New option SSL_OP_NO_COMP to disable compression. New ctrls to set
maximum send fragment size. Allocate I/O buffers accordingly.
diff --git a/CHANGES b/CHANGES
index f220bbe..cc2d55f 100644
--- a/CHANGES
+++ b/CHANGES
@@ -4,6 +4,12 @@
Changes between 0.9.8a and 0.9.9 [xx XXX xxxx]
+ *) New option SSL_OP_NO_COMP to disable use of compression selectively
+ in SSL structures. New SSL ctrl to set maximum send fragment size.
+ Save memory by seeting the I/O buffer sizes dynamically instead of
+ using the maximum available value.
+ [Steve Henson]
+
*) New option -V for 'openssl ciphers'. This prints the ciphersuite code
in addition to the text details.
[Bodo Moeller]
diff --git a/apps/s_client.c b/apps/s_client.c
index 96ae832..efd8b06 100644
--- a/apps/s_client.c
+++ b/apps/s_client.c
@@ -450,6 +450,8 @@
off|=SSL_OP_NO_SSLv3;
else if (strcmp(*argv,"-no_ssl2") == 0)
off|=SSL_OP_NO_SSLv2;
+ else if (strcmp(*argv,"-no_comp") == 0)
+ { off|=SSL_OP_NO_COMPRESSION; }
else if (strcmp(*argv,"-serverpref") == 0)
off|=SSL_OP_CIPHER_SERVER_PREFERENCE;
else if (strcmp(*argv,"-cipher") == 0)
diff --git a/apps/s_server.c b/apps/s_server.c
index 8c6fcc2..27c0e43 100644
--- a/apps/s_server.c
+++ b/apps/s_server.c
@@ -754,6 +754,8 @@
{ off|=SSL_OP_NO_SSLv3; }
else if (strcmp(*argv,"-no_tls1") == 0)
{ off|=SSL_OP_NO_TLSv1; }
+ else if (strcmp(*argv,"-no_comp") == 0)
+ { off|=SSL_OP_NO_COMPRESSION; }
#ifndef OPENSSL_NO_SSL2
else if (strcmp(*argv,"-ssl2") == 0)
{ meth=SSLv2_server_method(); }
diff --git a/ssl/s23_clnt.c b/ssl/s23_clnt.c
index 045a953..3cbc642 100644
--- a/ssl/s23_clnt.c
+++ b/ssl/s23_clnt.c
@@ -349,7 +349,8 @@
p+=i;
/* COMPRESSION */
- if (s->ctx->comp_methods == NULL)
+ if ((s->options & SSL_OP_NO_COMPRESSION)
+ || !s->ctx->comp_methods)
j=0;
else
j=sk_SSL_COMP_num(s->ctx->comp_methods);
diff --git a/ssl/s3_both.c b/ssl/s3_both.c
index 2ecfbb7..09d72e5 100644
--- a/ssl/s3_both.c
+++ b/ssl/s3_both.c
@@ -589,16 +589,22 @@
int ssl3_setup_buffers(SSL *s)
{
unsigned char *p;
- unsigned int extra;
size_t len;
if (s->s3->rbuf.buf == NULL)
{
+ len = SSL3_RT_MAX_PLAIN_LENGTH
+ + SSL3_RT_MAX_ENCRYPTED_OVERHEAD
+ + SSL3_RT_HEADER_LENGTH;
if (s->options & SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER)
- extra=SSL3_RT_MAX_EXTRA;
- else
- extra=0;
- len = SSL3_RT_MAX_PACKET_SIZE + extra;
+ {
+ s->s3->init_extra = 1;
+ len += SSL3_RT_MAX_EXTRA;
+ }
+#ifndef OPENSSL_NO_COMP
+ if (!(s->options & SSL_OP_NO_COMPRESSION))
+ len += SSL3_RT_MAX_COMPRESSED_OVERHEAD;
+#endif
if ((p=OPENSSL_malloc(len)) == NULL)
goto err;
s->s3->rbuf.buf = p;
@@ -607,8 +613,16 @@
if (s->s3->wbuf.buf == NULL)
{
- len = SSL3_RT_MAX_PACKET_SIZE;
- len += SSL3_RT_HEADER_LENGTH + 256; /* extra space for empty fragment */
+ len = s->max_send_fragment
+ + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD
+ + SSL3_RT_HEADER_LENGTH;
+#ifndef OPENSSL_NO_COMP
+ if (!(s->options & SSL_OP_NO_COMPRESSION))
+ len += SSL3_RT_MAX_COMPRESSED_OVERHEAD;
+#endif
+ if (!(s->options & SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS))
+ len += SSL3_RT_HEADER_LENGTH
+ + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD;
if ((p=OPENSSL_malloc(len)) == NULL)
goto err;
s->s3->wbuf.buf = p;
diff --git a/ssl/s3_clnt.c b/ssl/s3_clnt.c
index cc9df91..7284c0a 100644
--- a/ssl/s3_clnt.c
+++ b/ssl/s3_clnt.c
@@ -588,7 +588,9 @@
#ifdef OPENSSL_NO_COMP
*(p++)=1;
#else
- if (s->ctx->comp_methods == NULL)
+
+ if ((s->options & SSL_OP_NO_COMPRESSION)
+ || !s->ctx->comp_methods)
j=0;
else
j=sk_SSL_COMP_num(s->ctx->comp_methods);
@@ -768,7 +770,7 @@
}
#else
j= *(p++);
- if (j == 0)
+ if ((j == 0) || (s->options & SSL_OP_NO_COMPRESSION))
comp=NULL;
else
comp=ssl3_comp_find(s->ctx->comp_methods,j);
diff --git a/ssl/s3_pkt.c b/ssl/s3_pkt.c
index d0f54e2..fc913c2 100644
--- a/ssl/s3_pkt.c
+++ b/ssl/s3_pkt.c
@@ -250,9 +250,9 @@
extra=SSL3_RT_MAX_EXTRA;
else
extra=0;
- if (extra != s->s3->rbuf.len - SSL3_RT_MAX_PACKET_SIZE)
+ if (extra && !s->s3->init_extra)
{
- /* actually likely an application error: SLS_OP_MICROSOFT_BIG_SSLV3_BUFFER
+ /* An application error: SLS_OP_MICROSOFT_BIG_SSLV3_BUFFER
* set after ssl3_setup_buffers() was done */
SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
return -1;
@@ -275,6 +275,9 @@
ssl_minor= *(p++);
version=(ssl_major<<8)|ssl_minor;
n2s(p,rr->length);
+#if 0
+fprintf(stderr, "Record type=%d, Length=%d\n", rr->type, rr->length);
+#endif
/* Lets check version */
if (s->first_packet)
@@ -300,7 +303,7 @@
goto err;
}
- if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH+extra)
+ if (rr->length > s->s3->rbuf.len - SSL3_RT_HEADER_LENGTH)
{
al=SSL_AD_RECORD_OVERFLOW;
SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
@@ -466,6 +469,10 @@
/* just read a 0 length packet */
if (rr->length == 0) goto again;
+#if 0
+fprintf(stderr, "Ultimate Record type=%d, Length=%d\n", rr->type, rr->length);
+#endif
+
return(1);
f_err:
@@ -539,8 +546,8 @@
n=(len-tot);
for (;;)
{
- if (n > SSL3_RT_MAX_PLAIN_LENGTH)
- nw=SSL3_RT_MAX_PLAIN_LENGTH;
+ if (n > s->max_send_fragment)
+ nw=s->max_send_fragment;
else
nw=n;
@@ -624,7 +631,8 @@
if (prefix_len <= 0)
goto err;
- if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
+ if (prefix_len >
+ (SSL3_RT_HEADER_LENGTH + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD))
{
/* insufficient space */
SSLerr(SSL_F_DO_SSL3_WRITE, ERR_R_INTERNAL_ERROR);
diff --git a/ssl/s3_srvr.c b/ssl/s3_srvr.c
index 775bac3..96a2602 100644
--- a/ssl/s3_srvr.c
+++ b/ssl/s3_srvr.c
@@ -900,7 +900,7 @@
* algorithms from the client, starting at q. */
s->s3->tmp.new_compression=NULL;
#ifndef OPENSSL_NO_COMP
- if (s->ctx->comp_methods != NULL)
+ if (!(s->options & SSL_OP_NO_COMPRESSION) && s->ctx->comp_methods)
{ /* See if we have a match */
int m,nn,o,v,done=0;
diff --git a/ssl/ssl.h b/ssl/ssl.h
index f06b069..120c7a3 100644
--- a/ssl/ssl.h
+++ b/ssl/ssl.h
@@ -503,6 +503,8 @@
/* As server, disallow session resumption on renegotiation */
#define SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION 0x00010000L
+/* Don't use compression even if supported */
+#define SSL_OP_NO_COMPRESSION 0x00020000L
/* If set, always create a new key when using tmp_ecdh parameters */
#define SSL_OP_SINGLE_ECDH_USE 0x00080000L
/* If set, always create a new key when using tmp_dh parameters */
@@ -747,6 +749,12 @@
#endif
int quiet_shutdown;
+
+ /* Maximum amount of data to send in one fragment.
+ * actual record size can be more than this due to
+ * padding and MAC overheads.
+ */
+ int max_send_fragment;
};
#define SSL_SESS_CACHE_OFF 0x0000
@@ -968,6 +976,7 @@
int first_packet;
int client_version; /* what was passed, used for
* SSLv3/TLS rollback check */
+ int max_send_fragment;
};
#ifdef __cplusplus
@@ -1171,6 +1180,8 @@
#define SSL_CTRL_GET_MAX_CERT_LIST 50
#define SSL_CTRL_SET_MAX_CERT_LIST 51
+#define SSL_CTRL_SET_MAX_SEND_FRAGMENT 52
+
#define SSL_session_reused(ssl) \
SSL_ctrl((ssl),SSL_CTRL_GET_SESSION_REUSED,0,NULL)
#define SSL_num_renegotiations(ssl) \
@@ -1492,6 +1503,11 @@
#define SSL_set_max_cert_list(ssl,m) \
SSL_ctrl(ssl,SSL_CTRL_SET_MAX_CERT_LIST,m,NULL)
+#define SSL_CTX_set_max_send_fragment(ctx,m) \
+ SSL_CTX_ctrl(ctx,SSL_CTRL_SET_MAX_SEND_FRAGMENT,m,NULL)
+#define SSL_set_max_send_fragment(ssl,m) \
+ SSL_ctrl(ssl,SSL_CTRL_SET_MAX_SEND_FRAGMENT,m,NULL)
+
/* NB: the keylength is only applicable when is_export is true */
#ifndef OPENSSL_NO_RSA
void SSL_CTX_set_tmp_rsa_callback(SSL_CTX *ctx,
diff --git a/ssl/ssl3.h b/ssl/ssl3.h
index f0fbf82..2c6c79b 100644
--- a/ssl/ssl3.h
+++ b/ssl/ssl3.h
@@ -244,6 +244,18 @@
#define SSL3_SESSION_ID_SIZE 32
#define SSL3_RT_HEADER_LENGTH 5
+/* This is the maximum MAC (digest) size used by the SSL library.
+ * Currently this is 20 when SHA1 is used. This must be updated if larger
+ * digests are used in future.
+ */
+
+#define SSL3_RT_MAX_MD_SIZE 20
+
+/* Maximum block size used in all ciphersuites. Currently 16 for AES.
+ */
+
+#define SSL_RT_MAX_CIPHER_BLOCK_SIZE 16
+
/* Due to MS stuffing up, this can change.... */
#if defined(OPENSSL_SYS_WIN16) || \
(defined(OPENSSL_SYS_MSDOS) && !defined(OPENSSL_SYS_WIN32))
@@ -252,14 +264,36 @@
#define SSL3_RT_MAX_EXTRA (16384)
#endif
+/* Maximum plaintext length: defined by SSL/TLS standards */
#define SSL3_RT_MAX_PLAIN_LENGTH 16384
+/* Maximum compression overhead: defined by SSL/TLS standards */
+#define SSL3_RT_MAX_COMPRESSED_OVERHEAD 1024
+
+/* The standards give a maximum encryption overhead of 1024 bytes.
+ * In practice the value is lower than this. The overhead is the maximum
+ * number of padding bytes (256) plus the mac size.
+ */
+#define SSL3_RT_MAX_ENCRYPTED_OVERHEAD (256 + SSL3_RT_MAX_MD_SIZE)
+
+/* OpenSSL currently only uses a padding length of at most one block so
+ * the send overhead is smaller.
+ */
+
+#define SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD \
+ (SSL_RT_MAX_CIPHER_BLOCK_SIZE + SSL3_RT_MAX_MD_SIZE)
+
+/* If compression isn't used don't include the compression overhead */
+
#ifdef OPENSSL_NO_COMP
-#define SSL3_RT_MAX_COMPRESSED_LENGTH SSL3_RT_MAX_PLAIN_LENGTH
+#define SSL3_RT_MAX_COMPRESSED_LENGTH SSL3_RT_MAX_PLAIN_LENGTH
#else
-#define SSL3_RT_MAX_COMPRESSED_LENGTH (1024+SSL3_RT_MAX_PLAIN_LENGTH)
+#define SSL3_RT_MAX_COMPRESSED_LENGTH \
+ (SSL3_RT_MAX_PLAIN_LENGTH+SSL3_RT_MAX_COMPRESSED_OVERHEAD)
#endif
-#define SSL3_RT_MAX_ENCRYPTED_LENGTH (1024+SSL3_RT_MAX_COMPRESSED_LENGTH)
-#define SSL3_RT_MAX_PACKET_SIZE (SSL3_RT_MAX_ENCRYPTED_LENGTH+SSL3_RT_HEADER_LENGTH)
+#define SSL3_RT_MAX_ENCRYPTED_LENGTH \
+ (SSL3_RT_MAX_ENCRYPTED_OVERHEAD+SSL3_RT_MAX_COMPRESSED_LENGTH)
+#define SSL3_RT_MAX_PACKET_SIZE \
+ (SSL3_RT_MAX_ENCRYPTED_LENGTH+SSL3_RT_HEADER_LENGTH)
#define SSL3_RT_MAX_DATA_SIZE (1024*1024)
#define SSL3_MD_CLIENT_FINISHED_CONST "\x43\x4C\x4E\x54"
@@ -347,6 +381,9 @@
int need_empty_fragments;
int empty_fragment_done;
+ /* The value of 'extra' when the buffers were initialized */
+ int init_extra;
+
SSL3_BUFFER rbuf; /* read IO goes into here */
SSL3_BUFFER wbuf; /* write IO goes into here */
diff --git a/ssl/ssl_lib.c b/ssl/ssl_lib.c
index 6fb9364..f524f63 100644
--- a/ssl/ssl_lib.c
+++ b/ssl/ssl_lib.c
@@ -303,6 +303,7 @@
s->trust = ctx->trust;
#endif
s->quiet_shutdown=ctx->quiet_shutdown;
+ s->max_send_fragment = ctx->max_send_fragment;
CRYPTO_add(&ctx->references,1,CRYPTO_LOCK_SSL_CTX);
s->ctx=ctx;
@@ -973,6 +974,11 @@
return larg;
}
return 0;
+ case SSL_CTRL_SET_MAX_SEND_FRAGMENT:
+ if (larg < 512 || larg > SSL3_RT_MAX_PLAIN_LENGTH)
+ return 0;
+ s->max_send_fragment = larg;
+ return 1;
default:
return(s->method->ssl_ctrl(s,cmd,larg,parg));
}
@@ -1061,6 +1067,11 @@
return(ctx->options|=larg);
case SSL_CTRL_MODE:
return(ctx->mode|=larg);
+ case SSL_CTRL_SET_MAX_SEND_FRAGMENT:
+ if (larg < 512 || larg > SSL3_RT_MAX_PLAIN_LENGTH)
+ return 0;
+ ctx->max_send_fragment = larg;
+ return 1;
default:
return(ctx->method->ssl_ctx_ctrl(ctx,cmd,larg,parg));
}
@@ -1453,6 +1464,8 @@
ret->extra_certs=NULL;
ret->comp_methods=SSL_COMP_get_compression_methods();
+ ret->max_send_fragment = SSL3_RT_MAX_PLAIN_LENGTH;
+
return(ret);
err:
SSLerr(SSL_F_SSL_CTX_NEW,ERR_R_MALLOC_FAILURE);
