#include <stdio.h>
#include <string.h>
#include <openssl/evp.h>
#if OPENSSL_VERSION_NUMBER >= 0x30000000L
#include <openssl/params.h>
#endif

/* Macros */
#define BUFFER_SIZE	32768

/* Encryption functions */
#define TYPE_MD		0x010
#define TYPE_HMAC	0x020
#define TYPE_CMAC	0x040
#define TYPE_MAC	0x080
#define TYPE_ENCRYPT	0x100
#define TYPE_DECRYPT	0x200

    if (type == TYPE_ENCRYPT) {
	res = EVP_EncryptUpdate(ctx, outbuf, out_len, data, data_len);
    } else {
	res = EVP_DecryptUpdate(ctx, outbuf, out_len, data, data_len);
    }

    if (res) {

	return TCL_OK;
    } else {
	Tcl_AppendResult(interp, "Update failed: ", REASON(), NULL);
	return TCL_ERROR;
    }
}

    if (type == TYPE_ENCRYPT) {
	res = EVP_EncryptFinal_ex(ctx, outbuf, out_len);
    } else {
	res = EVP_DecryptFinal_ex(ctx, outbuf, out_len);
    }

    if (res) {

	return TCL_OK;
    } else {
	Tcl_AppendResult(interp, "Finalize failed: ", REASON(), NULL);
	return TCL_ERROR;
    }
}

 *	Sets result or error message
 *
 *-------------------------------------------------------------------
 */
int EncryptDataHandler(Tcl_Interp *interp, int type, Tcl_Obj *dataObj, Tcl_Obj *cipherObj,
	Tcl_Obj *digestObj, Tcl_Obj *keyObj, Tcl_Obj *ivObj) {
    EVP_CIPHER_CTX *ctx = NULL;
    int data_len = 0, out_len = 0, len = 0, res = TCL_OK;
    unsigned char *data, *outbuf;
    Tcl_Obj *resultObj;

    dprintf("Called");

    /* Get data */
    if (dataObj != NULL) {

	Tcl_AppendResult(interp, "Memory allocation error", (char *) NULL);
	return TCL_ERROR;
    }

    /* Perform operation */
    if (EncryptInitialize(interp, type, &ctx, cipherObj, keyObj, ivObj) != TCL_OK ||
	EncryptUpdate(interp, type, ctx, outbuf, &out_len, data, data_len) != TCL_OK ||
	EncryptFinalize(interp, type, ctx, outbuf+out_len, &len) != TCL_OK) {
	res = TCL_ERROR;
	goto done;
    }
    out_len += len;

done:
    /* Set output result */
    if (res == TCL_OK) {
	outbuf = Tcl_SetByteArrayLength(resultObj, out_len);
	Tcl_SetObjResult(interp, resultObj);
    } else {
	Tcl_DecrRefCount(resultObj);
	/* Result is error message */
    }

    /* Clean up */
    if (ctx != NULL) {
	EVP_CIPHER_CTX_free(ctx);
    }
    return res;
}

/*******************************************************************/

/*
 *-------------------------------------------------------------------
 *
 * EncryptFileHandler --
 *
 *	Perform encryption function on a block of data and return result.
 *
 * Returns:
 *	TCL_OK or TCL_ERROR
 *
 * Side effects:
 *	Encrypts or decrypts inFile data to outFile and sets result to
 *	size of outFile, or an error message.
 *
 *-------------------------------------------------------------------
 */
int EncryptFileHandler(Tcl_Interp *interp, int type, Tcl_Obj *inFileObj, Tcl_Obj *outFileObj,
	Tcl_Obj *cipherObj, Tcl_Obj *digestObj, Tcl_Obj *keyObj, Tcl_Obj *ivObj) {
    EVP_CIPHER_CTX *ctx = NULL;
    int total = 0, res, out_len = 0, len;
    Tcl_Channel in = NULL, out = NULL;
    unsigned char in_buf[BUFFER_SIZE];
    unsigned char out_buf[BUFFER_SIZE+1024];

    dprintf("Called");

    /* Open input file */
    if ((in = Tcl_FSOpenFileChannel(interp, inFileObj, "rb", 0444)) == (Tcl_Channel) NULL) {
	return TCL_ERROR;
    }

    /* Open output file */
    if ((out = Tcl_FSOpenFileChannel(interp, outFileObj, "wb", 0644)) == (Tcl_Channel) NULL) {
	Tcl_Close(interp, in);
	return TCL_ERROR;
    }

    /* Initialize operation */
    if ((res = EncryptInitialize(interp, type, &ctx, cipherObj, keyObj, ivObj)) != TCL_OK) {
	goto done;
    }

    /* Read file data from inFile, encrypt/decrypt it, then output to outFile */
    while (!Tcl_Eof(in)) {
	int read = Tcl_ReadRaw(in, (char *) in_buf, BUFFER_SIZE);
	if (read > 0) {
	    if ((res = EncryptUpdate(interp, type, ctx, out_buf, &out_len, in_buf, read)) == TCL_OK) {
		if (out_len > 0) {
		    len = Tcl_WriteRaw(out, (const char *) out_buf, out_len);
		    if (len >= 0) {
			total += len;
		    } else {
			Tcl_AppendResult(interp, "Write error: ", Tcl_ErrnoMsg(Tcl_GetErrno()), (char *) NULL);
			res = TCL_ERROR;
			goto done;
		    }
		}
	    } else {
		goto done;
	    }
	} else if (read < 0) {
	    Tcl_AppendResult(interp, "Read error: ", Tcl_ErrnoMsg(Tcl_GetErrno()), (char *) NULL);
	    res = TCL_ERROR;
	    goto done;
	}
    }

    /* Finalize data and write any remaining data in block */
    if ((res = EncryptFinalize(interp, type, ctx, out_buf, &out_len)) == TCL_OK) {
	if (out_len > 0) {
	    len = Tcl_WriteRaw(out, (const char *) out_buf, out_len);
	    if (len >= 0) {
		total += len;
	    } else {
		Tcl_AppendResult(interp, "Write error: ", Tcl_ErrnoMsg(Tcl_GetErrno()), (char *) NULL);
		res = TCL_ERROR;
		goto done;
	    }
	}
	Tcl_SetObjResult(interp, Tcl_NewIntObj(total));
    } else {
	goto done;
    }

done:
    /* Clean up */
    if (in != NULL) {
	Tcl_Close(interp, in);
    }
    if (out != NULL) {
	Tcl_Close(interp, out);
    }
    if (ctx != NULL) {
	EVP_CIPHER_CTX_free(ctx);
    }
    return res;
}

/*******************************************************************/

    dprintf("Called");

    /* Clear interp result */
    Tcl_ResetResult(interp);

    /* Validate arg count */
    if (objc < 3 || objc > 12) {
	Tcl_WrongNumArgs(interp, 1, objv, "-cipher name ?-digest name? -key key ?-iv string? [-infile filename -outfile filename | -data data]");
	return TCL_ERROR;
    }

    /* Get options */
    for (int idx = 1; idx < objc; idx++) {
	opt = Tcl_GetStringFromObj(objv[idx], NULL);

	if (opt[0] != '-') {
	    break;
	}

	OPTOBJ("-cipher", cipherObj);
	OPTOBJ("-data", dataObj);
	OPTOBJ("-digest", digestObj);
	OPTOBJ("-infile", inFileObj);
	OPTOBJ("-outfile", outFileObj);
	OPTOBJ("-key", keyObj);
	OPTOBJ("-iv", ivObj);

	OPTBAD("option", "-cipher, -data, -digest, -infile, -key, -iv, -outfile");
	return TCL_ERROR;
    }

    /* Check for required options */
    if (cipherObj == NULL) {
	Tcl_AppendResult(interp, "No cipher", NULL);
    } else if (keyObj == NULL) {
	Tcl_AppendResult(interp, "No key", NULL);
	return TCL_ERROR;
    }

    /* Perform encryption function on file, stacked channel, using instance command, or data blob */
    if (inFileObj != NULL && outFileObj != NULL) {
	res = EncryptFileHandler(interp, type, inFileObj, outFileObj, cipherObj, digestObj, keyObj, ivObj);
    } else if (dataObj != NULL) {
	res = EncryptDataHandler(interp, type, dataObj, cipherObj, digestObj, keyObj, ivObj);
    } else {
	Tcl_AppendResult(interp, "No operation specified: Use -data, -infile, or -outfile option", NULL);
	res = TCL_ERROR;
    }
    return res;
}

/*
 *-------------------------------------------------------------------