add the 'ead' package (emergency access daemon),

which can provide remote access to your device, even if the ip
and firewall settings are broken

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@13738 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 235 insertions, 0 deletions

diff --git a/package/ead/src/tinysrp/tinysrp.c b/package/ead/src/tinysrp/tinysrp.c
new file mode 100644
index 0000000000..fc01055417
--- /dev/null
+++ b/package/ead/src/tinysrp/tinysrp.c
@@ -0,0 +1,235 @@
+/* This bit implements a simple API for using the SRP library over sockets. */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include "t_defines.h"
+#include "t_pwd.h"
+#include "t_server.h"
+#include "t_client.h"
+#include "tinysrp.h"
+
+#ifndef MSG_WAITALL
+#ifdef linux
+#define MSG_WAITALL 0x100       /* somehow not defined on my box */
+#endif
+#endif
+
+/* This is called by the client with a connected socket, username, and
+passphrase.  pass can be NULL in which case the user is queried. */
+
+int tsrp_client_authenticate(int s, char *user, char *pass, TSRP_SESSION *tsrp)
+{
+	int i, index;
+	unsigned char username[MAXUSERLEN + 1], sbuf[MAXSALTLEN];
+	unsigned char msgbuf[MAXPARAMLEN + 1], bbuf[MAXPARAMLEN];
+	unsigned char passbuf[128], *skey;
+	struct t_client *tc;
+	struct t_preconf *tcp;          /* @@@ should go away */
+	struct t_num salt, *A, B;
+
+	/* Send the username. */
+
+	i = strlen(user);
+	if (i > MAXUSERLEN) {
+		i = MAXUSERLEN;
+	}
+	msgbuf[0] = i;
+	memcpy(msgbuf + 1, user, i);
+	if (send(s, msgbuf, i + 1, 0) < 0) {
+		return 0;
+	}
+	memcpy(username, user, i);
+	username[i] = '\0';
+
+	/* Get the prime index and salt. */
+
+	i = recv(s, msgbuf, 2, MSG_WAITALL);
+	if (i <= 0) {
+		return 0;
+	}
+	index = msgbuf[0];
+	if (index <= 0 || index > t_getprecount()) {
+		return 0;
+	}
+	tcp = t_getpreparam(index - 1);
+	salt.len = msgbuf[1];
+	if (salt.len > MAXSALTLEN) {
+		return 0;
+	}
+	salt.data = sbuf;
+	i = recv(s, sbuf, salt.len, MSG_WAITALL);
+	if (i <= 0) {
+		return 0;
+	}
+
+	/* @@@ t_clientopen() needs a variant that takes the index */
+
+	tc = t_clientopen(username, &tcp->modulus, &tcp->generator, &salt);
+	if (tc == NULL) {
+		return 0;
+	}
+
+	/* Calculate A and send it to the server. */
+
+	A = t_clientgenexp(tc);
+	msgbuf[0] = A->len - 1;         /* len is max 256 */
+	memcpy(msgbuf + 1, A->data, A->len);
+	if (send(s, msgbuf, A->len + 1, 0) < 0) {
+		return 0;
+	}
+
+	/* Ask the user for the passphrase. */
+
+	if (pass == NULL) {
+		t_getpass(passbuf, sizeof(passbuf), "Enter password:");
+		pass = passbuf;
+	}
+	t_clientpasswd(tc, pass);
+
+	/* Get B from the server. */
+
+	i = recv(s, msgbuf, 1, 0);
+	if (i <= 0) {
+		return 0;
+	}
+	B.len = msgbuf[0] + 1;
+	B.data = bbuf;
+	i = recv(s, bbuf, B.len, MSG_WAITALL);
+	if (i <= 0) {
+		return 0;
+	}
+
+	/* Compute the session key. */
+
+	skey = t_clientgetkey(tc, &B);
+	if (skey == NULL) {
+		return 0;
+	}
+
+	/* Send the response. */
+
+	if (send(s, t_clientresponse(tc), RESPONSE_LEN, 0) < 0) {
+		return 0;
+	}
+
+	/* Get the server's response. */
+
+	i = recv(s, msgbuf, RESPONSE_LEN, MSG_WAITALL);
+	if (i <= 0) {
+		return 0;
+	}
+	if (t_clientverify(tc, msgbuf) != 0) {
+		return 0;
+	}
+
+	/* All done.  Now copy the key and clean up. */
+
+	if (tsrp) {
+		memcpy(tsrp->username, username, strlen(username) + 1);
+		memcpy(tsrp->key, skey, SESSION_KEY_LEN);
+	}
+	t_clientclose(tc);
+
+	return 1;
+}
+
+/* This is called by the server with a connected socket. */
+
+int tsrp_server_authenticate(int s, TSRP_SESSION *tsrp)
+{
+	int i, j;
+	unsigned char username[MAXUSERLEN], *skey;
+	unsigned char msgbuf[MAXPARAMLEN + 1], abuf[MAXPARAMLEN];
+	struct t_server *ts;
+	struct t_num A, *B;
+
+	/* Get the username. */
+
+	i = recv(s, msgbuf, 1, 0);
+	if (i <= 0) {
+		return 0;
+	}
+	j = msgbuf[0];
+	i = recv(s, username, j, MSG_WAITALL);
+	if (i <= 0) {
+		return 0;
+	}
+	username[j] = '\0';
+
+	ts = t_serveropen(username);
+	if (ts == NULL) {
+		return 0;
+	}
+
+	/* Send the prime index and the salt. */
+
+	msgbuf[0] = ts->index;                  /* max 256 primes... */
+	i = ts->s.len;
+	msgbuf[1] = i;
+	memcpy(msgbuf + 2, ts->s.data, i);
+	if (send(s, msgbuf, i + 2, 0) < 0) {
+		return 0;
+	}
+
+	/* Calculate B while we're waiting. */
+
+	B = t_servergenexp(ts);
+
+	/* Get A from the client. */
+
+	i = recv(s, msgbuf, 1, 0);
+	if (i <= 0) {
+		return 0;
+	}
+	A.len = msgbuf[0] + 1;
+	A.data = abuf;
+	i = recv(s, abuf, A.len, MSG_WAITALL);
+	if (i <= 0) {
+		return 0;
+	}
+
+	/* Now send B. */
+
+	msgbuf[0] = B->len - 1;
+	memcpy(msgbuf + 1, B->data, B->len);
+	if (send(s, msgbuf, B->len + 1, 0) < 0) {
+		return 0;
+	}
+
+	/* Calculate the session key while we're waiting. */
+
+	skey = t_servergetkey(ts, &A);
+	if (skey == NULL) {
+		return 0;
+	}
+
+	/* Get the response from the client. */
+
+	i = recv(s, msgbuf, RESPONSE_LEN, MSG_WAITALL);
+	if (i <= 0) {
+		return 0;
+	}
+	if (t_serververify(ts, msgbuf) != 0) {
+		return 0;
+	}
+
+	/* Client authenticated.  Now authenticate ourselves to the client. */
+
+	if (send(s, t_serverresponse(ts), RESPONSE_LEN, 0) < 0) {
+		return 0;
+	}
+
+	/* Copy the key and clean up. */
+
+	if (tsrp) {
+		memcpy(tsrp->username, username, strlen(username) + 1);
+		memcpy(tsrp->key, skey, SESSION_KEY_LEN);
+	}
+	t_serverclose(ts);
+
+	return 1;
+}