Revision 13ce52be1b9b0d5b409d079b846b748c069b2b69 authored by Adam Langley on 20 June 2014, 19:00:00 UTC, committed by Emilia Kasper on 05 September 2014, 10:22:50 UTC
Fix a bug in handling of 128 byte long PSK identity in psk_client_callback. OpenSSL supports PSK identities of up to (and including) 128 bytes in length. PSK identity is obtained via the psk_client_callback, implementors of which are expected to provide a NULL-terminated identity. However, the callback is invoked with only 128 bytes of storage thus making it impossible to return a 128 byte long identity and the required additional NULL byte. This CL fixes the issue by passing in a 129 byte long buffer into the psk_client_callback. As a safety precaution, this CL also zeroes out the buffer before passing it into the callback, uses strnlen for obtaining the length of the identity returned by the callback, and aborts the handshake if the identity (without the NULL terminator) is longer than 128 bytes. (Original patch amended to achieve strnlen in a different way.) Reviewed-by: Rich Salz <rsalz@openssl.org> (cherry picked from commit be0d851732bad7370640702bc9c4a33189ede287)
1 parent 11853c5
selfsign.c
/* NOCW */
/* cc -o ssdemo -I../include selfsign.c ../libcrypto.a */
#include <stdio.h>
#include <stdlib.h>
#include <openssl/pem.h>
#include <openssl/conf.h>
#include <openssl/x509v3.h>
int mkit(X509 **x509p, EVP_PKEY **pkeyp, int bits, int serial, int days);
int main()
{
BIO *bio_err;
X509 *x509=NULL;
EVP_PKEY *pkey=NULL;
CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_ON);
bio_err=BIO_new_fp(stderr, BIO_NOCLOSE);
mkit(&x509,&pkey,512,0,365);
RSA_print_fp(stdout,pkey->pkey.rsa,0);
X509_print_fp(stdout,x509);
PEM_write_PrivateKey(stdout,pkey,NULL,NULL,0,NULL, NULL);
PEM_write_X509(stdout,x509);
X509_free(x509);
EVP_PKEY_free(pkey);
#ifdef CUSTOM_EXT
/* Only needed if we add objects or custom extensions */
X509V3_EXT_cleanup();
OBJ_cleanup();
#endif
CRYPTO_mem_leaks(bio_err);
BIO_free(bio_err);
return(0);
}
#ifdef WIN16
# define MS_CALLBACK _far _loadds
# define MS_FAR _far
#else
# define MS_CALLBACK
# define MS_FAR
#endif
static void MS_CALLBACK callback(p, n, arg)
int p;
int n;
void *arg;
{
char c='B';
if (p == 0) c='.';
if (p == 1) c='+';
if (p == 2) c='*';
if (p == 3) c='\n';
fputc(c,stderr);
}
int mkit(x509p,pkeyp,bits,serial,days)
X509 **x509p;
EVP_PKEY **pkeyp;
int bits;
int serial;
int days;
{
X509 *x;
EVP_PKEY *pk;
RSA *rsa;
X509_NAME *name=NULL;
X509_NAME_ENTRY *ne=NULL;
X509_EXTENSION *ex=NULL;
if ((pkeyp == NULL) || (*pkeyp == NULL))
{
if ((pk=EVP_PKEY_new()) == NULL)
{
abort();
return(0);
}
}
else
pk= *pkeyp;
if ((x509p == NULL) || (*x509p == NULL))
{
if ((x=X509_new()) == NULL)
goto err;
}
else
x= *x509p;
rsa=RSA_generate_key(bits,RSA_F4,callback,NULL);
if (!EVP_PKEY_assign_RSA(pk,rsa))
{
abort();
goto err;
}
rsa=NULL;
X509_set_version(x,3);
ASN1_INTEGER_set(X509_get_serialNumber(x),serial);
X509_gmtime_adj(X509_get_notBefore(x),0);
X509_gmtime_adj(X509_get_notAfter(x),(long)60*60*24*days);
X509_set_pubkey(x,pk);
name=X509_get_subject_name(x);
/* This function creates and adds the entry, working out the
* correct string type and performing checks on its length.
* Normally we'd check the return value for errors...
*/
X509_NAME_add_entry_by_txt(name,"C",
MBSTRING_ASC, "UK", -1, -1, 0);
X509_NAME_add_entry_by_txt(name,"CN",
MBSTRING_ASC, "OpenSSL Group", -1, -1, 0);
X509_set_issuer_name(x,name);
/* Add extension using V3 code: we can set the config file as NULL
* because we wont reference any other sections. We can also set
* the context to NULL because none of these extensions below will need
* to access it.
*/
ex = X509V3_EXT_conf_nid(NULL, NULL, NID_netscape_cert_type, "server");
X509_add_ext(x,ex,-1);
X509_EXTENSION_free(ex);
ex = X509V3_EXT_conf_nid(NULL, NULL, NID_netscape_comment,
"example comment extension");
X509_add_ext(x,ex,-1);
X509_EXTENSION_free(ex);
ex = X509V3_EXT_conf_nid(NULL, NULL, NID_netscape_ssl_server_name,
"www.openssl.org");
X509_add_ext(x,ex,-1);
X509_EXTENSION_free(ex);
#if 0
/* might want something like this too.... */
ex = X509V3_EXT_conf_nid(NULL, NULL, NID_basic_constraints,
"critical,CA:TRUE");
X509_add_ext(x,ex,-1);
X509_EXTENSION_free(ex);
#endif
#ifdef CUSTOM_EXT
/* Maybe even add our own extension based on existing */
{
int nid;
nid = OBJ_create("1.2.3.4", "MyAlias", "My Test Alias Extension");
X509V3_EXT_add_alias(nid, NID_netscape_comment);
ex = X509V3_EXT_conf_nid(NULL, NULL, nid,
"example comment alias");
X509_add_ext(x,ex,-1);
X509_EXTENSION_free(ex);
}
#endif
if (!X509_sign(x,pk,EVP_md5()))
goto err;
*x509p=x;
*pkeyp=pk;
return(1);
err:
return(0);
}

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