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-rw-r--r--cypher.cpp96
1 files changed, 37 insertions, 59 deletions
diff --git a/cypher.cpp b/cypher.cpp
index ea511ef..7bf0c3e 100644
--- a/cypher.cpp
+++ b/cypher.cpp
@@ -32,14 +32,14 @@
#include <iostream>
#include <string>
#include <cstdio>
+#include <gcrypt.h>
#include "cypher.h"
#include "keyDerivation.h"
+#include "mpi.h"
+#include "log.h"
-extern "C" {
-#include <gcrypt.h>
-}
void Cypher::cypher(Buffer& buf, seq_nr_t seq_nr, sender_id_t sender_id)
{
@@ -78,37 +78,32 @@ AesIcmCypher::AesIcmCypher() : salt_(Buffer(14))
if( !gcry_control(GCRYCTL_ANY_INITIALIZATION_P) )
{
if( !gcry_check_version( MIN_GCRYPT_VERSION ) ) {
- std::cerr << "Invalid Version of libgcrypt, should be >= ";
- std::cerr << MIN_GCRYPT_VERSION << std::endl;
+ cLog.msg(Log::PRIO_ERR) << "Invalid Version of libgcrypt, should be >= " << MIN_GCRYPT_VERSION;
return;
}
- // do NOT allocate a pool of secure memory!
- // this is NOT thread safe!
-
-// /* Allocate a pool of secure memory. This also drops priviliges
-// on some systems. */
-// err = gcry_control(GCRYCTL_INIT_SECMEM, GCRYPT_SEC_MEM, 0);
-// if( err ) {
-// std::cerr << "Failed to allocate " << GCRYPT_SEC_MEM << "bytes of secure memory: ";
-// std::cerr << gpg_strerror( err ) << std::endl;
-// return;
-// }
+ // do NOT allocate a pool of secure memory!
+ // this is NOT thread safe!
+ // /* Allocate a pool of secure memory. This also drops priviliges
+ // on some systems. */
+ // err = gcry_control(GCRYCTL_INIT_SECMEM, GCRYPT_SEC_MEM, 0);
+ // if( err ) {
+ // std::cerr << "Failed to allocate " << GCRYPT_SEC_MEM << "bytes of secure memory: ";
+ // std::cerr << gpg_strerror( err ) << std::endl;
+ // return;
+ // }
/* Tell Libgcrypt that initialization has completed. */
err = gcry_control(GCRYCTL_INITIALIZATION_FINISHED);
if( err ) {
- std::cerr << "Failed to finish the initialization of libgcrypt";
- std::cerr << gpg_strerror( err ) << std::endl;
+ cLog.msg(Log::PRIO_CRIT) << "AesIcmCypher::AesIcmCypher: Failed to finish the initialization of libgcrypt: " << gpg_strerror( err );
return;
-// } else {
-// std::cout << "AesIcmCypher::AesIcmCypher: libgcrypt init finished" << std::endl;
+ } else {
+ cLog.msg(Log::PRIO_NOTICE) << "AesIcmCypher::AesIcmCypher: libgcrypt init finished";
}
}
gcry_cipher_open( &cipher_, GCRY_CIPHER_AES128, GCRY_CIPHER_MODE_CTR, 0 );
-
-// std::cout << "Keysize: " << gcry_cipher_get_algo_keylen( GCRY_CIPHER_AES128 ) << std::endl;
}
@@ -121,16 +116,14 @@ AesIcmCypher::~AesIcmCypher()
void AesIcmCypher::setKey(Buffer key)
{
gcry_error_t err;
+ // FIXXME: hardcoded keysize
err = gcry_cipher_setkey( cipher_, key.getBuf(), 16 );
if( err )
- std::cerr << "Failed to set cipher key: " << gpg_strerror( err ) << std::endl;
+ cLog.msg(Log::PRIO_ERR) << "AesIcmCypher::setKey: Failed to set cipher key: " << gpg_strerror( err );
}
void AesIcmCypher::setSalt(Buffer salt)
{
-// std::cout << "AesIcmCypher::setSalt" << std::endl;
-// salt.printHexDump();
-// std::cout << std::endl;
salt_ = salt;
}
@@ -140,50 +133,35 @@ Buffer AesIcmCypher::getBitStream(u_int32_t length, seq_nr_t seq_nr, sender_id_t
Buffer buf(length);
-// // set IV
-// // where the 128-bit integer value IV SHALL be defined by the SSRC, the
-// // SRTP packet index i, and the SRTP session salting key k_s, as below.
-// //
-// // IV = (k_s * 2^16) XOR (SSRC * 2^64) XOR (i * 2^16)
-// // sizeof(k_s) = 112 bit, random
-
-
- u_int8_t iv[16];
- std::memset(iv, 0, 16); //initalize iv
-
- // apply salt:
- std::memcpy(&iv[2], salt_.getBuf(), 14);
+ // // set IV
+ // // where the 128-bit integer value IV SHALL be defined by the SSRC, the
+ // // SRTP packet index i, and the SRTP session salting key k_s, as below.
+ // //
+ // // IV = (k_s * 2^16) XOR (SSRC * 2^64) XOR (i * 2^16)
+ // // sizeof(k_s) = 112 bit, random
-// std::cout << "salt:" << std::endl;
-// salt_.printHexDump();
-// std::cout << std::endl;
+ Mpi iv(128);
+ Mpi salt = Mpi(salt_.getBuf(), salt_.getLength());
+ Mpi sid = sender_id;
+ Mpi seq = seq_nr;
- // apply sender id:
- for(u_int8_t index = 0; index < sizeof(sender_id); index++)
- iv[index+8] = iv[index+8] ^ ((sender_id>>index) & 0xFF);
+ iv = salt.mul2exp(16) ^ sid.mul2exp(64) ^ seq.mul2exp(16);
- // apply seq nr:
- for(u_int8_t index = 0; index < sizeof(seq_nr); index++)
- iv[index+2] = iv[index+2] ^ ((seq_nr>>index) & 0xFF);
-
- err = gcry_cipher_setiv( cipher_, iv, 16 );
- if( err )
- {
- std::cerr << "Failed to set cipher IV: " << gpg_strerror( err ) << std::endl;
+ err = gcry_cipher_setiv( cipher_, iv.getBuf().getBuf(), 16 );
+ if( err ) {
+ cLog.msg(Log::PRIO_ERR) << "AesIcmCypher: Failed to set cipher IV: " << gpg_strerror( err );
return Buffer(0);
}
err = gcry_cipher_reset( cipher_ );
- if( err )
- {
- std::cerr << "Failed to reset cipher: " << gpg_strerror( err ) << std::endl;
+ if( err ) {
+ cLog.msg(Log::PRIO_ERR) << "AesIcmCypher: Failed to reset cipher: " << gpg_strerror( err );
return Buffer(0);
}
err = gcry_cipher_encrypt( cipher_, buf, buf.getLength(), 0, 0 );
- if( err )
- {
- std::cerr << "Failed to generate cipher bitstream: " << gpg_strerror( err ) << std::endl;
+ if( err ) {
+ cLog.msg(Log::PRIO_ERR) << "AesIcmCypher: Failed to generate cipher bitstream: " << gpg_strerror( err );
return Buffer(0);
}