diff options
| -rw-r--r-- | .gitignore | 2 | ||||
| -rw-r--r-- | Makefile | 18 | ||||
| -rw-r--r-- | chat.c | 73 | ||||
| -rw-r--r-- | chat.h | 102 | ||||
| -rw-r--r-- | handle.c | 163 | ||||
| -rw-r--r-- | irc.c | 205 |
6 files changed, 563 insertions, 0 deletions
diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..ab80afd --- /dev/null +++ b/.gitignore @@ -0,0 +1,2 @@ +*.o +catgirl diff --git a/Makefile b/Makefile new file mode 100644 index 0000000..30bcf66 --- /dev/null +++ b/Makefile @@ -0,0 +1,18 @@ +LIBRESSL_PREFIX = /usr/local +CFLAGS += -I${LIBRESSL_PREFIX}/include +LDFLAGS += -L${LIBRESSL_PREFIX}/lib + +CFLAGS += -std=c11 -Wall -Wextra -Wpedantic +LDLIBS = -lcrypto -ltls + +OBJS += chat.o +OBJS += handle.o +OBJS += irc.o + +catgirl: ${OBJS} + ${CC} ${LDFLAGS} ${OBJS} ${LDLIBS} -o $@ + +${OBJS}: chat.h + +clean: + rm -f catgirl ${OBJS} diff --git a/chat.c b/chat.c new file mode 100644 index 0000000..89579c0 --- /dev/null +++ b/chat.c @@ -0,0 +1,73 @@ +/* Copyright (C) 2020 C. McEnroe <june@causal.agency> + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <https://www.gnu.org/licenses/>. + */ + +#include <err.h> +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> +#include <sysexits.h> +#include <unistd.h> + +#include "chat.h" + +struct Self self; + +int main(int argc, char *argv[]) { + bool insecure = false; + const char *host = NULL; + const char *port = "6697"; + const char *cert = NULL; + const char *priv = NULL; + + bool sasl = false; + const char *pass = NULL; + const char *nick = NULL; + const char *user = NULL; + const char *real = NULL; + + int opt; + while (0 < (opt = getopt(argc, argv, "!a:c:eh:j:k:n:p:r:u:w:"))) { + switch (opt) { + break; case '!': insecure = true; + break; case 'a': sasl = true; self.plain = optarg; + break; case 'c': cert = optarg; + break; case 'e': sasl = true; + break; case 'h': host = optarg; + break; case 'j': self.join = optarg; + break; case 'k': priv = optarg; + break; case 'n': nick = optarg; + break; case 'p': port = optarg; + break; case 'r': real = optarg; + break; case 'u': user = optarg; + break; case 'w': pass = optarg; + } + } + if (!host) errx(EX_USAGE, "host required"); + + if (!nick) nick = getenv("USER"); + if (!nick) errx(EX_CONFIG, "USER unset"); + if (!user) user = nick; + if (!real) real = nick; + + ircConfig(insecure, cert, priv); + + int irc = ircConnect(host, port); + if (pass) ircFormat("PASS :%s\r\n", pass); + if (sasl) ircFormat("CAP REQ :sasl\r\n"); + ircFormat("CAP LS\r\n"); + ircFormat("NICK :%s\r\n", nick); + ircFormat("USER %s 0 * :%s\r\n", user, real); +} diff --git a/chat.h b/chat.h new file mode 100644 index 0000000..bb8929b --- /dev/null +++ b/chat.h @@ -0,0 +1,102 @@ +/* Copyright (C) 2020 C. McEnroe <june@causal.agency> + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <https://www.gnu.org/licenses/>. + */ + +#include <stdbool.h> + +#define ARRAY_LEN(a) (sizeof(a) / sizeof(a[0])) +#define BIT(x) x##Bit, x = 1 << x##Bit, x##Bit_ = x##Bit + +typedef unsigned char byte; + +#define ENUM_CAP \ + X("sasl", CapSASL) \ + X("server-time", CapServerTime) \ + X("userhost-in-names", CapUserhostInNames) + +enum Cap { +#define X(name, id) BIT(id), + ENUM_CAP +#undef X +}; + +extern struct Self { + enum Cap caps; + char *plain; + char *nick; + const char *join; +} self; + +#define ENUM_TAG \ + X("time", TagTime) + +enum Tag { +#define X(name, id) id, + ENUM_TAG +#undef X + TagCap, +}; + +enum { ParamCap = 15 }; +struct Message { + char *tags[TagCap]; + char *nick; + char *user; + char *host; + char *cmd; + char *params[ParamCap]; +}; + +void ircConfig(bool insecure, const char *cert, const char *priv); +int ircConnect(const char *host, const char *port); +void ircRecv(void); +void ircSend(const char *ptr, size_t len); +void ircFormat(const char *format, ...) + __attribute__((format(printf, 1, 2))); + +void handle(struct Message msg); + +#define BASE64_SIZE(len) (1 + ((len) + 2) / 3 * 4) + +static const char Base64[64] = { + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/" +}; + +static inline void base64(char *dst, const byte *src, size_t len) { + size_t i = 0; + while (len > 2) { + dst[i++] = Base64[0x3F & (src[0] >> 2)]; + dst[i++] = Base64[0x3F & (src[0] << 4 | src[1] >> 4)]; + dst[i++] = Base64[0x3F & (src[1] << 2 | src[2] >> 6)]; + dst[i++] = Base64[0x3F & src[2]]; + src += 3; + len -= 3; + } + if (len) { + dst[i++] = Base64[0x3F & (src[0] >> 2)]; + if (len > 1) { + dst[i++] = Base64[0x3F & (src[0] << 4 | src[1] >> 4)]; + dst[i++] = Base64[0x3F & (src[1] << 2)]; + } else { + dst[i++] = Base64[0x3F & (src[0] << 4)]; + dst[i++] = '='; + } + dst[i++] = '='; + } + dst[i] = '\0'; +} + +// Defined in libcrypto if missing from libc: +void explicit_bzero(void *b, size_t len); diff --git a/handle.c b/handle.c new file mode 100644 index 0000000..4084525 --- /dev/null +++ b/handle.c @@ -0,0 +1,163 @@ +/* Copyright (C) 2020 C. McEnroe <june@causal.agency> + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <https://www.gnu.org/licenses/>. + */ + +#include <err.h> +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sysexits.h> + +#include "chat.h" + +static const char *CapNames[] = { +#define X(name, id) [id] = name, + ENUM_CAP +#undef X +}; + +static enum Cap capParse(const char *list) { + enum Cap caps = 0; + while (*list) { + enum Cap cap = 0; + size_t len = strcspn(list, " "); + for (size_t i = 0; i < ARRAY_LEN(CapNames); ++i) { + if (len != strlen(CapNames[i])) continue; + if (strncmp(list, CapNames[i], len)) continue; + cap = 1 << i; + break; + } + caps |= cap; + list += len; + if (*list) list++; + } + return caps; +} + +static const char *capList(enum Cap caps) { + static char buf[1024]; + buf[0] = '\0'; + for (size_t i = 0; i < ARRAY_LEN(CapNames); ++i) { + if (caps & (1 << i)) { + if (buf[0]) strlcat(buf, " ", sizeof(buf)); + strlcat(buf, CapNames[i], sizeof(buf)); + } + } + return buf; +} + +static void set(char **field, const char *value) { + free(*field); + *field = strdup(value); + if (!*field) err(EX_OSERR, "strdup"); +} + +typedef void Handler(struct Message *msg); + +static void require(const struct Message *msg, bool origin, size_t len) { + if (origin && !msg->nick) { + errx(EX_PROTOCOL, "%s missing origin", msg->cmd); + } + for (size_t i = 0; i < len; ++i) { + if (msg->params[i]) continue; + errx(EX_PROTOCOL, "%s missing parameter %zu", msg->cmd, 1 + i); + } +} + +static void handleCap(struct Message *msg) { + require(msg, false, 3); + enum Cap caps = capParse(msg->params[2]); + if (!strcmp(msg->params[1], "LS")) { + caps &= ~CapSASL; + ircFormat("CAP REQ :%s\r\n", capList(caps)); + } else if (!strcmp(msg->params[1], "ACK")) { + self.caps |= caps; + if (caps & CapSASL) { + ircFormat("AUTHENTICATE %s\r\n", (self.plain ? "PLAIN" : "EXTERNAL")); + } + if (!(self.caps & CapSASL)) ircFormat("CAP END\r\n"); + } else if (!strcmp(msg->params[1], "NAK")) { + errx(EX_CONFIG, "server does not support %s", msg->params[2]); + } +} + +static void handleAuthenticate(struct Message *msg) { + (void)msg; + if (!self.plain) { + ircFormat("AUTHENTICATE +\r\n"); + return; + } + + byte buf[299]; + size_t len = 1 + strlen(self.plain); + if (sizeof(buf) < len) errx(EX_CONFIG, "SASL PLAIN is too long"); + buf[0] = 0; + for (size_t i = 0; self.plain[i]; ++i) { + buf[1 + i] = (self.plain[i] == ':' ? 0 : self.plain[i]); + } + + char b64[BASE64_SIZE(sizeof(buf))]; + base64(b64, buf, len); + ircFormat("AUTHENTICATE "); + ircSend(b64, BASE64_SIZE(len)); + ircFormat("\r\n"); + + explicit_bzero(b64, sizeof(b64)); + explicit_bzero(buf, sizeof(buf)); + explicit_bzero(self.plain, strlen(self.plain)); +} + +static void handleReplyLoggedIn(struct Message *msg) { + (void)msg; + ircFormat("CAP END\r\n"); +} + +static void handleErrorSASLFail(struct Message *msg) { + require(msg, false, 2); + errx(EX_CONFIG, "%s", msg->params[1]); +} + +static void handleReplyWelcome(struct Message *msg) { + require(msg, false, 1); + set(&self.nick, msg->params[0]); + if (self.join) ircFormat("JOIN :%s\r\n", self.join); +} + +static const struct Handler { + const char *cmd; + Handler *fn; +} Handlers[] = { + { "001", handleReplyWelcome }, + { "900", handleReplyLoggedIn }, + { "904", handleErrorSASLFail }, + { "905", handleErrorSASLFail }, + { "906", handleErrorSASLFail }, + { "AUTHENTICATE", handleAuthenticate }, + { "CAP", handleCap }, +}; + +static int compar(const void *cmd, const void *_handler) { + const struct Handler *handler = _handler; + return strcmp(cmd, handler->cmd); +} + +void handle(struct Message msg) { + if (!msg.cmd) return; + const struct Handler *handler = bsearch( + msg.cmd, Handlers, ARRAY_LEN(Handlers), sizeof(*handler), compar + ); + if (handler) handler->fn(&msg); +} diff --git a/irc.c b/irc.c new file mode 100644 index 0000000..c1c0e7a --- /dev/null +++ b/irc.c @@ -0,0 +1,205 @@ +/* Copyright (C) 2020 C. McEnroe <june@causal.agency> + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <https://www.gnu.org/licenses/>. + */ + +#include <assert.h> +#include <err.h> +#include <netdb.h> +#include <netinet/in.h> +#include <stdarg.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/socket.h> +#include <sysexits.h> +#include <tls.h> +#include <unistd.h> + +#include "chat.h" + +struct tls *client; + +void ircConfig(bool insecure, const char *cert, const char *priv) { + struct tls_config *config = tls_config_new(); + if (!config) errx(EX_SOFTWARE, "tls_config_new"); + + int error = tls_config_set_ciphers(config, "compat"); + if (error) { + errx( + EX_SOFTWARE, "tls_config_set_ciphers: %s", + tls_config_error(config) + ); + } + + if (insecure) { + tls_config_insecure_noverifycert(config); + tls_config_insecure_noverifyname(config); + } + + if (cert) { + error = tls_config_set_keypair_file(config, cert, (priv ? priv : cert)); + if (error) { + errx( + EX_SOFTWARE, "tls_config_set_keypair_file: %s", + tls_config_error(config) + ); + } + } + + client = tls_client(); + if (!client) errx(EX_SOFTWARE, "tls_client"); + + error = tls_configure(client, config); + if (error) errx(EX_SOFTWARE, "tls_configure: %s", tls_error(client)); + tls_config_free(config); +} + +int ircConnect(const char *host, const char *port) { + assert(client); + + struct addrinfo *head; + struct addrinfo hints = { + .ai_family = AF_UNSPEC, + .ai_socktype = SOCK_STREAM, + .ai_protocol = IPPROTO_TCP, + }; + int error = getaddrinfo(host, port, &hints, &head); + if (error) errx(EX_NOHOST, "%s:%s: %s", host, port, gai_strerror(error)); + + int sock = -1; + for (struct addrinfo *ai = head; ai; ai = ai->ai_next) { + sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); + if (sock < 0) err(EX_OSERR, "socket"); + + error = connect(sock, ai->ai_addr, ai->ai_addrlen); + if (!error) break; + + close(sock); + sock = -1; + } + if (sock < 0) err(EX_UNAVAILABLE, "%s:%s", host, port); + freeaddrinfo(head); + + error = tls_connect_socket(client, sock, host); + if (error) errx(EX_PROTOCOL, "tls_connect: %s", tls_error(client)); + + error = tls_handshake(client); + if (error) errx(EX_PROTOCOL, "tls_handshake: %s", tls_error(client)); + + return sock; +} + +void ircSend(const char *ptr, size_t len) { + assert(client); + while (len) { + ssize_t ret = tls_write(client, ptr, len); + if (ret == TLS_WANT_POLLIN || ret == TLS_WANT_POLLOUT) continue; + if (ret < 0) errx(EX_IOERR, "tls_write: %s", tls_error(client)); + ptr += ret; + len -= ret; + } +} + +void ircFormat(const char *format, ...) { + char buf[1024]; + va_list ap; + va_start(ap, format); + int len = vsnprintf(buf, sizeof(buf), format, ap); + va_end(ap); + assert((size_t)len < sizeof(buf)); + ircSend(buf, len); +} + +static const char *TagNames[TagCap] = { +#define X(name, id) [id] = name, + ENUM_TAG +#undef X +}; + +static void unescape(char *tag) { + for (;;) { + tag = strchr(tag, '\\'); + if (!tag) break; + switch (tag[1]) { + break; case ':': tag[1] = ';'; + break; case 's': tag[1] = ' '; + break; case 'r': tag[1] = '\r'; + break; case 'n': tag[1] = '\n'; + } + memmove(tag, &tag[1], strlen(&tag[1]) + 1); + if (tag[0]) tag = &tag[1]; + } +} + +static struct Message parse(char *line) { + struct Message msg = { .cmd = NULL }; + + if (line[0] == '@') { + char *tags = 1 + strsep(&line, " "); + while (tags) { + char *tag = strsep(&tags, ";"); + char *key = strsep(&tag, "="); + for (size_t i = 0; i < TagCap; ++i) { + if (strcmp(key, TagNames[i])) continue; + unescape(tag); + msg.tags[i] = tag; + break; + } + } + } + + if (line[0] == ':') { + char *origin = 1 + strsep(&line, " "); + msg.nick = strsep(&origin, "!"); + msg.user = strsep(&origin, "@"); + msg.host = origin; + } + + msg.cmd = strsep(&line, " "); + for (size_t i = 0; line && i < ParamCap; ++i) { + if (line[0] == ':') { + msg.params[i] = &line[1]; + break; + } + msg.params[i] = strsep(&line, " "); + } + + return msg; +} + +void ircRecv(void) { + static char buf[8191 + 512]; + static size_t len = 0; + + assert(client); + ssize_t ret = tls_read(client, &buf[len], sizeof(buf) - len); + if (ret == TLS_WANT_POLLIN || ret == TLS_WANT_POLLOUT) return; + if (ret < 0) errx(EX_IOERR, "tls_read: %s", tls_error(client)); + if (!ret) errx(EX_PROTOCOL, "server closed connection"); + len += ret; + + char *crlf; + char *line = buf; + for (;;) { + crlf = memmem(line, &buf[len] - line, "\r\n", 2); + if (!crlf) break; + *crlf = '\0'; + handle(parse(line)); + line = crlf + 2; + } + + len -= line - buf; + memmove(buf, line, len); +} |