v2.2.2

vendor/zuptsdk/include/zsdk_xchacha20_poly1305.h

@@ -0,0 +1,57 @@
+/*
+ * XChaCha20-Poly1305 AEAD
+ * Copyright (c) 2026 Cristian Cezar Moisés
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ *
+ * Implements:
+ *   - ChaCha20 (RFC 8439)
+ *   - HChaCha20 (draft-irtf-cfrg-xchacha-03 §2.2)
+ *   - XChaCha20 (draft-irtf-cfrg-xchacha-03 §2.3)
+ *   - Poly1305 (RFC 8439 §2.5)
+ *   - XChaCha20-Poly1305 AEAD (draft-irtf-cfrg-xchacha-03 §2.4)
+ *
+ * Constant-time implementation: no secret-dependent branches or memory
+ * accesses. Verified against RFC 8439 test vectors and Wycheproof corpus.
+ */
+
+#ifndef ZUPTSDK_XCHACHA20_POLY1305_H
+#define ZUPTSDK_XCHACHA20_POLY1305_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define ZSDK_XCHACHA20_POLY1305_KEYBYTES   32
+#define ZSDK_XCHACHA20_POLY1305_NONCEBYTES 24
+#define ZSDK_XCHACHA20_POLY1305_TAGBYTES   16
+
+/* Encrypt: ciphertext_len = plaintext_len; tag is 16 bytes appended.
+ * out buffer size must be >= plaintext_len + 16. */
+void zsdk_xchacha20_poly1305_encrypt(
+    uint8_t       *out,        /* [out] ciphertext || tag */
+    const uint8_t *plaintext,
+    size_t         plaintext_len,
+    const uint8_t *aad,
+    size_t         aad_len,
+    const uint8_t  key[32],
+    const uint8_t  nonce[24]);
+
+/* Decrypt: returns 0 on success, -1 on tag mismatch (out untouched).
+ * out buffer size must be >= ciphertext_len - 16. */
+int zsdk_xchacha20_poly1305_decrypt(
+    uint8_t       *out,        /* [out] plaintext */
+    const uint8_t *ciphertext, /* ciphertext || tag */
+    size_t         ciphertext_len, /* includes 16-byte tag */
+    const uint8_t *aad,
+    size_t         aad_len,
+    const uint8_t  key[32],
+    const uint8_t  nonce[24]);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif