/** 
 * XMLSec library
 *
 * X509 support
 *
 *
 * This is free software; see Copyright file in the source
 * distribution for preciese wording.
 * 
 * Copyright (c) 2003 America Online, Inc.  All rights reserved.
 */
#include "globals.h"

#ifndef XMLSEC_NO_X509

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>

#include <cert.h>
#include <secerr.h>

#include <libxml/tree.h>

#include <xmlsec/xmlsec.h>
#include <xmlsec/xmltree.h>
#include <xmlsec/keys.h>
#include <xmlsec/keyinfo.h>
#include <xmlsec/keysmngr.h>
#include <xmlsec/base64.h>
#include <xmlsec/errors.h>

#include <xmlsec/nss/crypto.h>
#include <xmlsec/nss/x509.h>

/**************************************************************************
 *
 * Internal NSS X509 store CTX
 *
 *************************************************************************/
typedef struct _xmlSecNssX509StoreCtx		xmlSecNssX509StoreCtx, 
						*xmlSecNssX509StoreCtxPtr;
struct _xmlSecNssX509StoreCtx {
    CERTCertList* certsList; /* just keeping a reference to destroy later */
};	    

/****************************************************************************
 *
 * xmlSecNssKeyDataStoreX509Id:
 *
 * xmlSecNssX509StoreCtx is located after xmlSecTransform
 *
 ***************************************************************************/
#define xmlSecNssX509StoreGetCtx(store) \
    ((xmlSecNssX509StoreCtxPtr)(((xmlSecByte*)(store)) + \
				    sizeof(xmlSecKeyDataStoreKlass)))
#define xmlSecNssX509StoreSize	\
    (sizeof(xmlSecKeyDataStoreKlass) + sizeof(xmlSecNssX509StoreCtx))
 
static int		xmlSecNssX509StoreInitialize	(xmlSecKeyDataStorePtr store);
static void		xmlSecNssX509StoreFinalize	(xmlSecKeyDataStorePtr store);
static int 		xmlSecNssX509NameStringRead	(xmlSecByte **str, 
							 int *strLen, 
							 xmlSecByte *res, 
							 int resLen,
							 xmlSecByte delim, 
							 int ingoreTrailingSpaces);
static xmlSecByte * 	xmlSecNssX509NameRead		(xmlSecByte *str, 
							 int len);

static void 		xmlSecNssNumToItem(SECItem *it, unsigned long num);


static xmlSecKeyDataStoreKlass xmlSecNssX509StoreKlass = {
    sizeof(xmlSecKeyDataStoreKlass),
    xmlSecNssX509StoreSize,

    /* data */
    xmlSecNameX509Store,			/* const xmlChar* name; */ 
        
    /* constructors/destructor */
    xmlSecNssX509StoreInitialize,		/* xmlSecKeyDataStoreInitializeMethod initialize; */
    xmlSecNssX509StoreFinalize,			/* xmlSecKeyDataStoreFinalizeMethod finalize; */

    /* reserved for the future */
    NULL,					/* void* reserved0; */
    NULL,					/* void* reserved1; */
};

static CERTCertificate*		xmlSecNssX509FindCert(xmlChar *subjectName,
						      xmlChar *issuerName,
						      xmlChar *issuerSerial,
						      xmlChar *ski);


/** 
 * xmlSecNssX509StoreGetKlass:
 * 
 * The NSS X509 certificates key data store klass.
 *
 * Returns: pointer to NSS X509 certificates key data store klass.
 */
xmlSecKeyDataStoreId 
xmlSecNssX509StoreGetKlass(void) {
    return(&xmlSecNssX509StoreKlass);
}

/**
 * xmlSecNssX509StoreFindCert:
 * @store:		the pointer to X509 key data store klass.
 * @subjectName:	the desired certificate name.
 * @issuerName:		the desired certificate issuer name.
 * @issuerSerial:	the desired certificate issuer serial number.
 * @ski:		the desired certificate SKI.
 * @keyInfoCtx:		the pointer to <dsig:KeyInfo/> element processing context.
 *
 * Searches @store for a certificate that matches given criteria.
 *
 * Returns: pointer to found certificate or NULL if certificate is not found
 * or an error occurs.
 */
CERTCertificate *
xmlSecNssX509StoreFindCert(xmlSecKeyDataStorePtr store, xmlChar *subjectName,
				xmlChar *issuerName, xmlChar *issuerSerial,
				xmlChar *ski, xmlSecKeyInfoCtx* keyInfoCtx) {
    xmlSecNssX509StoreCtxPtr ctx;
    
    xmlSecAssert2(xmlSecKeyDataStoreCheckId(store, xmlSecNssX509StoreId), NULL);
    xmlSecAssert2(keyInfoCtx != NULL, NULL);

    ctx = xmlSecNssX509StoreGetCtx(store);
    xmlSecAssert2(ctx != NULL, NULL);

    return(xmlSecNssX509FindCert(subjectName, issuerName, issuerSerial, ski));
}

/**
 * xmlSecNssX509StoreVerify:
 * @store:		the pointer to X509 key data store klass.
 * @certs:		the untrusted certificates stack.
 * @keyInfoCtx:		the pointer to <dsig:KeyInfo/> element processing context.
 *
 * Verifies @certs list.
 *
 * Returns: pointer to the first verified certificate from @certs.
 */ 
CERTCertificate * 	
xmlSecNssX509StoreVerify(xmlSecKeyDataStorePtr store, CERTCertList* certs,
			     xmlSecKeyInfoCtx* keyInfoCtx) {
    xmlSecNssX509StoreCtxPtr ctx;
    CERTCertListNode*       head;
    CERTCertificate*       cert = NULL;
    CERTCertListNode*       head1;
    CERTCertificate*       cert1 = NULL;
    SECStatus status = SECFailure;
    int64 timeboundary;
    int64 tmp1, tmp2;

    xmlSecAssert2(xmlSecKeyDataStoreCheckId(store, xmlSecNssX509StoreId), NULL);
    xmlSecAssert2(certs != NULL, NULL);
    xmlSecAssert2(keyInfoCtx != NULL, NULL);

    ctx = xmlSecNssX509StoreGetCtx(store);
    xmlSecAssert2(ctx != NULL, NULL);

    for (head = CERT_LIST_HEAD(certs);
         !CERT_LIST_END(head, certs);
         head = CERT_LIST_NEXT(head)) {
        cert = head->cert;
	if(keyInfoCtx->certsVerificationTime > 0) {
	    /* convert the time since epoch in seconds to microseconds */
	    LL_UI2L(timeboundary, keyInfoCtx->certsVerificationTime);
	    tmp1 = (int64)PR_USEC_PER_SEC;
	    tmp2 = timeboundary;
	    LL_MUL(timeboundary, tmp1, tmp2);
	} else {
	    timeboundary = PR_Now();
	}

	/* if cert is the issuer of any other cert in the list, then it is 
	 * to be skipped */
	for (head1 = CERT_LIST_HEAD(certs); 
	     !CERT_LIST_END(head1, certs);
	     head1 = CERT_LIST_NEXT(head1)) {

	    cert1 = head1->cert;
	    if (cert1 == cert) {
		continue;
	    }

	    if (SECITEM_CompareItem(&cert1->derIssuer, &cert->derSubject)
	                              == SECEqual) {
		break;
	    }
	}

	if (!CERT_LIST_END(head1, certs)) {
	    continue;
	}

	status = CERT_VerifyCertificate(CERT_GetDefaultCertDB(), 
					cert, PR_FALSE, 
					(SECCertificateUsage)0,
                			timeboundary , NULL, NULL, NULL);
	if (status == SECSuccess) {
	    break;
	}
    }

    if (status == SECSuccess) {
	return (cert);
    }
    
    switch(PORT_GetError()) {
	case SEC_ERROR_EXPIRED_ISSUER_CERTIFICATE:
	case SEC_ERROR_CA_CERT_INVALID:
	case SEC_ERROR_UNKNOWN_SIGNER:
            xmlSecError(XMLSEC_ERRORS_HERE,
                        xmlSecErrorsSafeString(xmlSecKeyDataStoreGetName(store)),
                        NULL,
                        XMLSEC_ERRORS_R_CERT_ISSUER_FAILED,
                        "cert with subject name %s could not be verified because the issuer's cert is expired/invalid or not found",
                        cert->subjectName);
	    break;
	case SEC_ERROR_EXPIRED_CERTIFICATE:
            xmlSecError(XMLSEC_ERRORS_HERE,
                        xmlSecErrorsSafeString(xmlSecKeyDataStoreGetName(store)),
                        NULL,
                        XMLSEC_ERRORS_R_CERT_HAS_EXPIRED,
                        "cert with subject name %s has expired",
                        cert->subjectName);
	    break;
	case SEC_ERROR_REVOKED_CERTIFICATE:
            xmlSecError(XMLSEC_ERRORS_HERE,
                        xmlSecErrorsSafeString(xmlSecKeyDataStoreGetName(store)),
                        NULL,
                        XMLSEC_ERRORS_R_CERT_REVOKED,
                        "cert with subject name %s has been revoked",
                        cert->subjectName);
	    break;
	default:
            xmlSecError(XMLSEC_ERRORS_HERE,
                        xmlSecErrorsSafeString(xmlSecKeyDataStoreGetName(store)),
                        NULL,
                        XMLSEC_ERRORS_R_CERT_VERIFY_FAILED,
						"cert with subject name %s could not be verified, errcode %d",
						cert->subjectName,
			PORT_GetError());
	    break;
    }
   
    return (NULL);
}

/**
 * xmlSecNssX509StoreAdoptCert:
 * @store:              the pointer to X509 key data store klass.
 * @cert:               the pointer to NSS X509 certificate.
 * @type:               the certificate type (trusted/untrusted).
 *
 * Adds trusted (root) or untrusted certificate to the store.
 *
 * Returns: 0 on success or a negative value if an error occurs.
 */
int
xmlSecNssX509StoreAdoptCert(xmlSecKeyDataStorePtr store, CERTCertificate* cert, xmlSecKeyDataType type ATTRIBUTE_UNUSED) {
    xmlSecNssX509StoreCtxPtr ctx;
    int ret;

    xmlSecAssert2(xmlSecKeyDataStoreCheckId(store, xmlSecNssX509StoreId), -1);
    xmlSecAssert2(cert != NULL, -1);

    ctx = xmlSecNssX509StoreGetCtx(store);
    xmlSecAssert2(ctx != NULL, -1);

    if(ctx->certsList == NULL) {
        ctx->certsList = CERT_NewCertList();
        if(ctx->certsList == NULL) {
            xmlSecError(XMLSEC_ERRORS_HERE,
                        xmlSecErrorsSafeString(xmlSecKeyDataStoreGetName(store)),
                        "CERT_NewCertList",
                        XMLSEC_ERRORS_R_CRYPTO_FAILED,
						"error code=%d", PORT_GetError());
            return(-1);
        }
    }

    ret = CERT_AddCertToListTail(ctx->certsList, cert);
    if(ret != SECSuccess) {
        xmlSecError(XMLSEC_ERRORS_HERE,
                    xmlSecErrorsSafeString(xmlSecKeyDataStoreGetName(store)),
                    "CERT_AddCertToListTail",
                    XMLSEC_ERRORS_R_CRYPTO_FAILED,
					"error code=%d", PORT_GetError());
        return(-1);
    }

    return(0);
}

static int
xmlSecNssX509StoreInitialize(xmlSecKeyDataStorePtr store) {
    xmlSecNssX509StoreCtxPtr ctx;
    xmlSecAssert2(xmlSecKeyDataStoreCheckId(store, xmlSecNssX509StoreId), -1);

    ctx = xmlSecNssX509StoreGetCtx(store);
    xmlSecAssert2(ctx != NULL, -1);

    memset(ctx, 0, sizeof(xmlSecNssX509StoreCtx));

    return(0);    
}

static void
xmlSecNssX509StoreFinalize(xmlSecKeyDataStorePtr store) {
    xmlSecNssX509StoreCtxPtr ctx;
    xmlSecAssert(xmlSecKeyDataStoreCheckId(store, xmlSecNssX509StoreId));

    ctx = xmlSecNssX509StoreGetCtx(store);
    xmlSecAssert(ctx != NULL);
    
    if (ctx->certsList) {
	CERT_DestroyCertList(ctx->certsList);
	ctx->certsList = NULL;
    }

    memset(ctx, 0, sizeof(xmlSecNssX509StoreCtx));
}


/*****************************************************************************
 *
 * Low-level x509 functions
 *
 *****************************************************************************/
static CERTCertificate*		
xmlSecNssX509FindCert(xmlChar *subjectName, xmlChar *issuerName, 
		      xmlChar *issuerSerial, xmlChar *ski) {
    CERTCertificate *cert = NULL;
    xmlChar         *p = NULL;
    CERTName *name = NULL;
    SECItem *nameitem = NULL;
    PRArenaPool *arena = NULL;

    if (subjectName != NULL) {
	p = xmlSecNssX509NameRead(subjectName, xmlStrlen(subjectName));
	if (p == NULL) {
            xmlSecError(XMLSEC_ERRORS_HERE,
                        NULL,
                        "xmlSecNssX509NameRead",
                        XMLSEC_ERRORS_R_XMLSEC_FAILED,
                        "subject=%s",
                        xmlSecErrorsSafeString(subjectName));
	    goto done;
	}

	arena = PORT_NewArena(DER_DEFAULT_CHUNKSIZE);
	if (arena == NULL) {
            xmlSecError(XMLSEC_ERRORS_HERE,
                        NULL,
                        "PORT_NewArena",
                        XMLSEC_ERRORS_R_CRYPTO_FAILED,
                        XMLSEC_ERRORS_NO_MESSAGE);
	    goto done;
	}

	name = CERT_AsciiToName((char*)p);
	if (name == NULL) {
            xmlSecError(XMLSEC_ERRORS_HERE,
                        NULL,
                        "CERT_AsciiToName",
                        XMLSEC_ERRORS_R_XMLSEC_FAILED,
                        XMLSEC_ERRORS_NO_MESSAGE);
	    goto done;
	}

	nameitem = SEC_ASN1EncodeItem(arena, NULL, (void *)name,
				      SEC_ASN1_GET(CERT_NameTemplate));
	if (nameitem == NULL) {
            xmlSecError(XMLSEC_ERRORS_HERE,
                        NULL,
                        "SEC_ASN1EncodeItem",
                        XMLSEC_ERRORS_R_XMLSEC_FAILED,
						"error code=%d", PORT_GetError());
	    goto done;
	}

	cert = CERT_FindCertByName(CERT_GetDefaultCertDB(), nameitem);
	goto done;
    }

    if((issuerName != NULL) && (issuerSerial != NULL)) {
	CERTIssuerAndSN issuerAndSN;

	p = xmlSecNssX509NameRead(issuerName, xmlStrlen(issuerName));
	if (p == NULL) {
            xmlSecError(XMLSEC_ERRORS_HERE,
                        NULL,
                        "xmlSecNssX509NameRead",
                        XMLSEC_ERRORS_R_XMLSEC_FAILED,
                        "issuer=%s",
                        xmlSecErrorsSafeString(issuerName));
	    goto done;
	}

	arena = PORT_NewArena(DER_DEFAULT_CHUNKSIZE);
	if (arena == NULL) {
            xmlSecError(XMLSEC_ERRORS_HERE,
                        NULL,
                        "PORT_NewArena",
                        XMLSEC_ERRORS_R_CRYPTO_FAILED,
                        XMLSEC_ERRORS_NO_MESSAGE);
	    goto done;
	}

	name = CERT_AsciiToName((char*)p);
	if (name == NULL) {
            xmlSecError(XMLSEC_ERRORS_HERE,
                        NULL,
                        "CERT_AsciiToName",
                        XMLSEC_ERRORS_R_XMLSEC_FAILED,
                        XMLSEC_ERRORS_NO_MESSAGE);
	    goto done;
	}

	nameitem = SEC_ASN1EncodeItem(arena, NULL, (void *)name,
				      SEC_ASN1_GET(CERT_NameTemplate));
	if (nameitem == NULL) {
            xmlSecError(XMLSEC_ERRORS_HERE,
                        NULL,
                        "SEC_ASN1EncodeItem",
                        XMLSEC_ERRORS_R_XMLSEC_FAILED,
						"error code=%d", PORT_GetError());
	    goto done;
	}

	memset(&issuerAndSN, 0, sizeof(issuerAndSN));

	issuerAndSN.derIssuer.data = nameitem->data;
	issuerAndSN.derIssuer.len = nameitem->len;

	/* TBD: serial num can be arbitrarily long */
	xmlSecNssNumToItem(&issuerAndSN.serialNumber, PORT_Atoi((char *)issuerSerial));

	cert = CERT_FindCertByIssuerAndSN(CERT_GetDefaultCertDB(), 
					  &issuerAndSN);
	SECITEM_FreeItem(&issuerAndSN.serialNumber, PR_FALSE);
	goto done;
    }

    if(ski != NULL) {
	SECItem subjKeyID;
	int len;

	len = xmlSecBase64Decode(ski, (xmlSecByte*)ski, xmlStrlen(ski));
        if(len < 0) {
            xmlSecError(XMLSEC_ERRORS_HERE,
                        NULL,
                        "xmlSecBase64Decode",
                        XMLSEC_ERRORS_R_XMLSEC_FAILED,
                        "ski=%s",
                        xmlSecErrorsSafeString(ski));
	    goto done;
        }

	memset(&subjKeyID, 0, sizeof(subjKeyID));
	subjKeyID.data = ski;
	subjKeyID.len = xmlStrlen(ski);
        cert = CERT_FindCertBySubjectKeyID(CERT_GetDefaultCertDB(), 
					   &subjKeyID);
    }

done:
    if (p != NULL) {
	PORT_Free(p);
    }
    if (arena != NULL) {
	PORT_FreeArena(arena, PR_FALSE);
    }
    if (name != NULL) {
	CERT_DestroyName(name);
    }

    return(cert);
}

static xmlSecByte *
xmlSecNssX509NameRead(xmlSecByte *str, int len) {
    xmlSecByte name[256];
    xmlSecByte value[256];
    xmlSecByte *retval = NULL;
    xmlSecByte *p = NULL;
    int nameLen, valueLen;

    xmlSecAssert2(str != NULL, NULL);
    
    /* return string should be no longer than input string */
    retval = (xmlSecByte *)PORT_Alloc(len+1);
    if(retval == NULL) {
	xmlSecError(XMLSEC_ERRORS_HERE,
		    NULL,
		    "PORT_Alloc",
		    XMLSEC_ERRORS_R_MALLOC_FAILED,
		    XMLSEC_ERRORS_NO_MESSAGE);
	return(NULL);
    }
    p = retval;
    
    while(len > 0) {
	/* skip spaces after comma or semicolon */
	while((len > 0) && isspace(*str)) {
	    ++str; --len;
	}

	nameLen = xmlSecNssX509NameStringRead(&str, &len, name, sizeof(name), '=', 0);	
	if(nameLen < 0) {
	    xmlSecError(XMLSEC_ERRORS_HERE,
			NULL,
			"xmlSecNssX509NameStringRead",
			XMLSEC_ERRORS_R_XMLSEC_FAILED,
			XMLSEC_ERRORS_NO_MESSAGE);
	    goto done;
	}
	memcpy(p, name, nameLen);
	p+=nameLen;
	*p++='=';
	if(len > 0) {
	    ++str; --len;
	    if((*str) == '\"') {
		valueLen = xmlSecNssX509NameStringRead(&str, &len, 
					value, sizeof(value), '"', 1);	
		if(valueLen < 0) {
		    xmlSecError(XMLSEC_ERRORS_HERE,
				NULL,
				"xmlSecNssX509NameStringRead",
				XMLSEC_ERRORS_R_XMLSEC_FAILED,
				XMLSEC_ERRORS_NO_MESSAGE);
		    goto done;
    		}
		/* skip spaces before comma or semicolon */
		while((len > 0) && isspace(*str)) {
		    ++str; --len;
		}
		if((len > 0) && ((*str) != ',')) {
		    xmlSecError(XMLSEC_ERRORS_HERE,
				NULL,
				NULL,
				XMLSEC_ERRORS_R_INVALID_DATA,
				"comma is expected");
		    goto done;
		}
		if(len > 0) {
		    ++str; --len;
		}
		*p++='\"';
		memcpy(p, value, valueLen);
		p+=valueLen;
		*p++='\"';
	    } else if((*str) == '#') {
		/* TODO: read octect values */
		xmlSecError(XMLSEC_ERRORS_HERE,
			    NULL,
			    NULL,
			    XMLSEC_ERRORS_R_INVALID_DATA,
			    "reading octect values is not implemented yet");
		goto done;
	    } else {
		valueLen = xmlSecNssX509NameStringRead(&str, &len, 
					value, sizeof(value), ',', 1);	
		if(valueLen < 0) {
		    xmlSecError(XMLSEC_ERRORS_HERE,
				NULL,
				"xmlSecNssX509NameStringRead",
				XMLSEC_ERRORS_R_XMLSEC_FAILED,
				XMLSEC_ERRORS_NO_MESSAGE);
		    goto done;
    		}
		memcpy(p, value, valueLen);
		p+=valueLen;
		if (len > 0)
		    *p++=',';
	    } 			
	} else {
	    valueLen = 0;
	}
	if(len > 0) {
	    ++str; --len;
	}	
    }

    *p = 0;
    return(retval);
    
done:
    PORT_Free(retval);
    return (NULL);
}

static int 
xmlSecNssX509NameStringRead(xmlSecByte **str, int *strLen, 
			    xmlSecByte *res, int resLen,
			    xmlSecByte delim, int ingoreTrailingSpaces) {
    xmlSecByte *p, *q, *nonSpace; 

    xmlSecAssert2(str != NULL, -1);
    xmlSecAssert2(strLen != NULL, -1);
    xmlSecAssert2(res != NULL, -1);
    
    p = (*str);
    nonSpace = q = res;
    while(((p - (*str)) < (*strLen)) && ((*p) != delim) && ((q - res) < resLen)) { 
	if((*p) != '\\') {
	    if(ingoreTrailingSpaces && !isspace(*p)) {
		nonSpace = q;	
	    }
	    *(q++) = *(p++);
	} else {
	    ++p;
	    nonSpace = q;    
	    if(xmlSecIsHex((*p))) {
		if((p - (*str) + 1) >= (*strLen)) {
		    xmlSecError(XMLSEC_ERRORS_HERE,
				NULL,
				NULL,
				XMLSEC_ERRORS_R_INVALID_DATA,
				"two hex digits expected");
	    	    return(-1);
		}
		*(q++) = xmlSecGetHex(p[0]) * 16 + xmlSecGetHex(p[1]);
		p += 2;
	    } else {
		if(((++p) - (*str)) >= (*strLen)) {
		    xmlSecError(XMLSEC_ERRORS_HERE,
				NULL,
				NULL,
				XMLSEC_ERRORS_R_INVALID_DATA,
				"escaped symbol missed");
		    return(-1);
		}
		*(q++) = *(p++); 
	    }
	}	    
    }
    if(((p - (*str)) < (*strLen)) && ((*p) != delim)) {
	xmlSecError(XMLSEC_ERRORS_HERE,
		    NULL,
		    NULL,
		    XMLSEC_ERRORS_R_INVALID_SIZE,
		    "buffer is too small");
	return(-1);
    }
    (*strLen) -= (p - (*str));
    (*str) = p;
    return((ingoreTrailingSpaces) ? nonSpace - res + 1 : q - res);
}

/* code lifted from NSS */
static void
xmlSecNssNumToItem(SECItem *it, unsigned long ui)
{
    unsigned char bb[5];
    int len;

    bb[0] = 0;
    bb[1] = (unsigned char) (ui >> 24);
    bb[2] = (unsigned char) (ui >> 16);
    bb[3] = (unsigned char) (ui >> 8);
    bb[4] = (unsigned char) (ui);

    /*
    ** Small integers are encoded in a single byte. Larger integers
    ** require progressively more space.
    */
    if (ui > 0x7f) {
        if (ui > 0x7fff) {
            if (ui > 0x7fffffL) {
                if (ui >= 0x80000000L) {
                    len = 5;
                } else {
                    len = 4;
                }
            } else {
                len = 3;
            }
        } else {
            len = 2;
        }
    } else {
        len = 1;
    }

    it->data = (unsigned char *)PORT_Alloc(len);
    if (it->data == NULL) {
        return;
    }

    it->len = len;
    PORT_Memcpy(it->data, bb + (sizeof(bb) - len), len);
}
#endif /* XMLSEC_NO_X509 */