diff options
Diffstat (limited to 'cipher.cpp')
| -rw-r--r-- | cipher.cpp | 72 |
1 files changed, 41 insertions, 31 deletions
@@ -39,28 +39,34 @@ #include "log.h" -void Cipher::encrypt(const PlainPacket & in,EncryptedPacket & out, seq_nr_t seq_nr, sender_id_t sender_id) +void Cipher::encrypt(const PlainPacket & in, EncryptedPacket & out, seq_nr_t seq_nr, sender_id_t sender_id) { - cipher(out.payload_, in.complete_payload_ , in.complete_payload_length_, seq_nr, sender_id); + u_int32_t len = cipher(out.payload_, out.payload_length_, in.complete_payload_ , in.complete_payload_length_, seq_nr, sender_id); out.setSenderId(sender_id); out.setSeqNr(seq_nr); - out.setPayloadLength(in.complete_payload_length_); + out.setPayloadLength(len); } -void Cipher::decrypt(const EncryptedPacket & in,PlainPacket & out) +void Cipher::decrypt(const EncryptedPacket & in, PlainPacket & out) { - cipher(out.complete_payload_, in.payload_ , in.payload_length_, in.getSeqNr(), in.getSenderId()); - out.setCompletePayloadLength(in.payload_length_); + u_int32_t len = decipher(out.complete_payload_, out.complete_payload_length_, in.payload_ , in.payload_length_, in.getSeqNr(), in.getSenderId()); + out.setCompletePayloadLength(len); } //******* NullCipher ******* -void NullCipher::cipher(u_int8_t * out, u_int8_t * in, u_int32_t length, seq_nr_t seq_nr, sender_id_t sender_id) +u_int32_t NullCipher::cipher(u_int8_t* in, u_int32_t ilen, u_int8_t* out, u_int32_t olen, seq_nr_t seq_nr, sender_id_t sender_id) { - std::memcpy(out, in, length ); + std::memcpy(out, in, (ilen < olen) ? ilen : olen); + return (ilen < olen) ? ilen : olen; } +u_int32_t NullCipher::decipher(u_int8_t* in, u_int32_t ilen, u_int8_t* out, u_int32_t olen, seq_nr_t seq_nr, sender_id_t sender_id) +{ + std::memcpy(out, in, (ilen < olen) ? ilen : olen); + return (ilen < olen) ? ilen : olen; +} //****** AesIcmCipher ****** @@ -94,11 +100,27 @@ void AesIcmCipher::setSalt(Buffer salt) salt_ = salt; } -void AesIcmCipher::cipher(u_int8_t * out, u_int8_t * in, u_int32_t length, seq_nr_t seq_nr, sender_id_t sender_id) +u_int32_t AesIcmCipher::cipher(u_int8_t* in, u_int32_t ilen, u_int8_t* out, u_int32_t olen, seq_nr_t seq_nr, sender_id_t sender_id) { - gcry_error_t err; + calc(in, ilen, out, olen, seq_nr, sender_id); + return (ilen < olen) ? ilen : olen; +} - // set the IV +u_int32_t AesIcmCipher::decipher(u_int8_t* in, u_int32_t ilen, u_int8_t* out, u_int32_t olen, seq_nr_t seq_nr, sender_id_t sender_id) +{ + calc(in, ilen, out, olen, seq_nr, sender_id); + return (ilen < olen) ? ilen : olen; +} + +void AesIcmCipher::calc(u_int8_t* in, u_int32_t ilen, u_int8_t* out, u_int32_t olen, seq_nr_t seq_nr, sender_id_t sender_id) +{ + gcry_error_t err = gcry_cipher_reset( cipher_ ); + if( err ) { + cLog.msg(Log::PRIO_ERR) << "AesIcmCipher: Failed to reset cipher: " << gpg_strerror( err ); + return; + } + + // set the IV ( = CTR) //========================================================================== // // 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. @@ -106,33 +128,21 @@ void AesIcmCipher::cipher(u_int8_t * out, u_int8_t * in, u_int32_t length, seq_ // // IV = (k_s * 2^16) XOR (SSRC * 2^64) XOR (i * 2^16) // // sizeof(k_s) = 112 bit, random - Mpi iv(128); // TODO: hardcoded size + Mpi ctr(128); // TODO: hardcoded size Mpi salt = Mpi(salt_.getBuf(), salt_.getLength()); - Mpi sid = sender_id; + Mpi sid = sender_id; // Q@OTTI add mux to sender_id???? Mpi seq = seq_nr; - iv = salt.mul2exp(16) ^ sid.mul2exp(64) ^ seq.mul2exp(16); // TODO: hardcoded size - - u_int8_t *iv_buf = iv.getNewBuf(16); // TODO: hardcoded size - - // Q@NINE -> CTR Mode -> gcry_cipher_setctr() ???? - - err = gcry_cipher_setiv( cipher_, iv_buf, 16 ); // TODO: hardcoded size - delete[] iv_buf; + ctr = salt.mul2exp(16) ^ sid.mul2exp(64) ^ seq.mul2exp(16); // TODO: hardcoded size + u_int8_t *ctr_buf = ctr.getNewBuf(16); // TODO: hardcoded size + err = gcry_cipher_setctr( cipher_, ctr_buf, 16 ); // TODO: hardcoded size + delete[] ctr_buf; if( err ) { - cLog.msg(Log::PRIO_ERR) << "AesIcmCipher: Failed to set cipher IV: " << gpg_strerror( err ); - return; - } - - // Q@NINE -> reset clears IV ???? - - err = gcry_cipher_reset( cipher_ ); - if( err ) { - cLog.msg(Log::PRIO_ERR) << "AesIcmCipher: Failed to reset cipher: " << gpg_strerror( err ); + cLog.msg(Log::PRIO_ERR) << "AesIcmCipher: Failed to set cipher CTR: " << gpg_strerror( err ); return; } - err = gcry_cipher_encrypt( cipher_, out, length, in, length ); + err = gcry_cipher_encrypt( cipher_, out, olen, in, ilen ); if( err ) { cLog.msg(Log::PRIO_ERR) << "AesIcmCipher: Failed to generate cipher bitstream: " << gpg_strerror( err ); return; |