/*
* imap.c -- IMAP2bis/IMAP4 protocol methods
*
- * Copyright 1996 by Eric S. Raymond
- * All rights reserved.
+ * Copyright 1997 by Eric S. Raymond
* For license terms, see the file COPYING in this directory.
*/
-#include <config.h>
+#include "config.h"
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include "fetchmail.h"
#include "socket.h"
+#ifdef KERBEROS_V4
+#if defined (__bsdi__)
+#include <des.h>
+#define krb_get_err_text(e) (krb_err_txt[e])
+#endif
+#if defined (__FreeBSD__)
+#define krb_get_err_text(e) (krb_err_txt[e])
+#endif
+#include <krb.h>
+#endif /* KERBEROS_V4 */
+
extern char *strstr(); /* needed on sysV68 R3V7.1. */
/* imap_version values */
static int count, seen, recent, unseen, deletecount, imap_version;
-int imap_ok (int sock, char *argbuf)
+int imap_ok(int sock, char *argbuf)
/* parse command response */
{
char buf [POPBUFSIZE+1];
if (strstr(buf, "RECENT"))
recent = atoi(buf+2);
if (strstr(buf, "UNSEEN"))
- unseen = atoi(buf+2);
+ {
+ char *cp;
+
+ /*
+ * Handle both "* 42 UNSEEN" (if tha ever happens) and
+ * "* OK [UNSEEN 42] 42". Note that what this gets us is
+ * a minimum index, not a count.
+ */
+ unseen = 0;
+ for (cp = buf; *cp && !isdigit(*cp); cp++)
+ continue;
+ unseen = atoi(cp);
+ }
if (strstr(buf, "FLAGS"))
seen = (strstr(buf, "Seen") != (char *)NULL);
} while
if (tag[0] == '\0')
{
- strcpy(argbuf, buf);
+ if (argbuf)
+ strcpy(argbuf, buf);
return(PS_SUCCESS);
}
else
if (strncmp(cp, "OK", 2) == 0)
{
- strcpy(argbuf, cp);
+ if (argbuf)
+ strcpy(argbuf, cp);
return(PS_SUCCESS);
}
else if (strncmp(cp, "BAD", 2) == 0)
}
}
-int imap_getauth(int sock, struct query *ctl, char *buf)
-/* apply for connection authorization */
+#ifdef KERBEROS_V4
+#if SIZEOF_INT == 4
+typedef int int32;
+#elif SIZEOF_SHORT == 4
+typedef short int32;
+#elif SIZEOF_LONG == 4
+typedef long int32;
+#else
+#error Cannot deduce a 32-bit-type
+#endif
+
+static int do_rfc1731(int sock, struct query *ctl, char *buf)
+/* authenticate as per RFC1731 -- note 32-bit integer requirement here */
{
- char rbuf [POPBUFSIZE+1];
+ int result = 0, len;
+ char buf1[4096], buf2[4096];
+ union {
+ int32 cint;
+ char cstr[4];
+ } challenge1, challenge2;
+ char srvinst[INST_SZ];
+ char *p;
+ char srvrealm[REALM_SZ];
+ KTEXT_ST authenticator;
+ CREDENTIALS credentials;
+ char tktuser[MAX_K_NAME_SZ+1+INST_SZ+1+REALM_SZ+1];
+ char tktinst[INST_SZ];
+ char tktrealm[REALM_SZ];
+ des_cblock session;
+ des_key_schedule schedule;
+
+ gen_send(sock, "AUTHENTICATE KERBEROS_V4");
+
+ /* The data encoded in the first ready response contains a random
+ * 32-bit number in network byte order. The client should respond
+ * with a Kerberos ticket and an authenticator for the principal
+ * "imap.hostname@realm", where "hostname" is the first component
+ * of the host name of the server with all letters in lower case
+ * and where "realm" is the Kerberos realm of the server. The
+ * encrypted checksum field included within the Kerberos
+ * authenticator should contain the server provided 32-bit number
+ * in network byte order.
+ */
- /* try to get authorized */
- int ok = gen_transact(sock,
- "LOGIN %s \"%s\"",
- ctl->remotename, ctl->password);
+ if (result = gen_recv(sock, buf1, sizeof buf1)) {
+ return result;
+ }
- if (ok)
- return(ok);
+ len = from64tobits(challenge1.cstr, buf1);
+ if (len < 0) {
+ error(0, -1, "could not decode initial BASE64 challenge");
+ return PS_AUTHFAIL;
+ }
- /* probe to see if we're running IMAP4 and can use RFC822.PEEK */
- gen_send(sock, "CAPABILITY");
- if ((ok = gen_recv(sock, rbuf, sizeof(rbuf))))
- return(ok);
- if (strstr(rbuf, "BAD"))
- {
- imap_version = IMAP2;
- if (outlevel == O_VERBOSE)
- error(0, 0, "Protocol identified as IMAP2 or IMAP2BIS");
+ /* Client responds with a Kerberos ticket and an authenticator for
+ * the principal "imap.hostname@realm" where "hostname" is the
+ * first component of the host name of the server with all letters
+ * in lower case and where "realm" is the Kerberos realm of the
+ * server. The encrypted checksum field included within the
+ * Kerberos authenticator should contain the server-provided
+ * 32-bit number in network byte order.
+ */
+
+ strncpy(srvinst, ctl->server.truename, (sizeof srvinst)-1);
+ srvinst[(sizeof srvinst)-1] = '\0';
+ for (p = srvinst; *p; p++) {
+ if (isupper(*p)) {
+ *p = tolower(*p);
+ }
}
- else if (strstr(rbuf, "IMAP4rev1"))
- {
- imap_version = IMAP4rev1;
- if (outlevel == O_VERBOSE)
- error(0, 0, "Protocol identified as IMAP4 rev 1");
+
+ strncpy(srvrealm, krb_realmofhost(srvinst), (sizeof srvrealm)-1);
+ srvrealm[(sizeof srvrealm)-1] = '\0';
+ if (p = strchr(srvinst, '.')) {
+ *p = '\0';
}
- else
- {
- imap_version = IMAP4;
- if (outlevel == O_VERBOSE)
- error(0, 0, "Protocol identified as IMAP4 rev 0");
+
+ result = krb_mk_req(&authenticator, "imap", srvinst, srvrealm, 0);
+ if (result) {
+ error(0, -1, "krb_mq_req: %s", krb_get_err_text(result));
+ return PS_AUTHFAIL;
}
- peek_capable = (imap_version >= IMAP4);
+ result = krb_get_cred("imap", srvinst, srvrealm, &credentials);
+ if (result) {
+ error(0, -1, "krb_get_cred: %s", krb_get_err_text(result));
+ return PS_AUTHFAIL;
+ }
- return(PS_SUCCESS);
+ memcpy(session, credentials.session, sizeof session);
+ memset(&credentials, 0, sizeof credentials);
+ des_key_sched(session, schedule);
+
+ result = krb_get_tf_fullname(TKT_FILE, tktuser, tktinst, tktrealm);
+ if (result) {
+ error(0, -1, "krb_get_tf_fullname: %s", krb_get_err_text(result));
+ return PS_AUTHFAIL;
+ }
+
+ if (strcmp(tktuser, user) != 0) {
+ error(0, -1, "principal %s in ticket does not match -u %s", tktuser,
+ user);
+ return PS_AUTHFAIL;
+ }
+
+ if (tktinst[0]) {
+ error(0, 0, "non-null instance (%s) might cause strange behavior",
+ tktinst);
+ strcat(tktuser, ".");
+ strcat(tktuser, tktinst);
+ }
+
+ if (strcmp(tktrealm, srvrealm) != 0) {
+ strcat(tktuser, "@");
+ strcat(tktuser, tktrealm);
+ }
+
+ result = krb_mk_req(&authenticator, "imap", srvinst, srvrealm,
+ challenge1.cint);
+ if (result) {
+ error(0, -1, "krb_mq_req: %s", krb_get_err_text(result));
+ return PS_AUTHFAIL;
+ }
+
+ to64frombits(buf1, authenticator.dat, authenticator.length);
+ if (outlevel == O_VERBOSE) {
+ error(0, 0, "IMAP> %s", buf1);
+ }
+ SockWrite(sock, buf1, strlen(buf1));
+ SockWrite(sock, "\r\n", 2);
+
+ /* Upon decrypting and verifying the ticket and authenticator, the
+ * server should verify that the contained checksum field equals
+ * the original server provided random 32-bit number. Should the
+ * verification be successful, the server must add one to the
+ * checksum and construct 8 octets of data, with the first four
+ * octets containing the incremented checksum in network byte
+ * order, the fifth octet containing a bit-mask specifying the
+ * protection mechanisms supported by the server, and the sixth
+ * through eighth octets containing, in network byte order, the
+ * maximum cipher-text buffer size the server is able to receive.
+ * The server must encrypt the 8 octets of data in the session key
+ * and issue that encrypted data in a second ready response. The
+ * client should consider the server authenticated if the first
+ * four octets the un-encrypted data is equal to one plus the
+ * checksum it previously sent.
+ */
+
+ if (result = gen_recv(sock, buf1, sizeof buf1))
+ return result;
+
+ /* The client must construct data with the first four octets
+ * containing the original server-issued checksum in network byte
+ * order, the fifth octet containing the bit-mask specifying the
+ * selected protection mechanism, the sixth through eighth octets
+ * containing in network byte order the maximum cipher-text buffer
+ * size the client is able to receive, and the following octets
+ * containing a user name string. The client must then append
+ * from one to eight octets so that the length of the data is a
+ * multiple of eight octets. The client must then PCBC encrypt the
+ * data with the session key and respond to the second ready
+ * response with the encrypted data. The server decrypts the data
+ * and verifies the contained checksum. The username field
+ * identifies the user for whom subsequent IMAP operations are to
+ * be performed; the server must verify that the principal
+ * identified in the Kerberos ticket is authorized to connect as
+ * that user. After these verifications, the authentication
+ * process is complete.
+ */
+
+ len = from64tobits(buf2, buf1);
+ if (len < 0) {
+ error(0, -1, "could not decode BASE64 ready response");
+ return PS_AUTHFAIL;
+ }
+
+ des_ecb_encrypt((des_cblock *)buf2, (des_cblock *)buf2, schedule, 0);
+ memcpy(challenge2.cstr, buf2, 4);
+ if (ntohl(challenge2.cint) != challenge1.cint + 1) {
+ error(0, -1, "challenge mismatch");
+ return PS_AUTHFAIL;
+ }
+
+ memset(authenticator.dat, 0, sizeof authenticator.dat);
+
+ result = htonl(challenge1.cint);
+ memcpy(authenticator.dat, &result, sizeof result);
+
+ /* The protection mechanisms and their corresponding bit-masks are as
+ * follows:
+ *
+ * 1 No protection mechanism
+ * 2 Integrity (krb_mk_safe) protection
+ * 4 Privacy (krb_mk_priv) protection
+ */
+ authenticator.dat[4] = 1;
+
+ len = strlen(tktuser);
+ strncpy(authenticator.dat+8, tktuser, len);
+ authenticator.length = len + 8 + 1;
+ while (authenticator.length & 7) {
+ authenticator.length++;
+ }
+ des_pcbc_encrypt((des_cblock *)authenticator.dat,
+ (des_cblock *)authenticator.dat, authenticator.length, schedule,
+ &session, 1);
+
+ to64frombits(buf1, authenticator.dat, authenticator.length);
+ if (outlevel == O_VERBOSE) {
+ error(0, 0, "IMAP> %s", buf1);
+ }
+ SockWrite(sock, buf1, strlen(buf1));
+ SockWrite(sock, "\r\n", 2);
+
+ if (result = gen_recv(sock, buf1, sizeof buf1))
+ return result;
+
+ if (strstr(buf1, "OK")) {
+ return PS_SUCCESS;
+ }
+ else {
+ return PS_AUTHFAIL;
+ }
+}
+#endif /* KERBEROS_V4 */
+
+int imap_getauth(int sock, struct query *ctl, char *buf)
+/* apply for connection authorization */
+{
+ char rbuf [POPBUFSIZE+1];
+ int ok = 0;
+#ifdef KERBEROS_V4
+ int kerbok = 0;
+
+ if (ctl->server.protocol != P_IMAP_K4)
+#endif /* KERBEROS_V4 */
+ /* try to get authorized */
+ ok = gen_transact(sock,
+ "LOGIN %s \"%s\"", ctl->remotename, ctl->password);
+
+ if (ok)
+ return(ok);
+
+ /* probe to see if we're running IMAP4 and can use RFC822.PEEK */
+ gen_send(sock, "CAPABILITY");
+ if ((ok = gen_recv(sock, rbuf, sizeof(rbuf))))
+ return(ok);
+ if (strstr(rbuf, "BAD"))
+ {
+ imap_version = IMAP2;
+ if (outlevel == O_VERBOSE)
+ error(0, 0, "Protocol identified as IMAP2 or IMAP2BIS");
+ }
+ /* UW-IMAP server 10.173 notifies in all caps */
+ else if (strstr(rbuf, "IMAP4rev1") || strstr(rbuf, "IMAP4REV1"))
+ {
+ imap_version = IMAP4rev1;
+ if (outlevel == O_VERBOSE)
+ error(0, 0, "Protocol identified as IMAP4 rev 1");
+ }
+ else
+ {
+ imap_version = IMAP4;
+ if (outlevel == O_VERBOSE)
+ error(0, 0, "Protocol identified as IMAP4 rev 0");
+ }
+
+ /* eat the tail of the CAPABILITY response (if any) */
+ if ((peek_capable = (imap_version >= IMAP4)))
+ if ((ok = imap_ok(sock, (char *)NULL)))
+ return(ok);
+
+#ifdef KERBEROS_V4
+ if (strstr(rbuf, "AUTH=KERBEROS_V4"))
+ {
+ kerbok++;
+ if (outlevel == O_VERBOSE)
+ error(0, 0, "KERBEROS_V4 authentication is supported");
+ }
+
+ /* eat OK response */
+ if ((ok = gen_recv(sock, rbuf, sizeof(rbuf))))
+ return(ok);
+
+ if (!strstr(rbuf, "OK"))
+ return(PS_AUTHFAIL);
+
+ if ((imap_version >= IMAP4) && (ctl->server.protocol == P_IMAP_K4))
+ {
+ if (!kerbok)
+ {
+ error(0, -1, "Required KERBEROS_V4 capability not supported by server");
+ return(PS_AUTHFAIL);
+ }
+
+ if ((ok = do_rfc1731(sock, ctl, buf)))
+ {
+ if (outlevel == O_VERBOSE)
+ error(0, 0, "IMAP> *");
+ SockWrite(sock, "*\r\n", 3);
+ return(ok);
+ }
+ }
+#endif /* KERBEROS_V4 */
+
+ return(PS_SUCCESS);
}
static int imap_getrange(int sock,
int ok;
/* find out how many messages are waiting */
- recent = unseen = 0;
+ recent = unseen = -1;
ok = gen_transact(sock, "SELECT %s", folder ? folder : "INBOX");
if (ok != 0)
{
*countp = count;
- if (unseen) /* optional response, but better if we see it */
- *newp = unseen;
- else if (recent) /* mandatory */
+ /*
+ * Note: because IMAP has an is_old method, this number is used
+ * only for the "X messages (Y unseen)" notification. Accordingly
+ * it doesn't matter much that it can be wrong (e.g. if we see an
+ * UNSEEN response but not all messages above the first UNSEEN one
+ * are likewise).
+ */
+ if (unseen >= 0) /* optional, but better if we see it */
+ *newp = count - unseen + 1;
+ else if (recent >= 0) /* mandatory */
*newp = recent;
else
- *newp = -1; /* should never happen, RECENT is mandatory */
+ *newp = -1; /* should never happen, RECENT is mandatory */
deletecount = 0;
char buf [POPBUFSIZE+1];
gen_send(sock, "FETCH 1:%d RFC822.SIZE", count);
- while (SockRead(sock, buf, sizeof(buf)))
+ for (;;)
{
int num, size, ok;
static int imap_fetch_body(int sock, struct query *ctl, int number, int *lenp)
/* request body of nth message */
{
- char buf [POPBUFSIZE+1];
+ char buf [POPBUFSIZE+1], *cp;
int num;
/* expunges change the fetch numbers */
if ((ok = gen_recv(sock, buf, sizeof(buf))))
return(ok);
} while
- /* third token can be "RFC822" or "BODY[]" */
- (sscanf(buf+2, "%d FETCH (%*s {%d}", &num, lenp) != 2);
+ (sscanf(buf+2, "%d FETCH", &num) != 1);
if (num != number)
return(PS_ERROR);
+
+ /* try to extract a length */
+ if ((cp = strchr(buf, '{')))
+ *lenp = atoi(cp + 1);
else
- return(PS_SUCCESS);
+ *lenp = 0;
+
+ return(PS_SUCCESS);
}
static int imap_trail(int sock, struct query *ctl, int number)
/* discard tail of FETCH response after reading message text */
{
- char buf [POPBUFSIZE+1];
-
/* expunges change the fetch numbers */
/* number -= deletecount; */
- return(gen_recv(sock, buf, sizeof(buf)));
+ for (;;)
+ {
+ char buf[POPBUFSIZE+1];
+ int ok;
+
+ if ((ok = gen_recv(sock, buf, sizeof(buf))))
+ return(ok);
+
+ /* UW IMAP returns "OK FETCH", Cyrus returns "OK Completed" */
+ if (strstr(buf, "OK"))
+ break;
+ }
+
+ return(PS_SUCCESS);
}
static int imap_delete(int sock, struct query *ctl, int number)
{
"IMAP", /* Internet Message Access Protocol */
143, /* standard IMAP2bis/IMAP4 port */
- 1, /* this is a tagged protocol */
- 0, /* no message delimiter */
+ TRUE, /* this is a tagged protocol */
+ FALSE, /* no message delimiter */
imap_ok, /* parse command response */
imap_getauth, /* get authorization */
imap_getrange, /* query range of messages */
- imap_getsizes, /* grab message sizes */
+ imap_getsizes, /* get sizes of messages (used for --limit option */
imap_is_old, /* no UID check */
imap_fetch_headers, /* request given message headers */
imap_fetch_body, /* request given message body */
projects / ~andy / fetchmail / blobdiff