廢話不多說，直接上問題：
PHP和openssl extension都是最新版本的，標准步驟安裝時候出現如下問題：
php：php-5.6.27
openssl：openssl-1.1.0e
================================
/root/software/php/php-5.6.27/ext/openssl/openssl.c:3536:31: error: dereferencing pointer to incomplete type
int len = BN_num_bytes(pkey->pkey._type->_name); \
^
/usr/local/openssl/include/openssl/bn.h:142:40: note: in definition of macro ‘BN_num_bytes’
# define BN_num_bytes(a) ((BN_num_bits(a)+7)/8)
^
/root/software/php/php-5.6.27/ext/openssl/openssl.c:3982:5: note: in expansion of macro ‘OPENSSL_PKEY_GET_BN’
OPENSSL_PKEY_GET_BN(dh, g);
^
/root/software/php/php-5.6.27/ext/openssl/openssl.c:3538:18: error: dereferencing pointer to incomplete type
BN_bn2bin(pkey->pkey._type->_name, (unsigned char*)str); \
^
/root/software/php/php-5.6.27/ext/openssl/openssl.c:3982:5: note: in expansion of macro ‘OPENSSL_PKEY_GET_BN’
OPENSSL_PKEY_GET_BN(dh, g);
^
/root/software/php/php-5.6.27/ext/openssl/openssl.c:3535:11: error: dereferencing pointer to incomplete type
if (pkey->pkey._type->_name != NULL) { \
^
/root/software/php/php-5.6.27/ext/openssl/openssl.c:3983:5: note: in expansion of macro ‘OPENSSL_PKEY_GET_BN’
OPENSSL_PKEY_GET_BN(dh, priv_key);
^
In file included from /usr/local/openssl/include/openssl/asn1.h:24:0,
from /usr/local/openssl/include/openssl/objects.h:916,
from /usr/local/openssl/include/openssl/evp.h:27,
from /root/software/php/php-5.6.27/ext/openssl/openssl.c:44:
/root/software/php/php-5.6.27/ext/openssl/openssl.c:3536:31: error: dereferencing pointer to incomplete type
int len = BN_num_bytes(pkey->pkey._type->_name); \
^
/usr/local/openssl/include/openssl/bn.h:142:40: note: in definition of macro ‘BN_num_bytes’
# define BN_num_bytes(a) ((BN_num_bits(a)+7)/8)
^
/root/software/php/php-5.6.27/ext/openssl/openssl.c:3983:5: note: in expansion of macro ‘OPENSSL_PKEY_GET_BN’
OPENSSL_PKEY_GET_BN(dh, priv_key);
^
/root/software/php
================================
在網上搜索了一圈，都沒有答案。
於是打開代碼看來一下，看來某些定義的頭文件沒有引用進來。
但如本人才疏學淺，對openssl沒有整體的把握，所以就對比了之前的openssl版本，發現版本升級后，代碼是有變化的。
具體細節大家可以自己去看。
解決辦法就是：
把openssl的版本降級，我選擇的是openssl-0.9.8v。
重新編譯安裝，就不會有編譯錯誤了。