/*
* PDKIM - a RFC4871 (DKIM) implementation
*
- * Copyright (C) 2009 - 2016 Tom Kistner <tom@duncanthrax.net>
+ * Copyright (c) The Exim Maintainers 2021 - 2023
* Copyright (C) 2016 - 2020 Jeremy Harris <jgh@exim.org>
+ * Copyright (C) 2009 - 2016 Tom Kistner <tom@duncanthrax.net>
+ * SPDX-License-Identifier: GPL-2.0-or-later
*
* http://duncanthrax.net/pdkim/
*
};
-static blob lineending = {.data = US"\r\n", .len = 2};
+static const blob lineending = {.data = US"\r\n", .len = 2};
/* -------------------------------------------------------------------------- */
uschar *
static pdkim_stringlist *
pdkim_prepend_stringlist(pdkim_stringlist * base, const uschar * str)
{
-pdkim_stringlist * new_entry = store_get(sizeof(pdkim_stringlist), FALSE);
+pdkim_stringlist * new_entry = store_get(sizeof(pdkim_stringlist), GET_UNTAINTED);
memset(new_entry, 0, sizeof(pdkim_stringlist));
new_entry->value = string_copy(str);
{
BOOL past_field_name = FALSE;
BOOL seen_wsp = FALSE;
-uschar * relaxed = store_get(len+3, TRUE); /* tainted */
+uschar * relaxed = store_get(len+3, GET_TAINTED);
uschar * q = relaxed;
for (const uschar * p = header; p - header < len; p++)
int nchar = 0;
uschar * q;
const uschar * p = str;
-uschar * n = store_get(Ustrlen(str)+1, TRUE);
+uschar * n = store_get(Ustrlen(str)+1, GET_TAINTED);
*n = '\0';
q = n;
void
pdkim_decode_base64(const uschar * str, blob * b)
{
-int dlen = b64decode(str, &b->data);
+int dlen = b64decode(str, &b->data, str);
if (dlen < 0) b->data = NULL;
b->len = dlen;
}
BOOL in_b_val = FALSE;
int where = PDKIM_HDR_LIMBO;
-sig = store_get(sizeof(pdkim_signature), FALSE);
+sig = store_get(sizeof(pdkim_signature), GET_UNTAINTED);
memset(sig, 0, sizeof(pdkim_signature));
sig->bodylength = -1;
sig->keytype = -1;
sig->hashtype = -1;
-q = sig->rawsig_no_b_val = store_get(Ustrlen(raw_hdr)+1, TRUE); /* tainted */
+q = sig->rawsig_no_b_val = store_get(Ustrlen(raw_hdr)+1, GET_TAINTED);
for (uschar * p = raw_hdr; ; p++)
{
}
if (where == PDKIM_HDR_TAG)
- {
- if (c >= 'a' && c <= 'z')
- cur_tag = string_catn(cur_tag, p, 1);
-
if (c == '=')
{
if (Ustrcmp(string_from_gstring(cur_tag), "b") == 0)
where = PDKIM_HDR_VALUE;
goto NEXT_CHAR;
}
- }
+ else if (!isspace(c))
+ cur_tag = string_catn(cur_tag, p, 1);
if (where == PDKIM_HDR_VALUE)
{
switch (cur_tag->s[1])
{
case '\0': pdkim_decode_base64(cur_val->s, &sig->sighash); break;
- case 'h': if (cur_tag->ptr == 2)
- pdkim_decode_base64(cur_val->s, &sig->bodyhash);
+ case 'h': if (cur_tag->ptr != 2) goto bad_tag;
+ pdkim_decode_base64(cur_val->s, &sig->bodyhash);
break;
- default: break;
+ default: goto bad_tag;
}
break;
case 'v': /* version */
/* We only support version 1, and that is currently the
only version there is. */
sig->version =
- Ustrcmp(cur_val->s, PDKIM_SIGNATURE_VERSION) == 0 ? 1 : -1;
+ Ustrcmp(cur_val->s, PDKIM_SIGNATURE_VERSION) == 0 ? 1 : -1;
break;
case 'a': /* algorithm */
{
if (Ustrcmp(elem, pdkim_hashes[i].dkim_hashname) == 0)
{ sig->hashtype = i; break; }
}
+ break;
case 'c': /* canonicalization */
pdkim_cstring_to_canons(cur_val->s, 0,
case 'q': /* Query method (for pubkey)*/
for (int i = 0; pdkim_querymethods[i]; i++)
if (Ustrcmp(cur_val->s, pdkim_querymethods[i]) == 0)
- {
+ {
sig->querymethod = i; /* we never actually use this */
break;
}
break;
case 's': /* Selector */
- sig->selector = string_copyn(cur_val->s, cur_val->ptr); break;
+ sig->selector = string_copy_from_gstring(cur_val); break;
case 'd': /* SDID */
- sig->domain = string_copyn(cur_val->s, cur_val->ptr); break;
+ sig->domain = string_copy_from_gstring(cur_val); break;
case 'i': /* AUID */
sig->identity = pdkim_decode_qp(cur_val->s); break;
case 't': /* Timestamp */
case 'l': /* Body length count */
sig->bodylength = strtol(CS cur_val->s, NULL, 10); break;
case 'h': /* signed header fields */
- sig->headernames = string_copyn(cur_val->s, cur_val->ptr); break;
+ sig->headernames = string_copy_from_gstring(cur_val); break;
case 'z': /* Copied headfields */
sig->copiedheaders = pdkim_decode_qp(cur_val->s); break;
/*XXX draft-ietf-dcrup-dkim-crypto-05 would need 'p' tag support
for rsafp signatures. But later discussion is dropping those. */
default:
- DEBUG(D_acl) debug_printf(" Unknown tag encountered\n");
- break;
+ goto bad_tag;
}
}
+ else
+bad_tag: DEBUG(D_acl) debug_printf(" Unknown tag encountered: %Y\n", cur_tag);
+
cur_tag = cur_val = NULL;
in_b_val = FALSE;
where = PDKIM_HDR_LIMBO;
/* -------------------------------------------------------------------------- */
pdkim_pubkey *
-pdkim_parse_pubkey_record(const uschar *raw_record)
+pdkim_parse_pubkey_record(const uschar * raw_record)
{
-const uschar * ele;
-int sep = ';';
-pdkim_pubkey * pub;
+pdkim_pubkey * pub = store_get(sizeof(pdkim_pubkey), GET_TAINTED);
-pub = store_get(sizeof(pdkim_pubkey), TRUE); /* tainted */
memset(pub, 0, sizeof(pdkim_pubkey));
-while ((ele = string_nextinlist(&raw_record, &sep, NULL, 0)))
+for (const uschar * ele = raw_record, * tspec, * end, * val; *ele; ele = end)
{
- const uschar * val;
+ Uskip_whitespace(&ele);
+ end = US strchrnul(CS ele, ';');
+ tspec = string_copyn(ele, end - ele);
+ if (*end) end++; /* skip the ; */
- if ((val = Ustrchr(ele, '=')))
+ if ((val = Ustrchr(tspec, '=')))
{
- int taglen = val++ - ele;
+ int taglen = val++ - tspec;
+
+ DEBUG(D_acl) debug_printf(" %.*s=%s\n", taglen, tspec, val);
+ while (taglen > 1 && isspace(tspec[taglen-1]))
+ taglen--; /* Ignore whitespace before = */
+ Uskip_whitespace(&val); /* Ignore whitespace after = */
+ if (isspace(val[ Ustrlen(val)-1 ]))
+ { /* Ignore whitespace after value */
+ gstring * g = string_cat(NULL, val);
+ while (isspace(gstring_last_char(g)))
+ gstring_trim(g, 1);
+ val = string_from_gstring(g);
+ }
- DEBUG(D_acl) debug_printf(" %.*s=%s\n", taglen, ele, val);
- switch (ele[0])
+ if (taglen == 1) switch (tspec[0])
{
case 'v': pub->version = val; break;
case 'h': pub->hashes = val; break;
case 't': if (Ustrchr(val, 'y')) pub->testing = 1;
if (Ustrchr(val, 's')) pub->no_subdomaining = 1;
break;
- default: DEBUG(D_acl) debug_printf(" Unknown tag encountered\n"); break;
+ default: goto bad_tag;
}
+ else
+bad_tag:
+ DEBUG(D_acl) debug_printf(" Unknown tag encountered\n");
}
}
If we have to relax the data for this sig, return our copy of it. */
static blob *
-pdkim_update_ctx_bodyhash(pdkim_bodyhash * b, blob * orig_data, blob * relaxed_data)
+pdkim_update_ctx_bodyhash(pdkim_bodyhash * b, const blob * orig_data, blob * relaxed_data)
{
-blob * canon_data = orig_data;
+const blob * canon_data = orig_data;
+size_t left;
+
/* Defaults to simple canon (no further treatment necessary) */
if (b->canon_method == PDKIM_CANON_RELAXED)
}
/* Make sure we don't exceed the to-be-signed body length */
+left = canon_data->len;
if ( b->bodylength >= 0
- && b->signed_body_bytes + (unsigned long)canon_data->len > b->bodylength
+ && left > (unsigned long)b->bodylength - b->signed_body_bytes
)
- canon_data->len = b->bodylength - b->signed_body_bytes;
+ left = (unsigned long)b->bodylength - b->signed_body_bytes;
-if (canon_data->len > 0)
+if (left > 0)
{
- exim_sha_update(&b->body_hash_ctx, CUS canon_data->data, canon_data->len);
- b->signed_body_bytes += canon_data->len;
- DEBUG(D_acl) pdkim_quoteprint(canon_data->data, canon_data->len);
+ exim_sha_update(&b->body_hash_ctx, CUS canon_data->data, left);
+ b->signed_body_bytes += left;
+ DEBUG(D_acl) pdkim_quoteprint(canon_data->data, left);
}
return relaxed_data;
{
for (pdkim_bodyhash * b = ctx->bodyhash; b; b = b->next) /* Finish hashes */
{
- DEBUG(D_acl) debug_printf("DKIM: finish bodyhash %d/%d/%ld len %ld\n",
- b->hashtype, b->canon_method, b->bodylength, b->signed_body_bytes);
+ DEBUG(D_acl) debug_printf("DKIM: finish bodyhash %s/%s/%ld len %ld\n",
+ pdkim_hashes[b->hashtype].dkim_hashname, pdkim_canons[b->canon_method],
+ b->bodylength, b->signed_body_bytes);
exim_sha_finish(&b->body_hash_ctx, &b->bh);
}
DEBUG(D_acl)
{
- debug_printf("DKIM [%s] Body bytes (%s) hashed: %lu\n"
- "DKIM [%s] Body %s computed: ",
- sig->domain, pdkim_canons[b->canon_method], b->signed_body_bytes,
- sig->domain, pdkim_hashes[b->hashtype].dkim_hashname);
+ debug_printf("DKIM [%s]%s Body bytes (%s) hashed: %lu\n"
+ "DKIM [%s]%s Body %s computed: ",
+ sig->domain, sig->selector, pdkim_canons[b->canon_method], b->signed_body_bytes,
+ sig->domain, sig->selector, pdkim_hashes[b->hashtype].dkim_hashname);
pdkim_hexprint(CUS b->bh.data, b->bh.len);
}
/* VERIFICATION --------------------------------------------------------- */
/* Be careful that the header sig included a bodyash */
- if ( sig->bodyhash.data
+ if (sig->bodyhash.data && sig->bodyhash.len == b->bh.len
&& memcmp(b->bh.data, sig->bodyhash.data, b->bh.len) == 0)
{
DEBUG(D_acl) debug_printf("DKIM [%s] Body hash compared OK\n", sig->domain);
static int
pdkim_header_complete(pdkim_ctx * ctx)
{
-if ( (ctx->cur_header->ptr > 1) &&
- (ctx->cur_header->s[ctx->cur_header->ptr-1] == '\r') )
- --ctx->cur_header->ptr;
+if (ctx->cur_header->ptr > 1)
+ gstring_trim_trailing(ctx->cur_header, '\r');
(void) string_from_gstring(ctx->cur_header);
#ifdef EXPERIMENTAL_ARC
last_sig->next = sig;
}
- if (--dkim_collect_input == 0)
+ if (dkim_collect_input && --dkim_collect_input == 0)
{
ctx->headers = pdkim_prepend_stringlist(ctx->headers, ctx->cur_header->s);
ctx->cur_header->s[ctx->cur_header->ptr = 0] = '\0';
if (sig->created > 0)
{
- uschar minibuf[20];
+ uschar minibuf[21];
snprintf(CS minibuf, sizeof(minibuf), "%lu", sig->created);
hdr = pdkim_headcat(&col, hdr, US";", US"t=", minibuf);
if (sig->expires > 0)
{
- uschar minibuf[20];
+ uschar minibuf[21];
snprintf(CS minibuf, sizeof(minibuf), "%lu", sig->expires);
hdr = pdkim_headcat(&col, hdr, US";", US"x=", minibuf);
if (sig->bodylength >= 0)
{
- uschar minibuf[20];
+ uschar minibuf[21];
snprintf(CS minibuf, sizeof(minibuf), "%lu", sig->bodylength);
hdr = pdkim_headcat(&col, hdr, US";", US"l=", minibuf);
rh = pdkim_relax_header(rh, TRUE); /* cook header for relaxed canon */
/* Feed header to the hash algorithm */
- exim_sha_update(&hhash_ctx, CUS rh, Ustrlen(rh));
+ exim_sha_update_string(&hhash_ctx, CUS rh);
/* Remember headers block for signing (when the library cannot do incremental) */
/*XXX we could avoid doing this for all but the GnuTLS/RSA case */
: string_copy(CUS hdrs->value);
/* Feed header to the hash algorithm */
- exim_sha_update(&hhash_ctx, CUS rh, Ustrlen(rh));
+ exim_sha_update_string(&hhash_ctx, CUS rh);
DEBUG(D_acl) pdkim_quoteprint(rh, Ustrlen(rh));
hdrs->tag = 1;
}
/* Finalize header hash */
- exim_sha_update(&hhash_ctx, CUS sig_hdr, Ustrlen(sig_hdr));
+ exim_sha_update_string(&hhash_ctx, CUS sig_hdr);
exim_sha_finish(&hhash_ctx, &hhash);
DEBUG(D_acl)
if (*dkim_verify_min_keysizes)
{
unsigned minbits;
- uschar * ss = expand_getkeyed(US pdkim_keytypes[sig->keytype],
+ const uschar * ss = expand_getkeyed(US pdkim_keytypes[sig->keytype],
dkim_verify_min_keysizes);
- if (ss && (minbits = atoi(CS ss)) > sig->keybits)
+ if (ss && (minbits = atoi(CCS ss)) > sig->keybits)
{
DEBUG(D_acl) debug_printf("Key too short: Actual: %s %u Minima '%s'\n",
pdkim_keytypes[sig->keytype], sig->keybits, dkim_verify_min_keysizes);
{
pdkim_ctx * ctx;
-ctx = store_get(sizeof(pdkim_ctx), FALSE);
+ctx = store_get(sizeof(pdkim_ctx), GET_UNTAINTED);
memset(ctx, 0, sizeof(pdkim_ctx));
if (dot_stuffing) ctx->flags = PDKIM_DOT_TERM;
/* The line-buffer is for message data, hence tainted */
-ctx->linebuf = store_get(PDKIM_MAX_BODY_LINE_LEN, TRUE);
+ctx->linebuf = store_get(PDKIM_MAX_BODY_LINE_LEN, GET_TAINTED);
ctx->dns_txt_callback = dns_txt_callback;
+ctx->cur_header = string_get_tainted(36, GET_TAINTED);
return ctx;
}
/* Allocate & init one signature struct */
-sig = store_get(sizeof(pdkim_signature), FALSE);
+sig = store_get(sizeof(pdkim_signature), GET_UNTAINTED);
memset(sig, 0, sizeof(pdkim_signature));
sig->bodylength = -1;
&& canon_method == b->canon_method
&& bodylength == b->bodylength)
{
- DEBUG(D_receive) debug_printf("DKIM: using existing bodyhash %d/%d/%ld\n",
- hashtype, canon_method, bodylength);
+ DEBUG(D_receive) debug_printf("DKIM: using existing bodyhash %s/%s/%ld\n",
+ pdkim_hashes[hashtype].dkim_hashname, pdkim_canons[canon_method], bodylength);
return b;
}
-DEBUG(D_receive) debug_printf("DKIM: new bodyhash %d/%d/%ld\n",
- hashtype, canon_method, bodylength);
-b = store_get(sizeof(pdkim_bodyhash), FALSE);
+DEBUG(D_receive) debug_printf("DKIM: new bodyhash %s/%s/%ld\n",
+ pdkim_hashes[hashtype].dkim_hashname, pdkim_canons[canon_method], bodylength);
+b = store_get(sizeof(pdkim_bodyhash), GET_UNTAINTED);
b->next = ctx->bodyhash;
b->hashtype = hashtype;
b->canon_method = canon_method;
memset(ctx, 0, sizeof(pdkim_ctx));
ctx->flags = dot_stuffed ? PDKIM_MODE_SIGN | PDKIM_DOT_TERM : PDKIM_MODE_SIGN;
/* The line buffer is for message data, hence tainted */
-ctx->linebuf = store_get(PDKIM_MAX_BODY_LINE_LEN, TRUE);
+ctx->linebuf = store_get(PDKIM_MAX_BODY_LINE_LEN, GET_TAINTED);
DEBUG(D_acl) ctx->dns_txt_callback = dns_txt_callback;
}
git://git.exim.org / exim.git / blobdiff