Move init_buf and rwstate into SSL3_STATE.

This finally clears most of the SSL_clear special-cases.

Change-Id: I00fc240ccbf13f4290322845f585ca6f5786ad80
Reviewed-on: https://boringssl-review.googlesource.com/21947
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: Steven Valdez <svaldez@google.com>

ssl/ssl_lib.cc

diff --git a/ssl/ssl_lib.cc b/ssl/ssl_lib.cc
index c8e6c94..2fc6ffd 100644
--- a/ssl/ssl_lib.cc
+++ b/ssl/ssl_lib.cc
@@ -201,7 +201,7 @@
 void ssl_reset_error_state(SSL *ssl) {
   // Functions which use |SSL_get_error| must reset I/O and error state on
   // entry.
-  ssl->rwstate = SSL_NOTHING;
+  ssl->s3->rwstate = SSL_NOTHING;
   ERR_clear_error();
   ERR_clear_system_error();
 }
@@ -716,8 +716,6 @@
     goto err;
   }
 
-  ssl->rwstate = SSL_NOTHING;
-
   CRYPTO_new_ex_data(&ssl->ex_data);
 
   ssl->psk_identity_hint = NULL;
@@ -762,8 +760,6 @@
   BIO_free_all(ssl->rbio);
   BIO_free_all(ssl->wbio);
 
-  BUF_MEM_free(ssl->init_buf);
-
   // add extra stuff
   ssl_cipher_preference_list_free(ssl->cipher_list);
 
@@ -1240,7 +1236,7 @@
     return SSL_ERROR_SYSCALL;
   }
 
-  switch (ssl->rwstate) {
+  switch (ssl->s3->rwstate) {
     case SSL_PENDING_SESSION:
       return SSL_ERROR_PENDING_SESSION;
 
@@ -2294,7 +2290,7 @@
   return CRYPTO_get_ex_data(&ctx->ex_data, idx);
 }
 
-int SSL_want(const SSL *ssl) { return ssl->rwstate; }
+int SSL_want(const SSL *ssl) { return ssl->s3->rwstate; }
 
 void SSL_CTX_set_tmp_rsa_callback(SSL_CTX *ctx,
                                   RSA *(*cb)(SSL *ssl, int is_export,
@@ -2578,17 +2574,6 @@
     SSL_SESSION_up_ref(session.get());
   }
 
-  // TODO(davidben): Some state on |ssl| is reset both in |SSL_new| and
-  // |SSL_clear| because it is per-connection state rather than configuration
-  // state. Per-connection state should be on |ssl->s3| and |ssl->d1| so it is
-  // naturally reset at the right points between |SSL_new|, |SSL_clear|, and
-  // |ssl3_new|.
-
-  ssl->rwstate = SSL_NOTHING;
-
-  BUF_MEM_free(ssl->init_buf);
-  ssl->init_buf = NULL;
-
   // The ssl->d1->mtu is simultaneously configuration (preserved across
   // clear) and connection-specific state (gets reset).
   //