Partially revert "Detect EOF while reading in libssl"

This partially reverts commit db943f43.
Reviewed-by: NMatt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/11400)

crypto/err/openssl.txt

@@ -2852,7 +2852,6 @@ SSL_R_UNABLE_TO_LOAD_SSL3_MD5_ROUTINES:242:unable to load ssl3 md5 routines
 SSL_R_UNABLE_TO_LOAD_SSL3_SHA1_ROUTINES:243:unable to load ssl3 sha1 routines
 SSL_R_UNEXPECTED_CCS_MESSAGE:262:unexpected ccs message
 SSL_R_UNEXPECTED_END_OF_EARLY_DATA:178:unexpected end of early data
-SSL_R_UNEXPECTED_EOF_WHILE_READING:294:unexpected eof while reading
 SSL_R_UNEXPECTED_MESSAGE:244:unexpected message
 SSL_R_UNEXPECTED_RECORD:245:unexpected record
 SSL_R_UNINITIALIZED:276:uninitialized

include/openssl/sslerr.h

 /*
  * Generated by util/mkerr.pl DO NOT EDIT
- * Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 1995-2019 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the OpenSSL license (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
@@ -734,7 +734,6 @@ int ERR_load_SSL_strings(void);
 # define SSL_R_UNABLE_TO_LOAD_SSL3_SHA1_ROUTINES          243
 # define SSL_R_UNEXPECTED_CCS_MESSAGE                     262
 # define SSL_R_UNEXPECTED_END_OF_EARLY_DATA               178
-# define SSL_R_UNEXPECTED_EOF_WHILE_READING               294
 # define SSL_R_UNEXPECTED_MESSAGE                         244
 # define SSL_R_UNEXPECTED_RECORD                          245
 # define SSL_R_UNINITIALIZED                              276

ssl/record/rec_layer_s3.c

@@ -296,12 +296,6 @@ int ssl3_read_n(SSL *s, size_t n, size_t max, int extend, int clearold,
             ret = BIO_read(s->rbio, pkt + len + left, max - left);
             if (ret >= 0)
                 bioread = ret;
-            if (ret <= 0
-                    && !BIO_should_retry(s->rbio)
-                    && BIO_eof(s->rbio)) {
-                SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_READ_N,
-                         SSL_R_UNEXPECTED_EOF_WHILE_READING);
-            }
         } else {
             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_READ_N,
                      SSL_R_READ_BIO_NOT_SET);

ssl/ssl_err.c

 /*
  * Generated by util/mkerr.pl DO NOT EDIT
- * Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 1995-2019 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the OpenSSL license (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
@@ -1205,8 +1205,6 @@ static const ERR_STRING_DATA SSL_str_reasons[] = {
     "unexpected ccs message"},
     {ERR_PACK(ERR_LIB_SSL, 0, SSL_R_UNEXPECTED_END_OF_EARLY_DATA),
     "unexpected end of early data"},
-    {ERR_PACK(ERR_LIB_SSL, 0, SSL_R_UNEXPECTED_EOF_WHILE_READING),
-    "unexpected eof while reading"},
     {ERR_PACK(ERR_LIB_SSL, 0, SSL_R_UNEXPECTED_MESSAGE), "unexpected message"},
     {ERR_PACK(ERR_LIB_SSL, 0, SSL_R_UNEXPECTED_RECORD), "unexpected record"},
     {ERR_PACK(ERR_LIB_SSL, 0, SSL_R_UNINITIALIZED), "uninitialized"},