added devcontainer

src/crypto.h

@@ -0,0 +1,45 @@
+#ifndef OPENUF_CRYPTO_H
+#define OPENUF_CRYPTO_H
+
+#include <stddef.h>
+
+/*
+ * AES-128-CBC helpers using mbedTLS.
+ *
+ * All keys and IVs are passed as 32-char hex strings (16 bytes).
+ * All in/out buffers are raw binary.
+ */
+
+/* Generate random bytes, return as hex string.
+ * hex_out must be at least nbytes*2+1 bytes. */
+int  crypto_random_hex(unsigned char *hex_out, int nbytes);
+
+/* AES-128-CBC encrypt.
+ * out must be >= in_len + 16 (PKCS#7 padded to block boundary).
+ * Returns ciphertext length, or -1 on error. */
+int  crypto_encrypt(const char *key_hex, const char *iv_hex,
+                    const unsigned char *in, size_t in_len,
+                    unsigned char *out);
+
+/* AES-128-CBC decrypt.
+ * out must be >= in_len bytes.
+ * Returns plaintext length (PKCS#7 unpadded), or -1 on error. */
+int  crypto_decrypt(const char *key_hex, const char *iv_hex,
+                    const unsigned char *in, size_t in_len,
+                    unsigned char *out);
+
+/* AES-128-GCM with a 16-byte authentication tag. */
+int crypto_gcm_encrypt(const char *key_hex, const char *iv_hex,
+                       const unsigned char *aad, size_t aad_len,
+                       const unsigned char *in, size_t in_len,
+                       unsigned char *out, unsigned char tag[16]);
+int crypto_gcm_decrypt(const char *key_hex, const char *iv_hex,
+                       const unsigned char *aad, size_t aad_len,
+                       const unsigned char *in, size_t in_len,
+                       const unsigned char tag[16], unsigned char *out);
+
+/* Hex <-> binary conversions */
+void crypto_hex2bin(const char *hex, unsigned char *bin, size_t bin_len);
+void crypto_bin2hex(const unsigned char *bin, size_t bin_len, char *hex_out);
+
+#endif /* OPENUF_CRYPTO_H */