void Cryptor::encrypt(const string &plaintext, const Key &key, string *ciphertext) { ALIGN16 unsigned char *schedule = genKeySchedule(key); switch (mode) { case ECB: ecbEncrypt(plaintext, key, ciphertext, schedule); break; case CBC: cbcEncrypt(plaintext, key, ciphertext, schedule); break; case CTR: break; } delete[] schedule; }
error_t tlsWriteRecord(TlsContext *context, size_t length, TlsContentType contentType) { error_t error; uint_t i; size_t paddingLength; //Point to the TLS record TlsRecord *record = (TlsRecord *) context->txBuffer; //Format TLS record record->type = contentType; record->version = htons(context->version); record->length = htons(length); //Debug message TRACE_DEBUG("Sending TLS record...\r\n"); TRACE_DEBUG_ARRAY(" ", record, length + sizeof(TlsRecord)); //Protect record payload? if(context->changeCipherSpecSent) { //Message authentication is required? if(context->hashAlgo) { #if (TLS_MAX_VERSION >= SSL_VERSION_3_0 && TLS_MIN_VERSION <= SSL_VERSION_3_0) //Check whether SSL 3.0 is currently used if(context->version == SSL_VERSION_3_0) { //SSL 3.0 uses an older obsolete version of the HMAC construction error = sslComputeMac(context, context->writeMacKey, context->writeSeqNum, record, record->data, length, record->data + length); //Any error to report? if(error) return error; } else #endif #if (TLS_MAX_VERSION >= TLS_VERSION_1_0 && TLS_MIN_VERSION <= TLS_VERSION_1_2) //Check whether TLS 1.0, TLS 1.1 or TLS 1.2 is currently used if(context->version >= TLS_VERSION_1_0) { //TLS uses a HMAC construction hmacInit(&context->hmacContext, context->hashAlgo, context->writeMacKey, context->macKeyLength); //Compute MAC over the sequence number and the record contents hmacUpdate(&context->hmacContext, context->writeSeqNum, sizeof(TlsSequenceNumber)); hmacUpdate(&context->hmacContext, record, length + sizeof(TlsRecord)); //Append the resulting MAC to the message hmacFinal(&context->hmacContext, record->data + length); } else #endif //The negotiated TLS version is not valid... { //Report an error return ERROR_INVALID_VERSION; } //Debug message TRACE_DEBUG("Write sequence number:\r\n"); TRACE_DEBUG_ARRAY(" ", context->writeSeqNum, sizeof(TlsSequenceNumber)); TRACE_DEBUG("Computed MAC:\r\n"); TRACE_DEBUG_ARRAY(" ", record->data + length, context->hashAlgo->digestSize); //Adjust the length of the message length += context->hashAlgo->digestSize; //Fix length field record->length = htons(length); //Increment sequence number tlsIncSequenceNumber(context->writeSeqNum); } //Encryption is required? if(context->cipherAlgo) { #if (TLS_STREAM_CIPHER_SUPPORT == ENABLED) //Stream cipher? if(context->cipherMode == CIPHER_MODE_STREAM) { //Debug message TRACE_DEBUG("Record before encryption:\r\n"); TRACE_DEBUG_ARRAY(" ", record, length + sizeof(TlsRecord)); //Encrypt record contents context->cipherAlgo->encryptStream(context->writeCipherContext, record->data, record->data, length); } else #endif #if (TLS_CBC_CIPHER_SUPPORT == ENABLED) //CBC block cipher? if(context->cipherMode == CIPHER_MODE_CBC) { #if (TLS_MAX_VERSION >= TLS_VERSION_1_1 && TLS_MIN_VERSION <= TLS_VERSION_1_2) //TLS 1.1 and 1.2 use an explicit IV if(context->version >= TLS_VERSION_1_1) { //Make room for the IV at the beginning of the data memmove(record->data + context->recordIvLength, record->data, length); //The initialization vector should be chosen at random error = context->prngAlgo->read(context->prngContext, record->data, context->recordIvLength); //Any error to report? if(error) return error; //Adjust the length of the message length += context->recordIvLength; } #endif //Get the actual amount of bytes in the last block paddingLength = (length + 1) % context->cipherAlgo->blockSize; //Padding is added to force the length of the plaintext to be //an integral multiple of the cipher's block length if(paddingLength > 0) paddingLength = context->cipherAlgo->blockSize - paddingLength; //Write padding bytes for(i = 0; i <= paddingLength; i++) record->data[length + i] = paddingLength; //Compute the length of the resulting message length += paddingLength + 1; //Fix length field record->length = htons(length); //Debug message TRACE_DEBUG("Record before encryption:\r\n"); TRACE_DEBUG_ARRAY(" ", record, length + sizeof(TlsRecord)); //CBC encryption error = cbcEncrypt(context->cipherAlgo, context->writeCipherContext, context->writeIv, record->data, record->data, length); //Any error to report? if(error) return error; } else #endif #if (TLS_CCM_CIPHER_SUPPORT == ENABLED || TLS_GCM_CIPHER_SUPPORT == ENABLED) //AEAD cipher? if(context->cipherMode == CIPHER_MODE_CCM || context->cipherMode == CIPHER_MODE_GCM) { uint8_t *data; uint8_t *tag; size_t nonceLength; uint8_t nonce[12]; uint8_t a[13]; //Determine the total length of the nonce nonceLength = context->fixedIvLength + context->recordIvLength; //The salt is the implicit part of the nonce and is not sent in the packet memcpy(nonce, context->writeIv, context->fixedIvLength); //The explicit part of the nonce is chosen by the sender error = context->prngAlgo->read(context->prngContext, nonce + context->fixedIvLength, context->recordIvLength); //Any error to report? if(error) return error; //Make room for the explicit nonce at the beginning of the record memmove(record->data + context->recordIvLength, record->data, length); //The explicit part of the nonce is carried in each TLS record memcpy(record->data, nonce + context->fixedIvLength, context->recordIvLength); //Additional data to be authenticated memcpy(a, context->writeSeqNum, sizeof(TlsSequenceNumber)); memcpy(a + sizeof(TlsSequenceNumber), record, sizeof(TlsRecord)); //Plaintext data data = record->data + context->recordIvLength; //Buffer where to store the authentication tag tag = data + length; #if (TLS_CCM_CIPHER_SUPPORT == ENABLED) //CCM cipher mode? if(context->cipherMode == CIPHER_MODE_CCM) { //Authenticated encryption using CCM error = ccmEncrypt(context->cipherAlgo, context->writeCipherContext, nonce, nonceLength, a, 13, data, data, length, tag, context->authTagLength); } else #endif #if (TLS_GCM_CIPHER_SUPPORT == ENABLED) //GCM cipher mode? if(context->cipherMode == CIPHER_MODE_GCM) { //Authenticated encryption using GCM error = gcmEncrypt(context->cipherAlgo, context->writeCipherContext, nonce, nonceLength, a, 13, data, data, length, tag, context->authTagLength); } else #endif //Invalid cipher mode? { //The specified cipher mode is not supported error = ERROR_UNSUPPORTED_CIPHER_MODE; } //Failed to encrypt data? if(error) return error; //Compute the length of the resulting message length += context->recordIvLength + context->authTagLength; //Fix length field record->length = htons(length); //Increment sequence number tlsIncSequenceNumber(context->writeSeqNum); } else #endif //Invalid cipher mode? { //The specified cipher mode is not supported return ERROR_UNSUPPORTED_CIPHER_MODE; } //Debug message TRACE_DEBUG("Encrypted record:\r\n"); TRACE_DEBUG_ARRAY(" ", record, length + sizeof(TlsRecord)); } } //Compute the length of the complete TLS record length += sizeof(TlsRecord); //Send TLS record return tlsIoWrite(context, record, length); }