1 files changed, 63 insertions, 0 deletions
diff --git a/lib/crypto/c_src/chacha20.c b/lib/crypto/c_src/chacha20.c
new file mode 100644
index 0000000000..8c7df3c630
--- /dev/null
+++ b/lib/crypto/c_src/chacha20.c
@@ -0,0 +1,63 @@
+#include "chacha20.h"
+#include "cipher.h"
+
+ERL_NIF_TERM chacha20_stream_init(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+{/* (Key, IV) */
+#if defined(HAVE_CHACHA20)
+    ErlNifBinary     key_bin, ivec_bin;
+    struct evp_cipher_ctx *ctx;
+    const EVP_CIPHER *cipher;
+    ERL_NIF_TERM     ret;
+
+    if (!enif_inspect_iolist_as_binary(env, argv[0], &key_bin)
+        || !enif_inspect_binary(env, argv[1], &ivec_bin)
+        || key_bin.size != 32
+        || ivec_bin.size != 16) {
+        return enif_make_badarg(env);
+    }
+
+    cipher = EVP_chacha20();
+
+    ctx = enif_alloc_resource(evp_cipher_ctx_rtype, sizeof(struct evp_cipher_ctx));
+    ctx->ctx = EVP_CIPHER_CTX_new();
+
+
+    EVP_CipherInit_ex(ctx->ctx, cipher, NULL,
+                      key_bin.data, ivec_bin.data, 1);
+    EVP_CIPHER_CTX_set_padding(ctx->ctx, 0);
+    ret = enif_make_resource(env, ctx);
+    enif_release_resource(ctx);
+    return ret;
+#else
+    return enif_raise_exception(env, atom_notsup);
+#endif
+};
+
+ERL_NIF_TERM chacha20_stream_crypt(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+{/* (State, Data) */
+#if defined(HAVE_CHACHA20)
+    struct evp_cipher_ctx *ctx, *new_ctx;
+    ErlNifBinary   data_bin;
+    ERL_NIF_TERM   ret, cipher_term;
+    unsigned char  *out;
+    int            outl = 0;
+
+    if (!enif_get_resource(env, argv[0], evp_cipher_ctx_rtype, (void**)&ctx)
+        || !enif_inspect_iolist_as_binary(env, argv[1], &data_bin)) {
+        return enif_make_badarg(env);
+    }
+    new_ctx = enif_alloc_resource(evp_cipher_ctx_rtype, sizeof(struct evp_cipher_ctx));
+    new_ctx->ctx = EVP_CIPHER_CTX_new();
+    EVP_CIPHER_CTX_copy(new_ctx->ctx, ctx->ctx);
+    out = enif_make_new_binary(env, data_bin.size, &cipher_term);
+    EVP_CipherUpdate(new_ctx->ctx, out, &outl, data_bin.data, data_bin.size);
+    ASSERT(outl == data_bin.size);
+
+    ret = enif_make_tuple2(env, enif_make_resource(env, new_ctx), cipher_term);
+    enif_release_resource(new_ctx);
+    CONSUME_REDS(env,data_bin);
+    return ret;
+#else
+    return enif_raise_exception(env, atom_notsup);
+#endif
+};