add encrypting for save files

add libhydrogen for encrypting and decrypting #9
2026-04-03 14:59:37 +02:00
parent abb6556fd4
commit c277ab10d9
68 changed files with 5737 additions and 74 deletions
@@ -0,0 +1,85 @@
+#include <errno.h>
+#include <fcntl.h>
+#ifdef __linux__
+#    include <poll.h>
+#endif
+#include <sys/types.h>
+#include <unistd.h>
+
+#ifdef __linux__
+static int
+hydro_random_block_on_dev_random(void)
+{
+    struct pollfd pfd;
+    int           fd;
+    int           pret;
+
+    fd = open("/dev/random", O_RDONLY);
+    if (fd == -1) {
+        return 0;
+    }
+    pfd.fd      = fd;
+    pfd.events  = POLLIN;
+    pfd.revents = 0;
+    do {
+        pret = poll(&pfd, 1, -1);
+    } while (pret < 0 && (errno == EINTR || errno == EAGAIN));
+    if (pret != 1) {
+        (void) close(fd);
+        errno = EIO;
+        return -1;
+    }
+    return close(fd);
+}
+#endif
+
+static ssize_t
+hydro_random_safe_read(const int fd, void *const buf_, size_t len)
+{
+    unsigned char *buf = (unsigned char *) buf_;
+    ssize_t        readnb;
+
+    do {
+        while ((readnb = read(fd, buf, len)) < (ssize_t) 0 && (errno == EINTR || errno == EAGAIN)) {
+        }
+        if (readnb < (ssize_t) 0) {
+            return readnb;
+        }
+        if (readnb == (ssize_t) 0) {
+            break;
+        }
+        len -= (size_t) readnb;
+        buf += readnb;
+    } while (len > (ssize_t) 0);
+
+    return (ssize_t) (buf - (unsigned char *) buf_);
+}
+
+static int
+hydro_random_init(void)
+{
+    uint8_t tmp[gimli_BLOCKBYTES + 8];
+    int     fd;
+    int     ret = -1;
+
+#ifdef __linux__
+    if (hydro_random_block_on_dev_random() != 0) {
+        return -1;
+    }
+#endif
+    do {
+        fd = open("/dev/urandom", O_RDONLY);
+        if (fd == -1 && errno != EINTR) {
+            return -1;
+        }
+    } while (fd == -1);
+    if (hydro_random_safe_read(fd, tmp, sizeof tmp) == (ssize_t) sizeof tmp) {
+        memcpy(hydro_random_context.state, tmp, gimli_BLOCKBYTES);
+        memcpy(&hydro_random_context.counter, tmp + gimli_BLOCKBYTES, 8);
+        hydro_memzero(tmp, sizeof tmp);
+        ret = 0;
+    }
+    ret |= close(fd);
+
+    return ret;
+}