx, key.data(), 16, 12, 16 ) ) {
throw CryptoException( "Could not initialize AES-OCB context." );
@@ -194,20 +197,19 @@ string Session::encrypt( Message plaintext )
const size_t pt_len = plaintext.text.size();
const int ciphertext_len = pt_len + 16;
AlignedBuffer ciphertext( ciphertext_len );
AlignedBuffer pt( pt_len, plaintext.text.data() );
assert( (size_t)ciphertext_len <= ciphertext_buffer.len() );
assert( pt_len <= plaintext_buffer.len() );
if ( (uint64_t( plaintext.nonce.data() ) & 0xf) != 0 ) {
throw CryptoException( "Bad alignment." );
}
memcpy( plaintext_buffer.data(), plaintext.text.data(), pt_len );
memcpy( nonce_buffer.data(), plaintext.nonce.data(), Nonce::NONCE_LEN );
if ( ciphertext_len != ae_encrypt( ctx, /* ctx */
plaintext.nonce.data(), /* nonce */
pt.data(), /* pt */
pt.len(), /* pt_len */
nonce_buffer.data(), /* nonce */
plaintext_buffer.data(), /* pt */
pt_len, /* pt_len */
NULL, /* ad */
0, /* ad_len */
ciphertext.data(), /* ct */
ciphertext_buffer.data(), /* ct */
NULL, /* tag */
AE_FINALIZE ) ) { /* final */
throw CryptoException( "ae_encrypt() returned error." );
@@ -235,7 +237,7 @@ string Session::encrypt( Message plaintext )
throw CryptoException( "Encrypted 2^47 blocks.", true );
}
string text( ciphertext.data(), ciphertext.len() );
string text( ciphertext_buffer.data(), ciphertext_len );
return plaintext.nonce.cc_str() + text;
}
@@ -256,23 +258,26 @@ Message Session::decrypt( string ciphertext )
exit( 1 );
}
Nonce __attribute__((__aligned__ (16))) nonce( str, 8 );
AlignedBuffer body( body_len, str + 8 );
AlignedBuffer plaintext( pt_len );
assert( (size_t)body_len <= ciphertext_buffer.len() );
assert( (size_t)pt_len <= plaintext_buffer.len() );
if ( pt_len != ae_decrypt( ctx, /* ctx */
nonce.data(), /* nonce */
body.data(), /* ct */
body.len(), /* ct_len */
NULL, /* ad */
0, /* ad_len */
plaintext.data(), /* pt */
NULL, /* tag */
AE_FINALIZE ) ) { /* final */
Nonce nonce( str, 8 );
memcpy( ciphertext_buffer.data(), str + 8, body_len );
memcpy( nonce_buffer.data(), nonce.data(), Nonce::NONCE_LEN );
if ( pt_len != ae_decrypt( ctx, /* ctx */
nonce_buffer.data(), /* nonce */
ciphertext_buffer.data(), /* ct */
body_len, /* ct_len */
NULL, /* ad */
0, /* ad_len */
plaintext_buffer.data(), /* pt */
NULL, /* tag */
AE_FINALIZE ) ) { /* final */
throw CryptoException( "Packet failed integrity check." );
}
Message ret( nonce, string( plaintext.data(), plaintext.len() ) );
Message ret( nonce, string( plaintext_buffer.data(), pt_len ) );
return ret;
}