/* support rsync authentication */
#include "rsync.h"
+/***************************************************************************
+encode a buffer using base64 - simple and slow algorithm. null terminates
+the result.
+ ***************************************************************************/
+static void base64_encode(char *buf, int len, char *out)
+{
+ char *b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+ int bit_offset, byte_offset, idx, i;
+ unsigned char *d = (unsigned char *)buf;
+ char *p;
+ int bytes = (len*8 + 5)/6;
+
+ memset(out, 0, bytes+1);
+
+ for (i=0;i<bytes;i++) {
+ byte_offset = (i*6)/8;
+ bit_offset = (i*6)%8;
+ if (bit_offset < 3) {
+ idx = (d[byte_offset] >> (2-bit_offset)) & 0x3F;
+ } else {
+ idx = (d[byte_offset] << (bit_offset-2)) & 0x3F;
+ if (byte_offset+1 < len) {
+ idx |= (d[byte_offset+1] >> (8-(bit_offset-2)));
+ }
+ }
+ out[i] = b64[idx];
+ }
+}
+
+/* create a 16 byte challenge buffer */
+static void gen_challenge(char *addr, char *challenge)
+{
+ char input[32];
+ struct timeval tv;
+
+ memset(input, 0, sizeof(input));
+
+ strncpy((char *)input, addr, 16);
+ gettimeofday(&tv, NULL);
+ SIVAL(input, 16, tv.tv_sec);
+ SIVAL(input, 20, tv.tv_usec);
+ SIVAL(input, 24, getpid());
+
+ sum_init();
+ sum_update(input, sizeof(input));
+ sum_end(challenge);
+}
+
+
+/* return the secret for a user from the sercret file. maximum length
+ is len. null terminate it */
+static int get_secret(int module, char *user, char *secret, int len)
+{
+ char *fname = lp_secrets_file(module);
+ int fd, found=0;
+ char line[1024];
+ char *p, *pass;
+
+ if (!fname || !*fname) return 0;
+
+ fd = open(fname,O_RDONLY);
+ if (fd == -1) return 0;
+
+ while (!found) {
+ int i = 0;
+ memset(line, 0, sizeof(line));
+ while (i<(sizeof(line)-1)) {
+ if (read(fd, &line[i], 1) != 1) {
+ memset(line, 0, sizeof(line));
+ close(fd);
+ return 0;
+ }
+ if (line[i] == '\r') continue;
+ if (line[i] == '\n') break;
+ i++;
+ }
+ line[i] = 0;
+ if (line[0] == '#') continue;
+ p = strchr(line,':');
+ if (!p) continue;
+ *p = 0;
+ if (strcmp(user, line)) continue;
+ pass = p+1;
+ found = 1;
+ }
+
+ close(fd);
+ if (!found) return 0;
+
+ if (strlen(pass) > len-1) {
+ memset(line, 0, sizeof(line));
+ return 0;
+ }
+
+ strcpy(secret, pass);
+ return 1;
+}
+
+/* generate a 16 byte hash from a password and challenge */
+void generate_hash(char *in, char *challenge, char *out)
+{
+ char buf[16];
+
+ sum_init();
+ sum_update(in, strlen(in));
+ sum_update(challenge, strlen(challenge));
+ sum_end(buf);
+
+ base64_encode(buf, 16, out);
+}
+
+/* possible negotiate authentication with the client. Use "leader" to
+ start off the auth if necessary */
+int auth_server(int fd, int module, char *addr, char *leader)
+{
+ char *users = lp_auth_users(module);
+ char challenge[16];
+ char b64_challenge[30];
+ char line[1024];
+ char user[100];
+ char secret[100];
+ char pass[30];
+ char pass2[30];
+
+ /* if no auth list then allow anyone in! */
+ if (!users || !*users) return 1;
+
+ gen_challenge(addr, challenge);
+
+ base64_encode(challenge, 16, b64_challenge);
+
+ io_printf(fd,"%s%s\n", leader, b64_challenge);
+
+ if (!read_line(fd, line, sizeof(line)-1)) {
+ return 0;
+ }
+
+ memset(user, 0, sizeof(user));
+ memset(pass, 0, sizeof(pass));
+
+ if (sscanf(line,"%99s %29s", user, pass) != 2) {
+ return 0;
+ }
+
+ memset(secret, 0, sizeof(secret));
+ if (!get_secret(module, user, secret, sizeof(secret)-1)) {
+ memset(secret, 0, sizeof(secret));
+ return 0;
+ }
+
+ generate_hash(secret, b64_challenge, pass2);
+ memset(secret, 0, sizeof(secret));
+
+ return (strcmp(pass, pass2) == 0);
+}
+
+
+void auth_client(int fd, char *user, char *challenge)
+{
+ char *pass;
+ char pass2[30];
+
+ if (!user || !*user) return;
+
+ if (!(pass=getenv("RSYNC_PASSWORD"))) {
+ pass = getpass("Password: ");
+ }
+
+ if (!pass || !*pass) {
+ pass = "";
+ }
+
+ generate_hash(pass, challenge, pass2);
+
+ io_printf(fd, "%s %s\n", user, pass2);
+}
+
Matt McCutchen's Web Site / rsync / rsync.git / blobdiff