[people/ms/dma.git] / crypto.c

/*
 * Copyright (c) 2008 The DragonFly Project.  All rights reserved.
 *
 * This code is derived from software contributed to The DragonFly Project
 * by Matthias Schmidt <matthias@dragonflybsd.org>, University of Marburg,
 * Germany.
 *
 * 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.
 * 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. Neither the name of The DragonFly Project nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific, prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``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
 * COPYRIGHT HOLDERS OR CONTRIBUTORS 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.
 *
 * $DragonFly: src/libexec/dma/crypto.c,v 1.3 2008/09/02 15:11:49 matthias Exp $
 */

#ifdef HAVE_CRYPTO

#include <openssl/x509.h>
#include <openssl/md5.h>
#include <openssl/ssl.h>
#include <openssl/err.h>
#include <openssl/pem.h>
#include <openssl/rand.h>

#include <syslog.h>

#include "dma.h"

extern struct config *config;

static int
init_cert_file(struct qitem *it, SSL_CTX *ctx, const char *path)
{
	int error;

	/* Load certificate into ctx */
	error = SSL_CTX_use_certificate_chain_file(ctx, path);
	if (error < 1) {
		syslog(LOG_ERR, "%s: SSL: Cannot load certificate: %s",
			it->queueid, path);
		return (-1);
	}

	/* Add private key to ctx */
	error = SSL_CTX_use_PrivateKey_file(ctx, path, SSL_FILETYPE_PEM);
	if (error < 1) {
		syslog(LOG_ERR, "%s: SSL: Cannot load private key: %s",
			it->queueid, path);
		return (-1);
	}

	/*
	 * Check the consistency of a private key with the corresponding
         * certificate
	 */
	error = SSL_CTX_check_private_key(ctx);
	if (error < 1) {
		syslog(LOG_ERR, "%s: SSL: Cannot check private key: %s",
			it->queueid, path);
		return (-1);
	}

	return (0);
}

int
smtp_init_crypto(struct qitem *it, int fd, int feature)
{
	SSL_CTX *ctx = NULL;
	SSL_METHOD *meth = NULL;
	X509 *cert;
	char buf[2048];
	int error;

	/* Init SSL library */
	SSL_library_init();

	meth = TLSv1_client_method();

	ctx = SSL_CTX_new(meth);
	if (ctx == NULL) {
		syslog(LOG_ERR, "%s: remote delivery deferred:"
		       " SSL init failed: %m", it->queueid);
		return (2);
	}

	/* User supplied a certificate */
	if (config->certfile != NULL)
		init_cert_file(it, ctx, config->certfile);

	/*
	 * If the user wants STARTTLS, we have to send EHLO here
	 */
	if (((feature & SECURETRANS) != 0) &&
	     (feature & STARTTLS) != 0) {
		/* TLS init phase, disable SSL_write */
		config->features |= NOSSL;

		send_remote_command(fd, "EHLO %s", hostname());
		if (read_remote(fd, 0, NULL) == 2) {
			send_remote_command(fd, "STARTTLS");
			if (read_remote(fd, 0, NULL) != 2) {
				syslog(LOG_ERR, "%s: remote delivery failed:"
				  " STARTTLS not available: %m", it->queueid);
				config->features &= ~NOSSL;
				return (-1);
			}
		}
		/* End of TLS init phase, enable SSL_write/read */
		config->features &= ~NOSSL;
	}

	config->ssl = SSL_new(ctx);
	if (config->ssl == NULL) {
		syslog(LOG_ERR, "%s: remote delivery deferred:"
		       " SSL struct creation failed:", it->queueid);
		return (2);
	}

	/* Set ssl to work in client mode */
	SSL_set_connect_state(config->ssl);

	/* Set fd for SSL in/output */
	error = SSL_set_fd(config->ssl, fd);
	if (error == 0) {
		error = SSL_get_error(config->ssl, error);
		syslog(LOG_ERR, "%s: remote delivery deferred:"
		       " SSL set fd failed (%d): %m", it->queueid, error);
		return (2);
	}

	/* Open SSL connection */
	error = SSL_connect(config->ssl);
	if (error < 0) {
		syslog(LOG_ERR, "%s: remote delivery failed:"
		       " SSL handshake fataly failed: %m", it->queueid);
		return (-1);
	}

	/* Get peer certificate */
	cert = SSL_get_peer_certificate(config->ssl);
	if (cert == NULL) {
		syslog(LOG_ERR, "%s: remote delivery deferred:"
		       " Peer did not provied certificate: %m", it->queueid);
	}
	X509_free(cert);

	return (0);
}

/*
 * hmac_md5() taken out of RFC 2104.  This RFC was written by H. Krawczyk,
 * M. Bellare and R. Canetti.
 */ 
void
hmac_md5(text, text_len, key, key_len, digest)
unsigned char*  text;                /* pointer to data stream */
int             text_len;            /* length of data stream */
unsigned char*  key;                 /* pointer to authentication key */
int             key_len;             /* length of authentication key */
caddr_t         digest;              /* caller digest to be filled in */

{
        MD5_CTX context;
        unsigned char k_ipad[65];    /* inner padding -
                                      * key XORd with ipad
                                      */
        unsigned char k_opad[65];    /* outer padding -
                                      * key XORd with opad
                                      */
        unsigned char tk[16];
        int i;
        /* if key is longer than 64 bytes reset it to key=MD5(key) */
        if (key_len > 64) {

                MD5_CTX      tctx;

                MD5_Init(&tctx);
                MD5_Update(&tctx, key, key_len);
                MD5_Final(tk, &tctx);

                key = tk;
                key_len = 16;
        }

        /*
         * the HMAC_MD5 transform looks like:
         *
         * MD5(K XOR opad, MD5(K XOR ipad, text))
         *
         * where K is an n byte key
         * ipad is the byte 0x36 repeated 64 times
	 *
         * opad is the byte 0x5c repeated 64 times
         * and text is the data being protected
         */

        /* start out by storing key in pads */
        bzero( k_ipad, sizeof k_ipad);
        bzero( k_opad, sizeof k_opad);
        bcopy( key, k_ipad, key_len);
        bcopy( key, k_opad, key_len);

        /* XOR key with ipad and opad values */
        for (i=0; i<64; i++) {
                k_ipad[i] ^= 0x36;
                k_opad[i] ^= 0x5c;
        }
        /*
         * perform inner MD5
         */
        MD5_Init(&context);                   /* init context for 1st
                                              * pass */
        MD5_Update(&context, k_ipad, 64);     /* start with inner pad */
        MD5_Update(&context, text, text_len); /* then text of datagram */
        MD5_Final(digest, &context);          /* finish up 1st pass */
        /*
         * perform outer MD5
         */
        MD5_Init(&context);                   /* init context for 2nd
                                              * pass */
        MD5_Update(&context, k_opad, 64);     /* start with outer pad */
        MD5_Update(&context, digest, 16);     /* then results of 1st
                                              * hash */
        MD5_Final(digest, &context);          /* finish up 2nd pass */
}

/*
 * CRAM-MD5 authentication
 */
int
smtp_auth_md5(struct qitem *it, int fd, char *login, char *password)
{
	unsigned char buffer[BUF_SIZE], digest[BUF_SIZE], ascii_digest[33];
	char *temp;
	int len, i;
	static char hextab[] = "0123456789abcdef";

	temp = calloc(BUF_SIZE, 1);
	memset(buffer, 0, sizeof(buffer));
	memset(digest, 0, sizeof(digest));
	memset(ascii_digest, 0, sizeof(ascii_digest));

	/* Send AUTH command according to RFC 2554 */
	send_remote_command(fd, "AUTH CRAM-MD5");
	if (read_remote(fd, sizeof(buffer), buffer) != 3) {
		syslog(LOG_ERR, "%s: smarthost authentification:"
		       " AUTH cram-md5 not available: %m", it->queueid);
		/* if cram-md5 is not available */
		return (-1);
	}

	/* skip 3 char status + 1 char space */
	base64_decode(buffer + 4, temp);
	hmac_md5(temp, strlen(temp), password, strlen(password), digest);

	ascii_digest[32] = 0;
	for (i = 0; i < 16; i++) {
		ascii_digest[2*i] = hextab[digest[i] >> 4];
		ascii_digest[2*i+1] = hextab[digest[i] & 15];
	}

	/* prepare answer */
	snprintf(buffer, BUF_SIZE, "%s %s", login, ascii_digest);

	/* temp will be allocated inside base64_encode again */
	free(temp);
	/* encode answer */
	len = base64_encode(buffer, strlen(buffer), &temp);
	if (len <= 0)
		return (-1);

	/* send answer */
	send_remote_command(fd, "%s", temp);
	if (read_remote(fd, 0, NULL) != 2) {
		syslog(LOG_ERR, "%s: remote delivery deferred:"
				" AUTH cram-md5 failed: %m", it->queueid);
		return (-2);
	}

	return (0);
}

#endif /* HAVE_CRYPTO */
Commit	Line	Data
86e4d161 MS	1	/*
	2	* Copyright (c) 2008 The DragonFly Project. All rights reserved.
	3	*
	4	* This code is derived from software contributed to The DragonFly Project
	5	* by Matthias Schmidt <matthias@dragonflybsd.org>, University of Marburg,
	6	* Germany.
	7	*
	8	* Redistribution and use in source and binary forms, with or without
	9	* modification, are permitted provided that the following conditions
	10	* are met:
	11	*
	12	* 1. Redistributions of source code must retain the above copyright
	13	* notice, this list of conditions and the following disclaimer.
	14	* 2. Redistributions in binary form must reproduce the above copyright
	15	* notice, this list of conditions and the following disclaimer in
	16	* the documentation and/or other materials provided with the
	17	* distribution.
	18	* 3. Neither the name of The DragonFly Project nor the names of its
	19	* contributors may be used to endorse or promote products derived
	20	* from this software without specific, prior written permission.
	21	*
	22	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	23	* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	24	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
	25	* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
	26	* COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
	27	* INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
	28	* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
	29	* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
	30	* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
	31	* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
	32	* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	33	* SUCH DAMAGE.
	34	*
bf28fcc6	35	* $DragonFly: src/libexec/dma/crypto.c,v 1.3 2008/09/02 15:11:49 matthias Exp $
86e4d161 MS	36	*/
	37
	38	#ifdef HAVE_CRYPTO
	39
	40	#include <openssl/x509.h>
bf28fcc6	41	#include <openssl/md5.h>
86e4d161 MS	42	#include <openssl/ssl.h>
	43	#include <openssl/err.h>
	44	#include <openssl/pem.h>
	45	#include <openssl/rand.h>
	46
	47	#include <syslog.h>
	48
	49	#include "dma.h"
	50
	51	extern struct config *config;
	52
	53	static int
	54	init_cert_file(struct qitem it, SSL_CTX ctx, const char *path)
	55	{
	56	int error;
	57
	58	/* Load certificate into ctx */
	59	error = SSL_CTX_use_certificate_chain_file(ctx, path);
	60	if (error < 1) {
	61	syslog(LOG_ERR, "%s: SSL: Cannot load certificate: %s",
	62	it->queueid, path);
	63	return (-1);
	64	}
	65
	66	/* Add private key to ctx */
	67	error = SSL_CTX_use_PrivateKey_file(ctx, path, SSL_FILETYPE_PEM);
	68	if (error < 1) {
	69	syslog(LOG_ERR, "%s: SSL: Cannot load private key: %s",
	70	it->queueid, path);
	71	return (-1);
	72	}
	73
	74	/*
	75	* Check the consistency of a private key with the corresponding
	76	* certificate
	77	*/
	78	error = SSL_CTX_check_private_key(ctx);
	79	if (error < 1) {
	80	syslog(LOG_ERR, "%s: SSL: Cannot check private key: %s",
	81	it->queueid, path);
	82	return (-1);
	83	}
	84
	85	return (0);
	86	}
	87
	88	int
	89	smtp_init_crypto(struct qitem *it, int fd, int feature)
	90	{
	91	SSL_CTX *ctx = NULL;
	92	SSL_METHOD *meth = NULL;
	93	X509 *cert;
	94	char buf[2048];
	95	int error;
	96
	97	/* Init SSL library */
	98	SSL_library_init();
	99
	100	meth = TLSv1_client_method();
	101
	102	ctx = SSL_CTX_new(meth);
	103	if (ctx == NULL) {
	104	syslog(LOG_ERR, "%s: remote delivery deferred:"
	105	" SSL init failed: %m", it->queueid);
106	return (2);
107	}
108
109	/* User supplied a certificate */
110	if (config->certfile != NULL)
111	init_cert_file(it, ctx, config->certfile);
112
113	/*
114	* If the user wants STARTTLS, we have to send EHLO here
115	*/
116	if (((feature & SECURETRANS) != 0) &&
117	(feature & STARTTLS) != 0) {
118	/* TLS init phase, disable SSL_write */
50c8e68a	119	config->features \|= NOSSL;
86e4d161 MS	120
86e4d161 MS	121	send_remote_command(fd, "EHLO %s", hostname());
bf28fcc6	122	if (read_remote(fd, 0, NULL) == 2) {
86e4d161	123	send_remote_command(fd, "STARTTLS");
bf28fcc6	124	if (read_remote(fd, 0, NULL) != 2) {
86e4d161 MS	125	syslog(LOG_ERR, "%s: remote delivery failed:"
86e4d161 MS	126	" STARTTLS not available: %m", it->queueid);
50c8e68a	127	config->features &= ~NOSSL;
86e4d161 MS	128	return (-1);
	129	}
	130	}
	131	/* End of TLS init phase, enable SSL_write/read */
50c8e68a	132	config->features &= ~NOSSL;
86e4d161 MS	133	}
	134
	135	config->ssl = SSL_new(ctx);
	136	if (config->ssl == NULL) {
	137	syslog(LOG_ERR, "%s: remote delivery deferred:"
	138	" SSL struct creation failed:", it->queueid);
	139	return (2);
	140	}
	141
	142	/* Set ssl to work in client mode */
	143	SSL_set_connect_state(config->ssl);
	144
	145	/* Set fd for SSL in/output */
	146	error = SSL_set_fd(config->ssl, fd);
	147	if (error == 0) {
	148	error = SSL_get_error(config->ssl, error);
	149	syslog(LOG_ERR, "%s: remote delivery deferred:"
	150	" SSL set fd failed (%d): %m", it->queueid, error);
	151	return (2);
	152	}
	153
	154	/* Open SSL connection */
	155	error = SSL_connect(config->ssl);
	156	if (error < 0) {
	157	syslog(LOG_ERR, "%s: remote delivery failed:"
	158	" SSL handshake fataly failed: %m", it->queueid);
	159	return (-1);
	160	}
	161
	162	/* Get peer certificate */
	163	cert = SSL_get_peer_certificate(config->ssl);
	164	if (cert == NULL) {
	165	syslog(LOG_ERR, "%s: remote delivery deferred:"
	166	" Peer did not provied certificate: %m", it->queueid);
	167	}
	168	X509_free(cert);
	169
	170	return (0);
	171	}
	172
bf28fcc6 MS	173	/*
	174	* hmac_md5() taken out of RFC 2104. This RFC was written by H. Krawczyk,
	175	* M. Bellare and R. Canetti.
	176	*/
	177	void
	178	hmac_md5(text, text_len, key, key_len, digest)
	179	unsigned char* text; /* pointer to data stream */
	180	int text_len; /* length of data stream */
	181	unsigned char* key; /* pointer to authentication key */
	182	int key_len; /* length of authentication key */
	183	caddr_t digest; /* caller digest to be filled in */
	184
	185	{
	186	MD5_CTX context;
	187	unsigned char k_ipad[65]; /* inner padding -
	188	* key XORd with ipad
	189	*/
	190	unsigned char k_opad[65]; /* outer padding -
	191	* key XORd with opad
	192	*/
	193	unsigned char tk[16];
	194	int i;
	195	/* if key is longer than 64 bytes reset it to key=MD5(key) */
	196	if (key_len > 64) {
	197
	198	MD5_CTX tctx;
	199
	200	MD5_Init(&tctx);
	201	MD5_Update(&tctx, key, key_len);
	202	MD5_Final(tk, &tctx);
	203
	204	key = tk;
	205	key_len = 16;
	206	}
	207
	208	/*
	209	* the HMAC_MD5 transform looks like:
	210	*
	211	* MD5(K XOR opad, MD5(K XOR ipad, text))
	212	*
	213	* where K is an n byte key
	214	* ipad is the byte 0x36 repeated 64 times
	215	*
	216	* opad is the byte 0x5c repeated 64 times
	217	* and text is the data being protected
	218	*/
	219
	220	/* start out by storing key in pads */
	221	bzero( k_ipad, sizeof k_ipad);
	222	bzero( k_opad, sizeof k_opad);
	223	bcopy( key, k_ipad, key_len);
	224	bcopy( key, k_opad, key_len);
	225
	226	/* XOR key with ipad and opad values */
	227	for (i=0; i<64; i++) {
	228	k_ipad[i] ^= 0x36;
	229	k_opad[i] ^= 0x5c;
	230	}
	231	/*
	232	* perform inner MD5
	233	*/
	234	MD5_Init(&context); /* init context for 1st
	235	* pass */
	236	MD5_Update(&context, k_ipad, 64); /* start with inner pad */
237	MD5_Update(&context, text, text_len); /* then text of datagram */
238	MD5_Final(digest, &context); /* finish up 1st pass */
239	/*
240	* perform outer MD5
241	*/
242	MD5_Init(&context); /* init context for 2nd
243	* pass */
244	MD5_Update(&context, k_opad, 64); /* start with outer pad */
245	MD5_Update(&context, digest, 16); /* then results of 1st
246	* hash */
247	MD5_Final(digest, &context); /* finish up 2nd pass */
248	}
249
86e4d161 MS	250	/*
86e4d161 MS	251	* CRAM-MD5 authentication
86e4d161 MS	252	*/
86e4d161 MS	253	int
bf28fcc6	254	smtp_auth_md5(struct qitem it, int fd, char login, char *password)
86e4d161	255	{
bf28fcc6 MS	256	unsigned char buffer[BUF_SIZE], digest[BUF_SIZE], ascii_digest[33];
	257	char *temp;
	258	int len, i;
	259	static char hextab[] = "0123456789abcdef";
	260
	261	temp = calloc(BUF_SIZE, 1);
	262	memset(buffer, 0, sizeof(buffer));
	263	memset(digest, 0, sizeof(digest));
	264	memset(ascii_digest, 0, sizeof(ascii_digest));
	265
	266	/* Send AUTH command according to RFC 2554 */
	267	send_remote_command(fd, "AUTH CRAM-MD5");
	268	if (read_remote(fd, sizeof(buffer), buffer) != 3) {
	269	syslog(LOG_ERR, "%s: smarthost authentification:"
	270	" AUTH cram-md5 not available: %m", it->queueid);
	271	/* if cram-md5 is not available */
	272	return (-1);
	273	}
	274
	275	/* skip 3 char status + 1 char space */
	276	base64_decode(buffer + 4, temp);
	277	hmac_md5(temp, strlen(temp), password, strlen(password), digest);
	278
	279	ascii_digest[32] = 0;
	280	for (i = 0; i < 16; i++) {
	281	ascii_digest[2*i] = hextab[digest[i] >> 4];
	282	ascii_digest[2*i+1] = hextab[digest[i] & 15];
	283	}
	284
	285	/* prepare answer */
	286	snprintf(buffer, BUF_SIZE, "%s %s", login, ascii_digest);
	287
	288	/* temp will be allocated inside base64_encode again */
	289	free(temp);
	290	/* encode answer */
	291	len = base64_encode(buffer, strlen(buffer), &temp);
	292	if (len <= 0)
	293	return (-1);
	294
	295	/* send answer */
	296	send_remote_command(fd, "%s", temp);
	297	if (read_remote(fd, 0, NULL) != 2) {
	298	syslog(LOG_ERR, "%s: remote delivery deferred:"
	299	" AUTH cram-md5 failed: %m", it->queueid);
	300	return (-2);
	301	}
	302
	303	return (0);
86e4d161	304	}
86e4d161 MS	305
86e4d161 MS	306	#endif /* HAVE_CRYPTO */