#include <stdio.h>
#include <errno.h>
#define USE_SOCKETS
+#include "ssl_locl.h"
#include <openssl/evp.h>
#include <openssl/buffer.h>
-#include "ssl_locl.h"
static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
unsigned int len, int create_empty_fragment);
-static int ssl3_write_pending(SSL *s, int type, const unsigned char *buf,
- unsigned int len);
static int ssl3_get_record(SSL *s);
-static int do_compress(SSL *ssl);
-static int do_uncompress(SSL *ssl);
-static int do_change_cipher_spec(SSL *ssl);
-/* used only by ssl3_get_record */
-static int ssl3_read_n(SSL *s, int n, int max, int extend)
+int ssl3_read_n(SSL *s, int n, int max, int extend)
{
/* If extend == 0, obtain new n-byte packet; if extend == 1, increase
* packet by another n bytes.
/* ... now we can act as if 'extend' was set */
}
+ /* extend reads should not span multiple packets for DTLS */
+ if ( SSL_version(s) == DTLS1_VERSION &&
+ extend)
+ {
+ if ( s->s3->rbuf.left > 0 && n > s->s3->rbuf.left)
+ n = s->s3->rbuf.left;
+ }
+
/* if there is enough in the buffer from a previous read, take some */
if (s->s3->rbuf.left >= (int)n)
{
unsigned char md[EVP_MAX_MD_SIZE];
short version;
unsigned int mac_size;
- int clear=0,extra;
+ int clear=0;
+ size_t extra;
+ int decryption_failed_or_bad_record_mac = 0;
+ unsigned char *mac = NULL;
rr= &(s->s3->rrec);
sess=s->session;
extra=SSL3_RT_MAX_EXTRA;
else
extra=0;
- if (extra != (s->s3->rbuf.len - SSL3_RT_MAX_PACKET_SIZE))
+ if (extra != s->s3->rbuf.len - SSL3_RT_MAX_PACKET_SIZE)
{
/* actually likely an application error: SLS_OP_MICROSOFT_BIG_SSLV3_BUFFER
* set after ssl3_setup_buffers() was done */
goto err;
}
- if (rr->length >
- (unsigned int)SSL3_RT_MAX_ENCRYPTED_LENGTH+extra)
+ if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH+extra)
{
al=SSL_AD_RECORD_OVERFLOW;
SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
/* s->rstate == SSL_ST_READ_BODY, get and decode the data */
- if (rr->length > (s->packet_length-SSL3_RT_HEADER_LENGTH))
+ if (rr->length > s->packet_length-SSL3_RT_HEADER_LENGTH)
{
/* now s->packet_length == SSL3_RT_HEADER_LENGTH */
i=rr->length;
* rr->length bytes of encrypted compressed stuff. */
/* check is not needed I believe */
- if (rr->length > (unsigned int)SSL3_RT_MAX_ENCRYPTED_LENGTH+extra)
+ if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH+extra)
{
al=SSL_AD_RECORD_OVERFLOW;
SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
/* SSLerr() and ssl3_send_alert() have been called */
goto err;
- /* otherwise enc_err == -1 */
- goto decryption_failed_or_bad_record_mac;
+ /* Otherwise enc_err == -1, which indicates bad padding
+ * (rec->length has not been changed in this case).
+ * To minimize information leaked via timing, we will perform
+ * the MAC computation anyway. */
+ decryption_failed_or_bad_record_mac = 1;
}
#ifdef TLS_DEBUG
SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
goto f_err;
#else
- goto decryption_failed_or_bad_record_mac;
+ decryption_failed_or_bad_record_mac = 1;
#endif
}
/* check the MAC for rr->input (it's in mac_size bytes at the tail) */
- if (rr->length < mac_size)
+ if (rr->length >= mac_size)
+ {
+ rr->length -= mac_size;
+ mac = &rr->data[rr->length];
+ }
+ else
{
+ /* record (minus padding) is too short to contain a MAC */
#if 0 /* OK only for stream ciphers */
al=SSL_AD_DECODE_ERROR;
SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_LENGTH_TOO_SHORT);
goto f_err;
#else
- goto decryption_failed_or_bad_record_mac;
+ decryption_failed_or_bad_record_mac = 1;
+ rr->length = 0;
#endif
}
- rr->length-=mac_size;
i=s->method->ssl3_enc->mac(s,md,0);
- if (memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
+ if (mac == NULL || memcmp(md, mac, mac_size) != 0)
{
- goto decryption_failed_or_bad_record_mac;
+ decryption_failed_or_bad_record_mac = 1;
}
}
+ if (decryption_failed_or_bad_record_mac)
+ {
+ /* A separate 'decryption_failed' alert was introduced with TLS 1.0,
+ * SSL 3.0 only has 'bad_record_mac'. But unless a decryption
+ * failure is directly visible from the ciphertext anyway,
+ * we should not reveal which kind of error occured -- this
+ * might become visible to an attacker (e.g. via a logfile) */
+ al=SSL_AD_BAD_RECORD_MAC;
+ SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
+ goto f_err;
+ }
+
/* r->length is now just compressed */
if (s->expand != NULL)
{
- if (rr->length >
- (unsigned int)SSL3_RT_MAX_COMPRESSED_LENGTH+extra)
+ if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra)
{
al=SSL_AD_RECORD_OVERFLOW;
SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
goto f_err;
}
- if (!do_uncompress(s))
+ if (!ssl3_do_uncompress(s))
{
al=SSL_AD_DECOMPRESSION_FAILURE;
SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_BAD_DECOMPRESSION);
}
}
- if (rr->length > (unsigned int)SSL3_RT_MAX_PLAIN_LENGTH+extra)
+ if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH+extra)
{
al=SSL_AD_RECORD_OVERFLOW;
SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
return(1);
-decryption_failed_or_bad_record_mac:
- /* Separate 'decryption_failed' alert was introduced with TLS 1.0,
- * SSL 3.0 only has 'bad_record_mac'. But unless a decryption
- * failure is directly visible from the ciphertext anyway,
- * we should not reveal which kind of error occured -- this
- * might become visible to an attacker (e.g. via logfile) */
- al=SSL_AD_BAD_RECORD_MAC;
- SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
f_err:
ssl3_send_alert(s,SSL3_AL_FATAL,al);
err:
return(ret);
}
-static int do_uncompress(SSL *ssl)
+int ssl3_do_uncompress(SSL *ssl)
{
int i;
SSL3_RECORD *rr;
return(1);
}
-static int do_compress(SSL *ssl)
+int ssl3_do_compress(SSL *ssl)
{
int i;
SSL3_RECORD *wr;
/* If we have an alert to send, lets send it */
if (s->s3->alert_dispatch)
{
- i=ssl3_dispatch_alert(s);
+ i=s->method->ssl_dispatch_alert(s);
if (i <= 0)
return(i);
/* if it went, fall through and send more stuff */
if (prefix_len <= 0)
goto err;
- if (s->s3->wbuf.len < prefix_len + SSL3_RT_MAX_PACKET_SIZE)
+ if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
{
/* insufficient space */
SSLerr(SSL_F_DO_SSL3_WRITE, ERR_R_INTERNAL_ERROR);
/* first we compress */
if (s->compress != NULL)
{
- if (!do_compress(s))
+ if (!ssl3_do_compress(s))
{
SSLerr(SSL_F_DO_SSL3_WRITE,SSL_R_COMPRESSION_FAILURE);
goto err;
}
/* if s->s3->wbuf.left != 0, we need to call this */
-static int ssl3_write_pending(SSL *s, int type, const unsigned char *buf,
- unsigned int len)
+int ssl3_write_pending(SSL *s, int type, const unsigned char *buf,
+ unsigned int len)
{
int i;
{
al=SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
- goto err;
+ goto f_err;
}
/* If the other end has shut down, throw anything we read away
{
al=SSL_AD_DECODE_ERROR;
SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
- goto err;
+ goto f_err;
}
if (s->msg_callback)
if ( (rr->length != 1) || (rr->off != 0) ||
(rr->data[0] != SSL3_MT_CCS))
{
- i=SSL_AD_ILLEGAL_PARAMETER;
+ al=SSL_AD_ILLEGAL_PARAMETER;
SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
- goto err;
+ goto f_err;
+ }
+
+ /* Check we have a cipher to change to */
+ if (s->s3->tmp.new_cipher == NULL)
+ {
+ al=SSL_AD_UNEXPECTED_MESSAGE;
+ SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_CCS_RECEIVED_EARLY);
+ goto f_err;
}
rr->length=0;
s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, 1, s, s->msg_callback_arg);
s->s3->change_cipher_spec=1;
- if (!do_change_cipher_spec(s))
+ if (!ssl3_do_change_cipher_spec(s))
goto err;
else
goto start;
return(-1);
}
-static int do_change_cipher_spec(SSL *s)
+int ssl3_do_change_cipher_spec(SSL *s)
{
int i;
const char *sender;
s->s3->send_alert[0]=level;
s->s3->send_alert[1]=desc;
if (s->s3->wbuf.left == 0) /* data still being written out? */
- ssl3_dispatch_alert(s);
+ s->method->ssl_dispatch_alert(s);
/* else data is still being written out, we will get written
* some time in the future */
}