* Exim - an Internet mail transport agent *
*************************************************/
-/* Copyright (c) University of Cambridge, 1995 - 2016 */
+/* Copyright (c) University of Cambridge, 1995 - 2017 */
/* See the file NOTICE for conditions of use and distribution. */
/* Code for DKIM support. Other DKIM relevant code is in
pdkim_ctx *dkim_verify_ctx = NULL;
pdkim_signature *dkim_signatures = NULL;
pdkim_signature *dkim_cur_sig = NULL;
+static const uschar * dkim_collect_error = NULL;
static int
dkim_exim_query_dns_txt(char *name, char *answer)
lookup_dnssec_authenticated = NULL;
if (dns_lookup(&dnsa, US name, T_TXT, NULL) != DNS_SUCCEED)
- return PDKIM_FAIL;
+ return PDKIM_FAIL; /*XXX better error detail? logging? */
/* Search for TXT record */
rr_offset += len;
answer_offset += len;
if (answer_offset >= PDKIM_DNS_TXT_MAX_RECLEN)
- return PDKIM_FAIL;
+ return PDKIM_FAIL; /*XXX better error detail? logging? */
}
return PDKIM_OK;
}
-return PDKIM_FAIL;
+return PDKIM_FAIL; /*XXX better error detail? logging? */
}
void
-dkim_exim_verify_init(void)
+dkim_exim_verify_init(BOOL dot_stuffing)
{
/* There is a store-reset between header & body reception
so cannot use the main pool. Any allocs done by Exim
/* Create new context */
-dkim_verify_ctx = pdkim_init_verify(&dkim_exim_query_dns_txt);
+dkim_verify_ctx = pdkim_init_verify(&dkim_exim_query_dns_txt, dot_stuffing);
dkim_collect_input = !!dkim_verify_ctx;
+dkim_collect_error = NULL;
/* Start feed up with any cached data */
receive_get_cache();
void
dkim_exim_verify_feed(uschar * data, int len)
{
+int rc;
+
store_pool = POOL_PERM;
if ( dkim_collect_input
- && pdkim_feed(dkim_verify_ctx, (char *)data, len) != PDKIM_OK)
+ && (rc = pdkim_feed(dkim_verify_ctx, data, len)) != PDKIM_OK)
+ {
+ dkim_collect_error = pdkim_errstr(rc);
+ log_write(0, LOG_MAIN,
+ "DKIM: validation error: %.100s", dkim_collect_error);
dkim_collect_input = FALSE;
+ }
store_pool = dkim_verify_oldpool;
}
void
dkim_exim_verify_finish(void)
{
-pdkim_signature *sig = NULL;
-int dkim_signers_size = 0;
-int dkim_signers_ptr = 0;
-dkim_signers = NULL;
+pdkim_signature * sig = NULL;
+int dkim_signers_size = 0, dkim_signers_ptr = 0, rc;
+const uschar * errstr;
store_pool = POOL_PERM;
/* Delete eventual previous signature chain */
+dkim_signers = NULL;
dkim_signatures = NULL;
-/* If we have arrived here with dkim_collect_input == FALSE, it
-means there was a processing error somewhere along the way.
-Log the incident and disable futher verification. */
-
-if (!dkim_collect_input)
+if (dkim_collect_error)
{
log_write(0, LOG_MAIN,
- "DKIM: Error while running this message through validation,"
- " disabling signature verification.");
+ "DKIM: Error during validation, disabling signature verification: %.100s",
+ dkim_collect_error);
dkim_disable_verify = TRUE;
goto out;
}
/* Finish DKIM operation and fetch link to signatures chain */
-if (pdkim_feed_finish(dkim_verify_ctx, &dkim_signatures) != PDKIM_OK)
+rc = pdkim_feed_finish(dkim_verify_ctx, &dkim_signatures, &errstr);
+if (rc != PDKIM_OK)
+ {
+ log_write(0, LOG_MAIN, "DKIM: validation error: %.100s%s%s", pdkim_errstr(rc),
+ errstr ? ": " : "", errstr ? errstr : US"");
goto out;
+ }
for (sig = dkim_signatures; sig; sig = sig->next)
{
- int size = 0;
- int ptr = 0;
+ int size = 0, ptr = 0;
+ uschar * logmsg = NULL, * s;
/* Log a line for each signature */
- uschar *logmsg = string_append(NULL, &size, &ptr, 5,
- string_sprintf("d=%s s=%s c=%s/%s a=%s b=%d ",
- sig->domain,
- sig->selector,
- sig->canon_headers == PDKIM_CANON_SIMPLE ? "simple" : "relaxed",
- sig->canon_body == PDKIM_CANON_SIMPLE ? "simple" : "relaxed",
- sig->algo == PDKIM_ALGO_RSA_SHA256
- ? "rsa-sha256"
- : sig->algo == PDKIM_ALGO_RSA_SHA1 ? "rsa-sha1" : "err",
- (int)sig->sigdata.len > -1 ? sig->sigdata.len * 8 : 0
- ),
-
- sig->identity ? string_sprintf("i=%s ", sig->identity) : US"",
- sig->created > 0 ? string_sprintf("t=%lu ", sig->created) : US"",
- sig->expires > 0 ? string_sprintf("x=%lu ", sig->expires) : US"",
- sig->bodylength > -1 ? string_sprintf("l=%lu ", sig->bodylength) : US""
- );
+ if (!(s = sig->domain)) s = US"<UNSET>";
+ logmsg = string_append(logmsg, &size, &ptr, 2, "d=", s);
+ if (!(s = sig->selector)) s = US"<UNSET>";
+ logmsg = string_append(logmsg, &size, &ptr, 2, " s=", s);
+ logmsg = string_append(logmsg, &size, &ptr, 7,
+ " c=", sig->canon_headers == PDKIM_CANON_SIMPLE ? "simple" : "relaxed",
+ "/", sig->canon_body == PDKIM_CANON_SIMPLE ? "simple" : "relaxed",
+ " a=", sig->algo == PDKIM_ALGO_RSA_SHA256
+ ? "rsa-sha256"
+ : sig->algo == PDKIM_ALGO_RSA_SHA1 ? "rsa-sha1" : "err",
+ string_sprintf(" b=%d",
+ (int)sig->sighash.len > -1 ? sig->sighash.len * 8 : 0));
+ if ((s= sig->identity)) logmsg = string_append(logmsg, &size, &ptr, 2, " i=", s);
+ if (sig->created > 0) logmsg = string_append(logmsg, &size, &ptr, 1,
+ string_sprintf(" t=%lu", sig->created));
+ if (sig->expires > 0) logmsg = string_append(logmsg, &size, &ptr, 1,
+ string_sprintf(" x=%lu", sig->expires));
+ if (sig->bodylength > -1) logmsg = string_append(logmsg, &size, &ptr, 1,
+ string_sprintf(" l=%lu", sig->bodylength));
switch (sig->verify_status)
{
case PDKIM_VERIFY_NONE:
- logmsg = string_append(logmsg, &size, &ptr, 1, "[not verified]");
+ logmsg = string_append(logmsg, &size, &ptr, 1, " [not verified]");
break;
case PDKIM_VERIFY_INVALID:
- logmsg = string_append(logmsg, &size, &ptr, 1, "[invalid - ");
+ logmsg = string_append(logmsg, &size, &ptr, 1, " [invalid - ");
switch (sig->verify_ext_status)
{
case PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE:
case PDKIM_VERIFY_FAIL:
logmsg =
- string_append(logmsg, &size, &ptr, 1, "[verification failed - ");
+ string_append(logmsg, &size, &ptr, 1, " [verification failed - ");
switch (sig->verify_ext_status)
{
case PDKIM_VERIFY_FAIL_BODY:
case PDKIM_VERIFY_PASS:
logmsg =
- string_append(logmsg, &size, &ptr, 1, "[verification succeeded]");
+ string_append(logmsg, &size, &ptr, 1, " [verification succeeded]");
break;
}
/* Build a colon-separated list of signing domains (and identities, if present) in dkim_signers */
- dkim_signers = string_append(dkim_signers,
- &dkim_signers_size,
- &dkim_signers_ptr, 2, sig->domain, ":");
+ if (sig->domain)
+ dkim_signers = string_append_listele(dkim_signers, &dkim_signers_size,
+ &dkim_signers_ptr, ':', sig->domain);
if (sig->identity)
- dkim_signers = string_append(dkim_signers,
- &dkim_signers_size,
- &dkim_signers_ptr, 2, sig->identity, ":");
+ dkim_signers = string_append_listele(dkim_signers, &dkim_signers_size,
+ &dkim_signers_ptr, ':', sig->identity);
/* Process next signature */
}
-/* NULL-terminate and chop the last colon from the domain list */
-
-if (dkim_signers)
- {
- dkim_signers[dkim_signers_ptr] = '\0';
- if (Ustrlen(dkim_signers) > 0)
- dkim_signers[Ustrlen(dkim_signers) - 1] = '\0';
- }
-
out:
store_pool = dkim_verify_oldpool;
}
dkim_signing_domain = US sig->domain;
dkim_signing_selector = US sig->selector;
- dkim_key_length = sig->sigdata.len * 8;
+ dkim_key_length = sig->sighash.len * 8;
return;
}
}
}
+/* Generate signatures for the given file, returning a string.
+If a prefix is given, prepend it to the file for the calculations.
+*/
+
uschar *
-dkim_exim_sign(int dkim_fd, uschar * dkim_private_key,
- const uschar * dkim_domain, uschar * dkim_selector,
- uschar * dkim_canon, uschar * dkim_sign_headers)
+dkim_exim_sign(int fd, off_t off, uschar * prefix,
+ struct ob_dkim * dkim, const uschar ** errstr)
{
+const uschar * dkim_domain;
int sep = 0;
uschar *seen_items = NULL;
int seen_items_size = 0;
int seen_items_offset = 0;
-uschar itembuf[256];
uschar *dkim_canon_expanded;
uschar *dkim_sign_headers_expanded;
uschar *dkim_private_key_expanded;
int pdkim_canon;
int pdkim_rc;
int sread;
-char buf[4096];
+uschar buf[4096];
int save_errno = 0;
int old_pool = store_pool;
store_pool = POOL_MAIN;
-if (!(dkim_domain = expand_cstring(dkim_domain)))
+if (!(dkim_domain = expand_cstring(dkim->dkim_domain)))
{
/* expansion error, do not send message. */
log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand "
"dkim_domain: %s", expand_string_message);
- rc = NULL;
- goto CLEANUP;
+ goto bad;
}
/* Set $dkim_domain expansion variable to each unique domain in list. */
-while ((dkim_signing_domain = string_nextinlist(&dkim_domain, &sep,
- itembuf, sizeof(itembuf))))
+while ((dkim_signing_domain = string_nextinlist(&dkim_domain, &sep, NULL, 0)))
{
- if (!dkim_signing_domain || dkim_signing_domain[0] == '\0')
+ if (dkim_signing_domain[0] == '\0')
continue;
/* Only sign once for each domain, no matter how often it
/* Set up $dkim_selector expansion variable. */
- if (!(dkim_signing_selector = expand_string(dkim_selector)))
+ if (!(dkim_signing_selector = expand_string(dkim->dkim_selector)))
{
log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand "
"dkim_selector: %s", expand_string_message);
- rc = NULL;
- goto CLEANUP;
+ goto bad;
}
/* Get canonicalization to use */
- dkim_canon_expanded = dkim_canon ? expand_string(dkim_canon) : US"relaxed";
+ dkim_canon_expanded = dkim->dkim_canon
+ ? expand_string(dkim->dkim_canon) : US"relaxed";
if (!dkim_canon_expanded)
{
/* expansion error, do not send message. */
log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand "
"dkim_canon: %s", expand_string_message);
- rc = NULL;
- goto CLEANUP;
+ goto bad;
}
if (Ustrcmp(dkim_canon_expanded, "relaxed") == 0)
}
dkim_sign_headers_expanded = NULL;
- if (dkim_sign_headers)
- if (!(dkim_sign_headers_expanded = expand_string(dkim_sign_headers)))
+ if (dkim->dkim_sign_headers)
+ if (!(dkim_sign_headers_expanded = expand_string(dkim->dkim_sign_headers)))
{
log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand "
"dkim_sign_headers: %s", expand_string_message);
- rc = NULL;
- goto CLEANUP;
+ goto bad;
}
/* else pass NULL, which means default header list */
/* Get private key to use. */
- if (!(dkim_private_key_expanded = expand_string(dkim_private_key)))
+ if (!(dkim_private_key_expanded = expand_string(dkim->dkim_private_key)))
{
log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand "
"dkim_private_key: %s", expand_string_message);
- rc = NULL;
- goto CLEANUP;
+ goto bad;
}
if ( Ustrlen(dkim_private_key_expanded) == 0
if (dkim_private_key_expanded[0] == '/')
{
- int privkey_fd = 0;
+ int privkey_fd, off = 0, len;
/* Looks like a filename, load the private key. */
memset(big_buffer, 0, big_buffer_size);
- privkey_fd = open(CS dkim_private_key_expanded, O_RDONLY);
- if (privkey_fd < 0)
+
+ if ((privkey_fd = open(CS dkim_private_key_expanded, O_RDONLY)) < 0)
{
log_write(0, LOG_MAIN | LOG_PANIC, "unable to open "
"private key file for reading: %s",
dkim_private_key_expanded);
- rc = NULL;
- goto CLEANUP;
+ goto bad;
}
- if (read(privkey_fd, big_buffer, big_buffer_size - 2) < 0)
+ do
{
- log_write(0, LOG_MAIN|LOG_PANIC, "unable to read private key file: %s",
- dkim_private_key_expanded);
- rc = NULL;
- goto CLEANUP;
+ if ((len = read(privkey_fd, big_buffer + off, big_buffer_size - 2 - off)) < 0)
+ {
+ (void) close(privkey_fd);
+ log_write(0, LOG_MAIN|LOG_PANIC, "unable to read private key file: %s",
+ dkim_private_key_expanded);
+ goto bad;
+ }
+ off += len;
}
+ while (len > 0);
(void) close(privkey_fd);
+ big_buffer[off] = '\0';
dkim_private_key_expanded = big_buffer;
}
- ctx = pdkim_init_sign( (char *) dkim_signing_domain,
- (char *) dkim_signing_selector,
- (char *) dkim_private_key_expanded,
- PDKIM_ALGO_RSA_SHA256);
+ if (!(ctx = pdkim_init_sign(CS dkim_signing_domain,
+ CS dkim_signing_selector,
+ CS dkim_private_key_expanded,
+ PDKIM_ALGO_RSA_SHA256,
+ dkim->dot_stuffed,
+ &dkim_exim_query_dns_txt,
+ errstr
+ )))
+ goto bad;
+ dkim_private_key_expanded[0] = '\0';
pdkim_set_optional(ctx,
- (char *) dkim_sign_headers_expanded,
+ CS dkim_sign_headers_expanded,
NULL,
pdkim_canon,
pdkim_canon, -1, 0, 0);
- lseek(dkim_fd, 0, SEEK_SET);
+ if (prefix)
+ pdkim_feed(ctx, prefix, Ustrlen(prefix));
- while ((sread = read(dkim_fd, &buf, 4096)) > 0)
- if (pdkim_feed(ctx, buf, sread) != PDKIM_OK)
- {
- rc = NULL;
- goto CLEANUP;
- }
+ if (lseek(fd, off, SEEK_SET) < 0)
+ sread = -1;
+ else
+ while ((sread = read(fd, &buf, sizeof(buf))) > 0)
+ if ((pdkim_rc = pdkim_feed(ctx, buf, sread)) != PDKIM_OK)
+ goto pk_bad;
/* Handle failed read above. */
if (sread == -1)
{
debug_printf("DKIM: Error reading -K file.\n");
save_errno = errno;
- rc = NULL;
- goto CLEANUP;
+ goto bad;
}
- if ((pdkim_rc = pdkim_feed_finish(ctx, &signature)) != PDKIM_OK)
- {
- log_write(0, LOG_MAIN|LOG_PANIC, "DKIM: signing failed (RC %d)", pdkim_rc);
- rc = NULL;
- goto CLEANUP;
- }
+ if ((pdkim_rc = pdkim_feed_finish(ctx, &signature, errstr)) != PDKIM_OK)
+ goto pk_bad;
sigbuf = string_append(sigbuf, &sigsize, &sigptr, 2,
US signature->signature_header, US"\r\n");
rc = US"";
CLEANUP:
-if (ctx)
- pdkim_free_ctx(ctx);
-store_pool = old_pool;
-errno = save_errno;
-return rc;
+ if (ctx)
+ pdkim_free_ctx(ctx);
+ store_pool = old_pool;
+ errno = save_errno;
+ return rc;
+
+pk_bad:
+ log_write(0, LOG_MAIN|LOG_PANIC,
+ "DKIM: signing failed: %.100s", pdkim_errstr(pdkim_rc));
+bad:
+ rc = NULL;
+ goto CLEANUP;
}
#endif
git://git.exim.org / exim.git / blobdiff