opaque structs for 1.1.0 compatibility (#3109)

We're so close.
diff --git a/src/_cffi_src/openssl/evp.py b/src/_cffi_src/openssl/evp.py
index 1d6874d..a046f3b 100644
--- a/src/_cffi_src/openssl/evp.py
+++ b/src/_cffi_src/openssl/evp.py
@@ -12,7 +12,7 @@
 typedef ... EVP_CIPHER;
 typedef ... EVP_CIPHER_CTX;
 typedef ... EVP_MD;
-typedef struct { ...; } EVP_MD_CTX;
+typedef ... EVP_MD_CTX;
 
 typedef ... EVP_PKEY;
 typedef ... EVP_PKEY_CTX;
diff --git a/src/_cffi_src/openssl/ssl.py b/src/_cffi_src/openssl/ssl.py
index 0b81f15..6e59d85 100644
--- a/src/_cffi_src/openssl/ssl.py
+++ b/src/_cffi_src/openssl/ssl.py
@@ -133,24 +133,9 @@
 typedef ... SSL_METHOD;
 typedef ... SSL_CTX;
 
-typedef struct {
-    int master_key_length;
-    unsigned char master_key[...];
-    unsigned char sid_ctx[...];
-    ...;
-} SSL_SESSION;
+typedef ... SSL_SESSION;
 
-typedef struct {
-    unsigned char server_random[...];
-    unsigned char client_random[...];
-    ...;
-} SSL3_STATE;
-
-typedef struct {
-    SSL3_STATE *s3;
-    SSL_SESSION *session;
-    ...;
-} SSL;
+typedef ... SSL;
 
 static const long TLSEXT_NAMETYPE_host_name;
 
diff --git a/src/_cffi_src/openssl/x509.py b/src/_cffi_src/openssl/x509.py
index 8a8d7df..d3a97a2 100644
--- a/src/_cffi_src/openssl/x509.py
+++ b/src/_cffi_src/openssl/x509.py
@@ -30,39 +30,15 @@
 } X509_ALGOR;
 
 typedef ... X509_ATTRIBUTE;
-
-typedef struct {
-    X509_ALGOR *signature;
-    ...;
-} X509_CINF;
-
+typedef ... X509_CINF;
 typedef ... X509_EXTENSION;
 typedef ... X509_EXTENSIONS;
 typedef ... X509_REQ;
 typedef ... X509_REQ_INFO;
-
-typedef struct {
-    ASN1_INTEGER *serialNumber;
-    ASN1_TIME *revocationDate;
-    X509_EXTENSIONS *extensions;
-    ...;
-} X509_REVOKED;
-
-typedef struct {
-    Cryptography_STACK_OF_X509_REVOKED *revoked;
-    ...;
-} X509_CRL_INFO;
-
-typedef struct {
-    X509_CRL_INFO *crl;
-    ...;
-} X509_CRL;
-
-typedef struct {
-    X509_CINF *cert_info;
-    ASN1_BIT_STRING *signature;
-    ...;
-} X509;
+typedef ... X509_REVOKED;
+typedef ... X509_CRL_INFO;
+typedef ... X509_CRL;
+typedef ... X509;
 
 typedef ... NETSCAPE_SPKI;