use correct function name
[openssl.git] / ssl / s3_pkt.c
index 012e9bca48be3ea0979b2f80943d10e43b3b4cfd..d1cd752209ff973162a1882feb1a6f15181b3a56 100644 (file)
  */
 
 #include <stdio.h>
+#include <limits.h>
 #include <errno.h>
 #define USE_SOCKETS
 #include "ssl_locl.h"
@@ -272,6 +273,12 @@ int ssl3_read_n(SSL *s, int n, int max, int extend)
        return(n);
        }
 
+/* MAX_EMPTY_RECORDS defines the number of consecutive, empty records that will
+ * be processed per call to ssl3_get_record. Without this limit an attacker
+ * could send empty records at a faster rate than we can process and cause
+ * ssl3_get_record to loop forever. */
+#define MAX_EMPTY_RECORDS 32
+
 /* Call this to get a new input record.
  * It will return <= 0 if more data is needed, normally due to an error
  * or non-blocking IO.
@@ -292,6 +299,7 @@ static int ssl3_get_record(SSL *s)
        short version;
        unsigned mac_size, orig_len;
        size_t extra;
+       unsigned empty_record_count = 0;
 
        rr= &(s->s3->rrec);
        sess=s->session;
@@ -335,7 +343,7 @@ fprintf(stderr, "Record type=%d, Length=%d\n", rr->type, rr->length);
                        if (version != s->version)
                                {
                                SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
-                                if ((s->version & 0xFF00) == (version & 0xFF00))
+                                if ((s->version & 0xFF00) == (version & 0xFF00) && !s->enc_write_ctx && !s->write_hash)
                                        /* Send back error using their minor version number :-) */
                                        s->version = (unsigned short)version;
                                al=SSL_AD_PROTOCOL_VERSION;
@@ -398,7 +406,6 @@ fprintf(stderr, "Record type=%d, Length=%d\n", rr->type, rr->length);
 
        /* decrypt in place in 'rr->input' */
        rr->data=rr->input;
-       orig_len=rr->length;
 
        enc_err = s->method->ssl3_enc->enc(s,0);
        /* enc_err is:
@@ -408,7 +415,7 @@ fprintf(stderr, "Record type=%d, Length=%d\n", rr->type, rr->length);
        if (enc_err == 0)
                {
                al=SSL_AD_DECRYPTION_FAILED;
-               SSLerr(SSL_F_TLS1_ENC,SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
+               SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
                goto f_err;
                }
 
@@ -429,6 +436,9 @@ printf("\n");
                mac_size=EVP_MD_CTX_size(s->read_hash);
                OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
 
+               /* kludge: *_cbc_remove_padding passes padding length in rr->type */
+               orig_len = rr->length+((unsigned int)rr->type>>8);
+
                /* orig_len is the length of the record before any padding was
                 * removed. This is public information, as is the MAC in use,
                 * therefore we can safely process the record in a different
@@ -520,7 +530,17 @@ printf("\n");
        s->packet_length=0;
 
        /* just read a 0 length packet */
-       if (rr->length == 0) goto again;
+       if (rr->length == 0)
+               {
+               empty_record_count++;
+               if (empty_record_count > MAX_EMPTY_RECORDS)
+                       {
+                       al=SSL_AD_UNEXPECTED_MESSAGE;
+                       SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_RECORD_TOO_SMALL);
+                       goto f_err;
+                       }
+               goto again;
+               }
 
 #if 0
 fprintf(stderr, "Ultimate Record type=%d, Length=%d\n", rr->type, rr->length);
@@ -578,10 +598,11 @@ int ssl3_do_compress(SSL *ssl)
 int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len)
        {
        const unsigned char *buf=buf_;
-       unsigned int tot,n,nw;
-       int i;
+       unsigned int n,nw;
+       int i,tot;
 
        s->rwstate=SSL_NOTHING;
+       OPENSSL_assert(s->s3->wnum <= INT_MAX);
        tot=s->s3->wnum;
        s->s3->wnum=0;
 
@@ -596,6 +617,22 @@ int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len)
                        }
                }
 
+       /* ensure that if we end up with a smaller value of data to write 
+        * out than the the original len from a write which didn't complete 
+        * for non-blocking I/O and also somehow ended up avoiding 
+        * the check for this in ssl3_write_pending/SSL_R_BAD_WRITE_RETRY as
+        * it must never be possible to end up with (len-tot) as a large
+        * number that will then promptly send beyond the end of the users
+        * buffer ... so we trap and report the error in a way the user
+        * will notice
+        */
+       if (len < tot)
+               {
+               SSLerr(SSL_F_SSL3_WRITE_BYTES,SSL_R_BAD_LENGTH);
+               return(-1);
+               }
+
+
        n=(len-tot);
        for (;;)
                {
@@ -639,9 +676,6 @@ static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
        SSL3_BUFFER *wb=&(s->s3->wbuf);
        SSL_SESSION *sess;
 
-       if (wb->buf == NULL)
-               if (!ssl3_setup_write_buffer(s))
-                       return -1;
 
        /* first check if there is a SSL3_BUFFER still being written
         * out.  This will happen with non blocking IO */
@@ -657,6 +691,10 @@ static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
                /* if it went, fall through and send more stuff */
                }
 
+       if (wb->buf == NULL)
+               if (!ssl3_setup_write_buffer(s))
+                       return -1;
+
        if (len == 0 && !create_empty_fragment)
                return 0;
 
@@ -818,8 +856,7 @@ static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
                wr->length += eivlen;
                }
 
-       /* ssl3_enc can only have an error on read */
-       s->method->ssl3_enc->enc(s,1);
+       if(s->method->ssl3_enc->enc(s,1)<1) goto err;
 
        /* record length after mac and block padding */
        s2n(wr->length,plen);
@@ -947,7 +984,7 @@ int ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
                if (!ssl3_setup_read_buffer(s))
                        return(-1);
 
-       if ((type && (type != SSL3_RT_APPLICATION_DATA) && (type != SSL3_RT_HANDSHAKE) && type) ||
+       if ((type && (type != SSL3_RT_APPLICATION_DATA) && (type != SSL3_RT_HANDSHAKE)) ||
            (peek && (type != SSL3_RT_APPLICATION_DATA)))
                {
                SSLerr(SSL_F_SSL3_READ_BYTES, ERR_R_INTERNAL_ERROR);
@@ -1053,7 +1090,7 @@ start:
                                {
                                s->rstate=SSL_ST_READ_HEADER;
                                rr->off=0;
-                               if (s->mode & SSL_MODE_RELEASE_BUFFERS)
+                               if (s->mode & SSL_MODE_RELEASE_BUFFERS && s->s3->rbuf.left == 0)
                                        ssl3_release_read_buffer(s);
                                }
                        }
@@ -1295,6 +1332,15 @@ start:
                        goto f_err;
                        }
 
+               if (!(s->s3->flags & SSL3_FLAGS_CCS_OK))
+                       {
+                       al=SSL_AD_UNEXPECTED_MESSAGE;
+                       SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_CCS_RECEIVED_EARLY);
+                       goto f_err;
+                       }
+
+               s->s3->flags &= ~SSL3_FLAGS_CCS_OK;
+
                rr->length=0;
 
                if (s->msg_callback)
@@ -1429,7 +1475,7 @@ int ssl3_do_change_cipher_spec(SSL *s)
 
        if (s->s3->tmp.key_block == NULL)
                {
-               if (s->session == NULL
+               if (s->session == NULL || s->session->master_key_length == 0)
                        {
                        /* might happen if dtls1_read_bytes() calls this */
                        SSLerr(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC,SSL_R_CCS_RECEIVED_EARLY);
@@ -1457,8 +1503,14 @@ int ssl3_do_change_cipher_spec(SSL *s)
                slen=s->method->ssl3_enc->client_finished_label_len;
                }
 
-       s->s3->tmp.peer_finish_md_len = s->method->ssl3_enc->final_finish_mac(s,
+       i = s->method->ssl3_enc->final_finish_mac(s,
                sender,slen,s->s3->tmp.peer_finish_md);
+       if (i == 0)
+               {
+               SSLerr(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR);
+               return 0;
+               }
+       s->s3->tmp.peer_finish_md_len = i;
 
        return(1);
        }