Remove logging of sensitive information

I prefer to have these independent of the crypto suite that's being used.

include/base64.h

@@ -0,0 +1,25 @@
+/* Copyright (c) 2023 Andri Yngvason
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#pragma once
+
+#include <stdint.h>
+#include <unistd.h>
+
+#define BASE64_ENCODED_SIZE(x) ((((x) + 2) / 3) * 4 + 1)
+#define BASE64_DECODED_MAX_SIZE(x) ((((x) + 3) / 4) * 3)
+
+void base64_encode(char* dst, const uint8_t* src, size_t src_len);
+ssize_t base64_decode(uint8_t* dst, const char* src);

include/common.h

@@ -26,6 +26,10 @@
 #include "neatvnc.h"
 #include "config.h"
 
+#ifdef HAVE_CRYPTO
+#include "crypto.h"
+#endif
+
 #ifdef ENABLE_TLS
 #include <gnutls/gnutls.h>
 #endif
@@ -43,6 +47,13 @@ enum nvnc_client_state {
 	VNC_CLIENT_STATE_WAITING_FOR_VENCRYPT_VERSION,
 	VNC_CLIENT_STATE_WAITING_FOR_VENCRYPT_SUBTYPE,
 	VNC_CLIENT_STATE_WAITING_FOR_VENCRYPT_PLAIN_AUTH,
+#endif
+#ifdef HAVE_CRYPTO
+	VNC_CLIENT_STATE_WAITING_FOR_APPLE_DH_RESPONSE,
+	VNC_CLIENT_STATE_WAITING_FOR_RSA_AES_PUBLIC_KEY,
+	VNC_CLIENT_STATE_WAITING_FOR_RSA_AES_CHALLENGE,
+	VNC_CLIENT_STATE_WAITING_FOR_RSA_AES_CLIENT_HASH,
+	VNC_CLIENT_STATE_WAITING_FOR_RSA_AES_CREDENTIALS,
 #endif
 	VNC_CLIENT_STATE_WAITING_FOR_INIT,
 	VNC_CLIENT_STATE_READY,
@@ -53,6 +64,9 @@ struct stream;
 struct aml_handler;
 struct aml_idle;
 struct nvnc_display;
+struct crypto_key;
+struct crypto_rsa_pub_key;
+struct crypto_rsa_priv_key;
 
 struct nvnc_common {
 	void* userdata;
@@ -93,6 +107,18 @@ struct nvnc_client {
 	struct encoder* encoder;
 	uint32_t cursor_seq;
 	int quality;
+
+#ifdef HAVE_CRYPTO
+	struct crypto_key* apple_dh_secret;
+
+	struct {
+		enum crypto_hash_type hash_type;
+		enum crypto_cipher_type cipher_type;
+		size_t challenge_len;
+		uint8_t challenge[32];
+		struct crypto_rsa_pub_key* pub;
+	} rsa;
+#endif
 };
 
 LIST_HEAD(nvnc_client_list, nvnc_client);
@@ -132,6 +158,11 @@ struct nvnc {
 	void* auth_ud;
 #endif
 
+#ifdef HAVE_CRYPTO
+	struct crypto_rsa_pub_key* rsa_pub;
+	struct crypto_rsa_priv_key* rsa_priv;
+#endif
+
 	uint32_t n_damage_clients;
 };
 

include/crypto.h

@@ -0,0 +1,113 @@
+#pragma once
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <unistd.h>
+
+struct crypto_key;
+struct crypto_cipher;
+struct crypto_hash;
+struct crypto_rsa_pub_key;
+struct crypto_rsa_priv_key;
+struct vec;
+
+enum crypto_cipher_type {
+	CRYPTO_CIPHER_INVALID = 0,
+	CRYPTO_CIPHER_AES128_ECB,
+	CRYPTO_CIPHER_AES_EAX,
+	CRYPTO_CIPHER_AES256_EAX,
+};
+
+enum crypto_hash_type {
+	CRYPTO_HASH_INVALID = 0,
+	CRYPTO_HASH_MD5,
+	CRYPTO_HASH_SHA1,
+	CRYPTO_HASH_SHA256,
+};
+
+struct crypto_data_entry {
+	uint8_t* data;
+	size_t len;
+};
+
+void crypto_dump_base16(const char* msg, const uint8_t* bytes, size_t len);
+void crypto_dump_base64(const char* msg, const uint8_t* bytes, size_t len);
+
+void crypto_random(uint8_t* dst, size_t len);
+
+// Key generation
+struct crypto_key* crypto_key_new(int g, const uint8_t *p, uint32_t p_len,
+		const uint8_t* q, uint32_t q_len);
+void crypto_key_del(struct crypto_key* key);
+
+int crypto_key_g(const struct crypto_key* key);
+uint32_t crypto_key_p(const struct crypto_key* key, uint8_t* dst,
+		uint32_t dst_size);
+uint32_t crypto_key_q(const struct crypto_key* key, uint8_t* dst,
+		uint32_t dst_size);
+
+struct crypto_key* crypto_keygen(void);
+
+// Diffie-Hellman
+struct crypto_key* crypto_derive_public_key(const struct crypto_key* priv);
+struct crypto_key* crypto_derive_shared_secret(
+		const struct crypto_key* own_secret,
+		const struct crypto_key* remote_public_key);
+
+// Ciphers
+struct crypto_cipher* crypto_cipher_new(const uint8_t* enc_key,
+		const uint8_t* dec_key, enum crypto_cipher_type type);
+void crypto_cipher_del(struct crypto_cipher* self);
+
+bool crypto_cipher_encrypt(struct crypto_cipher* self, struct vec* dst,
+		uint8_t* mac, const uint8_t* src, size_t len,
+		const uint8_t* ad, size_t ad_len);
+ssize_t crypto_cipher_decrypt(struct crypto_cipher* self, uint8_t* dst,
+		uint8_t* mac, const uint8_t* src, size_t len,
+		const uint8_t* ad, size_t ad_len);
+
+// Hashing
+struct crypto_hash* crypto_hash_new(enum crypto_hash_type type);
+void crypto_hash_del(struct crypto_hash* self);
+
+void crypto_hash_append(struct crypto_hash* self, const uint8_t* src,
+		size_t len);
+void crypto_hash_digest(struct crypto_hash* self, uint8_t* dst,
+		size_t len);
+
+void crypto_hash_one(uint8_t* dst, size_t dst_len, enum crypto_hash_type type,
+		const uint8_t* src, size_t src_len);
+void crypto_hash_many(uint8_t* dst, size_t dst_len, enum crypto_hash_type type,
+		const struct crypto_data_entry *src);
+
+// RSA
+struct crypto_rsa_pub_key* crypto_rsa_pub_key_new(void);
+void crypto_rsa_pub_key_del(struct crypto_rsa_pub_key*);
+
+// Returns length in bytes
+size_t crypto_rsa_pub_key_length(const struct crypto_rsa_pub_key* key);
+
+struct crypto_rsa_pub_key* crypto_rsa_pub_key_import(const uint8_t* modulus,
+		const uint8_t* exponent, size_t size);
+
+void crypto_rsa_pub_key_modulus(const struct crypto_rsa_pub_key* key,
+		uint8_t* dst, size_t dst_size);
+void crypto_rsa_pub_key_exponent(const struct crypto_rsa_pub_key* key,
+		uint8_t* dst, size_t dst_size);
+
+bool crypto_rsa_priv_key_import_pkcs1_der(struct crypto_rsa_priv_key* priv,
+		struct crypto_rsa_pub_key* pub, const uint8_t* key,
+		size_t size);
+
+bool crypto_rsa_priv_key_load(struct crypto_rsa_priv_key* priv,
+		struct crypto_rsa_pub_key* pub, const char* path);
+
+struct crypto_rsa_priv_key *crypto_rsa_priv_key_new(void);
+void crypto_rsa_priv_key_del(struct crypto_rsa_priv_key*);
+
+bool crypto_rsa_keygen(struct crypto_rsa_pub_key*, struct crypto_rsa_priv_key*);
+
+ssize_t crypto_rsa_encrypt(struct crypto_rsa_pub_key* pub, uint8_t* dst,
+		size_t dst_size, const uint8_t* src, size_t src_size);
+ssize_t crypto_rsa_decrypt(struct crypto_rsa_priv_key* priv, uint8_t* dst,
+		size_t dst_size, const uint8_t* src, size_t src_size);

include/neatvnc.h

@@ -48,6 +48,9 @@
 #define nvnc_trace(...)
 #endif
 
+#define NVNC_BASE64_ENCODED_SIZE(x) ((((x) + 2) / 3) * 4 + 1)
+#define NVNC_BASE64_DECODED_MAX_SIZE(x) ((((x) + 3) / 4) * 3)
+
 struct nvnc;
 struct nvnc_client;
 struct nvnc_desktop_layout;
@@ -154,10 +157,19 @@ void nvnc_set_client_cleanup_fn(struct nvnc_client* self, nvnc_client_fn fn);
 void nvnc_set_cut_text_fn(struct nvnc*, nvnc_cut_text_fn fn);
 void nvnc_set_desktop_layout_fn(struct nvnc* self, nvnc_desktop_layout_fn);
 
+/* TODO: Changes this interface so that we have enable_auth(auth_fn),
+ * set_tls_creds(key, cert), and has_tls() -> bool
+ */
+
 bool nvnc_has_auth(void);
+
 int nvnc_enable_auth(struct nvnc* self, const char* privkey_path,
                      const char* cert_path, nvnc_auth_fn, void* userdata);
 
+int nvnc_enable_auth2(struct nvnc* self, nvnc_auth_fn, void* userdata);
+
+int nvnc_set_rsa_creds(struct nvnc* self, const char* private_key_path);
+
 struct nvnc_fb* nvnc_fb_new(uint16_t width, uint16_t height,
                             uint32_t fourcc_format, uint16_t stride);
 struct nvnc_fb* nvnc_fb_from_buffer(void* buffer, uint16_t width,
@@ -230,3 +242,6 @@ void nvnc_set_cursor(struct nvnc*, struct nvnc_fb*, uint16_t width,
 void nvnc_set_log_fn(nvnc_log_fn);
 void nvnc_set_log_level(enum nvnc_log_level);
 void nvnc__log(const struct nvnc_log_data*, const char* fmt, ...);
+
+void nvnc_base64_encode(char* dst, const uint8_t* src, size_t src_len);
+ssize_t nvnc_base64_decode(uint8_t* dst, const char* src);

include/rfb-proto.h

@@ -29,8 +29,11 @@ enum rfb_security_type {
 	RFB_SECURITY_TYPE_INVALID = 0,
 	RFB_SECURITY_TYPE_NONE = 1,
 	RFB_SECURITY_TYPE_VNC_AUTH = 2,
+	RFB_SECURITY_TYPE_RSA_AES = 5,
 	RFB_SECURITY_TYPE_TIGHT = 16,
 	RFB_SECURITY_TYPE_VENCRYPT = 19,
+	RFB_SECURITY_TYPE_APPLE_DH = 30,
+	RFB_SECURITY_TYPE_RSA_AES256 = 129,
 };
 
 enum rfb_security_handshake_result {
@@ -106,9 +109,14 @@ enum rfb_resize_status {
 	RFB_RESIZE_STATUS_REQUEST_FORWARDED = 4,
 };
 
+enum rfb_rsa_aes_cred_subtype {
+	RFB_RSA_AES_CRED_SUBTYPE_USER_AND_PASS = 1,
+	RFB_RSA_AES_CRED_SUBTYPE_ONLY_PASS = 2,
+};
+
 struct rfb_security_types_msg {
 	uint8_t n;
-	uint8_t types[1];
+	uint8_t types[0];
 } RFB_PACKED;
 
 struct rfb_error_reason {
@@ -237,3 +245,24 @@ struct rfb_ntp_msg {
 	uint8_t padding[3];
 	uint32_t t0, t1, t2, t3;
 } RFB_PACKED;
+
+struct rfb_apple_dh_server_msg {
+	uint16_t generator;
+	uint16_t key_size;
+	uint8_t modulus_and_key[0];
+} RFB_PACKED;
+
+struct rfb_apple_dh_client_msg {
+	uint8_t encrypted_credentials[128];
+	uint8_t public_key[0];
+} RFB_PACKED;
+
+struct rfb_rsa_aes_pub_key_msg {
+	uint32_t length;
+	uint8_t modulus_and_exponent[0];
+} RFB_PACKED;
+
+struct rfb_rsa_aes_challenge_msg {
+	uint16_t length;
+	uint8_t challenge[0];
+} RFB_PACKED;

include/stream-tcp.h

@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2023 Andri Yngvason
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#pragma once
+
+#include "stream.h"
+
+#include <unistd.h>
+
+struct stream;
+
+int stream_tcp_init(struct stream* self, int fd, stream_event_fn on_event,
+		void* userdata);
+int stream_tcp_close(struct stream* self);
+void stream_tcp_destroy(struct stream* self);
+ssize_t stream_tcp_read(struct stream* self, void* dst, size_t size);
+int stream_tcp_send(struct stream* self, struct rcbuf* payload,
+                stream_req_fn on_done, void* userdata);
+int stream_tcp_send_first(struct stream* self, struct rcbuf* payload);
+void stream_tcp_exec_and_send(struct stream* self,
+		stream_exec_fn exec_fn, void* userdata);
+int stream_tcp_install_cipher(struct stream* self,
+		struct crypto_cipher* cipher);

include/stream.h

@@ -19,6 +19,11 @@
 #include "config.h"
 #include "sys/queue.h"
 #include "rcbuf.h"
+#include "vec.h"
+
+#ifdef HAVE_CRYPTO
+#include "crypto.h"
+#endif
 
 #include <stdint.h>
 #include <stdbool.h>
@@ -45,6 +50,7 @@ enum stream_event {
 };
 
 struct stream;
+struct crypto_cipher;
 
 typedef void (*stream_event_fn)(struct stream*, enum stream_event);
 typedef void (*stream_req_fn)(void*, enum stream_req_status);
@@ -86,6 +92,9 @@ struct stream {
 	uint32_t bytes_received;
 
 	bool cork;
+
+	struct crypto_cipher* cipher;
+	struct vec tmp_buf;
 };
 
 #ifdef ENABLE_WEBSOCKET
@@ -108,3 +117,9 @@ void stream_exec_and_send(struct stream* self, stream_exec_fn, void* userdata);
 #ifdef ENABLE_TLS
 int stream_upgrade_to_tls(struct stream* self, void* context);
 #endif
+
+#ifdef HAVE_CRYPTO
+int stream_upgrade_to_rsa_eas(struct stream* base,
+		enum crypto_cipher_type cipher_type,
+		const uint8_t* enc_key, const uint8_t* dec_key);
+#endif

meson.build

@@ -51,6 +51,8 @@ pixman = dependency('pixman-1')
 libturbojpeg = dependency('libturbojpeg', required: get_option('jpeg'))
 gnutls = dependency('gnutls', required: get_option('tls'))
 nettle = dependency('nettle', required: get_option('nettle'))
+hogweed = dependency('hogweed', required: get_option('nettle'))
+gmp = dependency('gmp', required: get_option('nettle'))
 zlib = dependency('zlib')
 gbm = dependency('gbm', required: get_option('gbm'))
 libdrm = dependency('libdrm', required: get_option('h264'))
@@ -93,6 +95,7 @@ sources = [
 	'src/encoder.c',
 	'src/cursor.c',
 	'src/logging.c',
+	'src/base64.c',
 ]
 
 dependencies = [
@@ -118,9 +121,11 @@ if gnutls.found()
 	config.set('ENABLE_TLS', true)
 endif
 
-if nettle.found()
+if nettle.found() and hogweed.found() and gmp.found()
-	dependencies += nettle
+	dependencies += [ nettle, hogweed, gmp ]
 	enable_websocket = true
+	config.set('HAVE_CRYPTO', true)
+	sources += ['src/crypto-nettle.c', 'src/stream-rsa-aes.c']
 endif
 
 if host_system == 'linux' and get_option('systemtap') and cc.has_header('sys/sdt.h')

src/base64.c

@@ -0,0 +1,170 @@
+/* Copyright (c) 2023 Andri Yngvason
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "base64.h"
+#include "neatvnc.h"
+
+#include <unistd.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define EXPORT __attribute__((visibility("default")))
+
+static const char base64_enc_lut[] =
+	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+static const uint8_t base64_validation_lut[256] = {
+	['A'] = 1, ['B'] = 1, ['C'] = 1, ['D'] = 1,
+	['E'] = 1, ['F'] = 1, ['G'] = 1, ['H'] = 1,
+	['I'] = 1, ['J'] = 1, ['K'] = 1, ['L'] = 1,
+	['M'] = 1, ['N'] = 1, ['O'] = 1, ['P'] = 1,
+	['Q'] = 1, ['R'] = 1, ['S'] = 1, ['T'] = 1,
+	['U'] = 1, ['V'] = 1, ['W'] = 1, ['X'] = 1,
+	['Y'] = 1, ['Z'] = 1, ['a'] = 1, ['b'] = 1,
+	['c'] = 1, ['d'] = 1, ['e'] = 1, ['f'] = 1,
+	['g'] = 1, ['h'] = 1, ['i'] = 1, ['j'] = 1,
+	['k'] = 1, ['l'] = 1, ['m'] = 1, ['n'] = 1,
+	['o'] = 1, ['p'] = 1, ['q'] = 1, ['r'] = 1,
+	['s'] = 1, ['t'] = 1, ['u'] = 1, ['v'] = 1,
+	['w'] = 1, ['x'] = 1, ['y'] = 1, ['z'] = 1,
+	['0'] = 1, ['1'] = 1, ['2'] = 1, ['3'] = 1,
+	['4'] = 1, ['5'] = 1, ['6'] = 1, ['7'] = 1,
+	['8'] = 1, ['9'] = 1, ['+'] = 1, ['/'] = 1,
+	['-'] = 1, ['_'] = 1, ['='] = 1,
+};
+
+static const uint8_t base64_dec_lut[256] = {
+	['A'] = 0x00, ['B'] = 0x01, ['C'] = 0x02, ['D'] = 0x03,
+	['E'] = 0x04, ['F'] = 0x05, ['G'] = 0x06, ['H'] = 0x07,
+	['I'] = 0x08, ['J'] = 0x09, ['K'] = 0x0a, ['L'] = 0x0b,
+	['M'] = 0x0c, ['N'] = 0x0d, ['O'] = 0x0e, ['P'] = 0x0f,
+	['Q'] = 0x10, ['R'] = 0x11, ['S'] = 0x12, ['T'] = 0x13,
+	['U'] = 0x14, ['V'] = 0x15, ['W'] = 0x16, ['X'] = 0x17,
+	['Y'] = 0x18, ['Z'] = 0x19, ['a'] = 0x1a, ['b'] = 0x1b,
+	['c'] = 0x1c, ['d'] = 0x1d, ['e'] = 0x1e, ['f'] = 0x1f,
+	['g'] = 0x20, ['h'] = 0x21, ['i'] = 0x22, ['j'] = 0x23,
+	['k'] = 0x24, ['l'] = 0x25, ['m'] = 0x26, ['n'] = 0x27,
+	['o'] = 0x28, ['p'] = 0x29, ['q'] = 0x2a, ['r'] = 0x2b,
+	['s'] = 0x2c, ['t'] = 0x2d, ['u'] = 0x2e, ['v'] = 0x2f,
+	['w'] = 0x30, ['x'] = 0x31, ['y'] = 0x32, ['z'] = 0x33,
+	['0'] = 0x34, ['1'] = 0x35, ['2'] = 0x36, ['3'] = 0x37,
+	['4'] = 0x38, ['5'] = 0x39, ['6'] = 0x3a, ['7'] = 0x3b,
+	['8'] = 0x3c, ['9'] = 0x3d, ['+'] = 0x3e, ['/'] = 0x3f,
+	['-'] = 0x3e, ['_'] = 0x3f,
+};
+
+void base64_encode(char* dst, const uint8_t* src, size_t src_len)
+{
+	size_t i = 0;
+
+	for (; i < src_len / 3; ++i) {
+		uint32_t tmp = 0;
+		tmp |= (uint32_t)src[i * 3 + 0] << 16;
+		tmp |= (uint32_t)src[i * 3 + 1] << 8;
+		tmp |= (uint32_t)src[i * 3 + 2];
+
+		dst[i * 4 + 0] = base64_enc_lut[tmp >> 18];
+		dst[i * 4 + 1] = base64_enc_lut[(tmp >> 12) & 0x3f];
+		dst[i * 4 + 2] = base64_enc_lut[(tmp >> 6) & 0x3f];
+		dst[i * 4 + 3] = base64_enc_lut[tmp & 0x3f];
+	}
+
+	size_t rem = src_len % 3;
+	if (rem == 0) {
+		dst[i * 4] = '\0';
+		return;
+	}
+
+	uint32_t tmp = 0;
+	for (size_t r = 0; r < rem; ++r) {
+		size_t s = (2 - r) * 8;
+		tmp |= (uint32_t)src[i * 3 + r] << s;
+	}
+
+	size_t di = 0;
+	for (; di < rem + 1; ++di) {
+		size_t s = (3 - di) * 6;
+		dst[i * 4 + di] = base64_enc_lut[(tmp >> s) & 0x3f];
+	}
+
+	for (; di < 4; ++di) {
+		dst[i * 4 + di] = '=';
+	}
+
+	dst[i * 4 + di] = '\0';
+
+}
+
+static bool base64_is_valid(const char* src)
+{
+	for (int i = 0; src[i]; i++)
+		if (!base64_validation_lut[(uint8_t)src[i]])
+			return false;
+	return true;
+}
+
+ssize_t base64_decode(uint8_t* dst, const char* src)
+{
+	if (!base64_is_valid(src))
+		return -1;
+
+	size_t src_len = strcspn(src, "=");
+	size_t i = 0;
+
+	for (; i < src_len / 4; ++i) {
+		uint32_t tmp = 0;
+		tmp |= (uint32_t)base64_dec_lut[(uint8_t)src[i * 4 + 0]] << 18;
+		tmp |= (uint32_t)base64_dec_lut[(uint8_t)src[i * 4 + 1]] << 12;
+		tmp |= (uint32_t)base64_dec_lut[(uint8_t)src[i * 4 + 2]] << 6;
+		tmp |= (uint32_t)base64_dec_lut[(uint8_t)src[i * 4 + 3]];
+
+		dst[i * 3 + 0] = tmp >> 16;
+		dst[i * 3 + 1] = (tmp >> 8) & 0xff;
+		dst[i * 3 + 2] = tmp & 0xff;
+	}
+
+	size_t rem = src_len % 4;
+	if (rem == 0)
+		return i * 3;
+
+	size_t di = 0;
+
+	uint32_t tmp = 0;
+	for (size_t r = 0; r < rem; ++r) {
+		size_t s = (3 - r) * 6;
+		tmp |= (uint32_t)base64_dec_lut[(uint8_t)src[i * 4 + r]] << s;
+	}
+
+	for (; di < (rem * 3) / 4; ++di) {
+		size_t s = (2 - di) * 8;
+		dst[i * 3 + di] = (tmp >> s) & 0xff;
+	}
+
+	return i * 3 + di;
+}
+
+EXPORT
+void nvnc_base64_encode(char* dst, const uint8_t* src, size_t src_len)
+{
+	base64_encode(dst, src, src_len);
+}
+
+EXPORT
+ssize_t nvnc_base64_decode(uint8_t* dst, const char* src)
+{
+	return base64_decode(dst, src);
+}

src/crypto-nettle.c

@@ -0,0 +1,738 @@
+#include "crypto.h"
+#include "neatvnc.h"
+#include "vec.h"
+#include "base64.h"
+
+#include <gmp.h>
+#include <nettle/base64.h>
+#include <nettle/base16.h>
+#include <nettle/aes.h>
+#include <nettle/eax.h>
+#include <nettle/md5.h>
+#include <nettle/sha1.h>
+#include <nettle/sha.h>
+#include <nettle/rsa.h>
+
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <sys/param.h>
+#include <arpa/inet.h>
+
+// TODO: This is linux specific
+#include <sys/random.h>
+
+#define UDIV_UP(a, b) (((a) + (b) - 1) / (b))
+
+struct vec;
+
+struct crypto_key {
+	int g;
+	mpz_t p;
+	mpz_t q;
+};
+
+struct crypto_aes_eax {
+	struct eax_aes128_ctx ctx;
+	uint64_t count[2];
+};
+
+struct crypto_aes256_eax {
+	struct EAX_CTX(struct aes256_ctx) ctx;
+	uint64_t count[2];
+};
+
+struct crypto_cipher {
+	union {
+		struct aes128_ctx aes128_ecb;
+		struct crypto_aes_eax aes_eax;
+		struct crypto_aes256_eax aes256_eax;
+	} enc_ctx;
+
+	union {
+		struct aes128_ctx aes128_ecb;
+		struct crypto_aes_eax aes_eax;
+		struct crypto_aes256_eax aes256_eax;
+	} dec_ctx;
+
+	bool (*encrypt)(struct crypto_cipher*, struct vec* dst, uint8_t* mac,
+			const uint8_t* src, size_t src_len, const uint8_t* ad,
+			size_t ad_len);
+	ssize_t (*decrypt)(struct crypto_cipher*, uint8_t* dst, uint8_t* mac,
+			const uint8_t* src, size_t src_len, const uint8_t* ad,
+			size_t ad_len);
+};
+
+struct crypto_hash {
+	union {
+		struct md5_ctx md5;
+		struct sha1_ctx sha1;
+		struct sha256_ctx sha256;
+	} ctx;
+
+	void (*update)(void* ctx, size_t len, const uint8_t* src);
+	void (*digest)(void* ctx, size_t len, uint8_t* dst);
+};
+
+struct crypto_rsa_pub_key {
+	struct rsa_public_key key;
+};
+
+struct crypto_rsa_priv_key {
+	struct rsa_private_key key;
+};
+
+void crypto_dump_base64(const char* msg, const uint8_t* bytes, size_t len)
+{
+	struct base64_encode_ctx ctx = {};
+	size_t buflen = BASE64_ENCODE_LENGTH(len);
+	char* buffer = malloc(buflen + BASE64_ENCODE_FINAL_LENGTH + 1);
+	assert(buffer);
+	nettle_base64_encode_init(&ctx);
+	size_t count = nettle_base64_encode_update(&ctx, buffer, len, bytes);
+	count += nettle_base64_encode_final(&ctx, buffer + count);
+	buffer[count] = '\0';
+
+	nvnc_log(NVNC_LOG_DEBUG, "%s: %s", msg, buffer);
+	free(buffer);
+}
+
+void crypto_dump_base16(const char* msg, const uint8_t* bytes, size_t len)
+{
+	size_t buflen = BASE16_ENCODE_LENGTH(len);
+	char* buffer = calloc(1, buflen + 1);
+	assert(buffer);
+	nettle_base16_encode_update(buffer, len, bytes);
+
+	nvnc_log(NVNC_LOG_DEBUG, "%s: %s", msg, buffer);
+	free(buffer);
+}
+
+void crypto_random(uint8_t* dst, size_t len)
+{
+	getrandom(dst, len, 0);
+}
+
+static void crypto_import(mpz_t n, const uint8_t* src, size_t len)
+{
+	int order = 1;
+	int unit_size = 1;
+	int endian = 1;
+	int skip_bits = 0;
+
+	mpz_import(n, len, order, unit_size, endian, skip_bits, src);
+}
+
+struct crypto_key *crypto_key_new(int g, const uint8_t* p, uint32_t p_len,
+		const uint8_t* q, uint32_t q_len)
+{
+	struct crypto_key* self = calloc(1, sizeof(*self));
+	if (!self)
+		return NULL;
+
+	self->g = g;
+
+	mpz_init(self->p);
+	crypto_import(self->p, p, p_len);
+
+	mpz_init(self->q);
+	crypto_import(self->q, q, q_len);
+
+	return self;
+}
+
+void crypto_key_del(struct crypto_key* key)
+{
+	if (!key)
+		return;
+	mpz_clear(key->q);
+	mpz_clear(key->p);
+	free(key);
+}
+
+int crypto_key_g(const struct crypto_key* key)
+{
+	return key->g;
+}
+
+static size_t crypto_export(uint8_t* dst, size_t dst_size, const mpz_t n)
+{
+	int order = 1; // msb first
+	int unit_size = 1; // byte
+	int endian = 1; // msb first
+	int skip_bits = 0;
+
+	size_t bitsize = mpz_sizeinbase(n, 2);
+	size_t bytesize = (bitsize + 7) / 8;
+
+	assert(bytesize <= dst_size);
+
+	memset(dst, 0, dst_size);
+	mpz_export(dst + dst_size - bytesize, &bytesize, order, unit_size,
+			endian, skip_bits, n);
+
+	return bytesize;
+}
+
+uint32_t crypto_key_p(const struct crypto_key* key, uint8_t* dst,
+		uint32_t dst_size)
+{
+	return crypto_export(dst, dst_size, key->p);
+}
+
+uint32_t crypto_key_q(const struct crypto_key* key, uint8_t* dst,
+		uint32_t dst_size)
+{
+	return crypto_export(dst, dst_size, key->q);
+}
+
+static void initialise_p(mpz_t p)
+{
+	// RFC 3526, section 3
+	static const char s[] =
+		"FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD1"
+		"29024E088A67CC74020BBEA63B139B22514A08798E3404DD"
+		"EF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245"
+		"E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7ED"
+		"EE386BFB5A899FA5AE9F24117C4B1FE649286651ECE45B3D"
+		"C2007CB8A163BF0598DA48361C55D39A69163FA8FD24CF5F"
+		"83655D23DCA3AD961C62F356208552BB9ED529077096966D"
+		"670C354E4ABC9804F1746C08CA18217C32905E462E36CE3B"
+		"E39E772C180E86039B2783A2EC07A28FB5C55DF06F4C52C9"
+		"DE2BCBF6955817183995497CEA956AE515D2261898FA0510"
+		"15728E5A8AACAA68FFFFFFFFFFFFFFFF";
+
+	char buf[256];
+	size_t len = 0;
+	struct base16_decode_ctx ctx;
+	nettle_base16_decode_init(&ctx);
+	nettle_base16_decode_update(&ctx, &len, (uint8_t*)buf, sizeof(s) - 1, s);
+	nettle_base16_decode_final(&ctx);
+	assert(len == sizeof(buf));
+
+	crypto_import(p, (const uint8_t*)buf, sizeof(buf));
+}
+
+static void generate_random(mpz_t n)
+{
+	uint8_t buf[256];
+	getrandom(buf, sizeof(buf), 0);
+	crypto_import(n, buf, sizeof(buf));
+}
+
+struct crypto_key* crypto_keygen(void)
+{
+	struct crypto_key* self = calloc(1, sizeof(*self));
+	if (!self)
+		return NULL;
+
+	self->g = 2;
+
+	mpz_init(self->p);
+	initialise_p(self->p);
+
+	mpz_init(self->q);
+	generate_random(self->q);
+
+	return self;
+}
+
+struct crypto_key* crypto_derive_public_key(const struct crypto_key* priv)
+{
+	struct crypto_key* pub = calloc(1, sizeof(*pub));
+	if (!pub)
+		return NULL;
+
+	pub->g = priv->g;
+	mpz_set(pub->p, priv->p);
+	mpz_init(pub->q);
+
+	mpz_t g;
+	mpz_init(g);
+	mpz_set_ui(g, priv->g);
+
+	mpz_powm_sec(pub->q, g, priv->q, priv->p);
+	mpz_clear(g);
+
+	return pub;
+}
+
+struct crypto_key* crypto_derive_shared_secret(
+		const struct crypto_key* own_secret,
+		const struct crypto_key* remote_public_key)
+{
+	if (own_secret->g != remote_public_key->g) {
+		return NULL;
+	}
+
+	if (mpz_cmp(own_secret->p, remote_public_key->p) != 0) {
+		return NULL;
+	}
+
+	struct crypto_key* shared = calloc(1, sizeof(*shared));
+	if (!shared)
+		return NULL;
+
+	shared->g = own_secret->g;
+	mpz_set(shared->p, own_secret->p);
+
+	mpz_t g;
+	mpz_init(g);
+	mpz_set_ui(g, own_secret->g);
+
+	mpz_powm_sec(shared->q, remote_public_key->q, own_secret->q,
+			own_secret->p);
+	mpz_clear(g);
+
+	return shared;
+}
+
+static bool crypto_cipher_aes128_ecb_encrypt(struct crypto_cipher* self,
+		struct vec* dst, uint8_t* mac, const uint8_t* src,
+		size_t len, const uint8_t* ad, size_t ad_len)
+{
+	vec_reserve(dst, dst->len + len);
+	aes128_encrypt(&self->enc_ctx.aes128_ecb, len, dst->data, src);
+	dst->len = len;
+	return true;
+}
+
+static ssize_t crypto_cipher_aes128_ecb_decrypt(struct crypto_cipher* self,
+		uint8_t* dst, uint8_t* mac, const uint8_t* src, size_t len,
+		const uint8_t* ad, size_t ad_len)
+{
+	aes128_decrypt(&self->dec_ctx.aes128_ecb, len, dst, src);
+	return len;
+}
+
+static struct crypto_cipher* crypto_cipher_new_aes128_ecb(
+		const uint8_t* enc_key, const uint8_t* dec_key)
+{
+	struct crypto_cipher* self = calloc(1, sizeof(*self));
+	if (!self)
+		return NULL;
+
+	if (enc_key)
+		aes128_set_encrypt_key(&self->enc_ctx.aes128_ecb, enc_key);
+
+	if (dec_key)
+		aes128_set_decrypt_key(&self->enc_ctx.aes128_ecb, dec_key);
+
+	self->encrypt = crypto_cipher_aes128_ecb_encrypt;
+	self->decrypt = crypto_cipher_aes128_ecb_decrypt;
+
+	return self;
+}
+
+static void crypto_aes_eax_update_nonce(struct crypto_aes_eax* self)
+{
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+	nettle_eax_aes128_set_nonce(&self->ctx, 16, (const uint8_t*)self->count);
+#else
+	uint64_t c[2];
+	c[0] = __builtin_bswap64(self->count[0]);
+	c[1] = __builtin_bswap64(self->count[1]);
+	nettle_eax_aes128_set_nonce(&self->ctx, 16, (const uint8_t*)c);
+#endif
+
+	if (++self->count[0] == 0)
+		++self->count[1];
+}
+
+static bool crypto_cipher_aes_eax_encrypt(struct crypto_cipher* self,
+		struct vec* dst, uint8_t* mac, const uint8_t* src,
+		size_t src_len, const uint8_t* ad, size_t ad_len)
+{
+	vec_reserve(dst, dst->len + src_len);
+
+	crypto_aes_eax_update_nonce(&self->enc_ctx.aes_eax);
+	nettle_eax_aes128_update(&self->enc_ctx.aes_eax.ctx, ad_len,
+			(uint8_t*)ad);
+	nettle_eax_aes128_encrypt(&self->enc_ctx.aes_eax.ctx, src_len,
+			(uint8_t*)dst->data + dst->len, src);
+	dst->len += src_len;
+
+	nettle_eax_aes128_digest(&self->enc_ctx.aes_eax.ctx, 16, mac);
+
+	return true;
+}
+
+static ssize_t crypto_cipher_aes_eax_decrypt(struct crypto_cipher* self,
+		uint8_t* dst, uint8_t* mac, const uint8_t* src, size_t len,
+		const uint8_t* ad, size_t ad_len)
+{
+	crypto_aes_eax_update_nonce(&self->dec_ctx.aes_eax);
+	nettle_eax_aes128_update(&self->dec_ctx.aes_eax.ctx, ad_len, ad);
+	nettle_eax_aes128_decrypt(&self->dec_ctx.aes_eax.ctx, len, dst, src);
+	nettle_eax_aes128_digest(&self->dec_ctx.aes_eax.ctx, 16, mac);
+	return len;
+}
+
+static struct crypto_cipher* crypto_cipher_new_aes_eax(const uint8_t* enc_key,
+		const uint8_t* dec_key)
+{
+	struct crypto_cipher* self = calloc(1, sizeof(*self));
+	if (!self)
+		return NULL;
+
+	eax_aes128_set_key(&self->enc_ctx.aes_eax.ctx, enc_key);
+	eax_aes128_set_key(&self->dec_ctx.aes_eax.ctx, dec_key);
+
+	self->encrypt = crypto_cipher_aes_eax_encrypt;
+	self->decrypt = crypto_cipher_aes_eax_decrypt;
+
+	return self;
+}
+
+static void crypto_aes256_eax_update_nonce(struct crypto_aes256_eax* self)
+{
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+	EAX_SET_NONCE(&self->ctx, aes256_encrypt, 16, (const uint8_t*)self->count);
+#else
+	uint64_t c[2];
+	c[0] = __builtin_bswap64(self->count[0]);
+	c[1] = __builtin_bswap64(self->count[1]);
+	EAX_SET_NONCE(&self->ctx, aes256_encrypt, 16, (const uint8_t*)c);
+#endif
+
+	if (++self->count[0] == 0)
+		++self->count[1];
+}
+
+static bool crypto_cipher_aes256_eax_encrypt(struct crypto_cipher* self,
+		struct vec* dst, uint8_t* mac, const uint8_t* src,
+		size_t src_len, const uint8_t* ad, size_t ad_len)
+{
+	vec_reserve(dst, dst->len + src_len);
+
+	crypto_aes256_eax_update_nonce(&self->enc_ctx.aes256_eax);
+
+	EAX_UPDATE(&self->enc_ctx.aes256_eax.ctx, aes256_encrypt, ad_len, ad);
+	EAX_ENCRYPT(&self->enc_ctx.aes256_eax.ctx, aes256_encrypt, src_len,
+			(uint8_t*)dst->data + dst->len, src);
+	dst->len += src_len;
+
+	EAX_DIGEST(&self->enc_ctx.aes256_eax.ctx, aes256_encrypt, 16, mac);
+
+	return true;
+}
+
+static ssize_t crypto_cipher_aes256_eax_decrypt(struct crypto_cipher* self,
+		uint8_t* dst, uint8_t* mac, const uint8_t* src, size_t len,
+		const uint8_t* ad, size_t ad_len)
+{
+	crypto_aes256_eax_update_nonce(&self->dec_ctx.aes256_eax);
+	EAX_UPDATE(&self->dec_ctx.aes256_eax.ctx, aes256_encrypt, ad_len, ad);
+	EAX_DECRYPT(&self->dec_ctx.aes256_eax.ctx, aes256_encrypt, len, dst, src);
+	EAX_DIGEST(&self->dec_ctx.aes256_eax.ctx, aes256_encrypt, 16, mac);
+	return len;
+}
+
+static struct crypto_cipher* crypto_cipher_new_aes256_eax(const uint8_t* enc_key,
+		const uint8_t* dec_key)
+{
+	struct crypto_cipher* self = calloc(1, sizeof(*self));
+	if (!self)
+		return NULL;
+
+	EAX_SET_KEY(&self->enc_ctx.aes256_eax.ctx, aes256_set_encrypt_key,
+			aes256_encrypt, enc_key);
+	EAX_SET_KEY(&self->dec_ctx.aes256_eax.ctx, aes256_set_encrypt_key,
+			aes256_encrypt, dec_key);
+
+	self->encrypt = crypto_cipher_aes256_eax_encrypt;
+	self->decrypt = crypto_cipher_aes256_eax_decrypt;
+
+	return self;
+}
+
+struct crypto_cipher* crypto_cipher_new(const uint8_t* enc_key,
+		const uint8_t* dec_key, enum crypto_cipher_type type)
+{
+	switch (type) {
+	case CRYPTO_CIPHER_AES128_ECB:
+		return crypto_cipher_new_aes128_ecb(enc_key, dec_key);
+	case CRYPTO_CIPHER_AES_EAX:
+		return crypto_cipher_new_aes_eax(enc_key, dec_key);
+	case CRYPTO_CIPHER_AES256_EAX:
+		return crypto_cipher_new_aes256_eax(enc_key, dec_key);
+	case CRYPTO_CIPHER_INVALID:
+		break;
+	}
+
+	nvnc_log(NVNC_LOG_PANIC, "Invalid type: %d", type);
+	return NULL;
+}
+
+void crypto_cipher_del(struct crypto_cipher* self)
+{
+	free(self);
+}
+
+bool crypto_cipher_encrypt(struct crypto_cipher* self, struct vec* dst,
+		uint8_t* mac, const uint8_t* src, size_t src_len,
+		const uint8_t* ad, size_t ad_len)
+{
+	return self->encrypt(self, dst, mac, src, src_len, ad, ad_len);
+}
+
+ssize_t crypto_cipher_decrypt(struct crypto_cipher* self, uint8_t* dst,
+		uint8_t* mac, const uint8_t* src, size_t src_len,
+		const uint8_t* ad, size_t ad_len)
+{
+	return self->decrypt(self, dst, mac, src, src_len, ad, ad_len);
+}
+
+struct crypto_hash* crypto_hash_new(enum crypto_hash_type type)
+{
+	struct crypto_hash* self = calloc(1, sizeof(*self));
+	if (!self)
+		return NULL;
+
+	switch (type) {
+	case CRYPTO_HASH_INVALID:
+		nvnc_log(NVNC_LOG_PANIC, "Invalid hash type");
+		break;
+	case CRYPTO_HASH_MD5:
+		md5_init(&self->ctx.md5);
+		self->update = (void*)nettle_md5_update;
+		self->digest = (void*)nettle_md5_digest;
+		break;
+	case CRYPTO_HASH_SHA1:
+		sha1_init(&self->ctx.sha1);
+		self->update = (void*)nettle_sha1_update;
+		self->digest = (void*)nettle_sha1_digest;
+		break;
+	case CRYPTO_HASH_SHA256:
+		sha256_init(&self->ctx.sha256);
+		self->update = (void*)nettle_sha256_update;
+		self->digest = (void*)nettle_sha256_digest;
+		break;
+	}
+
+	return self;
+}
+
+void crypto_hash_del(struct crypto_hash* self)
+{
+	free(self);
+}
+
+void crypto_hash_append(struct crypto_hash* self, const uint8_t* src,
+		size_t len)
+{
+	self->update(&self->ctx, len, src);
+}
+
+void crypto_hash_digest(struct crypto_hash* self, uint8_t* dst, size_t len)
+{
+	self->digest(&self->ctx, len, dst);
+}
+
+void crypto_hash_one(uint8_t* dst, size_t dst_len, enum crypto_hash_type type,
+		const uint8_t* src, size_t src_len)
+{
+	struct crypto_hash *hash = crypto_hash_new(type);
+	crypto_hash_append(hash, src, src_len);
+	crypto_hash_digest(hash, dst, dst_len);
+	crypto_hash_del(hash);
+}
+
+void crypto_hash_many(uint8_t* dst, size_t dst_len, enum crypto_hash_type type,
+		const struct crypto_data_entry *src)
+{
+	struct crypto_hash *hash = crypto_hash_new(type);
+	for (int i = 0; src[i].data && src[i].len; ++i)
+		crypto_hash_append(hash, src[i].data, src[i].len);
+	crypto_hash_digest(hash, dst, dst_len);
+	crypto_hash_del(hash);
+}
+
+struct crypto_rsa_pub_key *crypto_rsa_pub_key_new(void)
+{
+	struct crypto_rsa_pub_key* self = calloc(1, sizeof(*self));
+	if (!self)
+		return NULL;
+
+	rsa_public_key_init(&self->key);
+	return self;
+}
+
+void crypto_rsa_pub_key_del(struct crypto_rsa_pub_key* self)
+{
+	if (!self)
+		return;
+	rsa_public_key_clear(&self->key);
+	free(self);
+}
+
+struct crypto_rsa_pub_key* crypto_rsa_pub_key_import(const uint8_t* modulus,
+		const uint8_t* exponent, size_t size)
+{
+	struct crypto_rsa_pub_key* self = crypto_rsa_pub_key_new();
+	if (!self)
+		return NULL;
+
+	rsa_public_key_init(&self->key);
+	mpz_init(self->key.n);
+	crypto_import(self->key.n, modulus, size);
+	mpz_init(self->key.e);
+	crypto_import(self->key.e, exponent, size);
+	rsa_public_key_prepare(&self->key);
+
+	return self;
+}
+
+bool crypto_rsa_priv_key_import_pkcs1_der(struct crypto_rsa_priv_key* priv,
+		struct crypto_rsa_pub_key* pub, const uint8_t* key,
+		size_t size)
+{
+	return rsa_keypair_from_der(&pub->key, &priv->key, 0, size, key);
+}
+
+bool crypto_rsa_priv_key_load(struct crypto_rsa_priv_key* priv,
+		struct crypto_rsa_pub_key* pub, const char* path)
+{
+	FILE* stream = fopen(path, "r");
+	if (!stream) {
+		nvnc_log(NVNC_LOG_ERROR, "Could not open file: %m");
+		return false;
+	}
+
+	char* line = NULL;
+	size_t n = 0;
+	if (getline(&line, &n, stream) < 0) {
+		nvnc_log(NVNC_LOG_ERROR, "RSA private key file is not PEM");
+		return false;
+	}
+
+	char head[128];
+	strlcpy(head, line, sizeof(head));
+	char* end = strchr(head, '\n');
+	if (end)
+		*end = '\0';
+
+	nvnc_trace("Read PEM head: \"%s\"\n", head);
+
+	struct vec base64_der;
+	vec_init(&base64_der, 4096);
+
+	while (getline(&line, &n, stream) >= 0) {
+		if (strncmp(line, "-----END", 8) == 0)
+			break;
+
+
+		vec_append(&base64_der, line, strcspn(line, "\n"));
+	}
+	free(line);
+	fclose(stream);
+
+	vec_append_zero(&base64_der, 1);
+
+	uint8_t* der = malloc(BASE64_DECODED_MAX_SIZE(base64_der.len));
+	assert(der);
+	vec_destroy(&base64_der);
+
+	ssize_t der_len = base64_decode(der, base64_der.data);
+	if (der_len < 0) {
+		free(der);
+		return false;
+	}
+
+	bool ok = false;
+	if (strcmp(head, "-----BEGIN RSA PRIVATE KEY-----") == 0) {
+		ok = crypto_rsa_priv_key_import_pkcs1_der(priv, pub, der, der_len);
+	} else {
+		nvnc_log(NVNC_LOG_ERROR, "Unsupported RSA private key format");
+	}
+
+	nvnc_trace("Private key is %d bits long", priv->key.size * 8);
+
+	free(der);
+	return ok;
+}
+
+void crypto_rsa_pub_key_modulus(const struct crypto_rsa_pub_key* key,
+		uint8_t* dst, size_t dst_size)
+{
+	 crypto_export(dst, dst_size, key->key.n);
+}
+
+void crypto_rsa_pub_key_exponent(const struct crypto_rsa_pub_key* key,
+		uint8_t* dst, size_t dst_size)
+{
+	char* str = mpz_get_str(NULL, 16, key->key.e);
+	free(str);
+
+	crypto_export(dst, dst_size, key->key.e);
+}
+
+struct crypto_rsa_priv_key *crypto_rsa_priv_key_new(void)
+{
+	struct crypto_rsa_priv_key* self = calloc(1, sizeof(*self));
+	if (!self)
+		return NULL;
+
+	rsa_private_key_init(&self->key);
+	return self;
+}
+
+void crypto_rsa_priv_key_del(struct crypto_rsa_priv_key* self)
+{
+	if (!self)
+		return;
+	rsa_private_key_clear(&self->key);
+	free(self);
+}
+
+size_t crypto_rsa_pub_key_length(const struct crypto_rsa_pub_key* key)
+{
+	return key->key.size;
+}
+
+static void generate_random_for_rsa(void* random_ctx, size_t len, uint8_t* dst)
+{
+	getrandom(dst, len, 0);
+}
+
+bool crypto_rsa_keygen(struct crypto_rsa_pub_key* pub,
+		struct crypto_rsa_priv_key* priv)
+{
+	void* random_ctx = NULL;
+	nettle_random_func* random_func = generate_random_for_rsa;
+	void* progress_ctx = NULL;
+	nettle_progress_func* progress = NULL;
+
+	int rc = rsa_generate_keypair(&pub->key, &priv->key, random_ctx,
+			random_func, progress_ctx, progress, 2048, 30);
+	return rc != 0;
+}
+
+ssize_t crypto_rsa_encrypt(struct crypto_rsa_pub_key* pub, uint8_t* dst,
+		size_t dst_size, const uint8_t* src, size_t src_size)
+{
+	mpz_t ciphertext;
+	mpz_init(ciphertext);
+	int r = rsa_encrypt(&pub->key, NULL, generate_random_for_rsa,
+			src_size, src, ciphertext);
+	if (r == 0) {
+		mpz_clear(ciphertext);
+		return -1;
+	}
+	size_t len = crypto_export(dst, dst_size, ciphertext);
+	mpz_clear(ciphertext);
+	return len;
+}
+
+ssize_t crypto_rsa_decrypt(struct crypto_rsa_priv_key* priv, uint8_t* dst,
+		size_t dst_size, const uint8_t* src, size_t src_size)
+{
+	mpz_t ciphertext;
+	mpz_init(ciphertext);
+	crypto_import(ciphertext, src, src_size);
+	int r = rsa_decrypt(&priv->key, &dst_size, dst, ciphertext);
+	mpz_clear(ciphertext);
+	return r != 0 ? (ssize_t)dst_size : -1;
+}

src/server.c

@@ -54,6 +54,10 @@
 #include <gnutls/gnutls.h>
 #endif
 
+#ifdef HAVE_CRYPTO
+#include "crypto.h"
+#endif
+
 #ifndef DRM_FORMAT_INVALID
 #define DRM_FORMAT_INVALID 0
 #endif
@@ -63,6 +67,10 @@
 #endif
 
 #define DEFAULT_NAME "Neat VNC"
+#define SECURITY_TYPES_MAX 3
+#define APPLE_DH_SERVER_KEY_LENGTH 256
+
+#define UDIV_UP(a, b) (((a) + (b) - 1) / (b))
 
 #define EXPORT __attribute__((visibility("default")))
 
@@ -119,6 +127,11 @@ static void client_close(struct nvnc_client* client)
 		nvnc_fb_unref(client->current_fb);
 	}
 
+#ifdef HAVE_CRYPTO
+	crypto_key_del(client->apple_dh_secret);
+	crypto_rsa_pub_key_del(client->rsa.pub);
+#endif
+
 	LIST_REMOVE(client, link);
 	stream_destroy(client->net_stream);
 	if (client->encoder) {
@@ -196,6 +209,8 @@ static int handle_unsupported_version(struct nvnc_client* client)
 
 static int on_version_message(struct nvnc_client* client)
 {
+	struct nvnc* server = client->server;
+
 	if (client->buffer_len - client->buffer_index < 12)
 		return 0;
 
@@ -206,17 +221,33 @@ static int on_version_message(struct nvnc_client* client)
 	if (strcmp(RFB_VERSION_MESSAGE, version_string) != 0)
 		return handle_unsupported_version(client);
 
-	struct rfb_security_types_msg security = { 0 };
+	uint8_t buf[sizeof(struct rfb_security_types_msg) +
-	security.n = 1;
+		SECURITY_TYPES_MAX] = {};
-	security.types[0] = RFB_SECURITY_TYPE_NONE;
+	struct rfb_security_types_msg* security =
+		(struct rfb_security_types_msg*)buf;
 
+	security->n = 0;
+	if (client->server->auth_fn) {
 #ifdef ENABLE_TLS
-	if (client->server->auth_fn)
+		if (server->tls_creds) {
-		security.types[0] = RFB_SECURITY_TYPE_VENCRYPT;
+			security->types[security->n++] = RFB_SECURITY_TYPE_VENCRYPT;
+		}
 #endif
 
-	stream_write(client->net_stream, &security, sizeof(security), NULL,
+#ifdef HAVE_CRYPTO
-	             NULL);
+		security->types[security->n++] = RFB_SECURITY_TYPE_RSA_AES256;
+		security->types[security->n++] = RFB_SECURITY_TYPE_RSA_AES;
+		security->types[security->n++] = RFB_SECURITY_TYPE_APPLE_DH;
+#endif
+	}
+
+	if (security->n == 0) {
+		security->n = 1;
+		security->types[0] = RFB_SECURITY_TYPE_NONE;
+	}
+
+	stream_write(client->net_stream, security, sizeof(*security) +
+			security->n, NULL, NULL);
 
 	client->state = VNC_CLIENT_STATE_WAITING_FOR_SECURITY;
 	return 12;
@@ -368,12 +399,380 @@ static int on_vencrypt_plain_auth_message(struct nvnc_client* client)
 }
 #endif
 
+#ifdef HAVE_CRYPTO
+static int apple_dh_send_public_key(struct nvnc_client* client)
+{
+	client->apple_dh_secret = crypto_keygen();
+	assert(client->apple_dh_secret);
+
+	struct crypto_key* pub =
+		crypto_derive_public_key(client->apple_dh_secret);
+	assert(pub);
+
+	uint8_t mod[APPLE_DH_SERVER_KEY_LENGTH] = {};
+	int mod_len = crypto_key_p(pub, mod, sizeof(mod));
+	assert(mod_len == sizeof(mod));
+
+	uint8_t q[APPLE_DH_SERVER_KEY_LENGTH] = {};
+	int q_len = crypto_key_q(pub, q, sizeof(q));
+	assert(q_len == sizeof(q));
+
+	struct rfb_apple_dh_server_msg msg = {
+		.generator = htons(crypto_key_g(client->apple_dh_secret)),
+		.key_size = htons(q_len),
+	};
+
+	stream_write(client->net_stream, &msg, sizeof(msg), NULL, NULL);
+	stream_write(client->net_stream, mod, mod_len, NULL, NULL);
+	stream_write(client->net_stream, q, q_len, NULL, NULL);
+
+	crypto_key_del(pub);
+	return 0;
+}
+
+static int on_apple_dh_response(struct nvnc_client* client)
+{
+	struct nvnc* server = client->server;
+
+	struct rfb_apple_dh_client_msg* msg =
+	        (void*)(client->msg_buffer + client->buffer_index);
+
+	uint8_t p[APPLE_DH_SERVER_KEY_LENGTH];
+	int key_len = crypto_key_p(client->apple_dh_secret, p, sizeof(p));
+	assert(key_len == sizeof(p));
+
+	if (client->buffer_len - client->buffer_index < sizeof(*msg) + key_len)
+		return 0;
+
+	int g = crypto_key_g(client->apple_dh_secret);
+
+	struct crypto_key* remote_key = crypto_key_new(g, p, key_len,
+			msg->public_key, key_len);
+	assert(remote_key);
+
+	struct crypto_key* shared_secret =
+		crypto_derive_shared_secret(client->apple_dh_secret, remote_key);
+	assert(shared_secret);
+
+	uint8_t shared_buf[APPLE_DH_SERVER_KEY_LENGTH];
+	crypto_key_q(shared_secret, shared_buf, sizeof(shared_buf));
+	crypto_key_del(shared_secret);
+
+	uint8_t hash[16] = {};
+	crypto_hash_one(hash, sizeof(hash), CRYPTO_HASH_MD5, shared_buf,
+			sizeof(shared_buf));
+
+	struct crypto_cipher* cipher;
+	cipher = crypto_cipher_new(NULL, hash, CRYPTO_CIPHER_AES128_ECB);
+	assert(cipher);
+
+	char username[128] = {};
+	char* password = username + 64;
+
+	crypto_cipher_decrypt(cipher, (uint8_t*)username, NULL,
+			msg->encrypted_credentials, sizeof(username), NULL, 0);
+	username[63] = '\0';
+	username[127] = '\0';
+	crypto_cipher_del(cipher);
+
+	if (server->auth_fn(username, password, server->auth_ud)) {
+		nvnc_log(NVNC_LOG_INFO, "User \"%s\" authenticated", username);
+		security_handshake_ok(client);
+		client->state = VNC_CLIENT_STATE_WAITING_FOR_INIT;
+	} else {
+		nvnc_log(NVNC_LOG_INFO, "User \"%s\" rejected", username);
+		security_handshake_failed(client, "Invalid username or password");
+		crypto_cipher_del(cipher);
+	}
+
+	return sizeof(*msg) + key_len;
+}
+
+static int rsa_aes_send_public_key(struct nvnc_client* client)
+{
+	struct nvnc* server = client->server;
+
+	if (!server->rsa_priv) {
+		assert(!server->rsa_pub);
+
+		nvnc_log(NVNC_LOG_WARNING, "An RSA key has not been set. A new key will be generated.");
+
+		server->rsa_priv = crypto_rsa_priv_key_new();
+		server->rsa_pub = crypto_rsa_pub_key_new();
+
+		crypto_rsa_keygen(server->rsa_pub, server->rsa_priv);
+	}
+	assert(server->rsa_pub && server->rsa_priv);
+
+	size_t key_len = crypto_rsa_pub_key_length(server->rsa_pub);
+	size_t buf_len = sizeof(struct rfb_rsa_aes_pub_key_msg) + key_len * 2;
+
+	char* buffer = calloc(1, buf_len);
+	assert(buffer);
+	struct rfb_rsa_aes_pub_key_msg* msg =
+		(struct rfb_rsa_aes_pub_key_msg*)buffer;
+
+	uint8_t* modulus = msg->modulus_and_exponent;
+	uint8_t* exponent = msg->modulus_and_exponent + key_len;
+
+	msg->length = htonl(key_len * 8);
+	crypto_rsa_pub_key_modulus(server->rsa_pub, modulus, key_len);
+	crypto_rsa_pub_key_exponent(server->rsa_pub, exponent, key_len);
+
+	stream_send(client->net_stream, rcbuf_new(buffer, buf_len), NULL, NULL);
+	return 0;
+}
+
+static int rsa_aes_send_challenge(struct nvnc_client* client,
+		struct crypto_rsa_pub_key* pub)
+{
+	crypto_random(client->rsa.challenge, client->rsa.challenge_len);
+
+	uint8_t buffer[1024];
+	struct rfb_rsa_aes_challenge_msg *msg =
+		(struct rfb_rsa_aes_challenge_msg*)buffer;
+
+	ssize_t len = crypto_rsa_encrypt(pub, msg->challenge,
+			crypto_rsa_pub_key_length(client->rsa.pub),
+			client->rsa.challenge, client->rsa.challenge_len);
+	msg->length = htons(len);
+
+	stream_write(client->net_stream, buffer, sizeof(*msg) + len, NULL, NULL);
+	return 0;
+}
+
+static int on_rsa_aes_public_key(struct nvnc_client* client)
+{
+	struct rfb_rsa_aes_pub_key_msg* msg =
+	        (void*)(client->msg_buffer + client->buffer_index);
+
+	if (client->buffer_len - client->buffer_index < sizeof(*msg))
+		return 0;
+
+	uint32_t bit_length = ntohl(msg->length);
+	size_t byte_length = UDIV_UP(bit_length, 8);
+
+	if (client->buffer_len - client->buffer_index <
+			sizeof(*msg) + byte_length * 2)
+		return 0;
+
+	const uint8_t* modulus = msg->modulus_and_exponent;
+	const uint8_t* exponent = msg->modulus_and_exponent + byte_length;
+
+	client->rsa.pub =
+		crypto_rsa_pub_key_import(modulus, exponent, byte_length);
+	assert(client->rsa.pub);
+
+	client->state = VNC_CLIENT_STATE_WAITING_FOR_RSA_AES_CHALLENGE;
+	rsa_aes_send_challenge(client, client->rsa.pub);
+
+	return sizeof(*msg) + byte_length * 2;
+}
+
+static size_t client_rsa_aes_hash_len(const struct nvnc_client* client)
+{
+	switch (client->rsa.hash_type) {
+	case CRYPTO_HASH_SHA1: return 20;
+	case CRYPTO_HASH_SHA256: return 32;
+	default:;
+	}
+	abort();
+	return 0;
+}
+
+static int on_rsa_aes_challenge(struct nvnc_client* client)
+{
+	struct rfb_rsa_aes_challenge_msg* msg =
+	        (void*)(client->msg_buffer + client->buffer_index);
+
+	if (client->buffer_len - client->buffer_index < sizeof(*msg))
+		return 0;
+
+	uint16_t length = ntohs(msg->length);
+	if (client->buffer_len - client->buffer_index < sizeof(*msg) + length)
+		return 0;
+
+	struct nvnc* server = client->server;
+
+	uint8_t client_random[32] = {};
+	ssize_t len = crypto_rsa_decrypt(server->rsa_priv, client_random,
+			client->rsa.challenge_len, msg->challenge, length);
+	if (len < 0) {
+		nvnc_log(NVNC_LOG_ERROR, "Failed to decrypt client's challenge");
+		client->state = VNC_CLIENT_STATE_ERROR;
+		nvnc_client_close(client);
+		goto done;
+	}
+
+	// ClientSessionKey = the first 16 bytes of SHA1(ServerRandom || ClientRandom)
+	uint8_t client_session_key[32];
+	crypto_hash_many(client_session_key, client_rsa_aes_hash_len(client),
+			client->rsa.hash_type, (const struct crypto_data_entry[]) {
+		{ client->rsa.challenge, client->rsa.challenge_len },
+		{ client_random, client->rsa.challenge_len },
+		{}
+	});
+
+	// ServerSessionKey = the first 16 bytes of SHA1(ClientRandom || ServerRandom)
+	uint8_t server_session_key[32];
+	crypto_hash_many(server_session_key, client_rsa_aes_hash_len(client),
+			client->rsa.hash_type, (const struct crypto_data_entry[]) {
+		{ client_random, client->rsa.challenge_len },
+		{ client->rsa.challenge, client->rsa.challenge_len },
+		{}
+	});
+
+	stream_upgrade_to_rsa_eas(client->net_stream, client->rsa.cipher_type,
+			server_session_key, client_session_key);
+
+	size_t server_key_len = crypto_rsa_pub_key_length(server->rsa_pub);
+	uint8_t* server_modulus = malloc(server_key_len * 2);
+	uint8_t* server_exponent = server_modulus + server_key_len;
+
+	crypto_rsa_pub_key_modulus(server->rsa_pub, server_modulus,
+			server_key_len);
+	crypto_rsa_pub_key_exponent(server->rsa_pub, server_exponent,
+			server_key_len);
+
+	size_t client_key_len = crypto_rsa_pub_key_length(client->rsa.pub);
+	uint8_t* client_modulus = malloc(client_key_len * 2);
+	uint8_t* client_exponent = client_modulus + client_key_len;
+
+	crypto_rsa_pub_key_modulus(client->rsa.pub, client_modulus,
+			client_key_len);
+	crypto_rsa_pub_key_exponent(client->rsa.pub, client_exponent,
+			client_key_len);
+
+	uint32_t server_key_len_be = htonl(server_key_len * 8);
+	uint32_t client_key_len_be = htonl(client_key_len * 8);
+
+	uint8_t server_hash[32] = {};
+	crypto_hash_many(server_hash, client_rsa_aes_hash_len(client),
+			client->rsa.hash_type, (const struct crypto_data_entry[]) {
+		{ (uint8_t*)&server_key_len_be, 4 },
+		{ server_modulus, server_key_len },
+		{ server_exponent, server_key_len },
+		{ (uint8_t*)&client_key_len_be, 4 },
+		{ client_modulus, client_key_len },
+		{ client_exponent, client_key_len },
+		{}
+	});
+
+	free(server_modulus);
+	free(client_modulus);
+
+	stream_write(client->net_stream, server_hash,
+			client_rsa_aes_hash_len(client), NULL, NULL);
+
+	client->state = VNC_CLIENT_STATE_WAITING_FOR_RSA_AES_CLIENT_HASH;
+done:
+	return sizeof(*msg) + length;
+}
+
+static int on_rsa_aes_client_hash(struct nvnc_client* client)
+{
+	const char* msg = (void*)(client->msg_buffer + client->buffer_index);
+
+	if (client->buffer_len - client->buffer_index < client_rsa_aes_hash_len(client))
+		return 0;
+
+	struct nvnc* server = client->server;
+
+	size_t server_key_len = crypto_rsa_pub_key_length(server->rsa_pub);
+	uint8_t* server_modulus = malloc(server_key_len * 2);
+	uint8_t* server_exponent = server_modulus + server_key_len;
+	crypto_rsa_pub_key_modulus(server->rsa_pub, server_modulus,
+			server_key_len);
+	crypto_rsa_pub_key_exponent(server->rsa_pub, server_exponent,
+			server_key_len);
+
+	size_t client_key_len = crypto_rsa_pub_key_length(client->rsa.pub);
+	uint8_t* client_modulus = malloc(client_key_len * 2);
+	uint8_t* client_exponent = client_modulus + client_key_len;
+
+	crypto_rsa_pub_key_modulus(client->rsa.pub, client_modulus,
+			client_key_len);
+	crypto_rsa_pub_key_exponent(client->rsa.pub, client_exponent,
+			client_key_len);
+
+	uint32_t server_key_len_be = htonl(server_key_len * 8);
+	uint32_t client_key_len_be = htonl(client_key_len * 8);
+
+	uint8_t client_hash[32] = {};
+	crypto_hash_many(client_hash, client_rsa_aes_hash_len(client),
+			client->rsa.hash_type, (const struct crypto_data_entry[]) {
+		{ (uint8_t*)&client_key_len_be, 4 },
+		{ client_modulus, client_key_len },
+		{ client_exponent, client_key_len },
+		{ (uint8_t*)&server_key_len_be, 4 },
+		{ server_modulus, server_key_len },
+		{ server_exponent, server_key_len },
+		{}
+	});
+
+	free(client_modulus);
+	free(server_modulus);
+
+	if (memcmp(msg, client_hash, client_rsa_aes_hash_len(client)) != 0) {
+		nvnc_log(NVNC_LOG_INFO, "Client hash mismatch");
+		nvnc_client_close(client);
+		return 0;
+	}
+
+	// TODO: Read this from config
+	uint8_t subtype = RFB_RSA_AES_CRED_SUBTYPE_USER_AND_PASS;
+	stream_write(client->net_stream, &subtype, 1, NULL, NULL);
+
+	client->state = VNC_CLIENT_STATE_WAITING_FOR_RSA_AES_CREDENTIALS;
+	return client_rsa_aes_hash_len(client);
+}
+
+static int on_rsa_aes_credentials(struct nvnc_client* client)
+{
+	const uint8_t* msg = (void*)(client->msg_buffer + client->buffer_index);
+
+	if (client->buffer_len - client->buffer_index < 2)
+		return 0;
+
+	size_t username_len = msg[0];
+	if (client->buffer_len - client->buffer_index < 2 + username_len)
+		return 0;
+
+	size_t password_len = msg[1 + username_len];
+	if (client->buffer_len - client->buffer_index < 2 + username_len +
+			password_len)
+		return 0;
+
+	struct nvnc* server = client->server;
+
+	char username[256];
+	char password[256];
+
+	strlcpy(username, (const char*)(msg + 1), username_len + 1);
+	strlcpy(password, (const char*)(msg + 2 + username_len),
+			password_len + 1);
+
+	if (server->auth_fn(username, password, server->auth_ud)) {
+		nvnc_log(NVNC_LOG_INFO, "User \"%s\" authenticated", username);
+		security_handshake_ok(client);
+		client->state = VNC_CLIENT_STATE_WAITING_FOR_INIT;
+	} else {
+		nvnc_log(NVNC_LOG_INFO, "User \"%s\" rejected", username);
+		security_handshake_failed(client, "Invalid username or password");
+	}
+
+	return 2 + username_len + password_len;
+}
+
+#endif // HAVE_CRYPTO
+
 static int on_security_message(struct nvnc_client* client)
 {
 	if (client->buffer_len - client->buffer_index < 1)
 		return 0;
 
 	uint8_t type = client->msg_buffer[client->buffer_index];
+	nvnc_log(NVNC_LOG_DEBUG, "Client chose security type: %d", type);
 
 	switch (type) {
 	case RFB_SECURITY_TYPE_NONE:
@@ -385,6 +784,26 @@ static int on_security_message(struct nvnc_client* client)
 		vencrypt_send_version(client);
 		client->state = VNC_CLIENT_STATE_WAITING_FOR_VENCRYPT_VERSION;
 		break;
+#endif
+#ifdef HAVE_CRYPTO
+	case RFB_SECURITY_TYPE_APPLE_DH:
+		apple_dh_send_public_key(client);
+		client->state = VNC_CLIENT_STATE_WAITING_FOR_APPLE_DH_RESPONSE;
+		break;
+	case RFB_SECURITY_TYPE_RSA_AES:
+		client->rsa.hash_type = CRYPTO_HASH_SHA1;
+		client->rsa.cipher_type = CRYPTO_CIPHER_AES_EAX;
+		client->rsa.challenge_len = 16;
+		rsa_aes_send_public_key(client);
+		client->state = VNC_CLIENT_STATE_WAITING_FOR_RSA_AES_PUBLIC_KEY;
+		break;
+	case RFB_SECURITY_TYPE_RSA_AES256:
+		client->rsa.hash_type = CRYPTO_HASH_SHA256;
+		client->rsa.cipher_type = CRYPTO_CIPHER_AES256_EAX;
+		client->rsa.challenge_len = 32;
+		rsa_aes_send_public_key(client);
+		client->state = VNC_CLIENT_STATE_WAITING_FOR_RSA_AES_PUBLIC_KEY;
+		break;
 #endif
 	default:
 		security_handshake_failed(client, "Unsupported security type");
@@ -1165,6 +1584,18 @@ static int try_read_client_message(struct nvnc_client* client)
 		return on_vencrypt_subtype_message(client);
 	case VNC_CLIENT_STATE_WAITING_FOR_VENCRYPT_PLAIN_AUTH:
 		return on_vencrypt_plain_auth_message(client);
+#endif
+#ifdef HAVE_CRYPTO
+	case VNC_CLIENT_STATE_WAITING_FOR_APPLE_DH_RESPONSE:
+		return on_apple_dh_response(client);
+	case VNC_CLIENT_STATE_WAITING_FOR_RSA_AES_PUBLIC_KEY:
+		return on_rsa_aes_public_key(client);
+	case VNC_CLIENT_STATE_WAITING_FOR_RSA_AES_CHALLENGE:
+		return on_rsa_aes_challenge(client);
+	case VNC_CLIENT_STATE_WAITING_FOR_RSA_AES_CLIENT_HASH:
+		return on_rsa_aes_client_hash(client);
+	case VNC_CLIENT_STATE_WAITING_FOR_RSA_AES_CREDENTIALS:
+		return on_rsa_aes_credentials(client);
 #endif
 	case VNC_CLIENT_STATE_READY:
 		return on_client_message(client);
@@ -1909,6 +2340,16 @@ cert_alloc_failure:
 	return -1;
 }
 
+EXPORT
+int nvnc_enable_auth2(struct nvnc* self, nvnc_auth_fn auth_fn, void* userdata)
+{
+#ifdef HAVE_CRYPTO
+	self->auth_fn = auth_fn;
+	return 0;
+#endif
+	return -1;
+}
+
 EXPORT
 void nvnc_set_cursor(struct nvnc* self, struct nvnc_fb* fb, uint16_t width,
 		uint16_t height, uint16_t hotspot_x, uint16_t hotspot_y,
@@ -1947,3 +2388,19 @@ void nvnc_set_cursor(struct nvnc* self, struct nvnc_fb* fb, uint16_t width,
 	LIST_FOREACH(client, &self->clients, link)
 		process_fb_update_requests(client);
 }
+
+EXPORT
+int nvnc_set_rsa_creds(struct nvnc* self, const char* path)
+{
+#ifdef HAVE_CRYPTO
+	crypto_rsa_priv_key_del(self->rsa_priv);
+	crypto_rsa_pub_key_del(self->rsa_pub);
+
+	self->rsa_priv = crypto_rsa_priv_key_new();
+	self->rsa_pub = crypto_rsa_pub_key_new();
+
+	bool ok = crypto_rsa_priv_key_load(self->rsa_priv, self->rsa_pub, path);
+	return ok ? 0 : -1;
+#endif
+	return -1;
+}

src/stream-gnutls.c

@@ -82,6 +82,8 @@ static int stream_gnutls__flush(struct stream* base)
 {
 	struct stream_gnutls* self = (struct stream_gnutls*)base;
 	while (!TAILQ_EMPTY(&self->base.send_queue)) {
+		assert(self->base.state != STREAM_STATE_CLOSED);
+
 		struct stream_req* req = TAILQ_FIRST(&self->base.send_queue);
 
 		ssize_t rc = gnutls_record_send(self->session,

src/stream-rsa-aes.c

@@ -0,0 +1,208 @@
+/*
+ * Copyright (c) 2023 Andri Yngvason
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <assert.h>
+#include <errno.h>
+#include <sys/param.h>
+#include <arpa/inet.h>
+
+#include "rcbuf.h"
+#include "stream.h"
+#include "stream-tcp.h"
+#include "stream-common.h"
+#include "crypto.h"
+#include "neatvnc.h"
+
+#define RSA_AES_BUFFER_SIZE 8192
+#define UDIV_UP(a, b) (((a) + (b) - 1) / (b))
+
+struct stream_rsa_aes {
+	struct stream base;
+
+	size_t read_index;
+	uint8_t* read_buffer;
+
+	struct crypto_cipher* cipher;
+};
+
+static_assert(sizeof(struct stream_rsa_aes) <= STREAM_ALLOC_SIZE,
+		"struct stream_rsa_aes has grown too large, increase STREAM_ALLOC_SIZE");
+
+static void stream_rsa_aes_destroy(struct stream* base)
+{
+	struct stream_rsa_aes* self = (struct stream_rsa_aes*)base;
+	crypto_cipher_del(self->cipher);
+	free(self->read_buffer);
+	stream_tcp_destroy(base);
+}
+
+static void stream_rsa_aes_read_into_buffer(struct stream_rsa_aes* self)
+{
+	ssize_t n_read = stream_tcp_read(&self->base,
+			self->read_buffer + self->read_index,
+			RSA_AES_BUFFER_SIZE - self->read_index);
+	if (n_read > 0)
+		self->read_index += n_read;
+}
+
+static ssize_t stream_rsa_aes_parse_header(struct stream_rsa_aes* self)
+{
+	if (self->read_index <= 2) {
+		return -1;
+	}
+
+	uint16_t len_be;
+	memcpy(&len_be, self->read_buffer, sizeof(len_be));
+	size_t len = ntohs(len_be);
+
+	if (self->read_index < 2 + 16 + len) {
+		return -1;
+	}
+
+	return len;
+}
+
+static ssize_t stream_rsa_aes_read_message(struct stream_rsa_aes* self,
+		uint8_t* dst, size_t size)
+{
+	ssize_t msg_len = stream_rsa_aes_parse_header(self);
+	if (msg_len < 0) {
+		return 0;
+	}
+
+	// The entire message must fit in dst
+	/* TODO: With this, stream_tcp__on_event won't run until network input
+	 * is received. We need to somehow schedule on_event or also buffer the
+	 * decrypted data here.
+	 * Another option would be to keep back the message counter in the
+	 * cipher until the message has been fully read.
+	 */
+	if ((size_t)msg_len > size)
+		return 0;
+
+	uint16_t msg_len_be = htons(msg_len);
+
+	uint8_t expected_mac[16];
+	ssize_t n = crypto_cipher_decrypt(self->cipher, dst, expected_mac,
+			self->read_buffer + 2, msg_len,
+			(uint8_t*)&msg_len_be, sizeof(msg_len_be));
+
+	uint8_t* actual_mac = self->read_buffer + 2 + msg_len;
+	if (memcmp(expected_mac, actual_mac, 16) != 0) {
+		nvnc_log(NVNC_LOG_DEBUG, "Message authentication failed");
+		errno = EBADMSG;
+		return -1;
+	}
+
+	self->read_index -= 2 + 16 + msg_len;
+	memmove(self->read_buffer, self->read_buffer + 2 + 16 + msg_len,
+			self->read_index);
+
+	return n;
+}
+
+static ssize_t stream_rsa_aes_read(struct stream* base, void* dst, size_t size)
+{
+	struct stream_rsa_aes* self = (struct stream_rsa_aes*)base;
+
+	stream_rsa_aes_read_into_buffer(self);
+	if (self->base.state == STREAM_STATE_CLOSED)
+		return 0;
+
+	size_t total_read = 0;
+
+	while (true) {
+		ssize_t n_read = stream_rsa_aes_read_message(self, dst, size);
+		if (n_read == 0)
+			break;
+
+		if (n_read < 0) {
+			if (errno == EAGAIN) {
+				break;
+			}
+			return -1;
+		}
+
+		total_read += n_read;
+		dst += n_read;
+		size -= n_read;
+	}
+
+	return total_read;
+}
+
+static int stream_rsa_aes_send(struct stream* base, struct rcbuf* payload,
+                stream_req_fn on_done, void* userdata)
+{
+	struct stream_rsa_aes* self = (struct stream_rsa_aes*)base;
+	size_t n_msg = UDIV_UP(payload->size, RSA_AES_BUFFER_SIZE);
+
+	struct vec buf;
+	vec_init(&buf, payload->size + n_msg * (2 + 16));
+
+	for (size_t i = 0; i < n_msg; ++i) {
+		size_t msglen = MIN(payload->size - i * RSA_AES_BUFFER_SIZE,
+				RSA_AES_BUFFER_SIZE);
+		uint16_t msglen_be = htons(msglen);
+
+		vec_append(&buf, &msglen_be, sizeof(msglen_be));
+
+		uint8_t mac[16];
+		crypto_cipher_encrypt(self->cipher, &buf, mac,
+				payload->payload + i * RSA_AES_BUFFER_SIZE,
+				msglen, (uint8_t*)&msglen_be, sizeof(msglen_be));
+		vec_append(&buf, mac, sizeof(mac));
+	}
+
+	int r = stream_tcp_send(base, rcbuf_new(buf.data, buf.len), on_done,
+			userdata);
+	if (r < 0) {
+		return r;
+	}
+
+	return payload->size;
+}
+
+static struct stream_impl impl = {
+	.close = stream_tcp_close,
+	.destroy = stream_rsa_aes_destroy,
+	.read = stream_rsa_aes_read,
+	.send = stream_rsa_aes_send,
+};
+
+int stream_upgrade_to_rsa_eas(struct stream* base,
+		enum crypto_cipher_type cipher_type,
+		const uint8_t* enc_key, const uint8_t* dec_key)
+{
+	struct stream_rsa_aes* self = (struct stream_rsa_aes*)base;
+
+	self->read_index = 0;
+	self->read_buffer = malloc(RSA_AES_BUFFER_SIZE);
+	if (!self->read_buffer)
+		return -1;
+
+	self->cipher = crypto_cipher_new(enc_key, dec_key, cipher_type);
+	if (!self->cipher) {
+		free(self->read_buffer);
+		return -1;
+	}
+
+	self->base.impl = &impl;
+	return 0;
+}

src/stream-tcp.c

@@ -30,12 +30,14 @@
 #include "rcbuf.h"
 #include "stream.h"
 #include "stream-common.h"
+#include "stream-tcp.h"
 #include "sys/queue.h"
+#include "neatvnc.h"
 
 static_assert(sizeof(struct stream) <= STREAM_ALLOC_SIZE,
 		"struct stream has grown too large, increase STREAM_ALLOC_SIZE");
 
-static int stream_tcp_close(struct stream* self)
+int stream_tcp_close(struct stream* self)
 {
 	if (self->state == STREAM_STATE_CLOSED)
 		return -1;
@@ -55,8 +57,9 @@ static int stream_tcp_close(struct stream* self)
 	return 0;
 }
 
-static void stream_tcp_destroy(struct stream* self)
+void stream_tcp_destroy(struct stream* self)
 {
+	vec_destroy(&self->tmp_buf);
 	stream_close(self);
 	aml_unref(self->handler);
 	free(self);
@@ -76,7 +79,8 @@ static int stream_tcp__flush(struct stream* self)
 		if (req->exec) {
 			if (req->payload)
 				rcbuf_unref(req->payload);
-			req->payload = req->exec(self, req->userdata);
+			struct rcbuf* payload  = req->exec(self, req->userdata);
+			req->payload = payload;
 		}
 
 		iov[n_msgs].iov_base = req->payload->payload;
@@ -182,20 +186,28 @@ static void stream_tcp__on_event(void* obj)
 		stream_tcp__on_writable(self);
 }
 
-static ssize_t stream_tcp_read(struct stream* self, void* dst, size_t size)
+ssize_t stream_tcp_read(struct stream* self, void* dst, size_t size)
 {
 	if (self->state != STREAM_STATE_NORMAL)
 		return -1;
 
-	ssize_t rc = read(self->fd, dst, size);
+	uint8_t* read_buffer = dst;
+
+	if (self->cipher) {
+		vec_reserve(&self->tmp_buf, size);
+		read_buffer = self->tmp_buf.data;
+	}
+
+	ssize_t rc = read(self->fd, read_buffer, size);
 	if (rc == 0)
 		stream__remote_closed(self);
 	if (rc > 0)
 		self->bytes_received += rc;
+
 	return rc;
 }
 
-static int stream_tcp_send(struct stream* self, struct rcbuf* payload,
+int stream_tcp_send(struct stream* self, struct rcbuf* payload,
                 stream_req_fn on_done, void* userdata)
 {
 	if (self->state == STREAM_STATE_CLOSED)
@@ -214,7 +226,7 @@ static int stream_tcp_send(struct stream* self, struct rcbuf* payload,
 	return stream_tcp__flush(self);
 }
 
-static int stream_tcp_send_first(struct stream* self, struct rcbuf* payload)
+int stream_tcp_send_first(struct stream* self, struct rcbuf* payload)
 {
 	if (self->state == STREAM_STATE_CLOSED)
 		return -1;
@@ -229,7 +241,7 @@ static int stream_tcp_send_first(struct stream* self, struct rcbuf* payload)
 	return stream_tcp__flush(self);
 }
 
-static void stream_tcp_exec_and_send(struct stream* self,
+void stream_tcp_exec_and_send(struct stream* self,
 		stream_exec_fn exec_fn, void* userdata)
 {
 	if (self->state == STREAM_STATE_CLOSED)
@@ -256,12 +268,9 @@ static struct stream_impl impl = {
 	.exec_and_send = stream_tcp_exec_and_send,
 };
 
-struct stream* stream_new(int fd, stream_event_fn on_event, void* userdata)
+int stream_tcp_init(struct stream* self, int fd, stream_event_fn on_event,
+		void* userdata)
 {
-	struct stream* self = calloc(1, STREAM_ALLOC_SIZE);
-	if (!self)
-		return NULL;
-
 	self->impl = &impl,
 	self->fd = fd;
 	self->on_event = on_event;
@@ -273,19 +282,31 @@ struct stream* stream_new(int fd, stream_event_fn on_event, void* userdata)
 
 	self->handler = aml_handler_new(fd, stream_tcp__on_event, self, NULL);
 	if (!self->handler)
-		goto failure;
+		return -1;
 
 	if (aml_start(aml_get_default(), self->handler) < 0)
 		goto start_failure;
 
 	stream__poll_r(self);
 
-	return self;
+	return 0;
 
 start_failure:
 	aml_unref(self->handler);
-	self = NULL; /* Handled in unref */
+	return -1;
-failure:
+}
+
+struct stream* stream_new(int fd, stream_event_fn on_event, void* userdata)
+{
+	struct stream* self = calloc(1, STREAM_ALLOC_SIZE);
+	if (!self)
+		return NULL;
+
+	if (stream_tcp_init(self, fd, on_event, userdata) < 0) {
 		free(self);
 		return NULL;
 	}
+
+	return self;
+
+}

src/stream-ws.c

@@ -16,6 +16,7 @@
 
 #include "stream.h"
 #include "stream-common.h"
+#include "stream-tcp.h"
 #include "websocket.h"
 #include "vec.h"
 #include "neatvnc.h"
@@ -38,31 +39,17 @@ struct stream_ws_exec_ctx {
 
 struct stream_ws {
 	struct stream base;
+	stream_event_fn on_event;
 	enum stream_ws_state ws_state;
 	struct ws_frame_header header;
 	enum ws_opcode current_opcode;
-	uint8_t read_buffer[4096]; // TODO: Is this a reasonable size?
 	size_t read_index;
-	struct stream* tcp_stream;
+	uint8_t read_buffer[4096]; // TODO: Is this a reasonable size?
 };
 
-static int stream_ws_close(struct stream* self)
-{
-	struct stream_ws* ws = (struct stream_ws*)self;
-	self->state = STREAM_STATE_CLOSED;
-	return stream_close(ws->tcp_stream);
-}
-
-static void stream_ws_destroy(struct stream* self)
-{
-	struct stream_ws* ws = (struct stream_ws*)self;
-	stream_destroy(ws->tcp_stream);
-	free(self);
-}
-
 static void stream_ws_read_into_buffer(struct stream_ws* ws)
 {
-	ssize_t n_read = stream_read(ws->tcp_stream,
+	ssize_t n_read = stream_tcp_read(&ws->base,
 			ws->read_buffer + ws->read_index,
 			sizeof(ws->read_buffer) - ws->read_index);
 	if (n_read > 0)
@@ -104,14 +91,15 @@ static ssize_t stream_ws_process_ping(struct stream_ws* ws, size_t offset)
 
 		uint8_t buf[WS_HEADER_MIN_SIZE];
 		int reply_len = ws_write_frame_header(buf, &reply);
-		stream_write(ws->tcp_stream, buf, reply_len, NULL, NULL);
+		stream_tcp_send(&ws->base, rcbuf_from_mem(buf, reply_len),
+				NULL, NULL);
 	}
 
 	int payload_len = MIN(ws->read_index, ws->header.payload_length);
 
 	// Feed back the payload:
-	stream_write(ws->tcp_stream, ws->read_buffer + offset,
+	stream_tcp_send(&ws->base, rcbuf_from_mem(ws->read_buffer + offset,
-			payload_len, NULL, NULL);
+			payload_len), NULL, NULL);
 
 	stream_ws_advance_read_buffer(ws, payload_len, offset);
 	return 0;
@@ -124,7 +112,7 @@ static ssize_t stream_ws_process_payload(struct stream_ws* ws, void* dst,
 	case WS_OPCODE_CONT:
 		// Remote end started with a continuation frame. This is
 		// unexpected, so we'll just close.
-		stream__remote_closed(ws->tcp_stream);
+		stream__remote_closed(&ws->base);
 		return 0;
 	case WS_OPCODE_TEXT:
 		// This is unexpected, but let's just ignore it...
@@ -133,7 +121,7 @@ static ssize_t stream_ws_process_payload(struct stream_ws* ws, void* dst,
 	case WS_OPCODE_BIN:
 		return stream_ws_copy_payload(ws, dst, size, offset);
 	case WS_OPCODE_CLOSE:
-		stream__remote_closed(ws->tcp_stream);
+		stream__remote_closed(&ws->base);
 		return 0;
 	case WS_OPCODE_PING:
 		return stream_ws_process_ping(ws, offset);
@@ -213,8 +201,8 @@ static ssize_t stream_ws_read_handshake(struct stream_ws* ws, void* dst,
 	if (header_len < 0)
 		return 0;
 
-	ws->tcp_stream->cork = false;
+	ws->base.cork = false;
-	stream_send_first(ws->tcp_stream, rcbuf_from_mem(reply, strlen(reply)));
+	stream_tcp_send_first(&ws->base, rcbuf_from_mem(reply, strlen(reply)));
 
 	ws->read_index -= header_len;
 	memmove(ws->read_buffer, ws->read_buffer + header_len, ws->read_index);
@@ -255,18 +243,23 @@ static int stream_ws_send(struct stream* self, struct rcbuf* payload,
 	uint8_t raw_head[WS_HEADER_MIN_SIZE];
 	int head_len = ws_write_frame_header(raw_head, &head);
 
-	stream_write(ws->tcp_stream, &raw_head, head_len, NULL, NULL);
+	stream_tcp_send(&ws->base, rcbuf_from_mem(&raw_head, head_len),
-	return stream_send(ws->tcp_stream, payload, on_done, userdata);
+			NULL, NULL);
+	return stream_tcp_send(&ws->base, payload, on_done, userdata);
 }
 
 static struct rcbuf* stream_ws_chained_exec(struct stream* tcp_stream,
 		void* userdata)
 {
+	struct stream_ws* ws = (struct stream_ws*)tcp_stream;
 	struct stream_ws_exec_ctx* ctx = userdata;
-	struct stream_ws* ws = tcp_stream->userdata;
 
 	struct rcbuf* buf = ctx->exec(&ws->base, ctx->userdata);
 
+	// TODO: This also needs to be cleaned it it's left on the send queue
+	// when the stream is destroyed.
+	free(ctx->userdata);
+
 	struct vec out;
 	vec_init(&out, WS_HEADER_MIN_SIZE + buf->size + 1);
 
@@ -279,6 +272,7 @@ static struct rcbuf* stream_ws_chained_exec(struct stream* tcp_stream,
 	out.len += head_len;
 
 	vec_append(&out, buf->payload, buf->size);
+	rcbuf_unref(buf);
 	return rcbuf_new(out.data, out.len);
 }
 
@@ -293,23 +287,12 @@ static void stream_ws_exec_and_send(struct stream* self, stream_exec_fn exec,
 	ctx->exec = exec;
 	ctx->userdata = userdata;
 
-	stream_exec_and_send(ws->tcp_stream, stream_ws_chained_exec, ctx);
+	stream_tcp_exec_and_send(&ws->base, stream_ws_chained_exec, ctx);
-}
-
-static void stream_ws_event(struct stream* self, enum stream_event event)
-{
-	struct stream_ws* ws = self->userdata;
-
-	if (event == STREAM_EVENT_REMOTE_CLOSED) {
-		ws->base.state = STREAM_STATE_CLOSED;
-	}
-
-	ws->base.on_event(&ws->base, event);
 }
 
 static struct stream_impl impl = {
-	.close = stream_ws_close,
+	.close = stream_tcp_close,
-	.destroy = stream_ws_destroy,
+	.destroy = stream_tcp_destroy,
 	.read = stream_ws_read,
 	.send = stream_ws_send,
 	.exec_and_send = stream_ws_exec_and_send,
@@ -321,19 +304,11 @@ struct stream* stream_ws_new(int fd, stream_event_fn on_event, void* userdata)
 	if (!self)
 		return NULL;
 
-	self->base.state = STREAM_STATE_NORMAL;
+	stream_tcp_init(&self->base, fd, on_event, userdata);
 	self->base.impl =  &impl;
-	self->base.on_event = on_event;
-	self->base.userdata = userdata;
-
-	self->tcp_stream = stream_new(fd, stream_ws_event, self);
-	if (!self->tcp_stream) {
-		free(self);
-		return NULL;
-	}
 
 	// Don't send anything until handshake is done:
-	self->tcp_stream->cork = true;
+	self->base.cork = true;
 
 	return &self->base;
 }

src/ws-handshake.c

@@ -1,8 +1,7 @@
 #include "websocket.h"
 #include "http.h"
-
+#include "crypto.h"
-#include <nettle/sha1.h>
+#include "base64.h"
-#include <nettle/base64.h>
 
 #include <stdint.h>
 #include <stdio.h>
@@ -61,16 +60,16 @@ ssize_t ws_handshake(char* output, size_t output_maxlen, const char* input)
 	if (have_versions && !strstr(versions, ",13,"))
 		goto failure;
 
-	struct sha1_ctx ctx;
+	uint8_t hash[20];
-	sha1_init(&ctx);
+	crypto_hash_many(hash, sizeof(hash), CRYPTO_HASH_SHA1,
-	sha1_update(&ctx, strlen(challenge), (const uint8_t*)challenge);
+			(struct crypto_data_entry[]){
-	sha1_update(&ctx, strlen(magic_uuid), (const uint8_t*)magic_uuid);
+		{ (uint8_t*)challenge, strlen(challenge) },
+		{ (uint8_t*)magic_uuid, strlen(magic_uuid) },
+		{}
+	});
 
-	uint8_t hash[SHA1_DIGEST_SIZE];
+	char response[BASE64_ENCODED_SIZE(sizeof(hash))] = {};
-	sha1_digest(&ctx, sizeof(hash), hash);
+	base64_encode(response, hash, sizeof(hash));
-
-	char response[BASE64_ENCODE_RAW_LENGTH(SHA1_DIGEST_SIZE) + 1] = {};
-	base64_encode_raw(response, SHA1_DIGEST_SIZE, hash);
 
 	size_t len = snprintf(output, output_maxlen,
 		"HTTP/1.1 101 Switching Protocols\r\n"

test/meson.build

@@ -10,3 +10,12 @@ pixels = executable('pixels',
 	],
 )
 test('pixels', pixels)
+
+base64 = executable('base64',
+	[
+		'test-base64.c',
+		'../src/base64.c',
+	],
+	include_directories: inc,
+)
+test('base64', base64)

test/test-base64.c

@@ -0,0 +1,129 @@
+#include "base64.h"
+
+#include <stdio.h>
+#include <stdbool.h>
+#include <string.h>
+
+static bool test_encode_0(void)
+{
+	char buf[1] = {};
+	base64_encode(buf, (const uint8_t*)"", 0);
+	return strlen(buf) == 0;
+}
+
+static bool test_encode_1(void)
+{
+	static const char input[] = "a";
+	char buf[BASE64_ENCODED_SIZE(sizeof(input) - 1)] = {};
+	base64_encode(buf, (const uint8_t*)input, sizeof(input) - 1);
+	return strcmp(buf, "YQ==") == 0;
+}
+
+static bool test_encode_2(void)
+{
+	static const char input[] = "ab";
+	char buf[BASE64_ENCODED_SIZE(sizeof(input) - 1)] = {};
+	base64_encode(buf, (const uint8_t*)input, sizeof(input) - 1);
+	return strcmp(buf, "YWI=") == 0;
+}
+
+static bool test_encode_3(void)
+{
+	static const char input[] = "abc";
+	char buf[BASE64_ENCODED_SIZE(sizeof(input) - 1)] = {};
+	base64_encode(buf, (const uint8_t*)input, sizeof(input) - 1);
+	return strcmp(buf, "YWJj") == 0;
+}
+
+static bool test_encode_4(void)
+{
+	static const char input[] = "abcd";
+	char buf[BASE64_ENCODED_SIZE(sizeof(input) - 1)] = {};
+	base64_encode(buf, (const uint8_t*)input, sizeof(input) - 1);
+	return strcmp(buf, "YWJjZA==") == 0;
+}
+
+static bool test_encode_5(void)
+{
+	static const char input[] = "abcde";
+	char buf[BASE64_ENCODED_SIZE(sizeof(input) - 1)] = {};
+	base64_encode(buf, (const uint8_t*)input, sizeof(input) - 1);
+	return strcmp(buf, "YWJjZGU=") == 0;
+}
+
+static bool test_decode_0(void)
+{
+	uint8_t buf[1] = {};
+	ssize_t r = base64_decode(buf, "");
+	return r == 0 && buf[0] == 0;
+}
+
+static bool test_decode_1(void)
+{
+	static const char input[] = "YQ==";
+	uint8_t buf[BASE64_DECODED_MAX_SIZE(sizeof(input) - 1)] = {};
+	ssize_t r = base64_decode(buf, input);
+	return r == 1 && memcmp(buf, "a", r) == 0;
+}
+
+static bool test_decode_2(void)
+{
+	static const char input[] = "YWI=";
+	uint8_t buf[BASE64_DECODED_MAX_SIZE(sizeof(input) - 1)] = {};
+	ssize_t r = base64_decode(buf, input);
+	return r == 2 && memcmp(buf, "ab", r) == 0;
+}
+
+static bool test_decode_3(void)
+{
+	static const char input[] = "YWJj";
+	uint8_t buf[BASE64_DECODED_MAX_SIZE(sizeof(input) - 1)] = {};
+	ssize_t r = base64_decode(buf, input);
+	return r == 3 && memcmp(buf, "abc", r) == 0;
+}
+
+static bool test_decode_4(void)
+{
+	static const char input[] = "YWJjZA==";
+	uint8_t buf[BASE64_DECODED_MAX_SIZE(sizeof(input) - 1)] = {};
+	ssize_t r = base64_decode(buf, input);
+	return r == 4 && memcmp(buf, "abcd", r) == 0;
+}
+
+static bool test_decode_5(void)
+{
+	static const char input[] = "YWJjZGU=";
+	uint8_t buf[BASE64_DECODED_MAX_SIZE(sizeof(input) - 1)] = {};
+	ssize_t r = base64_decode(buf, input);
+	return r == 5 && memcmp(buf, "abcde", r) == 0;
+}
+
+#define XSTR(s) STR(s)
+#define STR(s) #s
+
+#define RUN_TEST(name) ({ \
+	bool ok = test_ ## name(); \
+	printf("[%s] %s\n", ok ? " OK " : "FAIL", XSTR(name)); \
+	ok; \
+})
+
+int main()
+{
+	bool ok = true;
+
+	ok &= RUN_TEST(encode_0);
+	ok &= RUN_TEST(encode_1);
+	ok &= RUN_TEST(encode_2);
+	ok &= RUN_TEST(encode_3);
+	ok &= RUN_TEST(encode_4);
+	ok &= RUN_TEST(encode_5);
+
+	ok &= RUN_TEST(decode_0);
+	ok &= RUN_TEST(decode_1);
+	ok &= RUN_TEST(decode_2);
+	ok &= RUN_TEST(decode_3);
+	ok &= RUN_TEST(decode_4);
+	ok &= RUN_TEST(decode_5);
+
+	return ok ? 0 : 1;
+}