diff --git a/main.c b/main.c
index 28925e0..d4497f8 100755
--- a/main.c
+++ b/main.c
@@ -847,12 +847,120 @@ END;\
 	oraAllInOne->blob = 0;
 }
 
+ub4 RemoteCrc32(struct ORACLEALLINONE *oraAllInOne, char* pDirectory, char* pRemoteFile)
+{
+	ub4 crc32;
+
+	struct BINDVARIABLE oraBindsCrc32[] =
+	{
+		{ 0, SQLT_STR, ":directory", pDirectory,  ORA_IDENTIFIER_SIZE + 1 },
+		{ 0, SQLT_STR, ":filename",  pRemoteFile, MAX_FMT_SIZE            },
+		{ 0, SQLT_BIN, ":crc32",     &crc32,      sizeof(crc32)           }
+	};
+
+	struct ORACLESTATEMENT oraStmtCrc32 = { "\
+DECLARE\
+	f_handle UTL_FILE.FILE_TYPE;\
+	TYPE arr_t IS VARRAY(256) OF RAW(4) NOT NULL;\
+	crc32precalc CONSTANT arr_t := arr_t(\
+'00000000', '77073096', 'ee0e612c', '990951ba', '076dc419', '706af48f', 'e963a535', '9e6495a3',\
+'0edb8832', '79dcb8a4', 'e0d5e91e', '97d2d988', '09b64c2b', '7eb17cbd', 'e7b82d07', '90bf1d91',\
+'1db71064', '6ab020f2', 'f3b97148', '84be41de', '1adad47d', '6ddde4eb', 'f4d4b551', '83d385c7',\
+'136c9856', '646ba8c0', 'fd62f97a', '8a65c9ec', '14015c4f', '63066cd9', 'fa0f3d63', '8d080df5',\
+'3b6e20c8', '4c69105e', 'd56041e4', 'a2677172', '3c03e4d1', '4b04d447', 'd20d85fd', 'a50ab56b',\
+'35b5a8fa', '42b2986c', 'dbbbc9d6', 'acbcf940', '32d86ce3', '45df5c75', 'dcd60dcf', 'abd13d59',\
+'26d930ac', '51de003a', 'c8d75180', 'bfd06116', '21b4f4b5', '56b3c423', 'cfba9599', 'b8bda50f',\
+'2802b89e', '5f058808', 'c60cd9b2', 'b10be924', '2f6f7c87', '58684c11', 'c1611dab', 'b6662d3d',\
+'76dc4190', '01db7106', '98d220bc', 'efd5102a', '71b18589', '06b6b51f', '9fbfe4a5', 'e8b8d433',\
+'7807c9a2', '0f00f934', '9609a88e', 'e10e9818', '7f6a0dbb', '086d3d2d', '91646c97', 'e6635c01',\
+'6b6b51f4', '1c6c6162', '856530d8', 'f262004e', '6c0695ed', '1b01a57b', '8208f4c1', 'f50fc457',\
+'65b0d9c6', '12b7e950', '8bbeb8ea', 'fcb9887c', '62dd1ddf', '15da2d49', '8cd37cf3', 'fbd44c65',\
+'4db26158', '3ab551ce', 'a3bc0074', 'd4bb30e2', '4adfa541', '3dd895d7', 'a4d1c46d', 'd3d6f4fb',\
+'4369e96a', '346ed9fc', 'ad678846', 'da60b8d0', '44042d73', '33031de5', 'aa0a4c5f', 'dd0d7cc9',\
+'5005713c', '270241aa', 'be0b1010', 'c90c2086', '5768b525', '206f85b3', 'b966d409', 'ce61e49f',\
+'5edef90e', '29d9c998', 'b0d09822', 'c7d7a8b4', '59b33d17', '2eb40d81', 'b7bd5c3b', 'c0ba6cad',\
+'edb88320', '9abfb3b6', '03b6e20c', '74b1d29a', 'ead54739', '9dd277af', '04db2615', '73dc1683',\
+'e3630b12', '94643b84', '0d6d6a3e', '7a6a5aa8', 'e40ecf0b', '9309ff9d', '0a00ae27', '7d079eb1',\
+'f00f9344', '8708a3d2', '1e01f268', '6906c2fe', 'f762575d', '806567cb', '196c3671', '6e6b06e7',\
+'fed41b76', '89d32be0', '10da7a5a', '67dd4acc', 'f9b9df6f', '8ebeeff9', '17b7be43', '60b08ed5',\
+'d6d6a3e8', 'a1d1937e', '38d8c2c4', '4fdff252', 'd1bb67f1', 'a6bc5767', '3fb506dd', '48b2364b',\
+'d80d2bda', 'af0a1b4c', '36034af6', '41047a60', 'df60efc3', 'a867df55', '316e8eef', '4669be79',\
+'cb61b38c', 'bc66831a', '256fd2a0', '5268e236', 'cc0c7795', 'bb0b4703', '220216b9', '5505262f',\
+'c5ba3bbe', 'b2bd0b28', '2bb45a92', '5cb36a04', 'c2d7ffa7', 'b5d0cf31', '2cd99e8b', '5bdeae1d',\
+'9b64c2b0', 'ec63f226', '756aa39c', '026d930a', '9c0906a9', 'eb0e363f', '72076785', '05005713',\
+'95bf4a82', 'e2b87a14', '7bb12bae', '0cb61b38', '92d28e9b', 'e5d5be0d', '7cdcefb7', '0bdbdf21',\
+'86d3d2d4', 'f1d4e242', '68ddb3f8', '1fda836e', '81be16cd', 'f6b9265b', '6fb077e1', '18b74777',\
+'88085ae6', 'ff0f6a70', '66063bca', '11010b5c', '8f659eff', 'f862ae69', '616bffd3', '166ccf45',\
+'a00ae278', 'd70dd2ee', '4e048354', '3903b3c2', 'a7672661', 'd06016f7', '4969474d', '3e6e77db',\
+'aed16a4a', 'd9d65adc', '40df0b66', '37d83bf0', 'a9bcae53', 'debb9ec5', '47b2cf7f', '30b5ffe9',\
+'bdbdf21c', 'cabac28a', '53b39330', '24b4a3a6', 'bad03605', 'cdd70693', '54de5729', '23d967bf',\
+'b3667a2e', 'c4614ab8', '5d681b02', '2a6f2b94', 'b40bbe37', 'c30c8ea1', '5a05df1b', '2d02ef8d');\
+	raw_buffer RAW(16384);\
+	crc RAW(4);\
+BEGIN\
+	crc := 'ffffffff';\
+	f_handle := UTL_FILE.FOPEN(:directory, :filename, 'rb');\
+	LOOP\
+		BEGIN\
+			UTL_FILE.GET_RAW(f_handle, raw_buffer, 16384);\
+			FOR c in 1..UTL_RAW.LENGTH(raw_buffer) LOOP\
+				crc := UTL_RAW.BIT_XOR(UTL_RAW.CONCAT('00', UTL_RAW.SUBSTR(crc, 1, 3)),\
+				                       crc32precalc(UTL_RAW.CAST_TO_BINARY_INTEGER(UTL_RAW.BIT_XOR(UTL_RAW.SUBSTR(crc, 4, 1), UTL_RAW.SUBSTR(raw_buffer, c, 1))) + 1));\
+			END LOOP;\
+		EXCEPTION\
+			WHEN NO_DATA_FOUND THEN\
+				EXIT;\
+		END;\
+	END LOOP;\
+	UTL_FILE.FCLOSE(f_handle);\
+	:crc32 := UTL_RAW.BIT_COMPLEMENT(crc);\
+END;",
+	       0, oraBindsCrc32, sizeof(oraBindsCrc32)/sizeof(struct BINDVARIABLE), 0, 0 };
+
+	PrepareStmtAndBind(oraAllInOne, &oraStmtCrc32);
+
+	if (ExecuteStmt(oraAllInOne))
+		ExitWithError(oraAllInOne, 4, ERROR_OCI, "Failed to calculate CRC32 on file in oracle directory\n");
+
+	ReleaseStmt(oraAllInOne);
+
+	return crc32;
+}
+
+ub4 LocalCrc32(struct ORACLEALLINONE *oraAllInOne, char* pLocalFile)
+{
+	FILE *fp;
+	unsigned char vBuffer[ORA_RAW_BUFFER_SIZE];
+	ub4 vActualSize;
+	uLong crc;
+
+	crc = crc32(0L, Z_NULL, 0);
+	if ((fp = fopen(pLocalFile, "rb")) == NULL)
+	{
+		ExitWithError(oraAllInOne, 4, ERROR_OS, "Error opening a local file for reading\n");
+	}
+
+	while (vActualSize = fread(vBuffer, sizeof(unsigned char), sizeof(vBuffer), fp))
+	{
+		if (ferror(fp))
+		{
+			fclose(fp);
+			ExitWithError(oraAllInOne, 4, ERROR_OS, "Error reading from a local file\n");
+		}
+		crc = crc32(crc, vBuffer, vActualSize);
+	}
+	fclose(fp);
+
+	return crc;
+}
+
 struct PROGRAM_OPTIONS
 {
 	enum PROGRAM_ACTION programAction;
 	const char* lsDirectoryName;
 	int compressionLevel;
 	int isBackground;
+	int isVerify;
 	const char* connectionString;
 };
 
@@ -949,6 +1057,7 @@ SELECT t.file_name,\
 		{ "list-directories", '\0', POPT_ARG_NONE, 0, ACTION_LSDIR, "List Oracle directories" },
 		{ "ls", '\0', POPT_ARG_STRING, &programOptions.lsDirectoryName, ACTION_LS, "List files in Oracle directory", "DIRECTORY" },
 		{ "rm", '\0', POPT_ARG_NONE, 0, ACTION_RM, "Remove file from Oracle directory" },
+		{ "verify", 'c', POPT_ARG_VAL, &programOptions.isVerify, 1, "Verify files by CRC32 after copy" },
 		{ NULL, '\0', POPT_ARG_INCLUDE_TABLE, compressionOptions, 0, "Compression options:" },
 		{ NULL, '\0', POPT_ARG_INCLUDE_TABLE, objOptions, 0, "Database objects for --ls support:" },
 		POPT_AUTOHELP
@@ -959,6 +1068,7 @@ SELECT t.file_name,\
 	programOptions.lsDirectoryName = 0;
 	programOptions.compressionLevel = 0;
 	programOptions.isBackground = 0;
+	programOptions.isVerify = 0;
 	programOptions.connectionString = 0;
 
 	poptcon = poptGetContext(NULL, argc, argv, options, 0);
@@ -1014,6 +1124,12 @@ SELECT t.file_name,\
 		ExitWithUsage(&poptcon);
 	}
 
+	if (programOptions.isVerify && programOptions.programAction != ACTION_READ && programOptions.programAction != ACTION_WRITE)
+	{
+		fprintf(stderr, "Verify mode can only be specified for transfer mode\n");
+		ExitWithUsage(&poptcon);
+	}
+
 	programOptions.connectionString = poptGetArg(poptcon);
 	if (!programOptions.connectionString)
 	{
@@ -1217,12 +1333,18 @@ SELECT t.file_name,\
 			DownloadFileWithCompression(&oraAllInOne, vDirectory, programOptions.compressionLevel, vRemoteFile, vLocalFile);
 		else
 			TransferFile(&oraAllInOne, 1, vDirectory, vRemoteFile, vLocalFile);
+		if (programOptions.isVerify &&
+		    RemoteCrc32(&oraAllInOne, vDirectory, vRemoteFile) != LocalCrc32(&oraAllInOne, vLocalFile))
+			ExitWithError(&oraAllInOne, 0, ERROR_NONE, "Verify failed");
 		break;
 	case ACTION_WRITE:
 		if (programOptions.compressionLevel > 0)
 			UploadFileWithCompression(&oraAllInOne, vDirectory, programOptions.compressionLevel, vRemoteFile, vLocalFile);
 		else
 			TransferFile(&oraAllInOne, 0, vDirectory, vRemoteFile, vLocalFile);
+		if (programOptions.isVerify &&
+		    RemoteCrc32(&oraAllInOne, vDirectory, vRemoteFile) != LocalCrc32(&oraAllInOne, vLocalFile))
+			ExitWithError(&oraAllInOne, 0, ERROR_NONE, "Verify failed");
 		break;
 	case ACTION_LSDIR:
 		LsDir(&oraAllInOne);