<dt><strong>protocol</strong> <em>version</em></dt>
	<dd>The protocol version used for the connection:
	    SSL2, SSL3, TLS1, TLS1.1, TLS1.2, TLS1.3, or unknown.</dd>
	<dt><strong>sbits</strong> <em>n</em></dt>
	<dd>The number of bits used for the session key.</dd>
	<dt><strong>signatureHashAlgorithm</strong> <em>algorithm</em></dt>
	<dd>The signature hash algorithm.</dd>
	<dt><strong>signatureType</strong> <em>type</em></dt>
	<dd>The signature type value.</dd>
	<dt><strong>verifyDepth</strong> <em>n</em></dt>
	<dd>Maximum depth for the certificate chain verification.
	    Default is -1, to check all.</dd>
	<dt><strong>verifyMode</strong> <em>list</em></dt>
	<dd>List of certificate verification modes.</dd>
	<dt><strong>verifyResult</strong> <em>result</em></dt>
	<dd>Certificate verification result.</dd>
	<dt><strong>ca_names</strong> <em>list</em></dt>
	<dd>List of the Certificate Authorities used to create the certificate.</dd>
    </dl>
</blockquote>
<blockquote>
	<b>Certificate Status</b>

 * Side effects:
 *	Evaluates callback command
 *
 *-------------------------------------------------------------------
 */
static int
EvalCallback(Tcl_Interp *interp, State *statePtr, Tcl_Obj *cmdPtr) {
    int code, ok = 0;

    Tcl_Preserve((ClientData) interp);
    Tcl_Preserve((ClientData) statePtr);

    /* Eval callback with success for ok or return value 1, fail for error or return value 0 */
    Tcl_ResetResult(interp);
    code = Tcl_EvalObjEx(interp, cmdPtr, TCL_EVAL_GLOBAL);
    if (code == TCL_OK) {
	/* Check result for return value */
	Tcl_Obj *result = Tcl_GetObjResult(interp);
	if (result == NULL || Tcl_GetIntFromObj(interp, result, &ok) != TCL_OK) {
	    ok = 1;
	}
    } else {
	/* Error - reject the certificate */

#if (TCL_MAJOR_VERSION == 8) && (TCL_MINOR_VERSION < 6)
	Tcl_BackgroundError(interp);
#else
	Tcl_BackgroundException(interp, code);
#endif
    }

    if (statePtr->vcmd == (Tcl_Obj*)NULL) {
	if (statePtr->vflags & SSL_VERIFY_FAIL_IF_NO_PEER_CERT) {
	    return ok;
	} else {
	    return 1;
	}
    } else if (cert == NULL || ssl == NULL) {
	return 0;
    }

    /* Create command to eval */
    cmdPtr = Tcl_DuplicateObj(statePtr->vcmd);
    Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewStringObj("verify", -1));
    Tcl_ListObjAppendElement(interp, cmdPtr,
	Tcl_NewStringObj(Tcl_GetChannelName(statePtr->self), -1));

    const unsigned char *p;
    size_t len, remaining;

    dprintf("Called");

    if (statePtr->vcmd == (Tcl_Obj*)NULL) {
	return SSL_CLIENT_HELLO_SUCCESS;
    } else if (ssl == (const SSL *)NULL || arg == (void *)NULL) {
	return SSL_CLIENT_HELLO_ERROR;
    }

    /* Get names */
    if (!SSL_client_hello_get0_ext(ssl, TLSEXT_TYPE_server_name, &p, &remaining) || remaining <= 2) {
	*alert = SSL_R_SSLV3_ALERT_ILLEGAL_PARAMETER;
	return SSL_CLIENT_HELLO_ERROR;

CiphersObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {
    Tcl_Obj *objPtr = NULL;
    SSL_CTX *ctx = NULL;
    SSL *ssl = NULL;
    STACK_OF(SSL_CIPHER) *sk;
    char *cp, buf[BUFSIZ];
    int index, verbose = 0, use_supported = 0;
    const SSL_METHOD *method;

    dprintf("Called");

    if ((objc < 2) || (objc > 4)) {
	Tcl_WrongNumArgs(interp, 1, objv, "protocol ?verbose? ?supported?");
	return TCL_ERROR;
    }

    switch ((enum protocol)index) {
	case TLS_SSL2:
#if OPENSSL_VERSION_NUMBER >= 0x10100000L || defined(NO_SSL2) || defined(OPENSSL_NO_SSL2)
	    Tcl_AppendResult(interp, protocols[index], ": protocol not supported", NULL);
	    return TCL_ERROR;
#else
	    method = SSLv2_method(); break;
#endif
	case TLS_SSL3:
#if defined(NO_SSL3) || defined(OPENSSL_NO_SSL3) || defined(OPENSSL_NO_SSL3_METHOD)
	    Tcl_AppendResult(interp, protocols[index], ": protocol not supported", NULL);
	    return TCL_ERROR;
#else
	    method = SSLv3_method(); break;
#endif
	case TLS_TLS1:
#if defined(NO_TLS1) || defined(OPENSSL_NO_TLS1) || defined(OPENSSL_NO_TLS1_METHOD)
	    Tcl_AppendResult(interp, protocols[index], ": protocol not supported", NULL);
	    return TCL_ERROR;
#else
	    method = TLSv1_method(); break;
#endif
	case TLS_TLS1_1:
#if defined(NO_TLS1_1) || defined(OPENSSL_NO_TLS1_1) || defined(OPENSSL_NO_TLS1_1_METHOD)
	    Tcl_AppendResult(interp, protocols[index], ": protocol not supported", NULL);
	    return TCL_ERROR;
#else
	    method = TLSv1_1_method(); break;
#endif
	case TLS_TLS1_2:
#if defined(NO_TLS1_2) || defined(OPENSSL_NO_TLS1_2) || defined(OPENSSL_NO_TLS1_2_METHOD)
	    Tcl_AppendResult(interp, protocols[index], ": protocol not supported", NULL);
	    return TCL_ERROR;
#else
	    method = TLSv1_2_method(); break;
#endif
	case TLS_TLS1_3:
#if defined(NO_TLS1_3) || defined(OPENSSL_NO_TLS1_3)
	    Tcl_AppendResult(interp, protocols[index], ": protocol not supported", NULL);
	    return TCL_ERROR;
#else
	    method = TLS_method();
	    SSL_CTX_set_min_proto_version(ctx, TLS1_3_VERSION);
	    SSL_CTX_set_max_proto_version(ctx, TLS1_3_VERSION);
	    break;
#endif
	default:
	    method = TLS_method();
	    break;
    }

    ctx = SSL_CTX_new(method);
    if (ctx == NULL) {
	Tcl_AppendResult(interp, REASON(), NULL);
	return TCL_ERROR;
    }

    ssl = SSL_new(ctx);
    if (ssl == NULL) {

    /* Get certificate for peer or self */
    if (objc == 2) {
	peer = SSL_get_peer_certificate(statePtr->ssl);
    } else {
	peer = SSL_get_certificate(statePtr->ssl);
    }
    /* Get X509 certificate info */
    if (peer) {
	objPtr = Tls_NewX509Obj(interp, peer);
	if (objc == 2) {
	    X509_free(peer);
	    peer = NULL;
	}
    } else {
	objPtr = Tcl_NewListObj(0, NULL);
    }

    /* Peer cert chain (client only) */
    STACK_OF(X509)* ssl_certs = SSL_get_peer_cert_chain(statePtr->ssl);
    if (ssl_certs == NULL || sk_X509_num(ssl_certs) == 0) {
	Tcl_SetErrorCode(interp, "TLS", "STATUS", "CERTIFICATE", (char *) NULL);
	Tcl_IncrRefCount(objPtr);
	Tcl_DecrRefCount(objPtr);
	return TCL_ERROR;
    }

    /* Peer name */
    Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("peername", -1));
    Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj(SSL_get0_peername(statePtr->ssl), -1));

    Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("sbits", -1));
    Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewIntObj(SSL_get_cipher_bits(statePtr->ssl, NULL)));

    ciphers = (char*)SSL_get_cipher(statePtr->ssl);
    if ((ciphers != NULL) && (strcmp(ciphers, "(NONE)") != 0)) {
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("cipher", -1));
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj(ciphers, -1));
    }

    /* Verify the X509 certificate presented by the peer */
    Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("verifyResult", -1));
    Tcl_ListObjAppendElement(interp, objPtr,
	Tcl_NewStringObj(X509_verify_cert_error_string(SSL_get_verify_result(statePtr->ssl)), -1));

    /* Verify mode */
    Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("verifyMode", -1));
    /* SSL_CTX_get_verify_mode(ctx) */
    mode = SSL_get_verify_mode(statePtr->ssl);
    if (mode && SSL_VERIFY_NONE) {
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("none", -1));
    } else {
	Tcl_Obj *listObjPtr = Tcl_NewListObj(0, NULL);
	if (mode && SSL_VERIFY_PEER) {
	    Tcl_ListObjAppendElement(interp, listObjPtr, Tcl_NewStringObj("peer", -1));
	}
	if (mode && SSL_VERIFY_FAIL_IF_NO_PEER_CERT) {
	    Tcl_ListObjAppendElement(interp, listObjPtr, Tcl_NewStringObj("fail if no peer cert", -1));
	}
	if (mode && SSL_VERIFY_CLIENT_ONCE) {
	    Tcl_ListObjAppendElement(interp, listObjPtr, Tcl_NewStringObj("client once", -1));
	}
	if (mode && SSL_VERIFY_POST_HANDSHAKE) {
	    Tcl_ListObjAppendElement(interp, listObjPtr, Tcl_NewStringObj("post handshake", -1));
	}
	Tcl_ListObjAppendElement(interp, objPtr, listObjPtr);
    }

    /* Verify mode depth */
    Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("verifyDepth", -1));
    /* SSL_CTX_get_verify_depth(ctx) */
    Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewIntObj(SSL_get_verify_depth(statePtr->ssl)));

    /* Report the selected protocol as a result of the negotiation */
    SSL_get0_alpn_selected(statePtr->ssl, &proto, &len);
    Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("alpn", -1));
    Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj((char *)proto, (int) len));
    Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("protocol", -1));
    Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj(SSL_get_version(statePtr->ssl), -1));

    /* Valid for non-RSA signature and TLS 1.3 */
    Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("signatureHashAlgorithm", -1));
    if (objc == 2 ? SSL_get_peer_signature_nid(statePtr->ssl, &nid) : SSL_get_signature_nid(statePtr->ssl, &nid)) {
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj(OBJ_nid2ln(nid), -1));
    } else {
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("", -1));
    }
    Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("signatureType", -1));
    if (objc == 2 ? SSL_get_peer_signature_type_nid(statePtr->ssl, &nid) : SSL_get_signature_type_nid(statePtr->ssl, &nid)) {
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj(OBJ_nid2ln(nid), -1));
    } else {
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("", -1));
    }

    Tcl_SetObjResult(interp, objPtr);

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

static int ConnectionInfoObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {
    Tcl_Channel chan;		/* The channel to set a mode on. */
    State *statePtr;		/* client state for ssl socket */
    Tcl_Obj *objPtr, *listPtr;
    const SSL *ssl;
    const SSL_CIPHER *cipher;
    const SSL_SESSION *session;

    long mode;

    if (objc != 2) {
	Tcl_WrongNumArgs(interp, 1, objv, "channel");
	return(TCL_ERROR);
    }

	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("cipher", -1));
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj(SSL_CIPHER_get_name(cipher), -1));
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("standard_name", -1));
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj(SSL_CIPHER_standard_name(cipher), -1));

	bits = SSL_CIPHER_get_bits(cipher, &alg_bits);
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("secret_bits", -1));
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewIntObj(bits));
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("algorithm_bits", -1));
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewIntObj(alg_bits));
	/* alg_bits is actual key secret bits. If use bits and secret (algorithm) bits differ,
	   the rest of the bits are fixed, i.e. for limited export ciphers (bits < 56) */
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("min_version", -1));
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj(SSL_CIPHER_get_version(cipher), -1));

	/* Get OpenSSL-specific ID, not IANA ID */

    /* Session info */
    session = SSL_get_session(ssl);
    if (session != NULL) {
	const unsigned char *ticket;
	size_t len2;
	unsigned int ulen;
	const unsigned char *session_id, *proto;
	char buffer[SSL_MAX_MASTER_KEY_LENGTH];

	/* Report the selected protocol as a result of the ALPN negotiation */
	SSL_SESSION_get0_alpn_selected(session, &proto, &len2);
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("alpn", -1));
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj((char *)proto, (int) len2));

	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("timeout", -1));
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewLongObj(SSL_SESSION_get_timeout(session)));

	/* Session ticket lifetime hint (in seconds) */
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("lifetime", -1));
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewLongObj(SSL_SESSION_get_ticket_lifetime_hint(session)));

	/* Session id - TLSv1.2 and below only */
	session_id = SSL_SESSION_get_id(session, &ulen);
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("session_id", -1));
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewByteArrayObj(session_id, (int) ulen));

	/* Session context */
	session_id = SSL_SESSION_get0_id_context(session, &ulen);
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("session_context", -1));
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewByteArrayObj(session_id, (int) ulen));

	/* Session ticket - client only */
	SSL_SESSION_get0_ticket(session, &ticket, &len2);
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("session_ticket", -1));
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewByteArrayObj(ticket, (int) len2));

	/* Ticket app data */
	SSL_SESSION_get0_ticket_appdata(session, &ticket, &len2);

	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("NONE", -1));
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("expansion", -1));
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("NONE", -1));
#endif
    }

    /* Server info */
    {
	mode = SSL_CTX_get_session_cache_mode(statePtr->ctx);
	char *msg;
	
	if (mode & SSL_SESS_CACHE_OFF) {
	    msg = "off";
	} else if (mode & SSL_SESS_CACHE_CLIENT) {
	    msg = "client";
	} else if (mode & SSL_SESS_CACHE_SERVER) {
	    msg = "server";
	} else if (mode & SSL_SESS_CACHE_BOTH) {
	    msg = "both";
	} else {
	    msg = "unknown";
	}
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("session_cache_mode", -1));
	Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj(msg, -1));
    }

    /* CA List */
    /* IF not a server, same as SSL_get0_peer_CA_list. If server same as SSL_CTX_get_client_CA_list */
    listPtr = Tcl_NewListObj(0, NULL);
    STACK_OF(X509_NAME) *ca_list;
    if ((ca_list = SSL_get_client_CA_list(ssl)) != NULL) {
	char buffer[BUFSIZ];
	for (int i = 0; i < sk_X509_NAME_num(ca_list); i++) {
	    X509_NAME *name = sk_X509_NAME_value(ca_list, i);
	    if (name) {
		X509_NAME_oneline(name, buffer, BUFSIZ);
		Tcl_ListObjAppendElement(interp, listPtr, Tcl_NewStringObj(buffer, -1));
	    }
	}
    }
    Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("caList", -1));
    Tcl_ListObjAppendElement(interp, objPtr, listPtr);

    Tcl_SetObjResult(interp, objPtr);
    return TCL_OK;
	clientData = clientData;
}

/*

	    dprintf("Asked to wait for a TLS handshake that has already failed.  Returning soft error");
	    *errorCodePtr = ECONNRESET;
	}
	return(-1);
    }

    for (;;) {
	/* Not initialized yet! Also calls SSL_do_handshake. */
	if (statePtr->flags & TLS_TCL_SERVER) {
	    dprintf("Calling SSL_accept()");
	    err = SSL_accept(statePtr->ssl);

	} else {
	    dprintf("Calling SSL_connect()");
	    err = SSL_connect(statePtr->ssl);

#include <openssl/bio.h>
#include <openssl/sha.h>
#include <openssl/x509.h>
#include <openssl/x509v3.h>
#include <openssl/asn1.h>
#include "tlsInt.h"







/* Define maximum certificate size. Max PEM size 100kB and DER size is 24kB. */



#define CERT_STR_SIZE 32768



















/* Common macros */
#define LAPPEND_STR(interp, obj, text, value, size) {\
    if (text != NULL) Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj(text, -1)); \
    Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj(value, size)); \

}
#define LAPPEND_INT(interp, obj, text, value) {\
    if (text != NULL) Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj(text, -1)); \
    Tcl_ListObjAppendElement(interp, obj, Tcl_NewIntObj(value)); \
}
#define LAPPEND_LONG(interp, obj, text, value) {\
    if (text != NULL) Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj(text, -1)); \
    Tcl_ListObjAppendElement(interp, obj, Tcl_NewLongObj(value)); \

}
#define LAPPEND_BOOL(interp, obj, text, value) {\
    if (text != NULL) Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj(text, -1)); \
    Tcl_ListObjAppendElement(interp, obj, Tcl_NewBooleanObj(value)); \






}




#define LAPPEND_LIST(interp, obj, text, listObj) {\
    if (text != NULL) Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj(text, -1)); \
    Tcl_ListObjAppendElement(interp, obj, listObj); \
}

/*
 * Binary string to hex string
 */
int String_to_Hex(char* input, int len, char *output, int size) {
    int count = 0;

    for (int i = 0; i < len && count < size - 1; i++, count += 2) {
	sprintf(output + count, "%02X", input[i] & 0xff);
    }
    output[count] = 0;
    return count;
}

/*
 * BIO to Buffer
 */
int BIO_to_Buffer(int result, BIO *bio, void *buffer, int size) {
    int len = 0;
    int pending = BIO_pending(bio);

    if (result) {
	len = BIO_read(bio, buffer, (pending < size) ? pending : size);
	(void)BIO_flush(bio);
	if (len < 0) {
	    len = 0;
	}
    }
    return len;
}

/*
 *------------------------------------------------------*
 *
 *	Tls_NewX509Obj --
 *
 *	------------------------------------------------*
 *	Converts a X509 certificate into a Tcl_Obj
 *	------------------------------------------------*
 *
 *	Side effects:
 *		None
 *
 *	Result:
 *		A Tcl List Object representing the provided
 *		X509 certificate.
 *
 *------------------------------------------------------*
 */



Tcl_Obj*
Tls_NewX509Obj(Tcl_Interp *interp, X509 *cert) {
    Tcl_Obj *certPtr = Tcl_NewListObj(0, NULL), *listPtr;
    BIO *bio = BIO_new(BIO_s_mem());
    int mdnid, pknid, bits, len;
    uint32_t xflags, usage;





    char buffer[BUFSIZ];


    unsigned char md[EVP_MAX_MD_SIZE];



    STACK_OF(GENERAL_NAME) *names;
    STACK_OF(OPENSSL_STRING) *ocsp;






    unsigned long flags = XN_FLAG_RFC2253 | ASN1_STRFLGS_UTF8_CONVERT;
    flags &= ~ASN1_STRFLGS_ESC_MSB;



    if (bio == NULL || certPtr == NULL) {
	return NULL;
    }


    /* Signature algorithm and value - RFC 5280 section 4.1.1.2 and 4.1.1.3 */
    /* signatureAlgorithm is the id of the cryptographic algorithm used by the
	CA to sign this cert. signatureValue is the digital signature computed
	upon the ASN.1 DER encoded tbsCertificate. */
    {
	const X509_ALGOR *sig_alg;



	const ASN1_BIT_STRING *sig;
	int sig_nid;

	X509_get0_signature(&sig, &sig_alg, cert);

	/* sig_nid = X509_get_signature_nid(cert) */
	sig_nid = OBJ_obj2nid(sig_alg->algorithm);

	LAPPEND_STR(interp, certPtr, "signatureAlgorithm", OBJ_nid2ln(sig_nid), -1);
	len = (sig_nid != NID_undef) ? String_to_Hex(sig->data, sig->length, buffer, BUFSIZ) : 0;
	LAPPEND_STR(interp, certPtr, "signatureValue", buffer, len);
    }

    /* Version of the encoded certificate - RFC 5280 section 4.1.2.1 */
    LAPPEND_LONG(interp, certPtr, "version", X509_get_version(cert)+1);








    /* Unique number assigned by CA to certificate - RFC 5280 section 4.1.2.2 */
    len = BIO_to_Buffer(i2a_ASN1_INTEGER(bio, X509_get0_serialNumber(cert)), bio, buffer, BUFSIZ);



    LAPPEND_STR(interp, certPtr, "serialNumber", buffer, len);




    /* Signature algorithm used by the CA to sign the certificate. Must match
	signatureAlgorithm. RFC 5280 section 4.1.2.3 */
    LAPPEND_STR(interp, certPtr, "signature", OBJ_nid2ln(X509_get_signature_nid(cert)), -1);

    /* Issuer identifies the entity that signed and issued the cert. RFC 5280 section 4.1.2.4 */

    len = BIO_to_Buffer(X509_NAME_print_ex(bio, X509_get_issuer_name(cert), 0, flags), bio, buffer, BUFSIZ);





    LAPPEND_STR(interp, certPtr, "issuer", buffer, len);


    /* Certificate validity period is the interval the CA warrants that it will

	maintain info on the status of the certificate. RFC 5280 section 4.1.2.5 */
    /* Get Validity - Not Before */
    len = BIO_to_Buffer(ASN1_TIME_print(bio, X509_get0_notBefore(cert)), bio, buffer, BUFSIZ);
    LAPPEND_STR(interp, certPtr, "notBefore", buffer, len);

    /* Get Validity - Not After */

    len = BIO_to_Buffer(ASN1_TIME_print(bio, X509_get0_notAfter(cert)), bio, buffer, BUFSIZ);
    LAPPEND_STR(interp, certPtr, "notAfter", buffer, len);

    /* Subject identifies the entity associated with the public key stored in
	the subject public key field. RFC 5280 section 4.1.2.6 */


    len = BIO_to_Buffer(X509_NAME_print_ex(bio, X509_get_subject_name(cert), 0, flags), bio, buffer, BUFSIZ);

    LAPPEND_STR(interp, certPtr, "subject", buffer, len);


    /* SHA1 Fingerprint of cert - DER representation */
    if (X509_digest(cert, EVP_sha1(), md, &len)) {
    len = String_to_Hex(md, len, buffer, BUFSIZ);

	LAPPEND_STR(interp, certPtr, "sha1_hash", buffer, len);
    }

    /* SHA256 Fingerprint of cert - DER representation */
    if (X509_digest(cert, EVP_sha256(), md, &len)) {
    len = String_to_Hex(md, len, buffer, BUFSIZ);


	LAPPEND_STR(interp, certPtr, "sha256_hash", buffer, len);


    }





    /* Subject Public Key Info specifies the public key and identifies the


	algorithm with which the key is used. RFC 5280 section 4.1.2.7 */











    if (X509_get_signature_info(cert, &mdnid, &pknid, &bits, &xflags)) {
	ASN1_BIT_STRING *key;
	unsigned int n;


	LAPPEND_STR(interp, certPtr, "signingDigest", OBJ_nid2ln(mdnid), -1);
	LAPPEND_STR(interp, certPtr, "publicKeyAlgorithm", OBJ_nid2ln(pknid), -1);


	LAPPEND_INT(interp, certPtr, "bits", bits); /* Effective security bits */




	key = X509_get0_pubkey_bitstr(cert);
	len = String_to_Hex(key->data, key->length, buffer, BUFSIZ);
	LAPPEND_STR(interp, certPtr, "publicKey", buffer, len);

	len = 0;
	if (X509_pubkey_digest(cert, EVP_get_digestbynid(pknid), md, &n)) {
	    len = String_to_Hex(md, (int)n, buffer, BUFSIZ);
	}
	LAPPEND_STR(interp, certPtr, "publicKeyHash", buffer, len);

	len = 0;
	if (X509_digest(cert, EVP_get_digestbynid(mdnid), md, &n)) {
	    len = String_to_Hex(md, (int)n, buffer, BUFSIZ);
	}
	LAPPEND_STR(interp, certPtr, "signatureHash", buffer, len);
    }

    /* Get extensions flags */
    xflags = X509_get_extension_flags(cert);
    LAPPEND_INT(interp, certPtr, "extFlags", xflags);

	/* Check if cert was issued by CA cert issuer or self signed */
    LAPPEND_BOOL(interp, certPtr, "selfIssued", xflags & EXFLAG_SI);
    LAPPEND_BOOL(interp, certPtr, "selfSigned", xflags & EXFLAG_SS);

    /* The Unique Ids are used to handle the possibility of reuse of subject
	and/or issuer names over time. RFC 5280 section 4.1.2.8 */
    {
	const ASN1_BIT_STRING *iuid, *suid;
        X509_get0_uids(cert, &iuid, &suid);

	Tcl_ListObjAppendElement(interp, certPtr, Tcl_NewStringObj("issuerUniqueId", -1));
	if (iuid != NULL) {
	    Tcl_ListObjAppendElement(interp, certPtr, Tcl_NewByteArrayObj((char *)iuid->data, iuid->length));
	} else {
	    Tcl_ListObjAppendElement(interp, certPtr, Tcl_NewStringObj("", -1));
	}

	Tcl_ListObjAppendElement(interp, certPtr, Tcl_NewStringObj("subjectUniqueId", -1));
	if (suid != NULL) {
	    Tcl_ListObjAppendElement(interp, certPtr, Tcl_NewByteArrayObj((char *)suid->data, suid->length));
	} else {
	    Tcl_ListObjAppendElement(interp, certPtr, Tcl_NewStringObj("", -1));
	}
    }

    /* X509 v3 Extensions - RFC 5280 section 4.1.2.9 */
    len = X509_get_ext_count(cert);
    listPtr = Tcl_NewListObj(0, NULL);
    if (len > 0) {
	const STACK_OF(X509_EXTENSION) *exts = X509_get0_extensions(cert);


	for (int i=0; i < len; i++) {
	    X509_EXTENSION *ex = sk_X509_EXTENSION_value(exts, i);
	    ASN1_OBJECT *obj = X509_EXTENSION_get_object(ex);

	    Tcl_ListObjAppendElement(interp, listPtr, Tcl_NewStringObj(OBJ_nid2ln(OBJ_obj2nid(obj)), -1));
	}
    }
    LAPPEND_INT(interp, certPtr, "extCount", len);
    LAPPEND_LIST(interp, certPtr, "extensions", listPtr);

    /* Authority Key Identifier (AKI) is the Subject Key Identifier (SKI) of
	its signer (the CA). RFC 5280 section 4.2.1.1, NID_authority_key_identifier */
    {
	ASN1_OCTET_STRING *astring = X509_get0_authority_key_id(cert);
	len = 0;
	if (astring != NULL) {
	    len = String_to_Hex((char *)ASN1_STRING_get0_data(astring),
		ASN1_STRING_length(astring), buffer, BUFSIZ);
	}
	LAPPEND_STR(interp, certPtr, "authorityKeyIdentifier", buffer, len);
    }

    /* Subject Key Identifier (SKI) is used to dentify certificates that contain
	a particular public key. RFC 5280 section 4.2.1.2, NID_subject_key_identifier */
    {
	ASN1_OCTET_STRING *astring = X509_get0_subject_key_id(cert);
	len = 0;
	if (astring != NULL) {
	    len = String_to_Hex((char *)ASN1_STRING_get0_data(astring),
		ASN1_STRING_length(astring), buffer, BUFSIZ);
	}
	LAPPEND_STR(interp, certPtr, "subjectKeyIdentifier", buffer, len);
    }



    /* Key usage extension defines the purpose (e.g., encipherment, signature, certificate
	signing) of the key contained in the certificate. RFC 5280 section 4.2.1.3, NID_key_usage */
    listPtr = Tcl_NewListObj(0, NULL);
    usage = X509_get_key_usage(cert);
    if ((xflags & EXFLAG_KUSAGE) && usage < 0xffffff) {
	if (usage & KU_DIGITAL_SIGNATURE) {
	    Tcl_ListObjAppendElement(interp, listPtr, Tcl_NewStringObj("Digital Signature", -1));
	}
	if (usage & KU_NON_REPUDIATION) {
	    Tcl_ListObjAppendElement(interp, listPtr, Tcl_NewStringObj("Non-Repudiation", -1));
	}
	if (usage & KU_KEY_ENCIPHERMENT) {


	    Tcl_ListObjAppendElement(interp, listPtr, Tcl_NewStringObj("Key Encipherment", -1));

	}
	if (usage & KU_DATA_ENCIPHERMENT) {

	    Tcl_ListObjAppendElement(interp, listPtr, Tcl_NewStringObj("Data Encipherment", -1));
	}
	if (usage & KU_KEY_AGREEMENT) {
	    Tcl_ListObjAppendElement(interp, listPtr, Tcl_NewStringObj("Key Agreement", -1));
	}
	if (usage & KU_KEY_CERT_SIGN) {
	    Tcl_ListObjAppendElement(interp, listPtr, Tcl_NewStringObj("Certificate Signing", -1));
	}

	if (usage & KU_CRL_SIGN) {
	    Tcl_ListObjAppendElement(interp, listPtr, Tcl_NewStringObj("CRL Signing", -1));
	}
	if (usage & KU_ENCIPHER_ONLY) {
	    Tcl_ListObjAppendElement(interp, listPtr, Tcl_NewStringObj("Encipher Only", -1));
	}
	if (usage & KU_DECIPHER_ONLY) {
	    Tcl_ListObjAppendElement(interp, listPtr, Tcl_NewStringObj("Decipher Only", -1));
	}
    }
    LAPPEND_LIST(interp, certPtr, "keyUsage", listPtr);

    /* Certificate Purpose */
    {
	char *purpose = NULL;

	if (X509_check_purpose(cert, X509_PURPOSE_SSL_CLIENT, 0) > 0) {
	    purpose = "SSL Client";
	} else if (X509_check_purpose(cert, X509_PURPOSE_SSL_SERVER, 0) > 0) {
	    purpose = "SSL Server";
	} else if (X509_check_purpose(cert, X509_PURPOSE_NS_SSL_SERVER, 0) > 0) {
	    purpose = "MSS SSL Server";
	} else if (X509_check_purpose(cert, X509_PURPOSE_SMIME_SIGN, 0) > 0) {
	    purpose = "SMIME Signing";
	} else if (X509_check_purpose(cert, X509_PURPOSE_SMIME_ENCRYPT, 0) > 0) {
	    purpose = "SMIME Encryption";
	} else if (X509_check_purpose(cert, X509_PURPOSE_CRL_SIGN, 0) > 0) {
	    purpose = "CRL Signing";
	} else if (X509_check_purpose(cert, X509_PURPOSE_ANY, 0) > 0) {
	    purpose = "Any";
	} else if (X509_check_purpose(cert, X509_PURPOSE_OCSP_HELPER, 0) > 0) {
	    purpose = "OCSP Helper";
	} else if (X509_check_purpose(cert, X509_PURPOSE_TIMESTAMP_SIGN, 0) > 0) {
	    purpose = "Timestamp Signing";
	} else {
	    purpose = "";
	}

	LAPPEND_STR(interp, certPtr, "purpose", purpose, -1);
    }

    /* Get purposes */
    listPtr = Tcl_NewListObj(0, NULL);
	for (int j = 0; j < X509_PURPOSE_get_count(); j++) {
	    X509_PURPOSE *ptmp = X509_PURPOSE_get0(j);
	    Tcl_Obj *tmpPtr = Tcl_NewListObj(0, NULL);

	    for (int i = 0; i < 2; i++) {
		int idret = X509_check_purpose(cert, X509_PURPOSE_get_id(ptmp), i);
		Tcl_ListObjAppendElement(interp, tmpPtr, Tcl_NewStringObj(i ? "CA" : "nonCA", -1));
		Tcl_ListObjAppendElement(interp, tmpPtr, Tcl_NewStringObj(idret == 1 ? "Yes" : "No", -1));
	    }
	LAPPEND_LIST(interp, listPtr, X509_PURPOSE_get0_name(ptmp), tmpPtr);
    }
    LAPPEND_LIST(interp, certPtr, "certificatePurpose", listPtr);

    /* Certificate Policies - indicates the issuing CA considers its issuerDomainPolicy
	equivalent to the subject CA's subjectDomainPolicy. RFC 5280 section 4.2.1.4, NID_certificate_policies */
    if (xflags & EXFLAG_INVALID_POLICY) {
	/* Reject cert */
    }

    /* Policy Mappings - RFC 5280 section 4.2.1.5, NID_policy_mappings */

    /* Subject Alternative Name (SAN) contains additional URLs, DNS names, or IP
	addresses bound to certificate. RFC 5280 section 4.2.1.6, NID_subject_alt_name */
    listPtr = Tcl_NewListObj(0, NULL);
    if (names = X509_get_ext_d2i(cert, NID_subject_alt_name, NULL, NULL)) {
	for (int i=0; i < sk_GENERAL_NAME_num(names); i++) {
	    const GENERAL_NAME *name = sk_GENERAL_NAME_value(names, i);

	    len = BIO_to_Buffer(name && GENERAL_NAME_print(bio, name), bio, buffer, BUFSIZ);
	    LAPPEND_STR(interp, listPtr, NULL, buffer, len);
	}
	sk_GENERAL_NAME_pop_free(names, GENERAL_NAME_free);
    }
    LAPPEND_LIST(interp, certPtr, "subjectAltName", listPtr);

    /* Issuer Alternative Name is used to associate Internet style identities
	with the certificate issuer. RFC 5280 section 4.2.1.7, NID_issuer_alt_name */
    listPtr = Tcl_NewListObj(0, NULL);
    if (names = X509_get_ext_d2i(cert, NID_issuer_alt_name, NULL, NULL)) {
	for (int i=0; i < sk_GENERAL_NAME_num(names); i++) {
	    const GENERAL_NAME *name = sk_GENERAL_NAME_value(names, i);

	    len = BIO_to_Buffer(name && GENERAL_NAME_print(bio, name), bio, buffer, BUFSIZ);
	    LAPPEND_STR(interp, listPtr, NULL, buffer, len);
	}
	sk_GENERAL_NAME_pop_free(names, GENERAL_NAME_free);
    }
    LAPPEND_LIST(interp, certPtr, "issuerAltName", listPtr);

    /* Subject Directory Attributes provides identification attributes (e.g., nationality)
	of the subject. RFC 5280 section 4.2.1.8 (subjectDirectoryAttributes) */

    /* Basic Constraints identifies whether the subject of the cert is a CA and
	the max depth of valid cert paths for this cert. RFC 5280 section 4.2.1.9, NID_basic_constraints */
    if (xflags & EXFLAG_BCONS) {
	LAPPEND_LONG(interp, certPtr, "pathLen", X509_get_pathlen(cert));
    }
    LAPPEND_BOOL(interp, certPtr, "basicConstraintsCA", xflags & EXFLAG_CA);
    LAPPEND_BOOL(interp, certPtr, "basicConstraintsCritical", xflags & EXFLAG_CRITICAL);

    /* Name Constraints is only used in CA certs to indicate the name space for
	all subject names in subsequent certificates in a certification path
	MUST be located. RFC 5280 section 4.2.1.10, NID_name_constraints */

    /* Policy Constraints is only used in CA certs to limit the length of a
	cert chain for that CA. RFC 5280 section 4.2.1.11, NID_policy_constraints */

    /* Extended Key Usage indicates the purposes the certified public key may be
	used, beyond the basic purposes. RFC 5280 section 4.2.1.12, NID_ext_key_usage */
    listPtr = Tcl_NewListObj(0, NULL);
    if (xflags & EXFLAG_XKUSAGE) {
	usage = X509_get_extended_key_usage(cert);

	if (usage & XKU_SSL_SERVER) {
	    Tcl_ListObjAppendElement(interp, listPtr, Tcl_NewStringObj("TLS Web Server Authentication", -1));
	}
	if (usage & XKU_SSL_CLIENT) {
	    Tcl_ListObjAppendElement(interp, listPtr, Tcl_NewStringObj("TLS Web Client Authentication", -1));
	}
	if (usage & XKU_SMIME) {
	    Tcl_ListObjAppendElement(interp, listPtr, Tcl_NewStringObj("E-mail Protection", -1));
	}
	if (usage & XKU_CODE_SIGN) {
	    Tcl_ListObjAppendElement(interp, listPtr, Tcl_NewStringObj("Code Signing", -1));
	}


	if (usage & XKU_SGC) {
	    Tcl_ListObjAppendElement(interp, listPtr, Tcl_NewStringObj("SGC", -1));
	}
	if (usage & XKU_OCSP_SIGN) {
	    Tcl_ListObjAppendElement(interp, listPtr, Tcl_NewStringObj("OCSP Signing", -1));
	}



	if (usage & XKU_TIMESTAMP) {
	    Tcl_ListObjAppendElement(interp, listPtr, Tcl_NewStringObj("Time Stamping", -1));
	}

	if (usage & XKU_DVCS ) {
	    Tcl_ListObjAppendElement(interp, listPtr, Tcl_NewStringObj("DVCS", -1));
	}
	if (usage & XKU_ANYEKU) {
	    Tcl_ListObjAppendElement(interp, listPtr, Tcl_NewStringObj("Any Extended Key Usage", -1));
	}
    }
    LAPPEND_LIST(interp, certPtr, "extendedKeyUsage", listPtr);

    /* CRL Distribution Points identifies where CRL information can be obtained.
	RFC 5280 section 4.2.1.13*/
    {
	STACK_OF(DIST_POINT) *crl;
	listPtr = Tcl_NewListObj(0, NULL);

	if (crl = X509_get_ext_d2i(cert, NID_crl_distribution_points, NULL, NULL)) {
	    Tcl_Obj *namesPtr = Tcl_NewListObj(0, NULL);

	    for (int i=0; i < sk_DIST_POINT_num(crl); i++) {
		DIST_POINT *dp = sk_DIST_POINT_value(crl, i);
		DIST_POINT_NAME *distpoint = dp->distpoint;

		if (distpoint->type == 0) {
		    /* fullname GENERALIZEDNAME */
		    for (int j = 0; j < sk_GENERAL_NAME_num(distpoint->name.fullname); j++) {
			GENERAL_NAME *gen = sk_GENERAL_NAME_value(distpoint->name.fullname, j);
			int type;
			ASN1_STRING *uri = GENERAL_NAME_get0_value(gen, &type);
			if (type == GEN_URI) {
			    Tcl_ListObjAppendElement(interp, listPtr,
				Tcl_NewStringObj((char*)ASN1_STRING_get0_data(uri), ASN1_STRING_length(uri)));
			}
		    }
		} else if (distpoint->type == 1) {
		    /* relativename X509NAME */
		    STACK_OF(X509_NAME_ENTRY) *sk_relname = distpoint->name.relativename;
		    for (int j = 0; j < sk_X509_NAME_ENTRY_num(sk_relname); j++) {
			X509_NAME_ENTRY *e = sk_X509_NAME_ENTRY_value(sk_relname, j);
			ASN1_STRING *d = X509_NAME_ENTRY_get_data(e);
			Tcl_ListObjAppendElement(interp, listPtr,
			    Tcl_NewStringObj((char*)ASN1_STRING_data(d), ASN1_STRING_length(d)));
		    }
		}
	    }
	    CRL_DIST_POINTS_free(crl);

	}
	LAPPEND_LIST(interp, certPtr, "crlDistributionPoints", listPtr);
    }

    /* Freshest CRL extension */
    if (xflags & EXFLAG_FRESHEST) {
    }

    /* Authority Information Access indicates how to access info and services
	for the certificate issuer. RFC 5280 section 4.2.2.1, NID_info_access */
    /* Get On-line Certificate Status Protocol (OSCP) URL */
    {
	STACK_OF(OPENSSL_STRING) *ocsp;
	listPtr = Tcl_NewListObj(0, NULL);

	if (ocsp = X509_get1_ocsp(cert)) {
	    for (int i = 0; i < sk_OPENSSL_STRING_num(ocsp); i++) {
		Tcl_ListObjAppendElement(interp, listPtr,
		    Tcl_NewStringObj(sk_OPENSSL_STRING_value(ocsp, i), -1));
	    }
	    X509_email_free(ocsp);
	    /* sk_OPENSSL_STRING_free(ocsp); */
	}
	LAPPEND_LIST(interp, certPtr, "ocsp", listPtr);
    }

    /* CA Issuers URL, caIssuers */
    {
	STACK_OF(ACCESS_DESCRIPTION) *ads;
	listPtr = Tcl_NewListObj(0, NULL);

	if (ads = X509_get_ext_d2i(cert, NID_info_access, NULL, NULL)) {

	    for (int i = 0; i < sk_ACCESS_DESCRIPTION_num(ads); i++) {
		ACCESS_DESCRIPTION *ad = sk_ACCESS_DESCRIPTION_value(ads, i);
		if (OBJ_obj2nid(ad->method) == NID_ad_ca_issuers && ad->location) {
		    if (ad->location->type == GEN_URI) {
			unsigned char *buf;

			len = ASN1_STRING_to_UTF8(&buf, ad->location->d.uniformResourceIdentifier);
			Tcl_ListObjAppendElement(interp, listPtr, Tcl_NewStringObj(buf, len));
			OPENSSL_free(buf);
			break;
		    }
		}
	    }
	    /* sk_ACCESS_DESCRIPTION_pop_free(ads, ACCESS_DESCRIPTION_free); */
	    AUTHORITY_INFO_ACCESS_free(ads);
	}
	LAPPEND_LIST(interp, certPtr, "caIssuers", listPtr);
    }

    /* Subject Information Access - RFC 5280 section 4.2.2.2, NID_sinfo_access */

    /* Certificate Alias. If uses a PKCS#12 structure, alias will reflect the
	friendlyName attribute (RFC 2985). */
    len = 0;
    LAPPEND_STR(interp, certPtr, "alias", X509_alias_get0(cert, &len), len);

    /* Certificate and dump all data */
    {
	char certStr[CERT_STR_SIZE];

	/* Get certificate */
	len = BIO_to_Buffer(PEM_write_bio_X509(bio, cert), bio, certStr, CERT_STR_SIZE);
	LAPPEND_STR(interp, certPtr, "certificate", certStr, len);

	/* Get all cert info */
	len = BIO_to_Buffer(X509_print_ex(bio, cert, flags, 0), bio, certStr, CERT_STR_SIZE);
	LAPPEND_STR(interp, certPtr, "all", certStr, len);
    }

    BIO_free(bio);
    return certPtr;
}