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Diffstat (limited to '')
-rw-r--r-- | src/auths/pwcheck.c | 454 |
1 files changed, 454 insertions, 0 deletions
diff --git a/src/auths/pwcheck.c b/src/auths/pwcheck.c new file mode 100644 index 0000000..f733b98 --- /dev/null +++ b/src/auths/pwcheck.c @@ -0,0 +1,454 @@ +/* SASL server API implementation + * Rob Siemborski + * Tim Martin + * $Id: checkpw.c,v 1.49 2002/03/07 19:14:04 ken3 Exp $ + */ +/* + * Copyright (c) 2001 Carnegie Mellon University. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * 3. The name "Carnegie Mellon University" must not be used to + * endorse or promote products derived from this software without + * prior written permission. For permission or any other legal + * details, please contact + * Office of Technology Transfer + * Carnegie Mellon University + * 5000 Forbes Avenue + * Pittsburgh, PA 15213-3890 + * (412) 268-4387, fax: (412) 268-7395 + * tech-transfer@andrew.cmu.edu + * + * 4. Redistributions of any form whatsoever must retain the following + * acknowledgment: + * "This product includes software developed by Computing Services + * at Carnegie Mellon University (http://www.cmu.edu/computing/)." + * + * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO + * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY + * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE + * FOR ANY SPECIAL, 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. + */ + +/* + * Taken from Cyrus-SASL library and adapted by Alexander S. Sabourenkov + * Oct 2001 - Apr 2002: Slightly modified by Philip Hazel. + * Aug 2003: new code for saslauthd from Alexander S. Sabourenkov incorporated + * by Philip Hazel (minor mods to avoid compiler warnings) + * Oct 2006: (PH) removed redundant tests on "reply" being NULL - some were + * missing, and confused someone who was using this code for some + * other purpose. Here in Exim, "reply" is never NULL. + * + * screwdriver@lxnt.info + * + */ + +/* Originally this module supported only the pwcheck daemon, which is where its +name comes from. Nowadays it supports saslauthd as well; pwcheck is in fact +deprecated. The definitions of CYRUS_PWCHECK_SOCKET and CYRUS_SASLAUTHD_SOCKET +determine whether the facilities are actually supported or not. */ + + +#include "../exim.h" +#include "pwcheck.h" + + +#if defined(CYRUS_PWCHECK_SOCKET) || defined(CYRUS_SASLAUTHD_SOCKET) + +#include <sys/uio.h> + +static int retry_read(int, void *, unsigned ); +static int retry_writev(int, struct iovec *, int ); +static int read_string(int, uschar **); +static int write_string(int, const uschar *, int); + +#endif + + +/* A dummy function that always fails if pwcheck support is not +wanted. */ + +#ifndef CYRUS_PWCHECK_SOCKET +int pwcheck_verify_password(const char *userid, + const char *passwd, + const char **reply) +{ +userid = userid; /* Keep picky compilers happy */ +passwd = passwd; +*reply = "pwcheck support is not included in this Exim binary"; +return PWCHECK_FAIL; +} + + +/* This is the real function */ + +#else + + /* taken from cyrus-sasl file checkpw.c */ + /* pwcheck daemon-authenticated login */ + int pwcheck_verify_password(const char *userid, + const char *passwd, + const char **reply) + { + int s, start, r, n; + struct sockaddr_un srvaddr; + struct iovec iov[2]; + static char response[1024]; + + *reply = NULL; + + s = socket(AF_UNIX, SOCK_STREAM, 0); + if (s == -1) { return PWCHECK_FAIL; } + + memset(CS &srvaddr, 0, sizeof(srvaddr)); + srvaddr.sun_family = AF_UNIX; + strncpy(srvaddr.sun_path, CYRUS_PWCHECK_SOCKET, sizeof(srvaddr.sun_path)); + r = connect(s, (struct sockaddr *)&srvaddr, sizeof(srvaddr)); + if (r == -1) { + DEBUG(D_auth) + debug_printf("Cannot connect to pwcheck daemon (at '%s')\n",CYRUS_PWCHECK_SOCKET); + *reply = "cannot connect to pwcheck daemon"; + return PWCHECK_FAIL; + } + + iov[0].iov_base = CS userid; + iov[0].iov_len = strlen(userid)+1; + iov[1].iov_base = CS passwd; + iov[1].iov_len = strlen(passwd)+1; + + retry_writev(s, iov, 2); + + start = 0; + while (start < sizeof(response) - 1) { + n = read(s, response+start, sizeof(response) - 1 - start); + if (n < 1) break; + start += n; + } + + (void)close(s); + + if (start > 1 && !strncmp(response, "OK", 2)) { + return PWCHECK_OK; + } + + response[start] = '\0'; + *reply = response; + return PWCHECK_NO; + } + +#endif + + + + /* A dummy function that always fails if saslauthd support is not +wanted. */ + +#ifndef CYRUS_SASLAUTHD_SOCKET +int saslauthd_verify_password(const uschar *userid, + const uschar *passwd, + const uschar *service, + const uschar *realm, + const uschar **reply) +{ +userid = userid; /* Keep picky compilers happy */ +passwd = passwd; +service = service; +realm = realm; +*reply = US"saslauthd support is not included in this Exim binary"; +return PWCHECK_FAIL; +} + + +/* This is the real function */ + +#else + /* written from scratch */ + /* saslauthd daemon-authenticated login */ + +int saslauthd_verify_password(const uschar *userid, + const uschar *password, + const uschar *service, + const uschar *realm, + const uschar **reply) +{ + uschar *daemon_reply = NULL; + int s, r; + struct sockaddr_un srvaddr; + + DEBUG(D_auth) + debug_printf("saslauthd userid='%s' servicename='%s'" + " realm='%s'\n", userid, service, realm ); + + *reply = NULL; + + s = socket(AF_UNIX, SOCK_STREAM, 0); + if (s == -1) { + *reply = CUstrerror(errno); + return PWCHECK_FAIL; + } + + memset(CS &srvaddr, 0, sizeof(srvaddr)); + srvaddr.sun_family = AF_UNIX; + strncpy(srvaddr.sun_path, CYRUS_SASLAUTHD_SOCKET, + sizeof(srvaddr.sun_path)); + r = connect(s, (struct sockaddr *)&srvaddr, sizeof(srvaddr)); + if (r == -1) { + DEBUG(D_auth) + debug_printf("Cannot connect to saslauthd daemon (at '%s'): %s\n", + CYRUS_SASLAUTHD_SOCKET, strerror(errno)); + *reply = string_sprintf("cannot connect to saslauthd daemon at " + "%s: %s", CYRUS_SASLAUTHD_SOCKET, + strerror(errno)); + return PWCHECK_FAIL; + } + + if ( write_string(s, userid, Ustrlen(userid)) < 0) { + DEBUG(D_auth) + debug_printf("Failed to send userid to saslauthd daemon \n"); + (void)close(s); + return PWCHECK_FAIL; + } + + if ( write_string(s, password, Ustrlen(password)) < 0) { + DEBUG(D_auth) + debug_printf("Failed to send password to saslauthd daemon \n"); + (void)close(s); + return PWCHECK_FAIL; + } + + memset((void *)password, 0, Ustrlen(password)); + + if ( write_string(s, service, Ustrlen(service)) < 0) { + DEBUG(D_auth) + debug_printf("Failed to send service name to saslauthd daemon \n"); + (void)close(s); + return PWCHECK_FAIL; + } + + if ( write_string(s, realm, Ustrlen(realm)) < 0) { + DEBUG(D_auth) + debug_printf("Failed to send realm to saslauthd daemon \n"); + (void)close(s); + return PWCHECK_FAIL; + } + + if ( read_string(s, &daemon_reply ) < 2) { + DEBUG(D_auth) + debug_printf("Corrupted answer '%s' received. \n", daemon_reply); + (void)close(s); + return PWCHECK_FAIL; + } + + (void)close(s); + + DEBUG(D_auth) + debug_printf("Answer '%s' received. \n", daemon_reply); + + *reply = daemon_reply; + + if ( (daemon_reply[0] == 'O') && (daemon_reply[1] == 'K') ) + return PWCHECK_OK; + + if ( (daemon_reply[0] == 'N') && (daemon_reply[1] == 'O') ) + return PWCHECK_NO; + + return PWCHECK_FAIL; +} + +#endif + + +/* helper functions */ +#if defined(CYRUS_PWCHECK_SOCKET) || defined(CYRUS_SASLAUTHD_SOCKET) + +#define MAX_REQ_LEN 1024 + +/* written from scratch */ + +/* FUNCTION: read_string */ + +/* SYNOPSIS + * read a sasld-style counted string into + * store-allocated buffer, set pointer to the buffer, + * return number of bytes read or -1 on failure. + * END SYNOPSIS */ + +static int read_string(int fd, uschar **retval) { + unsigned short count; + int rc; + + rc = (retry_read(fd, &count, sizeof(count)) < (int) sizeof(count)); + if (!rc) { + count = ntohs(count); + if (count > MAX_REQ_LEN) { + return -1; + } else { + /* Assume the file is trusted, so no tainting */ + *retval = store_get(count + 1, FALSE); + rc = (retry_read(fd, *retval, count) < (int) count); + (*retval)[count] = '\0'; + return count; + } + } + return -1; +} + + +/* FUNCTION: write_string */ + +/* SYNOPSIS + * write a sasld-style counted string into given fd + * written bytes on success, -1 on failure. + * END SYNOPSIS */ + +static int write_string(int fd, const uschar *string, int len) { + unsigned short count; + int rc; + struct iovec iov[2]; + + count = htons(len); + + iov[0].iov_base = (void *) &count; + iov[0].iov_len = sizeof(count); + iov[1].iov_base = (void *) string; + iov[1].iov_len = len; + + rc = retry_writev(fd, iov, 2); + + return rc; +} + + +/* taken from cyrus-sasl file saslauthd/saslauthd-unix.c */ + +/* FUNCTION: retry_read */ + +/* SYNOPSIS + * Keep calling the read() system call with 'fd', 'buf', and 'nbyte' + * until all the data is read in or an error occurs. + * END SYNOPSIS */ +static int retry_read(int fd, void *inbuf, unsigned nbyte) +{ + int n; + int nread = 0; + char *buf = CS inbuf; + + if (nbyte == 0) return 0; + + for (;;) { + n = read(fd, buf, nbyte); + if (n == 0) { + /* end of file */ + return -1; + } + if (n == -1) { + if (errno == EINTR) continue; + return -1; + } + + nread += n; + + if (n >= (int) nbyte) return nread; + + buf += n; + nbyte -= n; + } +} + +/* END FUNCTION: retry_read */ + +/* FUNCTION: retry_writev */ + +/* SYNOPSIS + * Keep calling the writev() system call with 'fd', 'iov', and 'iovcnt' + * until all the data is written out or an error occurs. + * END SYNOPSIS */ + +static int /* R: bytes written, or -1 on error */ +retry_writev ( + /* PARAMETERS */ + int fd, /* I: fd to write on */ + struct iovec *iov, /* U: iovec array base + * modified as data written */ + int iovcnt /* I: number of iovec entries */ + /* END PARAMETERS */ + ) +{ + /* VARIABLES */ + int n; /* return value from writev() */ + int i; /* loop counter */ + int written; /* bytes written so far */ + static int iov_max; /* max number of iovec entries */ + /* END VARIABLES */ + + /* initialization */ +#ifdef MAXIOV + iov_max = MAXIOV; +#else /* ! MAXIOV */ +# ifdef IOV_MAX + iov_max = IOV_MAX; +# else /* ! IOV_MAX */ + iov_max = 8192; +# endif /* ! IOV_MAX */ +#endif /* ! MAXIOV */ + written = 0; + + for (;;) { + + while (iovcnt && iov[0].iov_len == 0) { + iov++; + iovcnt--; + } + + if (!iovcnt) { + return written; + } + + n = writev(fd, iov, iovcnt > iov_max ? iov_max : iovcnt); + if (n == -1) { + if (errno == EINVAL && iov_max > 10) { + iov_max /= 2; + continue; + } + if (errno == EINTR) { + continue; + } + return -1; + } else { + written += n; + } + + for (i = 0; i < iovcnt; i++) { + if (iov[i].iov_len > (unsigned) n) { + iov[i].iov_base = CS iov[i].iov_base + n; + iov[i].iov_len -= n; + break; + } + n -= iov[i].iov_len; + iov[i].iov_len = 0; + } + + if (i == iovcnt) { + return written; + } + } + /* NOTREACHED */ +} + +/* END FUNCTION: retry_writev */ +#endif + +/* End of auths/pwcheck.c */ |