/*
- * imap.c -- IMAP2bis protocol methods
+ * 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 "socket.h"
+#include <ctype.h>
+#if defined(STDC_HEADERS)
+#include <stdlib.h>
+#endif
#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 */
+#define IMAP2 -1 /* IMAP2 or IMAP2BIS, RFC1176 */
+#define IMAP4 0 /* IMAP4 rev 0, RFC1730 */
+#define IMAP4rev1 1 /* IMAP4 rev 1, RFC2060 */
-static int count, seen;
+static int count, seen, recent, unseen, deletecount, imap_version;
-int imap_ok (socket, argbuf)
+int imap_ok(int sock, char *argbuf)
/* parse command response */
-char *argbuf;
-int socket;
{
- int ok;
char buf [POPBUFSIZE+1];
- char *bufp;
- int n;
seen = 0;
do {
- if (SockGets(socket, buf, sizeof(buf)) < 0)
- return(PS_SOCKET);
+ int ok;
- if (outlevel == O_VERBOSE)
- fprintf(stderr,"%s\n",buf);
+ if ((ok = gen_recv(sock, buf, sizeof(buf))))
+ return(ok);
/* interpret untagged status responses */
if (strstr(buf, "EXISTS"))
count = atoi(buf+2);
+ if (strstr(buf, "RECENT"))
+ recent = atoi(buf+2);
+ if (strstr(buf, "UNSEEN"))
+ {
+ 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);
- return(0);
+ if (argbuf)
+ strcpy(argbuf, buf);
+ return(PS_SUCCESS);
}
else
{
if (strncmp(cp, "OK", 2) == 0)
{
- strcpy(argbuf, cp);
- return(0);
+ if (argbuf)
+ strcpy(argbuf, cp);
+ return(PS_SUCCESS);
}
else if (strncmp(cp, "BAD", 2) == 0)
return(PS_ERROR);
}
}
-int imap_getauth(socket, queryctl, buf)
+#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 */
+{
+ 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.
+ */
+
+ if (result = gen_recv(sock, buf1, sizeof buf1)) {
+ return result;
+ }
+
+ len = from64tobits(challenge1.cstr, buf1);
+ if (len < 0) {
+ error(0, -1, "could not decode initial BASE64 challenge");
+ return PS_AUTHFAIL;
+ }
+
+ /* 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);
+ }
+ }
+
+ strncpy(srvrealm, krb_realmofhost(srvinst), (sizeof srvrealm)-1);
+ srvrealm[(sizeof srvrealm)-1] = '\0';
+ if (p = strchr(srvinst, '.')) {
+ *p = '\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;
+ }
+
+ 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;
+ }
+
+ 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 */
-int socket;
-struct hostrec *queryctl;
-char *buf;
{
- /* try to get authorized */
- return(gen_transact(socket,
- "LOGIN %s \"%s\"",
- queryctl->remotename, queryctl->password));
+ 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 imap_getrange(socket, queryctl, countp)
+static int imap_getrange(int sock,
+ struct query *ctl,
+ const char *folder,
+ int *countp, int *newp)
/* get range of messages to be fetched */
-int socket;
-struct hostrec *queryctl;
-int *countp;
{
int ok;
/* find out how many messages are waiting */
- ok = gen_transact(socket,
- "SELECT %s",
- queryctl->mailbox[0] ? queryctl->mailbox : "INBOX");
+ recent = unseen = -1;
+ ok = gen_transact(sock, "SELECT %s", folder ? folder : "INBOX");
if (ok != 0)
+ {
+ error(0, 0, "mailbox selection failed");
return(ok);
+ }
*countp = count;
- return(0);
+ /*
+ * 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 */
+
+ deletecount = 0;
+
+ return(PS_SUCCESS);
}
-static imap_is_old(socket, queryctl, num)
-int socket;
-struct hostrec *queryctl;
-int num;
+static int imap_getsizes(int sock, int count, int *sizes)
+/* capture the sizes of all messages */
{
char buf [POPBUFSIZE+1];
+
+ gen_send(sock, "FETCH 1:%d RFC822.SIZE", count);
+ for (;;)
+ {
+ int num, size, ok;
+
+ if ((ok = gen_recv(sock, buf, sizeof(buf))))
+ return(ok);
+ if (strstr(buf, "OK"))
+ break;
+ else if (sscanf(buf, "* %d FETCH (RFC822.SIZE %d)", &num, &size) == 2)
+ sizes[num - 1] = size;
+ else
+ sizes[num - 1] = -1;
+ }
+
+ return(PS_SUCCESS);
+}
+
+static int imap_is_old(int sock, struct query *ctl, int number)
+/* is the given message old? */
+{
int ok;
- if ((ok = gen_transact(socket, "FETCH %d FLAGS", num)) != 0)
- exit(PS_ERROR);
+ /* expunges change the fetch numbers */
+ number -= deletecount;
+
+ if ((ok = gen_transact(sock, "FETCH %d FLAGS", number)) != 0)
+ return(PS_ERROR);
return(seen);
}
-static int imap_fetch(socket, number, lenp)
-/* request nth message */
-int socket;
-int number;
-int *lenp;
+static int imap_fetch_headers(int sock, struct query *ctl,int number,int *lenp)
+/* request headers of nth message */
{
char buf [POPBUFSIZE+1];
int num;
- gen_send(socket, "FETCH %d RFC822", number);
+ /* expunges change the fetch numbers */
+ number -= deletecount;
+
+ /*
+ * This is blessed by RFC 1176, RFC1730, RFC2060.
+ * According to the RFCs, it should *not* set the \Seen flag.
+ */
+ gen_send(sock, "FETCH %d RFC822.HEADER", number);
/* looking for FETCH response */
do {
- if (SockGets(socket, buf,sizeof(buf)) < 0)
- return(PS_SOCKET);
+ int ok;
+
+ if ((ok = gen_recv(sock, buf, sizeof(buf))))
+ return(ok);
} while
- (sscanf(buf+2, "%d FETCH (RFC822 {%d}", &num, lenp) != 2);
+ (sscanf(buf+2, "%d FETCH (%*s {%d}", &num, lenp) != 2);
if (num != number)
return(PS_ERROR);
else
- return(0);
+ return(PS_SUCCESS);
}
-static imap_trail(socket, queryctl, number)
-/* discard tail of FETCH response */
-int socket;
-struct hostrec *queryctl;
-int number;
+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 */
+ number -= deletecount;
+
+ /*
+ * If we're using IMAP4, we can fetch the message without setting its
+ * seen flag. This is good! It means that if the protocol exchange
+ * craps out during the message, it will still be marked `unseen' on
+ * the server.
+ *
+ * However...*don't* do this if we're using keep to suppress deletion!
+ * In that case, marking the seen flag is the only way to prevent the
+ * message from being re-fetched on subsequent runs.
+ */
+ switch (imap_version)
+ {
+ case IMAP4rev1: /* RFC 2060 */
+ if (!ctl->keep)
+ gen_send(sock, "FETCH %d BODY.PEEK[TEXT]", number);
+ else
+ gen_send(sock, "FETCH %d BODY[TEXT]", number);
+ break;
+
+ case IMAP4: /* RFC 1730 */
+ if (!ctl->keep)
+ gen_send(sock, "FETCH %d RFC822.TEXT.PEEK", number);
+ else
+ gen_send(sock, "FETCH %d RFC822.TEXT", number);
+ break;
+
+ default: /* RFC 1176 */
+ gen_send(sock, "FETCH %d RFC822.TEXT", number);
+ break;
+ }
+
+ /* looking for FETCH response */
+ do {
+ int ok;
- if (SockGets(socket, buf,sizeof(buf)) < 0)
- return(PS_SOCKET);
+ if ((ok = gen_recv(sock, buf, sizeof(buf))))
+ return(ok);
+ } while
+ (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(0);
+ *lenp = 0;
+
+ return(PS_SUCCESS);
}
-static imap_delete(socket, queryctl, number)
+static int imap_trail(int sock, struct query *ctl, int number)
+/* discard tail of FETCH response after reading message text */
+{
+ /* expunges change the fetch numbers */
+ /* number -= deletecount; */
+
+ 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)
/* set delete flag for given message */
-int socket;
-struct hostrec *queryctl;
-int number;
{
+ int ok;
+
+ /* expunges change the fetch numbers */
+ number -= deletecount;
+
+ /*
+ * Use SILENT if possible as a minor throughput optimization.
+ * Note: this has been dropped from IMAP4rev1.
+ */
+ if ((ok = gen_transact(sock,
+ imap_version == IMAP4
+ ? "STORE %d +FLAGS.SILENT (\\Deleted)"
+ : "STORE %d +FLAGS (\\Deleted)",
+ number)))
+ return(ok);
+
/*
- * I think the SILENT modifier here is the only thing keeping this code
- * from being IMAP2 (RFC 1176-compliant), rather than IMAP2bis. It's
- * important for places where phone service is expensive to cut the
- * IMAP protocol overhead as much as possible.
+ * We do an expunge after each message, rather than just before quit,
+ * so that a line hit during a long session won't result in lots of
+ * messages being fetched again during the next session.
*/
- return(gen_transact(socket, "STORE %d +FLAGS.SILENT (\\Deleted)", number));
+ if ((ok = gen_transact(sock, "EXPUNGE")))
+ return(ok);
+
+ deletecount++;
+
+ return(PS_SUCCESS);
}
const static struct method imap =
{
"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, /* get sizes of messages (used for --limit option */
imap_is_old, /* no UID check */
- imap_fetch, /* request given message */
+ imap_fetch_headers, /* request given message headers */
+ imap_fetch_body, /* request given message body */
imap_trail, /* eat message trailer */
- imap_delete, /* set IMAP delete flag */
- "EXPUNGE", /* the IMAP expunge command */
+ imap_delete, /* delete the message */
"LOGOUT", /* the IMAP exit command */
};
-int doIMAP (queryctl)
+int doIMAP(struct query *ctl)
/* retrieve messages using IMAP Version 2bis or Version 4 */
-struct hostrec *queryctl;
{
- return(do_protocol(queryctl, &imap));
+ return(do_protocol(ctl, &imap));
}
/* imap.c ends here */
projects / ~andy / fetchmail / blobdiff