Fix SSL state transitions.
[openssl.git] / ssl / s3_srvr.c
index f762480a026a132f4ec864892797cf736911427d..274493e00277afda581ec0e279498b637ac96816 100644 (file)
 #include <openssl/rand.h>
 #include <openssl/objects.h>
 #include <openssl/evp.h>
+#include <openssl/hmac.h>
 #include <openssl/x509.h>
 #ifndef OPENSSL_NO_DH
 #include <openssl/dh.h>
 #include <openssl/md5.h>
 
 static SSL_METHOD *ssl3_get_server_method(int ver);
-
 #ifndef OPENSSL_NO_ECDH
 static int nid2curve_id(int nid);
 #endif
@@ -164,7 +164,7 @@ IMPLEMENT_ssl3_meth_func(SSLv3_server_method,
 int ssl3_accept(SSL *s)
        {
        BUF_MEM *buf;
-       unsigned long l,Time=time(NULL);
+       unsigned long l,Time=(unsigned long)time(NULL);
        void (*cb)(const SSL *ssl,int type,int val)=NULL;
        long num1;
        int ret= -1;
@@ -290,9 +290,18 @@ int ssl3_accept(SSL *s)
                case SSL3_ST_SW_SRVR_HELLO_B:
                        ret=ssl3_send_server_hello(s);
                        if (ret <= 0) goto end;
-
+#ifndef OPENSSL_NO_TLSEXT
                        if (s->hit)
-                               s->state=SSL3_ST_SW_CHANGE_A;
+                               {
+                               if (s->tlsext_ticket_expected)
+                                       s->state=SSL3_ST_SW_SESSION_TICKET_A;
+                               else
+                                       s->state=SSL3_ST_SW_CHANGE_A;
+                               }
+#else
+                       if (s->hit)
+                                       s->state=SSL3_ST_SW_CHANGE_A;
+#endif
                        else
                                s->state=SSL3_ST_SW_CERT_A;
                        s->init_num=0;
@@ -300,15 +309,30 @@ int ssl3_accept(SSL *s)
 
                case SSL3_ST_SW_CERT_A:
                case SSL3_ST_SW_CERT_B:
-                       /* Check if it is anon DH or anon ECDH */
-                       if (!(s->s3->tmp.new_cipher->algorithms & SSL_aNULL))
+                       /* Check if it is anon DH or anon ECDH or KRB5 */
+                       if (!(s->s3->tmp.new_cipher->algorithms & SSL_aNULL)
+                               && !(s->s3->tmp.new_cipher->algorithms & SSL_aKRB5))
                                {
                                ret=ssl3_send_server_certificate(s);
                                if (ret <= 0) goto end;
+#ifndef OPENSSL_NO_TLSEXT
+                               if (s->tlsext_status_expected)
+                                       s->state=SSL3_ST_SW_CERT_STATUS_A;
+                               else
+                                       s->state=SSL3_ST_SW_KEY_EXCH_A;
+                               }
+                       else
+                               {
+                               skip = 1;
+                               s->state=SSL3_ST_SW_KEY_EXCH_A;
+                               }
+#else
                                }
                        else
                                skip=1;
+
                        s->state=SSL3_ST_SW_KEY_EXCH_A;
+#endif
                        s->init_num=0;
                        break;
 
@@ -493,11 +517,34 @@ int ssl3_accept(SSL *s)
                        if (ret <= 0) goto end;
                        if (s->hit)
                                s->state=SSL_ST_OK;
+#ifndef OPENSSL_NO_TLSEXT
+                       else if (s->tlsext_ticket_expected)
+                               s->state=SSL3_ST_SW_SESSION_TICKET_A;
+#endif
                        else
                                s->state=SSL3_ST_SW_CHANGE_A;
                        s->init_num=0;
                        break;
 
+#ifndef OPENSSL_NO_TLSEXT
+               case SSL3_ST_SW_SESSION_TICKET_A:
+               case SSL3_ST_SW_SESSION_TICKET_B:
+                       ret=ssl3_send_newsession_ticket(s);
+                       if (ret <= 0) goto end;
+                       s->state=SSL3_ST_SW_CHANGE_A;
+                       s->init_num=0;
+                       break;
+
+               case SSL3_ST_SW_CERT_STATUS_A:
+               case SSL3_ST_SW_CERT_STATUS_B:
+                       ret=ssl3_send_cert_status(s);
+                       if (ret <= 0) goto end;
+                       s->state=SSL3_ST_SW_KEY_EXCH_A;
+                       s->init_num=0;
+                       break;
+
+#endif
+
                case SSL3_ST_SW_CHANGE_A:
                case SSL3_ST_SW_CHANGE_B:
 
@@ -679,9 +726,9 @@ int ssl3_get_client_hello(SSL *s)
         */
        if (s->state == SSL3_ST_SR_CLNT_HELLO_A)
                {
-               s->first_packet=1;
                s->state=SSL3_ST_SR_CLNT_HELLO_B;
                }
+       s->first_packet=1;
        n=s->method->ssl_get_message(s,
                SSL3_ST_SR_CLNT_HELLO_B,
                SSL3_ST_SR_CLNT_HELLO_C,
@@ -690,6 +737,7 @@ int ssl3_get_client_hello(SSL *s)
                &ok);
 
        if (!ok) return((int)n);
+       s->first_packet=0;
        d=p=(unsigned char *)s->init_msg;
 
        /* use version from inside client hello, not from record header
@@ -697,7 +745,8 @@ int ssl3_get_client_hello(SSL *s)
        s->client_version=(((int)p[0])<<8)|(int)p[1];
        p+=2;
 
-       if (s->client_version < s->version)
+       if ((s->version == DTLS1_VERSION && s->client_version > s->version) ||
+           (s->version != DTLS1_VERSION && s->client_version < s->version))
                {
                SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO, SSL_R_WRONG_VERSION_NUMBER);
                if ((s->client_version>>8) == SSL3_VERSION_MAJOR) 
@@ -725,14 +774,14 @@ int ssl3_get_client_hello(SSL *s)
         * might be written that become totally unsecure when compiled with
         * an earlier library version)
         */
-       if (j == 0 || (s->new_session && (s->options & SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION)))
+       if ((s->new_session && (s->options & SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION)))
                {
                if (!ssl_get_new_session(s,1))
                        goto err;
                }
        else
                {
-               i=ssl_get_prev_session(s,p,j);
+               i=ssl_get_prev_session(s, p, j, d + n);
                if (i == 1)
                        { /* previous session */
                        s->hit=1;
@@ -748,7 +797,7 @@ int ssl3_get_client_hello(SSL *s)
 
        p+=j;
 
-       if (SSL_version(s) == DTLS1_VERSION)
+       if (s->version == DTLS1_VERSION)
                {
                /* cookie stuff */
                cookie_len = *(p++);
@@ -895,6 +944,22 @@ int ssl3_get_client_hello(SSL *s)
                goto f_err;
                }
 
+#ifndef OPENSSL_NO_TLSEXT
+       /* TLS extensions*/
+       if (s->version > SSL3_VERSION)
+               {
+               if (!ssl_parse_clienthello_tlsext(s,&p,d,n, &al))
+                       {
+                       /* 'al' set by ssl_parse_clienthello_tlsext */
+                       SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO,SSL_R_PARSE_TLSEXT);
+                       goto f_err;
+                       }
+               }
+               if (ssl_check_clienthello_tlsext(s) <= 0) {
+                       SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO,SSL_R_CLIENTHELLO_TLSEXT);
+                       goto err;
+               }
+#endif
        /* Worst case, we will use the NULL compression, but if we have other
         * options, we will now look for them.  We have i-1 compression
         * algorithms from the client, starting at q. */
@@ -1038,7 +1103,7 @@ int ssl3_send_server_hello(SSL *s)
                {
                buf=(unsigned char *)s->init_buf->data;
                p=s->s3->server_random;
-               Time=time(NULL);                        /* Time */
+               Time=(unsigned long)time(NULL);                 /* Time */
                l2n(Time,p);
                if (RAND_pseudo_bytes(p,SSL3_RANDOM_SIZE-4) <= 0)
                        return -1;
@@ -1059,8 +1124,16 @@ int ssl3_send_server_hello(SSL *s)
                 * session-id if we want it to be single use.
                 * Currently I will not implement the '0' length session-id
                 * 12-Jan-98 - I'll now support the '0' length stuff.
+                *
+                * We also have an additional case where stateless session
+                * resumption is successful: we always send back the old
+                * session id. In this case s->hit is non zero: this can
+                * only happen if stateless session resumption is succesful
+                * if session caching is disabled so existing functionality
+                * is unaffected.
                 */
-               if (!(s->ctx->session_cache_mode & SSL_SESS_CACHE_SERVER))
+               if (!(s->ctx->session_cache_mode & SSL_SESS_CACHE_SERVER)
+                       && !s->hit)
                        s->session->session_id_length=0;
 
                sl=s->session->session_id_length;
@@ -1086,20 +1159,26 @@ int ssl3_send_server_hello(SSL *s)
                else
                        *(p++)=s->s3->tmp.new_compression->id;
 #endif
-
+#ifndef OPENSSL_NO_TLSEXT
+               if ((p = ssl_add_serverhello_tlsext(s, p, buf+SSL3_RT_MAX_PLAIN_LENGTH)) == NULL)
+                       {
+                       SSLerr(SSL_F_SSL3_SEND_SERVER_HELLO,ERR_R_INTERNAL_ERROR);
+                       return -1;
+                       }
+#endif
                /* do the header */
                l=(p-d);
                d=buf;
                *(d++)=SSL3_MT_SERVER_HELLO;
                l2n3(l,d);
 
-               s->state=SSL3_ST_CW_CLNT_HELLO_B;
+               s->state=SSL3_ST_SW_CLNT_HELLO_B;
                /* number of bytes to write */
                s->init_num=p-buf;
                s->init_off=0;
                }
 
-       /* SSL3_ST_CW_CLNT_HELLO_B */
+       /* SSL3_ST_SW_CLNT_HELLO_B */
        return(ssl3_do_write(s,SSL3_RT_HANDSHAKE));
        }
 
@@ -1123,7 +1202,7 @@ int ssl3_send_server_done(SSL *s)
                s->init_off=0;
                }
 
-       /* SSL3_ST_CW_CLNT_HELLO_B */
+       /* SSL3_ST_SW_SRVR_DONE_B */
        return(ssl3_do_write(s,SSL3_RT_HANDSHAKE));
        }
 
@@ -1366,11 +1445,11 @@ int ssl3_send_server_key_exchange(SSL *s)
 
                        /* XXX: For now, we only support named (not 
                         * generic) curves in ECDH ephemeral key exchanges.
-                        * In this situation, we need three additional bytes
+                        * In this situation, we need four additional bytes
                         * to encode the entire ServerECDHParams
                         * structure. 
                         */
-                       n = 3 + encodedlen;
+                       n = 4 + encodedlen;
 
                        /* We'll generate the serverKeyExchange message
                         * explicitly so we can set these to NULLs
@@ -1378,6 +1457,7 @@ int ssl3_send_server_key_exchange(SSL *s)
                        r[0]=NULL;
                        r[1]=NULL;
                        r[2]=NULL;
+                       r[3]=NULL;
                        }
                else 
 #endif /* !OPENSSL_NO_ECDH */
@@ -1428,12 +1508,14 @@ int ssl3_send_server_key_exchange(SSL *s)
                        {
                        /* XXX: For now, we only support named (not generic) curves.
                         * In this situation, the serverKeyExchange message has:
-                        * [1 byte CurveType], [1 byte CurveName]
+                        * [1 byte CurveType], [2 byte CurveName]
                         * [1 byte length of encoded point], followed by
                         * the actual encoded point itself
                         */
                        *p = NAMED_CURVE_TYPE;
                        p += 1;
+                       *p = 0;
+                       p += 1;
                        *p = curve_id;
                        p += 1;
                        *p = encodedlen;
@@ -1458,6 +1540,8 @@ int ssl3_send_server_key_exchange(SSL *s)
                                j=0;
                                for (num=2; num > 0; num--)
                                        {
+                                       EVP_MD_CTX_set_flags(&md_ctx,
+                                               EVP_MD_CTX_FLAG_NON_FIPS_ALLOW);
                                        EVP_DigestInit_ex(&md_ctx,(num == 2)
                                                ?s->ctx->md5:s->ctx->sha1, NULL);
                                        EVP_DigestUpdate(&md_ctx,&(s->s3->client_random[0]),SSL3_RANDOM_SIZE);
@@ -1637,23 +1721,6 @@ err:
        return(-1);
        }
 
-
-#ifndef OPENSSL_NO_ECDH
-static const int KDF1_SHA1_len = 20;
-static void *KDF1_SHA1(const void *in, size_t inlen, void *out, size_t *outlen)
-       {
-#ifndef OPENSSL_NO_SHA
-       if (*outlen < SHA_DIGEST_LENGTH)
-               return NULL;
-       else
-               *outlen = SHA_DIGEST_LENGTH;
-       return SHA1(in, inlen, out);
-#else
-       return NULL;
-#endif /* OPENSSL_NO_SHA */
-       }
-#endif /* OPENSSL_NO_ECDH */
-
 int ssl3_get_client_key_exchange(SSL *s)
        {
        int i,al,ok;
@@ -1723,8 +1790,9 @@ int ssl3_get_client_key_exchange(SSL *s)
                        rsa=pkey->pkey.rsa;
                        }
 
-               /* TLS */
-               if (s->version > SSL3_VERSION)
+               /* TLS and [incidentally] DTLS, including pre-0.9.8f */
+               if (s->version > SSL3_VERSION &&
+                   s->client_version != DTLS1_BAD_VER)
                        {
                        n2s(p,i);
                        if (n != i+2)
@@ -2009,6 +2077,24 @@ int ssl3_get_client_key_exchange(SSL *s)
                                SSL_R_DATA_LENGTH_TOO_LONG);
                        goto err;
                        }
+               if (!((pms[0] == (s->client_version>>8)) && (pms[1] == (s->client_version & 0xff))))
+                   {
+                   /* The premaster secret must contain the same version number as the
+                    * ClientHello to detect version rollback attacks (strangely, the
+                    * protocol does not offer such protection for DH ciphersuites).
+                    * However, buggy clients exist that send random bytes instead of
+                    * the protocol version.
+                    * If SSL_OP_TLS_ROLLBACK_BUG is set, tolerate such clients. 
+                    * (Perhaps we should have a separate BUG value for the Kerberos cipher)
+                    */
+                   if (!(s->options & SSL_OP_TLS_ROLLBACK_BUG))
+                       {
+                       SSLerr(SSL_F_SSL3_GET_CLIENT_KEY_EXCHANGE,
+                              SSL_AD_DECODE_ERROR);
+                       goto err;
+                       }
+                   }
+
                EVP_CIPHER_CTX_cleanup(&ciph_ctx);
 
                 s->session->master_key_length=
@@ -2017,7 +2103,7 @@ int ssl3_get_client_key_exchange(SSL *s)
 
                 if (kssl_ctx->client_princ)
                         {
-                        int len = strlen(kssl_ctx->client_princ);
+                        size_t len = strlen(kssl_ctx->client_princ);
                         if ( len < SSL_MAX_KRB5_PRINCIPAL_LENGTH ) 
                                 {
                                 s->session->krb5_client_princ_len = len;
@@ -2056,7 +2142,7 @@ int ssl3_get_client_key_exchange(SSL *s)
                if (l & SSL_kECDH) 
                        { 
                         /* use the certificate */
-                       tkey = s->cert->key->privatekey->pkey.ec;
+                       tkey = s->cert->pkeys[SSL_PKEY_ECC].privatekey->pkey.ec;
                        }
                else
                        {
@@ -2116,8 +2202,13 @@ int ssl3_get_client_key_exchange(SSL *s)
                                goto f_err;
                                }
 
-                       EC_POINT_copy(clnt_ecpoint,
-                           EC_KEY_get0_public_key(clnt_pub_pkey->pkey.ec));
+                       if (EC_POINT_copy(clnt_ecpoint,
+                           EC_KEY_get0_public_key(clnt_pub_pkey->pkey.ec)) == 0)
+                               {
+                               SSLerr(SSL_F_SSL3_GET_CLIENT_KEY_EXCHANGE,
+                                       ERR_R_EC_LIB);
+                               goto err;
+                               }
                         ret = 2; /* Skip certificate verify processing */
                         }
                 else
@@ -2156,14 +2247,7 @@ int ssl3_get_client_key_exchange(SSL *s)
                               ERR_R_ECDH_LIB);
                        goto err;
                        }
-               /* If field size is not more than 24 octets, then use SHA-1 hash of result;
-                * otherwise, use result (see section 4.8 of draft-ietf-tls-ecc-03.txt;
-                * this is new with this version of the Internet Draft).
-                */
-               if (field_size <= 24 * 8)
-                   i = ECDH_compute_key(p, KDF1_SHA1_len, clnt_ecpoint, srvr_ecdh, KDF1_SHA1);
-               else
-                   i = ECDH_compute_key(p, (field_size+7)/8, clnt_ecpoint, srvr_ecdh, NULL);
+               i = ECDH_compute_key(p, (field_size+7)/8, clnt_ecpoint, srvr_ecdh, NULL);
                 if (i <= 0)
                         {
                         SSLerr(SSL_F_SSL3_GET_CLIENT_KEY_EXCHANGE,
@@ -2611,3 +2695,145 @@ static int nid2curve_id(int nid)
        }
 }
 #endif
+#ifndef OPENSSL_NO_TLSEXT
+int ssl3_send_newsession_ticket(SSL *s)
+       {
+       if (s->state == SSL3_ST_SW_SESSION_TICKET_A)
+               {
+               unsigned char *p, *senc, *macstart;
+               int len, slen;
+               unsigned int hlen;
+               EVP_CIPHER_CTX ctx;
+               HMAC_CTX hctx;
+               unsigned char iv[EVP_MAX_IV_LENGTH];
+               unsigned char key_name[16];
+
+               /* get session encoding length */
+               slen = i2d_SSL_SESSION(s->session, NULL);
+               /* Some length values are 16 bits, so forget it if session is
+                * too long
+                */
+               if (slen > 0xFF00)
+                       return -1;
+               /* Grow buffer if need be: the length calculation is as
+                * follows 1 (size of message name) + 3 (message length
+                * bytes) + 4 (ticket lifetime hint) + 2 (ticket length) +
+                * 16 (key name) + max_iv_len (iv length) +
+                * session_length + max_enc_block_size (max encrypted session
+                * length) + max_md_size (HMAC).
+                */
+               if (!BUF_MEM_grow(s->init_buf,
+                       26 + EVP_MAX_IV_LENGTH + EVP_MAX_BLOCK_LENGTH +
+                       EVP_MAX_MD_SIZE + slen))
+                       return -1;
+               senc = OPENSSL_malloc(slen);
+               if (!senc)
+                       return -1;
+               p = senc;
+               i2d_SSL_SESSION(s->session, &p);
+
+               p=(unsigned char *)s->init_buf->data;
+               /* do the header */
+               *(p++)=SSL3_MT_NEWSESSION_TICKET;
+               /* Skip message length for now */
+               p += 3;
+               EVP_CIPHER_CTX_init(&ctx);
+               HMAC_CTX_init(&hctx);
+               /* Initialize HMAC and cipher contexts. If callback present
+                * it does all the work otherwise use generated values
+                * from parent ctx.
+                */
+               if (s->ctx->tlsext_ticket_key_cb)
+                       {
+                       if (s->ctx->tlsext_ticket_key_cb(s, key_name, iv, &ctx,
+                                                        &hctx, 1) < 0)
+                               {
+                               OPENSSL_free(senc);
+                               return -1;
+                               }
+                       }
+               else
+                       {
+                       RAND_pseudo_bytes(iv, 16);
+                       EVP_EncryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL,
+                                       s->ctx->tlsext_tick_aes_key, iv);
+                       HMAC_Init_ex(&hctx, s->ctx->tlsext_tick_hmac_key, 16,
+                                       tlsext_tick_md(), NULL);
+                       memcpy(key_name, s->ctx->tlsext_tick_key_name, 16);
+                       }
+               l2n(s->session->tlsext_tick_lifetime_hint, p);
+               /* Skip ticket length for now */
+               p += 2;
+               /* Output key name */
+               macstart = p;
+               memcpy(p, key_name, 16);
+               p += 16;
+               /* output IV */
+               memcpy(p, iv, EVP_CIPHER_CTX_iv_length(&ctx));
+               p += EVP_CIPHER_CTX_iv_length(&ctx);
+               /* Encrypt session data */
+               EVP_EncryptUpdate(&ctx, p, &len, senc, slen);
+               p += len;
+               EVP_EncryptFinal(&ctx, p, &len);
+               p += len;
+               EVP_CIPHER_CTX_cleanup(&ctx);
+
+               HMAC_Update(&hctx, macstart, p - macstart);
+               HMAC_Final(&hctx, p, &hlen);
+               HMAC_CTX_cleanup(&hctx);
+
+               p += hlen;
+               /* Now write out lengths: p points to end of data written */
+               /* Total length */
+               len = p - (unsigned char *)s->init_buf->data;
+               p=(unsigned char *)s->init_buf->data + 1;
+               l2n3(len - 4, p); /* Message length */
+               p += 4;
+               s2n(len - 10, p);  /* Ticket length */
+
+               /* number of bytes to write */
+               s->init_num= len;
+               s->state=SSL3_ST_SW_SESSION_TICKET_B;
+               s->init_off=0;
+               OPENSSL_free(senc);
+               }
+
+       /* SSL3_ST_SW_SESSION_TICKET_B */
+       return(ssl3_do_write(s,SSL3_RT_HANDSHAKE));
+       }
+
+int ssl3_send_cert_status(SSL *s)
+       {
+       if (s->state == SSL3_ST_SW_CERT_STATUS_A)
+               {
+               unsigned char *p;
+               /* Grow buffer if need be: the length calculation is as
+                * follows 1 (message type) + 3 (message length) +
+                * 1 (ocsp response type) + 3 (ocsp response length)
+                * + (ocsp response)
+                */
+               if (!BUF_MEM_grow(s->init_buf, 8 + s->tlsext_ocsp_resplen))
+                       return -1;
+
+               p=(unsigned char *)s->init_buf->data;
+
+               /* do the header */
+               *(p++)=SSL3_MT_CERTIFICATE_STATUS;
+               /* message length */
+               l2n3(s->tlsext_ocsp_resplen + 4, p);
+               /* status type */
+               *(p++)= s->tlsext_status_type;
+               /* length of OCSP response */
+               l2n3(s->tlsext_ocsp_resplen, p);
+               /* actual response */
+               memcpy(p, s->tlsext_ocsp_resp, s->tlsext_ocsp_resplen);
+               /* number of bytes to write */
+               s->init_num = 8 + s->tlsext_ocsp_resplen;
+               s->state=SSL3_ST_SW_CERT_STATUS_B;
+               s->init_off = 0;
+               }
+
+       /* SSL3_ST_SW_CERT_STATUS_B */
+       return(ssl3_do_write(s,SSL3_RT_HANDSHAKE));
+       }
+#endif