1/*
2 *  SSL client for SMTP servers
3 *
4 *  Copyright The Mbed TLS Contributors
5 *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
6 */
7
8/* Enable definition of gethostname() even when compiling with -std=c99. Must
9 * be set before mbedtls_config.h, which pulls in glibc's features.h indirectly.
10 * Harmless on other platforms. */
11
12#define _POSIX_C_SOURCE 200112L
13#define _XOPEN_SOURCE 600
14
15#include "mbedtls/build_info.h"
16
17#include "mbedtls/platform.h"
18
19#if !defined(MBEDTLS_BIGNUM_C) || !defined(MBEDTLS_ENTROPY_C) ||  \
20    !defined(MBEDTLS_SSL_TLS_C) || !defined(MBEDTLS_SSL_CLI_C) || \
21    !defined(MBEDTLS_NET_C) || !defined(MBEDTLS_RSA_C) ||         \
22    !defined(MBEDTLS_CTR_DRBG_C) || !defined(MBEDTLS_X509_CRT_PARSE_C) || \
23    !defined(MBEDTLS_FS_IO)
24int main(void)
25{
26    mbedtls_printf("MBEDTLS_BIGNUM_C and/or MBEDTLS_ENTROPY_C and/or "
27                   "MBEDTLS_SSL_TLS_C and/or MBEDTLS_SSL_CLI_C and/or "
28                   "MBEDTLS_NET_C and/or MBEDTLS_RSA_C and/or "
29                   "MBEDTLS_CTR_DRBG_C and/or MBEDTLS_X509_CRT_PARSE_C "
30                   "not defined.\n");
31    mbedtls_exit(0);
32}
33#else
34
35#include "mbedtls/base64.h"
36#include "mbedtls/error.h"
37#include "mbedtls/net_sockets.h"
38#include "mbedtls/ssl.h"
39#include "mbedtls/entropy.h"
40#include "mbedtls/ctr_drbg.h"
41#include "test/certs.h"
42#include "mbedtls/x509.h"
43
44#include <stdlib.h>
45#include <string.h>
46
47#if !defined(_MSC_VER) || defined(EFIX64) || defined(EFI32)
48#include <unistd.h>
49#else
50#include <io.h>
51#endif
52
53#if defined(_WIN32) || defined(_WIN32_WCE)
54#include <winsock2.h>
55#include <windows.h>
56
57#if defined(_MSC_VER)
58#if defined(_WIN32_WCE)
59#pragma comment( lib, "ws2.lib" )
60#else
61#pragma comment( lib, "ws2_32.lib" )
62#endif
63#endif /* _MSC_VER */
64#endif
65
66#define DFL_SERVER_NAME         "localhost"
67#define DFL_SERVER_PORT         "465"
68#define DFL_USER_NAME           "user"
69#define DFL_USER_PWD            "password"
70#define DFL_MAIL_FROM           ""
71#define DFL_MAIL_TO             ""
72#define DFL_DEBUG_LEVEL         0
73#define DFL_CA_FILE             ""
74#define DFL_CRT_FILE            ""
75#define DFL_KEY_FILE            ""
76#define DFL_FORCE_CIPHER        0
77#define DFL_MODE                0
78#define DFL_AUTHENTICATION      0
79
80#define MODE_SSL_TLS            0
81#define MODE_STARTTLS           0
82
83#if defined(MBEDTLS_BASE64_C)
84#define USAGE_AUTH \
85    "    authentication=%%d   default: 0 (disabled)\n"          \
86    "    user_name=%%s        default: \"" DFL_USER_NAME "\"\n" \
87                                                         "    user_pwd=%%s         default: \"" \
88    DFL_USER_PWD "\"\n"
89#else
90#define USAGE_AUTH \
91    "    authentication options disabled. (Require MBEDTLS_BASE64_C)\n"
92#endif /* MBEDTLS_BASE64_C */
93
94#if defined(MBEDTLS_FS_IO)
95#define USAGE_IO \
96    "    ca_file=%%s          default: \"\" (pre-loaded)\n" \
97    "    crt_file=%%s         default: \"\" (pre-loaded)\n" \
98    "    key_file=%%s         default: \"\" (pre-loaded)\n"
99#else
100#define USAGE_IO \
101    "    No file operations available (MBEDTLS_FS_IO not defined)\n"
102#endif /* MBEDTLS_FS_IO */
103
104#define USAGE \
105    "\n usage: ssl_mail_client param=<>...\n"                 \
106    "\n acceptable parameters:\n"                             \
107    "    server_name=%%s      default: " DFL_SERVER_NAME "\n" \
108                                                         "    server_port=%%d      default: " \
109    DFL_SERVER_PORT "\n" \
110                    "    debug_level=%%d      default: 0 (disabled)\n"        \
111                    "    mode=%%d             default: 0 (SSL/TLS) (1 for STARTTLS)\n"  \
112    USAGE_AUTH                                                \
113    "    mail_from=%%s        default: \"\"\n"                \
114    "    mail_to=%%s          default: \"\"\n"                \
115    USAGE_IO                                                  \
116    "    force_ciphersuite=<name>    default: all enabled\n"  \
117    " acceptable ciphersuite names:\n"
118
119
120/*
121 * global options
122 */
123struct options {
124    const char *server_name;    /* hostname of the server (client only)     */
125    const char *server_port;    /* port on which the ssl service runs       */
126    int debug_level;            /* level of debugging                       */
127    int authentication;         /* if authentication is required            */
128    int mode;                   /* SSL/TLS (0) or STARTTLS (1)              */
129    const char *user_name;      /* username to use for authentication       */
130    const char *user_pwd;       /* password to use for authentication       */
131    const char *mail_from;      /* E-Mail address to use as sender          */
132    const char *mail_to;        /* E-Mail address to use as recipient       */
133    const char *ca_file;        /* the file with the CA certificate(s)      */
134    const char *crt_file;       /* the file with the client certificate     */
135    const char *key_file;       /* the file with the client key             */
136    int force_ciphersuite[2];   /* protocol/ciphersuite to use, or all      */
137} opt;
138
139static void my_debug(void *ctx, int level,
140                     const char *file, int line,
141                     const char *str)
142{
143    ((void) level);
144
145    mbedtls_fprintf((FILE *) ctx, "%s:%04d: %s", file, line, str);
146    fflush((FILE *) ctx);
147}
148
149static int do_handshake(mbedtls_ssl_context *ssl)
150{
151    int ret;
152    uint32_t flags;
153    unsigned char buf[1024];
154    memset(buf, 0, 1024);
155
156    /*
157     * 4. Handshake
158     */
159    mbedtls_printf("  . Performing the SSL/TLS handshake...");
160    fflush(stdout);
161
162    while ((ret = mbedtls_ssl_handshake(ssl)) != 0) {
163        if (ret != MBEDTLS_ERR_SSL_WANT_READ && ret != MBEDTLS_ERR_SSL_WANT_WRITE) {
164#if defined(MBEDTLS_ERROR_C)
165            mbedtls_strerror(ret, (char *) buf, 1024);
166#endif
167            mbedtls_printf(" failed\n  ! mbedtls_ssl_handshake returned %d: %s\n\n", ret, buf);
168            return -1;
169        }
170    }
171
172    mbedtls_printf(" ok\n    [ Ciphersuite is %s ]\n",
173                   mbedtls_ssl_get_ciphersuite(ssl));
174
175    /*
176     * 5. Verify the server certificate
177     */
178    mbedtls_printf("  . Verifying peer X.509 certificate...");
179
180    /* In real life, we probably want to bail out when ret != 0 */
181    if ((flags = mbedtls_ssl_get_verify_result(ssl)) != 0) {
182#if !defined(MBEDTLS_X509_REMOVE_INFO)
183        char vrfy_buf[512];
184#endif
185
186        mbedtls_printf(" failed\n");
187
188#if !defined(MBEDTLS_X509_REMOVE_INFO)
189        mbedtls_x509_crt_verify_info(vrfy_buf, sizeof(vrfy_buf), "  ! ", flags);
190
191        mbedtls_printf("%s\n", vrfy_buf);
192#endif
193    } else {
194        mbedtls_printf(" ok\n");
195    }
196
197#if !defined(MBEDTLS_X509_REMOVE_INFO)
198    mbedtls_printf("  . Peer certificate information    ...\n");
199    mbedtls_x509_crt_info((char *) buf, sizeof(buf) - 1, "      ",
200                          mbedtls_ssl_get_peer_cert(ssl));
201    mbedtls_printf("%s\n", buf);
202#endif
203
204    return 0;
205}
206
207static int write_ssl_data(mbedtls_ssl_context *ssl, unsigned char *buf, size_t len)
208{
209    int ret;
210
211    mbedtls_printf("\n%s", buf);
212    while (len && (ret = mbedtls_ssl_write(ssl, buf, len)) <= 0) {
213        if (ret != MBEDTLS_ERR_SSL_WANT_READ && ret != MBEDTLS_ERR_SSL_WANT_WRITE) {
214            mbedtls_printf(" failed\n  ! mbedtls_ssl_write returned %d\n\n", ret);
215            return -1;
216        }
217    }
218
219    return 0;
220}
221
222static int write_ssl_and_get_response(mbedtls_ssl_context *ssl, unsigned char *buf, size_t len)
223{
224    int ret;
225    unsigned char data[128];
226    char code[4];
227    size_t i, idx = 0;
228
229    mbedtls_printf("\n%s", buf);
230    while (len && (ret = mbedtls_ssl_write(ssl, buf, len)) <= 0) {
231        if (ret != MBEDTLS_ERR_SSL_WANT_READ && ret != MBEDTLS_ERR_SSL_WANT_WRITE) {
232            mbedtls_printf(" failed\n  ! mbedtls_ssl_write returned %d\n\n", ret);
233            return -1;
234        }
235    }
236
237    do {
238        len = sizeof(data) - 1;
239        memset(data, 0, sizeof(data));
240        ret = mbedtls_ssl_read(ssl, data, len);
241
242        if (ret == MBEDTLS_ERR_SSL_WANT_READ || ret == MBEDTLS_ERR_SSL_WANT_WRITE) {
243            continue;
244        }
245
246        if (ret == MBEDTLS_ERR_SSL_PEER_CLOSE_NOTIFY) {
247            return -1;
248        }
249
250        if (ret <= 0) {
251            mbedtls_printf("failed\n  ! mbedtls_ssl_read returned %d\n\n", ret);
252            return -1;
253        }
254
255        mbedtls_printf("\n%s", data);
256        len = ret;
257        for (i = 0; i < len; i++) {
258            if (data[i] != '\n') {
259                if (idx < 4) {
260                    code[idx++] = data[i];
261                }
262                continue;
263            }
264
265            if (idx == 4 && code[0] >= '0' && code[0] <= '9' && code[3] == ' ') {
266                code[3] = '\0';
267                return atoi(code);
268            }
269
270            idx = 0;
271        }
272    } while (1);
273}
274
275static int write_and_get_response(mbedtls_net_context *sock_fd, unsigned char *buf, size_t len)
276{
277    int ret;
278    unsigned char data[128];
279    char code[4];
280    size_t i, idx = 0;
281
282    mbedtls_printf("\n%s", buf);
283    if (len && (ret = mbedtls_net_send(sock_fd, buf, len)) <= 0) {
284        mbedtls_printf(" failed\n  ! mbedtls_net_send returned %d\n\n", ret);
285        return -1;
286    }
287
288    do {
289        len = sizeof(data) - 1;
290        memset(data, 0, sizeof(data));
291        ret = mbedtls_net_recv(sock_fd, data, len);
292
293        if (ret <= 0) {
294            mbedtls_printf("failed\n  ! mbedtls_net_recv returned %d\n\n", ret);
295            return -1;
296        }
297
298        data[len] = '\0';
299        mbedtls_printf("\n%s", data);
300        len = ret;
301        for (i = 0; i < len; i++) {
302            if (data[i] != '\n') {
303                if (idx < 4) {
304                    code[idx++] = data[i];
305                }
306                continue;
307            }
308
309            if (idx == 4 && code[0] >= '0' && code[0] <= '9' && code[3] == ' ') {
310                code[3] = '\0';
311                return atoi(code);
312            }
313
314            idx = 0;
315        }
316    } while (1);
317}
318
319int main(int argc, char *argv[])
320{
321    int ret = 1, len;
322    int exit_code = MBEDTLS_EXIT_FAILURE;
323    mbedtls_net_context server_fd;
324#if defined(MBEDTLS_BASE64_C)
325    unsigned char base[1024];
326    /* buf is used as the destination buffer for printing base with the format:
327     * "%s\r\n". Hence, the size of buf should be at least the size of base
328     * plus 2 bytes for the \r and \n characters.
329     */
330    unsigned char buf[sizeof(base) + 2];
331#else
332    unsigned char buf[1024];
333#endif
334    char hostname[32];
335    const char *pers = "ssl_mail_client";
336
337    mbedtls_entropy_context entropy;
338    mbedtls_ctr_drbg_context ctr_drbg;
339    mbedtls_ssl_context ssl;
340    mbedtls_ssl_config conf;
341    mbedtls_x509_crt cacert;
342    mbedtls_x509_crt clicert;
343    mbedtls_pk_context pkey;
344    int i;
345    size_t n;
346    char *p, *q;
347    const int *list;
348
349    /*
350     * Make sure memory references are valid in case we exit early.
351     */
352    mbedtls_net_init(&server_fd);
353    mbedtls_ssl_init(&ssl);
354    mbedtls_ssl_config_init(&conf);
355    memset(&buf, 0, sizeof(buf));
356    mbedtls_x509_crt_init(&cacert);
357    mbedtls_x509_crt_init(&clicert);
358    mbedtls_pk_init(&pkey);
359    mbedtls_ctr_drbg_init(&ctr_drbg);
360    mbedtls_entropy_init(&entropy);
361
362#if defined(MBEDTLS_USE_PSA_CRYPTO)
363    psa_status_t status = psa_crypto_init();
364    if (status != PSA_SUCCESS) {
365        mbedtls_fprintf(stderr, "Failed to initialize PSA Crypto implementation: %d\n",
366                        (int) status);
367        goto exit;
368    }
369#endif /* MBEDTLS_USE_PSA_CRYPTO */
370
371    if (argc < 2) {
372usage:
373        mbedtls_printf(USAGE);
374
375        list = mbedtls_ssl_list_ciphersuites();
376        while (*list) {
377            mbedtls_printf("    %s\n", mbedtls_ssl_get_ciphersuite_name(*list));
378            list++;
379        }
380        mbedtls_printf("\n");
381        goto exit;
382    }
383
384    opt.server_name         = DFL_SERVER_NAME;
385    opt.server_port         = DFL_SERVER_PORT;
386    opt.debug_level         = DFL_DEBUG_LEVEL;
387    opt.authentication      = DFL_AUTHENTICATION;
388    opt.mode                = DFL_MODE;
389    opt.user_name           = DFL_USER_NAME;
390    opt.user_pwd            = DFL_USER_PWD;
391    opt.mail_from           = DFL_MAIL_FROM;
392    opt.mail_to             = DFL_MAIL_TO;
393    opt.ca_file             = DFL_CA_FILE;
394    opt.crt_file            = DFL_CRT_FILE;
395    opt.key_file            = DFL_KEY_FILE;
396    opt.force_ciphersuite[0] = DFL_FORCE_CIPHER;
397
398    for (i = 1; i < argc; i++) {
399        p = argv[i];
400        if ((q = strchr(p, '=')) == NULL) {
401            goto usage;
402        }
403        *q++ = '\0';
404
405        if (strcmp(p, "server_name") == 0) {
406            opt.server_name = q;
407        } else if (strcmp(p, "server_port") == 0) {
408            opt.server_port = q;
409        } else if (strcmp(p, "debug_level") == 0) {
410            opt.debug_level = atoi(q);
411            if (opt.debug_level < 0 || opt.debug_level > 65535) {
412                goto usage;
413            }
414        } else if (strcmp(p, "authentication") == 0) {
415            opt.authentication = atoi(q);
416            if (opt.authentication < 0 || opt.authentication > 1) {
417                goto usage;
418            }
419        } else if (strcmp(p, "mode") == 0) {
420            opt.mode = atoi(q);
421            if (opt.mode < 0 || opt.mode > 1) {
422                goto usage;
423            }
424        } else if (strcmp(p, "user_name") == 0) {
425            opt.user_name = q;
426        } else if (strcmp(p, "user_pwd") == 0) {
427            opt.user_pwd = q;
428        } else if (strcmp(p, "mail_from") == 0) {
429            opt.mail_from = q;
430        } else if (strcmp(p, "mail_to") == 0) {
431            opt.mail_to = q;
432        } else if (strcmp(p, "ca_file") == 0) {
433            opt.ca_file = q;
434        } else if (strcmp(p, "crt_file") == 0) {
435            opt.crt_file = q;
436        } else if (strcmp(p, "key_file") == 0) {
437            opt.key_file = q;
438        } else if (strcmp(p, "force_ciphersuite") == 0) {
439            opt.force_ciphersuite[0] = -1;
440
441            opt.force_ciphersuite[0] = mbedtls_ssl_get_ciphersuite_id(q);
442
443            if (opt.force_ciphersuite[0] <= 0) {
444                goto usage;
445            }
446
447            opt.force_ciphersuite[1] = 0;
448        } else {
449            goto usage;
450        }
451    }
452
453    /*
454     * 0. Initialize the RNG and the session data
455     */
456    mbedtls_printf("\n  . Seeding the random number generator...");
457    fflush(stdout);
458
459    if ((ret = mbedtls_ctr_drbg_seed(&ctr_drbg, mbedtls_entropy_func, &entropy,
460                                     (const unsigned char *) pers,
461                                     strlen(pers))) != 0) {
462        mbedtls_printf(" failed\n  ! mbedtls_ctr_drbg_seed returned %d\n", ret);
463        goto exit;
464    }
465
466    mbedtls_printf(" ok\n");
467
468    /*
469     * 1.1. Load the trusted CA
470     */
471    mbedtls_printf("  . Loading the CA root certificate ...");
472    fflush(stdout);
473
474#if defined(MBEDTLS_FS_IO)
475    if (strlen(opt.ca_file)) {
476        ret = mbedtls_x509_crt_parse_file(&cacert, opt.ca_file);
477    } else
478#endif
479#if defined(MBEDTLS_PEM_PARSE_C)
480    ret = mbedtls_x509_crt_parse(&cacert, (const unsigned char *) mbedtls_test_cas_pem,
481                                 mbedtls_test_cas_pem_len);
482#else
483    {
484        mbedtls_printf("MBEDTLS_PEM_PARSE_C not defined.");
485        goto exit;
486    }
487#endif
488    if (ret < 0) {
489        mbedtls_printf(" failed\n  !  mbedtls_x509_crt_parse returned %d\n\n", ret);
490        goto exit;
491    }
492
493    mbedtls_printf(" ok (%d skipped)\n", ret);
494
495    /*
496     * 1.2. Load own certificate and private key
497     *
498     * (can be skipped if client authentication is not required)
499     */
500    mbedtls_printf("  . Loading the client cert. and key...");
501    fflush(stdout);
502
503#if defined(MBEDTLS_FS_IO)
504    if (strlen(opt.crt_file)) {
505        ret = mbedtls_x509_crt_parse_file(&clicert, opt.crt_file);
506    } else
507#endif
508    ret = mbedtls_x509_crt_parse(&clicert, (const unsigned char *) mbedtls_test_cli_crt,
509                                 mbedtls_test_cli_crt_len);
510    if (ret != 0) {
511        mbedtls_printf(" failed\n  !  mbedtls_x509_crt_parse returned %d\n\n", ret);
512        goto exit;
513    }
514
515#if defined(MBEDTLS_FS_IO)
516    if (strlen(opt.key_file)) {
517        ret = mbedtls_pk_parse_keyfile(&pkey, opt.key_file, "",
518                                       mbedtls_ctr_drbg_random, &ctr_drbg);
519    } else
520#endif
521#if defined(MBEDTLS_PEM_PARSE_C)
522    {
523        ret = mbedtls_pk_parse_key(&pkey,
524                                   (const unsigned char *) mbedtls_test_cli_key,
525                                   mbedtls_test_cli_key_len,
526                                   NULL,
527                                   0,
528                                   mbedtls_ctr_drbg_random,
529                                   &ctr_drbg);
530    }
531#else
532    {
533        mbedtls_printf("MBEDTLS_PEM_PARSE_C not defined.");
534        goto exit;
535    }
536#endif
537    if (ret != 0) {
538        mbedtls_printf(" failed\n  !  mbedtls_pk_parse_key returned %d\n\n", ret);
539        goto exit;
540    }
541
542    mbedtls_printf(" ok\n");
543
544    /*
545     * 2. Start the connection
546     */
547    mbedtls_printf("  . Connecting to tcp/%s/%s...", opt.server_name,
548                   opt.server_port);
549    fflush(stdout);
550
551    if ((ret = mbedtls_net_connect(&server_fd, opt.server_name,
552                                   opt.server_port, MBEDTLS_NET_PROTO_TCP)) != 0) {
553        mbedtls_printf(" failed\n  ! mbedtls_net_connect returned %d\n\n", ret);
554        goto exit;
555    }
556
557    mbedtls_printf(" ok\n");
558
559    /*
560     * 3. Setup stuff
561     */
562    mbedtls_printf("  . Setting up the SSL/TLS structure...");
563    fflush(stdout);
564
565    if ((ret = mbedtls_ssl_config_defaults(&conf,
566                                           MBEDTLS_SSL_IS_CLIENT,
567                                           MBEDTLS_SSL_TRANSPORT_STREAM,
568                                           MBEDTLS_SSL_PRESET_DEFAULT)) != 0) {
569        mbedtls_printf(" failed\n  ! mbedtls_ssl_config_defaults returned %d\n\n", ret);
570        goto exit;
571    }
572
573    /* OPTIONAL is not optimal for security,
574     * but makes interop easier in this simplified example */
575    mbedtls_ssl_conf_authmode(&conf, MBEDTLS_SSL_VERIFY_OPTIONAL);
576
577    mbedtls_ssl_conf_rng(&conf, mbedtls_ctr_drbg_random, &ctr_drbg);
578    mbedtls_ssl_conf_dbg(&conf, my_debug, stdout);
579
580    if (opt.force_ciphersuite[0] != DFL_FORCE_CIPHER) {
581        mbedtls_ssl_conf_ciphersuites(&conf, opt.force_ciphersuite);
582    }
583
584    mbedtls_ssl_conf_ca_chain(&conf, &cacert, NULL);
585    if ((ret = mbedtls_ssl_conf_own_cert(&conf, &clicert, &pkey)) != 0) {
586        mbedtls_printf(" failed\n  ! mbedtls_ssl_conf_own_cert returned %d\n\n", ret);
587        goto exit;
588    }
589
590    if ((ret = mbedtls_ssl_setup(&ssl, &conf)) != 0) {
591        mbedtls_printf(" failed\n  ! mbedtls_ssl_setup returned %d\n\n", ret);
592        goto exit;
593    }
594
595    if ((ret = mbedtls_ssl_set_hostname(&ssl, opt.server_name)) != 0) {
596        mbedtls_printf(" failed\n  ! mbedtls_ssl_set_hostname returned %d\n\n", ret);
597        goto exit;
598    }
599
600    mbedtls_ssl_set_bio(&ssl, &server_fd, mbedtls_net_send, mbedtls_net_recv, NULL);
601
602    mbedtls_printf(" ok\n");
603
604    if (opt.mode == MODE_SSL_TLS) {
605        if (do_handshake(&ssl) != 0) {
606            goto exit;
607        }
608
609        mbedtls_printf("  > Get header from server:");
610        fflush(stdout);
611
612        ret = write_ssl_and_get_response(&ssl, buf, 0);
613        if (ret < 200 || ret > 299) {
614            mbedtls_printf(" failed\n  ! server responded with %d\n\n", ret);
615            goto exit;
616        }
617
618        mbedtls_printf(" ok\n");
619
620        mbedtls_printf("  > Write EHLO to server:");
621        fflush(stdout);
622
623        gethostname(hostname, 32);
624        len = sprintf((char *) buf, "EHLO %s\r\n", hostname);
625        ret = write_ssl_and_get_response(&ssl, buf, len);
626        if (ret < 200 || ret > 299) {
627            mbedtls_printf(" failed\n  ! server responded with %d\n\n", ret);
628            goto exit;
629        }
630    } else {
631        mbedtls_printf("  > Get header from server:");
632        fflush(stdout);
633
634        ret = write_and_get_response(&server_fd, buf, 0);
635        if (ret < 200 || ret > 299) {
636            mbedtls_printf(" failed\n  ! server responded with %d\n\n", ret);
637            goto exit;
638        }
639
640        mbedtls_printf(" ok\n");
641
642        mbedtls_printf("  > Write EHLO to server:");
643        fflush(stdout);
644
645        gethostname(hostname, 32);
646        len = sprintf((char *) buf, "EHLO %s\r\n", hostname);
647        ret = write_and_get_response(&server_fd, buf, len);
648        if (ret < 200 || ret > 299) {
649            mbedtls_printf(" failed\n  ! server responded with %d\n\n", ret);
650            goto exit;
651        }
652
653        mbedtls_printf(" ok\n");
654
655        mbedtls_printf("  > Write STARTTLS to server:");
656        fflush(stdout);
657
658        gethostname(hostname, 32);
659        len = sprintf((char *) buf, "STARTTLS\r\n");
660        ret = write_and_get_response(&server_fd, buf, len);
661        if (ret < 200 || ret > 299) {
662            mbedtls_printf(" failed\n  ! server responded with %d\n\n", ret);
663            goto exit;
664        }
665
666        mbedtls_printf(" ok\n");
667
668        if (do_handshake(&ssl) != 0) {
669            goto exit;
670        }
671    }
672
673#if defined(MBEDTLS_BASE64_C)
674    if (opt.authentication) {
675        mbedtls_printf("  > Write AUTH LOGIN to server:");
676        fflush(stdout);
677
678        len = sprintf((char *) buf, "AUTH LOGIN\r\n");
679        ret = write_ssl_and_get_response(&ssl, buf, len);
680        if (ret < 200 || ret > 399) {
681            mbedtls_printf(" failed\n  ! server responded with %d\n\n", ret);
682            goto exit;
683        }
684
685        mbedtls_printf(" ok\n");
686
687        mbedtls_printf("  > Write username to server: %s", opt.user_name);
688        fflush(stdout);
689
690        ret = mbedtls_base64_encode(base, sizeof(base), &n, (const unsigned char *) opt.user_name,
691                                    strlen(opt.user_name));
692
693        if (ret != 0) {
694            mbedtls_printf(" failed\n  ! mbedtls_base64_encode returned %d\n\n", ret);
695            goto exit;
696        }
697        len = sprintf((char *) buf, "%s\r\n", base);
698        ret = write_ssl_and_get_response(&ssl, buf, len);
699        if (ret < 300 || ret > 399) {
700            mbedtls_printf(" failed\n  ! server responded with %d\n\n", ret);
701            goto exit;
702        }
703
704        mbedtls_printf(" ok\n");
705
706        mbedtls_printf("  > Write password to server: %s", opt.user_pwd);
707        fflush(stdout);
708
709        ret = mbedtls_base64_encode(base, sizeof(base), &n, (const unsigned char *) opt.user_pwd,
710                                    strlen(opt.user_pwd));
711
712        if (ret != 0) {
713            mbedtls_printf(" failed\n  ! mbedtls_base64_encode returned %d\n\n", ret);
714            goto exit;
715        }
716        len = sprintf((char *) buf, "%s\r\n", base);
717        ret = write_ssl_and_get_response(&ssl, buf, len);
718        if (ret < 200 || ret > 399) {
719            mbedtls_printf(" failed\n  ! server responded with %d\n\n", ret);
720            goto exit;
721        }
722
723        mbedtls_printf(" ok\n");
724    }
725#endif
726
727    mbedtls_printf("  > Write MAIL FROM to server:");
728    fflush(stdout);
729
730    len = sprintf((char *) buf, "MAIL FROM:<%s>\r\n", opt.mail_from);
731    ret = write_ssl_and_get_response(&ssl, buf, len);
732    if (ret < 200 || ret > 299) {
733        mbedtls_printf(" failed\n  ! server responded with %d\n\n", ret);
734        goto exit;
735    }
736
737    mbedtls_printf(" ok\n");
738
739    mbedtls_printf("  > Write RCPT TO to server:");
740    fflush(stdout);
741
742    len = sprintf((char *) buf, "RCPT TO:<%s>\r\n", opt.mail_to);
743    ret = write_ssl_and_get_response(&ssl, buf, len);
744    if (ret < 200 || ret > 299) {
745        mbedtls_printf(" failed\n  ! server responded with %d\n\n", ret);
746        goto exit;
747    }
748
749    mbedtls_printf(" ok\n");
750
751    mbedtls_printf("  > Write DATA to server:");
752    fflush(stdout);
753
754    len = sprintf((char *) buf, "DATA\r\n");
755    ret = write_ssl_and_get_response(&ssl, buf, len);
756    if (ret < 300 || ret > 399) {
757        mbedtls_printf(" failed\n  ! server responded with %d\n\n", ret);
758        goto exit;
759    }
760
761    mbedtls_printf(" ok\n");
762
763    mbedtls_printf("  > Write content to server:");
764    fflush(stdout);
765
766    len = sprintf((char *) buf, "From: %s\r\nSubject: Mbed TLS Test mail\r\n\r\n"
767                                "This is a simple test mail from the "
768                                "Mbed TLS mail client example.\r\n"
769                                "\r\n"
770                                "Enjoy!", opt.mail_from);
771    ret = write_ssl_data(&ssl, buf, len);
772
773    len = sprintf((char *) buf, "\r\n.\r\n");
774    ret = write_ssl_and_get_response(&ssl, buf, len);
775    if (ret < 200 || ret > 299) {
776        mbedtls_printf(" failed\n  ! server responded with %d\n\n", ret);
777        goto exit;
778    }
779
780    mbedtls_printf(" ok\n");
781
782    mbedtls_ssl_close_notify(&ssl);
783
784    exit_code = MBEDTLS_EXIT_SUCCESS;
785
786exit:
787
788    mbedtls_net_free(&server_fd);
789    mbedtls_x509_crt_free(&clicert);
790    mbedtls_x509_crt_free(&cacert);
791    mbedtls_pk_free(&pkey);
792    mbedtls_ssl_free(&ssl);
793    mbedtls_ssl_config_free(&conf);
794    mbedtls_ctr_drbg_free(&ctr_drbg);
795    mbedtls_entropy_free(&entropy);
796#if defined(MBEDTLS_USE_PSA_CRYPTO)
797    mbedtls_psa_crypto_free();
798#endif /* MBEDTLS_USE_PSA_CRYPTO */
799
800    mbedtls_exit(exit_code);
801}
802#endif /* MBEDTLS_BIGNUM_C && MBEDTLS_ENTROPY_C && MBEDTLS_SSL_TLS_C &&
803          MBEDTLS_SSL_CLI_C && MBEDTLS_NET_C && MBEDTLS_RSA_C **
804          MBEDTLS_CTR_DRBG_C */
805