Prevent cross-site forgery attacks on lukemftpd(8) due to splitting

long commands into multiple requests. [09:01]

Fix incorrect OpenSSL checks for malformed signatures due to invalid
check of return value from EVP_VerifyFinal(), DSA_verify, and
DSA_do_verify. [09:02]

Security:	FreeBSD-SA-09:01.lukemftpd
Security:	FreeBSD-SA-09:02.openssl
Obtained from:	NetBSD [SA-09:01]
Obtained from:	OpenSSL Project [SA-09:02]
Approved by:	so (simon)

contrib/lukemftpd/src/extern.h

@@ -139,7 +139,7 @@ void	feat(void);
 void	format_path(char *, const char *);
 int	ftpd_pclose(FILE *);
 FILE   *ftpd_popen(char *[], const char *, int);
-char   *getline(char *, int, FILE *);
+int	getline(char *, int, FILE *);
 void	init_curclass(void);
 void	logxfer(const char *, off_t, const char *, const char *,
 	    const struct timeval *, const char *);

contrib/lukemftpd/src/ftpcmd.y

@@ -1363,8 +1363,12 @@ lookup(struct tab *p, const char *cmd)
 
 /*
  * getline - a hacked up version of fgets to ignore TELNET escape codes.
+ *	`s' is the buffer to read into.
+ *	`n' is the 1 less than the size of the buffer, to allow trailing NUL
+ *	`iop' is the FILE to read from.
+ *	Returns 0 on success, -1 on EOF, -2 if the command was too long.
  */
-char *
+int
 getline(char *s, int n, FILE *iop)
 {
 	int c;
@@ -1379,7 +1383,7 @@ getline(char *s, int n, FILE *iop)
 			if (ftpd_debug)
 				syslog(LOG_DEBUG, "command: %s", s);
 			tmpline[0] = '\0';
-			return(s);
+			return(0);
 		}
 		if (c == 0)
 			tmpline[0] = '\0';
@@ -1418,11 +1422,25 @@ getline(char *s, int n, FILE *iop)
 		    }
 		}
 		*cs++ = c;
-		if (--n <= 0 || c == '\n')
+		if (--n <= 0) {
+			/*
+			 * If command doesn't fit into buffer, discard the
+			 * rest of the command and indicate truncation.
+			 * This prevents the command to be split up into
+			 * multiple commands.
+			 */
+			if (ftpd_debug)
+				syslog(LOG_DEBUG,
+				    "command too long, last char: %d", c);
+			while (c != '\n' && (c = getc(iop)) != EOF)
+				continue;
+			return (-2);
+		}
+		if (c == '\n')
 			break;
 	}
 	if (c == EOF && cs == s)
-		return (NULL);
+		return (-1);
 	*cs++ = '\0';
 	if (ftpd_debug) {
 		if ((curclass.type != CLASS_GUEST &&
@@ -1444,7 +1462,7 @@ getline(char *s, int n, FILE *iop)
 			syslog(LOG_DEBUG, "command: %.*s", len, s);
 		}
 	}
-	return (s);
+	return (0);
 }
 
 void
@@ -1458,15 +1476,20 @@ ftp_handle_line(char *cp)
 void
 ftp_loop(void)
 {
+	int ret;
 
 	while (1) {
 		(void) alarm(curclass.timeout);
-		if (getline(cbuf, sizeof(cbuf)-1, stdin) == NULL) {
+		ret = getline(cbuf, sizeof(cbuf)-1, stdin);
+		(void) alarm(0);
+		if (ret == -1) {
 			reply(221, "You could at least say goodbye.");
 			dologout(0);
+		} else if (ret == -2) {
+			reply(500, "Command too long.");
+		} else {
+			ftp_handle_line(cbuf);
 		}
-		(void) alarm(0);
-		ftp_handle_line(cbuf);
 	}
 	/*NOTREACHED*/
 }

contrib/lukemftpd/src/ftpd.c

@@ -1,4 +1,4 @@
-/*	$NetBSD: ftpd.c,v 1.176 2006/05/09 20:18:06 mrg Exp $	*/
+/*	$NetBSD: ftpd.c,v 1.187 2008/09/13 03:30:35 lukem Exp $	*/
 
 /*
  * Copyright (c) 1997-2004 The NetBSD Foundation, Inc.
@@ -2896,6 +2896,7 @@ static int
 handleoobcmd()
 {
 	char *cp;
+	int ret;
 
 	if (!urgflag)
 		return (0);
@@ -2904,9 +2905,14 @@ handleoobcmd()
 	if (!transflag)
 		return (0);
 	cp = tmpline;
-	if (getline(cp, sizeof(tmpline), stdin) == NULL) {
+	ret = getline(cp, sizeof(tmpline)-1, stdin);
+	if (ret == -1) {
 		reply(221, "You could at least say goodbye.");
 		dologout(0);
+	} else if (ret == -2) {
+		/* Ignore truncated command */
+		/* XXX: abort xfer with "500 command too long", & return 1 ? */
+		return 0;
 	}
 		/*
 		 * Manually parse OOB commands, because we can't

crypto/openssl/apps/speed.c

@@ -2038,7 +2038,7 @@ int MAIN(int argc, char **argv)
 				{
 				ret=RSA_verify(NID_md5_sha1, buf,36, buf2,
 					rsa_num, rsa_key[j]);
-				if (ret == 0)
+				if (ret <= 0)
 					{
 					BIO_printf(bio_err,
 						"RSA verify failure\n");

crypto/openssl/apps/spkac.c

@@ -285,7 +285,7 @@ bad:
 	pkey = NETSCAPE_SPKI_get_pubkey(spki);
 	if(verify) {
 		i = NETSCAPE_SPKI_verify(spki, pkey);
-		if(i) BIO_printf(bio_err, "Signature OK\n");
+		if (i > 0) BIO_printf(bio_err, "Signature OK\n");
 		else {
 			BIO_printf(bio_err, "Signature Failure\n");
 			ERR_print_errors(bio_err);

crypto/openssl/apps/verify.c

@@ -266,7 +266,7 @@ static int check(X509_STORE *ctx, char *file, STACK_OF(X509) *uchain, STACK_OF(X
 
 	ret=0;
 end:
-	if (i)
+	if (i > 0)
 		{
 		fprintf(stdout,"OK\n");
 		ret=1;
@@ -367,4 +367,3 @@ static int MS_CALLBACK cb(int ok, X509_STORE_CTX *ctx)
 		ERR_clear_error();
 	return(ok);
 	}
-

crypto/openssl/apps/x509.c

@@ -1144,7 +1144,7 @@ static int x509_certify(X509_STORE *ctx, char *CAfile, const EVP_MD *digest,
 	/* NOTE: this certificate can/should be self signed, unless it was
 	 * a certificate request in which case it is not. */
 	X509_STORE_CTX_set_cert(&xsc,x);
-	if (!reqfile && !X509_verify_cert(&xsc))
+	if (!reqfile && X509_verify_cert(&xsc) <= 0)
 		goto end;
 
 	if (!X509_check_private_key(xca,pkey))

crypto/openssl/ssl/s2_clnt.c

@@ -1044,7 +1044,7 @@ int ssl2_set_certificate(SSL *s, int type, int len, const unsigned char *data)
 
 	i=ssl_verify_cert_chain(s,sk);
 		
-	if ((s->verify_mode != SSL_VERIFY_NONE) && (!i))
+	if ((s->verify_mode != SSL_VERIFY_NONE) && (i <= 0))
 		{
 		SSLerr(SSL_F_SSL2_SET_CERTIFICATE,SSL_R_CERTIFICATE_VERIFY_FAILED);
 		goto err;

crypto/openssl/ssl/s2_srvr.c

@@ -1054,7 +1054,7 @@ static int request_certificate(SSL *s)
 
 	i=ssl_verify_cert_chain(s,sk);
 
-	if (i)	/* we like the packet, now check the chksum */
+	if (i > 0)	/* we like the packet, now check the chksum */
 		{
 		EVP_MD_CTX ctx;
 		EVP_PKEY *pkey=NULL;
@@ -1083,7 +1083,7 @@ static int request_certificate(SSL *s)
 		EVP_PKEY_free(pkey);
 		EVP_MD_CTX_cleanup(&ctx);
 
-		if (i) 
+		if (i > 0) 
 			{
 			if (s->session->peer != NULL)
 				X509_free(s->session->peer);

crypto/openssl/ssl/s3_clnt.c

@@ -883,7 +883,7 @@ int ssl3_get_server_certificate(SSL *s)
 		}
 
 	i=ssl_verify_cert_chain(s,sk);
-	if ((s->verify_mode != SSL_VERIFY_NONE) && (!i)
+	if ((s->verify_mode != SSL_VERIFY_NONE) && (i <= 0)
 #ifndef OPENSSL_NO_KRB5
 	        && (s->s3->tmp.new_cipher->algorithms & (SSL_MKEY_MASK|SSL_AUTH_MASK))
 	        != (SSL_aKRB5|SSL_kKRB5)
@@ -1368,7 +1368,7 @@ int ssl3_get_key_exchange(SSL *s)
 			EVP_VerifyUpdate(&md_ctx,&(s->s3->client_random[0]),SSL3_RANDOM_SIZE);
 			EVP_VerifyUpdate(&md_ctx,&(s->s3->server_random[0]),SSL3_RANDOM_SIZE);
 			EVP_VerifyUpdate(&md_ctx,param,param_len);
-			if (!EVP_VerifyFinal(&md_ctx,p,(int)n,pkey))
+			if (EVP_VerifyFinal(&md_ctx,p,(int)n,pkey) <= 0)
 				{
 				/* bad signature */
 				al=SSL_AD_DECRYPT_ERROR;
@@ -1386,7 +1386,7 @@ int ssl3_get_key_exchange(SSL *s)
 			EVP_VerifyUpdate(&md_ctx,&(s->s3->client_random[0]),SSL3_RANDOM_SIZE);
 			EVP_VerifyUpdate(&md_ctx,&(s->s3->server_random[0]),SSL3_RANDOM_SIZE);
 			EVP_VerifyUpdate(&md_ctx,param,param_len);
-			if (!EVP_VerifyFinal(&md_ctx,p,(int)n,pkey))
+			if (EVP_VerifyFinal(&md_ctx,p,(int)n,pkey) <= 0)
 				{
 				/* bad signature */
 				al=SSL_AD_DECRYPT_ERROR;

crypto/openssl/ssl/s3_srvr.c

@@ -2481,7 +2481,7 @@ int ssl3_get_client_certificate(SSL *s)
 	else
 		{
 		i=ssl_verify_cert_chain(s,sk);
-		if (!i)
+		if (i <= 0)
 			{
 			al=ssl_verify_alarm_type(s->verify_result);
 			SSLerr(SSL_F_SSL3_GET_CLIENT_CERTIFICATE,SSL_R_NO_CERTIFICATE_RETURNED);

crypto/openssl/ssl/ssltest.c

@@ -2072,7 +2072,7 @@ static int MS_CALLBACK app_verify_callback(X509_STORE_CTX *ctx, void *arg)
 
 	if (cb_arg->proxy_auth)
 		{
-		if (ok)
+		if (ok > 0)
 			{
 			const char *cond_end = NULL;