Commit bc501570 authored by Dr. Stephen Henson's avatar Dr. Stephen Henson
Browse files

Various X509 fixes. Disable broken certificate workarounds 

when X509_V_FLAG_X509_STRICT is set. Check for CRLSign in
CRL issuer certificates. Reject CRLs with unhandled (any)
critical extensions.
parent 91180d45

CHANGES

+8 −0
Original line number Diff line number Diff line
@@ -617,6 +617,14 @@ 


 Changes between 0.9.7c and 0.9.7d  [xx XXX XXXX]



  *) X509 verify fixes. Disable broken certificate workarounds when 

     X509_V_FLAGS_X509_STRICT is set. Check CRL issuer has cRLSign set if

     keyUsage extension present. Don't accept CRLs with unhandled critical

     extensions: since verify currently doesn't process CRL extensions this

     rejects a CRL with *any* critical extensions. Add new verify error codes

     for these cases.

     [Steve Henson]



  *) When creating an OCSP nonce use an OCTET STRING inside the extnValue.

     A clarification of RFC2560 will require the use of OCTET STRINGs and 

     some implementations cannot handle the current raw format. Since OpenSSL

crypto/x509/x509_txt.c

+6 −0
Original line number Diff line number Diff line
@@ -147,6 +147,12 @@ const char *X509_verify_cert_error_string(long n) 
	case X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION:

		return("unhandled critical extension");



	case X509_V_ERR_KEYUSAGE_NO_CRL_SIGN:

		return("key usage does not include CRL signing");



	case X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION:

		return("unhandled critical CRL extension");



	default:

		BIO_snprintf(buf,sizeof buf,"error number %ld",n);

		return(buf);

crypto/x509/x509_vfy.c

+48 −7
Original line number Diff line number Diff line
@@ -383,6 +383,7 @@ static int check_chain_purpose(X509_STORE_CTX *ctx) 
	/* Check all untrusted certificates */

	for (i = 0; i < ctx->last_untrusted; i++)

		{

		int ret;

		x = sk_X509_value(ctx->chain, i);

		if (!(ctx->flags & X509_V_FLAG_IGNORE_CRITICAL)

			&& (x->ex_flags & EXFLAG_CRITICAL))
@@ -393,7 +394,10 @@ static int check_chain_purpose(X509_STORE_CTX *ctx) 
			ok=cb(0,ctx);

			if (!ok) goto end;

			}

		if (!X509_check_purpose(x, ctx->purpose, i))

		ret = X509_check_purpose(x, ctx->purpose, i);

		if ((ret == 0)

			 || ((ctx->flags & X509_V_FLAG_X509_STRICT)

				&& (ret != 1)))

			{

			if (i)

				ctx->error = X509_V_ERR_INVALID_CA;
@@ -537,6 +541,14 @@ static int check_crl(X509_STORE_CTX *ctx, X509_CRL *crl) 


	if(issuer)

		{

		/* Check for cRLSign bit if keyUsage present */

		if ((issuer->ex_flags & EXFLAG_KUSAGE) &&

			!(issuer->ex_kusage & KU_CRL_SIGN))

			{

			ctx->error = X509_V_ERR_KEYUSAGE_NO_CRL_SIGN;

			ok = ctx->verify_cb(0, ctx);

			if(!ok) goto err;

			}



		/* Attempt to get issuer certificate public key */

		ikey = X509_get_pubkey(issuer);
@@ -611,17 +623,46 @@ static int cert_crl(X509_STORE_CTX *ctx, X509_CRL *crl, X509 *x) 
	{

	int idx, ok;

	X509_REVOKED rtmp;

	STACK_OF(X509_EXTENSION) *exts;

	X509_EXTENSION *ext;

	/* Look for serial number of certificate in CRL */

	rtmp.serialNumber = X509_get_serialNumber(x);

	idx = sk_X509_REVOKED_find(crl->crl->revoked, &rtmp);

	/* Not found: OK */

	if(idx == -1) return 1;

	/* Otherwise revoked: want something cleverer than

	/* If found assume revoked: want something cleverer than

	 * this to handle entry extensions in V2 CRLs.

	 */

	if(idx >= 0)

		{

		ctx->error = X509_V_ERR_CERT_REVOKED;

		ok = ctx->verify_cb(0, ctx);

	return ok;

		if (!ok) return 0;

		}



	if (ctx->flags & X509_V_FLAG_IGNORE_CRITICAL)

		return 1;



	/* See if we have any critical CRL extensions: since we

	 * currently don't handle any CRL extensions the CRL must be

	 * rejected. 

	 * This code accesses the X509_CRL structure directly: applications

	 * shouldn't do this.

	 */



	exts = crl->crl->extensions;



	for (idx = 0; idx < sk_X509_EXTENSION_num(exts); idx++)

		{

		ext = sk_X509_EXTENSION_value(exts, idx);

		if (ext->critical > 0)

			{

			ctx->error =

				X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION;

			ok = ctx->verify_cb(0, ctx);

			if(!ok) return 0;

			break;

			}

		}

	return 1;

	}



static int internal_verify(X509_STORE_CTX *ctx)

crypto/x509/x509_vfy.h

+14 −5
Original line number Diff line number Diff line
@@ -305,17 +305,26 @@ struct x509_store_ctx_st /* X509_STORE_CTX */ 


#define		X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER		33

#define		X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION		34

#define		X509_V_ERR_KEYUSAGE_NO_CRL_SIGN			35

#define		X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION	36



/* The application is not happy */

#define		X509_V_ERR_APPLICATION_VERIFICATION		50



/* Certificate verify flags */



#define	X509_V_FLAG_CB_ISSUER_CHECK		0x1	/* Send issuer+subject checks to verify_cb */

#define	X509_V_FLAG_USE_CHECK_TIME		0x2	/* Use check time instead of current time */

#define	X509_V_FLAG_CRL_CHECK			0x4	/* Lookup CRLs */

#define	X509_V_FLAG_CRL_CHECK_ALL		0x8	/* Lookup CRLs for whole chain */

#define	X509_V_FLAG_IGNORE_CRITICAL		0x10	/* Ignore unhandled critical extensions */

/* Send issuer+subject checks to verify_cb */

#define	X509_V_FLAG_CB_ISSUER_CHECK		0x1

/* Use check time instead of current time */

#define	X509_V_FLAG_USE_CHECK_TIME		0x2

/* Lookup CRLs */

#define	X509_V_FLAG_CRL_CHECK			0x4

/* Lookup CRLs for whole chain */

#define	X509_V_FLAG_CRL_CHECK_ALL		0x8

/* Ignore unhandled critical extensions */

#define	X509_V_FLAG_IGNORE_CRITICAL		0x10

/* Disable workarounds for broken certificates */

#define	X509_V_FLAG_X509_STRICT			0x20



int X509_OBJECT_idx_by_subject(STACK_OF(X509_OBJECT) *h, int type,

	     X509_NAME *name);

crypto/x509v3/v3_purp.c

+3 −2
Original line number Diff line number Diff line
@@ -3,7 +3,7 @@ 
 * project 2001.

 */

/* ====================================================================

 * Copyright (c) 1999-2001 The OpenSSL Project.  All rights reserved.

 * Copyright (c) 1999-2004 The OpenSSL Project.  All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions
@@ -415,6 +415,7 @@ static void x509v3_cache_extensions(X509 *x) 
 * 1 is a CA

 * 2 basicConstraints absent so "maybe" a CA

 * 3 basicConstraints absent but self signed V1.

 * 4 basicConstraints absent but keyUsage present and keyCertSign asserted.

 */



#define V1_ROOT (EXFLAG_V1|EXFLAG_SS)
@@ -436,7 +437,7 @@ static int ca_check(const X509 *x) 
	} else {

		if((x->ex_flags & V1_ROOT) == V1_ROOT) return 3;

		/* If key usage present it must have certSign so tolerate it */

		else if (x->ex_flags & EXFLAG_KUSAGE) return 3;

		else if (x->ex_flags & EXFLAG_KUSAGE) return 4;

		else return 2;

	}

}