#include "tlsInt.h"
#include "tclOpts.h"
#include <tcl.h>
#include <stdio.h>
#include <string.h>
#include <openssl/evp.h>
#include <openssl/cmac.h>
#include <openssl/hmac.h>

/* Constants */
const char *hex = "0123456789ABCDEF";

/* Macros */
#define BUFFER_SIZE 65536
#define BIN_FORMAT 0
#define HEX_FORMAT 1
#define CHAN_EOF 0x10
#define TYPE_MD    0x20
#define TYPE_HMAC  0x40
#define TYPE_CMAC  0x80

/*
 * This structure defines the per-instance state of a digest operation.
 */
typedef struct DigestState {
	Tcl_Channel self;	/* This socket channel */
	Tcl_TimerToken timer;	/* Timer for read events */

	int flags;		/* Chan config flags */
	int watchMask;		/* Current WatchProc mask */
	int mode;		/* Current mode of parent channel */
	int format;		/* Digest format and operation */

	Tcl_Interp *interp;	/* Current interpreter */
	EVP_MD_CTX *ctx;	/* MD Context */
	HMAC_CTX *hctx;		/* HMAC Context */
	CMAC_CTX *cctx;		/* CMAC Context */
	Tcl_Command token;	/* Command token */
} DigestState;

/*
 *-------------------------------------------------------------------
 *
 * Tls_DigestNew --

    if (statePtr != NULL) {
	memset(statePtr, 0, sizeof(DigestState));
	statePtr->self	= NULL;		/* This socket channel */
	statePtr->timer = NULL;		/* Timer to flush data */
	statePtr->flags = 0;		/* Chan config flags */
	statePtr->watchMask = 0;	/* Current WatchProc mask */
	statePtr->mode	= 0;		/* Current mode of parent channel */
	statePtr->format = format;	/* Digest format and operation */
	statePtr->interp = interp;	/* Current interpreter */
	statePtr->ctx = NULL;		/* MD Context */
	statePtr->hctx = NULL;		/* HMAC Context */
	statePtr->cctx = NULL;		/* CMAC Context */
	statePtr->token = NULL;		/* Command token */
    }
    return statePtr;
}

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

    if (statePtr->ctx != (EVP_MD_CTX *) NULL) {
	EVP_MD_CTX_free(statePtr->ctx);
    }
    if (statePtr->hctx != (HMAC_CTX *) NULL) {
	HMAC_CTX_free(statePtr->hctx);
    }
    if (statePtr->cctx != (CMAC_CTX *) NULL) {
	CMAC_CTX_free(statePtr->cctx);
    }
    ckfree(statePtr);
}

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

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

 *
 * Side effects:
 *	No result or error message
 *
 *-------------------------------------------------------------------
 */
int Tls_DigestInit(Tcl_Interp *interp, DigestState *statePtr, const EVP_MD *md,
	const EVP_CIPHER *cipher, Tcl_Obj *keyObj) {
    int key_len, res = 0;
    const unsigned char *key;

    /* Create message digest context */
    if (statePtr->format & TYPE_MD) {
	statePtr->ctx = EVP_MD_CTX_new();
	res = (statePtr->ctx != NULL);
    } else if (statePtr->format & TYPE_HMAC) {
	statePtr->hctx = HMAC_CTX_new();
	res = (statePtr->hctx != NULL);
    } else if (statePtr->format & TYPE_CMAC) {
	statePtr->cctx = CMAC_CTX_new();
	res = (statePtr->cctx != NULL);
    }
    if (!res) {
	Tcl_AppendResult(interp, "Create digest context failed: ", REASON(), NULL);
	return TCL_ERROR;
    }

    /* Initialize hash function */
    if (statePtr->format & TYPE_MD) {
	res = EVP_DigestInit_ex(statePtr->ctx, md, NULL);
    } else if (statePtr->format & TYPE_HMAC) {
	key = Tcl_GetByteArrayFromObj(keyObj, &key_len);
	res = HMAC_Init_ex(statePtr->hctx, (const void *) key, key_len, md, NULL);
    } else if (statePtr->format & TYPE_CMAC) {
	key = Tcl_GetByteArrayFromObj(keyObj, &key_len);
	res = CMAC_Init(statePtr->cctx, (const void *) key, key_len, cipher, NULL);
    }
    if (!res) {
	Tcl_AppendResult(interp, "Initialize digest failed: ", REASON(), NULL);
	return TCL_ERROR;
    }
    return TCL_OK;
}

 *
 * Side effects:
 *	Adds buf to hash function
 *
 *-------------------------------------------------------------------
 */
int Tls_DigestUpdate(DigestState *statePtr, char *buf, size_t read) {
    int res = 0;

    if (statePtr->format & TYPE_MD) {
	res = EVP_DigestUpdate(statePtr->ctx, buf, read);
    } else if (statePtr->format & TYPE_HMAC) {
	res = HMAC_Update(statePtr->hctx, buf, read);
    } else if (statePtr->format & TYPE_CMAC) {
	res = CMAC_Update(statePtr->cctx, buf, read);
    }
    return res;
}

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

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

int Tls_DigestFinialize(Tcl_Interp *interp, DigestState *statePtr) {
    unsigned char md_buf[EVP_MAX_MD_SIZE];
    unsigned int md_len;
    int res = 0;

    /* Finalize hash function and calculate message digest */
    if (statePtr->format & TYPE_MD) {
	res = EVP_DigestFinal_ex(statePtr->ctx, md_buf, &md_len);
    } else if (statePtr->format & TYPE_HMAC) {
	res = HMAC_Final(statePtr->hctx, md_buf, &md_len);
    } else if (statePtr->format & TYPE_CMAC) {
	size_t len;
	res = CMAC_Final(statePtr->cctx, md_buf, &len);
	md_len = (unsigned int) len;
    }
    if (!res) {
	Tcl_AppendResult(interp, "Finalize digest failed: ", REASON(), NULL);
	return TCL_ERROR;
    }

    /* Return message digest as either a binary or hex string */
    if (statePtr->format & BIN_FORMAT) {
	Tcl_SetObjResult(interp, Tcl_NewByteArrayObj(md_buf, md_len));

    } else {
	Tcl_Obj *resultObj = Tcl_NewObj();
	unsigned char *ptr = Tcl_SetByteArrayLength(resultObj, md_len*2);

	for (unsigned int i = 0; i < md_len; i++) {
	    *ptr++ = hex[(md_buf[i] >> 4) & 0x0F];
	    *ptr++ = hex[md_buf[i] & 0x0F];
	}
	Tcl_SetObjResult(interp, resultObj);
    }
    return TCL_OK;
}

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


/*
 *-------------------------------------------------------------------
 *
 * Tls_DigestFile --
 *
 *	Return message digest for file using user specified hash function.
 *
 * Returns:
 *	TCL_OK or TCL_ERROR
 *
 * Side effects:
 *	Result is message digest or error message
 *
 *-------------------------------------------------------------------
 */
int Tls_DigestFile(Tcl_Interp *interp, Tcl_Obj *filename, const EVP_MD *md,
	const EVP_CIPHER *cipher, int format, Tcl_Obj *keyObj) {
    DigestState *statePtr;
    Tcl_Channel chan = NULL;
    unsigned char buf[BUFFER_SIZE];
    int res = TCL_OK, len;

    /* Open file channel */
    chan = Tcl_FSOpenFileChannel(interp, filename, "rb", 0444);

    /* Create state data struct */
    if ((statePtr = Tls_DigestNew(interp, format)) == NULL) {
	res = TCL_ERROR;
	goto done;
    }

    /* Initialize hash function */
    if ((res = Tls_DigestInit(interp, statePtr, md, cipher, keyObj)) != TCL_OK) {
	goto done;
    }

    /* Read file data and update hash function */
    while (!Tcl_Eof(chan)) {
	len = Tcl_ReadRaw(chan, (char *) buf, BUFFER_SIZE);
	if (len > 0) {

 *	Read data from transform and write to buf
 *
 *----------------------------------------------------------------------
 */
int DigestInputProc(ClientData clientData, char *buf, int toRead, int *errorCodePtr) {
    DigestState *statePtr = (DigestState *) clientData;
    Tcl_Channel parent;
    int read, res = 0;
    *errorCodePtr = 0;

    /* Abort if nothing to process */
    if (toRead <= 0 || statePtr->self == (Tcl_Channel) NULL) {
	return 0;
    }

    } else if (!(statePtr->flags & CHAN_EOF)) {
	/* EOF */
	unsigned char md_buf[EVP_MAX_MD_SIZE];
	unsigned int md_len = 0;

	/* Finalize hash function and calculate message digest */
	if (statePtr->format & TYPE_MD) {
	    res = EVP_DigestFinal_ex(statePtr->ctx, md_buf, &md_len);
	} else if (statePtr->format & TYPE_HMAC) {
	    res = HMAC_Final(statePtr->hctx, md_buf, &md_len);
	} else if (statePtr->format & TYPE_CMAC) {
	    size_t len;
	    res = CMAC_Final(statePtr->cctx, md_buf, &len);
	    md_len = (unsigned int) len;
	}
	if (!res) {
	    Tcl_SetChannelError(statePtr->self, Tcl_ObjPrintf("Digest finalize failed: %s", REASON()));
	    *errorCodePtr = EINVAL;

	/* Write message digest to output channel as byte array or hex string */
	} else if (md_len > 0) {
	    if ((statePtr->format & BIN_FORMAT) && toRead >= (int) md_len) {
		read = md_len;
		memcpy(buf, md_buf, read);

	    } else if((statePtr->format & HEX_FORMAT) && toRead >= (int) (md_len*2)) {
		unsigned char hex_buf[EVP_MAX_MD_SIZE*2];
		unsigned char *ptr = hex_buf;

		for (unsigned int i = 0; i < md_len; i++) {
		    *ptr++ = hex[(md_buf[i] >> 4) & 0x0F];
		    *ptr++ = hex[md_buf[i] & 0x0F];
		}

 *
 * Side effects:
 *	Adds transform to channel and sets result to channel id or error message.
 *
 *----------------------------------------------------------------------
 */
static int
Tls_DigestChannel(Tcl_Interp *interp, const char *channel, const EVP_MD *md,
	const EVP_CIPHER *cipher, int format, Tcl_Obj *keyObj) {
    int mode; /* OR-ed combination of TCL_READABLE and TCL_WRITABLE */
    Tcl_Channel chan;
    DigestState *statePtr;

    /* Validate args */
    if (channel == (const char *) NULL) {
	return TCL_ERROR;
    }

    /* Get channel Id */
    chan = Tcl_GetChannel(interp, channel, &mode);
    if (chan == (Tcl_Channel) NULL) {
	return TCL_ERROR;

	Tcl_AppendResult(interp, "Initialize digest error: memory allocation failure", (char *) NULL);
	return TCL_ERROR;
    }
    statePtr->self = chan;
    statePtr->mode = mode;

    /* Initialize hash function */
    if (Tls_DigestInit(interp, statePtr, md, cipher, keyObj) != TCL_OK) {
	return TCL_ERROR;
    }

    /* Configure channel */
    Tcl_SetChannelOption(interp, chan, "-translation", "binary");
    if (Tcl_GetChannelBufferSize(chan) < EVP_MAX_MD_SIZE * 2) {
	Tcl_SetChannelBufferSize(chan, EVP_MAX_MD_SIZE * 2);

 *	TCL_OK or TCL_ERROR
 *
 * Side effects:
 *	Creates command or error message
 *
 *-------------------------------------------------------------------
 */
int Tls_DigestInstance(Tcl_Interp *interp, Tcl_Obj *cmdObj, const EVP_MD *md,
	const EVP_CIPHER *cipher, int format, Tcl_Obj *keyObj) {
    DigestState *statePtr;
    char *cmdName = Tcl_GetStringFromObj(cmdObj, NULL);

    /* Create state data struct */
    if ((statePtr = Tls_DigestNew(interp, format)) == NULL) {
	Tcl_AppendResult(interp, "Initialize digest error: memory allocation failure", (char *) NULL);
	return TCL_ERROR;
    }

    /* Initialize hash function */
    if (Tls_DigestInit(interp, statePtr, md, cipher, keyObj) != TCL_OK) {
	return TCL_ERROR;
    }

    /* Create instance command */
    statePtr->token = Tcl_CreateObjCommand(interp, cmdName, InstanceObjCmd,
	(ClientData) statePtr, InstanceDelCallback);

 * Side effects:
 *	Sets result to message digest or error message
 *
 *-------------------------------------------------------------------
 */
int
Tls_DigestData(Tcl_Interp *interp, int objc, Tcl_Obj *const objv[],
	const EVP_MD *md, const EVP_CIPHER *cipher, int format, Tcl_Obj *keyObj) {
    char *data;
    int len, res;
    unsigned int md_len;
    unsigned char md_buf[EVP_MAX_MD_SIZE];

    /* Validate arg count */
    if (objc != 2) {

	hmac = HMAC(md, (const void *) key, key_len, (const unsigned char *) data,
	    (size_t) len, md_buf, &md_len);
	res = (hmac != NULL);
    }

    /* Output digest to result per format (bin or hex) */
    if (res) {
	if (format & BIN_FORMAT) {
	    Tcl_SetObjResult(interp, Tcl_NewByteArrayObj(md_buf, md_len));

	} else {
	    Tcl_Obj *resultObj = Tcl_NewObj();
	    unsigned char *ptr = Tcl_SetByteArrayLength(resultObj, md_len*2);

	    for (unsigned int i = 0; i < md_len; i++) {

 * Side effects:
 *	Sets result to message digest or error message
 *
 *-------------------------------------------------------------------
 */
static int
DigestObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {
    int idx, len, format = HEX_FORMAT, res = TCL_OK, flags = 0;
    const char *digestname, *channel = NULL;
    Tcl_Obj *cmdObj = NULL, *dataObj = NULL, *fileObj = NULL, *keyObj = NULL;
    unsigned char *cipherName = NULL;
    const EVP_MD *md;
    const EVP_CIPHER *cipher;

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

    /* Validate arg count */
    if (objc < 3 || objc > 9) {
	Tcl_WrongNumArgs(interp, 1, objv, "digest ?-bin|-hex? ?-cipher name? ?-key hmac_key? [-channel chan | -command cmdName | -file filename | ?-data? data]");
	return TCL_ERROR;
    }

    /* Get digest */
    digestname = Tcl_GetStringFromObj(objv[1], &len);
    if (digestname == NULL || (md = EVP_get_digestbyname(digestname)) == NULL) {
	Tcl_AppendResult(interp, "Invalid digest \"", digestname, "\"", NULL);
	return TCL_ERROR;
    }

    /* Optimal case for blob of data */
    if (objc == 3 && type == TYPE_MD) {
	return Tls_DigestData(interp, --objc, ++objv, md, NULL, HEX_FORMAT | TYPE_MD, NULL);
    }

    /* Get options */
    for (idx = 2; idx < objc-1; idx++) {
	char *opt = Tcl_GetStringFromObj(objv[idx], NULL);

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

	OPTFLAG("-bin", format, BIN_FORMAT);
	OPTFLAG("-binary", format, BIN_FORMAT);
	OPTFLAG("-hex", format, HEX_FORMAT);
	OPTFLAG("-hexadecimal", format, HEX_FORMAT);
	OPTSTR("-chan", channel);
	OPTSTR("-channel", channel);
	OPTSTR("-cipher", cipherName);
	OPTOBJ("-command", cmdObj);
	OPTOBJ("-data", dataObj);
	OPTOBJ("-file", fileObj);
	OPTOBJ("-filename", fileObj);
	OPTOBJ("-key", keyObj);

	OPTBAD("option", "-bin, -channel, -cipher, -command, -data, -file, -filename, -hex, or -key");
	return TCL_ERROR;
    }

    /* If no option for last arg, then its the data */
    if (idx < objc) {
	dataObj = objv[idx];
    }

    /* Get cipher */
    if (cipherName != NULL) {
	cipher = EVP_get_cipherbyname(cipherName);
	if (cipher == NULL) {
	    Tcl_AppendResult(interp, "Invalid cipher \"", cipherName, "\"", NULL);
	    return TCL_ERROR;
	}
    }

    /* Define operation to perform */
    if (cipher != NULL) {
	format |= TYPE_CMAC;
    } else if (keyObj != NULL) {
	format |= TYPE_HMAC;
    } else {
	format |= TYPE_MD;
    }

    /* Calc digest on file, stacked channel, using instance command, or data blob */
    if (fileObj != NULL) {
	res = Tls_DigestFile(interp, fileObj, md, cipher, format, keyObj);
    } else if (channel != NULL) {
	res = Tls_DigestChannel(interp, channel, md, cipher, format, keyObj);
    } else if (cmdObj != NULL) {
	res = Tls_DigestInstance(interp, cmdObj, md, cipher, format, keyObj);
    } else if (dataObj != NULL) {
	Tcl_Obj *objs[2];
	objs[0] = NULL;
	objs[1] = dataObj;
	res = Tls_DigestData(interp, 2, objs, md, cipher, format, keyObj);
    }
    return res;
}

int CMACObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {
    return DigestObjCmd(clientData, interp, objc, objv);
}

int HMACObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {
    return DigestObjCmd(clientData, interp, objc, objv);
}

/*
 *-------------------------------------------------------------------
 *
 * Message Digest Convenience Commands --
 *
 *	Convenience commands for message digests.
 *
 * Returns:
 *	TCL_OK or TCL_ERROR
 *
 * Side effects:
 *	Sets result to message digest or error message
 *
 *-------------------------------------------------------------------
 */
int DigestMD4Cmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {
    return Tls_DigestData(interp, objc, objv, EVP_md4(), NULL, HEX_FORMAT, NULL);
}

int DigestMD5Cmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {
    return Tls_DigestData(interp, objc, objv, EVP_md5(), NULL, HEX_FORMAT, NULL);
}

int DigestSHA1Cmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {
    return Tls_DigestData(interp, objc, objv, EVP_sha1(), NULL, HEX_FORMAT, NULL);
}

int DigestSHA256Cmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {
    return Tls_DigestData(interp, objc, objv, EVP_sha256(), NULL, HEX_FORMAT, NULL);
}

int DigestSHA512Cmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {
    return Tls_DigestData(interp, objc, objv, EVP_sha512(), NULL, HEX_FORMAT, NULL);
}

/*
 *-------------------------------------------------------------------
 *
 * Tls_DigestCommands --
 *
 *	Create digest commands
 *
 * Returns:
 *	TCL_OK or TCL_ERROR
 *
 * Side effects:
 *	Creates commands
 *
 *-------------------------------------------------------------------
 */
int Tls_DigestCommands(Tcl_Interp *interp) {
    Tcl_CreateObjCommand(interp, "tls::digest", DigestObjCmd, (ClientData) 0, (Tcl_CmdDeleteProc *) NULL);
    Tcl_CreateObjCommand(interp, "tls::cmac", CMACObjCmd, (ClientData) 0, (Tcl_CmdDeleteProc *) NULL);
    Tcl_CreateObjCommand(interp, "tls::hmac", HMACObjCmd, (ClientData) 0, (Tcl_CmdDeleteProc *) NULL);
    Tcl_CreateObjCommand(interp, "tls::md4", DigestMD4Cmd, (ClientData) 0, (Tcl_CmdDeleteProc *) NULL);
    Tcl_CreateObjCommand(interp, "tls::md5", DigestMD5Cmd, (ClientData) 0, (Tcl_CmdDeleteProc *) NULL);
    Tcl_CreateObjCommand(interp, "tls::sha1", DigestSHA1Cmd, (ClientData) 0, (Tcl_CmdDeleteProc *) NULL);
    Tcl_CreateObjCommand(interp, "tls::sha256", DigestSHA256Cmd, (ClientData) 0, (Tcl_CmdDeleteProc *) NULL);
    Tcl_CreateObjCommand(interp, "tls::sha512", DigestSHA512Cmd, (ClientData) 0, (Tcl_CmdDeleteProc *) NULL);
    Tcl_CreateObjCommand(interp, "tls::unstack", UnstackObjCmd, (ClientData) 0, (Tcl_CmdDeleteProc *) NULL);
    return TCL_OK;
}

 *-------------------------------------------------------------------
 */
static int CiphersObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {
    SSL_CTX *ctx = NULL;
    SSL *ssl = NULL;
    STACK_OF(SSL_CIPHER) *sk = NULL;
    int index, verbose = 0, use_supported = 0;
    int min_version, max_version;

    dprintf("Called");

#if OPENSSL_VERSION_NUMBER < 0x10100000L
    OpenSSL_add_all_ciphers(); /* Make sure they're loaded */
#endif