s2_pkt.c

mediastreamer2是开源的网络传输媒体流的库

	 */
	s->packet=s->s2->rbuf;
	while (newb < (int)n)
		{
		clear_sys_error();
		if (s->rbio != NULL)
			{
			s->rwstate=SSL_READING;
			i=BIO_read(s->rbio,(char *)&(s->s2->rbuf[off+newb]),
				max-newb);
			}
		else
			{
			SSLerr(SSL_F_READ_N,SSL_R_READ_BIO_NOT_SET);
			i= -1;
			}
#ifdef PKT_DEBUG
		if (s->debug & 0x01) sleep(1);
#endif
		if (i <= 0)
			{
			s->s2->rbuf_left+=newb;
			return(i);
			}
		newb+=i;
		}

	/* record unread data */
	if (newb > (int)n)
		{
		s->s2->rbuf_offs=n+off;
		s->s2->rbuf_left=newb-n;
		}
	else
		{
		s->s2->rbuf_offs=0;
		s->s2->rbuf_left=0;
		}
	if (extend)
		s->packet_length+=n;
	else
		s->packet_length=n;
	s->rwstate=SSL_NOTHING;
	return(n);
	}

int ssl2_write(SSL *s, const void *_buf, int len)
	{
	const unsigned char *buf=_buf;
	unsigned int n,tot;
	int i;

	if (SSL_in_init(s) && !s->in_handshake)
		{
		i=s->handshake_func(s);
		if (i < 0) return(i);
		if (i == 0)
			{
			SSLerr(SSL_F_SSL2_WRITE,SSL_R_SSL_HANDSHAKE_FAILURE);
			return(-1);
			}
		}

	if (s->error)
		{
		ssl2_write_error(s);
		if (s->error)
			return(-1);
		}

	clear_sys_error();
	s->rwstate=SSL_NOTHING;
	if (len <= 0) return(len);

	tot=s->s2->wnum;
	s->s2->wnum=0;

	n=(len-tot);
	for (;;)
		{
		i=do_ssl_write(s,&(buf[tot]),n);
		if (i <= 0)
			{
			s->s2->wnum=tot;
			return(i);
			}
		if ((i == (int)n) ||
			(s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE))
			{
			return(tot+i);
			}
		
		n-=i;
		tot+=i;
		}
	}

static int write_pending(SSL *s, const unsigned char *buf, unsigned int len)
	{
	int i;

	/* s->s2->wpend_len != 0 MUST be true. */

	/* check that they have given us the same buffer to
	 * write */
	if ((s->s2->wpend_tot > (int)len) ||
		((s->s2->wpend_buf != buf) &&
		 !(s->mode & SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER)))
		{
		SSLerr(SSL_F_WRITE_PENDING,SSL_R_BAD_WRITE_RETRY);
		return(-1);
		}

	for (;;)
		{
		clear_sys_error();
		if (s->wbio != NULL)
			{
			s->rwstate=SSL_WRITING;
			i=BIO_write(s->wbio,
				(char *)&(s->s2->write_ptr[s->s2->wpend_off]),
				(unsigned int)s->s2->wpend_len);
			}
		else
			{
			SSLerr(SSL_F_WRITE_PENDING,SSL_R_WRITE_BIO_NOT_SET);
			i= -1;
			}
#ifdef PKT_DEBUG
		if (s->debug & 0x01) sleep(1);
#endif
		if (i == s->s2->wpend_len)
			{
			s->s2->wpend_len=0;
			s->rwstate=SSL_NOTHING;
			return(s->s2->wpend_ret);
			}
		else if (i <= 0)
			return(i);
		s->s2->wpend_off+=i;
		s->s2->wpend_len-=i;
		}
	}

static int do_ssl_write(SSL *s, const unsigned char *buf, unsigned int len)
	{
	unsigned int j,k,olen,p,mac_size,bs;
	register unsigned char *pp;

	olen=len;

	/* first check if there is data from an encryption waiting to
	 * be sent - it must be sent because the other end is waiting.
	 * This will happen with non-blocking IO.  We print it and then
	 * return.
	 */
	if (s->s2->wpend_len != 0) return(write_pending(s,buf,len));

	/* set mac_size to mac size */
	if (s->s2->clear_text)
		mac_size=0;
	else
		mac_size=EVP_MD_size(s->write_hash);

	/* lets set the pad p */
	if (s->s2->clear_text)
		{
		if (len > SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER)
			len=SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER;
		p=0;
		s->s2->three_byte_header=0;
		/* len=len; */
		}
	else
		{
		bs=EVP_CIPHER_CTX_block_size(s->enc_read_ctx);
		j=len+mac_size;
		/* Two-byte headers allow for a larger record length than
		 * three-byte headers, but we can't use them if we need
		 * padding or if we have to set the escape bit. */
		if ((j > SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER) &&
			(!s->s2->escape))
			{
			if (j > SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER)
				j=SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER;
			/* set k to the max number of bytes with 2
			 * byte header */
			k=j-(j%bs);
			/* how many data bytes? */
			len=k-mac_size; 
			s->s2->three_byte_header=0;
			p=0;
			}
		else if ((bs <= 1) && (!s->s2->escape))
			{
			/* j <= SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER, thus
			 * j < SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER */
			s->s2->three_byte_header=0;
			p=0;
			}
		else /* we may have to use a 3 byte header */
			{
			/* If s->s2->escape is not set, then
			 * j <= SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER, and thus
			 * j < SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER. */
			p=(j%bs);
			p=(p == 0)?0:(bs-p);
			if (s->s2->escape)
				{
				s->s2->three_byte_header=1;
				if (j > SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER)
					j=SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER;
				}
			else
				s->s2->three_byte_header=(p == 0)?0:1;
			}
		}

	/* Now
	 *      j <= SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER
	 * holds, and if s->s2->three_byte_header is set, then even
	 *      j <= SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER.
	 */

	/* mac_size is the number of MAC bytes
	 * len is the number of data bytes we are going to send
	 * p is the number of padding bytes
	 * (if it is a two-byte header, then p == 0) */

	s->s2->wlength=len;
	s->s2->padding=p;
	s->s2->mac_data= &(s->s2->wbuf[3]);
	s->s2->wact_data= &(s->s2->wbuf[3+mac_size]);
	/* we copy the data into s->s2->wbuf */
	memcpy(s->s2->wact_data,buf,len);
	if (p)
		memset(&(s->s2->wact_data[len]),0,p); /* arbitrary padding */

	if (!s->s2->clear_text)
		{
		s->s2->wact_data_length=len+p;
		ssl2_mac(s,s->s2->mac_data,1);
		s->s2->wlength+=p+mac_size;
		ssl2_enc(s,1);
		}

	/* package up the header */
	s->s2->wpend_len=s->s2->wlength;
	if (s->s2->three_byte_header) /* 3 byte header */
		{
		pp=s->s2->mac_data;
		pp-=3;
		pp[0]=(s->s2->wlength>>8)&(THREE_BYTE_MASK>>8);
		if (s->s2->escape) pp[0]|=SEC_ESC_BIT;
		pp[1]=s->s2->wlength&0xff;
		pp[2]=s->s2->padding;
		s->s2->wpend_len+=3;
		}
	else
		{
		pp=s->s2->mac_data;
		pp-=2;
		pp[0]=((s->s2->wlength>>8)&(TWO_BYTE_MASK>>8))|TWO_BYTE_BIT;
		pp[1]=s->s2->wlength&0xff;
		s->s2->wpend_len+=2;
		}
	s->s2->write_ptr=pp;
	
	INC32(s->s2->write_sequence); /* expect next number */

	/* lets try to actually write the data */
	s->s2->wpend_tot=olen;
	s->s2->wpend_buf=buf;

	s->s2->wpend_ret=len;

	s->s2->wpend_off=0;
	return(write_pending(s,buf,olen));
	}

int ssl2_part_read(SSL *s, unsigned long f, int i)
	{
	unsigned char *p;
	int j;

	if (i < 0)
		{
		/* ssl2_return_error(s); */
		/* for non-blocking io,
		 * this is not necessarily fatal */
		return(i);
		}
	else
		{
		s->init_num+=i;

		/* Check for error.  While there are recoverable errors,
		 * this function is not called when those must be expected;
		 * any error detected here is fatal. */
		if (s->init_num >= 3)
			{
			p=(unsigned char *)s->init_buf->data;
			if (p[0] == SSL2_MT_ERROR)
				{
				j=(p[1]<<8)|p[2];
				SSLerr((int)f,ssl_mt_error(j));
				s->init_num -= 3;
				if (s->init_num > 0)
					memmove(p, p+3, s->init_num);
				}
			}

		/* If it's not an error message, we have some error anyway --
		 * the message was shorter than expected.  This too is treated
		 * as fatal (at least if SSL_get_error is asked for its opinion). */
		return(0);
		}
	}

int ssl2_do_write(SSL *s)
	{
	int ret;

	ret=ssl2_write(s,&s->init_buf->data[s->init_off],s->init_num);
	if (ret == s->init_num)
		{
		if (s->msg_callback)
			s->msg_callback(1, s->version, 0, s->init_buf->data, (size_t)(s->init_off + s->init_num), s, s->msg_callback_arg);
		return(1);
		}
	if (ret < 0)
		return(-1);
	s->init_off+=ret;
	s->init_num-=ret;
	return(0);
	}

static int ssl_mt_error(int n)
	{
	int ret;

	switch (n)
		{
	case SSL2_PE_NO_CIPHER:
		ret=SSL_R_PEER_ERROR_NO_CIPHER;
		break;
	case SSL2_PE_NO_CERTIFICATE:
		ret=SSL_R_PEER_ERROR_NO_CERTIFICATE;
		break;
	case SSL2_PE_BAD_CERTIFICATE:
		ret=SSL_R_PEER_ERROR_CERTIFICATE;
		break;
	case SSL2_PE_UNSUPPORTED_CERTIFICATE_TYPE:
		ret=SSL_R_PEER_ERROR_UNSUPPORTED_CERTIFICATE_TYPE;
		break;
	default:
		ret=SSL_R_UNKNOWN_REMOTE_ERROR_TYPE;
		break;
		}
	return(ret);
	}
#else /* !OPENSSL_NO_SSL2 */

# if PEDANTIC
static void *dummy=&dummy;
# endif

#endif