1 files changed, 21 insertions, 7 deletions

diff --git a/lib/utils_crypt.c b/lib/utils_crypt.c
index 9fc05ac..5cfe477 100644
--- a/lib/utils_crypt.c
+++ b/lib/utils_crypt.c
@@ -81,6 +81,18 @@ int crypt_parse_name_and_mode(const char *s, char *cipher, int *key_nums,
 	return -EINVAL;
 }
 
+/*
+ * Replacement for memset(s, 0, n) on stack that can be optimized out
+ * Also used in safe allocations for explicit memory wipe.
+ */
+void crypt_memzero(void *s, size_t n)
+{
+	volatile uint8_t *p = (volatile uint8_t *)s;
+
+	while(n--)
+		*p++ = 0;
+}
+
 /* safe allocations */
 void *crypt_safe_alloc(size_t size)
 {
@@ -94,7 +106,7 @@ void *crypt_safe_alloc(size_t size)
 		return NULL;
 
 	alloc->size = size;
-	memset(&alloc->data, 0, size);
+	crypt_memzero(&alloc->data, size);
 
 	/* coverity[leaked_storage] */
 	return &alloc->data;
@@ -110,7 +122,7 @@ void crypt_safe_free(void *data)
 	alloc = (struct safe_allocation *)
 		((char *)data - offsetof(struct safe_allocation, data));
 
-	memset(data, 0, alloc->size);
+	crypt_memzero(data, alloc->size);
 
 	alloc->size = 0x55aa55aa;
 	free(alloc);
@@ -157,7 +169,7 @@ static int untimed_read(int fd, char *pass, size_t maxlen)
 static int timed_read(int fd, char *pass, size_t maxlen, long timeout)
 {
 	struct timeval t;
-	fd_set fds;
+	fd_set fds = {}; /* Just to avoid scan-build false report for FD_SET */
 	int failed = -1;
 
 	FD_ZERO(&fds);
@@ -176,16 +188,18 @@ static int interactive_pass(const char *prompt, char *pass, size_t maxlen,
 {
 	struct termios orig, tmp;
 	int failed = -1;
-	int infd = STDIN_FILENO, outfd;
+	int infd, outfd;
 
 	if (maxlen < 1)
-		goto out_err;
+		return failed;
 
 	/* Read and write to /dev/tty if available */
-	if ((infd = outfd = open("/dev/tty", O_RDWR)) == -1) {
+	infd = open("/dev/tty", O_RDWR);
+	if (infd == -1) {
 		infd = STDIN_FILENO;
 		outfd = STDERR_FILENO;
-	}
+	} else
+		outfd = infd;
 
 	if (tcgetattr(infd, &orig))
 		goto out_err;