The message header for fake SSL 3.0/TLS 1.0 client hellos created from
[openssl.git] / ssl / s23_srvr.c
index 888ffaca066dd0bb362881d0953bdd26adab9bf4..563531f1201864800a0a36c20d61a142e897e572 100644 (file)
  */
 
 #include <stdio.h>
-#include "buffer.h"
-#include "rand.h"
-#include "objects.h"
-#include "evp.h"
+#include <openssl/buffer.h>
+#include <openssl/rand.h>
+#include <openssl/objects.h>
+#include <openssl/evp.h>
 #include "ssl_locl.h"
 
-#define BREAK break
-
-#ifndef NOPROTO
+static SSL_METHOD *ssl23_get_server_method(int ver);
 int ssl23_get_client_hello(SSL *s);
-#else
-int ssl23_get_client_hello();
-#endif
-
-static SSL_METHOD *ssl23_get_server_method(ver)
-int ver;
+static SSL_METHOD *ssl23_get_server_method(int ver)
        {
+#ifndef OPENSSL_NO_SSL2
        if (ver == SSL2_VERSION)
                return(SSLv2_server_method());
-       else if (ver == SSL3_VERSION)
+#endif
+       if (ver == SSL3_VERSION)
                return(SSLv3_server_method());
        else if (ver == TLS1_VERSION)
                return(TLSv1_server_method());
@@ -84,24 +79,23 @@ int ver;
                return(NULL);
        }
 
-SSL_METHOD *SSLv23_server_method()
+SSL_METHOD *SSLv23_server_method(void)
        {
        static int init=1;
        static SSL_METHOD SSLv23_server_data;
 
        if (init)
                {
-               init=0;
                memcpy((char *)&SSLv23_server_data,
                        (char *)sslv23_base_method(),sizeof(SSL_METHOD));
                SSLv23_server_data.ssl_accept=ssl23_accept;
                SSLv23_server_data.get_ssl_method=ssl23_get_server_method;
+               init=0;
                }
        return(&SSLv23_server_data);
        }
 
-int ssl23_accept(s)
-SSL *s;
+int ssl23_accept(SSL *s)
        {
        BUF_MEM *buf;
        unsigned long Time=time(NULL);
@@ -109,7 +103,7 @@ SSL *s;
        int ret= -1;
        int new_state,state;
 
-       RAND_seed((unsigned char *)&Time,sizeof(Time));
+       RAND_add(&Time,sizeof(Time),0);
        ERR_clear_error();
        clear_sys_error();
 
@@ -132,6 +126,7 @@ SSL *s;
                case SSL_ST_BEFORE|SSL_ST_ACCEPT:
                case SSL_ST_OK|SSL_ST_ACCEPT:
 
+                       s->server=1;
                        if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_START,1);
 
                        /* s->version=SSL3_VERSION; */
@@ -155,7 +150,7 @@ SSL *s;
                        ssl3_init_finished_mac(s);
 
                        s->state=SSL23_ST_SR_CLNT_HELLO_A;
-                       s->ctx->sess_accept++;
+                       s->ctx->stats.sess_accept++;
                        s->init_num=0;
                        break;
 
@@ -191,24 +186,41 @@ end:
        }
 
 
-int ssl23_get_client_hello(s)
-SSL *s;
+int ssl23_get_client_hello(SSL *s)
        {
-       char buf_space[8];
+       char buf_space[11]; /* Request this many bytes in initial read.
+                            * We can detect SSL 3.0/TLS 1.0 Client Hellos
+                            * ('type == 3') correctly only when the following
+                            * is in a single record, which is not guaranteed by
+                            * the protocol specification:
+                            * Byte  Content
+                            *  0     type            \
+                            *  1/2   version          > record header
+                            *  3/4   length          /
+                            *  5     msg_type        \
+                            *  6-8   length           > Client Hello message
+                            *  9/10  client_version  /
+                            */
        char *buf= &(buf_space[0]);
-       unsigned char *p,*d,*dd;
+       unsigned char *p,*d,*d_len,*dd;
        unsigned int i;
        unsigned int csl,sil,cl;
-       int n=0,j,tls1=0;
-       int type=0,use_sslv2_strong=0;
+       int n=0,j;
+       int type=0;
+       int v[2];
+#ifndef OPENSSL_NO_RSA
+       int use_sslv2_strong=0;
+#endif
 
-       /* read the initial header */
        if (s->state == SSL23_ST_SR_CLNT_HELLO_A)
                {
+               /* read the initial header */
+               v[0]=v[1]=0;
+
                if (!ssl3_setup_buffers(s)) goto err;
 
-               n=ssl23_read_bytes(s,7);
-               if (n != 7) return(n);
+               n=ssl23_read_bytes(s, sizeof buf_space);
+               if (n != sizeof buf_space) return(n); /* n == -1 || n == 0 */
 
                p=s->packet;
 
@@ -216,25 +228,32 @@ SSL *s;
 
                if ((p[0] & 0x80) && (p[2] == SSL2_MT_CLIENT_HELLO))
                        {
-                       /* SSLv2 header */
+                       /*
+                        * SSLv2 header
+                        */
                        if ((p[3] == 0x00) && (p[4] == 0x02))
                                {
+                               v[0]=p[3]; v[1]=p[4];
                                /* SSLv2 */
                                if (!(s->options & SSL_OP_NO_SSLv2))
                                        type=1;
                                }
                        else if (p[3] == SSL3_VERSION_MAJOR)
                                {
+                               v[0]=p[3]; v[1]=p[4];
                                /* SSLv3/TLSv1 */
                                if (p[4] >= TLS1_VERSION_MINOR)
                                        {
                                        if (!(s->options & SSL_OP_NO_TLSv1))
                                                {
-                                               tls1=1;
+                                               s->version=TLS1_VERSION;
+                                               /* type=2; */ /* done later to survive restarts */
                                                s->state=SSL23_ST_SR_CLNT_HELLO_B;
                                                }
                                        else if (!(s->options & SSL_OP_NO_SSLv3))
                                                {
+                                               s->version=SSL3_VERSION;
+                                               /* type=2; */
                                                s->state=SSL23_ST_SR_CLNT_HELLO_B;
                                                }
                                        else if (!(s->options & SSL_OP_NO_SSLv2))
@@ -243,81 +262,59 @@ SSL *s;
                                                }
                                        }
                                else if (!(s->options & SSL_OP_NO_SSLv3))
+                                       {
+                                       s->version=SSL3_VERSION;
+                                       /* type=2; */
                                        s->state=SSL23_ST_SR_CLNT_HELLO_B;
+                                       }
                                else if (!(s->options & SSL_OP_NO_SSLv2))
                                        type=1;
 
-                               if (s->options & SSL_OP_NON_EXPORT_FIRST)
-                                       {
-                                       STACK *sk;
-                                       SSL_CIPHER *c;
-                                       int ne2,ne3;
-
-                                       j=((p[0]&0x7f)<<8)|p[1];
-                                       if (j > (1024*4))
-                                               {
-                                               SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_RECORD_TOO_LARGE);
-                                               goto err;
-                                               }
-
-                                       n=ssl23_read_bytes(s,j+2);
-                                       if (n <= 0) return(n);
-                                       p=s->packet;
-
-                                       if ((buf=Malloc(n)) == NULL)
-                                               {
-                                               SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,ERR_R_MALLOC_FAILURE);
-                                               goto err;
-                                               }
-                                       memcpy(buf,p,n);
-
-                                       p+=5;
-                                       n2s(p,csl);
-                                       p+=4;
-
-                                       sk=ssl_bytes_to_cipher_list(
-                                               s,p,csl,NULL);
-                                       if (sk != NULL)
-                                               {
-                                               ne2=ne3=0;
-                                               for (j=0; j<sk_num(sk); j++)
-                                                       {
-                                                       c=(SSL_CIPHER *)sk_value(sk,j);
-                                                       if (!(c->algorithms & SSL_EXP))
-                                                               {
-                                                               if ((c->id>>24L) == 2L)
-                                                                       ne2=1;
-                                                               else
-                                                                       ne3=1;
-                                                               }
-                                                       }
-                                               if (ne2 && !ne3)
-                                                       {
-                                                       type=1;
-                                                       use_sslv2_strong=1;
-                                                       goto next_bit;
-                                                       }
-                                               }
-                                       }
                                }
                        }
                else if ((p[0] == SSL3_RT_HANDSHAKE) &&
                         (p[1] == SSL3_VERSION_MAJOR) &&
-                        (p[5] == SSL3_MT_CLIENT_HELLO))
+                        (p[5] == SSL3_MT_CLIENT_HELLO) &&
+                        ((p[3] == 0 && p[4] < 5 /* silly record length? */)
+                               || (p[9] == p[1])))
                        {
-                       /* true SSLv3 or tls1 */
-                       if (p[2] >= TLS1_VERSION_MINOR)
+                       /*
+                        * SSLv3 or tls1 header
+                        */
+                       
+                       v[0]=p[1]; /* major version (= SSL3_VERSION_MAJOR) */
+                       /* We must look at client_version inside the Client Hello message
+                        * to get the correct minor version.
+                        * However if we have only a pathologically small fragment of the
+                        * Client Hello message, this would be difficult, we'd have
+                        * to read at least one additional record to find out.
+                        * This doesn't usually happen in real life, so we just complain
+                        * for now.
+                        */
+                       if (p[3] == 0 && p[4] < 6)
+                               {
+                               SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_RECORD_TOO_SMALL);
+                               goto err;
+                               }
+                       v[1]=p[10]; /* minor version according to client_version */
+                       if (v[1] >= TLS1_VERSION_MINOR)
                                {
                                if (!(s->options & SSL_OP_NO_TLSv1))
                                        {
+                                       s->version=TLS1_VERSION;
                                        type=3;
-                                       tls1=1;
                                        }
                                else if (!(s->options & SSL_OP_NO_SSLv3))
+                                       {
+                                       s->version=SSL3_VERSION;
                                        type=3;
+                                       }
                                }
                        else if (!(s->options & SSL_OP_NO_SSLv3))
+                               {
+                               s->version=SSL3_VERSION;
                                type=3;
+                               }
                        }
                else if ((strncmp("GET ", (char *)p,4) == 0) ||
                         (strncmp("POST ",(char *)p,5) == 0) ||
@@ -334,12 +331,16 @@ SSL *s;
                        }
                }
 
-next_bit:
        if (s->state == SSL23_ST_SR_CLNT_HELLO_B)
                {
-               /* we have a SSLv3/TLSv1 in a SSLv2 header */
+               /* we have SSLv3/TLSv1 in an SSLv2 header
+                * (other cases skip this state) */
+
                type=2;
                p=s->packet;
+               v[0] = p[3]; /* == SSL3_VERSION_MAJOR */
+               v[1] = p[4];
+
                n=((p[0]&0x7f)<<8)|p[1];
                if (n > (1024*4))
                        {
@@ -364,14 +365,18 @@ next_bit:
                        goto err;
                        }
 
-               *(d++)=SSL3_VERSION_MAJOR;
-               if (tls1)
-                       *(d++)=TLS1_VERSION_MINOR;
-               else
-                       *(d++)=SSL3_VERSION_MINOR;
+               /* record header: msg_type ... */
+               *(d++) = SSL3_MT_CLIENT_HELLO;
+               /* ... and length (actual value will be written later) */
+               d_len = d;
+               d += 3;
+
+               /* client_version */
+               *(d++) = SSL3_VERSION_MAJOR; /* == v[0] */
+               *(d++) = v[1];
 
                /* lets populate the random area */
-               /* get the chalenge_length */
+               /* get the challenge_length */
                i=(cl > SSL3_RANDOM_SIZE)?SSL3_RANDOM_SIZE:cl;
                memset(d,0,SSL3_RANDOM_SIZE);
                memcpy(&(d[SSL3_RANDOM_SIZE-i]),&(p[csl+sil]),i);
@@ -398,6 +403,7 @@ next_bit:
                *(d++)=0;
                
                i=(d-(unsigned char *)s->init_buf->data);
+               l2n3((long)i, d_len);
 
                /* get the data reused from the init_buf */
                s->s3->tmp.reuse_message=1;
@@ -405,8 +411,15 @@ next_bit:
                s->s3->tmp.message_size=i;
                }
 
+       /* imaginary new state (for program structure): */
+       /* s->state = SSL23_SR_CLNT_HELLO_C */
+
        if (type == 1)
                {
+#ifdef OPENSSL_NO_SSL2
+               SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_UNSUPPORTED_PROTOCOL);
+               goto err;
+#else
                /* we are talking sslv2 */
                /* we need to clean up the SSLv3/TLSv1 setup and put in the
                 * sslv2 stuff. */
@@ -429,12 +442,15 @@ next_bit:
 
                s->state=SSL2_ST_GET_CLIENT_HELLO_A;
                if ((s->options & SSL_OP_MSIE_SSLV2_RSA_PADDING) ||
-                       use_sslv2_strong)
+                       use_sslv2_strong ||
+                       (s->options & SSL_OP_NO_TLSv1 && s->options & SSL_OP_NO_SSLv3))
                        s->s2->ssl2_rollback=0;
                else
+                       /* reject SSL 2.0 session if client supports SSL 3.0 or TLS 1.0
+                        * (SSL 3.0 draft/RFC 2246, App. E.2) */
                        s->s2->ssl2_rollback=1;
 
-               /* setup the 5 bytes we have read so we get them from
+               /* setup the n bytes we have read so we get them from
                 * the sslv2 buffer */
                s->rstate=SSL_ST_READ_HEADER;
                s->packet_length=n;
@@ -445,11 +461,12 @@ next_bit:
 
                s->method=SSLv2_server_method();
                s->handshake_func=s->method->ssl_accept;
+#endif
                }
 
        if ((type == 2) || (type == 3))
                {
-               /* we have SSLv3/TLSv1 */
+               /* we have SSLv3/TLSv1 (type 2: SSL2 style, type 3: SSL3/TLS style) */
 
                if (!ssl_init_wbio_buffer(s,1)) goto err;
 
@@ -474,16 +491,13 @@ next_bit:
                        s->s3->rbuf.offset=0;
                        }
 
-               if (tls1)
-                       {
-                       s->version=TLS1_VERSION;
-                       s->method=TLSv1_server_method();
-                       }
+               if (s->version == TLS1_VERSION)
+                       s->method = TLSv1_server_method();
                else
-                       {
-                       s->version=SSL3_VERSION;
-                       s->method=SSLv3_server_method();
-                       }
+                       s->method = SSLv3_server_method();
+#if 0 /* ssl3_get_client_hello does this */
+               s->client_version=(v[0]<<8)|v[1];
+#endif
                s->handshake_func=s->method->ssl_accept;
                }
        
@@ -495,11 +509,10 @@ next_bit:
                }
        s->init_num=0;
 
-       if (buf != buf_space) Free(buf);
+       if (buf != buf_space) OPENSSL_free(buf);
        s->first_packet=1;
        return(SSL_accept(s));
 err:
-       if (buf != buf_space) Free(buf);
+       if (buf != buf_space) OPENSSL_free(buf);
        return(-1);
        }
-