From 1c564fb2967acc00fe3fcf10c2ab1dab055349f4 Mon Sep 17 00:00:00 2001 From: sawinglogz <3787776-sawinglogz@users.noreply.gitlab.com> Date: Wed, 15 May 2019 15:16:14 -0400 Subject: [PATCH] Calculate and check PRS1 CRC16 on V2 files. --- oscar/SleepLib/loader_plugins/prs1_loader.cpp | 157 ++++++++++-------- oscar/SleepLib/loader_plugins/prs1_loader.h | 7 +- 2 files changed, 97 insertions(+), 67 deletions(-) diff --git a/oscar/SleepLib/loader_plugins/prs1_loader.cpp b/oscar/SleepLib/loader_plugins/prs1_loader.cpp index eedba61e..62ab8f0d 100644 --- a/oscar/SleepLib/loader_plugins/prs1_loader.cpp +++ b/oscar/SleepLib/loader_plugins/prs1_loader.cpp @@ -43,61 +43,55 @@ QHash ModelMap; -#define PRS1_CRC_CHECK -#ifdef PRS1_CRC_CHECK -typedef quint16 crc_t; +// CRC-16/KERMIT, polynomial: 0x11021, bit reverse algorithm +// Table generated by crcmod (crc-kermit) -static const crc_t crc_table[256] = { - 0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf, - 0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7, - 0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e, - 0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876, - 0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd, - 0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5, - 0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c, - 0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974, - 0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb, - 0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3, - 0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a, - 0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72, - 0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9, - 0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1, - 0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738, - 0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70, - 0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7, - 0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff, - 0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036, - 0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e, - 0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5, - 0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd, - 0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134, - 0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c, - 0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3, - 0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb, - 0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232, - 0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a, - 0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1, - 0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9, - 0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330, - 0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78 -}; - -crc_t CRC16(const unsigned char *data, size_t data_len) +typedef quint16 crc16_t; +static crc16_t CRC16(unsigned char * data, size_t data_len, crc16_t crc=0) { - crc_t crc = 0; - unsigned int tbl_idx; - - while (data_len--) { - tbl_idx = (crc ^ *data) & 0xff; - crc = (crc_table[tbl_idx] ^ (crc >> 8)) & 0xffff; + static const crc16_t table[256] = { + 0x0000U, 0x1189U, 0x2312U, 0x329bU, 0x4624U, 0x57adU, 0x6536U, 0x74bfU, + 0x8c48U, 0x9dc1U, 0xaf5aU, 0xbed3U, 0xca6cU, 0xdbe5U, 0xe97eU, 0xf8f7U, + 0x1081U, 0x0108U, 0x3393U, 0x221aU, 0x56a5U, 0x472cU, 0x75b7U, 0x643eU, + 0x9cc9U, 0x8d40U, 0xbfdbU, 0xae52U, 0xdaedU, 0xcb64U, 0xf9ffU, 0xe876U, + 0x2102U, 0x308bU, 0x0210U, 0x1399U, 0x6726U, 0x76afU, 0x4434U, 0x55bdU, + 0xad4aU, 0xbcc3U, 0x8e58U, 0x9fd1U, 0xeb6eU, 0xfae7U, 0xc87cU, 0xd9f5U, + 0x3183U, 0x200aU, 0x1291U, 0x0318U, 0x77a7U, 0x662eU, 0x54b5U, 0x453cU, + 0xbdcbU, 0xac42U, 0x9ed9U, 0x8f50U, 0xfbefU, 0xea66U, 0xd8fdU, 0xc974U, + 0x4204U, 0x538dU, 0x6116U, 0x709fU, 0x0420U, 0x15a9U, 0x2732U, 0x36bbU, + 0xce4cU, 0xdfc5U, 0xed5eU, 0xfcd7U, 0x8868U, 0x99e1U, 0xab7aU, 0xbaf3U, + 0x5285U, 0x430cU, 0x7197U, 0x601eU, 0x14a1U, 0x0528U, 0x37b3U, 0x263aU, + 0xdecdU, 0xcf44U, 0xfddfU, 0xec56U, 0x98e9U, 0x8960U, 0xbbfbU, 0xaa72U, + 0x6306U, 0x728fU, 0x4014U, 0x519dU, 0x2522U, 0x34abU, 0x0630U, 0x17b9U, + 0xef4eU, 0xfec7U, 0xcc5cU, 0xddd5U, 0xa96aU, 0xb8e3U, 0x8a78U, 0x9bf1U, + 0x7387U, 0x620eU, 0x5095U, 0x411cU, 0x35a3U, 0x242aU, 0x16b1U, 0x0738U, + 0xffcfU, 0xee46U, 0xdcddU, 0xcd54U, 0xb9ebU, 0xa862U, 0x9af9U, 0x8b70U, + 0x8408U, 0x9581U, 0xa71aU, 0xb693U, 0xc22cU, 0xd3a5U, 0xe13eU, 0xf0b7U, + 0x0840U, 0x19c9U, 0x2b52U, 0x3adbU, 0x4e64U, 0x5fedU, 0x6d76U, 0x7cffU, + 0x9489U, 0x8500U, 0xb79bU, 0xa612U, 0xd2adU, 0xc324U, 0xf1bfU, 0xe036U, + 0x18c1U, 0x0948U, 0x3bd3U, 0x2a5aU, 0x5ee5U, 0x4f6cU, 0x7df7U, 0x6c7eU, + 0xa50aU, 0xb483U, 0x8618U, 0x9791U, 0xe32eU, 0xf2a7U, 0xc03cU, 0xd1b5U, + 0x2942U, 0x38cbU, 0x0a50U, 0x1bd9U, 0x6f66U, 0x7eefU, 0x4c74U, 0x5dfdU, + 0xb58bU, 0xa402U, 0x9699U, 0x8710U, 0xf3afU, 0xe226U, 0xd0bdU, 0xc134U, + 0x39c3U, 0x284aU, 0x1ad1U, 0x0b58U, 0x7fe7U, 0x6e6eU, 0x5cf5U, 0x4d7cU, + 0xc60cU, 0xd785U, 0xe51eU, 0xf497U, 0x8028U, 0x91a1U, 0xa33aU, 0xb2b3U, + 0x4a44U, 0x5bcdU, 0x6956U, 0x78dfU, 0x0c60U, 0x1de9U, 0x2f72U, 0x3efbU, + 0xd68dU, 0xc704U, 0xf59fU, 0xe416U, 0x90a9U, 0x8120U, 0xb3bbU, 0xa232U, + 0x5ac5U, 0x4b4cU, 0x79d7U, 0x685eU, 0x1ce1U, 0x0d68U, 0x3ff3U, 0x2e7aU, + 0xe70eU, 0xf687U, 0xc41cU, 0xd595U, 0xa12aU, 0xb0a3U, 0x8238U, 0x93b1U, + 0x6b46U, 0x7acfU, 0x4854U, 0x59ddU, 0x2d62U, 0x3cebU, 0x0e70U, 0x1ff9U, + 0xf78fU, 0xe606U, 0xd49dU, 0xc514U, 0xb1abU, 0xa022U, 0x92b9U, 0x8330U, + 0x7bc7U, 0x6a4eU, 0x58d5U, 0x495cU, 0x3de3U, 0x2c6aU, 0x1ef1U, 0x0f78U, + }; + for (size_t i=0; i < data_len; i++) { + crc = table[(*data ^ (unsigned char)crc) & 0xFF] ^ (crc >> 8); data++; } - - return crc & 0xffff; + return crc; } -#endif + enum FlexMode { FLEX_None, FLEX_CFlex, FLEX_CFlexPlus, FLEX_AFlex, FLEX_RiseTime, FLEX_BiFlex, FLEX_Unknown }; @@ -3479,7 +3473,12 @@ PRS1DataChunk* PRS1DataChunk::ParseNext(QFile & f) break; } - // TODO: move block CRC comparison here + // Make sure the calculated CRC over the entire chunk (header and data) matches the stored CRC. + if (chunk->calcCrc != chunk->storedCrc) { + // corrupt data block.. bleh.. + qDebug() << chunk->m_path << "@" << chunk->m_filepos << "block CRC calc" << hex << chunk->calcCrc << "!= stored" << hex << chunk->storedCrc; + //break; // don't break to avoid changing behavior (for now) + } // Only return the chunk if it has passed all tests above. out_chunk = chunk; @@ -3494,14 +3493,15 @@ bool PRS1DataChunk::ReadHeader(QFile & f) { bool ok = false; do { + // Read common header fields. this->m_filepos = f.pos(); this->m_header = f.read(15); if (this->m_header.size() != 15) { qWarning() << this->m_path << "file too short?"; break; } + unsigned char * header = (unsigned char *)this->m_header.data(); - this->fileVersion = header[0]; // Correlates to DataFileVersion in PROP[erties].TXT, only 2 or 3 has ever been observed this->blockSize = (header[2] << 8) | header[1]; this->htype = header[3]; // 00 = normal, 01=waveform @@ -3511,16 +3511,17 @@ bool PRS1DataChunk::ReadHeader(QFile & f) this->sessionid = (header[10] << 24) | (header[9] << 16) | (header[8] << 8) | header[7]; this->timestamp = (header[14] << 24) | (header[13] << 16) | (header[12] << 8) | header[11]; + // Do a few early sanity checks before any variable-length header data. if (this->blockSize == 0) { qWarning() << this->m_path << "blocksize 0?"; break; } - if (this->fileVersion < 2 || this->fileVersion > 3) { qWarning() << this->m_path << "Never seen PRS1 header version < 2 or > 3 before"; break; } + // Read format-specific variable-length header data. bool hdr_ok = false; if (this->ext < 5) { // Not a waveform chunk switch (this->fileVersion) { @@ -3681,29 +3682,29 @@ bool PRS1DataChunk::ReadData(QFile & f) do { // Read data block int data_size = this->blockSize - this->m_header.size(); + if (data_size < 0) { + qWarning() << this->m_path << "chunk size smaller than header"; + break; + } this->m_data = f.read(data_size); if (this->m_data.size() < data_size) { qWarning() << this->m_path << "less data in file than specified in header"; break; } + // Extract the stored CRC from the data buffer and calculate the current CRC. if (this->fileVersion==3) { - //int ds = this->m_data.size(); - //quint32 crc16 = this->m_data.at(ds-2) | this->m_data.at(ds-1) << 8; - this->m_data.chop(4); - } else { - // last two bytes contain crc16 checksum. - int ds = this->m_data.size(); - quint16 crc16 = this->m_data.at(ds-2) | this->m_data.at(ds-1) << 8; - this->m_data.chop(2); -#ifdef PRS1_CRC_CHECK - // This fails.. it needs to include the header! - quint16 calc16 = CRC16((unsigned char *)this->m_data.data(), this->m_data.size()); - if (calc16 != crc16) { - // corrupt data block.. bleh.. - // qDebug() << "CRC16 doesn't match for chunk" << this->sessionid << "for" << path; + // The last 4 bytes contain a CRC32 checksum of the data. + if (!ExtractStoredCrc(4)) { + break; } -#endif + this->calcCrc = this->storedCrc; // TODO + } else { + // The last 2 bytes contain a CRC16 checksum of the data. + if (!ExtractStoredCrc(2)) { + break; + } + this->calcCrc = CRC16((unsigned char *)this->m_data.data(), this->m_data.size()); } ok = true; @@ -3711,6 +3712,30 @@ bool PRS1DataChunk::ReadData(QFile & f) return ok; } + + +bool PRS1DataChunk::ExtractStoredCrc(int size) +{ + // Make sure there's enough data for the CRC. + int offset = this->m_data.size() - size; + if (offset < 0) { + qWarning() << this->m_path << "chunk truncated"; + return false; + } + + // Read the last 16- or 32-bit little-endian integer. + quint32 storedCrc = 0; + unsigned char* data = (unsigned char*)this->m_data.data(); + for (int i=0; i < size; i++) { + storedCrc |= data[offset+i] << (8*i); + } + this->storedCrc = storedCrc; + + // Drop the CRC from the data. + this->m_data.chop(size); + + return true; +} void InitModelMap() diff --git a/oscar/SleepLib/loader_plugins/prs1_loader.h b/oscar/SleepLib/loader_plugins/prs1_loader.h index fd676c84..cb7a59aa 100644 --- a/oscar/SleepLib/loader_plugins/prs1_loader.h +++ b/oscar/SleepLib/loader_plugins/prs1_loader.h @@ -105,7 +105,9 @@ public: QMap hblock; quint8 storedChecksum; // header checksum stored in file, last byte of m_header - quint8 calcChecksum; // header checksum as calculated when parsing + quint8 calcChecksum; // header checksum as calculated when parsing + quint32 storedCrc; // header + data CRC stored in file, last 2-4 bytes of chunk + quint32 calcCrc; // header + data CRC as calculated when parsing //! \brief Parse and return the next chunk from a PRS1 file static PRS1DataChunk* ParseNext(class QFile & f); @@ -125,6 +127,9 @@ protected: //! \brief Read and parse the waveform-specific header data from a PRS1 file bool ReadWaveformHeader(class QFile & f); + + //! \brief Extract the stored CRC from the end of the data of a PRS1 chunk + bool ExtractStoredCrc(int size); }; class PRS1Loader;