1 files changed, 50 insertions, 0 deletions
diff --git a/src/basic/sha256.c b/src/basic/sha256.c
new file mode 100644
index 0000000..f011695
--- /dev/null
+++ b/src/basic/sha256.c
@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <unistd.h>
+
+#include "hexdecoct.h"
+#include "macro.h"
+#include "sha256.h"
+
+int sha256_fd(int fd, uint64_t max_size, uint8_t ret[static SHA256_DIGEST_SIZE]) {
+        struct sha256_ctx ctx;
+        uint64_t total_size = 0;
+
+        sha256_init_ctx(&ctx);
+
+        for (;;) {
+                uint8_t buffer[64 * 1024];
+                ssize_t n;
+
+                n = read(fd, buffer, sizeof(buffer));
+                if (n < 0)
+                        return -errno;
+                if (n == 0)
+                        break;
+
+                if (!INC_SAFE(&total_size, n) || total_size > max_size)
+                        return -EFBIG;
+
+                sha256_process_bytes(buffer, n, &ctx);
+        }
+
+        sha256_finish_ctx(&ctx, ret);
+        return 0;
+}
+
+int parse_sha256(const char *s, uint8_t ret[static SHA256_DIGEST_SIZE]) {
+        _cleanup_free_ uint8_t *data = NULL;
+        size_t size = 0;
+        int r;
+
+        if (!sha256_is_valid(s))
+                return -EINVAL;
+
+        r = unhexmem_full(s, SHA256_DIGEST_SIZE * 2, false, (void**) &data, &size);
+        if (r < 0)
+                return r;
+        assert(size == SHA256_DIGEST_SIZE);
+
+        memcpy(ret, data, size);
+        return 0;
+}