CHANGELOG.md

@@ -5,6 +5,20 @@ Cytoplasm. It is intended to be updated with every commit that makes a user-faci
 change worth reporting in the change log. As such, it changes frequently between
 releases. Final change log entries are published as [Releases](releases).
 
+## v0.5.0
+
+**TO BE WRITTEN**
+
+### Breaking Changes
+- `ShaToHex` now requires what hash was used.
+
+### New Features
+- LMDB support is available with the `--with-lmdb` flag.
+- MbedTLS summort is available with the `--with-mbed` flag. Please note that Cytoplasm 
+programs using it must be used with the `CYTO_TLS_CA` environment defined to map to a 
+valid CA file, and that the `CYTO_TLS_SEED` flag can be set to use a seedfile, increasing 
+entropy on systems where it is unavailable.
+
 ## v0.4.1
 
 Cytoplasm is now a C99 library! Upgrading from C89 to C99 makes Cytoplasm more portable

README.md

@@ -21,6 +21,7 @@ Cytoplasm aims to have zero software dependencies beyond what is mandated by POS
 
 - OpenSSL
 - LibreSSL
+- MbedTLS (requires the `CYTO_TLS_CA` environment variables for programs built with it)
 
 If TLS support is not enabled, all APIs that use it should fall back to non-TLS behavior in a sensible manner. For example, if TLS support is not enabled, then the HTTP client API will simply return an error if a TLS connection is requested.
 
@@ -50,7 +51,7 @@ You can also run `make install` as `root` to install Cytoplasm to the system. Th
 
 The `configure` script has a number of optional flags, which are as follows:
 
-- `--with-(openssl|libressl)`: Select the TLS implementation to use. OpenSSL is selected by default.
+- `--with-(openssl|libressl|mbed)`: Select the TLS implementation to use. OpenSSL is selected by default.
 - `--disable-tls`: Disable TLS altogether.
 - `--prefix=<path>`: Set the install prefix to set by default in the `Makefile`. This defaults to `/usr/local`, which should be appropriate for most Unix-like systems.
 - `--(enable|disable)-debug`: Control whether or not to enable debug mode. This sets the optimization level to 0 and builds with debug symbols. Useful for running with a debugger.

configure

@@ -76,6 +76,10 @@ for arg in $SCRIPT_ARGS; do
             TLS_IMPL="TLS_LIBRESSL"
             TLS_LIBS="-ltls -lcrypto -lssl"
             ;;
+        --with-mbed)
+            TLS_IMPL="TLS_MBEDTLS"
+            TLS_LIBS="-lmbedtls -lmbedx509 -lmbedcrypto"
+            ;;
         --disable-tls)
             TLS_IMPL=""
             TLS_LIBS=""

include/Cytoplasm/Tls.h

@@ -50,6 +50,7 @@
 
 #define TLS_LIBRESSL 2
 #define TLS_OPENSSL 3
+#define TLS_MBEDTLS 4
 
 /**
  * Create a new TLS client stream using the given file descriptor and

src/Sha/Sha1.c

@@ -29,6 +29,7 @@
 #include <limits.h>
 
 /* TODO: Verify LibreSSL support later */
+#include <Tls.h>
 #if defined(TLS_IMPL) && (TLS_IMPL == TLS_OPENSSL)
 
 #include <openssl/sha.h>

src/Sha/Sha256.c

@@ -31,6 +31,7 @@
 
 
 /* TODO: Verify LibreSSL support later */
+#include <Tls.h>
 #if defined(TLS_IMPL) && (TLS_IMPL == TLS_OPENSSL)
 
 #include <openssl/sha.h>

src/Tls/TlsMbedTLS.c

@@ -0,0 +1,414 @@
+/*
+ * Copyright (C) 2022-2024 Jordan Bancino <@jordan:bancino.net> with
+ * other valuable contributors. See CONTRIBUTORS.txt for the full list.
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#include <Tls.h>
+
+#if TLS_IMPL == TLS_MBEDTLS
+
+#include "mbedtls/net_sockets.h"
+#include "mbedtls/ssl.h"
+#include "mbedtls/entropy.h"
+#include "mbedtls/ctr_drbg.h"
+#include "mbedtls/debug.h"
+#include "mbedtls/error.h"
+
+#include <Memory.h>
+#include <Log.h>
+#include <Str.h>
+
+#include <string.h>
+#include <stdlib.h>
+
+/*
+ * #include statements and any implementation structures
+ * needed should go here.
+ */
+typedef struct MbedCookie {
+    int fd;
+    bool serverside;
+
+    mbedtls_net_context serverFD;
+    mbedtls_entropy_context entropy;
+    mbedtls_ctr_drbg_context ctrDrbg;
+    mbedtls_ssl_context ssl;
+    mbedtls_ssl_config conf;
+    mbedtls_x509_crt cert;
+
+    mbedtls_pk_context serverkey;
+} MbedCookie;
+
+static bool
+AddPEM(mbedtls_x509_crt *certs, char *path)
+{
+    size_t len;
+    if (!certs || !path)
+    {
+        return false;
+    }
+
+    len = strlen(path);
+    if (len >= 4 && StrEquals(&path[len - 1 - 4], ".pem"))
+    {
+        /* Parse it as a file */
+        if (mbedtls_x509_crt_parse_file(certs, path) == 0)
+        {
+            return true;
+        }
+    }
+
+    /* Parse it as a directory if it is not a .PEM 
+     * Note that this is non-recursive. */
+    return mbedtls_x509_crt_parse_path(certs, path) == 0;
+}
+static bool
+RegisterPEMs(mbedtls_x509_crt *certs)
+{
+    char *cafile;
+    if (!certs)
+    {
+        return false;
+    }
+
+    /* Step 0: Load from CYTO_TLS_CA if present to overwrite */
+    cafile = getenv("CYTO_TLS_CA");
+    if (AddPEM(certs, cafile))
+    {
+        return true;
+    }
+
+    /* Step 1: Try /etc/ssl/certs */
+    if (AddPEM(certs, "/etc/ssl/certs"))
+    {
+        return true;
+    }
+    /* Step 2: Try loading off Mozilla's certificates */
+    if (AddPEM(certs, "/usr/share/ca-certificates/mozilla"))
+    {
+        return true;
+    }
+
+    /* Step 3: Try loading from its root directly*/
+    if (AddPEM(certs, "/usr/share/ca-certificates"))
+    {
+        return true;
+    }
+
+    /* Step 4: Give up. */
+    return false;
+}
+
+void *
+TlsInitClient(int fd, const char *serverName)
+{
+    MbedCookie *cookie;
+    int err;
+    if (!serverName)
+    {
+        return NULL;
+    }
+
+    cookie = Malloc(sizeof(MbedCookie));
+    memset(cookie, 0, sizeof(MbedCookie));
+    cookie->fd = fd;
+    cookie->serverside = false;
+
+    /* Initialise MbedTLS */
+    mbedtls_net_init(&cookie->serverFD);
+    mbedtls_ssl_init(&cookie->ssl);
+    mbedtls_ssl_config_init(&cookie->conf);
+    mbedtls_x509_crt_init(&cookie->cert);
+    mbedtls_ctr_drbg_init(&cookie->ctrDrbg);
+    mbedtls_pk_init(&cookie->serverkey);
+
+    mbedtls_entropy_init(&cookie->entropy);
+    err = mbedtls_ctr_drbg_seed(
+        &cookie->ctrDrbg, 
+        mbedtls_entropy_func, 
+        &cookie->entropy,
+        (const unsigned char *) serverName, strlen(serverName)
+    );
+    if (err != 0)
+    {
+        Log(LOG_ERR, "MbedTLS failure on client init: %d", err);
+        goto error;
+    }
+
+    /* TODO: Reconsider a source of additional entropy. */
+
+    cookie->serverFD.fd = fd;
+
+    err = mbedtls_ssl_config_defaults(
+        &cookie->conf,
+        MBEDTLS_SSL_IS_CLIENT,
+        MBEDTLS_SSL_TRANSPORT_STREAM,
+        MBEDTLS_SSL_PRESET_DEFAULT
+    );
+    if (err != 0)
+    {
+        char message[256];
+        mbedtls_strerror(err, message, 255);
+        Log(LOG_ERR, "MbedTLS failure on client certs: %s", message);
+        goto error;
+    }
+
+    /* Setup key verification */
+    if (!RegisterPEMs(&cookie->cert))
+    {
+        char message[256];
+        mbedtls_strerror(err, message, 255);
+        Log(LOG_ERR, "MbedTLS failure on client certs: %s", message);
+        goto error;
+    }
+    mbedtls_ssl_conf_ca_chain(&cookie->conf, &cookie->cert, NULL);
+
+    /* Setup some callbacks */
+    mbedtls_ssl_conf_rng(
+        &cookie->conf, 
+        mbedtls_ctr_drbg_random, 
+        &cookie->ctrDrbg
+    );
+    if ((err = mbedtls_ssl_setup(&cookie->ssl, &cookie->conf)) != 0)
+    {
+        char message[256];
+        mbedtls_strerror(err, message, 255);
+        Log(LOG_ERR, "MbedTLS failure on SSL setup: %s", message);
+        goto error;
+    }
+
+    /* Setup the servername */
+    if ((err = mbedtls_ssl_set_hostname(&cookie->ssl, serverName)) != 0)
+    {
+        char message[256];
+        mbedtls_strerror(err, message, 255);
+        Log(LOG_ERR, "MbedTLS failure on client hostname: %s", message);
+        goto error;
+    }
+
+    /* Setup some functions */
+    mbedtls_ssl_set_bio(
+        &cookie->ssl, &cookie->serverFD,
+        mbedtls_net_send, mbedtls_net_recv, NULL
+    );
+    return cookie;
+error:
+
+    mbedtls_net_free(&cookie->serverFD);
+    mbedtls_ssl_free(&cookie->ssl);
+    mbedtls_ssl_config_free(&cookie->conf);
+    mbedtls_ctr_drbg_free(&cookie->ctrDrbg);
+    mbedtls_entropy_free(&cookie->entropy);
+    Free(cookie);
+    return NULL;
+}
+
+void *
+TlsInitServer(int fd, const char *crt, const char *key)
+{
+    MbedCookie *cookie;
+    char *seed;
+    int err;
+    if (!crt || !key)
+    {
+        return NULL;
+    }
+
+    cookie = Malloc(sizeof(MbedCookie));
+    memset(cookie, 0, sizeof(MbedCookie));
+    cookie->fd = fd;
+    cookie->serverside = true;
+
+    /* Initialise MbedTLS */
+    mbedtls_net_init(&cookie->serverFD);
+    mbedtls_ssl_init(&cookie->ssl);
+    mbedtls_ssl_config_init(&cookie->conf);
+    mbedtls_x509_crt_init(&cookie->cert);
+    mbedtls_ctr_drbg_init(&cookie->ctrDrbg);
+    mbedtls_pk_init(&cookie->serverkey);
+
+    mbedtls_entropy_init(&cookie->entropy);
+    err = mbedtls_ctr_drbg_seed(
+        &cookie->ctrDrbg, 
+        mbedtls_entropy_func, 
+        &cookie->entropy,
+        (const unsigned char *) key, strlen(key)
+    );
+    if (err != 0)
+    {
+        Log(LOG_ERR, "MbedTLS failure on server init: %d", err);
+        goto error;
+    }
+    /* Add a source of entropy if possible(using the CYTO_TLS_SEED env).
+     * Note that we ignore the error code. */
+    seed = getenv("CYTO_TLS_SEED");
+    mbedtls_entropy_update_seed_file(&cookie->entropy, seed);
+
+    /* Setup key verification */
+    if ((err = mbedtls_x509_crt_parse_file(&cookie->cert, crt)) != 0)
+    {
+        char message[256];
+        mbedtls_strerror(err, message, 255);
+        Log(LOG_ERR, "MbedTLS failure on server certs: %s", message);
+        goto error;
+    }
+
+         
+         
+    if ((err = mbedtls_pk_parse_keyfile(&cookie->serverkey, key, NULL, mbedtls_entropy_func, &cookie->ctrDrbg)) != 0)
+    {
+        char message[256];
+        mbedtls_strerror(err, message, 255);
+        Log(LOG_ERR, "MbedTLS failure on server certs: %s", message);
+        goto error;
+    }
+    mbedtls_ssl_conf_ca_chain(&cookie->conf, cookie->cert.next, NULL);
+    if ((err = mbedtls_ssl_conf_own_cert(&cookie->conf, &cookie->cert, &cookie->serverkey)) != 0)
+    {
+        char message[256];
+        mbedtls_strerror(err, message, 255);
+        Log(LOG_ERR, "MbedTLS failure on server certs: %s", message);
+        goto error;
+    }
+
+    /* Setup SSL */
+    cookie->serverFD.fd = fd;
+    err = mbedtls_ssl_config_defaults(
+        &cookie->conf,
+        MBEDTLS_SSL_IS_SERVER,
+        MBEDTLS_SSL_TRANSPORT_STREAM,
+        MBEDTLS_SSL_PRESET_DEFAULT
+    );
+    if (err != 0)
+    {
+        char message[256];
+        mbedtls_strerror(err, message, 255);
+        Log(LOG_ERR, "MbedTLS failure on server SSL: %s", message);
+        goto error;
+    }
+
+    /* Setup some callbacks */
+    mbedtls_ssl_conf_rng(
+        &cookie->conf, 
+        mbedtls_ctr_drbg_random, 
+        &cookie->ctrDrbg
+    );
+    mbedtls_ssl_conf_ca_chain(&cookie->conf, cookie->cert.next, NULL);
+    if ((err = mbedtls_ssl_setup(&cookie->ssl, &cookie->conf)) != 0)
+    {
+        char message[256];
+        mbedtls_strerror(err, message, 255);
+        Log(LOG_ERR, "MbedTLS failure on SSL setup: %s", message);
+        goto error;
+    }
+
+    /* Client connexion */
+    /* Setup some functions */
+    mbedtls_ssl_set_bio(
+        &cookie->ssl, &cookie->serverFD,
+        mbedtls_net_send, mbedtls_net_recv, NULL
+    );
+
+    /* Handshake the client */
+    while ((err = mbedtls_ssl_handshake(&cookie->ssl)) != 0) 
+    {
+        switch (err)
+        {
+            case MBEDTLS_ERR_SSL_WANT_WRITE:
+            case MBEDTLS_ERR_SSL_WANT_READ:
+                break;
+            default:
+                goto error;
+        }
+    }
+    return cookie;
+error:
+
+    mbedtls_net_free(&cookie->serverFD);
+    mbedtls_ssl_free(&cookie->ssl);
+    mbedtls_ssl_config_free(&cookie->conf);
+    mbedtls_ctr_drbg_free(&cookie->ctrDrbg);
+    mbedtls_entropy_free(&cookie->entropy);
+    Free(cookie);
+    return NULL;
+}
+
+ssize_t
+TlsRead(void *cookie, void *buf, size_t nBytes)
+{
+    MbedCookie *cooked = cookie;
+    int ret;
+    if (!cookie || !buf)
+    {
+        return -1;
+    }
+    ret = mbedtls_ssl_read(&cooked->ssl, buf, nBytes);
+    if (ret <= 0)
+    {
+        ret = -1;
+    }
+    return ret;
+}
+
+ssize_t
+TlsWrite(void *cookie, void *buf, size_t nBytes)
+{
+    MbedCookie *cooked = cookie;
+    int ret;
+    if (!cookie || !buf)
+    {
+        return -1;
+    }
+    ret = mbedtls_ssl_write(&cooked->ssl, buf, nBytes);
+    if (ret <= 0)
+    {
+        ret = -1;
+    }
+
+    return ret;
+}
+
+int
+TlsClose(void *cookie)
+{
+    MbedCookie *cooked = cookie;
+    if (!cookie)
+    {
+        return -1;
+    }
+
+    mbedtls_net_free(&cooked->serverFD);
+    mbedtls_ssl_free(&cooked->ssl);
+    mbedtls_ssl_config_free(&cooked->conf);
+    mbedtls_ctr_drbg_free(&cooked->ctrDrbg);
+    mbedtls_entropy_free(&cooked->entropy);
+    mbedtls_x509_crt_free(&cooked->cert);
+
+    if (cooked->serverside)
+    {
+        mbedtls_pk_free(&cooked->serverkey);
+    }
+    Free(cooked);
+    return 0;
+}
+
+#endif