SecureTransport/sslCert.cpp

   1 /*
   2  * Copyright (c) 2000-2001 Apple Computer, Inc. All Rights Reserved.
   3  *
   4  * The contents of this file constitute Original Code as defined in and are
   5  * subject to the Apple Public Source License Version 1.2 (the 'License').
   6  * You may not use this file except in compliance with the License. Please obtain
   7  * a copy of the License at http://www.apple.com/publicsource and read it before
   8  * using this file.
   9  *
  10  * This Original Code and all software distributed under the License are
  11  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS
  12  * OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, INCLUDING WITHOUT
  13  * LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
  14  * PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see the License for the
  15  * specific language governing rights and limitations under the License.
  16  */
  17
  18
  19 /*
  20         File:           sslCert.cpp
  21
  22         Contains:       certificate request/verify messages
  23
  24         Written by:     Doug Mitchell
  25
  26         Copyright: (c) 1999 by Apple Computer, Inc., all rights reserved.
  27
  28 */
  29 #include "sslContext.h"
  30 #include "sslHandshake.h"
  31 #include "sslMemory.h"
  32 #include "sslAlertMessage.h"
  33 #include "sslDebug.h"
  34 #include "sslUtils.h"
  35 #include "sslDigests.h"
  36 #include "appleCdsa.h"
  37
  38 #include <string.h>
  39 #include <assert.h>
  40
  41 OSStatus
  42 SSLEncodeCertificate(SSLRecord &certificate, SSLContext *ctx)
  43 {   OSStatus        err;
  44     UInt32          totalLength;
  45     int             i, j, certCount;
  46     UInt8           *charPtr;
  47     SSLCertificate  *cert;
  48
  49     /*
  50          * TBD: for client side, match Match DER-encoded acceptable DN list
  51          * (ctx->acceptableDNList) to one of our certs. For now we just send
  52          * what we have since we don't support multiple certs.
  53          *
  54          * Note this can be called with localCert==0 for client seide in TLS1;
  55          * in that case we send an empty cert msg.
  56          */
  57     cert = ctx->localCert;
  58         assert((ctx->negProtocolVersion == SSL_Version_3_0) ||
  59                    (ctx->negProtocolVersion == TLS_Version_1_0));
  60         assert((cert != NULL) || (ctx->negProtocolVersion == TLS_Version_1_0));
  61     totalLength = 0;
  62     certCount = 0;
  63     while (cert)
  64     {   totalLength += 3 + cert->derCert.length;    /* 3 for encoded length field */
  65         ++certCount;
  66         cert = cert->next;
  67     }
  68
  69     certificate.contentType = SSL_RecordTypeHandshake;
  70     certificate.protocolVersion = ctx->negProtocolVersion;
  71     if ((err = SSLAllocBuffer(certificate.contents, totalLength + 7, ctx)) != 0)
  72         return err;
  73
  74     charPtr = certificate.contents.data;
  75     *charPtr++ = SSL_HdskCert;
  76     charPtr = SSLEncodeInt(charPtr, totalLength+3, 3);    /* Handshake message length */
  77     charPtr = SSLEncodeInt(charPtr, totalLength, 3);      /* Vector length */
  78
  79     /* Root cert is first in the linked list, but has to go last,
  80          * so walk list backwards */
  81     for (i = 0; i < certCount; ++i)
  82     {   cert = ctx->localCert;
  83         for (j = i+1; j < certCount; ++j)
  84             cert = cert->next;
  85         charPtr = SSLEncodeInt(charPtr, cert->derCert.length, 3);
  86         memcpy(charPtr, cert->derCert.data, cert->derCert.length);
  87         charPtr += cert->derCert.length;
  88     }
  89
  90     assert(charPtr == certificate.contents.data + certificate.contents.length);
  91
  92     if ((ctx->protocolSide == SSL_ClientSide) && (ctx->localCert)) {
  93                 /* this tells us to send a CertificateVerify msg after the
  94                  * client key exchange. We skip the cert vfy if we just
  95                  * sent an empty cert msg (i.e., we were asked for a cert
  96                  * but we don't have one). */
  97         ctx->certSent = 1;
  98                 assert(ctx->clientCertState == kSSLClientCertRequested);
  99                 assert(ctx->certRequested);
 100                 ctx->clientCertState = kSSLClientCertSent;
 101         }
 102     return noErr;
 103 }
 104
 105 OSStatus
 106 SSLProcessCertificate(SSLBuffer message, SSLContext *ctx)
 107 {   OSStatus        err;
 108     UInt32          listLen, certLen;
 109     UInt8           *p;
 110     SSLCertificate  *cert;
 111
 112     p = message.data;
 113     listLen = SSLDecodeInt(p,3);
 114     p += 3;
 115     if (listLen + 3 != message.length) {
 116         sslErrorLog("SSLProcessCertificate: length decode error 1\n");
 117         return errSSLProtocol;
 118     }
 119
 120     while (listLen > 0)
 121     {   certLen = SSLDecodeInt(p,3);
 122         p += 3;
 123         if (listLen < certLen + 3) {
 124                 sslErrorLog("SSLProcessCertificate: length decode error 2\n");
 125             return errSSLProtocol;
 126         }
 127                 cert = (SSLCertificate *)sslMalloc(sizeof(SSLCertificate));
 128                 if(cert == NULL) {
 129                         return memFullErr;
 130                 }
 131         if ((err = SSLAllocBuffer(cert->derCert, certLen, ctx)) != 0)
 132         {   sslFree(cert);
 133             return err;
 134         }
 135         memcpy(cert->derCert.data, p, certLen);
 136         p += certLen;
 137         cert->next = ctx->peerCert;     /* Insert backwards; root cert
 138                                                                                  * will be first in linked list */
 139         ctx->peerCert = cert;
 140         listLen -= 3+certLen;
 141     }
 142     assert(p == message.data + message.length && listLen == 0);
 143
 144     if (ctx->peerCert == 0) {
 145                 /* this *might* be OK... */
 146                 if((ctx->protocolSide == SSL_ServerSide) &&
 147                    (ctx->clientAuth != kAlwaysAuthenticate)) {
 148                         /*
 149                          * we tried to authenticate, client doesn't have a cert, and
 150                          * app doesn't require it. OK.
 151                          */
 152                         return noErr;
 153                 }
 154                 else {
 155                         AlertDescription desc;
 156                         if(ctx->negProtocolVersion == SSL_Version_3_0) {
 157                                 /* this one's for SSL3 only */
 158                                 desc = SSL_AlertBadCert;
 159                         }
 160                         else {
 161                                 desc = SSL_AlertCertUnknown;
 162                         }
 163                         SSLFatalSessionAlert(desc, ctx);
 164                         return errSSLXCertChainInvalid;
 165                 }
 166     }
 167     if((err = sslVerifyCertChain(ctx, *ctx->peerCert)) != 0) {
 168                 AlertDescription desc;
 169                 switch(err) {
 170                         case errSSLUnknownRootCert:
 171                         case errSSLNoRootCert:
 172                                 desc = SSL_AlertUnknownCA;
 173                                 break;
 174                         case errSSLCertExpired:
 175                         case errSSLCertNotYetValid:
 176                                 desc = SSL_AlertCertExpired;
 177                                 break;
 178                         case errSSLXCertChainInvalid:
 179                         default:
 180                                 desc = SSL_AlertCertUnknown;
 181                                 break;
 182                 }
 183                 SSLFatalSessionAlert(desc, ctx);
 184         return err;
 185         }
 186
 187         /* peer's certificate is the last one in the chain */
 188     cert = ctx->peerCert;
 189     while (cert->next != 0)
 190         cert = cert->next;
 191         /* Convert its public key to CDSA format */
 192     if ((err = sslPubKeyFromCert(ctx,
 193         cert->derCert,
 194         &ctx->peerPubKey,
 195         &ctx->peerPubKeyCsp)) != 0)
 196         return err;
 197
 198     return noErr;
 199 }
 200
 201 OSStatus
 202 SSLEncodeCertificateRequest(SSLRecord &request, SSLContext *ctx)
 203 {
 204         OSStatus    err;
 205     UInt32      dnListLen, msgLen;
 206     UInt8       *charPtr;
 207     DNListElem  *dn;
 208
 209         assert(ctx->protocolSide == SSL_ServerSide);
 210         dnListLen = 0;
 211     dn = ctx->acceptableDNList;
 212     while (dn)
 213     {   dnListLen += 2 + dn->derDN.length;
 214         dn = dn->next;
 215     }
 216     msgLen = 1 + 1 + 2 + dnListLen;
 217
 218     request.contentType = SSL_RecordTypeHandshake;
 219         assert((ctx->negProtocolVersion == SSL_Version_3_0) ||
 220                    (ctx->negProtocolVersion == TLS_Version_1_0));
 221     request.protocolVersion = ctx->negProtocolVersion;
 222     if ((err = SSLAllocBuffer(request.contents, msgLen + 4, ctx)) != 0)
 223         return err;
 224
 225     charPtr = request.contents.data;
 226     *charPtr++ = SSL_HdskCertRequest;
 227     charPtr = SSLEncodeInt(charPtr, msgLen, 3);
 228
 229     *charPtr++ = 1;        /* one cert type */
 230     *charPtr++ = 1;        /* RSA-sign type */
 231     charPtr = SSLEncodeInt(charPtr, dnListLen, 2);
 232     dn = ctx->acceptableDNList;
 233     while (dn)
 234     {   charPtr = SSLEncodeInt(charPtr, dn->derDN.length, 2);
 235         memcpy(charPtr, dn->derDN.data, dn->derDN.length);
 236         charPtr += dn->derDN.length;
 237         dn = dn->next;
 238     }
 239
 240     assert(charPtr == request.contents.data + request.contents.length);
 241     return noErr;
 242 }
 243
 244 OSStatus
 245 SSLProcessCertificateRequest(SSLBuffer message, SSLContext *ctx)
 246 {
 247     unsigned        i;
 248     unsigned        typeCount;
 249     UInt8           *charPtr;
 250
 251         /*
 252          * Cert request only happens in during client authentication, which
 253          * we don't do. We will however take this handshake msg and do
 254          * nothing with the enclosed DNList. We'll send a client cert
 255          * if we have one but we don't do any DNList compare.
 256          */
 257     if (message.length < 3) {
 258         sslErrorLog("SSLProcessCertificateRequest: length decode error 1\n");
 259         return errSSLProtocol;
 260     }
 261     charPtr = message.data;
 262     typeCount = *charPtr++;
 263     if (typeCount < 1 || message.length < 3 + typeCount) {
 264         sslErrorLog("SSLProcessCertificateRequest: length decode error 2\n");
 265         return errSSLProtocol;
 266     }
 267     for (i = 0; i < typeCount; i++)
 268     {   if (*charPtr++ == 1)
 269             ctx->x509Requested = 1;
 270     }
 271
 272         #if             0
 273         /* FIXME - currently untested  */
 274     unsigned    dnListLen;
 275         unsigned        dnLen;
 276     SSLBuffer   dnBuf;
 277     DNListElem  *dn;
 278         OSStatus        err;
 279
 280     dnListLen = SSLDecodeInt(charPtr, 2);
 281     charPtr += 2;
 282     if (message.length != 3 + typeCount + dnListLen) {
 283         sslErrorLog("SSLProcessCertificateRequest: length decode error 3\n");
 284         return errSSLProtocol;
 285         }
 286     while (dnListLen > 0)
 287     {   if (dnListLen < 2) {
 288                 sslErrorLog("SSLProcessCertificateRequest: dnListLen error 1\n");
 289             return errSSLProtocol;
 290         }
 291         dnLen = SSLDecodeInt(charPtr, 2);
 292         charPtr += 2;
 293         if (dnListLen < 2 + dnLen) {
 294                 sslErrorLog("SSLProcessCertificateRequest: dnListLen error 2\n");
 295                 return errSSLProtocol;
 296         }
 297         if ((err = SSLAllocBuffer(dnBuf, sizeof(DNListElem), ctx)) != 0)
 298             return err;
 299         dn = (DNListElem*)dnBuf.data;
 300         if ((err = SSLAllocBuffer(dn->derDN, dnLen, ctx)) != 0)
 301         {   SSLFreeBuffer(dnBuf, ctx);
 302             return err;
 303         }
 304         memcpy(dn->derDN.data, charPtr, dnLen);
 305         charPtr += dnLen;
 306         dn->next = ctx->acceptableDNList;
 307         ctx->acceptableDNList = dn;
 308         dnListLen -= 2 + dnLen;
 309     }
 310
 311     assert(charPtr == message.data + message.length);
 312         #endif  /* untested client-side authentication */
 313
 314     return noErr;
 315 }
 316
 317 OSStatus
 318 SSLEncodeCertificateVerify(SSLRecord &certVerify, SSLContext *ctx)
 319 {   OSStatus        err;
 320     UInt8           hashData[36];
 321     SSLBuffer       hashDataBuf, shaMsgState, md5MsgState;
 322     UInt32          len;
 323     UInt32                  outputLen;
 324
 325     certVerify.contents.data = 0;
 326     hashDataBuf.data = hashData;
 327     hashDataBuf.length = 36;
 328
 329     if ((err = CloneHashState(SSLHashSHA1, ctx->shaState, shaMsgState, ctx)) != 0)
 330         goto fail;
 331     if ((err = CloneHashState(SSLHashMD5, ctx->md5State, md5MsgState, ctx)) != 0)
 332         goto fail;
 333         assert(ctx->sslTslCalls != NULL);
 334     if ((err = ctx->sslTslCalls->computeCertVfyMac(ctx, hashDataBuf,
 335                         shaMsgState, md5MsgState)) != 0)
 336         goto fail;
 337
 338         assert(ctx->signingPrivKey != NULL);
 339         len = sslKeyLengthInBytes(ctx->signingPrivKey);
 340
 341     certVerify.contentType = SSL_RecordTypeHandshake;
 342         assert((ctx->negProtocolVersion == SSL_Version_3_0) ||
 343                    (ctx->negProtocolVersion == TLS_Version_1_0));
 344     certVerify.protocolVersion = ctx->negProtocolVersion;
 345     if ((err = SSLAllocBuffer(certVerify.contents, len + 6, ctx)) != 0)
 346         goto fail;
 347
 348     certVerify.contents.data[0] = SSL_HdskCertVerify;
 349     SSLEncodeInt(certVerify.contents.data+1, len+2, 3);
 350     SSLEncodeInt(certVerify.contents.data+4, len, 2);
 351
 352         err = sslRawSign(ctx,
 353                 ctx->signingPrivKey,
 354                 ctx->signingKeyCsp,
 355                 hashData,                                               // data to sign
 356                 36,                                                             // MD5 size + SHA1 size
 357                 certVerify.contents.data+6,             // signature destination
 358                 len,                                                    // we mallocd len+6
 359                 &outputLen);
 360         if(err) {
 361                 goto fail;
 362         }
 363
 364     assert(outputLen == len);
 365
 366     err = noErr;
 367
 368 fail:
 369     SSLFreeBuffer(shaMsgState, ctx);
 370     SSLFreeBuffer(md5MsgState, ctx);
 371
 372     return err;
 373 }
 374
 375 OSStatus
 376 SSLProcessCertificateVerify(SSLBuffer message, SSLContext *ctx)
 377 {   OSStatus        err;
 378     UInt8           hashData[36];
 379     UInt16          signatureLen;
 380     SSLBuffer       hashDataBuf, shaMsgState, md5MsgState;
 381     unsigned int    publicModulusLen;
 382
 383     shaMsgState.data = 0;
 384     md5MsgState.data = 0;
 385
 386     if (message.length < 2) {
 387         sslErrorLog("SSLProcessCertificateVerify: msg len error\n");
 388         return errSSLProtocol;
 389     }
 390
 391     signatureLen = (UInt16)SSLDecodeInt(message.data, 2);
 392     if (message.length != (unsigned)(2 + signatureLen)) {
 393         sslErrorLog("SSLProcessCertificateVerify: sig len error 1\n");
 394         return errSSLProtocol;
 395     }
 396
 397         assert(ctx->peerPubKey != NULL);
 398         publicModulusLen = sslKeyLengthInBytes(ctx->peerPubKey);
 399
 400     if (signatureLen != publicModulusLen) {
 401         sslErrorLog("SSLProcessCertificateVerify: sig len error 2\n");
 402         return errSSLProtocol;
 403     }
 404     hashDataBuf.data = hashData;
 405     hashDataBuf.length = 36;
 406
 407     if ((err = CloneHashState(SSLHashSHA1, ctx->shaState, shaMsgState, ctx)) != 0)
 408         goto fail;
 409     if ((err = CloneHashState(SSLHashMD5, ctx->md5State, md5MsgState, ctx)) != 0)
 410         goto fail;
 411         assert(ctx->sslTslCalls != NULL);
 412     if ((err = ctx->sslTslCalls->computeCertVfyMac(ctx, hashDataBuf,
 413                         shaMsgState, md5MsgState)) != 0)
 414         goto fail;
 415
 416         /*
 417          * The CSP does the decrypt & compare for us in one shot
 418          */
 419         err = sslRawVerify(ctx,
 420                 ctx->peerPubKey,
 421                 ctx->peerPubKeyCsp,             // FIXME - maybe we just use cspHand?
 422                 hashData,                               // data to verify
 423                 36,
 424                 message.data + 2,               // signature
 425                 signatureLen);
 426         if(err) {
 427                 SSLFatalSessionAlert(SSL_AlertDecryptError, ctx);
 428                 goto fail;
 429         }
 430     err = noErr;
 431
 432 fail:
 433     SSLFreeBuffer(shaMsgState, ctx);
 434     SSLFreeBuffer(md5MsgState, ctx);
 435
 436     return err;
 437 }