checkpoint

1 files changed, 144 insertions, 0 deletions

diff --git a/ws/libs/wsServer/src/handshake.c b/ws/libs/wsServer/src/handshake.c
new file mode 100644
index 0000000..4b8ac30
--- /dev/null
+++ b/ws/libs/wsServer/src/handshake.c
@@ -0,0 +1,144 @@
+/*
+ * Copyright (C) 2016-2024  Davidson Francis <davidsondfgl@gmail.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ */
+#define _POSIX_C_SOURCE 200809L
+#include <base64.h>
+#include <sha1.h>
+#include <ws.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+
+/**
+ * @dir src/
+ * @brief Handshake routines directory
+ *
+ * @file handshake.c
+ * @brief Handshake routines.
+ */
+
+/**
+ * @brief Gets the field Sec-WebSocket-Accept on response, by
+ * an previously informed key.
+ *
+ * @param wsKey Sec-WebSocket-Key
+ * @param dest source to be stored the value.
+ *
+ * @return Returns 0 if success and a negative number
+ * otherwise.
+ *
+ * @attention This is part of the internal API and is documented just
+ * for completeness.
+ */
+int get_handshake_accept(char *wsKey, unsigned char **dest)
+{
+	unsigned char hash[SHA1HashSize]; /* SHA-1 Hash.                   */
+	SHA1Context ctx;                  /* SHA-1 Context.                */
+	char *str;                        /* WebSocket key + magic string. */
+
+	/* Invalid key. */
+	if (!wsKey)
+		return (-1);
+
+	str = calloc(1, sizeof(char) * (WS_KEY_LEN + WS_MS_LEN + 1));
+	if (!str)
+		return (-1);
+
+	strncpy(str, wsKey, WS_KEY_LEN);
+	strcat(str, MAGIC_STRING);
+
+	SHA1Reset(&ctx);
+	SHA1Input(&ctx, (const uint8_t *)str, WS_KEYMS_LEN);
+	SHA1Result(&ctx, hash);
+
+	*dest = base64_encode(hash, SHA1HashSize, NULL);
+	*(*dest + strlen((const char *)*dest) - 1) = '\0';
+	free(str);
+	return (0);
+}
+
+/**
+ * @brief Finds the ocorrence of @p needle in @p haystack, case
+ * insensitive.
+ *
+ * @param haystack Target string to be searched.
+ * @param needle   Substring to search for.
+ *
+ * @returns If found, returns a pointer at the beginning of the
+ * found substring. Otherwise, returns NULL.
+ */
+static char *strstricase(const char *haystack, const char *needle)
+{
+	size_t length;
+	for (length = strlen(needle); *haystack; haystack++)
+		if (!strncasecmp(haystack, needle, length))
+			return (char*)haystack;
+	return (NULL);
+}
+
+/**
+ * @brief Gets the complete response to accomplish a succesfully
+ * handshake.
+ *
+ * @param hsrequest  Client request.
+ * @param hsresponse Server response.
+ *
+ * @return Returns 0 if success and a negative number
+ * otherwise.
+ *
+ * @attention This is part of the internal API and is documented just
+ * for completeness.
+ */
+int get_handshake_response(char *hsrequest, char **hsresponse)
+{
+	unsigned char *accept; /* Accept message.     */
+	char *saveptr;         /* strtok_r() pointer. */
+	char *s;               /* Current string.     */
+	int ret;               /* Return value.       */
+
+	saveptr = NULL;
+	for (s = strtok_r(hsrequest, "\r\n", &saveptr); s != NULL;
+		 s = strtok_r(NULL, "\r\n", &saveptr))
+	{
+		if (strstricase(s, WS_HS_REQ) != NULL)
+			break;
+	}
+
+	/* Ensure that we have a valid pointer. */
+	if (s == NULL)
+		return (-1);
+
+	saveptr = NULL;
+	s       = strtok_r(s, " ", &saveptr);
+	s       = strtok_r(NULL, " ", &saveptr);
+
+	ret = get_handshake_accept(s, &accept);
+	if (ret < 0)
+		return (ret);
+
+	*hsresponse = malloc(sizeof(char) * WS_HS_ACCLEN);
+	if (*hsresponse == NULL)
+		return (-1);
+
+	strcpy(*hsresponse, WS_HS_ACCEPT);
+	strcat(*hsresponse, (const char *)accept);
+	strcat(*hsresponse, "\r\n\r\n");
+
+	free(accept);
+	return (0);
+}