diff options
Diffstat (limited to 'tests')
| -rw-r--r-- | tests/smtp_check.c | 663 |
1 files changed, 663 insertions, 0 deletions
diff --git a/tests/smtp_check.c b/tests/smtp_check.c new file mode 100644 index 0000000..331f4a9 --- /dev/null +++ b/tests/smtp_check.c @@ -0,0 +1,663 @@ +#include <arpa/inet.h> +#include <errno.h> +#include <netinet/in.h> +#include <signal.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/socket.h> +#include <sys/wait.h> +#include <unistd.h> + +#include <openssl/ssl.h> + +#include "smtp.h" +#include "util.h" + +enum { + SRV_NOAUTH = 0, + SRV_AUTH_PLAIN, + SRV_AUTH_LOGIN, + SRV_RCPT_REJECT, + SRV_TLS, + SRV_STARTTLS +}; + +struct srv_result { + int saw_ehlo; + int saw_auth; + int saw_auth_plain; + int saw_auth_login; + int saw_starttls; + size_t data_len; +}; + +static int failures; + +static void check(int cond, const char *what) +{ + if (!cond) { + printf("FAIL %s\n", what); + failures++; + } else { + printf("ok %s\n", what); + } +} + +static int contains(const unsigned char *data, size_t len, const char *needle) +{ + size_t n = strlen(needle); + if (n > len) + return 0; + for (size_t i = 0; i + n <= len; i++) + if (memcmp(data + i, needle, n) == 0) + return 1; + return 0; +} + +static int count_occ(const unsigned char *data, size_t len, const char *needle) +{ + size_t n = strlen(needle); + int c = 0; + if (n == 0 || n > len) + return 0; + for (size_t i = 0; i + n <= len; i++) + if (memcmp(data + i, needle, n) == 0) + c++; + return c; +} + +static ssize_t read_full(int fd, void *buf, size_t n) +{ + unsigned char *p = buf; + size_t got = 0; + while (got < n) { + ssize_t r = read(fd, p + got, n - got); + if (r < 0) { + if (errno == EINTR) + continue; + return -1; + } + if (r == 0) + break; + got += (size_t)r; + } + return (ssize_t)got; +} + +static int write_full(int fd, const void *buf, size_t n) +{ + const unsigned char *p = buf; + size_t done = 0; + while (done < n) { + ssize_t w = write(fd, p + done, n - done); + if (w < 0) { + if (errno == EINTR) + continue; + return -1; + } + done += (size_t)w; + } + return 0; +} + +struct srv_io { + int fd; + SSL *ssl; + unsigned char buf[4096]; + size_t len; + size_t pos; +}; + +static int srv_write_all(struct srv_io *io, const char *s) +{ + size_t n = strlen(s); + size_t o = 0; + while (o < n) { + ssize_t w = io->ssl ? SSL_write(io->ssl, s + o, (int)(n - o)) + : write(io->fd, s + o, n - o); + if (w <= 0) + return -1; + o += (size_t)w; + } + return 0; +} + +static ssize_t srv_line(struct srv_io *io, char *out, size_t outsz) +{ + size_t o = 0; + for (;;) { + if (io->pos >= io->len) { + ssize_t n = io->ssl ? SSL_read(io->ssl, io->buf, (int)sizeof io->buf) + : read(io->fd, io->buf, sizeof io->buf); + if (n <= 0) + return -1; + io->len = (size_t)n; + io->pos = 0; + } + unsigned char ch = io->buf[io->pos++]; + if (ch == '\n') { + while (o > 0 && out[o - 1] == '\r') + o--; + out[o] = '\0'; + return (ssize_t)o; + } + if (o + 1 < outsz) + out[o++] = (char)ch; + } +} + +static void srv_tls_accept(struct srv_io *io) +{ + SSL_CTX *ctx = SSL_CTX_new(TLS_server_method()); + if (!ctx || + SSL_CTX_use_certificate_chain_file(ctx, + "tests/tls_test_cert.pem") != 1 || + SSL_CTX_use_PrivateKey_file(ctx, "tests/tls_test_key.pem", + SSL_FILETYPE_PEM) != 1) + _exit(1); + SSL *ssl = SSL_new(ctx); + if (!ssl || SSL_set_fd(ssl, io->fd) != 1 || SSL_accept(ssl) != 1) + _exit(1); + io->ssl = ssl; +} + +static void srv_ehlo(struct srv_io *io, int mode, int after_tls) +{ + srv_write_all(io, "250-test.local hello\r\n"); + if (mode == SRV_AUTH_PLAIN) + srv_write_all(io, "250-AUTH PLAIN LOGIN\r\n"); + else if (mode == SRV_AUTH_LOGIN) + srv_write_all(io, "250-AUTH LOGIN\r\n"); + if (mode == SRV_STARTTLS && !after_tls) + srv_write_all(io, "250-STARTTLS\r\n"); + srv_write_all(io, "250 SIZE 10485760\r\n"); +} + +static int plain_ok(const char *b64) +{ + static const unsigned char want[] = { 0, 'm', 'a', 'i', 'l', + 'e', 'r', 0, 's', '3', + 'c', 'r', 'e', 't' }; + unsigned char *raw = NULL; + size_t len = 0; + if (util_b64_decode(b64, strlen(b64), &raw, &len) != 0) { + if (getenv("SMTP_CHECK_DUMP")) + fprintf(stderr, "server: AUTH PLAIN decode failed [%s]\n", b64); + return 0; + } + int ok = len == sizeof want && memcmp(raw, want, len) == 0; + if (!ok && getenv("SMTP_CHECK_DUMP")) + fprintf(stderr, "server: AUTH PLAIN mismatch len=%zu [%s]\n", len, + b64); + free(raw); + return ok; +} + +static void server_main(int wfd, int mode) +{ + int sfd = socket(AF_INET, SOCK_STREAM | SOCK_CLOEXEC, 0); + if (sfd < 0) + _exit(1); + struct sockaddr_in sa; + memset(&sa, 0, sizeof sa); + sa.sin_family = AF_INET; + sa.sin_addr.s_addr = htonl(INADDR_LOOPBACK); + sa.sin_port = 0; + if (bind(sfd, (struct sockaddr *)&sa, sizeof sa) != 0 || + listen(sfd, 1) != 0) + _exit(1); + socklen_t slen = sizeof sa; + if (getsockname(sfd, (struct sockaddr *)&sa, &slen) != 0) + _exit(1); + int port = ntohs(sa.sin_port); + if (write_full(wfd, &port, sizeof port) != 0) + _exit(1); + int cfd = accept(sfd, NULL, NULL); + if (cfd < 0) + _exit(1); + close(sfd); + + struct srv_io io; + memset(&io, 0, sizeof io); + io.fd = cfd; + struct srv_result res; + memset(&res, 0, sizeof res); + struct buf data; + buf_init(&data); + + char *b64_user = util_b64((const unsigned char *)"mailer", 6); + char *b64_pass = util_b64((const unsigned char *)"s3cret", 6); + + if (mode == SRV_TLS) + srv_tls_accept(&io); + srv_write_all(&io, "220 test.local ESMTP\r\n"); + + int in_data = 0; + char line[2048]; + for (;;) { + ssize_t n = srv_line(&io, line, sizeof line); + if (n < 0) + break; + if (in_data) { + if (strcmp(line, ".") == 0) { + res.data_len = data.len; + in_data = 0; + if (srv_write_all(&io, "250 2.0.0 queued\r\n") != 0) + break; + continue; + } + const char *payload = line[0] == '.' ? line + 1 : line; + buf_append(&data, payload, strlen(payload)); + buf_append(&data, "\r\n", 2); + continue; + } + if (strncmp(line, "EHLO", 4) == 0) { + res.saw_ehlo++; + srv_ehlo(&io, mode, mode == SRV_TLS || io.ssl != NULL); + } else if (strcmp(line, "STARTTLS") == 0) { + res.saw_starttls = 1; + srv_write_all(&io, "220 2.0.0 ready\r\n"); + srv_tls_accept(&io); + } else if (strncmp(line, "AUTH PLAIN", 10) == 0) { + res.saw_auth = 1; + res.saw_auth_plain = 1; + const char *arg = line + 10; + while (*arg == ' ') + arg++; + srv_write_all(&io, plain_ok(arg) + ? "235 2.7.0 authenticated\r\n" + : "535 5.7.8 bad credentials\r\n"); + } else if (strcmp(line, "AUTH LOGIN") == 0) { + res.saw_auth = 1; + res.saw_auth_login = 1; + srv_write_all(&io, "334 VXNlcm5hbWU6\r\n"); + if (srv_line(&io, line, sizeof line) < 0) + _exit(1); + if (strcmp(line, b64_user) != 0) { + srv_write_all(&io, "535 5.7.8 bad credentials\r\n"); + continue; + } + srv_write_all(&io, "334 UGFzc3dvcmQ6\r\n"); + if (srv_line(&io, line, sizeof line) < 0) + _exit(1); + srv_write_all(&io, strcmp(line, b64_pass) == 0 + ? "235 2.7.0 authenticated\r\n" + : "535 5.7.8 bad credentials\r\n"); + } else if (strncmp(line, "MAIL FROM:", 10) == 0) { + srv_write_all(&io, "250 2.1.0 ok\r\n"); + } else if (strncmp(line, "RCPT TO:", 8) == 0) { + srv_write_all(&io, mode == SRV_RCPT_REJECT + ? "550 5.1.1 no such user\r\n" + : "250 2.1.5 ok\r\n"); + } else if (strcmp(line, "DATA") == 0) { + if (mode == SRV_RCPT_REJECT) { + srv_write_all(&io, "503 5.5.1 need RCPT\r\n"); + } else { + srv_write_all(&io, "354 end with .\r\n"); + in_data = 1; + } + } else if (strcmp(line, "QUIT") == 0) { + srv_write_all(&io, "221 2.0.0 bye\r\n"); + break; + } else { + srv_write_all(&io, "500 5.5.1 unknown command\r\n"); + } + } + + (void)write_full(wfd, &res, sizeof res); + if (data.len) + (void)write_full(wfd, data.p, data.len); + close(wfd); + close(cfd); + buf_free(&data); + free(b64_user); + free(b64_pass); + _exit(0); +} + +struct case_result { + int rc; + char err[512]; + struct srv_result res; + unsigned char data[131072]; + size_t data_len; + int server_ok; +}; + +static void run_case(int mode, struct smtp_message m, struct case_result *out) +{ + signal(SIGPIPE, SIG_IGN); + int pfd[2]; + memset(out, 0, sizeof *out); + if (pipe(pfd) != 0) { + printf("FAIL pipe\n"); + failures++; + return; + } + pid_t pid = fork(); + if (pid == 0) { + close(pfd[0]); + server_main(pfd[1], mode); + } + close(pfd[1]); + int port = 0; + if (read_full(pfd[0], &port, sizeof port) != (ssize_t)sizeof port) + port = 0; + m.port = port; + out->rc = smtp_send(&m, out->err, sizeof out->err); + + struct srv_result res; + memset(&res, 0, sizeof res); + if (read_full(pfd[0], &res, sizeof res) == (ssize_t)sizeof res) { + out->res = res; + size_t cap = res.data_len < sizeof out->data ? res.data_len + : sizeof out->data; + if (cap && read_full(pfd[0], out->data, cap) == (ssize_t)cap) + out->data_len = cap; + } + close(pfd[0]); + int status = 0; + waitpid(pid, &status, 0); + out->server_ok = WIFEXITED(status) && WEXITSTATUS(status) == 0; +} + +static void check_delivered(const char *what, const struct case_result *c) +{ + check(c->server_ok && c->rc == 0, what); + if (c->server_ok && c->rc == 0) + return; + if (!c->server_ok) + printf(" server aborted\n"); + if (c->rc != 0) + printf(" err: %s\n", c->err); +} + +static struct smtp_message base_message(void) +{ + struct smtp_message m; + memset(&m, 0, sizeof m); + m.host = "localhost"; + m.security = "plain"; + m.from = "invoice@example.test"; + m.from_name = "Bokf AB"; + m.to = "kund@example.test"; + m.subject = "Faktura 1001"; + m.body = "Hej!\nBifogad faktura.\n"; + return m; +} + +static const unsigned char pdf[] = + "%PDF-1.4\n1 0 obj\n<< /Type /Catalog >>\nendobj\ntrailer\n" + "<< /Root 1 0 R >>\n%%EOF\n"; + +static void flatten(const unsigned char *data, size_t len, + unsigned char **out, size_t *out_len) +{ + unsigned char *flat = malloc(len + 1); + size_t o = 0; + for (size_t i = 0; i < len; i++) + if (data[i] != '\r' && data[i] != '\n') + flat[o++] = data[i]; + flat[o] = '\0'; + *out = flat; + *out_len = o; +} + +static void check_crlf(const unsigned char *data, size_t len) +{ + int crlf = 1; + int max = 0; + size_t start = 0; + for (size_t i = 0; i < len; i++) { + if (data[i] != '\n') + continue; + size_t l = i - start; + if (l > 0 && data[i - 1] == '\r') + l--; + else + crlf = 0; + if (l > (size_t)max) + max = (int)l; + start = i + 1; + } + check(crlf, "message uses CRLF only"); + check(max > 0 && max < 998, "line lengths under 998"); +} + +static void test_multipart(void) +{ + struct smtp_message m = base_message(); + m.from_name = "Bokf \xc3\x84rende"; + m.subject = "Faktura p\xc3\xa5 svenska"; + m.attach_name = "faktura.pdf"; + m.attach = pdf; + m.attach_len = sizeof pdf - 1; + + struct case_result c; + run_case(SRV_NOAUTH, m, &c); + check_delivered("multipart: delivered", &c); + check(c.res.saw_ehlo == 1, "multipart: one EHLO"); + check(!c.res.saw_auth, "multipart: no AUTH when user empty"); + + const unsigned char *d = c.data; + size_t n = c.data_len; + if (getenv("SMTP_CHECK_DUMP")) + printf("--- message ---\n%.*s\n---\n", (int)n, d); + char *name_word = NULL; + char *subj_word = NULL; + { + char *b = util_b64((const unsigned char *)m.from_name, + strlen(m.from_name)); + size_t l = strlen(b) + 13; + name_word = malloc(l); + snprintf(name_word, l, "=?UTF-8?B?%s?=", b); + free(b); + b = util_b64((const unsigned char *)m.subject, strlen(m.subject)); + l = strlen(b) + 13; + subj_word = malloc(l); + snprintf(subj_word, l, "=?UTF-8?B?%s?=", b); + free(b); + } + char from_hdr[256]; + snprintf(from_hdr, sizeof from_hdr, "From: %s <invoice@example.test>", + name_word); + char subj_hdr[256]; + snprintf(subj_hdr, sizeof subj_hdr, "Subject: %s", subj_word); + + check(contains(d, n, "MIME-Version: 1.0\r\n"), "multipart: MIME-Version"); + check(contains(d, n, from_hdr), "multipart: From with B-encoded name"); + check(contains(d, n, "To: <kund@example.test>\r\n"), "multipart: To"); + check(contains(d, n, subj_hdr), "multipart: B-encoded subject"); + check(contains(d, n, "Date: ") && contains(d, n, "+0000\r\n"), + "multipart: UTC Date"); + check(contains(d, n, "Message-ID: <"), "multipart: Message-ID"); + check(contains(d, n, "Content-Type: multipart/mixed; boundary=\""), + "multipart: multipart content type"); + check(count_occ(d, n, "Content-Type: text/plain; charset=utf-8") == 1, + "multipart: text part"); + check(contains(d, n, "Content-Type: application/pdf; name=\"faktura.pdf\""), + "multipart: attachment type and name"); + check(contains(d, n, + "Content-Disposition: attachment; filename=\"faktura.pdf\""), + "multipart: attachment disposition"); + check(count_occ(d, n, "Content-Transfer-Encoding: base64") == 2, + "multipart: two base64 parts"); + + unsigned char *flat = NULL; + size_t flat_len = 0; + flatten(d, n, &flat, &flat_len); + char *b64 = util_b64(pdf, sizeof pdf - 1); + check(contains(flat, flat_len, b64), "multipart: attachment base64"); + free(b64); + b64 = util_b64((const unsigned char *)m.body, strlen(m.body)); + check(contains(flat, flat_len, b64), "multipart: body base64"); + free(b64); + free(flat); + + check(count_occ(d, n, "--=_bokf_") == 3, "multipart: boundary delimiters"); + check_crlf(d, n); + free(name_word); + free(subj_word); +} + +static void test_text_only(void) +{ + struct smtp_message m = base_message(); + struct case_result c; + run_case(SRV_NOAUTH, m, &c); + check_delivered("text-only: delivered", &c); + const unsigned char *d = c.data; + size_t n = c.data_len; + check(contains(d, n, "From: Bokf AB <invoice@example.test>\r\n"), + "text-only: plain display name"); + check(contains(d, n, "Subject: Faktura 1001\r\n"), + "text-only: plain subject"); + check(contains(d, n, "Content-Type: text/plain; charset=utf-8\r\n"), + "text-only: text content type"); + check(!contains(d, n, "multipart/mixed"), "text-only: not multipart"); + check_crlf(d, n); +} + +static void test_rcpt_reject(void) +{ + struct smtp_message m = base_message(); + m.attach_name = "faktura.pdf"; + m.attach = pdf; + m.attach_len = sizeof pdf - 1; + struct case_result c; + run_case(SRV_RCPT_REJECT, m, &c); + check(c.server_ok, "reject: server completed session"); + check(c.rc == -1, "reject: smtp_send failed"); + check(strstr(c.err, "550") != NULL, "reject: err has 550"); + check(strstr(c.err, "no such user") != NULL, "reject: err has server text"); + check(!contains(c.data, c.data_len, "faktura"), + "reject: no DATA delivered"); +} + +static void test_auth_plain(void) +{ + struct smtp_message m = base_message(); + m.user = "mailer"; + m.password = "s3cret"; + struct case_result c; + run_case(SRV_AUTH_PLAIN, m, &c); + check_delivered("auth plain: delivered", &c); + check(c.res.saw_auth_plain == 1, "auth plain: PLAIN used"); + check(c.res.saw_auth_login == 0, "auth plain: LOGIN not used"); + check(!contains(c.data, c.data_len, "s3cret"), + "auth plain: no secret in message"); +} + +static void test_auth_login(void) +{ + struct smtp_message m = base_message(); + m.user = "mailer"; + m.password = "s3cret"; + struct case_result c; + run_case(SRV_AUTH_LOGIN, m, &c); + check_delivered("auth login: delivered", &c); + check(c.res.saw_auth_login == 1, "auth login: LOGIN used"); + check(c.res.saw_auth_plain == 0, "auth login: PLAIN not used"); +} + +static void test_auth_reject(void) +{ + struct smtp_message m = base_message(); + m.user = "mailer"; + m.password = "wrong"; + struct case_result c; + run_case(SRV_AUTH_PLAIN, m, &c); + check(c.rc == -1, "auth reject: smtp_send failed"); + check(strstr(c.err, "535") != NULL, "auth reject: err has 535"); + check(strstr(c.err, "s3cret") == NULL, "auth reject: no secret in err"); +} + +static void test_validation(void) +{ + char err[256]; + check(smtp_send(NULL, err, sizeof err) == -1, "validation: NULL message"); + + struct smtp_message m = base_message(); + m.port = 25; + m.security = "bogus"; + check(smtp_send(&m, err, sizeof err) == -1, "validation: bad security"); + check(strstr(err, "security") != NULL, "validation: bad security text"); + + m = base_message(); + m.from = ""; + check(smtp_send(&m, err, sizeof err) == -1, "validation: empty from"); + + m = base_message(); + m.host = NULL; + check(smtp_send(&m, err, sizeof err) == -1, "validation: NULL host"); +} + +static int tls_available(void) +{ + return access("tests/tls_test_cert.pem", R_OK) == 0 && + access("tests/tls_test_key.pem", R_OK) == 0; +} + +static void with_test_ca(void (*fn)(struct smtp_message *, struct case_result *)) +{ + char *saved = getenv("SSL_CERT_FILE"); + char *copy = saved ? strdup(saved) : NULL; + setenv("SSL_CERT_FILE", "tests/tls_test_cert.pem", 1); + struct smtp_message m = base_message(); + struct case_result c; + fn(&m, &c); + check_delivered("TLS case delivered", &c); + if (saved) + setenv("SSL_CERT_FILE", copy, 1); + else + unsetenv("SSL_CERT_FILE"); + free(copy); +} + +static void tls_case(struct smtp_message *m, struct case_result *c) +{ + m->security = "tls"; + m->attach_name = "faktura.pdf"; + m->attach = pdf; + m->attach_len = sizeof pdf - 1; + run_case(SRV_TLS, *m, c); +} + +static void starttls_case(struct smtp_message *m, struct case_result *c) +{ + m->security = "starttls"; + m->attach_name = "faktura.pdf"; + m->attach = pdf; + m->attach_len = sizeof pdf - 1; + run_case(SRV_STARTTLS, *m, c); + check(c->res.saw_starttls == 1, "starttls: STARTTLS sent"); + check(c->res.saw_ehlo == 2, "starttls: EHLO before and after"); +} + +int main(void) +{ + signal(SIGPIPE, SIG_IGN); + alarm(120); + + test_multipart(); + test_text_only(); + test_rcpt_reject(); + test_auth_plain(); + test_auth_login(); + test_auth_reject(); + test_validation(); + if (tls_available()) { + with_test_ca(tls_case); + with_test_ca(starttls_case); + } else { + printf("skip TLS cases: tests/tls_test_cert.pem missing\n"); + } + + if (failures) { + printf("%d failures\n", failures); + return 1; + } + puts("all ok"); + return 0; +} |