/* ======================================================================== * Copyright 2019-2021 Eduardo Chappa * Copyright 2008-2009 Mark Crispin * ======================================================================== */ /* * Program: SSL authentication/encryption module * * Author: Mark Crispin * * Date: 22 September 1998 * Last Edited: 8 November 2009 * * Previous versions of this file were * * Copyright 1988-2008 University of Washington * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * */ #define crypt ssl_private_crypt #define STRING OPENSSL_STRING #include #include #include #include #include #include #include #include #ifdef OPENSSL_1_1_0 #include #include #endif /* OPENSSL_1_1_0 */ #undef STRING #undef crypt #define SSLBUFLEN 8192 /* * PCI auditing compliance, disable: * SSLv2 * anonymous D-H (no certificate * export encryption ciphers (40 and 56 bits) * low encryption cipher suites (40 and 56 bits, excluding export) * null encryption (disabling implied by "ALL") * * UW imapd just disables low-grade and null ("ALL:!LOW"). This setting * will break clients that attempt to use the newly-prohibited mechanisms. * * I question the value of disabling SSLv2, as opposed to disabling the SSL * ports (e.g., 993 for IMAP, 995 for POP3) and using TLS exclusively. */ #define SSLCIPHERLIST "ALL:!SSLv2:!ADH:!EXP:!LOW" /* SSL I/O stream */ typedef struct ssl_stream { TCPSTREAM *tcpstream; /* TCP stream */ SSL_CTX *context; /* SSL context */ SSL *con; /* SSL connection */ int ictr; /* input counter */ char *iptr; /* input pointer */ char ibuf[SSLBUFLEN]; /* input buffer */ } SSLSTREAM; #include "sslio.h" /* Function prototypes */ long ssl_disable_mask(int ssl_version, int direction); const SSL_METHOD *ssl_connect_mthd(int flag, int *minv, int *maxv); static SSLSTREAM *ssl_start(TCPSTREAM *tstream,char *host,unsigned long flags); static char *ssl_start_work (SSLSTREAM *stream,char *host,unsigned long flags); static int ssl_open_verify (int ok,X509_STORE_CTX *ctx); static char *ssl_validate_cert (X509 *cert,char *host); static long ssl_compare_hostnames (unsigned char *s,unsigned char *pat); static char *ssl_getline_work (SSLSTREAM *stream,unsigned long *size, long *contd); static long ssl_abort (SSLSTREAM *stream); #ifdef OPENSSL_1_1_0 #define SSL_CTX_TYPE SSL_CTX #else #define SSL_CTX_TYPE SSL #endif /* OPENSSL_1_1_0 */ static RSA *ssl_genkey (SSL_CTX_TYPE *con,int export,int keylength); typedef struct ssl_versions_s { char *name; int version; } SSL_VERSIONS_S; int pith_ssl_encryption_version(char *s) { SSL_VERSIONS_S ssl_versions[] = { { "no_min", 0 }, { "ssl3", SSL3_VERSION }, { "tls1", TLS1_VERSION }, { "tls1_1", TLS1_1_VERSION }, { "tls1_2", TLS1_2_VERSION }, #ifdef TLS1_3_VERSION { "tls1_3", TLS1_3_VERSION }, #endif /* TLS1_3_VERSION */ { "no_max", 0 }, /* set this last in the list */ { NULL, 0 }, }; int i; if (s == NULL || *s == '\0') return -1; for (i = 0; ssl_versions[i].name != NULL; i++) if (strcmp(ssl_versions[i].name, s) == 0) break; if (strcmp(s, "no_max") == 0) i--; return ssl_versions[i].name != NULL ? ssl_versions[i].version : -1; } /* Secure Sockets Layer network driver dispatch */ static struct ssl_driver ssldriver = { ssl_open, /* open connection */ ssl_aopen, /* open preauthenticated connection */ ssl_getline, /* get a line */ ssl_getbuffer, /* get a buffer */ ssl_soutr, /* output pushed data */ ssl_sout, /* output string */ ssl_close, /* close connection */ ssl_host, /* return host name */ ssl_remotehost, /* return remote host name */ ssl_port, /* return port number */ ssl_localhost, /* return local host name */ ssl_getsize /* return needed number of bytes */ }; /* non-NIL if doing SSL primary I/O */ static SSLSTDIOSTREAM *sslstdio = NIL; static char *start_tls = NIL; /* non-NIL if start TLS requested */ /* One-time SSL initialization */ static int sslonceonly = 0; void ssl_onceonlyinit (void) { if (!sslonceonly++) { /* only need to call it once */ int fd; char tmp[MAILTMPLEN]; struct stat sbuf; /* if system doesn't have /dev/urandom */ if (stat ("/dev/urandom",&sbuf)) { strcpy(tmp, "SSLXXXXXX"); while ((fd = mkstemp(tmp)) < 0) sleep (1); fstat (fd,&sbuf); /* get information about the file */ close (fd); /* flush descriptor */ unlink (tmp); /* don't need the file */ /* not great but it'll have to do */ sprintf (tmp + strlen (tmp),"%.80s%lx%.80s%lx%lx%lx%lx%lx", tcp_serveraddr (),(unsigned long) tcp_serverport (), tcp_clientaddr (),(unsigned long) tcp_clientport (), (unsigned long) sbuf.st_ino,(unsigned long) time (0), (unsigned long) gethostid (),(unsigned long) getpid ()); RAND_seed (tmp,strlen (tmp)); } /* apply runtime linkage */ mail_parameters (NIL,SET_SSLDRIVER,(void *) &ssldriver); mail_parameters (NIL,SET_SSLSTART,(void *) ssl_start); #ifdef OPENSSL_1_1_0 OPENSSL_init_ssl(0, NULL); #else SSL_library_init (); /* add all algorithms */ #endif /* OPENSSL_1_1_0 */ } } /* SSL open * Accepts: host name * contact service name * contact port number * Returns: SSL stream if success else NIL */ SSLSTREAM *ssl_open (char *host,char *service,unsigned long port) { TCPSTREAM *stream = tcp_open (host,service,port); return stream ? ssl_start (stream,host,port) : NIL; } /* SSL authenticated open * Accepts: host name * service name * returned user name buffer * Returns: SSL stream if success else NIL */ SSLSTREAM *ssl_aopen (NETMBX *mb,char *service,char *usrbuf) { return NIL; /* don't use this mechanism with SSL */ } typedef struct ssl_disable_s { int version; long disable_code; } SSL_DISABLE_S; SSL_DISABLE_S ssl_disable[] = { {SSL2_VERSION, SSL_OP_NO_SSLv2}, {SSL3_VERSION, SSL_OP_NO_SSLv3}, {TLS1_VERSION, SSL_OP_NO_TLSv1}, {TLS1_1_VERSION, SSL_OP_NO_TLSv1_1}, {TLS1_2_VERSION, SSL_OP_NO_TLSv1_2}, #ifdef TLS1_3_VERSION {TLS1_3_VERSION, SSL_OP_NO_TLSv1_3}, #endif /* TLS1_3_VERSION */ {0, 0} }; #define NUMBER_SSL_VERSIONS (sizeof(ssl_disable)/sizeof(ssl_disable[0]) - 1) /* returns the mask to disable a specific version. * If version not found, returns 0. * * Arguments: version, and direction. * If direction is -1, returns mask to disable versions less than given version. * If direction is +1, returns mask to disable versions bigger than given version. */ long ssl_disable_mask(int ssl_version, int direction) { int rv = 0; int i; for(i = 0; ssl_disable[i].version != 0 && ssl_disable[i].version != ssl_version; i++); if(i == 0 || i == NUMBER_SSL_VERSIONS - 1 || ssl_disable[i].version == 0) return rv; i += direction; /* move in the direction */ for(; i >= 0 && i <= NUMBER_SSL_VERSIONS - 1; i += direction) rv |= ssl_disable[i].disable_code; return rv; } /* ssl_connect_mthd: returns a context pointer to the connection to * a ssl server */ const SSL_METHOD *ssl_connect_mthd(int flag, int *minv, int *maxv) { int client_request; client_request = (flag & NET_TRYTLS1) ? TLS1_VERSION : (flag & NET_TRYTLS1_1) ? TLS1_1_VERSION : (flag & NET_TRYTLS1_2) ? TLS1_2_VERSION #ifdef TLS1_3_VERSION : (flag & NET_TRYTLS1_3) ? TLS1_3_VERSION #else : (flag & NET_TRYTLS1_3) ? -2 #endif : 0; *minv = *(int *) mail_parameters(NULL, GET_ENCRYPTION_RANGE_MIN, NULL); *maxv = *(int *) mail_parameters(NULL, GET_ENCRYPTION_RANGE_MAX, NULL); /* * if no special request, negotiate the maximum the client is configured * to negotiate */ if(client_request == 0) client_request = *maxv; if(client_request < *minv || client_request > *maxv) return NIL; /* out of range? bail out */ /* Some Linux distributors seem to believe that it is ok to disable some of * these methods for their users, so we have to test that every requested * method has actually been compiled in into their openssl/libressl library. * Oh well... */ #ifndef OPENSSL_1_1_0 if(client_request == SSL3_VERSION) #ifndef OPENSSL_NO_SSL3_METHOD return SSLv3_client_method(); #else return NIL; #endif /* OPENSSL_NO_SSL3_METHOD */ else if(client_request == TLS1_VERSION) #ifndef OPENSSL_NO_TLS1_METHOD return TLSv1_client_method(); #else return NIL; #endif /* OPENSSL_NO_TLS1_METHOD */ else if(client_request == TLS1_1_VERSION) #ifndef OPENSSL_NO_TLS1_1_METHOD return TLSv1_1_client_method(); #else return NIL; #endif /* OPENSSL_NO_TLS1_1_METHOD */ else if(client_request == TLS1_2_VERSION) #ifndef OPENSSL_NO_TLS1_2_METHOD return TLSv1_2_client_method(); #else return NIL; #endif /* OPENSSL_NO_TLS1_2_METHOD */ #ifdef TLS1_3_VERSION /* this is only reachable if TLS1_3 support exists */ else if(client_request == TLS1_3_VERSION) #ifndef OPENSSL_NO_TLS1_3_METHOD return TLS_client_method(); #else return NIL; #endif /* #ifndef OPENSSL_NO_TLS1_2_METHOD */ #endif /* TLS1_3_VERSION */ #endif /* ifndef OPENSSL_1_1_0 */ return SSLv23_client_method(); } /* Start SSL/TLS negotiations * Accepts: open TCP stream of session * user's host name * flags * Returns: SSL stream if success else NIL */ static SSLSTREAM *ssl_start (TCPSTREAM *tstream,char *host,unsigned long flags) { char *reason,tmp[MAILTMPLEN]; sslfailure_t sf = (sslfailure_t) mail_parameters (NIL,GET_SSLFAILURE,NIL); blocknotify_t bn = (blocknotify_t) mail_parameters (NIL,GET_BLOCKNOTIFY,NIL); void *data = (*bn) (BLOCK_SENSITIVE,NIL); SSLSTREAM *stream = (SSLSTREAM *) memset (fs_get (sizeof (SSLSTREAM)),0, sizeof (SSLSTREAM)); stream->tcpstream = tstream; /* bind TCP stream */ /* do the work */ reason = ssl_start_work (stream,host,flags); (*bn) (BLOCK_NONSENSITIVE,data); if (reason) { /* failed? */ ssl_close (stream); /* failed to do SSL */ stream = NIL; /* no stream returned */ switch (*reason) { /* analyze reason */ case '*': /* certificate failure */ ++reason; /* skip over certificate failure indication */ /* pass to error callback */ if (sf) (*sf) (host,reason,flags); else { /* no error callback, build error message */ sprintf (tmp,"Certificate failure for %.80s: %.512s",host,reason); mm_log (tmp,ERROR); } case '\0': /* user answered no to certificate callback */ if (flags & NET_TRYSSL) /* return dummy stream to stop tryssl */ stream = (SSLSTREAM *) memset (fs_get (sizeof (SSLSTREAM)),0, sizeof (SSLSTREAM)); break; default: /* non-certificate failure */ if (flags & NET_TRYSSL); /* no error output if tryssl */ /* pass to error callback */ else if (sf) (*sf) (host,reason,flags); else { /* no error callback, build error message */ sprintf (tmp,"TLS/SSL failure for %.80s: %.512s",host,reason); mm_log (tmp,ERROR); } break; } } return stream; } /* Start SSL/TLS negotiations worker routine * Accepts: SSL stream * user's host name * flags * Returns: NIL if success, else error reason */ /* evil but I had no choice */ static char *ssl_last_error = NIL; static char *ssl_last_host = NIL; static char *ssl_start_work (SSLSTREAM *stream,char *host,unsigned long flags) { BIO *bio; X509 *cert; unsigned long sl,tl; int minv, maxv; long masklow, maskhigh; char *s,*t,*err,tmp[MAILTMPLEN], buf[256]; char *CAfile, *CApath, *ciphers; sslcertificatequery_t scq = (sslcertificatequery_t) mail_parameters (NIL,GET_SSLCERTIFICATEQUERY,NIL); sslclientcert_t scc = (sslclientcert_t) mail_parameters (NIL,GET_SSLCLIENTCERT,NIL); sslclientkey_t sck = (sslclientkey_t) mail_parameters (NIL,GET_SSLCLIENTKEY,NIL); if (ssl_last_error) fs_give ((void **) &ssl_last_error); ssl_last_host = host; if (!(stream->context = SSL_CTX_new (ssl_connect_mthd(flags, &minv, &maxv)))) return "SSL context failed"; SSL_CTX_set_options (stream->context,0); masklow = ssl_disable_mask(minv, -1); maskhigh = ssl_disable_mask(maxv, 1); SSL_CTX_set_options(stream->context, masklow|maskhigh); /* disable certificate validation? */ if (flags & NET_NOVALIDATECERT) SSL_CTX_set_verify (stream->context,SSL_VERIFY_NONE,NIL); else SSL_CTX_set_verify (stream->context,SSL_VERIFY_PEER,ssl_open_verify); /* set cipher list */ ciphers = (char *) mail_parameters (NIL,GET_SSLCIPHERS,NIL); if(ciphers != NIL && *ciphers != '\0' && !SSL_CTX_set_cipher_list (stream->context,ciphers)) return "No listed ciphers recognized"; /* if a non-standard path desired */ CAfile = (char *) mail_parameters (NIL,GET_SSLCAFILE,NIL); CApath = (char *) mail_parameters (NIL,GET_SSLCAPATH,NIL); if (CAfile != NIL || CApath != NIL) SSL_CTX_load_verify_locations (stream->context, CAfile, CApath); else /* set default paths to CAs... */ SSL_CTX_set_default_verify_paths (stream->context); /* Load app certificates */ CAfile = (char *) mail_parameters (NIL,GET_SSLAPPCAFILE,NIL); CApath = (char *) mail_parameters (NIL,GET_SSLAPPCAPATH,NIL); if (CAfile != NIL || CApath != NIL) SSL_CTX_load_verify_locations (stream->context, CAfile, CApath); /* want to send client certificate? */ if (scc && (s = (*scc) ()) && (sl = strlen (s))) { if ((cert = PEM_read_bio_X509 (bio = BIO_new_mem_buf (s,sl),NIL,NIL,NIL)) != NULL) { SSL_CTX_use_certificate (stream->context,cert); X509_free (cert); } BIO_free (bio); if (!cert) return "SSL client certificate failed"; /* want to supply private key? */ if ((t = (sck ? (*sck) () : s)) && (tl = strlen (t))) { EVP_PKEY *key; if ((key = PEM_read_bio_PrivateKey (bio = BIO_new_mem_buf (t,tl), NIL,NIL,"")) != NULL) { SSL_CTX_use_PrivateKey (stream->context,key); EVP_PKEY_free (key); } BIO_free (bio); memset (t,0,tl); /* erase key */ } if (s != t) memset (s,0,sl);/* erase certificate if different from key */ } /* create connection */ if (!(stream->con = (SSL *) SSL_new (stream->context))) return "SSL connection failed"; if (host && !SSL_set_tlsext_host_name(stream->con, host)){ return "Server Name Identification (SNI) failed"; } bio = BIO_new_socket (stream->tcpstream->tcpsi,BIO_NOCLOSE); SSL_set_bio (stream->con,bio,bio); SSL_set_connect_state (stream->con); if (SSL_in_init (stream->con)) SSL_total_renegotiations (stream->con); /* now negotiate SSL */ if (SSL_write (stream->con,"",0) < 0) return ssl_last_error ? ssl_last_error : "SSL negotiation failed"; /* need to validate host names? */ cert = SSL_get_peer_certificate (stream->con); if (!(flags & NET_NOVALIDATECERT) && (err = ssl_validate_cert (cert, host))) { /* application callback */ X509_NAME_oneline (X509_get_subject_name(cert), buf, sizeof(buf)); if (scq) return (*scq) (err,host,cert ? buf : "???") ? NIL : ""; /* error message to return via mm_log() */ sprintf (tmp,"*%.128s: %.255s",err,cert ? buf : "???"); X509_free(cert); return ssl_last_error = cpystr (tmp); } X509_free(cert); return NIL; } /* SSL certificate verification callback * Accepts: error flag * X509 context * Returns: error flag */ static int ssl_open_verify (int ok,X509_STORE_CTX *ctx) { char *err,cert[256],tmp[MAILTMPLEN]; sslcertificatequery_t scq = (sslcertificatequery_t) mail_parameters (NIL,GET_SSLCERTIFICATEQUERY,NIL); if (!ok) { /* in case failure */ err = (char *) X509_verify_cert_error_string (X509_STORE_CTX_get_error (ctx)); X509_NAME_oneline (X509_get_subject_name (X509_STORE_CTX_get_current_cert (ctx)),cert,255); if (!scq) { /* mm_log() error message if no callback */ sprintf (tmp,"*%.128s: %.255s",err,cert); ssl_last_error = cpystr (tmp); } /* ignore error if application says to */ else if ((*scq) (err,ssl_last_host,cert)) ok = T; /* application wants punt */ else ssl_last_error = cpystr (""); } return ok; } /* SSL validate certificate * Accepts: certificate * host to validate against * Returns: NIL if validated, else string of error message */ static char *ssl_validate_cert (X509 *cert,char *host) { int i,j,n, m = 0; char *s=NULL,*t,*ret = NIL; void *ext = NIL; GENERAL_NAME *name; X509_NAME *cname; X509_NAME_ENTRY *e; char buf[256]; /* make sure have a certificate */ if (!cert) return "No certificate from server"; /* Method 1: locate CN */ #ifndef OPENSSL_1_1_0 if (cert->name == NIL) ret = "No name in certificate"; else if ((s = strstr (cert->name,"/CN=")) != NIL) { m++; /* count that we tried this method */ if ((t = strchr (s += 4,'/')) != NIL) *t = '\0'; /* host name matches pattern? */ ret = ssl_compare_hostnames (host,s) ? NIL : "Server name does not match certificate"; if (t) *t = '/'; /* restore smashed delimiter */ /* if mismatch, see if in extensions */ if (ret && (ext = X509_get_ext_d2i (cert,NID_subject_alt_name,NIL,NIL)) && (n = sk_GENERAL_NAME_num (ext))) /* older versions of OpenSSL use "ia5" instead of dNSName */ for (i = 0; ret && (i < n); i++) if ((name = sk_GENERAL_NAME_value (ext,i)) && (name->type = GEN_DNS) && (s = name->d.ia5->data) && ssl_compare_hostnames (host,s)) ret = NIL; if(ext) GENERAL_NAMES_free(ext); } #endif /* OPENSSL_1_1_0 */ /* Method 2, use cname */ if(m == 0 || ret != NIL){ cname = X509_get_subject_name(cert); for(j = 0, ret = NIL; j < X509_NAME_entry_count(cname) && ret == NIL; j++){ if((e = X509_NAME_get_entry(cname, j)) != NULL){ X509_NAME_get_text_by_OBJ(cname, X509_NAME_ENTRY_get_object(e), buf, sizeof(buf)); s = (char *) buf; } else s = NIL; if (s != NIL) { /* host name matches pattern? */ ret = ssl_compare_hostnames (host,s) ? NIL : "Server name does not match certificate"; ext = NIL; /* if mismatch, see if in extensions */ if (ret && (ext = X509_get_ext_d2i (cert,NID_subject_alt_name,NIL,NIL)) && (n = sk_GENERAL_NAME_num (ext))) /* older versions of OpenSSL use "ia5" instead of dNSName */ for (i = 0; ret && (i < n); i++) if ((name = sk_GENERAL_NAME_value (ext,i)) && (name->type = GEN_DNS) && (s = name->d.ia5->data) && ssl_compare_hostnames (host,s)) ret = NIL; if(ext) GENERAL_NAMES_free(ext); } } } if (ret == NIL #ifndef OPENSSL_1_1_0 && !cert->name #endif /* OPENSSL_1_1_0 */ && !X509_get_subject_name(cert)) ret = "No name in certificate"; if (ret == NIL && s == NIL) ret = "Unable to locate common name in certificate"; return ret; } /* Case-independent wildcard pattern match * Accepts: base string * pattern string * Returns: T if pattern matches base, else NIL */ static long ssl_compare_hostnames (unsigned char *s,unsigned char *pat) { long ret = NIL; switch (*pat) { case '*': /* wildcard */ if (pat[1]) { /* there must be a pattern suffix */ /* there is, scan base against it */ do if (ssl_compare_hostnames (s,pat+1)) ret = LONGT; while (!ret && (*s != '.') && *s++); } break; case '\0': /* end of pattern */ if (!*s) ret = LONGT; /* success if base is also at end */ break; default: /* non-wildcard, recurse if match */ if (!compare_uchar (*pat,*s)) ret = ssl_compare_hostnames (s+1,pat+1); break; } return ret; } /* SSL receive line * Accepts: SSL stream * Returns: text line string or NIL if failure */ char *ssl_getline (SSLSTREAM *stream) { unsigned long n,contd; char *ret = ssl_getline_work (stream,&n,&contd); if (ret && contd) { /* got a line needing continuation? */ STRINGLIST *stl = mail_newstringlist (); STRINGLIST *stc = stl; do { /* collect additional lines */ stc->text.data = (unsigned char *) ret; stc->text.size = n; stc = stc->next = mail_newstringlist (); ret = ssl_getline_work (stream,&n,&contd); } while (ret && contd); if (ret) { /* stash final part of line on list */ stc->text.data = (unsigned char *) ret; stc->text.size = n; /* determine how large a buffer we need */ for (n = 0, stc = stl; stc; stc = stc->next) n += stc->text.size; ret = fs_get (n + 1); /* copy parts into buffer */ for (n = 0, stc = stl; stc; n += stc->text.size, stc = stc->next) memcpy (ret + n,stc->text.data,stc->text.size); ret[n] = '\0'; } mail_free_stringlist (&stl);/* either way, done with list */ } return ret; } char *ssl_getsize (SSLSTREAM *stream, unsigned long size) { char *ret = NIL; unsigned long got = 0L, need = size, n; do { if(!ssl_getdata (stream)) return ret; /* return what we have */ n = stream->ictr < need ? stream->ictr : need; fs_resize((void **) &ret, (got + n + 1)*sizeof(char)); memcpy(ret + got, stream->iptr, n); ret[got+n] = '\0'; got += n; need -= n; stream->iptr += n; stream->ictr -= n; } while (need > 0); return ret; } /* SSL receive line or partial line * Accepts: SSL stream * pointer to return size * pointer to return continuation flag * Returns: text line string, size and continuation flag, or NIL if failure */ static char *ssl_getline_work (SSLSTREAM *stream,unsigned long *size, long *contd) { unsigned long n; char *s,*ret,c,d; *contd = NIL; /* assume no continuation */ /* make sure have data */ if (!ssl_getdata (stream)) return NIL; for (s = stream->iptr, n = 0, c = '\0'; stream->ictr--; n++, c = d) { d = *stream->iptr++; /* slurp another character */ if ((c == '\015') && (d == '\012')) { ret = (char *) fs_get (n--); memcpy (ret,s,*size = n); /* copy into a free storage string */ ret[n] = '\0'; /* tie off string with null */ return ret; } } /* copy partial string from buffer */ memcpy ((ret = (char *) fs_get (n)),s,*size = n); /* get more data from the net */ if (!ssl_getdata (stream)) fs_give ((void **) &ret); /* special case of newline broken by buffer */ else if ((c == '\015') && (*stream->iptr == '\012')) { stream->iptr++; /* eat the line feed */ stream->ictr--; ret[*size = --n] = '\0'; /* tie off string with null */ } else *contd = LONGT; /* continuation needed */ return ret; } /* SSL receive buffer * Accepts: SSL stream * size in bytes * buffer to read into * Returns: T if success, NIL otherwise */ long ssl_getbuffer (SSLSTREAM *stream,unsigned long size,char *buffer) { unsigned long n; while (size > 0) { /* until request satisfied */ if (!ssl_getdata (stream)) return NIL; n = min (size,stream->ictr);/* number of bytes to transfer */ /* do the copy */ memcpy (buffer,stream->iptr,n); buffer += n; /* update pointer */ stream->iptr += n; size -= n; /* update # of bytes to do */ stream->ictr -= n; } buffer[0] = '\0'; /* tie off string */ return T; } /* SSL receive data * Accepts: TCP/IP stream * Returns: T if success, NIL otherwise */ long ssl_getdata (SSLSTREAM *stream) { int i,sock; fd_set fds,efds; struct timeval tmo; tcptimeout_t tmoh = (tcptimeout_t) mail_parameters (NIL,GET_TIMEOUT,NIL); long ttmo_read = (long) mail_parameters (NIL,GET_READTIMEOUT,NIL); time_t t = time (0); blocknotify_t bn = (blocknotify_t) mail_parameters (NIL,GET_BLOCKNOTIFY,NIL); if (!stream->con || ((sock = SSL_get_fd (stream->con)) < 0)) return NIL; /* tcp_unix should have prevented this */ if (sock >= FD_SETSIZE) fatal ("unselectable socket in ssl_getdata()"); (*bn) (BLOCK_TCPREAD,NIL); while (stream->ictr < 1) { /* if nothing in the buffer */ time_t tl = time (0); /* start of request */ time_t now = tl; int ti = ttmo_read ? now + ttmo_read : 0; if (SSL_pending (stream->con)) i = 1; else { if (tcpdebug) mm_log ("Reading SSL data",TCPDEBUG); tmo.tv_usec = 0; FD_ZERO (&fds); /* initialize selection vector */ FD_ZERO (&efds); /* handle errors too */ FD_SET (sock,&fds); /* set bit in selection vector */ FD_SET (sock,&efds); /* set bit in error selection vector */ errno = NIL; /* block and read */ do { /* block under timeout */ tmo.tv_sec = ti ? ti - now : 0; i = select (sock+1,&fds,0,&efds,ti ? &tmo : 0); now = time (0); /* fake timeout if interrupt & time expired */ if ((i < 0) && (errno == EINTR) && ti && (ti <= now)) i = 0; } while ((i < 0) && (errno == EINTR)); } if (i) { /* non-timeout result from select? */ errno = 0; /* just in case */ if (i > 0) /* read what we can */ while (((i = SSL_read (stream->con,stream->ibuf,SSLBUFLEN)) < 0) && ((errno == EINTR) || (SSL_get_error (stream->con,i) == SSL_ERROR_WANT_READ))); if (i <= 0) { /* error seen? */ if (tcpdebug) { char *s,tmp[MAILTMPLEN]; if (i) sprintf (s = tmp,"SSL data read I/O error %d SSL error %d", errno,SSL_get_error (stream->con,i)); else s = "SSL data read end of file"; mm_log (s,TCPDEBUG); } return ssl_abort (stream); } stream->iptr = stream->ibuf;/* point at TCP buffer */ stream->ictr = i; /* set new byte count */ if (tcpdebug) mm_log ("Successfully read SSL data",TCPDEBUG); } /* timeout, punt unless told not to */ else if (!tmoh || !(*tmoh) (now - t,now - tl, stream->tcpstream->host)) { if (tcpdebug) mm_log ("SSL data read timeout",TCPDEBUG); return ssl_abort (stream); } } (*bn) (BLOCK_NONE,NIL); return T; } /* SSL send string as record * Accepts: SSL stream * string pointer * Returns: T if success else NIL */ long ssl_soutr (SSLSTREAM *stream,char *string) { return ssl_sout (stream,string,(unsigned long) strlen (string)); } /* SSL send string * Accepts: SSL stream * string pointer * byte count * Returns: T if success else NIL */ long ssl_sout (SSLSTREAM *stream,char *string,unsigned long size) { long i; blocknotify_t bn = (blocknotify_t) mail_parameters (NIL,GET_BLOCKNOTIFY,NIL); if (!stream->con) return NIL; (*bn) (BLOCK_TCPWRITE,NIL); if (tcpdebug) mm_log ("Writing to SSL",TCPDEBUG); /* until request satisfied */ for (i = 0; size > 0; string += i,size -= i) /* write as much as we can */ if ((i = SSL_write (stream->con,string,(int) min (SSLBUFLEN,size))) < 0) { if (tcpdebug) { char tmp[MAILTMPLEN]; sprintf (tmp,"SSL data write I/O error %d SSL error %d", errno,SSL_get_error (stream->con,i)); mm_log (tmp,TCPDEBUG); } return ssl_abort (stream);/* write failed */ } if (tcpdebug) mm_log ("successfully wrote to TCP",TCPDEBUG); (*bn) (BLOCK_NONE,NIL); return LONGT; /* all done */ } /* SSL close * Accepts: SSL stream */ void ssl_close (SSLSTREAM *stream) { ssl_abort (stream); /* nuke the stream */ fs_give ((void **) &stream); /* flush the stream */ } /* SSL abort stream * Accepts: SSL stream * Returns: NIL always */ static long ssl_abort (SSLSTREAM *stream) { blocknotify_t bn = (blocknotify_t) mail_parameters (NIL,GET_BLOCKNOTIFY,NIL); if (stream->con) { /* close SSL connection */ SSL_shutdown (stream->con); SSL_free (stream->con); stream->con = NIL; } if (stream->context) { /* clean up context */ SSL_CTX_free (stream->context); stream->context = NIL; } if (stream->tcpstream) { /* close TCP stream */ tcp_close (stream->tcpstream); stream->tcpstream = NIL; } (*bn) (BLOCK_NONE,NIL); return NIL; } /* SSL get host name * Accepts: SSL stream * Returns: host name for this stream */ char *ssl_host (SSLSTREAM *stream) { return stream ? tcp_host (stream->tcpstream) : "UNKNOWN"; } /* SSL get remote host name * Accepts: SSL stream * Returns: host name for this stream */ char *ssl_remotehost (SSLSTREAM *stream) { return tcp_remotehost (stream->tcpstream); } /* SSL return port for this stream * Accepts: SSL stream * Returns: port number for this stream */ unsigned long ssl_port (SSLSTREAM *stream) { return tcp_port (stream->tcpstream); } /* SSL get local host name * Accepts: SSL stream * Returns: local host name */ char *ssl_localhost (SSLSTREAM *stream) { return tcp_localhost (stream->tcpstream); } /* Start TLS * Accepts: /etc/services service name * Returns: cpystr'd error string if TLS failed, else NIL for success */ char *ssl_start_tls (char *server) { char tmp[MAILTMPLEN]; struct stat sbuf; if (sslstdio) return cpystr ("Already in an SSL session"); if (start_tls) return cpystr ("TLS already started"); if (server) { /* build specific certificate/key file name */ sprintf (tmp,"%s/%s-%s.pem",SSL_CERT_DIRECTORY,server,tcp_serveraddr ()); if (stat (tmp,&sbuf)) { /* use non-specific name if no specific file */ sprintf (tmp,"%s/%s.pem",SSL_CERT_DIRECTORY,server); if (stat (tmp,&sbuf)) return cpystr ("Server certificate not installed"); } start_tls = server; /* switch to STARTTLS mode */ } return NIL; } /* Init server for SSL * Accepts: server name */ void ssl_server_init (char *server) { char cert[MAILTMPLEN],key[MAILTMPLEN]; unsigned long i; struct stat sbuf; SSLSTREAM *stream = (SSLSTREAM *) memset (fs_get (sizeof (SSLSTREAM)),0, sizeof (SSLSTREAM)); ssl_onceonlyinit (); /* make sure algorithms added */ #ifdef OPENSSL_1_1_0 OPENSSL_init_crypto(OPENSSL_INIT_LOAD_CRYPTO_STRINGS, NULL); OPENSSL_init_ssl(OPENSSL_INIT_LOAD_SSL_STRINGS|OPENSSL_INIT_LOAD_CRYPTO_STRINGS, NULL); #else ERR_load_crypto_strings (); SSL_load_error_strings (); #endif /* OPENSSL_1_1_0 */ /* build specific certificate/key file names */ sprintf (cert,"%s/%s-%s.pem",SSL_CERT_DIRECTORY,server,tcp_serveraddr ()); sprintf (key,"%s/%s-%s.pem",SSL_KEY_DIRECTORY,server,tcp_serveraddr ()); /* use non-specific name if no specific cert */ if (stat (cert,&sbuf)) sprintf (cert,"%s/%s.pem",SSL_CERT_DIRECTORY,server); if (stat (key,&sbuf)) { /* use non-specific name if no specific key */ sprintf (key,"%s/%s.pem",SSL_KEY_DIRECTORY,server); /* use cert file as fallback for key */ if (stat (key,&sbuf)) strcpy (key,cert); } /* create context */ #ifdef OPENSSL_1_1_0 if (!(stream->context = SSL_CTX_new (start_tls ? TLS_server_method () : SSLv23_server_method ()))) #else if (!(stream->context = SSL_CTX_new (start_tls ? TLSv1_server_method () : SSLv23_server_method ()))) #endif /* OPENSSL_1_1_0 */ syslog (LOG_ALERT,"Unable to create SSL context, host=%.80s", tcp_clienthost ()); else { /* set context options */ SSL_CTX_set_options (stream->context,SSL_OP_ALL); /* set cipher list */ if (!SSL_CTX_set_cipher_list (stream->context,SSLCIPHERLIST)) syslog (LOG_ALERT,"Unable to set cipher list %.80s, host=%.80s", SSLCIPHERLIST,tcp_clienthost ()); /* load certificate */ else if (!SSL_CTX_use_certificate_chain_file (stream->context,cert)) syslog (LOG_ALERT,"Unable to load certificate from %.80s, host=%.80s", cert,tcp_clienthost ()); /* load key */ else if (!(SSL_CTX_use_RSAPrivateKey_file (stream->context,key, SSL_FILETYPE_PEM))) syslog (LOG_ALERT,"Unable to load private key from %.80s, host=%.80s", key,tcp_clienthost ()); else { /* generate key if needed */ #ifdef OPENSSL_1_1_0 if (0) ssl_genkey(stream->context, 0, 0); #else if (SSL_CTX_need_tmp_RSA (stream->context)) SSL_CTX_set_tmp_rsa_callback (stream->context,ssl_genkey); #endif /* OPENSSL_1_1_0 */ /* create new SSL connection */ if (!(stream->con = SSL_new (stream->context))) syslog (LOG_ALERT,"Unable to create SSL connection, host=%.80s", tcp_clienthost ()); else { /* set file descriptor */ SSL_set_fd (stream->con,0); /* all OK if accepted */ if (SSL_accept (stream->con) < 0) syslog (LOG_INFO,"Unable to accept SSL connection, host=%.80s", tcp_clienthost ()); else { /* server set up */ sslstdio = (SSLSTDIOSTREAM *) memset (fs_get (sizeof(SSLSTDIOSTREAM)),0,sizeof (SSLSTDIOSTREAM)); sslstdio->sslstream = stream; /* available space in output buffer */ sslstdio->octr = SSLBUFLEN; /* current output buffer pointer */ sslstdio->optr = sslstdio->obuf; /* allow plaintext if disable value was 2 */ if ((long) mail_parameters (NIL,GET_DISABLEPLAINTEXT,NIL) > 1) mail_parameters (NIL,SET_DISABLEPLAINTEXT,NIL); /* unhide PLAIN SASL authenticator */ mail_parameters (NIL,UNHIDE_AUTHENTICATOR,"PLAIN"); mail_parameters (NIL,UNHIDE_AUTHENTICATOR,"LOGIN"); return; } } } } while ((i = ERR_get_error ()) != 0L) /* SSL failure */ syslog (LOG_ERR,"SSL error status: %.80s",ERR_error_string (i,NIL)); ssl_close (stream); /* punt stream */ exit (1); /* punt this program too */ } /* Generate one-time key for server * Accepts: SSL connection * export flag * keylength * Returns: generated key, always */ static RSA *ssl_genkey (SSL_CTX_TYPE *con,int export,int keylength) { unsigned long i; static RSA *key = NIL; if (!key) { /* if don't have a key already */ /* generate key */ #ifdef OPENSSL_1_1_0 BIGNUM *e = BN_new(); if (!RSA_generate_key_ex (key, export ? keylength : 1024, e,NIL)) { #else if (!(key = RSA_generate_key (export ? keylength : 1024,RSA_F4,NIL,NIL))) { #endif /* OPENSSL_1_1_0 */ syslog (LOG_ALERT,"Unable to generate temp key, host=%.80s", tcp_clienthost ()); while ((i = ERR_get_error ()) != 0L) syslog (LOG_ALERT,"SSL error status: %s",ERR_error_string (i,NIL)); exit (1); } #ifdef OPENSSL_1_1_0 BN_free(e); e = NULL; #endif /* OPENSSL_1_1_0 */ } return key; } /* Wait for stdin input * Accepts: timeout in seconds * Returns: T if have input on stdin, else NIL */ long ssl_server_input_wait (long seconds) { int i,sock; fd_set fds,efd; struct timeval tmo; SSLSTREAM *stream; if (!sslstdio) return server_input_wait (seconds); /* input available in buffer */ if (((stream = sslstdio->sslstream)->ictr > 0) || !stream->con || ((sock = SSL_get_fd (stream->con)) < 0)) return LONGT; /* sock ought to be 0 always */ if (sock >= FD_SETSIZE) fatal ("unselectable socket in ssl_getdata()"); /* input available from SSL */ if (SSL_pending (stream->con) && ((i = SSL_read (stream->con,stream->ibuf,SSLBUFLEN)) > 0)) { stream->iptr = stream->ibuf;/* point at TCP buffer */ stream->ictr = i; /* set new byte count */ return LONGT; } FD_ZERO (&fds); /* initialize selection vector */ FD_ZERO (&efd); /* initialize selection vector */ FD_SET (sock,&fds); /* set bit in selection vector */ FD_SET (sock,&efd); /* set bit in selection vector */ tmo.tv_sec = seconds; tmo.tv_usec = 0; /* see if input available from the socket */ return select (sock+1,&fds,0,&efd,&tmo) ? LONGT : NIL; } #include "sslstdio.c"