/*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1998-2016 Dag-Erling Smørgrav * Copyright (c) 2013 Michael Gmelin * 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 * in this position and unchanged. * 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 of the author may not be used to endorse or promote products * derived from this software without specific prior written permission * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef WITH_SSL #include #endif #include "fetch.h" #include "common.h" /*** Local data **************************************************************/ /* * Error messages for resolver errors */ static struct fetcherr netdb_errlist[] = { #ifdef EAI_ADDRFAMILY { EAI_ADDRFAMILY, FETCH_RESOLV, "Address family for host not supported" }, #endif #ifdef EAI_NODATA { EAI_NODATA, FETCH_RESOLV, "No address for host" }, #endif { EAI_AGAIN, FETCH_TEMP, "Transient resolver failure" }, { EAI_FAIL, FETCH_RESOLV, "Non-recoverable resolver failure" }, { EAI_NONAME, FETCH_RESOLV, "Host does not resolve" }, { -1, FETCH_UNKNOWN, "Unknown resolver error" } }; /* * SOCKS5 error enumerations */ enum SOCKS5_ERR { /* Protocol errors */ SOCKS5_ERR_SELECTION, SOCKS5_ERR_READ_METHOD, SOCKS5_ERR_VER5_ONLY, SOCKS5_ERR_NOMETHODS, SOCKS5_ERR_NOTIMPLEMENTED, SOCKS5_ERR_HOSTNAME_SIZE, SOCKS5_ERR_REQUEST, SOCKS5_ERR_REPLY, SOCKS5_ERR_NON_VER5_RESP, SOCKS5_ERR_GENERAL, SOCKS5_ERR_NOT_ALLOWED, SOCKS5_ERR_NET_UNREACHABLE, SOCKS5_ERR_HOST_UNREACHABLE, SOCKS5_ERR_CONN_REFUSED, SOCKS5_ERR_TTL_EXPIRED, SOCKS5_ERR_COM_UNSUPPORTED, SOCKS5_ERR_ADDR_UNSUPPORTED, SOCKS5_ERR_UNSPECIFIED, /* Configuration errors */ SOCKS5_ERR_BAD_HOST, SOCKS5_ERR_BAD_PROXY_FORMAT, SOCKS5_ERR_BAD_PORT }; /* * Error messages for SOCKS5 errors */ static struct fetcherr socks5_errlist[] = { /* SOCKS5 protocol errors */ { SOCKS5_ERR_SELECTION, FETCH_ABORT, "SOCKS5: Failed to send selection method" }, { SOCKS5_ERR_READ_METHOD, FETCH_ABORT, "SOCKS5: Failed to read method" }, { SOCKS5_ERR_VER5_ONLY, FETCH_PROTO, "SOCKS5: Only version 5 is implemented" }, { SOCKS5_ERR_NOMETHODS, FETCH_PROTO, "SOCKS5: No acceptable methods" }, { SOCKS5_ERR_NOTIMPLEMENTED, FETCH_PROTO, "SOCKS5: Method currently not implemented" }, { SOCKS5_ERR_HOSTNAME_SIZE, FETCH_PROTO, "SOCKS5: Hostname size is above 256 bytes" }, { SOCKS5_ERR_REQUEST, FETCH_PROTO, "SOCKS5: Failed to request" }, { SOCKS5_ERR_REPLY, FETCH_PROTO, "SOCKS5: Failed to receive reply" }, { SOCKS5_ERR_NON_VER5_RESP, FETCH_PROTO, "SOCKS5: Server responded with a non-version 5 response" }, { SOCKS5_ERR_GENERAL, FETCH_ABORT, "SOCKS5: General server failure" }, { SOCKS5_ERR_NOT_ALLOWED, FETCH_AUTH, "SOCKS5: Connection not allowed by ruleset" }, { SOCKS5_ERR_NET_UNREACHABLE, FETCH_NETWORK, "SOCKS5: Network unreachable" }, { SOCKS5_ERR_HOST_UNREACHABLE, FETCH_ABORT, "SOCKS5: Host unreachable" }, { SOCKS5_ERR_CONN_REFUSED, FETCH_ABORT, "SOCKS5: Connection refused" }, { SOCKS5_ERR_TTL_EXPIRED, FETCH_TIMEOUT, "SOCKS5: TTL expired" }, { SOCKS5_ERR_COM_UNSUPPORTED, FETCH_PROTO, "SOCKS5: Command not supported" }, { SOCKS5_ERR_ADDR_UNSUPPORTED, FETCH_ABORT, "SOCKS5: Address type not supported" }, { SOCKS5_ERR_UNSPECIFIED, FETCH_UNKNOWN, "SOCKS5: Unspecified error" }, /* Configuration error */ { SOCKS5_ERR_BAD_HOST, FETCH_ABORT, "SOCKS5: Bad proxy host" }, { SOCKS5_ERR_BAD_PROXY_FORMAT, FETCH_ABORT, "SOCKS5: Bad proxy format" }, { SOCKS5_ERR_BAD_PORT, FETCH_ABORT, "SOCKS5: Bad port" } }; /* End-of-Line */ static const char ENDL[2] = "\r\n"; /*** Error-reporting functions ***********************************************/ /* * Map error code to string */ static struct fetcherr * fetch_finderr(struct fetcherr *p, int e) { while (p->num != -1 && p->num != e) p++; return (p); } /* * Set error code */ void fetch_seterr(struct fetcherr *p, int e) { p = fetch_finderr(p, e); fetchLastErrCode = p->cat; snprintf(fetchLastErrString, MAXERRSTRING, "%s", p->string); } /* * Set error code according to errno */ void fetch_syserr(void) { switch (errno) { case 0: fetchLastErrCode = FETCH_OK; break; case EPERM: case EACCES: case EROFS: case EAUTH: case ENEEDAUTH: fetchLastErrCode = FETCH_AUTH; break; case ENOENT: case EISDIR: /* XXX */ fetchLastErrCode = FETCH_UNAVAIL; break; case ENOMEM: fetchLastErrCode = FETCH_MEMORY; break; case EBUSY: case EAGAIN: fetchLastErrCode = FETCH_TEMP; break; case EEXIST: fetchLastErrCode = FETCH_EXISTS; break; case ENOSPC: fetchLastErrCode = FETCH_FULL; break; case EADDRINUSE: case EADDRNOTAVAIL: case ENETDOWN: case ENETUNREACH: case ENETRESET: case EHOSTUNREACH: fetchLastErrCode = FETCH_NETWORK; break; case ECONNABORTED: case ECONNRESET: fetchLastErrCode = FETCH_ABORT; break; case ETIMEDOUT: fetchLastErrCode = FETCH_TIMEOUT; break; case ECONNREFUSED: case EHOSTDOWN: fetchLastErrCode = FETCH_DOWN; break; default: fetchLastErrCode = FETCH_UNKNOWN; } snprintf(fetchLastErrString, MAXERRSTRING, "%s", strerror(errno)); } /* * Emit status message */ void fetch_info(const char *fmt, ...) { va_list ap; va_start(ap, fmt); vfprintf(stderr, fmt, ap); va_end(ap); fputc('\n', stderr); } /*** Network-related utility functions ***************************************/ /* * Return the default port for a scheme */ int fetch_default_port(const char *scheme) { struct servent *se; if ((se = getservbyname(scheme, "tcp")) != NULL) return (ntohs(se->s_port)); if (strcmp(scheme, SCHEME_FTP) == 0) return (FTP_DEFAULT_PORT); if (strcmp(scheme, SCHEME_HTTP) == 0) return (HTTP_DEFAULT_PORT); return (0); } /* * Return the default proxy port for a scheme */ int fetch_default_proxy_port(const char *scheme) { if (strcmp(scheme, SCHEME_FTP) == 0) return (FTP_DEFAULT_PROXY_PORT); if (strcmp(scheme, SCHEME_HTTP) == 0) return (HTTP_DEFAULT_PROXY_PORT); return (0); } /* * Create a connection for an existing descriptor. */ conn_t * fetch_reopen(int sd) { conn_t *conn; int opt = 1; /* allocate and fill connection structure */ if ((conn = calloc(1, sizeof(*conn))) == NULL) return (NULL); fcntl(sd, F_SETFD, FD_CLOEXEC); setsockopt(sd, SOL_SOCKET, SO_NOSIGPIPE, &opt, sizeof opt); conn->sd = sd; ++conn->ref; return (conn); } /* * Bump a connection's reference count. */ conn_t * fetch_ref(conn_t *conn) { ++conn->ref; return (conn); } /* * Resolve an address */ struct addrinfo * fetch_resolve(const char *addr, int port, int af) { char hbuf[256], sbuf[8]; struct addrinfo hints, *res; const char *hb, *he, *sep; const char *host, *service; int err, len; /* first, check for a bracketed IPv6 address */ if (*addr == '[') { hb = addr + 1; if ((sep = strchr(hb, ']')) == NULL) { errno = EINVAL; goto syserr; } he = sep++; } else { hb = addr; sep = strchrnul(hb, ':'); he = sep; } /* see if we need to copy the host name */ if (*he != '\0') { len = snprintf(hbuf, sizeof(hbuf), "%.*s", (int)(he - hb), hb); if (len < 0) goto syserr; if (len >= (int)sizeof(hbuf)) { errno = ENAMETOOLONG; goto syserr; } host = hbuf; } else { host = hb; } /* was it followed by a service name? */ if (*sep == '\0' && port != 0) { if (port < 1 || port > 65535) { errno = EINVAL; goto syserr; } if (snprintf(sbuf, sizeof(sbuf), "%d", port) < 0) goto syserr; service = sbuf; } else if (*sep != '\0') { service = sep + 1; } else { service = NULL; } /* resolve */ memset(&hints, 0, sizeof(hints)); hints.ai_family = af; hints.ai_socktype = SOCK_STREAM; hints.ai_flags = AI_ADDRCONFIG; if ((err = getaddrinfo(host, service, &hints, &res)) != 0) { netdb_seterr(err); return (NULL); } return (res); syserr: fetch_syserr(); return (NULL); } /* * Bind a socket to a specific local address */ int fetch_bind(int sd, int af, const char *addr) { struct addrinfo *cliai, *ai; int err; if ((cliai = fetch_resolve(addr, 0, af)) == NULL) return (-1); for (ai = cliai; ai != NULL; ai = ai->ai_next) if ((err = bind(sd, ai->ai_addr, ai->ai_addrlen)) == 0) break; if (err != 0) fetch_syserr(); freeaddrinfo(cliai); return (err == 0 ? 0 : -1); } /* * SOCKS5 connection initiation, based on RFC 1928 * Default DNS resolution over SOCKS5 */ int fetch_socks5_init(conn_t *conn, const char *host, int port, int verbose) { /* * Size is based on largest packet prefix (4 bytes) + * Largest FQDN (256) + one byte size (1) + * Port (2) */ unsigned char buf[BUFF_SIZE]; unsigned char *ptr; int ret = 1; if (verbose) fetch_info("Initializing SOCKS5 connection: %s:%d", host, port); /* Connection initialization */ ptr = buf; *ptr++ = SOCKS_VERSION_5; *ptr++ = SOCKS_CONNECTION; *ptr++ = SOCKS_RSV; if (fetch_write(conn, buf, 3) != 3) { ret = SOCKS5_ERR_SELECTION; goto fail; } /* Verify response from SOCKS5 server */ if (fetch_read(conn, buf, 2) != 2) { ret = SOCKS5_ERR_READ_METHOD; goto fail; } ptr = buf; if (ptr[0] != SOCKS_VERSION_5) { ret = SOCKS5_ERR_VER5_ONLY; goto fail; } if (ptr[1] == SOCKS_NOMETHODS) { ret = SOCKS5_ERR_NOMETHODS; goto fail; } else if (ptr[1] != SOCKS5_NOTIMPLEMENTED) { ret = SOCKS5_ERR_NOTIMPLEMENTED; goto fail; } /* Send Request */ *ptr++ = SOCKS_VERSION_5; *ptr++ = SOCKS_CONNECTION; *ptr++ = SOCKS_RSV; /* Encode all targets as a hostname to avoid DNS leaks */ *ptr++ = SOCKS_ATYP_DOMAINNAME; if (strlen(host) > FQDN_SIZE) { ret = SOCKS5_ERR_HOSTNAME_SIZE; goto fail; } *ptr++ = strlen(host); memcpy(ptr, host, strlen(host)); ptr = ptr + strlen(host); port = htons(port); *ptr++ = port & 0x00ff; *ptr++ = (port & 0xff00) >> 8; if (fetch_write(conn, buf, ptr - buf) != ptr - buf) { ret = SOCKS5_ERR_REQUEST; goto fail; } /* BND.ADDR is variable length, read the largest on non-blocking socket */ if (!fetch_read(conn, buf, BUFF_SIZE)) { ret = SOCKS5_ERR_REPLY; goto fail; } ptr = buf; if (*ptr++ != SOCKS_VERSION_5) { ret = SOCKS5_ERR_NON_VER5_RESP; goto fail; } switch(*ptr++) { case SOCKS_SUCCESS: break; case SOCKS_GENERAL_FAILURE: ret = SOCKS5_ERR_GENERAL; goto fail; case SOCKS_CONNECTION_NOT_ALLOWED: ret = SOCKS5_ERR_NOT_ALLOWED; goto fail; case SOCKS_NETWORK_UNREACHABLE: ret = SOCKS5_ERR_NET_UNREACHABLE; goto fail; case SOCKS_HOST_UNREACHABLE: ret = SOCKS5_ERR_HOST_UNREACHABLE; goto fail; case SOCKS_CONNECTION_REFUSED: ret = SOCKS5_ERR_CONN_REFUSED; goto fail; case SOCKS_TTL_EXPIRED: ret = SOCKS5_ERR_TTL_EXPIRED; goto fail; case SOCKS_COMMAND_NOT_SUPPORTED: ret = SOCKS5_ERR_COM_UNSUPPORTED; goto fail; case SOCKS_ADDRESS_NOT_SUPPORTED: ret = SOCKS5_ERR_ADDR_UNSUPPORTED; goto fail; default: ret = SOCKS5_ERR_UNSPECIFIED; goto fail; } return (ret); fail: socks5_seterr(ret); return (0); } /* * Perform SOCKS5 initialization */ int fetch_socks5_getenv(char **host, int *port) { char *socks5env, *endptr, *ext; const char *portDelim; size_t slen; portDelim = ":"; if ((socks5env = getenv("SOCKS5_PROXY")) == NULL || *socks5env == '\0') { *host = NULL; *port = -1; return (-1); } /* * IPv6 addresses begin and end in brackets. Set the port delimiter * accordingly and search for it so we can do appropriate validation. */ if (socks5env[0] == '[') portDelim = "]:"; slen = strlen(socks5env); ext = strstr(socks5env, portDelim); if (socks5env[0] == '[') { if (socks5env[slen - 1] == ']') { *host = strndup(socks5env, slen); } else if (ext != NULL) { *host = strndup(socks5env, ext - socks5env + 1); } else { socks5_seterr(SOCKS5_ERR_BAD_PROXY_FORMAT); return (0); } } else { *host = strndup(socks5env, ext - socks5env); } if (*host == NULL) { fprintf(stderr, "Failure to allocate memory, exiting.\n"); return (-1); } if (ext == NULL) { *port = 1080; /* Default port as defined in RFC1928 */ } else { ext += strlen(portDelim); errno = 0; *port = strtoimax(ext, (char **)&endptr, 10); if (*endptr != '\0' || errno != 0 || *port < 0 || *port > 65535) { free(*host); *host = NULL; socks5_seterr(SOCKS5_ERR_BAD_PORT); return (0); } } return (2); } /* * Establish a TCP connection to the specified port on the specified host. */ conn_t * fetch_connect(const char *host, int port, int af, int verbose) { struct addrinfo *cais = NULL, *sais = NULL, *cai, *sai; const char *bindaddr; conn_t *conn = NULL; int err = 0, sd = -1; char *sockshost; int socksport; DEBUGF("---> %s:%d\n", host, port); /* * Check if SOCKS5_PROXY env variable is set. fetch_socks5_getenv * will either set sockshost = NULL or allocate memory in all cases. */ sockshost = NULL; if (!fetch_socks5_getenv(&sockshost, &socksport)) goto fail; /* Not using SOCKS5 proxy */ if (sockshost == NULL) { /* resolve server address */ if (verbose) fetch_info("resolving server address: %s:%d", host, port); if ((sais = fetch_resolve(host, port, af)) == NULL) goto fail; /* resolve client address */ bindaddr = getenv("FETCH_BIND_ADDRESS"); if (bindaddr != NULL && *bindaddr != '\0') { if (verbose) fetch_info("resolving client address: %s", bindaddr); if ((cais = fetch_resolve(bindaddr, 0, af)) == NULL) goto fail; } } else { /* resolve socks5 proxy address */ if (verbose) fetch_info("resolving SOCKS5 server address: %s:%d", sockshost, socksport); if ((sais = fetch_resolve(sockshost, socksport, af)) == NULL) { socks5_seterr(SOCKS5_ERR_BAD_HOST); goto fail; } } /* try each server address in turn */ for (err = 0, sai = sais; sai != NULL; sai = sai->ai_next) { /* open socket */ if ((sd = socket(sai->ai_family, SOCK_STREAM, 0)) < 0) goto syserr; /* attempt to bind to client address */ for (err = 0, cai = cais; cai != NULL; cai = cai->ai_next) { if (cai->ai_family != sai->ai_family) continue; if ((err = bind(sd, cai->ai_addr, cai->ai_addrlen)) == 0) break; } if (err != 0) { if (verbose) fetch_info("failed to bind to %s", bindaddr); goto syserr; } /* attempt to connect to server address */ if ((err = connect(sd, sai->ai_addr, sai->ai_addrlen)) == 0) break; /* clean up before next attempt */ close(sd); sd = -1; } if (err != 0) { if (verbose && sockshost == NULL) { fetch_info("failed to connect to %s:%d", host, port); goto syserr; } else if (sockshost != NULL) { if (verbose) fetch_info( "failed to connect to SOCKS5 server %s:%d", sockshost, socksport); socks5_seterr(SOCKS5_ERR_CONN_REFUSED); goto fail; } goto syserr; } if ((conn = fetch_reopen(sd)) == NULL) goto syserr; if (sockshost) if (!fetch_socks5_init(conn, host, port, verbose)) goto fail; free(sockshost); if (cais != NULL) freeaddrinfo(cais); if (sais != NULL) freeaddrinfo(sais); return (conn); syserr: fetch_syserr(); fail: free(sockshost); /* Fully close if it was opened; otherwise just don't leak the fd. */ if (conn != NULL) fetch_close(conn); else if (sd >= 0) close(sd); if (cais != NULL) freeaddrinfo(cais); if (sais != NULL) freeaddrinfo(sais); return (NULL); } #ifdef WITH_SSL /* * Convert characters A-Z to lowercase (intentionally avoid any locale * specific conversions). */ static char fetch_ssl_tolower(char in) { if (in >= 'A' && in <= 'Z') return (in + 32); else return (in); } /* * isalpha implementation that intentionally avoids any locale specific * conversions. */ static int fetch_ssl_isalpha(char in) { return ((in >= 'A' && in <= 'Z') || (in >= 'a' && in <= 'z')); } /* * Check if passed hostnames a and b are equal. */ static int fetch_ssl_hname_equal(const char *a, size_t alen, const char *b, size_t blen) { size_t i; if (alen != blen) return (0); for (i = 0; i < alen; ++i) { if (fetch_ssl_tolower(a[i]) != fetch_ssl_tolower(b[i])) return (0); } return (1); } /* * Check if domain label is traditional, meaning that only A-Z, a-z, 0-9 * and '-' (hyphen) are allowed. Hyphens have to be surrounded by alpha- * numeric characters. Double hyphens (like they're found in IDN a-labels * 'xn--') are not allowed. Empty labels are invalid. */ static int fetch_ssl_is_trad_domain_label(const char *l, size_t len, int wcok) { size_t i; if (!len || l[0] == '-' || l[len-1] == '-') return (0); for (i = 0; i < len; ++i) { if (!isdigit(l[i]) && !fetch_ssl_isalpha(l[i]) && !(l[i] == '*' && wcok) && !(l[i] == '-' && l[i - 1] != '-')) return (0); } return (1); } /* * Check if host name consists only of numbers. This might indicate an IP * address, which is not a good idea for CN wildcard comparison. */ static int fetch_ssl_hname_is_only_numbers(const char *hostname, size_t len) { size_t i; for (i = 0; i < len; ++i) { if (!((hostname[i] >= '0' && hostname[i] <= '9') || hostname[i] == '.')) return (0); } return (1); } /* * Check if the host name h passed matches the pattern passed in m which * is usually part of subjectAltName or CN of a certificate presented to * the client. This includes wildcard matching. The algorithm is based on * RFC6125, sections 6.4.3 and 7.2, which clarifies RFC2818 and RFC3280. */ static int fetch_ssl_hname_match(const char *h, size_t hlen, const char *m, size_t mlen) { int delta, hdotidx, mdot1idx, wcidx; const char *hdot, *mdot1, *mdot2; const char *wc; /* wildcard */ if (!(h && *h && m && *m)) return (0); if ((wc = strnstr(m, "*", mlen)) == NULL) return (fetch_ssl_hname_equal(h, hlen, m, mlen)); wcidx = wc - m; /* hostname should not be just dots and numbers */ if (fetch_ssl_hname_is_only_numbers(h, hlen)) return (0); /* only one wildcard allowed in pattern */ if (strnstr(wc + 1, "*", mlen - wcidx - 1) != NULL) return (0); /* * there must be at least two more domain labels and * wildcard has to be in the leftmost label (RFC6125) */ mdot1 = strnstr(m, ".", mlen); if (mdot1 == NULL || mdot1 < wc || (mlen - (mdot1 - m)) < 4) return (0); mdot1idx = mdot1 - m; mdot2 = strnstr(mdot1 + 1, ".", mlen - mdot1idx - 1); if (mdot2 == NULL || (mlen - (mdot2 - m)) < 2) return (0); /* hostname must contain a dot and not be the 1st char */ hdot = strnstr(h, ".", hlen); if (hdot == NULL || hdot == h) return (0); hdotidx = hdot - h; /* * host part of hostname must be at least as long as * pattern it's supposed to match */ if (hdotidx < mdot1idx) return (0); /* * don't allow wildcards in non-traditional domain names * (IDN, A-label, U-label...) */ if (!fetch_ssl_is_trad_domain_label(h, hdotidx, 0) || !fetch_ssl_is_trad_domain_label(m, mdot1idx, 1)) return (0); /* match domain part (part after first dot) */ if (!fetch_ssl_hname_equal(hdot, hlen - hdotidx, mdot1, mlen - mdot1idx)) return (0); /* match part left of wildcard */ if (!fetch_ssl_hname_equal(h, wcidx, m, wcidx)) return (0); /* match part right of wildcard */ delta = mdot1idx - wcidx - 1; if (!fetch_ssl_hname_equal(hdot - delta, delta, mdot1 - delta, delta)) return (0); /* all tests succeeded, it's a match */ return (1); } /* * Get numeric host address info - returns NULL if host was not an IP * address. The caller is responsible for deallocation using * freeaddrinfo(3). */ static struct addrinfo * fetch_ssl_get_numeric_addrinfo(const char *hostname, size_t len) { struct addrinfo hints, *res; char *host; host = (char *)malloc(len + 1); memcpy(host, hostname, len); host[len] = '\0'; memset(&hints, 0, sizeof(hints)); hints.ai_family = PF_UNSPEC; hints.ai_socktype = SOCK_STREAM; hints.ai_protocol = 0; hints.ai_flags = AI_NUMERICHOST; /* port is not relevant for this purpose */ if (getaddrinfo(host, "443", &hints, &res) != 0) res = NULL; free(host); return res; } /* * Compare ip address in addrinfo with address passes. */ static int fetch_ssl_ipaddr_match_bin(const struct addrinfo *lhost, const char *rhost, size_t rhostlen) { const void *left; if (lhost->ai_family == AF_INET && rhostlen == 4) { left = (void *)&((struct sockaddr_in*)(void *) lhost->ai_addr)->sin_addr.s_addr; #ifdef INET6 } else if (lhost->ai_family == AF_INET6 && rhostlen == 16) { left = (void *)&((struct sockaddr_in6 *)(void *) lhost->ai_addr)->sin6_addr; #endif } else return (0); return (!memcmp(left, (const void *)rhost, rhostlen) ? 1 : 0); } /* * Compare ip address in addrinfo with host passed. If host is not an IP * address, comparison will fail. */ static int fetch_ssl_ipaddr_match(const struct addrinfo *laddr, const char *r, size_t rlen) { struct addrinfo *raddr; int ret; char *rip; ret = 0; if ((raddr = fetch_ssl_get_numeric_addrinfo(r, rlen)) == NULL) return 0; /* not a numeric host */ if (laddr->ai_family == raddr->ai_family) { if (laddr->ai_family == AF_INET) { rip = (char *)&((struct sockaddr_in *)(void *) raddr->ai_addr)->sin_addr.s_addr; ret = fetch_ssl_ipaddr_match_bin(laddr, rip, 4); #ifdef INET6 } else if (laddr->ai_family == AF_INET6) { rip = (char *)&((struct sockaddr_in6 *)(void *) raddr->ai_addr)->sin6_addr; ret = fetch_ssl_ipaddr_match_bin(laddr, rip, 16); #endif } } freeaddrinfo(raddr); return (ret); } /* * Verify server certificate by subjectAltName. */ static int fetch_ssl_verify_altname(STACK_OF(GENERAL_NAME) *altnames, const char *host, struct addrinfo *ip) { const GENERAL_NAME *name; size_t nslen; int i; const char *ns; for (i = 0; i < sk_GENERAL_NAME_num(altnames); ++i) { name = sk_GENERAL_NAME_value(altnames, i); ns = (const char *)ASN1_STRING_get0_data(name->d.ia5); nslen = (size_t)ASN1_STRING_length(name->d.ia5); if (name->type == GEN_DNS && ip == NULL && fetch_ssl_hname_match(host, strlen(host), ns, nslen)) return (1); else if (name->type == GEN_IPADD && ip != NULL && fetch_ssl_ipaddr_match_bin(ip, ns, nslen)) return (1); } return (0); } /* * Verify server certificate by CN. */ static int fetch_ssl_verify_cn(X509_NAME *subject, const char *host, struct addrinfo *ip) { ASN1_STRING *namedata; X509_NAME_ENTRY *nameentry; int cnlen, lastpos, loc, ret; unsigned char *cn; ret = 0; lastpos = -1; loc = -1; cn = NULL; /* get most specific CN (last entry in list) and compare */ while ((lastpos = X509_NAME_get_index_by_NID(subject, NID_commonName, lastpos)) != -1) loc = lastpos; if (loc > -1) { nameentry = X509_NAME_get_entry(subject, loc); namedata = X509_NAME_ENTRY_get_data(nameentry); cnlen = ASN1_STRING_to_UTF8(&cn, namedata); if (ip == NULL && fetch_ssl_hname_match(host, strlen(host), cn, cnlen)) ret = 1; else if (ip != NULL && fetch_ssl_ipaddr_match(ip, cn, cnlen)) ret = 1; OPENSSL_free(cn); } return (ret); } /* * Verify that server certificate subjectAltName/CN matches * hostname. First check, if there are alternative subject names. If yes, * those have to match. Only if those don't exist it falls back to * checking the subject's CN. */ static int fetch_ssl_verify_hname(X509 *cert, const char *host) { struct addrinfo *ip; STACK_OF(GENERAL_NAME) *altnames; X509_NAME *subject; int ret; ret = 0; ip = fetch_ssl_get_numeric_addrinfo(host, strlen(host)); altnames = X509_get_ext_d2i(cert, NID_subject_alt_name, NULL, NULL); if (altnames != NULL) { ret = fetch_ssl_verify_altname(altnames, host, ip); } else { subject = X509_get_subject_name(cert); if (subject != NULL) ret = fetch_ssl_verify_cn(subject, host, ip); } if (ip != NULL) freeaddrinfo(ip); if (altnames != NULL) GENERAL_NAMES_free(altnames); return (ret); } /* * Configure transport security layer based on environment. */ static void fetch_ssl_setup_transport_layer(SSL_CTX *ctx, int verbose) { long ssl_ctx_options; ssl_ctx_options = SSL_OP_ALL | SSL_OP_NO_SSLv3 | SSL_OP_NO_TICKET; if (getenv("SSL_NO_TLS1") != NULL) ssl_ctx_options |= SSL_OP_NO_TLSv1; if (getenv("SSL_NO_TLS1_1") != NULL) ssl_ctx_options |= SSL_OP_NO_TLSv1_1; if (getenv("SSL_NO_TLS1_2") != NULL) ssl_ctx_options |= SSL_OP_NO_TLSv1_2; if (verbose) fetch_info("SSL options: %lx", ssl_ctx_options); SSL_CTX_set_options(ctx, ssl_ctx_options); } /* * Configure peer verification based on environment. */ #define LOCAL_CERT_FILE _PATH_LOCALBASE "/etc/ssl/cert.pem" #define BASE_CERT_FILE "/etc/ssl/cert.pem" static int fetch_ssl_setup_peer_verification(SSL_CTX *ctx, int verbose) { X509_LOOKUP *crl_lookup; X509_STORE *crl_store; const char *ca_cert_file, *ca_cert_path, *crl_file; if (getenv("SSL_NO_VERIFY_PEER") == NULL) { ca_cert_file = getenv("SSL_CA_CERT_FILE"); if (ca_cert_file == NULL && access(LOCAL_CERT_FILE, R_OK) == 0) ca_cert_file = LOCAL_CERT_FILE; if (ca_cert_file == NULL && access(BASE_CERT_FILE, R_OK) == 0) ca_cert_file = BASE_CERT_FILE; ca_cert_path = getenv("SSL_CA_CERT_PATH"); if (verbose) { fetch_info("Peer verification enabled"); if (ca_cert_file != NULL) fetch_info("Using CA cert file: %s", ca_cert_file); if (ca_cert_path != NULL) fetch_info("Using CA cert path: %s", ca_cert_path); if (ca_cert_file == NULL && ca_cert_path == NULL) fetch_info("Using OpenSSL default " "CA cert file and path"); } SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER, fetch_ssl_cb_verify_crt); if (ca_cert_file != NULL || ca_cert_path != NULL) SSL_CTX_load_verify_locations(ctx, ca_cert_file, ca_cert_path); else SSL_CTX_set_default_verify_paths(ctx); if ((crl_file = getenv("SSL_CRL_FILE")) != NULL) { if (verbose) fetch_info("Using CRL file: %s", crl_file); crl_store = SSL_CTX_get_cert_store(ctx); crl_lookup = X509_STORE_add_lookup(crl_store, X509_LOOKUP_file()); if (crl_lookup == NULL || !X509_load_crl_file(crl_lookup, crl_file, X509_FILETYPE_PEM)) { fprintf(stderr, "Could not load CRL file %s\n", crl_file); return (0); } X509_STORE_set_flags(crl_store, X509_V_FLAG_CRL_CHECK | X509_V_FLAG_CRL_CHECK_ALL); } } return (1); } /* * Configure client certificate based on environment. */ static int fetch_ssl_setup_client_certificate(SSL_CTX *ctx, int verbose) { const char *client_cert_file, *client_key_file; if ((client_cert_file = getenv("SSL_CLIENT_CERT_FILE")) != NULL) { client_key_file = getenv("SSL_CLIENT_KEY_FILE") != NULL ? getenv("SSL_CLIENT_KEY_FILE") : client_cert_file; if (verbose) { fetch_info("Using client cert file: %s", client_cert_file); fetch_info("Using client key file: %s", client_key_file); } if (SSL_CTX_use_certificate_chain_file(ctx, client_cert_file) != 1) { fprintf(stderr, "Could not load client certificate %s\n", client_cert_file); return (0); } if (SSL_CTX_use_PrivateKey_file(ctx, client_key_file, SSL_FILETYPE_PEM) != 1) { fprintf(stderr, "Could not load client key %s\n", client_key_file); return (0); } } return (1); } /* * Callback for SSL certificate verification, this is called on server * cert verification. It takes no decision, but informs the user in case * verification failed. */ int fetch_ssl_cb_verify_crt(int verified, X509_STORE_CTX *ctx) { X509 *crt; X509_NAME *name; char *str; str = NULL; if (!verified) { if ((crt = X509_STORE_CTX_get_current_cert(ctx)) != NULL && (name = X509_get_subject_name(crt)) != NULL) str = X509_NAME_oneline(name, 0, 0); fprintf(stderr, "Certificate verification failed for %s\n", str != NULL ? str : "no relevant certificate"); OPENSSL_free(str); } return (verified); } #endif /* * Enable SSL on a connection. */ int fetch_ssl(conn_t *conn, const struct url *URL, int verbose) { #ifdef WITH_SSL int ret, ssl_err; X509_NAME *name; char *str; conn->ssl_meth = SSLv23_client_method(); conn->ssl_ctx = SSL_CTX_new(conn->ssl_meth); SSL_CTX_set_mode(conn->ssl_ctx, SSL_MODE_AUTO_RETRY); fetch_ssl_setup_transport_layer(conn->ssl_ctx, verbose); if (!fetch_ssl_setup_peer_verification(conn->ssl_ctx, verbose)) return (-1); if (!fetch_ssl_setup_client_certificate(conn->ssl_ctx, verbose)) return (-1); conn->ssl = SSL_new(conn->ssl_ctx); if (conn->ssl == NULL) { fprintf(stderr, "SSL context creation failed\n"); return (-1); } SSL_set_fd(conn->ssl, conn->sd); #if !defined(OPENSSL_NO_TLSEXT) if (!SSL_set_tlsext_host_name(conn->ssl, __DECONST(struct url *, URL)->host)) { fprintf(stderr, "TLS server name indication extension failed for host %s\n", URL->host); return (-1); } #endif while ((ret = SSL_connect(conn->ssl)) == -1) { ssl_err = SSL_get_error(conn->ssl, ret); if (ssl_err != SSL_ERROR_WANT_READ && ssl_err != SSL_ERROR_WANT_WRITE) { ERR_print_errors_fp(stderr); return (-1); } } conn->ssl_cert = SSL_get_peer_certificate(conn->ssl); if (conn->ssl_cert == NULL) { fprintf(stderr, "No server SSL certificate\n"); return (-1); } if (getenv("SSL_NO_VERIFY_HOSTNAME") == NULL) { if (verbose) fetch_info("Verify hostname"); if (!fetch_ssl_verify_hname(conn->ssl_cert, URL->host)) { fprintf(stderr, "SSL certificate subject doesn't match host %s\n", URL->host); return (-1); } } if (verbose) { fetch_info("%s connection established using %s", SSL_get_version(conn->ssl), SSL_get_cipher(conn->ssl)); name = X509_get_subject_name(conn->ssl_cert); str = X509_NAME_oneline(name, 0, 0); fetch_info("Certificate subject: %s", str); OPENSSL_free(str); name = X509_get_issuer_name(conn->ssl_cert); str = X509_NAME_oneline(name, 0, 0); fetch_info("Certificate issuer: %s", str); OPENSSL_free(str); } return (0); #else (void)conn; (void)verbose; (void)URL; fprintf(stderr, "SSL support disabled\n"); return (-1); #endif } #define FETCH_READ_WAIT -2 #define FETCH_READ_ERROR -1 #define FETCH_READ_DONE 0 #ifdef WITH_SSL static ssize_t fetch_ssl_read(SSL *ssl, char *buf, size_t len) { ssize_t rlen; int ssl_err; rlen = SSL_read(ssl, buf, len); if (rlen < 0) { ssl_err = SSL_get_error(ssl, rlen); if (ssl_err == SSL_ERROR_WANT_READ || ssl_err == SSL_ERROR_WANT_WRITE) { return (FETCH_READ_WAIT); } else { ERR_print_errors_fp(stderr); return (FETCH_READ_ERROR); } } return (rlen); } #endif static ssize_t fetch_socket_read(int sd, char *buf, size_t len) { ssize_t rlen; rlen = read(sd, buf, len); if (rlen < 0) { if (errno == EAGAIN || (errno == EINTR && fetchRestartCalls)) return (FETCH_READ_WAIT); else return (FETCH_READ_ERROR); } return (rlen); } /* * Read a character from a connection w/ timeout */ ssize_t fetch_read(conn_t *conn, char *buf, size_t len) { struct timeval now, timeout, delta; struct pollfd pfd; ssize_t rlen; int deltams; if (fetchTimeout > 0) { gettimeofday(&timeout, NULL); timeout.tv_sec += fetchTimeout; } deltams = INFTIM; memset(&pfd, 0, sizeof pfd); pfd.fd = conn->sd; pfd.events = POLLIN | POLLERR; for (;;) { /* * The socket is non-blocking. Instead of the canonical * poll() -> read(), we do the following: * * 1) call read() or SSL_read(). * 2) if we received some data, return it. * 3) if an error occurred, return -1. * 4) if read() or SSL_read() signaled EOF, return. * 5) if we did not receive any data but we're not at EOF, * call poll(). * * In the SSL case, this is necessary because if we * receive a close notification, we have to call * SSL_read() one additional time after we've read * everything we received. * * In the non-SSL case, it may improve performance (very * slightly) when reading small amounts of data. */ #ifdef WITH_SSL if (conn->ssl != NULL) rlen = fetch_ssl_read(conn->ssl, buf, len); else #endif rlen = fetch_socket_read(conn->sd, buf, len); if (rlen >= 0) { break; } else if (rlen == FETCH_READ_ERROR) { fetch_syserr(); return (-1); } // assert(rlen == FETCH_READ_WAIT); if (fetchTimeout > 0) { gettimeofday(&now, NULL); if (!timercmp(&timeout, &now, >)) { errno = ETIMEDOUT; fetch_syserr(); return (-1); } timersub(&timeout, &now, &delta); deltams = delta.tv_sec * 1000 + delta.tv_usec / 1000;; } errno = 0; pfd.revents = 0; if (poll(&pfd, 1, deltams) < 0) { if (errno == EINTR && fetchRestartCalls) continue; fetch_syserr(); return (-1); } } return (rlen); } /* * Read a line of text from a connection w/ timeout */ #define MIN_BUF_SIZE 1024 int fetch_getln(conn_t *conn) { char *tmp; size_t tmpsize; ssize_t len; char c; if (conn->buf == NULL) { if ((conn->buf = malloc(MIN_BUF_SIZE)) == NULL) { errno = ENOMEM; return (-1); } conn->bufsize = MIN_BUF_SIZE; } conn->buf[0] = '\0'; conn->buflen = 0; do { len = fetch_read(conn, &c, 1); if (len == -1) return (-1); if (len == 0) break; conn->buf[conn->buflen++] = c; if (conn->buflen == conn->bufsize) { tmp = conn->buf; tmpsize = conn->bufsize * 2 + 1; if ((tmp = realloc(tmp, tmpsize)) == NULL) { errno = ENOMEM; return (-1); } conn->buf = tmp; conn->bufsize = tmpsize; } } while (c != '\n'); conn->buf[conn->buflen] = '\0'; DEBUGF("<<< %s", conn->buf); return (0); } /* * Write to a connection w/ timeout */ ssize_t fetch_write(conn_t *conn, const char *buf, size_t len) { struct iovec iov; iov.iov_base = __DECONST(char *, buf); iov.iov_len = len; return fetch_writev(conn, &iov, 1); } /* * Write a vector to a connection w/ timeout * Note: can modify the iovec. */ ssize_t fetch_writev(conn_t *conn, struct iovec *iov, int iovcnt) { struct timeval now, timeout, delta; struct pollfd pfd; ssize_t wlen, total; int deltams; memset(&pfd, 0, sizeof pfd); if (fetchTimeout) { pfd.fd = conn->sd; pfd.events = POLLOUT | POLLERR; gettimeofday(&timeout, NULL); timeout.tv_sec += fetchTimeout; } total = 0; while (iovcnt > 0) { while (fetchTimeout && pfd.revents == 0) { gettimeofday(&now, NULL); if (!timercmp(&timeout, &now, >)) { errno = ETIMEDOUT; fetch_syserr(); return (-1); } timersub(&timeout, &now, &delta); deltams = delta.tv_sec * 1000 + delta.tv_usec / 1000; errno = 0; pfd.revents = 0; if (poll(&pfd, 1, deltams) < 0) { /* POSIX compliance */ if (errno == EAGAIN) continue; if (errno == EINTR && fetchRestartCalls) continue; return (-1); } } errno = 0; #ifdef WITH_SSL if (conn->ssl != NULL) wlen = SSL_write(conn->ssl, iov->iov_base, iov->iov_len); else #endif wlen = writev(conn->sd, iov, iovcnt); if (wlen == 0) { /* we consider a short write a failure */ /* XXX perhaps we shouldn't in the SSL case */ errno = EPIPE; fetch_syserr(); return (-1); } if (wlen < 0) { if (errno == EINTR && fetchRestartCalls) continue; return (-1); } total += wlen; while (iovcnt > 0 && wlen >= (ssize_t)iov->iov_len) { wlen -= iov->iov_len; iov++; iovcnt--; } if (iovcnt > 0) { iov->iov_len -= wlen; iov->iov_base = __DECONST(char *, iov->iov_base) + wlen; } } return (total); } /* * Write a line of text to a connection w/ timeout */ int fetch_putln(conn_t *conn, const char *str, size_t len) { struct iovec iov[2]; int ret; DEBUGF(">>> %s\n", str); iov[0].iov_base = __DECONST(char *, str); iov[0].iov_len = len; iov[1].iov_base = __DECONST(char *, ENDL); iov[1].iov_len = sizeof(ENDL); if (len == 0) ret = fetch_writev(conn, &iov[1], 1); else ret = fetch_writev(conn, iov, 2); if (ret == -1) return (-1); return (0); } /* * Close connection */ int fetch_close(conn_t *conn) { int ret; if (--conn->ref > 0) return (0); #ifdef WITH_SSL if (conn->ssl) { SSL_shutdown(conn->ssl); SSL_set_connect_state(conn->ssl); SSL_free(conn->ssl); conn->ssl = NULL; } if (conn->ssl_ctx) { SSL_CTX_free(conn->ssl_ctx); conn->ssl_ctx = NULL; } if (conn->ssl_cert) { X509_free(conn->ssl_cert); conn->ssl_cert = NULL; } #endif ret = close(conn->sd); free(conn->buf); free(conn); return (ret); } /*** Directory-related utility functions *************************************/ int fetch_add_entry(struct url_ent **p, int *size, int *len, const char *name, struct url_stat *us) { struct url_ent *tmp; if (*p == NULL) { *size = 0; *len = 0; } if (*len >= *size - 1) { tmp = reallocarray(*p, *size * 2 + 1, sizeof(**p)); if (tmp == NULL) { errno = ENOMEM; fetch_syserr(); return (-1); } *size = (*size * 2 + 1); *p = tmp; } tmp = *p + *len; snprintf(tmp->name, PATH_MAX, "%s", name); memcpy(&tmp->stat, us, sizeof(*us)); (*len)++; (++tmp)->name[0] = 0; return (0); } /*** Authentication-related utility functions ********************************/ static const char * fetch_read_word(FILE *f) { static char word[1024]; if (fscanf(f, " %1023s ", word) != 1) return (NULL); return (word); } static int fetch_netrc_open(void) { struct passwd *pwd; char fn[PATH_MAX]; const char *p; int fd, serrno; if ((p = getenv("NETRC")) != NULL) { DEBUGF("NETRC=%s\n", p); if (snprintf(fn, sizeof(fn), "%s", p) >= (int)sizeof(fn)) { fetch_info("$NETRC specifies a file name " "longer than PATH_MAX"); return (-1); } } else { if ((p = getenv("HOME")) == NULL) { if ((pwd = getpwuid(getuid())) == NULL || (p = pwd->pw_dir) == NULL) return (-1); } if (snprintf(fn, sizeof(fn), "%s/.netrc", p) >= (int)sizeof(fn)) return (-1); } if ((fd = open(fn, O_RDONLY)) < 0) { serrno = errno; DEBUGF("%s: %s\n", fn, strerror(serrno)); errno = serrno; } return (fd); } /* * Get authentication data for a URL from .netrc */ int fetch_netrc_auth(struct url *url) { const char *word; int serrno; FILE *f; if (url->netrcfd < 0) url->netrcfd = fetch_netrc_open(); if (url->netrcfd < 0) return (-1); if ((f = fdopen(url->netrcfd, "r")) == NULL) { serrno = errno; DEBUGF("fdopen(netrcfd): %s", strerror(errno)); close(url->netrcfd); url->netrcfd = -1; errno = serrno; return (-1); } rewind(f); DEBUGF("searching netrc for %s\n", url->host); while ((word = fetch_read_word(f)) != NULL) { if (strcmp(word, "default") == 0) { DEBUGF("using default netrc settings\n"); break; } if (strcmp(word, "machine") == 0 && (word = fetch_read_word(f)) != NULL && strcasecmp(word, url->host) == 0) { DEBUGF("using netrc settings for %s\n", word); break; } } if (word == NULL) goto ferr; while ((word = fetch_read_word(f)) != NULL) { if (strcmp(word, "login") == 0) { if ((word = fetch_read_word(f)) == NULL) goto ferr; if (snprintf(url->user, sizeof(url->user), "%s", word) > (int)sizeof(url->user)) { fetch_info("login name in .netrc is too long"); url->user[0] = '\0'; } } else if (strcmp(word, "password") == 0) { if ((word = fetch_read_word(f)) == NULL) goto ferr; if (snprintf(url->pwd, sizeof(url->pwd), "%s", word) > (int)sizeof(url->pwd)) { fetch_info("password in .netrc is too long"); url->pwd[0] = '\0'; } } else if (strcmp(word, "account") == 0) { if ((word = fetch_read_word(f)) == NULL) goto ferr; /* XXX not supported! */ } else { break; } } fclose(f); url->netrcfd = -1; return (0); ferr: serrno = errno; fclose(f); url->netrcfd = -1; errno = serrno; return (-1); } /* * The no_proxy environment variable specifies a set of domains for * which the proxy should not be consulted; the contents is a comma-, * or space-separated list of domain names. A single asterisk will * override all proxy variables and no transactions will be proxied * (for compatibility with lynx and curl, see the discussion at * ). */ int fetch_no_proxy_match(const char *host) { const char *no_proxy, *p, *q; size_t h_len, d_len; if ((no_proxy = getenv("NO_PROXY")) == NULL && (no_proxy = getenv("no_proxy")) == NULL) return (0); /* asterisk matches any hostname */ if (strcmp(no_proxy, "*") == 0) return (1); h_len = strlen(host); p = no_proxy; do { /* position p at the beginning of a domain suffix */ while (*p == ',' || isspace((unsigned char)*p)) p++; /* position q at the first separator character */ for (q = p; *q; ++q) if (*q == ',' || isspace((unsigned char)*q)) break; d_len = q - p; if (d_len > 0 && h_len >= d_len && strncasecmp(host + h_len - d_len, p, d_len) == 0) { /* domain name matches */ return (1); } p = q + 1; } while (*q); return (0); }