💾 Archived View for gmn.clttr.info › sources › cgmnlm.git › tree › src › client.c.txt captured on 2021-12-04 at 18:04:22.
⬅️ Previous capture (2021-12-03)
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#include <assert.h>
#include <errno.h>
#include <netdb.h>
#include <bearssl.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>
#include <gmni/certs.h>
#include <gmni/gmni.h>
#include <gmni/tofu.h>
#include <gmni/url.h>
#include <netinet/tcp.h>
static enum gemini_result
gemini_get_addrinfo(struct Curl_URL *uri, struct gemini_options *options,
struct gemini_response *resp, struct addrinfo **addr)
{
int port = 1965;
char *uport;
if (curl_url_get(uri, CURLUPART_PORT, &uport, 0) == CURLUE_OK) {
port = (int)strtol(uport, NULL, 10);
free(uport);
}
if (options && options->addr && options->addr->ai_family != AF_UNSPEC) {
*addr = options->addr;
} else {
struct addrinfo hints = {0};
if (options && options->hints) {
hints = *options->hints;
} else {
hints.ai_family = AF_UNSPEC;
}
hints.ai_socktype = SOCK_STREAM;
char pbuf[7];
snprintf(pbuf, sizeof(pbuf), "%d", port);
char *domain;
CURLUcode uc = curl_url_get(uri, CURLUPART_HOST, &domain, 0);
assert(uc == CURLUE_OK);
int r = getaddrinfo(domain, pbuf, &hints, addr);
free(domain);
if (r != 0) {
resp->status = r;
return GEMINI_ERR_RESOLVE;
}
}
return GEMINI_OK;
}
static enum gemini_result
gemini_connect(struct Curl_URL *uri, struct gemini_options *options,
struct gemini_response *resp, int *sfd)
{
struct addrinfo *addr;
enum gemini_result res = gemini_get_addrinfo(uri, options, resp, &addr);
if (res != GEMINI_OK) {
return res;
}
struct addrinfo *rp;
for (rp = addr; rp != NULL; rp = rp->ai_next) {
*sfd = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
if (*sfd == -1) {
continue;
}
int synRetries = 3;
setsockopt(*sfd, IPPROTO_TCP, TCP_SYNCNT, &synRetries, sizeof(synRetries));
if (connect(*sfd, rp->ai_addr, rp->ai_addrlen) != -1) {
break;
}
close(*sfd);
}
if (rp == NULL) {
resp->status = errno;
res = GEMINI_ERR_CONNECT;
return res;
}
if (!options || !options->addr) {
freeaddrinfo(addr);
}
return res;
}
#define GEMINI_META_MAXLEN 1024
#define GEMINI_STATUS_MAXLEN 2
static int
sock_read(void *ctx, unsigned char *buf, size_t len)
{
for (;;) {
ssize_t rlen;
rlen = read(*(int *)ctx, buf, len);
if (rlen <= 0) {
if (rlen < 0 && errno == EINTR) {
continue;
}
return -1;
}
return (int)rlen;
}
}
static int
sock_write(void *ctx, const unsigned char *buf, size_t len)
{
for (;;) {
ssize_t wlen;
wlen = write(*(int *)ctx, buf, len);
if (wlen <= 0) {
if (wlen < 0 && errno == EINTR) {
continue;
}
return -1;
}
return (int)wlen;
}
}
enum gemini_result
gemini_request(const char *url, struct gemini_options *options,
struct gemini_tofu *tofu, struct gemini_response *resp)
{
assert(url);
assert(resp);
memset(resp, 0, sizeof(*resp));
if (strlen(url) > 1024) {
return GEMINI_ERR_INVALID_URL;
}
struct Curl_URL *uri = curl_url();
if (!uri) {
return GEMINI_ERR_OOM;
}
enum gemini_result res = GEMINI_OK;
if (curl_url_set(uri, CURLUPART_URL, url, 0) != CURLUE_OK) {
res = GEMINI_ERR_INVALID_URL;
goto cleanup;
}
char *scheme, *host;
if (curl_url_get(uri, CURLUPART_SCHEME, &scheme, 0) != CURLUE_OK) {
res = GEMINI_ERR_INVALID_URL;
goto cleanup;
} else {
if (strcmp(scheme, "gemini") != 0) {
res = GEMINI_ERR_NOT_GEMINI;
free(scheme);
goto cleanup;
}
free(scheme);
}
if (curl_url_get(uri, CURLUPART_HOST, &host, 0) != CURLUE_OK) {
res = GEMINI_ERR_INVALID_URL;
free(host);
goto cleanup;
}
int r;
res = gemini_connect(uri, options, resp, &resp->fd);
if (res != GEMINI_OK) {
free(host);
goto cleanup;
}
// TODO: session reuse
resp->sc = &tofu->sc;
if (options->client_cert) {
struct gmni_client_certificate *cert = options->client_cert;
struct gmni_private_key *key = cert->key;
switch (key->type) {
case BR_KEYTYPE_RSA:
br_ssl_client_set_single_rsa(resp->sc,
cert->chain, cert->nchain, &key->rsa,
br_rsa_pkcs1_sign_get_default());
break;
case BR_KEYTYPE_EC:
br_ssl_client_set_single_ec(resp->sc,
cert->chain, cert->nchain, &key->ec,
BR_KEYTYPE_SIGN, 0,
br_ec_get_default(),
br_ecdsa_sign_asn1_get_default());
break;
}
} else {
br_ssl_client_set_client_certificate(resp->sc,
NULL);
}
br_ssl_client_reset(resp->sc, host, 0);
br_sslio_init(&resp->body, &resp->sc->eng,
sock_read, &resp->fd, sock_write, &resp->fd);
char req[1024 + 3];
r = snprintf(req, sizeof(req), "%s\r\n", url);
assert(r > 0);
br_sslio_write_all(&resp->body, req, r);
br_sslio_flush(&resp->body);
// The SSL engine maintains an internal buffer, so this shouldn't be as
// inefficient as it looks. It's necessary to do this one byte at a time
// to avoid consuming any of the response body buffer.
char buf[GEMINI_META_MAXLEN
+ GEMINI_STATUS_MAXLEN
+ 2 /* CRLF */ + 1 /* NUL */];
memset(buf, 0, sizeof(buf));
size_t l;
for (l = 0; l < 2 || memcmp(&buf[l-2], "\r\n", 2) != 0; ++l) {
r = br_sslio_read(&resp->body, &buf[l], 1);
if (r < 0) {
break;
}
}
int err = br_ssl_engine_last_error(&resp->sc->eng);
if (err != 0) {
// TODO: Bubble this up properly
fprintf(stderr, "SSL error %d\n", err);
goto ssl_error;
}
if (l < 3 || strcmp(&buf[l-2], "\r\n") != 0) {
fprintf(stderr, "invalid line '%s'\n", buf);
res = GEMINI_ERR_PROTOCOL;
goto cleanup;
}
char *endptr;
resp->status = (enum gemini_status)strtol(buf, &endptr, 10);
if (*endptr != ' ' || resp->status < 10 || (int)resp->status >= 70) {
fprintf(stderr, "invalid status\n");
res = GEMINI_ERR_PROTOCOL;
goto cleanup;
}
resp->meta = calloc(l - 5 /* 2 digits, space, and CRLF */ + 1 /* NUL */, 1);
strncpy(resp->meta, &endptr[1], l - 5);
resp->meta[l - 5] = '\0';
cleanup:
curl_url_cleanup(uri);
return res;
ssl_error:
res = GEMINI_ERR_SSL;
resp->status = r;
goto cleanup;
}
void
gemini_response_finish(struct gemini_response *resp)
{
if (!resp) {
return;
}
if (resp->fd != -1) {
close(resp->fd);
resp->fd = -1;
}
free(resp->meta);
if (resp->sc) {
br_sslio_close(&resp->body);
}
resp->sc = NULL;
resp->meta = NULL;
}
const char *
gemini_strerr(enum gemini_result r, struct gemini_response *resp)
{
switch (r) {
case GEMINI_OK:
return "OK";
case GEMINI_ERR_OOM:
return "Out of memory";
case GEMINI_ERR_INVALID_URL:
return "Invalid URL";
case GEMINI_ERR_NOT_GEMINI:
return "Not a gemini URL";
case GEMINI_ERR_RESOLVE:
return gai_strerror(resp->status);
case GEMINI_ERR_CONNECT:
return strerror(errno);
case GEMINI_ERR_SSL:
// TODO: more specific
return "SSL error";
case GEMINI_ERR_SSL_VERIFY:
// TODO: more specific
return "X.509 certificate not trusted";
case GEMINI_ERR_IO:
return "I/O error";
case GEMINI_ERR_PROTOCOL:
return "Protocol error";
}
assert(0);
}
char *
gemini_input_url(const char *url, const char *input)
{
char *new_url = NULL;
struct Curl_URL *uri = curl_url();
if (!uri) {
return NULL;
}
if (curl_url_set(uri, CURLUPART_URL, url, 0) != CURLUE_OK) {
goto cleanup;
}
if (curl_url_set(uri, CURLUPART_QUERY, input, CURLU_URLENCODE) != CURLUE_OK) {
goto cleanup;
}
if (curl_url_get(uri, CURLUPART_URL, &new_url, 0) != CURLUE_OK) {
new_url = NULL;
goto cleanup;
}
cleanup:
curl_url_cleanup(uri);
return new_url;
}
enum gemini_status_class
gemini_response_class(enum gemini_status status)
{
return status / 10 * 10;
}