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gecko-dev/security/nss/lib/ssl/ssl3ecc.c
nelson%bolyard.com aa48d36259 Curve-limited clients must not negotiate ECC ciphersuites unless they send the supported curve extension. This means that when they are nogotiating SSL 3.0 
and not TLS, they should not negotiate ECC ciphersuites at all.
Bug 341707.  r=rrelyea.
2006-07-19 01:40:17 +00:00

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/*
* SSL3 Protocol
*
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is the Netscape security libraries.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1994-2000
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Dr Vipul Gupta <vipul.gupta@sun.com> and
* Douglas Stebila <douglas@stebila.ca>, Sun Microsystems Laboratories
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
/* ECC code moved here from ssl3con.c */
/* $Id: ssl3ecc.c,v 1.15 2006/07/19 01:40:17 nelson%bolyard.com Exp $ */
#include "nssrenam.h"
#include "nss.h"
#include "cert.h"
#include "ssl.h"
#include "cryptohi.h" /* for DSAU_ stuff */
#include "keyhi.h"
#include "secder.h"
#include "secitem.h"
#include "sslimpl.h"
#include "sslproto.h"
#include "sslerr.h"
#include "prtime.h"
#include "prinrval.h"
#include "prerror.h"
#include "pratom.h"
#include "prthread.h"
#include "prinit.h"
#include "pk11func.h"
#include "secmod.h"
#include "nsslocks.h"
#include "ec.h"
#include "blapi.h"
#include <stdio.h>
#ifdef NSS_ENABLE_ECC
#ifndef PK11_SETATTRS
#define PK11_SETATTRS(x,id,v,l) (x)->type = (id); \
(x)->pValue=(v); (x)->ulValueLen = (l);
#endif
#define SSL_GET_SERVER_PUBLIC_KEY(sock, type) \
(ss->serverCerts[type].serverKeyPair ? \
ss->serverCerts[type].serverKeyPair->pubKey : NULL)
#define SSL_IS_CURVE_NEGOTIATED(ss, curveName) \
((curveName > ec_noName) && \
(curveName < ec_pastLastName) && \
((1UL << curveName) & ss->ssl3.hs.negotiatedECCurves) != 0)
/* Types and names of elliptic curves used in TLS */
typedef enum { ec_type_explicitPrime = 1,
ec_type_explicitChar2Curve = 2,
ec_type_named
} ECType;
typedef enum { ec_noName = 0,
ec_sect163k1 = 1,
ec_sect163r1 = 2,
ec_sect163r2 = 3,
ec_sect193r1 = 4,
ec_sect193r2 = 5,
ec_sect233k1 = 6,
ec_sect233r1 = 7,
ec_sect239k1 = 8,
ec_sect283k1 = 9,
ec_sect283r1 = 10,
ec_sect409k1 = 11,
ec_sect409r1 = 12,
ec_sect571k1 = 13,
ec_sect571r1 = 14,
ec_secp160k1 = 15,
ec_secp160r1 = 16,
ec_secp160r2 = 17,
ec_secp192k1 = 18,
ec_secp192r1 = 19,
ec_secp224k1 = 20,
ec_secp224r1 = 21,
ec_secp256k1 = 22,
ec_secp256r1 = 23,
ec_secp384r1 = 24,
ec_secp521r1 = 25,
ec_pastLastName
} ECName;
static SECStatus ssl3_CreateECDHEphemeralKeys(sslSocket *ss, ECName ec_curve);
#define supportedCurve(x) (((x) > ec_noName) && ((x) < ec_pastLastName))
/* Table containing OID tags for elliptic curves named in the
* ECC-TLS IETF draft.
*/
static const SECOidTag ecName2OIDTag[] = {
0,
SEC_OID_SECG_EC_SECT163K1, /* 1 */
SEC_OID_SECG_EC_SECT163R1, /* 2 */
SEC_OID_SECG_EC_SECT163R2, /* 3 */
SEC_OID_SECG_EC_SECT193R1, /* 4 */
SEC_OID_SECG_EC_SECT193R2, /* 5 */
SEC_OID_SECG_EC_SECT233K1, /* 6 */
SEC_OID_SECG_EC_SECT233R1, /* 7 */
SEC_OID_SECG_EC_SECT239K1, /* 8 */
SEC_OID_SECG_EC_SECT283K1, /* 9 */
SEC_OID_SECG_EC_SECT283R1, /* 10 */
SEC_OID_SECG_EC_SECT409K1, /* 11 */
SEC_OID_SECG_EC_SECT409R1, /* 12 */
SEC_OID_SECG_EC_SECT571K1, /* 13 */
SEC_OID_SECG_EC_SECT571R1, /* 14 */
SEC_OID_SECG_EC_SECP160K1, /* 15 */
SEC_OID_SECG_EC_SECP160R1, /* 16 */
SEC_OID_SECG_EC_SECP160R2, /* 17 */
SEC_OID_SECG_EC_SECP192K1, /* 18 */
SEC_OID_SECG_EC_SECP192R1, /* 19 */
SEC_OID_SECG_EC_SECP224K1, /* 20 */
SEC_OID_SECG_EC_SECP224R1, /* 21 */
SEC_OID_SECG_EC_SECP256K1, /* 22 */
SEC_OID_SECG_EC_SECP256R1, /* 23 */
SEC_OID_SECG_EC_SECP384R1, /* 24 */
SEC_OID_SECG_EC_SECP521R1, /* 25 */
};
static const PRUint16 curve2bits[] = {
0, /* ec_noName = 0, */
163, /* ec_sect163k1 = 1, */
163, /* ec_sect163r1 = 2, */
163, /* ec_sect163r2 = 3, */
193, /* ec_sect193r1 = 4, */
193, /* ec_sect193r2 = 5, */
233, /* ec_sect233k1 = 6, */
233, /* ec_sect233r1 = 7, */
239, /* ec_sect239k1 = 8, */
283, /* ec_sect283k1 = 9, */
283, /* ec_sect283r1 = 10, */
409, /* ec_sect409k1 = 11, */
409, /* ec_sect409r1 = 12, */
571, /* ec_sect571k1 = 13, */
571, /* ec_sect571r1 = 14, */
160, /* ec_secp160k1 = 15, */
160, /* ec_secp160r1 = 16, */
160, /* ec_secp160r2 = 17, */
192, /* ec_secp192k1 = 18, */
192, /* ec_secp192r1 = 19, */
224, /* ec_secp224k1 = 20, */
224, /* ec_secp224r1 = 21, */
256, /* ec_secp256k1 = 22, */
256, /* ec_secp256r1 = 23, */
384, /* ec_secp384r1 = 24, */
521, /* ec_secp521r1 = 25, */
65535 /* ec_pastLastName */
};
typedef struct Bits2CurveStr {
PRUint16 bits;
ECName curve;
} Bits2Curve;
static const Bits2Curve bits2curve [] = {
{ 192, ec_secp192r1 /* = 19, fast */ },
{ 160, ec_secp160r2 /* = 17, fast */ },
{ 160, ec_secp160k1 /* = 15, */ },
{ 160, ec_secp160r1 /* = 16, */ },
{ 163, ec_sect163k1 /* = 1, */ },
{ 163, ec_sect163r1 /* = 2, */ },
{ 163, ec_sect163r2 /* = 3, */ },
{ 192, ec_secp192k1 /* = 18, */ },
{ 193, ec_sect193r1 /* = 4, */ },
{ 193, ec_sect193r2 /* = 5, */ },
{ 224, ec_secp224r1 /* = 21, fast */ },
{ 224, ec_secp224k1 /* = 20, */ },
{ 233, ec_sect233k1 /* = 6, */ },
{ 233, ec_sect233r1 /* = 7, */ },
{ 239, ec_sect239k1 /* = 8, */ },
{ 256, ec_secp256r1 /* = 23, fast */ },
{ 256, ec_secp256k1 /* = 22, */ },
{ 283, ec_sect283k1 /* = 9, */ },
{ 283, ec_sect283r1 /* = 10, */ },
{ 384, ec_secp384r1 /* = 24, fast */ },
{ 409, ec_sect409k1 /* = 11, */ },
{ 409, ec_sect409r1 /* = 12, */ },
{ 521, ec_secp521r1 /* = 25, fast */ },
{ 571, ec_sect571k1 /* = 13, */ },
{ 571, ec_sect571r1 /* = 14, */ },
{ 65535, ec_noName }
};
typedef struct ECDHEKeyPairStr {
ssl3KeyPair * pair;
PRInt32 flag;
PRCallOnceType once;
} ECDHEKeyPair;
/* arrays of ECDHE KeyPairs */
static ECDHEKeyPair gECDHEKeyPairs[ec_pastLastName];
static SECStatus
ecName2params(PRArenaPool * arena, ECName curve, SECKEYECParams * params)
{
SECOidData *oidData = NULL;
if ((curve <= ec_noName) || (curve >= ec_pastLastName) ||
((oidData = SECOID_FindOIDByTag(ecName2OIDTag[curve])) == NULL)) {
PORT_SetError(SEC_ERROR_UNSUPPORTED_ELLIPTIC_CURVE);
return SECFailure;
}
SECITEM_AllocItem(arena, params, (2 + oidData->oid.len));
/*
* params->data needs to contain the ASN encoding of an object ID (OID)
* representing the named curve. The actual OID is in
* oidData->oid.data so we simply prepend 0x06 and OID length
*/
params->data[0] = SEC_ASN1_OBJECT_ID;
params->data[1] = oidData->oid.len;
memcpy(params->data + 2, oidData->oid.data, oidData->oid.len);
return SECSuccess;
}
static ECName
params2ecName(SECKEYECParams * params)
{
SECItem oid = { siBuffer, NULL, 0};
SECOidData *oidData = NULL;
ECName i;
/*
* params->data needs to contain the ASN encoding of an object ID (OID)
* representing a named curve. Here, we strip away everything
* before the actual OID and use the OID to look up a named curve.
*/
if (params->data[0] != SEC_ASN1_OBJECT_ID) return ec_noName;
oid.len = params->len - 2;
oid.data = params->data + 2;
if ((oidData = SECOID_FindOID(&oid)) == NULL) return ec_noName;
for (i = ec_noName + 1; i < ec_pastLastName; i++) {
if (ecName2OIDTag[i] == oidData->offset)
return i;
}
return ec_noName;
}
/* Caller must set hiLevel error code. */
static SECStatus
ssl3_ComputeECDHKeyHash(SECItem ec_params, SECItem server_ecpoint,
SSL3Random *client_rand, SSL3Random *server_rand,
SSL3Hashes *hashes, PRBool bypassPKCS11)
{
PRUint8 * hashBuf;
PRUint8 * pBuf;
SECStatus rv = SECSuccess;
unsigned int bufLen;
/*
* XXX For now, we only support named curves (the appropriate
* checks are made before this method is called) so ec_params
* takes up only two bytes. ECPoint needs to fit in 256 bytes
* (because the spec says the length must fit in one byte)
*/
PRUint8 buf[2*SSL3_RANDOM_LENGTH + 2 + 1 + 256];
bufLen = 2*SSL3_RANDOM_LENGTH + ec_params.len + 1 + server_ecpoint.len;
if (bufLen <= sizeof buf) {
hashBuf = buf;
} else {
hashBuf = PORT_Alloc(bufLen);
if (!hashBuf) {
return SECFailure;
}
}
memcpy(hashBuf, client_rand, SSL3_RANDOM_LENGTH);
pBuf = hashBuf + SSL3_RANDOM_LENGTH;
memcpy(pBuf, server_rand, SSL3_RANDOM_LENGTH);
pBuf += SSL3_RANDOM_LENGTH;
memcpy(pBuf, ec_params.data, ec_params.len);
pBuf += ec_params.len;
pBuf[0] = (PRUint8)(server_ecpoint.len);
pBuf += 1;
memcpy(pBuf, server_ecpoint.data, server_ecpoint.len);
pBuf += server_ecpoint.len;
PORT_Assert((unsigned int)(pBuf - hashBuf) == bufLen);
rv = ssl3_ComputeCommonKeyHash(hashBuf, bufLen, hashes, bypassPKCS11);
PRINT_BUF(95, (NULL, "ECDHkey hash: ", hashBuf, bufLen));
PRINT_BUF(95, (NULL, "ECDHkey hash: MD5 result", hashes->md5, MD5_LENGTH));
PRINT_BUF(95, (NULL, "ECDHkey hash: SHA1 result", hashes->sha, SHA1_LENGTH));
if (hashBuf != buf && hashBuf != NULL)
PORT_Free(hashBuf);
return rv;
}
/* Called from ssl3_SendClientKeyExchange(). */
SECStatus
ssl3_SendECDHClientKeyExchange(sslSocket * ss, SECKEYPublicKey * svrPubKey)
{
PK11SymKey * pms = NULL;
SECStatus rv = SECFailure;
PRBool isTLS;
CK_MECHANISM_TYPE target;
SECKEYPublicKey *pubKey = NULL; /* Ephemeral ECDH key */
SECKEYPrivateKey *privKey = NULL; /* Ephemeral ECDH key */
PORT_Assert( ss->opt.noLocks || ssl_HaveSSL3HandshakeLock(ss) );
PORT_Assert( ss->opt.noLocks || ssl_HaveXmitBufLock(ss));
isTLS = (PRBool)(ss->ssl3.pwSpec->version > SSL_LIBRARY_VERSION_3_0);
/* Generate ephemeral EC keypair */
/* XXX SHOULD CALL ssl3_CreateECDHEphemeralKeys here, instead! */
privKey = SECKEY_CreateECPrivateKey(&svrPubKey->u.ec.DEREncodedParams,
&pubKey, NULL);
if (!privKey || !pubKey) {
ssl_MapLowLevelError(SEC_ERROR_KEYGEN_FAIL);
rv = SECFailure;
goto loser;
}
PRINT_BUF(50, (ss, "ECDH public value:",
pubKey->u.ec.publicValue.data,
pubKey->u.ec.publicValue.len));
if (isTLS) target = CKM_TLS_MASTER_KEY_DERIVE_DH;
else target = CKM_SSL3_MASTER_KEY_DERIVE_DH;
/* Determine the PMS */
pms = PK11_PubDeriveWithKDF(privKey, svrPubKey, PR_FALSE, NULL, NULL,
CKM_ECDH1_DERIVE, target, CKA_DERIVE, 0,
CKD_NULL, NULL, NULL);
if (pms == NULL) {
SSL3AlertDescription desc = illegal_parameter;
(void)SSL3_SendAlert(ss, alert_fatal, desc);
ssl_MapLowLevelError(SSL_ERROR_CLIENT_KEY_EXCHANGE_FAILURE);
goto loser;
}
SECKEY_DestroyPrivateKey(privKey);
privKey = NULL;
rv = ssl3_InitPendingCipherSpec(ss, pms);
PK11_FreeSymKey(pms); pms = NULL;
if (rv != SECSuccess) {
ssl_MapLowLevelError(SSL_ERROR_CLIENT_KEY_EXCHANGE_FAILURE);
goto loser;
}
rv = ssl3_AppendHandshakeHeader(ss, client_key_exchange,
pubKey->u.ec.publicValue.len + 1);
if (rv != SECSuccess) {
goto loser; /* err set by ssl3_AppendHandshake* */
}
rv = ssl3_AppendHandshakeVariable(ss,
pubKey->u.ec.publicValue.data,
pubKey->u.ec.publicValue.len, 1);
SECKEY_DestroyPublicKey(pubKey);
pubKey = NULL;
if (rv != SECSuccess) {
goto loser; /* err set by ssl3_AppendHandshake* */
}
rv = SECSuccess;
loser:
if(pms) PK11_FreeSymKey(pms);
if(privKey) SECKEY_DestroyPrivateKey(privKey);
if(pubKey) SECKEY_DestroyPublicKey(pubKey);
return rv;
}
/*
** Called from ssl3_HandleClientKeyExchange()
*/
SECStatus
ssl3_HandleECDHClientKeyExchange(sslSocket *ss, SSL3Opaque *b,
PRUint32 length,
SECKEYPublicKey *srvrPubKey,
SECKEYPrivateKey *srvrPrivKey)
{
PK11SymKey * pms;
SECStatus rv;
SECKEYPublicKey clntPubKey;
CK_MECHANISM_TYPE target;
PRBool isTLS;
PORT_Assert( ss->opt.noLocks || ssl_HaveRecvBufLock(ss) );
PORT_Assert( ss->opt.noLocks || ssl_HaveSSL3HandshakeLock(ss) );
clntPubKey.keyType = ecKey;
clntPubKey.u.ec.DEREncodedParams.len =
srvrPubKey->u.ec.DEREncodedParams.len;
clntPubKey.u.ec.DEREncodedParams.data =
srvrPubKey->u.ec.DEREncodedParams.data;
rv = ssl3_ConsumeHandshakeVariable(ss, &clntPubKey.u.ec.publicValue,
1, &b, &length);
if (rv != SECSuccess) {
SEND_ALERT
return SECFailure; /* XXX Who sets the error code?? */
}
isTLS = (PRBool)(ss->ssl3.prSpec->version > SSL_LIBRARY_VERSION_3_0);
if (isTLS) target = CKM_TLS_MASTER_KEY_DERIVE_DH;
else target = CKM_SSL3_MASTER_KEY_DERIVE_DH;
/* Determine the PMS */
pms = PK11_PubDeriveWithKDF(srvrPrivKey, &clntPubKey, PR_FALSE, NULL, NULL,
CKM_ECDH1_DERIVE, target, CKA_DERIVE, 0,
CKD_NULL, NULL, NULL);
if (pms == NULL) {
/* last gasp. */
ssl_MapLowLevelError(SSL_ERROR_CLIENT_KEY_EXCHANGE_FAILURE);
return SECFailure;
}
rv = ssl3_InitPendingCipherSpec(ss, pms);
PK11_FreeSymKey(pms);
if (rv != SECSuccess) {
SEND_ALERT
return SECFailure; /* error code set by ssl3_InitPendingCipherSpec */
}
return SECSuccess;
}
/* find the "weakest link". Get strength of signature key and of sym key.
* choose curve for the weakest of those two.
*/
ECName
ssl3_GetCurveNameForServerSocket(sslSocket *ss)
{
SECKEYPublicKey * svrPublicKey = NULL;
ECName ec_curve = ec_noName;
int signatureKeyStrength = 521;
int requiredECCbits = ss->sec.secretKeyBits * 2;
int i;
if (ss->ssl3.hs.kea_def->kea == kea_ecdhe_ecdsa) {
svrPublicKey = SSL_GET_SERVER_PUBLIC_KEY(ss, kt_ecdh);
if (svrPublicKey)
ec_curve = params2ecName(&svrPublicKey->u.ec.DEREncodedParams);
if (!SSL_IS_CURVE_NEGOTIATED(ss, ec_curve)) {
PORT_SetError(SSL_ERROR_NO_CYPHER_OVERLAP);
return ec_noName;
}
signatureKeyStrength = curve2bits[ ec_curve ];
} else {
/* RSA is our signing cert */
int serverKeyStrengthInBits;
svrPublicKey = SSL_GET_SERVER_PUBLIC_KEY(ss, kt_rsa);
if (!svrPublicKey) {
PORT_SetError(SSL_ERROR_NO_CYPHER_OVERLAP);
return ec_noName;
}
/* currently strength in bytes */
serverKeyStrengthInBits = svrPublicKey->u.rsa.modulus.len;
if (svrPublicKey->u.rsa.modulus.data[0] == 0) {
serverKeyStrengthInBits--;
}
/* convert to strength in bits */
serverKeyStrengthInBits *= BPB;
if (serverKeyStrengthInBits <= 1024) {
signatureKeyStrength = 160;
} else if (serverKeyStrengthInBits <= 2048) {
signatureKeyStrength = 224;
} else if (serverKeyStrengthInBits <= 3072) {
signatureKeyStrength = 256;
} else if (serverKeyStrengthInBits <= 7168) {
signatureKeyStrength = 384;
} else {
signatureKeyStrength = 521;
}
}
if ( requiredECCbits > signatureKeyStrength )
requiredECCbits = signatureKeyStrength;
for ( i = 0; bits2curve[i].curve != ec_noName; i++) {
if (bits2curve[i].bits < requiredECCbits)
continue;
if (SSL_IS_CURVE_NEGOTIATED(ss, bits2curve[i].curve)) {
return bits2curve[i].curve;
}
}
PORT_SetError(SSL_ERROR_NO_CYPHER_OVERLAP);
return ec_noName;
}
/* function to clear out the lists */
static SECStatus
ssl3_ShutdownECDHECurves(void *appData, void *nssData)
{
int i;
ECDHEKeyPair *keyPair = &gECDHEKeyPairs[0];
for (i=0; i < ec_pastLastName; i++, keyPair++) {
if (keyPair->pair) {
ssl3_FreeKeyPair(keyPair->pair);
}
}
memset(gECDHEKeyPairs, 0, sizeof gECDHEKeyPairs);
return SECSuccess;
}
static PRStatus
ssl3_ECRegister(void)
{
SECStatus rv;
rv = NSS_RegisterShutdown(ssl3_ShutdownECDHECurves, gECDHEKeyPairs);
return (PRStatus)rv;
}
/* CallOnce function, called once for each named curve. */
static PRStatus
ssl3_CreateECDHEphemeralKeyPair(void * arg)
{
SECKEYPrivateKey * privKey = NULL;
SECKEYPublicKey * pubKey = NULL;
ssl3KeyPair * keyPair = NULL;
ECName ec_curve = (ECName)arg;
SECKEYECParams ecParams = { siBuffer, NULL, 0 };
PORT_Assert(gECDHEKeyPairs[ec_curve].pair == NULL);
/* ok, no one has generated a global key for this curve yet, do so */
if (ecName2params(NULL, ec_curve, &ecParams) != SECSuccess) {
return PR_FAILURE;
}
privKey = SECKEY_CreateECPrivateKey(&ecParams, &pubKey, NULL);
SECITEM_FreeItem(&ecParams, PR_FALSE);
if (!privKey || !pubKey || !(keyPair = ssl3_NewKeyPair(privKey, pubKey))) {
if (privKey) {
SECKEY_DestroyPrivateKey(privKey);
}
if (pubKey) {
SECKEY_DestroyPublicKey(pubKey);
}
ssl_MapLowLevelError(SEC_ERROR_KEYGEN_FAIL);
return PR_FAILURE;
}
gECDHEKeyPairs[ec_curve].pair = keyPair;
return PR_SUCCESS;
}
/*
* Creates the ephemeral public and private ECDH keys used by
* server in ECDHE_RSA and ECDHE_ECDSA handshakes.
* For now, the elliptic curve is chosen to be the same
* strength as the signing certificate (ECC or RSA).
* We need an API to specify the curve. This won't be a real
* issue until we further develop server-side support for ECC
* cipher suites.
*/
static SECStatus
ssl3_CreateECDHEphemeralKeys(sslSocket *ss, ECName ec_curve)
{
ssl3KeyPair * keyPair = NULL;
/* if there's no global key for this curve, make one. */
if (gECDHEKeyPairs[ec_curve].pair == NULL) {
PRStatus status;
status = PR_CallOnce(&gECDHEKeyPairs[ec_noName].once, ssl3_ECRegister);
if (status != PR_SUCCESS) {
return SECFailure;
}
status = PR_CallOnceWithArg(&gECDHEKeyPairs[ec_curve].once,
ssl3_CreateECDHEphemeralKeyPair,
(void *)ec_curve);
if (status != PR_SUCCESS) {
return SECFailure;
}
}
keyPair = gECDHEKeyPairs[ec_curve].pair;
PORT_Assert(keyPair != NULL);
if (!keyPair)
return SECFailure;
ss->ephemeralECDHKeyPair = ssl3_GetKeyPairRef(keyPair);
return SECSuccess;
}
SECStatus
ssl3_HandleECDHServerKeyExchange(sslSocket *ss, SSL3Opaque *b, PRUint32 length)
{
PRArenaPool * arena = NULL;
SECKEYPublicKey *peerKey = NULL;
PRBool isTLS;
SECStatus rv;
int errCode = SSL_ERROR_RX_MALFORMED_SERVER_KEY_EXCH;
SSL3AlertDescription desc = illegal_parameter;
SSL3Hashes hashes;
SECItem signature = {siBuffer, NULL, 0};
SECItem ec_params = {siBuffer, NULL, 0};
SECItem ec_point = {siBuffer, NULL, 0};
unsigned char paramBuf[3]; /* only for curve_type == named_curve */
isTLS = (PRBool)(ss->ssl3.prSpec->version > SSL_LIBRARY_VERSION_3_0);
/* XXX This works only for named curves, revisit this when
* we support generic curves.
*/
ec_params.len = sizeof paramBuf;
ec_params.data = paramBuf;
rv = ssl3_ConsumeHandshake(ss, ec_params.data, ec_params.len, &b, &length);
if (rv != SECSuccess) {
goto loser; /* malformed. */
}
/* Fail if the curve is not a named curve */
if ((ec_params.data[0] != ec_type_named) ||
(ec_params.data[1] != 0) ||
!supportedCurve(ec_params.data[2])) {
errCode = SEC_ERROR_UNSUPPORTED_ELLIPTIC_CURVE;
desc = handshake_failure;
goto alert_loser;
}
rv = ssl3_ConsumeHandshakeVariable(ss, &ec_point, 1, &b, &length);
if (rv != SECSuccess) {
goto loser; /* malformed. */
}
/* Fail if the ec point uses compressed representation */
if (ec_point.data[0] != EC_POINT_FORM_UNCOMPRESSED) {
errCode = SEC_ERROR_UNSUPPORTED_EC_POINT_FORM;
desc = handshake_failure;
goto alert_loser;
}
rv = ssl3_ConsumeHandshakeVariable(ss, &signature, 2, &b, &length);
if (rv != SECSuccess) {
goto loser; /* malformed. */
}
if (length != 0) {
if (isTLS)
desc = decode_error;
goto alert_loser; /* malformed. */
}
PRINT_BUF(60, (NULL, "Server EC params", ec_params.data,
ec_params.len));
PRINT_BUF(60, (NULL, "Server EC point", ec_point.data, ec_point.len));
/* failures after this point are not malformed handshakes. */
/* TLS: send decrypt_error if signature failed. */
desc = isTLS ? decrypt_error : handshake_failure;
/*
* check to make sure the hash is signed by right guy
*/
rv = ssl3_ComputeECDHKeyHash(ec_params, ec_point,
&ss->ssl3.hs.client_random,
&ss->ssl3.hs.server_random,
&hashes, ss->opt.bypassPKCS11);
if (rv != SECSuccess) {
errCode =
ssl_MapLowLevelError(SSL_ERROR_SERVER_KEY_EXCHANGE_FAILURE);
goto alert_loser;
}
rv = ssl3_VerifySignedHashes(&hashes, ss->sec.peerCert, &signature,
isTLS, ss->pkcs11PinArg);
if (rv != SECSuccess) {
errCode =
ssl_MapLowLevelError(SSL_ERROR_SERVER_KEY_EXCHANGE_FAILURE);
goto alert_loser;
}
arena = PORT_NewArena(DER_DEFAULT_CHUNKSIZE);
if (arena == NULL) {
goto no_memory;
}
ss->sec.peerKey = peerKey = PORT_ArenaZNew(arena, SECKEYPublicKey);
if (peerKey == NULL) {
goto no_memory;
}
peerKey->arena = arena;
peerKey->keyType = ecKey;
/* set up EC parameters in peerKey */
if (ecName2params(arena, ec_params.data[2],
&peerKey->u.ec.DEREncodedParams) != SECSuccess) {
/* we should never get here since we already
* checked that we are dealing with a supported curve
*/
errCode = SEC_ERROR_UNSUPPORTED_ELLIPTIC_CURVE;
goto alert_loser;
}
/* copy publicValue in peerKey */
if (SECITEM_CopyItem(arena, &peerKey->u.ec.publicValue, &ec_point))
{
PORT_FreeArena(arena, PR_FALSE);
goto no_memory;
}
peerKey->pkcs11Slot = NULL;
peerKey->pkcs11ID = CK_INVALID_HANDLE;
ss->sec.peerKey = peerKey;
ss->ssl3.hs.ws = wait_cert_request;
return SECSuccess;
alert_loser:
(void)SSL3_SendAlert(ss, alert_fatal, desc);
loser:
PORT_SetError( errCode );
return SECFailure;
no_memory: /* no-memory error has already been set. */
ssl_MapLowLevelError(SSL_ERROR_SERVER_KEY_EXCHANGE_FAILURE);
return SECFailure;
}
SECStatus
ssl3_SendECDHServerKeyExchange(sslSocket *ss)
{
const ssl3KEADef * kea_def = ss->ssl3.hs.kea_def;
SECStatus rv = SECFailure;
int length;
PRBool isTLS;
SECItem signed_hash = {siBuffer, NULL, 0};
SSL3Hashes hashes;
SECKEYPublicKey * ecdhePub;
SECItem ec_params = {siBuffer, NULL, 0};
unsigned char paramBuf[3];
ECName curve;
SSL3KEAType certIndex;
/* Generate ephemeral ECDH key pair and send the public key */
curve = ssl3_GetCurveNameForServerSocket(ss);
if (curve == ec_noName) {
goto loser;
}
rv = ssl3_CreateECDHEphemeralKeys(ss, curve);
if (rv != SECSuccess) {
goto loser; /* err set by AppendHandshake. */
}
ecdhePub = ss->ephemeralECDHKeyPair->pubKey;
PORT_Assert(ecdhePub != NULL);
if (!ecdhePub) {
PORT_SetError(SSL_ERROR_SERVER_KEY_EXCHANGE_FAILURE);
return SECFailure;
}
ec_params.len = sizeof paramBuf;
ec_params.data = paramBuf;
curve = params2ecName(&ecdhePub->u.ec.DEREncodedParams);
if (curve != ec_noName) {
ec_params.data[0] = ec_type_named;
ec_params.data[1] = 0x00;
ec_params.data[2] = curve;
} else {
PORT_SetError(SEC_ERROR_UNSUPPORTED_ELLIPTIC_CURVE);
goto loser;
}
rv = ssl3_ComputeECDHKeyHash(ec_params, ecdhePub->u.ec.publicValue,
&ss->ssl3.hs.client_random,
&ss->ssl3.hs.server_random,
&hashes, ss->opt.bypassPKCS11);
if (rv != SECSuccess) {
ssl_MapLowLevelError(SSL_ERROR_SERVER_KEY_EXCHANGE_FAILURE);
goto loser;
}
isTLS = (PRBool)(ss->ssl3.pwSpec->version > SSL_LIBRARY_VERSION_3_0);
/* XXX SSLKEAType isn't really a good choice for
* indexing certificates but that's all we have
* for now.
*/
if (kea_def->kea == kea_ecdhe_rsa)
certIndex = kt_rsa;
else /* kea_def->kea == kea_ecdhe_ecdsa */
certIndex = kt_ecdh;
rv = ssl3_SignHashes(&hashes, ss->serverCerts[certIndex].SERVERKEY,
&signed_hash, isTLS);
if (rv != SECSuccess) {
goto loser; /* ssl3_SignHashes has set err. */
}
if (signed_hash.data == NULL) {
/* how can this happen and rv == SECSuccess ?? */
PORT_SetError(SSL_ERROR_SERVER_KEY_EXCHANGE_FAILURE);
goto loser;
}
length = ec_params.len +
1 + ecdhePub->u.ec.publicValue.len +
2 + signed_hash.len;
rv = ssl3_AppendHandshakeHeader(ss, server_key_exchange, length);
if (rv != SECSuccess) {
goto loser; /* err set by AppendHandshake. */
}
rv = ssl3_AppendHandshake(ss, ec_params.data, ec_params.len);
if (rv != SECSuccess) {
goto loser; /* err set by AppendHandshake. */
}
rv = ssl3_AppendHandshakeVariable(ss, ecdhePub->u.ec.publicValue.data,
ecdhePub->u.ec.publicValue.len, 1);
if (rv != SECSuccess) {
goto loser; /* err set by AppendHandshake. */
}
rv = ssl3_AppendHandshakeVariable(ss, signed_hash.data,
signed_hash.len, 2);
if (rv != SECSuccess) {
goto loser; /* err set by AppendHandshake. */
}
PORT_Free(signed_hash.data);
return SECSuccess;
loser:
if (signed_hash.data != NULL)
PORT_Free(signed_hash.data);
return SECFailure;
}
/* Lists of ECC cipher suites for searching and disabling. */
static const ssl3CipherSuite ecdh_suites[] = {
TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA,
TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA,
TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA,
TLS_ECDH_ECDSA_WITH_NULL_SHA,
TLS_ECDH_ECDSA_WITH_RC4_128_SHA,
TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA,
TLS_ECDH_RSA_WITH_AES_128_CBC_SHA,
TLS_ECDH_RSA_WITH_AES_256_CBC_SHA,
TLS_ECDH_RSA_WITH_NULL_SHA,
TLS_ECDH_RSA_WITH_RC4_128_SHA,
0 /* end of list marker */
};
static const ssl3CipherSuite ecdh_ecdsa_suites[] = {
TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA,
TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA,
TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA,
TLS_ECDH_ECDSA_WITH_NULL_SHA,
TLS_ECDH_ECDSA_WITH_RC4_128_SHA,
0 /* end of list marker */
};
static const ssl3CipherSuite ecdh_rsa_suites[] = {
TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA,
TLS_ECDH_RSA_WITH_AES_128_CBC_SHA,
TLS_ECDH_RSA_WITH_AES_256_CBC_SHA,
TLS_ECDH_RSA_WITH_NULL_SHA,
TLS_ECDH_RSA_WITH_RC4_128_SHA,
0 /* end of list marker */
};
static const ssl3CipherSuite ecdhe_ecdsa_suites[] = {
TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA,
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
TLS_ECDHE_ECDSA_WITH_NULL_SHA,
TLS_ECDHE_ECDSA_WITH_RC4_128_SHA,
0 /* end of list marker */
};
static const ssl3CipherSuite ecdhe_rsa_suites[] = {
TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA,
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,
TLS_ECDHE_RSA_WITH_NULL_SHA,
TLS_ECDHE_RSA_WITH_RC4_128_SHA,
0 /* end of list marker */
};
/* List of all ECC cipher suites */
static const ssl3CipherSuite ecSuites[] = {
TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA,
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
TLS_ECDHE_ECDSA_WITH_NULL_SHA,
TLS_ECDHE_ECDSA_WITH_RC4_128_SHA,
TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA,
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,
TLS_ECDHE_RSA_WITH_NULL_SHA,
TLS_ECDHE_RSA_WITH_RC4_128_SHA,
TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA,
TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA,
TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA,
TLS_ECDH_ECDSA_WITH_NULL_SHA,
TLS_ECDH_ECDSA_WITH_RC4_128_SHA,
TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA,
TLS_ECDH_RSA_WITH_AES_128_CBC_SHA,
TLS_ECDH_RSA_WITH_AES_256_CBC_SHA,
TLS_ECDH_RSA_WITH_NULL_SHA,
TLS_ECDH_RSA_WITH_RC4_128_SHA,
0 /* end of list marker */
};
/* On this socket, Disable the ECC cipher suites in the argument's list */
SECStatus
ssl3_DisableECCSuites(sslSocket * ss, const ssl3CipherSuite * suite)
{
if (!suite)
suite = ecSuites;
for (; *suite; ++suite) {
SECStatus rv = ssl3_CipherPrefSet(ss, *suite, PR_FALSE);
PORT_Assert(rv == SECSuccess); /* else is coding error */
}
return SECSuccess;
}
/* Look at the server certs configured on this socket, and disable any
* ECC cipher suites that are not supported by those certs.
*/
void
ssl3_FilterECCipherSuitesByServerCerts(sslSocket * ss)
{
CERTCertificate * svrCert;
svrCert = ss->serverCerts[kt_rsa].serverCert;
if (!svrCert) {
ssl3_DisableECCSuites(ss, ecdhe_rsa_suites);
}
svrCert = ss->serverCerts[kt_ecdh].serverCert;
if (!svrCert) {
ssl3_DisableECCSuites(ss, ecdh_suites);
ssl3_DisableECCSuites(ss, ecdhe_ecdsa_suites);
} else {
SECOidTag sigTag = SECOID_GetAlgorithmTag(&svrCert->signature);
switch (sigTag) {
case SEC_OID_PKCS1_RSA_ENCRYPTION:
case SEC_OID_PKCS1_MD2_WITH_RSA_ENCRYPTION:
case SEC_OID_PKCS1_MD4_WITH_RSA_ENCRYPTION:
case SEC_OID_PKCS1_MD5_WITH_RSA_ENCRYPTION:
case SEC_OID_PKCS1_SHA1_WITH_RSA_ENCRYPTION:
case SEC_OID_PKCS1_SHA256_WITH_RSA_ENCRYPTION:
case SEC_OID_PKCS1_SHA384_WITH_RSA_ENCRYPTION:
case SEC_OID_PKCS1_SHA512_WITH_RSA_ENCRYPTION:
ssl3_DisableECCSuites(ss, ecdh_ecdsa_suites);
break;
case SEC_OID_ANSIX962_ECDSA_SHA1_SIGNATURE:
case SEC_OID_ANSIX962_ECDSA_SHA224_SIGNATURE:
case SEC_OID_ANSIX962_ECDSA_SHA256_SIGNATURE:
case SEC_OID_ANSIX962_ECDSA_SHA384_SIGNATURE:
case SEC_OID_ANSIX962_ECDSA_SHA512_SIGNATURE:
case SEC_OID_ANSIX962_ECDSA_SIGNATURE_RECOMMENDED_DIGEST:
case SEC_OID_ANSIX962_ECDSA_SIGNATURE_SPECIFIED_DIGEST:
ssl3_DisableECCSuites(ss, ecdh_rsa_suites);
break;
default:
ssl3_DisableECCSuites(ss, ecdh_suites);
break;
}
}
}
/* Ask: is ANY ECC cipher suite enabled on this socket? */
/* Order(N^2). Yuk. Also, this ignores export policy. */
PRBool
ssl3_IsECCEnabled(sslSocket * ss)
{
const ssl3CipherSuite * suite;
for (suite = ecSuites; *suite; ++suite) {
PRBool enabled = PR_FALSE;
SECStatus rv = ssl3_CipherPrefGet(ss, *suite, &enabled);
PORT_Assert(rv == SECSuccess); /* else is coding error */
if (rv == SECSuccess && enabled)
return PR_TRUE;
}
return PR_FALSE;
}
#define BE(n) 0, n
#ifndef NSS_ECC_MORE_THAN_SUITE_B
/* Prefabricated TLS client hello extension, Elliptic Curves List,
* offers only 3 curves, the Suite B curves, 23-35
*/
static const PRUint8 EClist[12] = {
BE(10), /* Extension type */
BE( 8), /* octets that follow ( 3 pairs + 1 length pair) */
BE( 6), /* octets that follow ( 3 pairs) */
BE(23), BE(24), BE(25)
};
#else
/* Prefabricated TLS client hello extension, Elliptic Curves List,
* offers curves 1-25.
*/
static const PRUint8 EClist[56] = {
BE(10), /* Extension type */
BE(52), /* octets that follow (25 pairs + 1 length pair) */
BE(50), /* octets that follow (25 pairs) */
BE( 1), BE( 2), BE( 3), BE( 4), BE( 5), BE( 6), BE( 7),
BE( 8), BE( 9), BE(10), BE(11), BE(12), BE(13), BE(14), BE(15),
BE(16), BE(17), BE(18), BE(19), BE(20), BE(21), BE(22), BE(23),
BE(24), BE(25)
};
#endif
static const PRUint8 ECPtFmt[6] = {
BE(11), /* Extension type */
BE( 2), /* octets that follow */
1, /* octets that follow */
0 /* uncompressed type only */
};
/* Send our "canned" (precompiled) Supported Elliptic Curves extension,
* which says that we support all TLS-defined named curves.
*/
PRInt32
ssl3_SendSupportedEllipticCurvesExtension(
sslSocket * ss,
PRBool append,
PRUint32 maxBytes)
{
if (!ss || !ssl3_IsECCEnabled(ss))
return 0;
if (append && maxBytes >= (sizeof EClist)) {
SECStatus rv = ssl3_AppendHandshake(ss, EClist, (sizeof EClist));
}
return (sizeof EClist);
}
/* Send our "canned" (precompiled) Supported Point Formats extension,
* which says that we only support uncompressed points.
*/
PRInt32
ssl3_SendSupportedPointFormatsExtension(
sslSocket * ss,
PRBool append,
PRUint32 maxBytes)
{
if (!ss || !ssl3_IsECCEnabled(ss))
return 0;
if (append && maxBytes >= (sizeof ECPtFmt)) {
SECStatus rv = ssl3_AppendHandshake(ss, ECPtFmt, (sizeof ECPtFmt));
}
return (sizeof ECPtFmt);
}
/* Just make sure that the remote client supports uncompressed points,
* Since that is all we support. Disable ECC cipher suites if it doesn't.
*/
static SECStatus
ssl3_HandleSupportedPointFormatsExtension(sslSocket * ss, PRUint16 ex_type,
SECItem *data)
{
int i;
if (data->len < 2 || data->len > 255 || !data->data ||
data->len != (unsigned int)data->data[0] + 1) {
/* malformed */
goto loser;
}
for (i = data->len; --i > 0; ) {
if (data->data[i] == 0) {
/* indicate that we should send a reply */
SECStatus rv;
rv = ssl3_RegisterServerHelloExtensionSender(ss, ex_type,
&ssl3_SendSupportedPointFormatsExtension);
return rv;
}
}
loser:
/* evil client doesn't support uncompressed */
ssl3_DisableECCSuites(ss, ecSuites);
return SECFailure;
}
#define SSL3_GET_SERVER_PUBLICKEY(sock, type) \
(ss->serverCerts[type].serverKeyPair ? \
ss->serverCerts[type].serverKeyPair->pubKey : NULL)
/* Extract the TLS curve name for the public key in our EC server cert. */
ECName ssl3_GetSvrCertCurveName(sslSocket *ss)
{
SECKEYPublicKey *srvPublicKey;
ECName ec_curve = ec_noName;
srvPublicKey = SSL3_GET_SERVER_PUBLICKEY(ss, kt_ecdh);
if (srvPublicKey) {
ec_curve = params2ecName(&srvPublicKey->u.ec.DEREncodedParams);
}
return ec_curve;
}
/* Ensure that the curve in our server cert is one of the ones suppored
* by the remote client, and disable all ECC cipher suites if not.
*/
static SECStatus
ssl3_HandleSupportedEllipticCurvesExtension(sslSocket * ss, PRUint16 ex_type,
SECItem *data)
{
PRInt32 list_len;
PRUint32 peerCurves = 0;
PRUint32 mutualCurves = 0;
PRUint16 svrCertCurveName;
if (!data->data || data->len < 4 || data->len > 65535)
goto loser;
/* get the length of elliptic_curve_list */
list_len = ssl3_ConsumeHandshakeNumber(ss, 2, &data->data, &data->len);
if (list_len < 0 || data->len != list_len || (data->len % 2) != 0) {
/* malformed */
goto loser;
}
/* build bit vector of peer's supported curve names */
while (data->len) {
PRInt32 curve_name =
ssl3_ConsumeHandshakeNumber(ss, 2, &data->data, &data->len);
if (curve_name > ec_noName && curve_name < ec_pastLastName) {
peerCurves |= (1U << curve_name);
}
}
/* What curves do we support in common? */
mutualCurves = ss->ssl3.hs.negotiatedECCurves &= peerCurves;
if (!mutualCurves) { /* no mutually supported EC Curves */
goto loser;
}
/* if our ECC cert doesn't use one of these supported curves,
* disable ECC cipher suites that require an ECC cert.
*/
svrCertCurveName = ssl3_GetSvrCertCurveName(ss);
if (svrCertCurveName != ec_noName &&
(mutualCurves & (1U << svrCertCurveName)) != 0) {
return SECSuccess;
}
/* Our EC cert doesn't contain a mutually supported curve.
* Disable all ECC cipher suites that require an EC cert
*/
ssl3_DisableECCSuites(ss, ecdh_ecdsa_suites);
ssl3_DisableECCSuites(ss, ecdhe_ecdsa_suites);
return SECFailure;
loser:
/* no common curve supported */
ssl3_DisableECCSuites(ss, ecSuites);
return SECFailure;
}
#endif /* NSS_ENABLE_ECC */
/* Format an SNI extension, using the name from the socket's URL,
* unless that name is a dotted decimal string.
*/
PRInt32
ssl3_SendServerNameIndicationExtension(
sslSocket * ss,
PRBool append,
PRUint32 maxBytes)
{
PRUint32 len, span;
/* must have a hostname */
if (!ss || !ss->url || !ss->url[0])
return 0;
/* must have at lest one character other than [0-9\.] */
len = PORT_Strlen(ss->url);
span = strspn(ss->url, "0123456789.");
if (len == span) {
/* is a dotted decimal IP address */
return 0;
}
if (append && maxBytes >= len + 9) {
SECStatus rv;
/* extension_type */
rv = ssl3_AppendHandshakeNumber(ss, 0, 2);
if (rv != SECSuccess) return 0;
/* length of extension_data */
rv = ssl3_AppendHandshakeNumber(ss, len + 5, 2);
if (rv != SECSuccess) return 0;
/* length of server_name_list */
rv = ssl3_AppendHandshakeNumber(ss, len + 3, 2);
if (rv != SECSuccess) return 0;
/* Name Type (host_name) */
rv = ssl3_AppendHandshake(ss, "\0", 1);
if (rv != SECSuccess) return 0;
/* HostName (length and value) */
rv = ssl3_AppendHandshakeVariable(ss, ss->url, len, 2);
if (rv != SECSuccess) return 0;
}
return len + 9;
}
/* handle an incoming SNI extension, by ignoring it. */
SECStatus
ssl3_HandleServerNameIndicationExtension(sslSocket * ss, PRUint16 ex_type,
SECItem *data)
{
/* For now, we ignore this, as if we didn't understand it. :-) */
return SECSuccess;
}
/* Table of handlers for received TLS hello extensions, one per extension.
* In the second generation, this table will be dynamic, and functions
* will be registered here.
*/
static const ssl3HelloExtensionHandler handlers[] = {
{ 0, &ssl3_HandleServerNameIndicationExtension },
#ifdef NSS_ENABLE_ECC
{ 10, &ssl3_HandleSupportedEllipticCurvesExtension },
{ 11, &ssl3_HandleSupportedPointFormatsExtension },
#endif
{ -1, NULL }
};
/* Table of functions to format TLS hello extensions, one per extension.
* This static table is for the formatting of client hello extensions.
* The server's table of hello senders is dynamic, in the socket struct,
* and sender functions are registered there.
*/
static const
ssl3HelloExtensionSender clientHelloSenders[MAX_EXTENSION_SENDERS] = {
{ 0, &ssl3_SendServerNameIndicationExtension },
#ifdef NSS_ENABLE_ECC
{ 10, &ssl3_SendSupportedEllipticCurvesExtension },
{ 11, &ssl3_SendSupportedPointFormatsExtension },
#else
{ -1, NULL }
#endif
};
/* go through hello extensions in buffer "b".
* For each one, find the extension handler in the table above, and
* if present, invoke that handler.
* ignore any extensions with unknown extension types.
*/
SECStatus
ssl3_HandleClientHelloExtensions(sslSocket *ss,
SSL3Opaque **b,
PRUint32 *length)
{
while (*length) {
const ssl3HelloExtensionHandler * handler;
SECStatus rv;
PRInt32 extension_type;
SECItem extension_data;
/* Get the extension's type field */
extension_type = ssl3_ConsumeHandshakeNumber(ss, 2, b, length);
if (extension_type < 0) /* failure to decode extension_type */
return SECFailure; /* alert already sent */
/* get the data for this extension, so we can pass it or skip it. */
rv = ssl3_ConsumeHandshakeVariable(ss, &extension_data, 2, b, length);
if (rv != SECSuccess)
return rv;
/* find extension_type in table of Client Hello Extension Handlers */
for (handler = handlers; handler->ex_type >= 0; handler++) {
if (handler->ex_type == extension_type)
break;
}
/* if found, Call this handler */
if (handler->ex_type == extension_type) {
rv = (*handler->ex_handler)(ss, (PRUint16)extension_type,
&extension_data);
/* Ignore this result */
/* Essentially, treat all bad extensions as unrecognized types. */
}
}
return SECSuccess;
}
/* Add a callback function to the table of senders of server hello extensions.
*/
SECStatus
ssl3_RegisterServerHelloExtensionSender(sslSocket *ss, PRUint16 ex_type,
ssl3HelloExtensionSenderFunc cb)
{
int i;
ssl3HelloExtensionSender *sender = &ss->serverExtensionSenders[0];
for (i = 0; i < MAX_EXTENSION_SENDERS; ++i, ++sender) {
if (!sender->ex_sender) {
sender->ex_type = ex_type;
sender->ex_sender = cb;
return SECSuccess;
}
/* detect duplicate senders */
PORT_Assert(sender->ex_type != ex_type);
if (sender->ex_type == ex_type) {
/* duplicate */
break;
}
}
PORT_Assert(i < MAX_EXTENSION_SENDERS); /* table needs to grow */
PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
return SECFailure;
}
/* call each of the extension senders and return the accumulated length */
PRInt32
ssl3_CallHelloExtensionSenders(sslSocket *ss, PRBool append, PRUint32 maxBytes,
const ssl3HelloExtensionSender *sender)
{
PRInt32 total_exten_len = 0;
int i;
if (!sender)
sender = &clientHelloSenders[0];
for (i = 0; i < MAX_EXTENSION_SENDERS; ++i, ++sender) {
if (sender->ex_sender) {
PRInt32 extLen = (*sender->ex_sender)(ss, append, maxBytes);
if (extLen < 0)
return -1;
maxBytes -= extLen;
total_exten_len += extLen;
}
}
return total_exten_len;
}
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