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freebsd-dev/lib/libfetch/common.c
Dag-Erling Smørgrav 08a49957b3 r308996 broke IP literals by assuming that a colon could only occur as 
a separator between host and port, and using strchr() to search for it.
Rewrite fetch_resolve() so it handles bracketed literals correctly, and
remove similar code elsewhere to avoid passing unbracketed literals to
fetch_resolve().  Remove #ifdef INET6 so we still parse IP literals
correctly even if we do not have the ability to connect to them.

While there, fix an off-by-one error which caused HTTP 400 errors to be
misinterpreted as redirects.

PR:		217723
MFC after:	1 week
Reported by:	bapt, bz, cem, ngie
2017-03-17 14:18:52 +00:00

1495 lines
34 KiB
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/*-
* Copyright (c) 1998-2016 Dag-Erling Smørgrav
* Copyright (c) 2013 Michael Gmelin <freebsd@grem.de>
* 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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/uio.h>
#include <netinet/in.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <netdb.h>
#include <poll.h>
#include <pwd.h>
#include <stdarg.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#ifdef WITH_SSL
#include <openssl/x509v3.h>
#endif
#include "fetch.h"
#include "common.h"
/*** Local data **************************************************************/
/*
* Error messages for resolver errors
*/
static struct fetcherr netdb_errlist[] = {
#ifdef EAI_NODATA
{ EAI_NODATA, FETCH_RESOLV, "Host not found" },
#endif
{ EAI_AGAIN, FETCH_TEMP, "Transient resolver failure" },
{ EAI_FAIL, FETCH_RESOLV, "Non-recoverable resolver failure" },
{ EAI_NONAME, FETCH_RESOLV, "No address record" },
{ -1, FETCH_UNKNOWN, "Unknown resolver error" }
};
/* 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 (strcasecmp(scheme, SCHEME_FTP) == 0)
return (FTP_DEFAULT_PORT);
if (strcasecmp(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 (strcasecmp(scheme, SCHEME_FTP) == 0)
return (FTP_DEFAULT_PROXY_PORT);
if (strcasecmp(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;
} 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);
}
/*
* 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;
DEBUG(fprintf(stderr, "---> %s:%d\n", host, port));
/* 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;
}
/* 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)
fetch_info("failed to connect to %s:%d", host, port);
goto syserr;
}
if ((conn = fetch_reopen(sd)) == NULL)
goto syserr;
if (cais != NULL)
freeaddrinfo(cais);
if (sais != NULL)
freeaddrinfo(sais);
return (conn);
syserr:
fetch_syserr();
goto fail;
fail:
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) {
#if OPENSSL_VERSION_NUMBER < 0x10000000L
/*
* This is a workaround, since the following line causes
* alignment issues in clang:
* name = sk_GENERAL_NAME_value(altnames, i);
* OpenSSL explicitly warns not to use those macros
* directly, but there isn't much choice (and there
* shouldn't be any ill side effects)
*/
name = (GENERAL_NAME *)SKM_sk_value(void, altnames, i);
#else
name = sk_GENERAL_NAME_value(altnames, i);
#endif
ns = (const char *)ASN1_STRING_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_SSLv2 | SSL_OP_NO_TICKET;
if (getenv("SSL_ALLOW_SSL3") == NULL)
ssl_ctx_options |= SSL_OP_NO_SSLv3;
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 "/usr/local/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;
/* Init the SSL library and context */
if (!SSL_library_init()){
fprintf(stderr, "SSL library init failed\n");
return (-1);
}
SSL_load_error_strings();
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 OPENSSL_VERSION_NUMBER >= 0x0090806fL && !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;
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';
DEBUG(fprintf(stderr, "<<< %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;
DEBUG(fprintf(stderr, ">>> %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)
{
const char *p;
char fn[PATH_MAX];
if ((p = getenv("NETRC")) != NULL) {
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) {
struct passwd *pwd;
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);
}
return (open(fn, O_RDONLY));
}
/*
* Get authentication data for a URL from .netrc
*/
int
fetch_netrc_auth(struct url *url)
{
const char *word;
FILE *f;
if (url->netrcfd == -2)
url->netrcfd = fetch_netrc_open();
if (url->netrcfd < 0)
return (-1);
if ((f = fdopen(url->netrcfd, "r")) == NULL)
return (-1);
rewind(f);
while ((word = fetch_read_word(f)) != NULL) {
if (strcmp(word, "default") == 0) {
DEBUG(fetch_info("Using default .netrc settings"));
break;
}
if (strcmp(word, "machine") == 0 &&
(word = fetch_read_word(f)) != NULL &&
strcasecmp(word, url->host) == 0) {
DEBUG(fetch_info("Using .netrc settings for %s", 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);
return (0);
ferr:
fclose(f);
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
* <http://curl.haxx.se/mail/archive_pre_oct_99/0009.html>).
*/
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);
}
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