Fix support for LibreSSL versions other than 2.5.0

1 files changed, 544 insertions, 0 deletions

diff --git a/openssl-sys/src/libressl/mod.rs b/openssl-sys/src/libressl/mod.rs
new file mode 100644
index 00000000..951ab4d3
--- /dev/null
+++ b/openssl-sys/src/libressl/mod.rs
@@ -0,0 +1,544 @@
+use std::sync::{Mutex, MutexGuard};
+use std::sync::{Once, ONCE_INIT};
+use std::mem;
+use std::ptr;
+
+#[cfg(libressl250)]
+pub use libressl::v250::*;
+#[cfg(not(libressl250))]
+pub use libressl::v25x::*;
+
+use libc::{c_int, c_char, c_void, c_long, c_uchar, size_t, c_uint, c_ulong};
+
+#[cfg(libressl250)]
+mod v250;
+#[cfg(not(libressl250))]
+mod v25x;
+
+#[repr(C)]
+pub struct stack_st_ASN1_OBJECT {
+    pub stack: _STACK,
+}
+
+#[repr(C)]
+pub struct stack_st_X509 {
+    pub stack: _STACK,
+}
+
+#[repr(C)]
+pub struct stack_st_X509_NAME {
+    pub stack: _STACK,
+}
+
+#[repr(C)]
+pub struct stack_st_X509_ATTRIBUTE {
+    pub stack: _STACK,
+}
+
+#[repr(C)]
+pub struct stack_st_X509_EXTENSION {
+    pub stack: _STACK,
+}
+
+#[repr(C)]
+pub struct stack_st_GENERAL_NAME {
+    pub stack: _STACK,
+}
+
+#[repr(C)]
+pub struct stack_st_void {
+    pub stack: _STACK,
+}
+
+#[repr(C)]
+pub struct stack_st_SSL_CIPHER {
+    pub stack: _STACK,
+}
+
+#[repr(C)]
+pub struct stack_st_OPENSSL_STRING {
+    pub stack: _STACK,
+}
+
+#[repr(C)]
+pub struct _STACK {
+    pub num: c_int,
+    pub data: *mut *mut c_char,
+    pub sorted: c_int,
+    pub num_alloc: c_int,
+    pub comp: Option<unsafe extern fn(*const c_void, *const c_void) -> c_int>,
+}
+
+#[repr(C)]
+pub struct BIO_METHOD {
+    pub type_: c_int,
+    pub name: *const c_char,
+    pub bwrite: Option<unsafe extern fn(*mut ::BIO, *const c_char, c_int) -> c_int>,
+    pub bread: Option<unsafe extern fn(*mut ::BIO, *mut c_char, c_int) -> c_int>,
+    pub bputs: Option<unsafe extern fn(*mut ::BIO, *const c_char) -> c_int>,
+    pub bgets: Option<unsafe extern fn(*mut ::BIO, *mut c_char, c_int) -> c_int>,
+    pub ctrl: Option<unsafe extern fn(*mut ::BIO, c_int, c_long, *mut c_void) -> c_long>,
+    pub create: Option<unsafe extern fn(*mut ::BIO) -> c_int>,
+    pub destroy: Option<unsafe extern fn(*mut ::BIO) -> c_int>,
+    pub callback_ctrl: Option<unsafe extern fn(*mut ::BIO, c_int, ::bio_info_cb) -> c_long>,
+}
+
+#[repr(C)]
+pub struct RSA {
+    pub pad: c_int,
+    pub version: c_long,
+    pub meth: *const ::RSA_METHOD,
+
+    pub engine: *mut ::ENGINE,
+    pub n: *mut ::BIGNUM,
+    pub e: *mut ::BIGNUM,
+    pub d: *mut ::BIGNUM,
+    pub p: *mut ::BIGNUM,
+    pub q: *mut ::BIGNUM,
+    pub dmp1: *mut ::BIGNUM,
+    pub dmq1: *mut ::BIGNUM,
+    pub iqmp: *mut ::BIGNUM,
+
+    pub ex_data: ::CRYPTO_EX_DATA,
+    pub references: c_int,
+    pub flags: c_int,
+
+    pub _method_mod_n: *mut ::BN_MONT_CTX,
+    pub _method_mod_p: *mut ::BN_MONT_CTX,
+    pub _method_mod_q: *mut ::BN_MONT_CTX,
+
+    pub blinding: *mut ::BN_BLINDING,
+    pub mt_blinding: *mut ::BN_BLINDING,
+}
+
+#[repr(C)]
+pub struct DSA {
+    pub pad: c_int,
+    pub version: c_long,
+    pub write_params: c_int,
+
+    pub p: *mut ::BIGNUM,
+    pub q: *mut ::BIGNUM,
+    pub g: *mut ::BIGNUM,
+    pub pub_key: *mut ::BIGNUM,
+    pub priv_key: *mut ::BIGNUM,
+    pub kinv: *mut ::BIGNUM,
+    pub r: *mut ::BIGNUM,
+
+    pub flags: c_int,
+    pub method_mont_p: *mut ::BN_MONT_CTX,
+    pub references: c_int,
+    pub ex_data: ::CRYPTO_EX_DATA,
+    pub meth: *const ::DSA_METHOD,
+    pub engine: *mut ::ENGINE,
+}
+
+#[repr(C)]
+pub struct EVP_PKEY {
+    pub type_: c_int,
+    pub save_type: c_int,
+    pub references: c_int,
+    pub ameth: *const ::EVP_PKEY_ASN1_METHOD,
+    pub engine: *mut ::ENGINE,
+    pub pkey: *mut c_void,
+    pub save_parameters: c_int,
+    pub attributes: *mut stack_st_X509_ATTRIBUTE,
+}
+
+#[repr(C)]
+pub struct BIO {
+    pub method: *mut ::BIO_METHOD,
+    pub callback: Option<unsafe extern fn(*mut ::BIO,
+                                              c_int,
+                                              *const c_char,
+                                              c_int,
+                                              c_long,
+                                              c_long)
+                                              -> c_long>,
+    pub cb_arg: *mut c_char,
+    pub init: c_int,
+    pub shutdown: c_int,
+    pub flags: c_int,
+    pub retry_reason: c_int,
+    pub num: c_int,
+    pub ptr: *mut c_void,
+    pub next_bio: *mut ::BIO,
+    pub prev_bio: *mut ::BIO,
+    pub references: c_int,
+    pub num_read: c_ulong,
+    pub num_write: c_ulong,
+    pub ex_data: ::CRYPTO_EX_DATA,
+}
+
+#[repr(C)]
+pub struct CRYPTO_EX_DATA {
+    pub sk: *mut ::stack_st_void,
+}
+
+#[repr(C)]
+pub struct EVP_MD_CTX {
+    digest: *mut ::EVP_MD,
+    engine: *mut ::ENGINE,
+    flags: c_ulong,
+    md_data: *mut c_void,
+    pctx: *mut ::EVP_PKEY_CTX,
+    update: *mut c_void
+}
+
+#[repr(C)]
+pub struct EVP_CIPHER {
+    pub nid: c_int,
+    pub block_size: c_int,
+    pub key_len: c_int,
+    pub iv_len: c_int,
+    pub flags: c_ulong,
+    pub init: Option<unsafe extern fn(*mut ::EVP_CIPHER_CTX,
+                                      *const c_uchar,
+                                      *const c_uchar,
+                                      c_int) -> c_int>,
+    pub do_cipher: Option<unsafe extern fn(*mut ::EVP_CIPHER_CTX,
+                                           *mut c_uchar,
+                                           *const c_uchar,
+                                           size_t) -> c_int>,
+    pub cleanup: Option<unsafe extern fn(*mut ::EVP_CIPHER_CTX) -> c_int>,
+    pub ctx_size: c_int,
+    pub set_asn1_parameters: Option<unsafe extern fn(*mut ::EVP_CIPHER_CTX,
+                                                     *mut ::ASN1_TYPE) -> c_int>,
+    pub get_asn1_parameters: Option<unsafe extern fn(*mut ::EVP_CIPHER_CTX,
+                                                     *mut ::ASN1_TYPE) -> c_int>,
+    pub ctrl: Option<unsafe extern fn(*mut ::EVP_CIPHER_CTX,
+                                      c_int,
+                                      c_int,
+                                      *mut c_void) -> c_int>,
+    pub app_data: *mut c_void,
+}
+
+#[repr(C)]
+pub struct HMAC_CTX {
+    md: *mut ::EVP_MD,
+    md_ctx: ::EVP_MD_CTX,
+    i_ctx: ::EVP_MD_CTX,
+    o_ctx: ::EVP_MD_CTX,
+    key_length: c_uint,
+    key: [c_uchar; 128]
+}
+
+#[repr(C)]
+pub struct BIGNUM {
+    pub d: *mut ::BN_ULONG,
+    pub top: c_int,
+    pub dmax: c_int,
+    pub neg: c_int,
+    pub flags: c_int,
+}
+
+#[repr(C)]
+pub struct DH {
+    pub pad: c_int,
+    pub version: c_int,
+    pub p: *mut ::BIGNUM,
+    pub g: *mut ::BIGNUM,
+    pub length: c_long,
+    pub pub_key: *mut ::BIGNUM,
+    pub priv_key: *mut ::BIGNUM,
+    pub flags: c_int,
+    pub method_mont_p: *mut ::BN_MONT_CTX,
+    pub q: *mut ::BIGNUM,
+    pub j: *mut ::BIGNUM,
+    pub seed: *mut c_uchar,
+    pub seedlen: c_int,
+    pub counter: *mut ::BIGNUM,
+    pub references: c_int,
+    pub ex_data: ::CRYPTO_EX_DATA,
+    pub meth: *const ::DH_METHOD,
+    pub engine: *mut ::ENGINE,
+}
+
+#[repr(C)]
+pub struct X509 {
+    pub cert_info: *mut X509_CINF,
+    pub sig_alg: *mut ::X509_ALGOR,
+    pub signature: *mut ::ASN1_BIT_STRING,
+    pub valid: c_int,
+    pub references: c_int,
+    pub name: *mut c_char,
+    pub ex_data: ::CRYPTO_EX_DATA,
+    pub ex_pathlen: c_long,
+    pub ex_pcpathlen: c_long,
+    pub ex_flags: c_ulong,
+    pub ex_kusage: c_ulong,
+    pub ex_xkusage: c_ulong,
+    pub ex_nscert: c_ulong,
+    skid: *mut c_void,
+    akid: *mut c_void,
+    policy_cache: *mut c_void,
+    crldp: *mut c_void,
+    altname: *mut c_void,
+    nc: *mut c_void,
+    #[cfg(not(osslconf = "OPENSSL_NO_SHA"))]
+    sha1_hash: [c_uchar; 20],
+    aux: *mut c_void,
+}
+
+#[repr(C)]
+pub struct X509_CINF {
+    version: *mut c_void,
+    serialNumber: *mut c_void,
+    signature: *mut c_void,
+    issuer: *mut c_void,
+    pub validity: *mut X509_VAL,
+    subject: *mut c_void,
+    key: *mut c_void,
+    issuerUID: *mut c_void,
+    subjectUID: *mut c_void,
+    pub extensions: *mut stack_st_X509_EXTENSION,
+    enc: ASN1_ENCODING,
+}
+
+#[repr(C)]
+pub struct X509_ALGOR {
+    pub algorithm: *mut ::ASN1_OBJECT,
+    parameter: *mut c_void,
+}
+
+#[repr(C)]
+pub struct ASN1_ENCODING {
+    pub enc: *mut c_uchar,
+    pub len: c_long,
+    pub modified: c_int,
+}
+
+#[repr(C)]
+pub struct X509_VAL {
+    pub notBefore: *mut ::ASN1_TIME,
+    pub notAfter: *mut ::ASN1_TIME,
+}
+
+#[repr(C)]
+pub struct X509_REQ_INFO {
+    pub enc: ASN1_ENCODING,
+    pub version: *mut ::ASN1_INTEGER,
+    pub subject: *mut ::X509_NAME,
+    pubkey: *mut c_void,
+    pub attributes: *mut stack_st_X509_ATTRIBUTE
+}
+
+#[repr(C)]
+pub struct X509_REQ {
+    pub req_info: *mut X509_REQ_INFO,
+    sig_alg: *mut c_void,
+    signature: *mut c_void,
+    references: c_int
+}
+
+pub enum X509_VERIFY_PARAM_ID {}
+pub enum PKCS12 {}
+
+pub const SSL_CTRL_GET_SESSION_REUSED: c_int = 8;
+pub const SSL_CTRL_OPTIONS: c_int = 32;
+pub const SSL_CTRL_CLEAR_OPTIONS: c_int = 77;
+pub const SSL_CTRL_SET_ECDH_AUTO: c_int = 94;
+
+pub const SSL_OP_ALL: c_ulong =                                     0x80000014;
+pub const SSL_OP_CISCO_ANYCONNECT: c_ulong =                        0x0;
+pub const SSL_OP_NO_COMPRESSION: c_ulong =                          0x0;
+pub const SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION: c_ulong =       0x0;
+pub const SSL_OP_NO_SSLv3: c_ulong =                                0x0;
+pub const SSL_OP_MICROSOFT_SESS_ID_BUG: c_ulong =                   0x0;
+pub const SSL_OP_NETSCAPE_CHALLENGE_BUG: c_ulong =                  0x0;
+pub const SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG: c_ulong =        0x0;
+pub const SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER: c_ulong =              0x0;
+pub const SSL_OP_SSLEAY_080_CLIENT_DH_BUG: c_ulong =                0x0;
+pub const SSL_OP_TLS_D5_BUG: c_ulong =                              0x0;
+pub const SSL_OP_TLS_BLOCK_PADDING_BUG: c_ulong =                   0x0;
+pub const SSL_OP_SINGLE_ECDH_USE: c_ulong =                         0x00080000;
+pub const SSL_OP_SINGLE_DH_USE: c_ulong =                           0x00100000;
+pub const SSL_OP_NO_SSLv2: c_ulong =                                0x0;
+
+pub const SSL_MAX_SSL_SESSION_ID_LENGTH: c_int = 32;
+pub const SSL_MAX_SID_CTX_LENGTH: c_int = 32;
+pub const SSL_MAX_MASTER_KEY_LENGTH: c_int = 48;
+
+pub const SSLEAY_VERSION : c_int = 0;
+pub const SSLEAY_CFLAGS : c_int = 2;
+pub const SSLEAY_BUILT_ON : c_int = 3;
+pub const SSLEAY_PLATFORM : c_int = 4;
+pub const SSLEAY_DIR : c_int = 5;
+
+pub const CRYPTO_LOCK_X509: c_int = 3;
+pub const CRYPTO_LOCK_SSL_CTX: c_int = 12;
+pub const CRYPTO_LOCK_SSL_SESSION: c_int = 14;
+
+static mut MUTEXES: *mut Vec<Mutex<()>> = 0 as *mut Vec<Mutex<()>>;
+static mut GUARDS: *mut Vec<Option<MutexGuard<'static, ()>>> = 0 as *mut Vec<Option<MutexGuard<'static, ()>>>;
+
+unsafe extern fn locking_function(mode: c_int, n: c_int, _file: *const c_char,
+                               _line: c_int) {
+    let mutex = &(*MUTEXES)[n as usize];
+
+    if mode & ::CRYPTO_LOCK != 0 {
+        (*GUARDS)[n as usize] = Some(mutex.lock().unwrap());
+    } else {
+        &(*GUARDS)[n as usize].take().expect("lock already unlocked");
+    }
+}
+
+pub fn init() {
+    static INIT: Once = ONCE_INIT;
+
+    INIT.call_once(|| {
+        unsafe {
+            SSL_library_init();
+            SSL_load_error_strings();
+            OPENSSL_add_all_algorithms_noconf();
+
+            let num_locks = ::CRYPTO_num_locks();
+            let mut mutexes = Box::new(Vec::new());
+            for _ in 0..num_locks {
+                mutexes.push(Mutex::new(()));
+            }
+            MUTEXES = mem::transmute(mutexes);
+            let guards: Box<Vec<Option<MutexGuard<()>>>> =
+                Box::new((0..num_locks).map(|_| None).collect());
+            GUARDS = mem::transmute(guards);
+
+            CRYPTO_set_locking_callback(locking_function);
+            set_id_callback();
+        }
+    })
+}
+
+#[cfg(unix)]
+fn set_id_callback() {
+    unsafe extern fn thread_id() -> c_ulong {
+        ::libc::pthread_self() as c_ulong
+    }
+
+    unsafe {
+        CRYPTO_set_id_callback(thread_id);
+    }
+}
+
+#[cfg(not(unix))]
+fn set_id_callback() {}
+
+// macros
+
+pub unsafe fn SSL_CTX_set_ecdh_auto(ctx: *mut SSL_CTX, onoff: c_int) -> c_int {
+    ::SSL_CTX_ctrl(ctx, SSL_CTRL_SET_ECDH_AUTO, onoff as c_long, ptr::null_mut()) as c_int
+}
+
+pub unsafe fn SSL_set_ecdh_auto(ssl: *mut ::SSL, onoff: c_int) -> c_int {
+    ::SSL_ctrl(ssl, SSL_CTRL_SET_ECDH_AUTO, onoff as c_long, ptr::null_mut()) as c_int
+}
+
+pub unsafe fn SSL_session_reused(ssl: *mut ::SSL) -> c_int {
+    ::SSL_ctrl(ssl, SSL_CTRL_GET_SESSION_REUSED, 0, ptr::null_mut()) as c_int
+}
+
+extern {
+    pub fn BIO_new(type_: *mut BIO_METHOD) -> *mut BIO;
+    pub fn BIO_s_file() -> *mut BIO_METHOD;
+    pub fn BIO_s_mem() -> *mut BIO_METHOD;
+
+    pub fn get_rfc2409_prime_768(bn: *mut BIGNUM) -> *mut BIGNUM;
+    pub fn get_rfc2409_prime_1024(bn: *mut BIGNUM) -> *mut BIGNUM;
+    pub fn get_rfc3526_prime_1536(bn: *mut BIGNUM) -> *mut BIGNUM;
+    pub fn get_rfc3526_prime_2048(bn: *mut BIGNUM) -> *mut BIGNUM;
+    pub fn get_rfc3526_prime_3072(bn: *mut BIGNUM) -> *mut BIGNUM;
+    pub fn get_rfc3526_prime_4096(bn: *mut BIGNUM) -> *mut BIGNUM;
+    pub fn get_rfc3526_prime_6144(bn: *mut BIGNUM) -> *mut BIGNUM;
+    pub fn get_rfc3526_prime_8192(bn: *mut BIGNUM) -> *mut BIGNUM;
+
+    pub fn CRYPTO_malloc(num: c_int, file: *const c_char, line: c_int) -> *mut c_void;
+    pub fn CRYPTO_free(buf: *mut c_void);
+    pub fn CRYPTO_num_locks() -> c_int;
+    pub fn CRYPTO_set_locking_callback(func: unsafe extern "C" fn(mode: c_int,
+                                                                  n: c_int,
+                                                                  file: *const c_char,
+                                                                  line: c_int));
+    pub fn CRYPTO_set_id_callback(func: unsafe extern "C" fn() -> c_ulong);
+
+    pub fn ERR_load_crypto_strings();
+
+    pub fn RSA_generate_key(modsz: c_int,
+                            e: c_ulong,
+                            cb: Option<extern fn(c_int, c_int, *mut c_void)>,
+                            cbarg: *mut c_void) -> *mut RSA;
+
+    pub fn OCSP_cert_to_id(dgst: *const ::EVP_MD, subject: *mut ::X509, issuer: *mut ::X509) -> *mut ::OCSP_CERTID;
+
+    pub fn PKCS12_create(pass: *mut c_char,
+                         friendly_name: *mut c_char,
+                         pkey: *mut EVP_PKEY,
+                         cert: *mut X509,
+                         ca: *mut stack_st_X509,
+                         nid_key: c_int,
+                         nid_cert: c_int,
+                         iter: c_int,
+                         mac_iter: c_int,
+                         keytype: c_int) -> *mut PKCS12;
+
+    pub fn SSL_library_init() -> c_int;
+    pub fn SSL_load_error_strings();
+    pub fn OPENSSL_add_all_algorithms_noconf();
+    pub fn HMAC_CTX_init(ctx: *mut ::HMAC_CTX);
+    pub fn HMAC_CTX_cleanup(ctx: *mut ::HMAC_CTX);
+    pub fn TLSv1_method() -> *const ::SSL_METHOD;
+    pub fn SSLv23_method() -> *const ::SSL_METHOD;
+    pub fn TLSv1_1_method() -> *const ::SSL_METHOD;
+    pub fn TLSv1_2_method() -> *const ::SSL_METHOD;
+    pub fn DTLSv1_method() -> *const ::SSL_METHOD;
+    pub fn SSL_get_ex_new_index(argl: c_long, argp: *mut c_void,
+                                new_func: Option<::CRYPTO_EX_new>,
+                                dup_func: Option<::CRYPTO_EX_dup>,
+                                free_func: Option<::CRYPTO_EX_free>)
+                                -> c_int;
+    pub fn SSL_set_tmp_ecdh_callback(ssl: *mut ::SSL,
+                                     ecdh: unsafe extern fn(ssl: *mut ::SSL,
+                                                            is_export: c_int,
+                                                            keylength: c_int)
+                                                            -> *mut ::EC_KEY);
+    pub fn SSL_CIPHER_get_version(cipher: *const ::SSL_CIPHER) -> *mut c_char;
+    pub fn SSL_CTX_get_ex_new_index(argl: c_long, argp: *mut c_void,
+                                    new_func: Option<::CRYPTO_EX_new>,
+                                    dup_func: Option<::CRYPTO_EX_dup>,
+                                    free_func: Option<::CRYPTO_EX_free>)
+                                    -> c_int;
+    pub fn SSL_CTX_set_tmp_ecdh_callback(ctx: *mut ::SSL_CTX,
+                                         ecdh: unsafe extern fn(ssl: *mut ::SSL,
+                                                                is_export: c_int,
+                                                                keylength: c_int)
+                                                                -> *mut ::EC_KEY);
+    pub fn X509_get_subject_name(x: *mut ::X509) -> *mut ::X509_NAME;
+    pub fn X509_set_notAfter(x: *mut ::X509, tm: *const ::ASN1_TIME) -> c_int;
+    pub fn X509_set_notBefore(x: *mut ::X509, tm: *const ::ASN1_TIME) -> c_int;
+    pub fn X509_get_ext_d2i(x: *mut ::X509, nid: c_int, crit: *mut c_int, idx: *mut c_int) -> *mut c_void;
+    pub fn X509_NAME_add_entry_by_NID(x: *mut ::X509_NAME, field: c_int, ty: c_int, bytes: *mut c_uchar, len: c_int, loc: c_int, set: c_int) -> c_int;
+    pub fn X509_NAME_get_entry(n: *mut ::X509_NAME, loc: c_int) -> *mut ::X509_NAME_ENTRY;
+    pub fn X509_NAME_ENTRY_get_data(ne: *mut ::X509_NAME_ENTRY) -> *mut ::ASN1_STRING;
+    pub fn X509_STORE_CTX_get_chain(ctx: *mut ::X509_STORE_CTX) -> *mut stack_st_X509;
+    pub fn X509V3_EXT_nconf_nid(conf: *mut ::CONF, ctx: *mut ::X509V3_CTX, ext_nid: c_int, value: *mut c_char) -> *mut ::X509_EXTENSION;
+    pub fn X509V3_EXT_nconf(conf: *mut ::CONF, ctx: *mut ::X509V3_CTX, name: *mut c_char, value: *mut c_char) -> *mut ::X509_EXTENSION;
+    pub fn ASN1_STRING_to_UTF8(out: *mut *mut c_uchar, s: *mut ::ASN1_STRING) -> c_int;
+    pub fn ASN1_STRING_data(x: *mut ::ASN1_STRING) -> *mut c_uchar;
+    pub fn CRYPTO_add_lock(pointer: *mut c_int,
+                           amount: c_int,
+                           type_: c_int,
+                           file: *const c_char,
+                           line: c_int) -> c_int;
+    pub fn EVP_MD_CTX_create() -> *mut EVP_MD_CTX;
+    pub fn EVP_MD_CTX_destroy(ctx: *mut EVP_MD_CTX);
+    pub fn EVP_PKEY_bits(key: *mut EVP_PKEY) -> c_int;
+
+    pub fn sk_new_null() -> *mut _STACK;
+    pub fn sk_num(st: *const _STACK) -> c_int;
+    pub fn sk_value(st: *const _STACK, n: c_int) -> *mut c_void;
+    pub fn sk_free(st: *mut _STACK);
+    pub fn sk_push(st: *mut _STACK, data: *mut c_void) -> c_int;
+    pub fn sk_pop_free(st: *mut _STACK, free: Option<unsafe extern "C" fn (*mut c_void)>);
+    pub fn sk_pop(st: *mut _STACK) -> *mut c_void;
+
+    pub fn SSLeay() -> c_ulong;
+    pub fn SSLeay_version(key: c_int) -> *const c_char;
+}