From: Alan T. DeKok <aland@freeradius.org>
Date: Tue, 13 Oct 2015 16:51:15 +0000 (-0400)
Subject: Port fix from v3.1.x
X-Git-Tag: release_3_0_11~254
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9f2f83128e64df51deb69839274550367039bb81;p=thirdparty%2Ffreeradius-server.git

Port fix from v3.1.x
---

diff --git a/src/main/tls.c b/src/main/tls.c
index bc9e233d6a7..2d0ff04d38c 100644
--- a/src/main/tls.c
+++ b/src/main/tls.c
@@ -1303,8 +1303,11 @@ static SSL_SESSION *cbtls_get_session(SSL *ssl, unsigned char *data, int len, in
 	{
 		int		rv, fd, todo;
 		char		filename[256];
-		unsigned char	*p;
-		unsigned char const *q;
+
+		unsigned char const	**o;
+		unsigned char		**p;
+		uint8_t			*q;
+
 		struct stat	st;
 		VALUE_PAIR	*vps = NULL;
 
@@ -1340,24 +1343,34 @@ static SSL_SESSION *cbtls_get_session(SSL *ssl, unsigned char *data, int len, in
 			goto err;
 		}
 
-		p = sess_data;
+		q = sess_data;
 		todo = st.st_size;
 		while (todo > 0) {
-			rv = read(fd, p, todo);
+			rv = read(fd, q, todo);
 			if (rv < 1) {
 				RWDEBUG("Failed reading persisted session: %s", fr_syserror(errno));
 				close(fd);
 				goto err;
 			}
 			todo -= rv;
-			p += rv;
+			q += rv;
 		}
 		close(fd);
 
-		/* openssl mutates &p */
+		/*
+		 *	OpenSSL mutates what's passed in, so we assign sess_data to q,
+		 *	so the value of q gets mutated, and not the value of sess_data.
+		 *
+		 *	We then need a pointer to hold &q, but it can't be const, because
+		 *	clang complains about lack of consting in nested pointer types.
+		 *
+		 *	So we memcpy the value of that pointer, to one that
+		 *	does have a const, which we then pass into d2i_SSL_SESSION *sigh*.
+		 */
 		q = sess_data;
-		sess = d2i_SSL_SESSION(NULL, &q, st.st_size);
-
+		p = &q;
+		memcpy(&o, &p, sizeof(o));
+		sess = d2i_SSL_SESSION(NULL, o, st.st_size);
 		if (!sess) {
 			RWDEBUG("Failed loading persisted session: %s", ERR_error_string(ERR_get_error(), NULL));
 			goto err;