Merge pull request #2421 from libgit2/cmn/init-ssl-once

netops: init OpenSSL once under lock

src/global.c

@@ -16,6 +16,12 @@ git_mutex git__mwindow_mutex;
 
 #define MAX_SHUTDOWN_CB 8
 
+#ifdef GIT_SSL
+# include <openssl/ssl.h>
+SSL_CTX *git__ssl_ctx;
+static git_mutex *openssl_locks;
+#endif
+
 static git_global_shutdown_fn git__shutdown_callbacks[MAX_SHUTDOWN_CB];
 static git_atomic git__n_shutdown_callbacks;
 static git_atomic git__n_inits;
@@ -39,6 +45,62 @@ static void git__shutdown(void)
 
 }
 
+#if defined(GIT_THREADS) && defined(GIT_SSL)
+void openssl_locking_function(int mode, int n, const char *file, int line)
+{
+	int lock;
+
+	GIT_UNUSED(file);
+	GIT_UNUSED(line);
+
+	lock = mode & CRYPTO_LOCK;
+
+	if (lock) {
+		git_mutex_lock(&openssl_locks[n]);
+	} else {
+		git_mutex_unlock(&openssl_locks[n]);
+	}
+}
+#endif
+
+
+static void init_ssl(void)
+{
+#ifdef GIT_SSL
+	SSL_load_error_strings();
+	OpenSSL_add_ssl_algorithms();
+	git__ssl_ctx = SSL_CTX_new(SSLv23_method());
+	SSL_CTX_set_mode(git__ssl_ctx, SSL_MODE_AUTO_RETRY);
+	SSL_CTX_set_verify(git__ssl_ctx, SSL_VERIFY_NONE, NULL);
+	if (!SSL_CTX_set_default_verify_paths(git__ssl_ctx)) {
+		SSL_CTX_free(git__ssl_ctx);
+		git__ssl_ctx = NULL;
+	}
+
+# ifdef GIT_THREADS
+	{
+		int num_locks, i;
+
+		num_locks = CRYPTO_num_locks();
+		openssl_locks = git__calloc(num_locks, sizeof(git_mutex));
+		if (openssl_locks == NULL) {
+			SSL_CTX_free(git__ssl_ctx);
+			git__ssl_ctx = NULL;
+		}
+
+		for (i = 0; i < num_locks; i++) {
+			if (git_mutex_init(&openssl_locks[i]) != 0) {
+				SSL_CTX_free(git__ssl_ctx);
+				git__ssl_ctx = NULL;
+			}
+		}
+
+		CRYPTO_set_locking_callback(openssl_locking_function);
+	}
+# endif
+#endif
+}
+
 /**
  * Handle the global state with TLS
  *
@@ -168,10 +230,14 @@ static void init_once(void)
 		return;
 	pthread_key_create(&_tls_key, &cb__free_status);
 
+
 	/* Initialize any other subsystems that have global state */
 	if ((init_error = git_hash_global_init()) >= 0)
 		init_error = git_sysdir_global_init();
 
+	/* OpenSSL needs to be initialized from the main thread */
+	init_ssl();
+
 	GIT_MEMORY_BARRIER;
 }
 
@@ -225,6 +291,7 @@ static git_global_st __state;
 
 int git_threads_init(void)
 {
+	init_ssl();
 	git_atomic_inc(&git__n_inits);
 	return 0;
 }

src/global.h

@@ -15,6 +15,11 @@ typedef struct {
 	git_error error_t;
 } git_global_st;
 
+#ifdef GIT_SSL
+# include <openssl/ssl.h>
+extern SSL_CTX *git__ssl_ctx;
+#endif
+
 git_global_st *git__global_state(void);
 
 extern git_mutex git__mwindow_mutex;

src/netops.c

@@ -33,6 +33,7 @@
 #include "posix.h"
 #include "buffer.h"
 #include "http_parser.h"
+#include "global.h"
 
 #ifdef GIT_WIN32
 static void net_set_error(const char *str)
@@ -157,7 +158,7 @@ void gitno_buffer_setup_callback(
 void gitno_buffer_setup(gitno_socket *socket, gitno_buffer *buf, char *data, size_t len)
 {
 #ifdef GIT_SSL
-	if (socket->ssl.ctx) {
+	if (socket->ssl.ssl) {
 		gitno_buffer_setup_callback(socket, buf, data, len, gitno__recv_ssl, NULL);
 		return;
 	}
@@ -202,7 +203,6 @@ static int gitno_ssl_teardown(gitno_ssl *ssl)
 		ret = 0;
 
 	SSL_free(ssl->ssl);
-	SSL_CTX_free(ssl->ctx);
 	return ret;
 }
 
@@ -390,18 +390,12 @@ static int ssl_setup(gitno_socket *socket, const char *host, int flags)
 {
 	int ret;
 
-	SSL_library_init();
-	SSL_load_error_strings();
-	socket->ssl.ctx = SSL_CTX_new(SSLv23_method());
-	if (socket->ssl.ctx == NULL)
-		return ssl_set_error(&socket->ssl, 0);
+	if (git__ssl_ctx == NULL) {
+		giterr_set(GITERR_NET, "OpenSSL initialization failed");
+		return -1;
+	}
 
-	SSL_CTX_set_mode(socket->ssl.ctx, SSL_MODE_AUTO_RETRY);
-	SSL_CTX_set_verify(socket->ssl.ctx, SSL_VERIFY_NONE, NULL);
-	if (!SSL_CTX_set_default_verify_paths(socket->ssl.ctx))
-		return ssl_set_error(&socket->ssl, 0);
-
-	socket->ssl.ssl = SSL_new(socket->ssl.ctx);
+	socket->ssl.ssl = SSL_new(git__ssl_ctx);
 	if (socket->ssl.ssl == NULL)
 		return ssl_set_error(&socket->ssl, 0);
 
@@ -538,7 +532,7 @@ int gitno_send(gitno_socket *socket, const char *msg, size_t len, int flags)
 	size_t off = 0;
 
 #ifdef GIT_SSL
-	if (socket->ssl.ctx)
+	if (socket->ssl.ssl)
 		return gitno_send_ssl(&socket->ssl, msg, len, flags);
 #endif
 
@@ -559,7 +553,7 @@ int gitno_send(gitno_socket *socket, const char *msg, size_t len, int flags)
 int gitno_close(gitno_socket *s)
 {
 #ifdef GIT_SSL
-	if (s->ssl.ctx &&
+	if (s->ssl.ssl &&
 		gitno_ssl_teardown(&s->ssl) < 0)
 		return -1;
 #endif

src/netops.h

@@ -16,7 +16,6 @@
 
 struct gitno_ssl {
 #ifdef GIT_SSL
-	SSL_CTX *ctx;
 	SSL *ssl;
 #else
 	size_t dummy;