#include <openssl/safestack.h>

/* Min OpenSSL version */
#if OPENSSL_VERSION_NUMBER < 0x10101000L
#error "Only OpenSSL v1.1.1 or later is supported"
#endif

/*
 * External functions
 */

/*
 * Forward declarations
 */

#define F2N(key, dsp) \
	(((key) == NULL) ? (char *) NULL : \

 *
 *	Monitors SSL certificate validation process. Used to control the
 *	behavior when the SSL_VERIFY_PEER flag is set. This is called
 *	whenever a certificate is inspected or decided invalid. Called for
 *	each certificate in the cert chain.
 *
 * Checks:
 *	certificate chain is checked starting with the deepest nesting level
 *	The certificate chain is checked starting with the deepest nesting level
 *	  (the root CA certificate) and worked upward to the peer's certificate.
 *	All signatures are valid, current time is within first and last validity time.
 *	Check that the certificate is issued by the issuer certificate issuer.
 *	Check the revocation status for each certificate.
 *	Check the validity of the given CRL and the cert revocation status.
 *	Check the policies of all the certificates
 *

}

/*
 *-------------------------------------------------------------------
 *
 * Tls_Error --
 *
 *	Calls callback with list of errors.
 *	Calls callback with error message.
 *
 * Side effects:
 *	The err field of the currently operative State is set
 *	  to a string describing the SSL negotiation failure reason
 *
 *-------------------------------------------------------------------
 */

}

/*
 *-------------------------------------------------------------------
 *
 * Password Callback --
 *
 *	Called when a password for a private key loading/storing a PEM
 *	certificate with encryption. Evals callback script and returns
 *	the result as the password string in buf.
 *	Called when a password is needed for a private key when loading
 *	or storing a PEM certificate with encryption. Evals callback
 *	script and returns the result as the password string in buf.
 *
 * Results:
 *	None
 *
 * Side effects:
 *	Calls callback (if defined)
 *
 * Returns:
 *	Password size in bytes or -1 for an error.
 *
 *-------------------------------------------------------------------
 */
static int
PasswordCallback(char *buf, int size, int rwflag, void *udata) {
    State *statePtr	= (State *) udata;
    Tcl_Interp *interp	= statePtr->interp;
    Tcl_Obj *cmdPtr;
    int code;
    Tcl_Size len;

    dprintf("Called");

    /* If no callback, use default callback */
    if (statePtr->password == NULL) {
	if (Tcl_EvalEx(interp, "tls::password", -1, TCL_EVAL_GLOBAL) == TCL_OK) {
	    char *ret = (char *) Tcl_GetStringResult(interp);
	    strncpy(buf, ret, (size_t) size);
	    return (int)strlen(ret);
	    char *ret = (char *) Tcl_GetStringFromObj(Tcl_GetObjResult(interp), &len);
	    if (len > (Tcl_Size) size-1) {
		len = (Tcl_Size) size-1;
	    }
	    strncpy(buf, ret, (size_t) len);
	    buf[len] = '\0';
	    return (int) len;
	} else {
	    return -1;
	}
    }

    /* Create command to eval with fn, rwflag, and size args */
    cmdPtr = Tcl_DuplicateObj(statePtr->password);

    }
    Tcl_DecrRefCount(cmdPtr);

    Tcl_Release((ClientData) statePtr);

    /* If successful, pass back password string and truncate if too long */
    if (code == TCL_OK) {
	Tcl_Size len;
	char *ret = (char *) Tcl_GetStringFromObj(Tcl_GetObjResult(interp), &len);
	if (len > (Tcl_Size) size-1) {
	    len = (Tcl_Size) size-1;
	}
	strncpy(buf, ret, (size_t) len);
	buf[len] = '\0';
	Tcl_Release((ClientData) interp);

    Tcl_ListObjAppendElement(interp, cmdPtr,
	Tcl_NewLongObj((long) SSL_SESSION_get_ticket_lifetime_hint(session)));

    /* Eval callback command */
    Tcl_IncrRefCount(cmdPtr);
    EvalCallback(interp, statePtr, cmdPtr);
    Tcl_DecrRefCount(cmdPtr);

    /* Return 0 for now until session handling is complete */
    return 0;
}

/*
 *-------------------------------------------------------------------
 *
 * ALPN Callback for Servers and NPN Callback for Clients --

	    char *str = Tcl_GetStringFromObj(list[j], &len);
	    *p++ = (unsigned char) len;
	    memcpy(p, str, (size_t) len);
	    p += len;
	}

	/* SSL_set_alpn_protos makes a copy of the protocol-list */
	/* Note: This functions reverses the return value convention */
	/* Note: This function reverses the return value convention */
	if (SSL_set_alpn_protos(statePtr->ssl, protos, protos_len)) {
	    Tcl_AppendResult(interp, "Set ALPN protocols failed: ", GET_ERR_REASON(), (char *) NULL);
	    Tcl_SetErrorCode(interp, "TLS", "IMPORT", "ALPN", "FAILED", (char *) NULL);
	    Tls_Free((char *) statePtr);
	    ckfree(protos);
	    return TCL_ERROR;
	}

    }

    /* set some callbacks */
    SSL_CTX_set_default_passwd_cb(ctx, PasswordCallback);
    SSL_CTX_set_default_passwd_cb_userdata(ctx, (void *)statePtr);

    /* read a Diffie-Hellman parameters file, or use the built-in one */
    Tcl_DStringInit(&ds);
#ifdef OPENSSL_NO_DH
    if (DHparams != NULL) {
	Tcl_AppendResult(interp, "DH parameter support not available", (char *) NULL);
	SSL_CTX_free(ctx);
	return NULL;
    }
#else
    {
	DH* dh;
	if (DHparams != NULL) {
	    BIO *bio;

	    Tcl_DStringInit(&ds);
	    bio = BIO_new_file(F2N(DHparams, &ds), "r");
	    if (!bio) {
		Tcl_DStringFree(&ds);
		Tcl_AppendResult(interp, "Could not find DH parameters file", (char *) NULL);
		SSL_CTX_free(ctx);
		return NULL;
	    }

#endif

    /* set our certificate */
    load_private_key = 0;
    if (certfile != NULL) {
	load_private_key = 1;

	Tcl_DStringInit(&ds);
	if (SSL_CTX_use_certificate_file(ctx, F2N(certfile, &ds), SSL_FILETYPE_PEM) <= 0) {
	    Tcl_DStringFree(&ds);
	    Tcl_AppendResult(interp, "unable to set certificate file ", certfile, ": ",
		GET_ERR_REASON(), (char *) NULL);
	    SSL_CTX_free(ctx);
	    return NULL;
	}

	if (keyfile != NULL) {
	    /* get the private key associated with this certificate */
	    if (keyfile == NULL) {
		keyfile = certfile;
	    }

	    Tcl_DStringInit(&ds);
	    if (SSL_CTX_use_PrivateKey_file(ctx, F2N(keyfile, &ds), SSL_FILETYPE_PEM) <= 0) {
		Tcl_DStringFree(&ds);
		/* flush the passphrase which might be left in the result */
		Tcl_SetResult(interp, NULL, TCL_STATIC);
		Tcl_AppendResult(interp, "unable to set public key file ", keyfile, " ",
		    GET_ERR_REASON(), (char *) NULL);
		SSL_CTX_free(ctx);

    }

    /* Overrides for the CA verify path and file */
    {
#if OPENSSL_VERSION_NUMBER < 0x30000000L
	if (CApath != NULL || CAfile != NULL) {
	    Tcl_DString ds1;
	    Tcl_DStringInit(&ds);
	    Tcl_DStringInit(&ds1);

	    if (!SSL_CTX_load_verify_locations(ctx, F2N(CAfile, &ds), F2N(CApath, &ds1))) {
		abort++;
	    }
	    Tcl_DStringFree(&ds);
	    Tcl_DStringFree(&ds1);

	    /* Set list of CAs to send to client when requesting a client certificate */
	    /* https://sourceforge.net/p/tls/bugs/57/ */
	    /* XXX:TODO: Let the user supply values here instead of something that exists on the filesystem */
	    Tcl_DStringInit(&ds);
	    STACK_OF(X509_NAME) *certNames = SSL_load_client_CA_file(F2N(CAfile, &ds));
	    if (certNames != NULL) {
		SSL_CTX_set_client_CA_list(ctx, certNames);
	    }
	    Tcl_DStringFree(&ds);
	}

#else
	if (CApath != NULL) {
	    Tcl_DStringInit(&ds);
	    if (!SSL_CTX_load_verify_dir(ctx, F2N(CApath, &ds))) {
		abort++;
	    }
	    Tcl_DStringFree(&ds);
	}
	if (CAfile != NULL) {
	    Tcl_DStringInit(&ds);
	    if (!SSL_CTX_load_verify_file(ctx, F2N(CAfile, &ds))) {
		abort++;
	    }
	    Tcl_DStringFree(&ds);

	    /* Set list of CAs to send to client when requesting a client certificate */
	    Tcl_DStringInit(&ds);
	    STACK_OF(X509_NAME) *certNames = SSL_load_client_CA_file(F2N(CAfile, &ds));
	    if (certNames != NULL) {
		SSL_CTX_set_client_CA_list(ctx, certNames);
	    }
	    Tcl_DStringFree(&ds);
	}
#endif