Wipe (some) secrets from memory after use

[tinc] / src / ed25519 / ecdsa.c

diff --git a/src/ed25519/ecdsa.c b/src/ed25519/ecdsa.c
index f0ce2c1..28daf4a 100644 (file)
--- a/src/ed25519/ecdsa.c
+++ b/src/ed25519/ecdsa.c
@@ -47,7 +47,7 @@ ecdsa_t *ecdsa_set_base64_public_key(const char *p) {
 
        if(len != 32) {
                logger(DEBUG_ALWAYS, LOG_ERR, "Invalid format of public key! len = %lu", (unsigned long)len);
-               free(ecdsa);
+               ecdsa_free(ecdsa);
                return 0;
        }
 
@@ -64,6 +64,7 @@ char *ecdsa_get_base64_public_key(ecdsa_t *ecdsa) {
 // Read PEM ECDSA keys
 
 static bool read_pem(FILE *fp, const char *type, void *vbuf, size_t size) {
+       const size_t buflen = size;
        char line[1024];
        bool data = false;
        size_t typelen = strlen(type);
@@ -90,16 +91,10 @@ static bool read_pem(FILE *fp, const char *type, void *vbuf, size_t size) {
                size_t linelen = strcspn(line, "\r\n");
                size_t len = b64decode_tinc(line, line, linelen);
 
-               if(!len) {
-                       logger(DEBUG_ALWAYS, LOG_ERR, "Invalid base64 data in PEM file\n");
+               if(!len || len > size) {
+                       logger(DEBUG_ALWAYS, LOG_ERR, "%s base64 data in PEM file\n", len ? "Too much" : "Invalid");
                        errno = EINVAL;
-                       return false;
-               }
-
-               if(len > size) {
-                       logger(DEBUG_ALWAYS, LOG_ERR, "Too much base64 data in PEM file\n");
-                       errno = EINVAL;
-                       return false;
+                       goto exit;
                }
 
                memcpy(buf, line, len);
@@ -114,7 +109,13 @@ static bool read_pem(FILE *fp, const char *type, void *vbuf, size_t size) {
                } else {
                        errno = ENOENT;
                }
+       }
+
+exit:
+       memzero(line, sizeof(line));
 
+       if(size) {
+               memzero(vbuf, buflen);
                return false;
        }
 
@@ -128,8 +129,8 @@ ecdsa_t *ecdsa_read_pem_public_key(FILE *fp) {
                return ecdsa;
        }
 
-       free(ecdsa);
-       return 0;
+       ecdsa_free(ecdsa);
+       return NULL;
 }
 
 ecdsa_t *ecdsa_read_pem_private_key(FILE *fp) {
@@ -139,8 +140,8 @@ ecdsa_t *ecdsa_read_pem_private_key(FILE *fp) {
                return ecdsa;
        }
 
-       free(ecdsa);
-       return 0;
+       ecdsa_free(ecdsa);
+       return NULL;
 }
 
 size_t ecdsa_size(ecdsa_t *ecdsa) {
@@ -164,5 +165,5 @@ bool ecdsa_active(ecdsa_t *ecdsa) {
 }
 
 void ecdsa_free(ecdsa_t *ecdsa) {
-       free(ecdsa);
+       xzfree(ecdsa, sizeof(ecdsa_t));
 }