* PDKIM - a RFC4871 (DKIM) implementation
*
* Copyright (C) 2009 - 2016 Tom Kistner <tom@duncanthrax.net>
- * Copyright (C) 2016 Jeremy Harris <jgh@exim.org>
+ * Copyright (C) 2016 - 2017 Jeremy Harris <jgh@exim.org>
*
* http://duncanthrax.net/pdkim/
*
#endif
#include "pdkim.h"
-#include "rsa.h"
+#include "signing.h"
#define PDKIM_SIGNATURE_VERSION "1"
-#define PDKIM_PUB_RECORD_VERSION "DKIM1"
+#define PDKIM_PUB_RECORD_VERSION US "DKIM1"
#define PDKIM_MAX_HEADER_LEN 65536
#define PDKIM_MAX_HEADERS 512
/* -------------------------------------------------------------------------- */
struct pdkim_stringlist {
- char *value;
- int tag;
- void *next;
-};
-
-#define PDKIM_STR_ALLOC_FRAG 256
-struct pdkim_str {
- char *str;
- unsigned int len;
- unsigned int allocated;
+ uschar * value;
+ int tag;
+ void * next;
};
/* -------------------------------------------------------------------------- */
/* A bunch of list constants */
-const char *pdkim_querymethods[] = {
- "dns/txt",
+const uschar * pdkim_querymethods[] = {
+ US"dns/txt",
NULL
};
-const char *pdkim_algos[] = {
- "rsa-sha256",
- "rsa-sha1",
+const uschar * pdkim_algos[] = {
+ US"rsa-sha256",
+ US"rsa-sha1",
NULL
};
-const char *pdkim_canons[] = {
- "simple",
- "relaxed",
+const uschar * pdkim_canons[] = {
+ US"simple",
+ US"relaxed",
NULL
};
-const char *pdkim_hashes[] = {
- "sha256",
- "sha1",
+/*XXX currently unused */
+const uschar * pdkim_hashes[] = {
+ US"sha256",
+ US"sha1",
NULL
};
-const char *pdkim_keytypes[] = {
- "rsa",
+/*XXX currently unused */
+const uschar * pdkim_keytypes[] = {
+ US"rsa",
NULL
};
typedef struct pdkim_combined_canon_entry {
- const char *str;
+ const uschar * str;
int canon_headers;
int canon_body;
} pdkim_combined_canon_entry;
pdkim_combined_canon_entry pdkim_combined_canons[] = {
- { "simple/simple", PDKIM_CANON_SIMPLE, PDKIM_CANON_SIMPLE },
- { "simple/relaxed", PDKIM_CANON_SIMPLE, PDKIM_CANON_RELAXED },
- { "relaxed/simple", PDKIM_CANON_RELAXED, PDKIM_CANON_SIMPLE },
- { "relaxed/relaxed", PDKIM_CANON_RELAXED, PDKIM_CANON_RELAXED },
- { "simple", PDKIM_CANON_SIMPLE, PDKIM_CANON_SIMPLE },
- { "relaxed", PDKIM_CANON_RELAXED, PDKIM_CANON_SIMPLE },
- { NULL, 0, 0 }
+ { US"simple/simple", PDKIM_CANON_SIMPLE, PDKIM_CANON_SIMPLE },
+ { US"simple/relaxed", PDKIM_CANON_SIMPLE, PDKIM_CANON_RELAXED },
+ { US"relaxed/simple", PDKIM_CANON_RELAXED, PDKIM_CANON_SIMPLE },
+ { US"relaxed/relaxed", PDKIM_CANON_RELAXED, PDKIM_CANON_RELAXED },
+ { US"simple", PDKIM_CANON_SIMPLE, PDKIM_CANON_SIMPLE },
+ { US"relaxed", PDKIM_CANON_RELAXED, PDKIM_CANON_SIMPLE },
+ { NULL, 0, 0 }
};
const char *
pdkim_verify_status_str(int status)
{
- switch(status) {
- case PDKIM_VERIFY_NONE: return "PDKIM_VERIFY_NONE";
- case PDKIM_VERIFY_INVALID: return "PDKIM_VERIFY_INVALID";
- case PDKIM_VERIFY_FAIL: return "PDKIM_VERIFY_FAIL";
- case PDKIM_VERIFY_PASS: return "PDKIM_VERIFY_PASS";
- default: return "PDKIM_VERIFY_UNKNOWN";
+switch(status)
+ {
+ case PDKIM_VERIFY_NONE: return "PDKIM_VERIFY_NONE";
+ case PDKIM_VERIFY_INVALID: return "PDKIM_VERIFY_INVALID";
+ case PDKIM_VERIFY_FAIL: return "PDKIM_VERIFY_FAIL";
+ case PDKIM_VERIFY_PASS: return "PDKIM_VERIFY_PASS";
+ default: return "PDKIM_VERIFY_UNKNOWN";
}
}
const char *
pdkim_verify_ext_status_str(int ext_status)
{
- switch(ext_status) {
- case PDKIM_VERIFY_FAIL_BODY: return "PDKIM_VERIFY_FAIL_BODY";
- case PDKIM_VERIFY_FAIL_MESSAGE: return "PDKIM_VERIFY_FAIL_MESSAGE";
- case PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE: return "PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE";
- case PDKIM_VERIFY_INVALID_BUFFER_SIZE: return "PDKIM_VERIFY_INVALID_BUFFER_SIZE";
- case PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD: return "PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD";
- case PDKIM_VERIFY_INVALID_PUBKEY_IMPORT: return "PDKIM_VERIFY_INVALID_PUBKEY_IMPORT";
- default: return "PDKIM_VERIFY_UNKNOWN";
+switch(ext_status)
+ {
+ case PDKIM_VERIFY_FAIL_BODY: return "PDKIM_VERIFY_FAIL_BODY";
+ case PDKIM_VERIFY_FAIL_MESSAGE: return "PDKIM_VERIFY_FAIL_MESSAGE";
+ case PDKIM_VERIFY_FAIL_SIG_ALGO_MISMATCH: return "PDKIM_VERIFY_FAIL_SIG_ALGO_MISMATCH";
+ case PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE: return "PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE";
+ case PDKIM_VERIFY_INVALID_BUFFER_SIZE: return "PDKIM_VERIFY_INVALID_BUFFER_SIZE";
+ case PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD: return "PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD";
+ case PDKIM_VERIFY_INVALID_PUBKEY_IMPORT: return "PDKIM_VERIFY_INVALID_PUBKEY_IMPORT";
+ case PDKIM_VERIFY_INVALID_SIGNATURE_ERROR: return "PDKIM_VERIFY_INVALID_SIGNATURE_ERROR";
+ case PDKIM_VERIFY_INVALID_DKIM_VERSION: return "PDKIM_VERIFY_INVALID_DKIM_VERSION";
+ default: return "PDKIM_VERIFY_UNKNOWN";
+ }
+}
+
+const uschar *
+pdkim_errstr(int status)
+{
+switch(status)
+ {
+ case PDKIM_OK: return US"OK";
+ case PDKIM_FAIL: return US"FAIL";
+ case PDKIM_ERR_RSA_PRIVKEY: return US"RSA_PRIVKEY";
+ case PDKIM_ERR_RSA_SIGNING: return US"RSA SIGNING";
+ case PDKIM_ERR_LONG_LINE: return US"RSA_LONG_LINE";
+ case PDKIM_ERR_BUFFER_TOO_SMALL: return US"BUFFER_TOO_SMALL";
+ case PDKIM_SIGN_PRIVKEY_WRAP: return US"PRIVKEY_WRAP";
+ case PDKIM_SIGN_PRIVKEY_B64D: return US"PRIVKEY_B64D";
+ default: return US"(unknown)";
}
}
/* -------------------------------------------------------------------------- */
/* Print debugging functions */
static void
-pdkim_quoteprint(const char *data, int len)
+pdkim_quoteprint(const uschar *data, int len)
{
int i;
-const unsigned char *p = (const unsigned char *)data;
-
for (i = 0; i < len; i++)
{
- const int c = p[i];
+ const int c = data[i];
switch (c)
{
case ' ' : debug_printf("{SP}"); break;
}
static void
-pdkim_hexprint(const char *data, int len)
+pdkim_hexprint(const uschar *data, int len)
{
int i;
-const unsigned char *p = (const unsigned char *)data;
-
-for (i = 0 ; i < len; i++)
- debug_printf("%02x", p[i]);
+if (data) for (i = 0 ; i < len; i++) debug_printf("%02x", data[i]);
+else debug_printf("<NULL>");
debug_printf("\n");
}
-/* String package: should be replaced by Exim standard ones */
-
static pdkim_stringlist *
-pdkim_prepend_stringlist(pdkim_stringlist *base, char *str)
+pdkim_prepend_stringlist(pdkim_stringlist * base, const uschar * str)
{
-pdkim_stringlist *new_entry = malloc(sizeof(pdkim_stringlist));
+pdkim_stringlist * new_entry = store_get(sizeof(pdkim_stringlist));
-if (!new_entry) return NULL;
memset(new_entry, 0, sizeof(pdkim_stringlist));
-if (!(new_entry->value = strdup(str))) return NULL;
-if (base)
- {
- pdkim_stringlist *last = base;
- while (last->next != NULL) { last = last->next; }
- last->next = new_entry;
- return base;
- }
-else
- return new_entry;
+new_entry->value = string_copy(str);
+if (base) new_entry->next = base;
+return new_entry;
}
-/* -------------------------------------------------------------------------- */
-/* A small "growing string" implementation to escape malloc/realloc hell */
-
-static pdkim_str *
-pdkim_strnew (const char *cstr)
-{
-unsigned int len = cstr ? strlen(cstr) : 0;
-pdkim_str *p = malloc(sizeof(pdkim_str));
-
-if (!p) return NULL;
-memset(p, 0, sizeof(pdkim_str));
-if (!(p->str = malloc(len+1)))
- {
- free(p);
- return NULL;
- }
-p->allocated = len+1;
-p->len = len;
-if (cstr)
- strcpy(p->str, cstr);
-else
- p->str[p->len] = '\0';
-return p;
-}
-
-static char *
-pdkim_strncat(pdkim_str *str, const char *data, int len)
-{
-if ((str->allocated - str->len) < (len+1))
- {
- /* Extend the buffer */
- int num_frags = ((len+1)/PDKIM_STR_ALLOC_FRAG)+1;
- char *n = realloc(str->str,
- (str->allocated+(num_frags*PDKIM_STR_ALLOC_FRAG)));
- if (n == NULL) return NULL;
- str->str = n;
- str->allocated += (num_frags*PDKIM_STR_ALLOC_FRAG);
- }
-strncpy(&(str->str[str->len]), data, len);
-str->len += len;
-str->str[str->len] = '\0';
-return str->str;
-}
-static char *
-pdkim_strcat(pdkim_str *str, const char *cstr)
-{
-return pdkim_strncat(str, cstr, strlen(cstr));
-}
+/* Trim whitespace fore & aft */
-static char *
-pdkim_strtrim(pdkim_str *str)
+static void
+pdkim_strtrim(uschar * str)
{
-char *p = str->str;
-char *q = str->str;
-while ( (*p != '\0') && ((*p == '\t') || (*p == ' ')) ) p++;
-while (*p != '\0') {*q = *p; q++; p++;}
+uschar * p = str;
+uschar * q = str;
+while (*p == '\t' || *p == ' ') p++; /* skip whitespace */
+while (*p) {*q = *p; q++; p++;} /* dump the leading whitespace */
*q = '\0';
-while ( (q != str->str) && ( (*q == '\0') || (*q == '\t') || (*q == ' ') ) )
- {
+while (q != str && ( (*q == '\0') || (*q == '\t') || (*q == ' ') ) )
+ { /* dump trailing whitespace */
*q = '\0';
q--;
}
-str->len = strlen(str->str);
-return str->str;
-}
-
-static char *
-pdkim_strclear(pdkim_str *str)
-{
-str->str[0] = '\0';
-str->len = 0;
-return str->str;
-}
-
-static void
-pdkim_strfree(pdkim_str *str)
-{
-if (!str) return;
-if (str->str) free(str->str);
-free(str);
-}
-
-
-
-/* -------------------------------------------------------------------------- */
-
-static void
-pdkim_free_pubkey(pdkim_pubkey *pub)
-{
-if (pub)
- {
- if (pub->version ) free(pub->version);
- if (pub->granularity) free(pub->granularity);
- if (pub->hashes ) free(pub->hashes);
- if (pub->keytype ) free(pub->keytype);
- if (pub->srvtype ) free(pub->srvtype);
- if (pub->notes ) free(pub->notes);
- free(pub);
- }
}
-/* -------------------------------------------------------------------------- */
-
-static void
-pdkim_free_sig(pdkim_signature *sig)
-{
-if (sig)
- {
- pdkim_signature *next = (pdkim_signature *)sig->next;
-
- pdkim_stringlist *e = sig->headers;
- while(e)
- {
- pdkim_stringlist *c = e;
- if (e->value) free(e->value);
- e = e->next;
- free(c);
- }
-
- if (sig->selector ) free(sig->selector);
- if (sig->domain ) free(sig->domain);
- if (sig->identity ) free(sig->identity);
- if (sig->copiedheaders ) free(sig->copiedheaders);
- if (sig->rsa_privkey ) free(sig->rsa_privkey);
- if (sig->sign_headers ) free(sig->sign_headers);
- if (sig->signature_header) free(sig->signature_header);
-
- if (sig->pubkey) pdkim_free_pubkey(sig->pubkey);
-
- free(sig);
- if (next) pdkim_free_sig(next);
- }
-}
-
/* -------------------------------------------------------------------------- */
DLLEXPORT void
pdkim_free_ctx(pdkim_ctx *ctx)
{
-if (ctx)
- {
- pdkim_stringlist *e = ctx->headers;
- while(e)
- {
- pdkim_stringlist *c = e;
- if (e->value) free(e->value);
- e = e->next;
- free(c);
- }
- pdkim_free_sig(ctx->sig);
- pdkim_strfree(ctx->cur_header);
- free(ctx);
- }
}
/* -------------------------------------------------------------------------- */
/* Matches the name of the passed raw "header" against
- the passed colon-separated "list", starting at entry
- "start". Returns the position of the header name in
- the list. */
+ the passed colon-separated "tick", and invalidates
+ the entry in tick. Returns OK or fail-code */
+/*XXX might be safer done using a pdkim_stringlist for "tick" */
static int
-header_name_match(const char *header,
- char *tick,
- int do_tick)
+header_name_match(const uschar * header, uschar * tick)
{
-char *hname;
-char *lcopy;
-char *p;
-char *q;
-int rc = PDKIM_FAIL;
+uschar * hname;
+uschar * lcopy;
+uschar * p;
+uschar * q;
+uschar * hcolon = Ustrchr(header, ':'); /* Get header name */
-/* Get header name */
-char *hcolon = strchr(header, ':');
+if (!hcolon)
+ return PDKIM_FAIL; /* This isn't a header */
-if (!hcolon) return rc; /* This isn't a header */
-
-if (!(hname = malloc((hcolon-header)+1)))
- return PDKIM_ERR_OOM;
-memset(hname, 0, (hcolon-header)+1);
-strncpy(hname, header, (hcolon-header));
+/* if we had strncmpic() we wouldn't need this copy */
+hname = string_copyn(header, hcolon-header);
/* Copy tick-off list locally, so we can punch zeroes into it */
-if (!(lcopy = strdup(tick)))
- {
- free(hname);
- return PDKIM_ERR_OOM;
- }
-p = lcopy;
-q = strchr(p, ':');
-while (q)
+p = lcopy = string_copy(tick);
+
+for (q = Ustrchr(p, ':'); q; q = Ustrchr(p, ':'))
{
*q = '\0';
-
- if (strcasecmp(p, hname) == 0)
- {
- rc = PDKIM_OK;
- /* Invalidate header name instance in tick-off list */
- if (do_tick) tick[p-lcopy] = '_';
- goto BAIL;
- }
+ if (strcmpic(p, hname) == 0)
+ goto found;
p = q+1;
- q = strchr(p, ':');
}
-if (strcasecmp(p, hname) == 0)
- {
- rc = PDKIM_OK;
- /* Invalidate header name instance in tick-off list */
- if (do_tick) tick[p-lcopy] = '_';
- }
+if (strcmpic(p, hname) == 0)
+ goto found;
-BAIL:
-free(hname);
-free(lcopy);
-return rc;
+return PDKIM_FAIL;
+
+found:
+ /* Invalidate header name instance in tick-off list */
+ tick[p-lcopy] = '_';
+ return PDKIM_OK;
}
/* -------------------------------------------------------------------------- */
-/* Performs "relaxed" canonicalization of a header. The returned pointer needs
- to be free()d. */
+/* Performs "relaxed" canonicalization of a header. */
-static char *
-pdkim_relax_header (char *header, int crlf)
+static uschar *
+pdkim_relax_header(const uschar * header, BOOL append_crlf)
{
BOOL past_field_name = FALSE;
BOOL seen_wsp = FALSE;
-char *p;
-char *q;
-char *relaxed = malloc(strlen(header)+3);
+const uschar * p;
+uschar * relaxed = store_get(Ustrlen(header)+3);
+uschar * q = relaxed;
-if (!relaxed) return NULL;
-
-q = relaxed;
-for (p = header; *p != '\0'; p++)
+for (p = header; *p; p++)
{
- int c = *p;
- /* Ignore CR & LF */
- if (c == '\r' || c == '\n')
+ uschar c = *p;
+
+ if (c == '\r' || c == '\n') /* Ignore CR & LF */
continue;
if (c == '\t' || c == ' ')
{
else
if (!past_field_name && c == ':')
{
- if (seen_wsp) q--; /* This removes WSP before the colon */
- seen_wsp = TRUE; /* This removes WSP after the colon */
+ if (seen_wsp) q--; /* This removes WSP immediately before the colon */
+ seen_wsp = TRUE; /* This removes WSP immediately after the colon */
past_field_name = TRUE;
}
else
}
if (q > relaxed && q[-1] == ' ') q--; /* Squash eventual trailing SP */
-*q = '\0';
-if (crlf) strcat(relaxed, "\r\n");
+if (append_crlf) { *q++ = '\r'; *q++ = '\n'; }
+*q = '\0';
return relaxed;
}
/* -------------------------------------------------------------------------- */
#define PDKIM_QP_ERROR_DECODE -1
-static char *
-pdkim_decode_qp_char(char *qp_p, int *c)
+static const uschar *
+pdkim_decode_qp_char(const uschar *qp_p, int *c)
{
-char *initial_pos = qp_p;
+const uschar *initial_pos = qp_p;
/* Advance one char */
qp_p++;
/* -------------------------------------------------------------------------- */
-static char *
-pdkim_decode_qp(char *str)
+static uschar *
+pdkim_decode_qp(const uschar * str)
{
int nchar = 0;
-char *q;
-char *p = str;
-char *n = malloc(strlen(p)+1);
-
-if (!n) return NULL;
+uschar * q;
+const uschar * p = str;
+uschar * n = store_get(Ustrlen(str)+1);
*n = '\0';
q = n;
-while (*p != '\0')
+while (*p)
{
if (*p == '=')
{
/* -------------------------------------------------------------------------- */
static void
-pdkim_decode_base64(uschar *str, blob * b)
+pdkim_decode_base64(const uschar * str, blob * b)
{
int dlen;
-char *res;
dlen = b64decode(str, &b->data);
if (dlen < 0) b->data = NULL;
b->len = dlen;
}
-/* -------------------------------------------------------------------------- */
-
-static char *
+static uschar *
pdkim_encode_base64(blob * b)
{
-char * ret;
-int old_pool = store_pool;
-
-store_pool = POOL_PERM;
-ret = CS b64encode(b->data, b->len);
-store_pool = old_pool;
-return ret;
+return b64encode(b->data, b->len);
}
#define PDKIM_HDR_VALUE 2
static pdkim_signature *
-pdkim_parse_sig_header(pdkim_ctx *ctx, char *raw_hdr)
+pdkim_parse_sig_header(pdkim_ctx *ctx, uschar * raw_hdr)
{
-pdkim_signature *sig ;
-char *p, *q;
-pdkim_str *cur_tag = NULL;
-pdkim_str *cur_val = NULL;
+pdkim_signature * sig;
+uschar *p, *q;
+uschar * cur_tag = NULL; int ts = 0, tl = 0;
+uschar * cur_val = NULL; int vs = 0, vl = 0;
BOOL past_hname = FALSE;
BOOL in_b_val = FALSE;
int where = PDKIM_HDR_LIMBO;
int i;
-int old_pool = store_pool;
-/* There is a store-reset between header & body reception
-so cannot use the main pool. Any allocs done by Exim
-memory-handling must use the perm pool. */
-
-store_pool = POOL_PERM;
-
-if (!(sig = malloc(sizeof(pdkim_signature)))) return NULL;
+sig = store_get(sizeof(pdkim_signature));
memset(sig, 0, sizeof(pdkim_signature));
sig->bodylength = -1;
-if (!(sig->rawsig_no_b_val = malloc(strlen(raw_hdr)+1)))
- {
- free(sig);
- return NULL;
- }
+/* Set so invalid/missing data error display is accurate */
+sig->algo = -1;
+sig->version = 0;
-q = sig->rawsig_no_b_val;
+q = sig->rawsig_no_b_val = store_get(Ustrlen(raw_hdr)+1);
for (p = raw_hdr; ; p++)
{
if (where == PDKIM_HDR_TAG)
{
- if (!cur_tag)
- cur_tag = pdkim_strnew(NULL);
-
if (c >= 'a' && c <= 'z')
- pdkim_strncat(cur_tag, p, 1);
+ cur_tag = string_catn(cur_tag, &ts, &tl, p, 1);
if (c == '=')
{
- if (strcmp(cur_tag->str, "b") == 0)
+ cur_tag[tl] = '\0';
+ if (Ustrcmp(cur_tag, "b") == 0)
{
- *q = '='; q++;
+ *q++ = '=';
in_b_val = TRUE;
}
where = PDKIM_HDR_VALUE;
if (where == PDKIM_HDR_VALUE)
{
- if (!cur_val)
- cur_val = pdkim_strnew(NULL);
-
if (c == '\r' || c == '\n' || c == ' ' || c == '\t')
goto NEXT_CHAR;
if (c == ';' || c == '\0')
{
- if (cur_tag->len > 0)
+ if (tl && vl)
{
+ cur_val[vl] = '\0';
pdkim_strtrim(cur_val);
- DEBUG(D_acl) debug_printf(" %s=%s\n", cur_tag->str, cur_val->str);
+ DEBUG(D_acl) debug_printf(" %s=%s\n", cur_tag, cur_val);
- switch (cur_tag->str[0])
+ switch (*cur_tag)
{
case 'b':
- if (cur_tag->str[1] == 'h')
- pdkim_decode_base64(US cur_val->str, &sig->bodyhash);
- else
- pdkim_decode_base64(US cur_val->str, &sig->sigdata);
+ pdkim_decode_base64(cur_val,
+ cur_tag[1] == 'h' ? &sig->bodyhash : &sig->sighash);
break;
case 'v':
/* We only support version 1, and that is currently the
only version there is. */
- if (strcmp(cur_val->str, PDKIM_SIGNATURE_VERSION) == 0)
- sig->version = 1;
+ sig->version =
+ Ustrcmp(cur_val, PDKIM_SIGNATURE_VERSION) == 0 ? 1 : -1;
break;
case 'a':
+/*XXX this searches a list of combined (algo + hash-method)s */
for (i = 0; pdkim_algos[i]; i++)
- if (strcmp(cur_val->str, pdkim_algos[i]) == 0)
+ if (Ustrcmp(cur_val, pdkim_algos[i]) == 0)
{
sig->algo = i;
break;
break;
case 'c':
for (i = 0; pdkim_combined_canons[i].str; i++)
- if (strcmp(cur_val->str, pdkim_combined_canons[i].str) == 0)
+ if (Ustrcmp(cur_val, pdkim_combined_canons[i].str) == 0)
{
sig->canon_headers = pdkim_combined_canons[i].canon_headers;
sig->canon_body = pdkim_combined_canons[i].canon_body;
break;
case 'q':
for (i = 0; pdkim_querymethods[i]; i++)
- if (strcmp(cur_val->str, pdkim_querymethods[i]) == 0)
+ if (Ustrcmp(cur_val, pdkim_querymethods[i]) == 0)
{
sig->querymethod = i;
break;
}
break;
case 's':
- sig->selector = strdup(cur_val->str); break;
+ sig->selector = string_copy(cur_val); break;
case 'd':
- sig->domain = strdup(cur_val->str); break;
+ sig->domain = string_copy(cur_val); break;
case 'i':
- sig->identity = pdkim_decode_qp(cur_val->str); break;
+ sig->identity = pdkim_decode_qp(cur_val); break;
case 't':
- sig->created = strtoul(cur_val->str, NULL, 10); break;
+ sig->created = strtoul(CS cur_val, NULL, 10); break;
case 'x':
- sig->expires = strtoul(cur_val->str, NULL, 10); break;
+ sig->expires = strtoul(CS cur_val, NULL, 10); break;
case 'l':
- sig->bodylength = strtol(cur_val->str, NULL, 10); break;
+ sig->bodylength = strtol(CS cur_val, NULL, 10); break;
case 'h':
- sig->headernames = string_copy(cur_val->str); break;
+ sig->headernames = string_copy(cur_val); break;
case 'z':
- sig->copiedheaders = pdkim_decode_qp(cur_val->str); break;
+ sig->copiedheaders = pdkim_decode_qp(cur_val); break;
default:
DEBUG(D_acl) debug_printf(" Unknown tag encountered\n");
break;
}
}
- pdkim_strclear(cur_tag);
- pdkim_strclear(cur_val);
+ tl = 0;
+ vl = 0;
in_b_val = FALSE;
where = PDKIM_HDR_LIMBO;
}
else
- pdkim_strncat(cur_val, p, 1);
+ cur_val = string_catn(cur_val, &vs, &vl, p, 1);
}
NEXT_CHAR:
*q++ = c;
}
-store_pool = old_pool;
-
-/* Make sure the most important bits are there. */
-if (!(sig->domain && (*(sig->domain) != '\0') &&
- sig->selector && (*(sig->selector) != '\0') &&
- sig->headernames && (*(sig->headernames) != '\0') &&
- sig->version))
- {
- pdkim_free_sig(sig);
- return NULL;
- }
-
*q = '\0';
/* Chomp raw header. The final newline must not be added to the signature. */
-q--;
-while (q > sig->rawsig_no_b_val && (*q == '\r' || *q == '\n'))
- *q = '\0'; q--; /*XXX questionable code layout; possible bug */
+while (--q > sig->rawsig_no_b_val && (*q == '\r' || *q == '\n'))
+ *q = '\0';
DEBUG(D_acl)
{
debug_printf(
"PDKIM >> Raw signature w/o b= tag value >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
- pdkim_quoteprint(sig->rawsig_no_b_val, strlen(sig->rawsig_no_b_val));
+ pdkim_quoteprint(US sig->rawsig_no_b_val, Ustrlen(sig->rawsig_no_b_val));
debug_printf(
- "PDKIM >> Sig size: %4d bits\n", sig->sigdata.len*8);
+ "PDKIM >> Sig size: %4u bits\n", (unsigned) sig->sighash.len*8);
debug_printf(
"PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
}
-exim_sha_init(&sig->body_hash, sig->algo == PDKIM_ALGO_RSA_SHA1);
+/*XXX hash method: extend for sha512 */
+if (!exim_sha_init(&sig->body_hash_ctx,
+ sig->algo == PDKIM_ALGO_RSA_SHA1 ? HASH_SHA1 : HASH_SHA256))
+ {
+ DEBUG(D_acl) debug_printf("PDKIM: hash init internal error\n");
+ return NULL;
+ }
return sig;
}
/* -------------------------------------------------------------------------- */
static pdkim_pubkey *
-pdkim_parse_pubkey_record(pdkim_ctx *ctx, char *raw_record)
+pdkim_parse_pubkey_record(pdkim_ctx *ctx, const uschar *raw_record)
{
-pdkim_pubkey *pub;
-char *p;
-pdkim_str *cur_tag = NULL;
-pdkim_str *cur_val = NULL;
-int where = PDKIM_HDR_LIMBO;
+const uschar * ele;
+int sep = ';';
+pdkim_pubkey * pub;
-if (!(pub = malloc(sizeof(pdkim_pubkey)))) return NULL;
+pub = store_get(sizeof(pdkim_pubkey));
memset(pub, 0, sizeof(pdkim_pubkey));
-for (p = raw_record; ; p++)
+while ((ele = string_nextinlist(&raw_record, &sep, NULL, 0)))
{
- char c = *p;
-
- /* Ignore FWS */
- if (c == '\r' || c == '\n')
- goto NEXT_CHAR;
-
- if (where == PDKIM_HDR_LIMBO)
- {
- /* In limbo, just wait for a tag-char to appear */
- if (!(c >= 'a' && c <= 'z'))
- goto NEXT_CHAR;
-
- where = PDKIM_HDR_TAG;
- }
-
- if (where == PDKIM_HDR_TAG)
- {
- if (!cur_tag)
- cur_tag = pdkim_strnew(NULL);
-
- if (c >= 'a' && c <= 'z')
- pdkim_strncat(cur_tag, p, 1);
-
- if (c == '=')
- {
- where = PDKIM_HDR_VALUE;
- goto NEXT_CHAR;
- }
- }
+ const uschar * val;
- if (where == PDKIM_HDR_VALUE)
+ if ((val = Ustrchr(ele, '=')))
{
- if (!cur_val)
- cur_val = pdkim_strnew(NULL);
-
- if (c == '\r' || c == '\n')
- goto NEXT_CHAR;
+ int taglen = val++ - ele;
- if (c == ';' || c == '\0')
+ DEBUG(D_acl) debug_printf(" %.*s=%s\n", taglen, ele, val);
+ switch (ele[0])
{
- if (cur_tag->len > 0)
- {
- pdkim_strtrim(cur_val);
- DEBUG(D_acl) debug_printf(" %s=%s\n", cur_tag->str, cur_val->str);
-
- switch (cur_tag->str[0])
- {
- case 'v':
- /* This tag isn't evaluated because:
- - We only support version DKIM1.
- - Which is the default for this value (set below)
- - Other versions are currently not specified. */
- break;
- case 'h':
- pub->hashes = strdup(cur_val->str); break;
- case 'g':
- pub->granularity = strdup(cur_val->str); break;
- case 'n':
- pub->notes = pdkim_decode_qp(cur_val->str); break;
- case 'p':
- pdkim_decode_base64(US cur_val->str, &pub->key);
- break;
- case 'k':
- pub->hashes = strdup(cur_val->str); break;
- case 's':
- pub->srvtype = strdup(cur_val->str); break;
- case 't':
- if (strchr(cur_val->str, 'y') != NULL) pub->testing = 1;
- if (strchr(cur_val->str, 's') != NULL) pub->no_subdomaining = 1;
- break;
- default:
- DEBUG(D_acl) debug_printf(" Unknown tag encountered\n");
- break;
- }
- }
- pdkim_strclear(cur_tag);
- pdkim_strclear(cur_val);
- where = PDKIM_HDR_LIMBO;
+ case 'v': pub->version = val; break;
+ case 'h': pub->hashes = val; break;
+ case 'k': break;
+ case 'g': pub->granularity = val; break;
+ case 'n': pub->notes = pdkim_decode_qp(val); break;
+ case 'p': pdkim_decode_base64(val, &pub->key); break;
+ case 's': pub->srvtype = 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;
}
- else
- pdkim_strncat(cur_val, p, 1);
}
-
-NEXT_CHAR:
- if (c == '\0') break;
}
/* Set fallback defaults */
-if (!pub->version ) pub->version = strdup(PDKIM_PUB_RECORD_VERSION);
-if (!pub->granularity) pub->granularity = strdup("*");
-if (!pub->keytype ) pub->keytype = strdup("rsa");
-if (!pub->srvtype ) pub->srvtype = strdup("*");
+if (!pub->version ) pub->version = string_copy(PDKIM_PUB_RECORD_VERSION);
+else if (Ustrcmp(pub->version, PDKIM_PUB_RECORD_VERSION) != 0)
+ {
+ DEBUG(D_acl) debug_printf(" Bad v= field\n");
+ return NULL;
+ }
+
+if (!pub->granularity) pub->granularity = US"*";
+/*
+if (!pub->keytype ) pub->keytype = US"rsa";
+*/
+if (!pub->srvtype ) pub->srvtype = US"*";
/* p= is required */
if (pub->key.data)
return pub;
-pdkim_free_pubkey(pub);
+DEBUG(D_acl) debug_printf(" Missing p= field\n");
return NULL;
}
/* -------------------------------------------------------------------------- */
static int
-pdkim_update_bodyhash(pdkim_ctx *ctx, const char *data, int len)
+pdkim_update_bodyhash(pdkim_ctx * ctx, const char * data, int len)
{
-pdkim_signature *sig = ctx->sig;
-/* Cache relaxed version of data */
-char *relaxed_data = NULL;
-int relaxed_len = 0;
+pdkim_signature * sig;
+uschar * relaxed_data = NULL; /* Cache relaxed version of data */
+int relaxed_len = 0;
/* Traverse all signatures, updating their hashes. */
-while (sig)
+for (sig = ctx->sig; sig; sig = sig->next)
{
/* Defaults to simple canon (no further treatment necessary) */
- const char *canon_data = data;
- int canon_len = len;
+ const uschar *canon_data = CUS data;
+ int canon_len = len;
if (sig->canon_body == PDKIM_CANON_RELAXED)
{
const char *p;
int q = 0;
- if (!(relaxed_data = malloc(len+1)))
- return PDKIM_ERR_OOM;
+ /* We want to be able to free this else we allocate
+ for the entire message which could be many MB. Since
+ we don't know what allocations the SHA routines might
+ do, not safe to use store_get()/store_reset(). */
+
+ relaxed_data = store_malloc(len+1);
for (p = data; *p; p++)
{
if (canon_len > 0)
{
- exim_sha_update(&sig->body_hash, canon_data, canon_len);
+ exim_sha_update(&sig->body_hash_ctx, CUS canon_data, canon_len);
sig->signed_body_bytes += canon_len;
DEBUG(D_acl) pdkim_quoteprint(canon_data, canon_len);
}
-
- sig = sig->next;
}
-if (relaxed_data) free(relaxed_data);
+if (relaxed_data) store_free(relaxed_data);
return PDKIM_OK;
}
/* -------------------------------------------------------------------------- */
-static int
+static void
pdkim_finish_bodyhash(pdkim_ctx *ctx)
{
pdkim_signature *sig;
{ /* Finish hashes */
blob bh;
- exim_sha_finish(&sig->body_hash, &bh);
+ exim_sha_finish(&sig->body_hash_ctx, &bh);
DEBUG(D_acl)
{
debug_printf("PDKIM [%s] Body bytes hashed: %lu\n"
- "PDKIM [%s] bh computed: ",
+ "PDKIM [%s] Body hash computed: ",
sig->domain, sig->signed_body_bytes, sig->domain);
- pdkim_hexprint(CS bh.data, bh.len);
+ pdkim_hexprint(CUS bh.data, bh.len);
}
/* SIGNING -------------------------------------------------------------- */
- if (ctx->mode == PDKIM_MODE_SIGN)
+ if (ctx->flags & PDKIM_MODE_SIGN)
{
sig->bodyhash = bh;
sig->bodylength = -1;
}
- /* VERIFICATION --------------------------------------------------------- */
else
- {
- /* Compare bodyhash */
- if (memcmp(bh.data, sig->bodyhash.data, bh.len) == 0)
+ /* VERIFICATION --------------------------------------------------------- */
+ /* Be careful that the header sig included a bodyash */
+
+ if (sig->bodyhash.data && memcmp(bh.data, sig->bodyhash.data, bh.len) == 0)
{
DEBUG(D_acl) debug_printf("PDKIM [%s] Body hash verified OK\n", sig->domain);
}
{
DEBUG(D_acl)
{
- debug_printf("PDKIM [%s] bh signature: ", sig->domain);
- pdkim_hexprint(sig->bodyhash.data,
- exim_sha_hashlen(&sig->body_hash));
+ debug_printf("PDKIM [%s] Body hash signature from headers: ", sig->domain);
+ pdkim_hexprint(sig->bodyhash.data, sig->bodyhash.len);
debug_printf("PDKIM [%s] Body hash did NOT verify\n", sig->domain);
}
sig->verify_status = PDKIM_VERIFY_FAIL;
sig->verify_ext_status = PDKIM_VERIFY_FAIL_BODY;
}
- }
}
+}
+
+
+
+static int
+pdkim_body_complete(pdkim_ctx * ctx)
+{
+pdkim_signature * sig = ctx->sig; /*XXX assumes only one sig */
+/* In simple body mode, if any empty lines were buffered,
+replace with one. rfc 4871 3.4.3 */
+/*XXX checking the signed-body-bytes is a gross hack; I think
+it indicates that all linebreaks should be buffered, including
+the one terminating a text line */
+
+if ( sig && sig->canon_body == PDKIM_CANON_SIMPLE
+ && sig->signed_body_bytes == 0
+ && ctx->num_buffered_crlf > 0
+ )
+ pdkim_update_bodyhash(ctx, "\r\n", 2);
+
+ctx->flags |= PDKIM_SEEN_EOD;
+ctx->linebuf_offset = 0;
return PDKIM_OK;
}
/* -------------------------------------------------------------------------- */
-/* Callback from pdkim_feed below for processing complete body lines */
+/* Call from pdkim_feed below for processing complete body lines */
static int
pdkim_bodyline_complete(pdkim_ctx *ctx)
pdkim_signature *sig = ctx->sig; /*XXX assumes only one sig */
/* Ignore extra data if we've seen the end-of-data marker */
-if (ctx->seen_eod) goto BAIL;
+if (ctx->flags & PDKIM_SEEN_EOD) goto BAIL;
/* We've always got one extra byte to stuff a zero ... */
ctx->linebuf[ctx->linebuf_offset] = '\0';
/* Terminate on EOD marker */
-if (memcmp(p, ".\r\n", 3) == 0)
+if (ctx->flags & PDKIM_DOT_TERM)
{
- /* In simple body mode, if any empty lines were buffered,
- replace with one. rfc 4871 3.4.3 */
- /*XXX checking the signed-body-bytes is a gross hack; I think
- it indicates that all linebreaks should be buffered, including
- the one terminating a text line */
- if ( sig && sig->canon_body == PDKIM_CANON_SIMPLE
- && sig->signed_body_bytes == 0
- && ctx->num_buffered_crlf > 0
- )
- pdkim_update_bodyhash(ctx, "\r\n", 2);
+ if (memcmp(p, ".\r\n", 3) == 0)
+ return pdkim_body_complete(ctx);
- ctx->seen_eod = TRUE;
- goto BAIL;
- }
-/* Unstuff dots */
-if (memcmp(p, "..", 2) == 0)
- {
- p++;
- n--;
+ /* Unstuff dots */
+ if (memcmp(p, "..", 2) == 0)
+ {
+ p++;
+ n--;
+ }
}
/* Empty lines need to be buffered until we find a non-empty line */
#define DKIM_SIGNATURE_HEADERNAME "DKIM-Signature:"
static int
-pdkim_header_complete(pdkim_ctx *ctx)
+pdkim_header_complete(pdkim_ctx * ctx)
{
+pdkim_signature * sig, * last_sig;
+
/* Special case: The last header can have an extra \r appended */
-if ( (ctx->cur_header->len > 1) &&
- (ctx->cur_header->str[(ctx->cur_header->len)-1] == '\r') )
- {
- ctx->cur_header->str[(ctx->cur_header->len)-1] = '\0';
- ctx->cur_header->len--;
- }
+if ( (ctx->cur_header_len > 1) &&
+ (ctx->cur_header[(ctx->cur_header_len)-1] == '\r') )
+ --ctx->cur_header_len;
+ctx->cur_header[ctx->cur_header_len] = '\0';
-ctx->num_headers++;
-if (ctx->num_headers > PDKIM_MAX_HEADERS) goto BAIL;
+if (++ctx->num_headers > PDKIM_MAX_HEADERS) goto BAIL;
/* SIGNING -------------------------------------------------------------- */
-if (ctx->mode == PDKIM_MODE_SIGN)
- {
- pdkim_signature *sig;
-
+if (ctx->flags & PDKIM_MODE_SIGN)
for (sig = ctx->sig; sig; sig = sig->next) /* Traverse all signatures */
- if (header_name_match(ctx->cur_header->str,
- sig->sign_headers?
- sig->sign_headers:
- PDKIM_DEFAULT_SIGN_HEADERS, 0) == PDKIM_OK)
- {
- pdkim_stringlist *list;
- /* Add header to the signed headers list (in reverse order) */
- if (!(list = pdkim_prepend_stringlist(sig->headers,
- ctx->cur_header->str)))
- return PDKIM_ERR_OOM;
- sig->headers = list;
- }
- }
+ /* Add header to the signed headers list (in reverse order) */
+ sig->headers = pdkim_prepend_stringlist(sig->headers,
+ ctx->cur_header);
/* VERIFICATION ----------------------------------------------------------- */
/* DKIM-Signature: headers are added to the verification list */
-if (ctx->mode == PDKIM_MODE_VERIFY)
+else
{
- if (strncasecmp(ctx->cur_header->str,
+#ifdef notdef
+ DEBUG(D_acl)
+ {
+ debug_printf("PDKIM >> raw hdr: ");
+ pdkim_quoteprint(CUS ctx->cur_header, ctx->cur_header_len);
+ }
+#endif
+ if (strncasecmp(CCS ctx->cur_header,
DKIM_SIGNATURE_HEADERNAME,
- strlen(DKIM_SIGNATURE_HEADERNAME)) == 0)
+ Ustrlen(DKIM_SIGNATURE_HEADERNAME)) == 0)
{
- pdkim_signature *new_sig;
+ /* Create and chain new signature block. We could error-check for all
+ required tags here, but prefer to create the internal sig and expicitly
+ fail verification of it later. */
- /* Create and chain new signature block */
DEBUG(D_acl) debug_printf(
"PDKIM >> Found sig, trying to parse >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
- if ((new_sig = pdkim_parse_sig_header(ctx, ctx->cur_header->str)))
+ sig = pdkim_parse_sig_header(ctx, ctx->cur_header);
+
+ if (!(last_sig = ctx->sig))
+ ctx->sig = sig;
+ else
{
- pdkim_signature *last_sig = ctx->sig;
- if (!last_sig)
- ctx->sig = new_sig;
- else
- {
- while (last_sig->next) last_sig = last_sig->next;
- last_sig->next = new_sig;
- }
+ while (last_sig->next) last_sig = last_sig->next;
+ last_sig->next = sig;
}
- else
- DEBUG(D_acl) debug_printf(
- "Error while parsing signature header\n"
- "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
}
- /* every other header is stored for signature verification */
- else
- {
- pdkim_stringlist *list;
-
- if (!(list = pdkim_prepend_stringlist(ctx->headers, ctx->cur_header->str)))
- return PDKIM_ERR_OOM;
- ctx->headers = list;
- }
+ /* all headers are stored for signature verification */
+ ctx->headers = pdkim_prepend_stringlist(ctx->headers, ctx->cur_header);
}
BAIL:
-pdkim_strclear(ctx->cur_header); /* Re-use existing pdkim_str */
+ctx->cur_header[ctx->cur_header_len = 0] = '\0'; /* leave buffer for reuse */
return PDKIM_OK;
}
#define HEADER_BUFFER_FRAG_SIZE 256
DLLEXPORT int
-pdkim_feed (pdkim_ctx *ctx, char *data, int len)
+pdkim_feed(pdkim_ctx * ctx, uschar * data, int len)
{
-int p;
+int p, rc;
+
+/* Alternate EOD signal, used in non-dotstuffing mode */
+if (!data)
+ pdkim_body_complete(ctx);
-for (p = 0; p<len; p++)
+else for (p = 0; p<len; p++)
{
- char c = data[p];
+ uschar c = data[p];
- if (ctx->past_headers)
+ if (ctx->flags & PDKIM_PAST_HDRS)
{
+ if (c == '\n' && !(ctx->flags & PDKIM_SEEN_CR)) /* emulate the CR */
+ {
+ ctx->linebuf[ctx->linebuf_offset++] = '\r';
+ if (ctx->linebuf_offset == PDKIM_MAX_BODY_LINE_LEN-1)
+ return PDKIM_ERR_LONG_LINE;
+ }
+
/* Processing body byte */
ctx->linebuf[ctx->linebuf_offset++] = c;
- if (c == '\n')
+ if (c == '\r')
+ ctx->flags |= PDKIM_SEEN_CR;
+ else if (c == '\n')
{
- int rc = pdkim_bodyline_complete(ctx); /* End of line */
- if (rc != PDKIM_OK) return rc;
+ ctx->flags &= ~PDKIM_SEEN_CR;
+ if ((rc = pdkim_bodyline_complete(ctx)) != PDKIM_OK)
+ return rc;
}
- if (ctx->linebuf_offset == (PDKIM_MAX_BODY_LINE_LEN-1))
+
+ if (ctx->linebuf_offset == PDKIM_MAX_BODY_LINE_LEN-1)
return PDKIM_ERR_LONG_LINE;
}
else
{
/* Processing header byte */
- if (c != '\r')
+ if (c == '\r')
+ ctx->flags |= PDKIM_SEEN_CR;
+ else if (c == '\n')
{
- if (c == '\n')
- {
- if (ctx->seen_lf)
- {
- int rc = pdkim_header_complete(ctx); /* Seen last header line */
- if (rc != PDKIM_OK) return rc;
-
- ctx->past_headers = TRUE;
- ctx->seen_lf = 0;
- DEBUG(D_acl) debug_printf(
- "PDKIM >> Hashed body data, canonicalized >>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
- continue;
- }
- else
- ctx->seen_lf = TRUE;
- }
- else if (ctx->seen_lf)
- {
- if (!(c == '\t' || c == ' '))
- {
- int rc = pdkim_header_complete(ctx); /* End of header */
- if (rc != PDKIM_OK) return rc;
- }
- ctx->seen_lf = FALSE;
+ if (!(ctx->flags & PDKIM_SEEN_CR)) /* emulate the CR */
+ ctx->cur_header = string_catn(ctx->cur_header, &ctx->cur_header_size,
+ &ctx->cur_header_len, CUS "\r", 1);
+
+ if (ctx->flags & PDKIM_SEEN_LF) /* Seen last header line */
+ {
+ if ((rc = pdkim_header_complete(ctx)) != PDKIM_OK)
+ return rc;
+
+ ctx->flags = (ctx->flags & ~(PDKIM_SEEN_LF|PDKIM_SEEN_CR)) | PDKIM_PAST_HDRS;
+ DEBUG(D_acl) debug_printf(
+ "PDKIM >> Body data for hash, canonicalized >>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
+ continue;
}
+ else
+ ctx->flags = (ctx->flags & ~PDKIM_SEEN_CR) | PDKIM_SEEN_LF;
+ }
+ else if (ctx->flags & PDKIM_SEEN_LF)
+ {
+ if (!(c == '\t' || c == ' ')) /* End of header */
+ if ((rc = pdkim_header_complete(ctx)) != PDKIM_OK)
+ return rc;
+ ctx->flags &= ~PDKIM_SEEN_LF;
}
- if (!ctx->cur_header)
- if (!(ctx->cur_header = pdkim_strnew(NULL)))
- return PDKIM_ERR_OOM;
-
- if (ctx->cur_header->len < PDKIM_MAX_HEADER_LEN)
- if (!pdkim_strncat(ctx->cur_header, &data[p], 1))
- return PDKIM_ERR_OOM;
+ if (ctx->cur_header_len < PDKIM_MAX_HEADER_LEN)
+ ctx->cur_header = string_catn(ctx->cur_header, &ctx->cur_header_size,
+ &ctx->cur_header_len, CUS &data[p], 1);
}
}
return PDKIM_OK;
}
+
+
+/* Extend a grwong header with a continuation-linebreak */
+static uschar *
+pdkim_hdr_cont(uschar * str, int * size, int * ptr, int * col)
+{
+*col = 1;
+return string_catn(str, size, ptr, US"\r\n\t", 3);
+}
+
+
+
/*
* RFC 5322 specifies that header line length SHOULD be no more than 78
* lets make it so!
* pdkim_headcat
- * returns char*
+ *
+ * returns uschar * (not nul-terminated)
*
* col: this int holds and receives column number (octets since last '\n')
* str: partial string to append to
+ * size: current buffer size for str
+ * ptr: current tail-pointer for str
* pad: padding, split line or space after before or after eg: ";"
* intro: - must join to payload eg "h=", usually the tag name
* payload: eg base64 data - long data can be split arbitrarily.
* names longer than 78, or bogus col. Input is assumed to be free of line breaks.
*/
-static char *
-pdkim_headcat(int *col, pdkim_str *str, const char * pad,
- const char *intro, const char *payload)
+static uschar *
+pdkim_headcat(int * col, uschar * str, int * size, int * ptr,
+ const uschar * pad, const uschar * intro, const uschar * payload)
{
size_t l;
if (pad)
{
- l = strlen(pad);
+ l = Ustrlen(pad);
if (*col + l > 78)
- {
- pdkim_strcat(str, "\r\n\t");
- *col = 1;
- }
- pdkim_strncat(str, pad, l);
+ str = pdkim_hdr_cont(str, size, ptr, col);
+ str = string_catn(str, size, ptr, pad, l);
*col += l;
}
-l = (pad?1:0) + (intro?strlen(intro):0);
+l = (pad?1:0) + (intro?Ustrlen(intro):0);
if (*col + l > 78)
{ /*can't fit intro - start a new line to make room.*/
- pdkim_strcat(str, "\r\n\t");
- *col = 1;
- l = intro?strlen(intro):0;
+ str = pdkim_hdr_cont(str, size, ptr, col);
+ l = intro?Ustrlen(intro):0;
}
-l += payload ? strlen(payload):0 ;
+l += payload ? Ustrlen(payload):0 ;
while (l>77)
{ /* this fragment will not fit on a single line */
if (pad)
{
- pdkim_strcat(str, " ");
+ str = string_catn(str, size, ptr, US" ", 1);
*col += 1;
pad = NULL; /* only want this once */
l--;
if (intro)
{
- size_t sl = strlen(intro);
+ size_t sl = Ustrlen(intro);
- pdkim_strncat(str, intro, sl);
+ str = string_catn(str, size, ptr, intro, sl);
*col += sl;
l -= sl;
intro = NULL; /* only want this once */
if (payload)
{
- size_t sl = strlen(payload);
+ size_t sl = Ustrlen(payload);
size_t chomp = *col+sl < 77 ? sl : 78-*col;
- pdkim_strncat(str, payload, chomp);
+ str = string_catn(str, size, ptr, payload, chomp);
*col += chomp;
payload += chomp;
l -= chomp-1;
}
/* the while precondition tells us it didn't fit. */
- pdkim_strcat(str, "\r\n\t");
- *col = 1;
+ str = pdkim_hdr_cont(str, size, ptr, col);
}
if (*col + l > 78)
{
- pdkim_strcat(str, "\r\n\t");
- *col = 1;
+ str = pdkim_hdr_cont(str, size, ptr, col);
pad = NULL;
}
if (pad)
{
- pdkim_strcat(str, " ");
+ str = string_catn(str, size, ptr, US" ", 1);
*col += 1;
pad = NULL;
}
if (intro)
{
- size_t sl = strlen(intro);
+ size_t sl = Ustrlen(intro);
- pdkim_strncat(str, intro, sl);
+ str = string_catn(str, size, ptr, intro, sl);
*col += sl;
l -= sl;
intro = NULL;
if (payload)
{
- size_t sl = strlen(payload);
+ size_t sl = Ustrlen(payload);
- pdkim_strncat(str, payload, sl);
+ str = string_catn(str, size, ptr, payload, sl);
*col += sl;
}
-return str->str;
+return str;
}
/* -------------------------------------------------------------------------- */
-static char *
+static uschar *
pdkim_create_header(pdkim_signature *sig, BOOL final)
{
-char *rc = NULL;
-char *base64_bh = NULL;
-char *base64_b = NULL;
+uschar * base64_bh;
+uschar * base64_b;
int col = 0;
-pdkim_str *hdr;
-pdkim_str *canon_all;
-
-if (!(hdr = pdkim_strnew("DKIM-Signature: v="PDKIM_SIGNATURE_VERSION)))
- return NULL;
+uschar * hdr; int hdr_size = 0, hdr_len = 0;
+uschar * canon_all; int can_size = 0, can_len = 0;
-if (!(canon_all = pdkim_strnew(pdkim_canons[sig->canon_headers])))
- goto BAIL;
-
-if (!(base64_bh = pdkim_encode_base64(&sig->bodyhash)))
- goto BAIL;
+canon_all = string_cat (NULL, &can_size, &can_len,
+ pdkim_canons[sig->canon_headers]);
+canon_all = string_catn(canon_all, &can_size, &can_len, US"/", 1);
+canon_all = string_cat (canon_all, &can_size, &can_len,
+ pdkim_canons[sig->canon_body]);
+canon_all[can_len] = '\0';
-col = strlen(hdr->str);
+hdr = string_cat(NULL, &hdr_size, &hdr_len,
+ US"DKIM-Signature: v="PDKIM_SIGNATURE_VERSION);
+col = hdr_len;
/* Required and static bits */
-if ( pdkim_headcat(&col, hdr, ";", "a=", pdkim_algos[sig->algo])
- && pdkim_headcat(&col, hdr, ";", "q=", pdkim_querymethods[sig->querymethod])
- && pdkim_strcat(canon_all, "/")
- && pdkim_strcat(canon_all, pdkim_canons[sig->canon_body])
- && pdkim_headcat(&col, hdr, ";", "c=", canon_all->str)
- && pdkim_headcat(&col, hdr, ";", "d=", sig->domain)
- && pdkim_headcat(&col, hdr, ";", "s=", sig->selector)
- )
+hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"a=",
+/*XXX this is a combo of algo and hash-method */
+ pdkim_algos[sig->algo]);
+hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"q=",
+ pdkim_querymethods[sig->querymethod]);
+hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"c=",
+ canon_all);
+hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"d=",
+ sig->domain);
+hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"s=",
+ sig->selector);
+
+/* list of header names can be split between items. */
{
- /* list of header names can be split between items. */
- {
- char *n = CS string_copy(sig->headernames);
- char *f = n;
- char *i = "h=";
- char *s = ";";
+ uschar * n = string_copy(sig->headernames);
+ uschar * i = US"h=";
+ uschar * s = US";";
- if (!n) goto BAIL;
- while (*n)
- {
- char *c = strchr(n, ':');
+ while (*n)
+ {
+ uschar * c = Ustrchr(n, ':');
- if (c) *c ='\0';
+ if (c) *c ='\0';
- if (!i)
- if (!pdkim_headcat(&col, hdr, NULL, NULL, ":"))
- {
- goto BAIL;
- }
+ if (!i)
+ hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, NULL, NULL, US":");
- if (!pdkim_headcat(&col, hdr, s, i, n))
- {
- goto BAIL;
- }
+ hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, s, i, n);
- if (!c)
- break;
+ if (!c)
+ break;
- n = c+1;
- s = NULL;
- i = NULL;
- }
+ n = c+1;
+ s = NULL;
+ i = NULL;
}
+ }
- if(!pdkim_headcat(&col, hdr, ";", "bh=", base64_bh))
- goto BAIL;
+base64_bh = pdkim_encode_base64(&sig->bodyhash);
+hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"bh=", base64_bh);
- /* Optional bits */
- if (sig->identity)
- if(!pdkim_headcat(&col, hdr, ";", "i=", sig->identity))
- goto BAIL;
+/* Optional bits */
+if (sig->identity)
+ hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"i=", sig->identity);
- if (sig->created > 0)
- {
- char minibuf[20];
+if (sig->created > 0)
+ {
+ uschar minibuf[20];
- snprintf(minibuf, 20, "%lu", sig->created);
- if(!pdkim_headcat(&col, hdr, ";", "t=", minibuf))
- goto BAIL;
+ snprintf(CS minibuf, sizeof(minibuf), "%lu", sig->created);
+ hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"t=", minibuf);
+}
+
+if (sig->expires > 0)
+ {
+ uschar minibuf[20];
+
+ snprintf(CS minibuf, sizeof(minibuf), "%lu", sig->expires);
+ hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"x=", minibuf);
}
- if (sig->expires > 0)
- {
- char minibuf[20];
+if (sig->bodylength >= 0)
+ {
+ uschar minibuf[20];
- snprintf(minibuf, 20, "%lu", sig->expires);
- if(!pdkim_headcat(&col, hdr, ";", "x=", minibuf))
- goto BAIL;
- }
+ snprintf(CS minibuf, sizeof(minibuf), "%lu", sig->bodylength);
+ hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"l=", minibuf);
+ }
- if (sig->bodylength >= 0)
- {
- char minibuf[20];
+/* Preliminary or final version? */
+if (final)
+ {
+ base64_b = pdkim_encode_base64(&sig->sighash);
+ hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"b=", base64_b);
- snprintf(minibuf, 20, "%lu", sig->bodylength);
- if(!pdkim_headcat(&col, hdr, ";", "l=", minibuf))
- goto BAIL;
- }
+ /* add trailing semicolon: I'm not sure if this is actually needed */
+ hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, NULL, US";", US"");
+ }
+else
+ {
+ /* To satisfy the rule "all surrounding whitespace [...] deleted"
+ ( RFC 6376 section 3.7 ) we ensure there is no whitespace here. Otherwise
+ the headcat routine could insert a linebreak which the relaxer would reduce
+ to a single space preceding the terminating semicolon, resulting in an
+ incorrect header-hash. */
+ hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"b=;", US"");
+ }
- /* Preliminary or final version? */
- if (final)
- {
- if (!(base64_b = pdkim_encode_base64(&sig->sigdata)))
- goto BAIL;
- if (!pdkim_headcat(&col, hdr, ";", "b=", base64_b))
- goto BAIL;
+hdr[hdr_len] = '\0';
+return hdr;
+}
+
+
+/* -------------------------------------------------------------------------- */
+
+static pdkim_pubkey *
+pdkim_key_from_dns(pdkim_ctx * ctx, pdkim_signature * sig, ev_ctx * vctx,
+ const uschar ** errstr)
+{
+uschar * dns_txt_name, * dns_txt_reply;
+pdkim_pubkey * p;
+
+/* Fetch public key for signing domain, from DNS */
+
+dns_txt_name = string_sprintf("%s._domainkey.%s.", sig->selector, sig->domain);
+
+dns_txt_reply = store_get(PDKIM_DNS_TXT_MAX_RECLEN);
+memset(dns_txt_reply, 0, PDKIM_DNS_TXT_MAX_RECLEN);
+
+if ( ctx->dns_txt_callback(CS dns_txt_name, CS dns_txt_reply) != PDKIM_OK
+ || dns_txt_reply[0] == '\0'
+ )
+ {
+ sig->verify_status = PDKIM_VERIFY_INVALID;
+ sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE;
+ return NULL;
}
- else
- if(!pdkim_headcat(&col, hdr, ";", "b=", ""))
- goto BAIL;
- /* add trailing semicolon: I'm not sure if this is actually needed */
- if (!pdkim_headcat(&col, hdr, NULL, ";", ""))
- goto BAIL;
+DEBUG(D_acl)
+ {
+ debug_printf(
+ "PDKIM >> Parsing public key record >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n"
+ " Raw record: ");
+ pdkim_quoteprint(CUS dns_txt_reply, Ustrlen(dns_txt_reply));
}
-rc = strdup(hdr->str);
+if ( !(p = pdkim_parse_pubkey_record(ctx, CUS dns_txt_reply))
+ || (Ustrcmp(p->srvtype, "*") != 0 && Ustrcmp(p->srvtype, "email") != 0)
+ )
+ {
+ sig->verify_status = PDKIM_VERIFY_INVALID;
+ sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD;
-BAIL:
-pdkim_strfree(hdr);
-if (canon_all) pdkim_strfree(canon_all);
-return rc;
+ DEBUG(D_acl)
+ {
+ if (p)
+ debug_printf(" Invalid public key service type '%s'\n", p->srvtype);
+ else
+ debug_printf(" Error while parsing public key record\n");
+ debug_printf(
+ "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
+ }
+ return NULL;
+ }
+
+DEBUG(D_acl) debug_printf(
+ "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
+
+/* Import public key */
+if ((*errstr = exim_dkim_verify_init(&p->key, vctx)))
+ {
+ DEBUG(D_acl) debug_printf("verify_init: %s\n", *errstr);
+ sig->verify_status = PDKIM_VERIFY_INVALID;
+ sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_IMPORT;
+ return NULL;
+ }
+
+return p;
}
/* -------------------------------------------------------------------------- */
DLLEXPORT int
-pdkim_feed_finish(pdkim_ctx *ctx, pdkim_signature **return_signatures)
+pdkim_feed_finish(pdkim_ctx * ctx, pdkim_signature ** return_signatures,
+ const uschar ** err)
{
pdkim_signature *sig = ctx->sig;
-pdkim_str *headernames = NULL; /* Collected signed header names */
/* Check if we must still flush a (partial) header. If that is the
case, the message has no body, and we must compute a body hash
out of '<CR><LF>' */
-if (ctx->cur_header && ctx->cur_header->len)
+if (ctx->cur_header && ctx->cur_header_len)
{
int rc = pdkim_header_complete(ctx);
if (rc != PDKIM_OK) return rc;
"PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
/* Build (and/or evaluate) body hash */
-if (pdkim_finish_bodyhash(ctx) != PDKIM_OK)
- return PDKIM_ERR_OOM;
-
-/* SIGNING -------------------------------------------------------------- */
-if (ctx->mode == PDKIM_MODE_SIGN)
- if (!(headernames = pdkim_strnew(NULL)))
- return PDKIM_ERR_OOM;
-/* ---------------------------------------------------------------------- */
+pdkim_finish_bodyhash(ctx);
while (sig)
{
+/*XXX bool probably not enough */
BOOL is_sha1 = sig->algo == PDKIM_ALGO_RSA_SHA1;
hctx hhash_ctx;
- char * sig_hdr;
+ uschar * sig_hdr = US"";
blob hhash;
blob hdata;
int hdata_alloc = 0;
hdata.data = NULL;
hdata.len = 0;
- exim_sha_init(&hhash_ctx, is_sha1);
+ if (!exim_sha_init(&hhash_ctx, is_sha1 ? HASH_SHA1 : HASH_SHA256))
+ {
+ DEBUG(D_acl) debug_printf("PDKIM: hask setup internal error\n");
+ break;
+ }
DEBUG(D_acl) debug_printf(
- "PDKIM >> Hashed header data, canonicalized, in sequence >>>>>>>>>>>>>>\n");
+ "PDKIM >> Header data for hash, canonicalized, in sequence >>>>>>>>>>>>\n");
/* SIGNING ---------------------------------------------------------------- */
/* When signing, walk through our header list and add them to the hash. As we
- go, construct a list of the header's names to use for the h= parameter. */
+ go, construct a list of the header's names to use for the h= parameter.
+ Then append to that list any remaining header names for which there was no
+ header to sign. */
- if (ctx->mode == PDKIM_MODE_SIGN)
+ if (ctx->flags & PDKIM_MODE_SIGN)
{
+ uschar * headernames = NULL; /* Collected signed header names */
+ int hs = 0, hl = 0;
pdkim_stringlist *p;
+ const uschar * l;
+ uschar * s;
+ int sep = 0;
for (p = sig->headers; p; p = p->next)
- {
- uschar * rh;
- /* Collect header names (Note: colon presence is guaranteed here) */
- uschar * q = Ustrchr(p->value, ':');
+ if (header_name_match(p->value, sig->sign_headers) == PDKIM_OK)
+ {
+ uschar * rh;
+ /* Collect header names (Note: colon presence is guaranteed here) */
+ uschar * q = Ustrchr(p->value, ':');
- if (!(pdkim_strncat(headernames, p->value,
- (q-US (p->value)) + (p->next ? 1 : 0))))
- return PDKIM_ERR_OOM;
+ headernames = string_catn(headernames, &hs, &hl,
+ p->value, (q - US p->value) + (p->next ? 1 : 0));
- rh = sig->canon_headers == PDKIM_CANON_RELAXED
- ? US pdkim_relax_header(p->value, 1) /* cook header for relaxed canon */
- : string_copy(p->value); /* just copy it for simple canon */
- if (!rh)
- return PDKIM_ERR_OOM;
+ rh = sig->canon_headers == PDKIM_CANON_RELAXED
+ ? pdkim_relax_header(p->value, TRUE) /* cook header for relaxed canon */
+ : string_copy(CUS p->value); /* just copy it for simple canon */
- /* Feed header to the hash algorithm */
- exim_sha_update(&hhash_ctx, rh, strlen(rh));
+ /* Feed header to the hash algorithm */
+ exim_sha_update(&hhash_ctx, CUS rh, Ustrlen(rh));
- /* Remember headers block for signing (when the library cannot do incremental) */
- (void) exim_rsa_data_append(&hdata, &hdata_alloc, rh);
+ /* Remember headers block for signing (when the library cannot do incremental) */
+ (void) exim_dkim_data_append(&hdata, &hdata_alloc, rh);
- DEBUG(D_acl) pdkim_quoteprint(rh, Ustrlen(rh));
- }
+ DEBUG(D_acl) pdkim_quoteprint(rh, Ustrlen(rh));
+ }
+
+ l = sig->sign_headers;
+ while((s = string_nextinlist(&l, &sep, NULL, 0)))
+ if (*s != '_')
+ { /*SSS string_append_listele() */
+ if (hl > 0 && headernames[hl-1] != ':')
+ headernames = string_catn(headernames, &hs, &hl, US":", 1);
+
+ headernames = string_cat(headernames, &hs, &hl, s);
+ }
+ headernames[hl] = '\0';
+
+ /* Copy headernames to signature struct */
+ sig->headernames = headernames;
+
+ /* Create signature header with b= omitted */
+ sig_hdr = pdkim_create_header(sig, FALSE);
}
/* VERIFICATION ----------------------------------------------------------- */
add the headers to the hash in that order. */
else
{
- uschar * b = string_copy(sig->headernames);
- uschar * p = b;
+ uschar * p = sig->headernames;
uschar * q;
pdkim_stringlist * hdrs;
- if (!b) return PDKIM_ERR_OOM;
-
- /* clear tags */
- for (hdrs = ctx->headers; hdrs; hdrs = hdrs->next)
- hdrs->tag = 0;
-
- while(1)
+ if (p)
{
- if ((q = Ustrchr(p, ':')))
- *q = '\0';
-
+ /* clear tags */
for (hdrs = ctx->headers; hdrs; hdrs = hdrs->next)
- if ( hdrs->tag == 0
- && strncasecmp(hdrs->value, CS p, Ustrlen(p)) == 0
- && (hdrs->value)[Ustrlen(p)] == ':'
- )
- {
- uschar * rh = sig->canon_headers == PDKIM_CANON_RELAXED
- ? US pdkim_relax_header(hdrs->value, 1) /* cook header for relaxed canon */
- : string_copy(hdrs->value); /* just copy it for simple canon */
- if (!rh)
- return PDKIM_ERR_OOM;
-
- /* Feed header to the hash algorithm */
- exim_sha_update(&hhash_ctx, rh, strlen(rh));
-
- DEBUG(D_acl) pdkim_quoteprint(rh, Ustrlen(rh));
- hdrs->tag = 1;
- break;
- }
+ hdrs->tag = 0;
+
+ p = string_copy(p);
+ while(1)
+ {
+ if ((q = Ustrchr(p, ':')))
+ *q = '\0';
+
+ /*XXX walk the list of headers in same order as received. */
+ for (hdrs = ctx->headers; hdrs; hdrs = hdrs->next)
+ if ( hdrs->tag == 0
+ && strncasecmp(CCS hdrs->value, CCS p, Ustrlen(p)) == 0
+ && (hdrs->value)[Ustrlen(p)] == ':'
+ )
+ {
+ /* cook header for relaxed canon, or just copy it for simple */
+
+ uschar * rh = sig->canon_headers == PDKIM_CANON_RELAXED
+ ? pdkim_relax_header(hdrs->value, TRUE)
+ : string_copy(CUS hdrs->value);
+
+ /* Feed header to the hash algorithm */
+ exim_sha_update(&hhash_ctx, CUS rh, Ustrlen(rh));
+
+ DEBUG(D_acl) pdkim_quoteprint(rh, Ustrlen(rh));
+ hdrs->tag = 1;
+ break;
+ }
- if (!q) break;
- p = q+1;
+ if (!q) break;
+ p = q+1;
+ }
+
+ sig_hdr = string_copy(sig->rawsig_no_b_val);
}
}
DEBUG(D_acl) debug_printf(
"PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
- /* SIGNING ---------------------------------------------------------------- */
- if (ctx->mode == PDKIM_MODE_SIGN)
- {
- /* Copy headernames to signature struct */
- sig->headernames = string_copy(US headernames->str);
- pdkim_strfree(headernames);
-
- /* Create signature header with b= omitted */
- sig_hdr = pdkim_create_header(ctx->sig, FALSE);
- }
-
- /* VERIFICATION ----------------------------------------------------------- */
- else
- sig_hdr = strdup(sig->rawsig_no_b_val);
- /* ------------------------------------------------------------------------ */
-
- if (!sig_hdr)
- return PDKIM_ERR_OOM;
-
/* Relax header if necessary */
if (sig->canon_headers == PDKIM_CANON_RELAXED)
- {
- char *relaxed_hdr = pdkim_relax_header(sig_hdr, 0);
-
- free(sig_hdr);
- if (!relaxed_hdr)
- return PDKIM_ERR_OOM;
- sig_hdr = relaxed_hdr;
- }
+ sig_hdr = pdkim_relax_header(sig_hdr, FALSE);
DEBUG(D_acl)
{
debug_printf(
"PDKIM >> Signed DKIM-Signature header, canonicalized >>>>>>>>>>>>>>>>>\n");
- pdkim_quoteprint(sig_hdr, strlen(sig_hdr));
+ pdkim_quoteprint(CUS sig_hdr, Ustrlen(sig_hdr));
debug_printf(
"PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
}
/* Finalize header hash */
- exim_sha_update(&hhash_ctx, sig_hdr, strlen(sig_hdr));
+ exim_sha_update(&hhash_ctx, CUS sig_hdr, Ustrlen(sig_hdr));
exim_sha_finish(&hhash_ctx, &hhash);
DEBUG(D_acl)
{
- debug_printf("PDKIM [%s] hh computed: ", sig->domain);
+ debug_printf("PDKIM [%s] Header hash computed: ", sig->domain);
pdkim_hexprint(hhash.data, hhash.len);
}
/* Remember headers block for signing (when the library cannot do incremental) */
- if (ctx->mode == PDKIM_MODE_SIGN)
- (void) exim_rsa_data_append(&hdata, &hdata_alloc, sig_hdr);
-
- free(sig_hdr);
+/*XXX is this assuing algo == RSA? */
+ if (ctx->flags & PDKIM_MODE_SIGN)
+ (void) exim_dkim_data_append(&hdata, &hdata_alloc, US sig_hdr);
/* SIGNING ---------------------------------------------------------------- */
- if (ctx->mode == PDKIM_MODE_SIGN)
+ if (ctx->flags & PDKIM_MODE_SIGN)
{
es_ctx sctx;
- const uschar * errstr;
/* Import private key */
- if ((errstr = exim_rsa_signing_init(sig->rsa_privkey, &sctx)))
+/*XXX extend for non-RSA algos */
+ if ((*err = exim_dkim_signing_init(US sig->rsa_privkey, &sctx)))
{
- DEBUG(D_acl) debug_printf("signing_init: %s\n", errstr);
+ DEBUG(D_acl) debug_printf("signing_init: %s\n", *err);
return PDKIM_ERR_RSA_PRIVKEY;
}
hdata = hhash;
#endif
- if ((errstr = exim_rsa_sign(&sctx, is_sha1, &hdata, &sig->sigdata)))
+/*XXX extend for non-RSA algos */
+/*XXX oddly the dkim rfc does _not_ say what variant (sha1 or sha256) of
+RSA signing should be done. We use the same variant as the hash-method. */
+
+ if ((*err = exim_dkim_sign(&sctx, is_sha1, &hdata, &sig->sighash)))
{
- DEBUG(D_acl) debug_printf("signing: %s\n", errstr);
+ DEBUG(D_acl) debug_printf("signing: %s\n", *err);
return PDKIM_ERR_RSA_SIGNING;
}
DEBUG(D_acl)
{
debug_printf( "PDKIM [%s] b computed: ", sig->domain);
- pdkim_hexprint(sig->sigdata.data, sig->sigdata.len);
+ pdkim_hexprint(sig->sighash.data, sig->sighash.len);
}
- if (!(sig->signature_header = pdkim_create_header(ctx->sig, TRUE)))
- return PDKIM_ERR_OOM;
+ sig->signature_header = pdkim_create_header(sig, TRUE);
}
/* VERIFICATION ----------------------------------------------------------- */
else
{
ev_ctx vctx;
- const uschar * errstr;
-
- char *dns_txt_name, *dns_txt_reply;
- /* Fetch public key for signing domain, from DNS */
-
- if (!(dns_txt_name = malloc(PDKIM_DNS_TXT_MAX_NAMELEN)))
- return PDKIM_ERR_OOM;
-
- if (!(dns_txt_reply = malloc(PDKIM_DNS_TXT_MAX_RECLEN)))
+ /* Make sure we have all required signature tags */
+ if (!( sig->domain && *sig->domain
+ && sig->selector && *sig->selector
+ && sig->headernames && *sig->headernames
+ && sig->bodyhash.data
+ && sig->sighash.data
+ && sig->algo > -1
+ && sig->version
+ ) )
{
- free(dns_txt_name);
- return PDKIM_ERR_OOM;
- }
-
- memset(dns_txt_reply, 0, PDKIM_DNS_TXT_MAX_RECLEN);
- memset(dns_txt_name , 0, PDKIM_DNS_TXT_MAX_NAMELEN);
+ sig->verify_status = PDKIM_VERIFY_INVALID;
+ sig->verify_ext_status = PDKIM_VERIFY_INVALID_SIGNATURE_ERROR;
- if (snprintf(dns_txt_name, PDKIM_DNS_TXT_MAX_NAMELEN,
- "%s._domainkey.%s.",
- sig->selector, sig->domain) >= PDKIM_DNS_TXT_MAX_NAMELEN)
- {
- sig->verify_status = PDKIM_VERIFY_INVALID;
- sig->verify_ext_status = PDKIM_VERIFY_INVALID_BUFFER_SIZE;
- goto NEXT_VERIFY;
- }
-
- if ( ctx->dns_txt_callback(dns_txt_name, dns_txt_reply) != PDKIM_OK
- || dns_txt_reply[0] == '\0')
- {
- sig->verify_status = PDKIM_VERIFY_INVALID;
- sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE;
+ DEBUG(D_acl) debug_printf(
+ " Error in DKIM-Signature header: tags missing or invalid\n"
+ "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
goto NEXT_VERIFY;
}
- DEBUG(D_acl)
- {
- debug_printf(
- "PDKIM >> Parsing public key record >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n"
- " Raw record: ");
- pdkim_quoteprint(dns_txt_reply, strlen(dns_txt_reply));
- }
-
- if (!(sig->pubkey = pdkim_parse_pubkey_record(ctx, dns_txt_reply)))
+ /* Make sure sig uses supported DKIM version (only v1) */
+ if (sig->version != 1)
{
- sig->verify_status = PDKIM_VERIFY_INVALID;
- sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD;
+ sig->verify_status = PDKIM_VERIFY_INVALID;
+ sig->verify_ext_status = PDKIM_VERIFY_INVALID_DKIM_VERSION;
DEBUG(D_acl) debug_printf(
- " Error while parsing public key record\n"
- "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
+ " Error in DKIM-Signature header: unsupported DKIM version\n"
+ "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
goto NEXT_VERIFY;
}
- DEBUG(D_acl) debug_printf(
- "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
+ if (!(sig->pubkey = pdkim_key_from_dns(ctx, sig, &vctx, err)))
+ goto NEXT_VERIFY;
+
+ /* If the pubkey limits to a list of specific hashes, ignore sigs that
+ do not have the hash part of the sig algorithm matching */
- /* Import public key */
- if ((errstr = exim_rsa_verify_init(&sig->pubkey->key, &vctx)))
+ if (sig->pubkey->hashes)
{
- DEBUG(D_acl) debug_printf("verify_init: %s\n", errstr);
- sig->verify_status = PDKIM_VERIFY_INVALID;
- sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_IMPORT;
- goto NEXT_VERIFY;
+ const uschar * list = sig->pubkey->hashes, * ele;
+ int sep = ':';
+ while ((ele = string_nextinlist(&list, &sep, NULL, 0)))
+ if (Ustrcmp(ele, pdkim_algos[sig->algo] + 4) == 0) break;
+ if (!ele)
+ {
+ DEBUG(D_acl) debug_printf("pubkey h=%s vs sig a=%s\n",
+ sig->pubkey->hashes, pdkim_algos[sig->algo]);
+ sig->verify_status = PDKIM_VERIFY_FAIL;
+ sig->verify_ext_status = PDKIM_VERIFY_FAIL_SIG_ALGO_MISMATCH;
+ goto NEXT_VERIFY;
+ }
}
/* Check the signature */
- if ((errstr = exim_rsa_verify(&vctx, is_sha1, &hhash, &sig->sigdata)))
+/*XXX needs extension for non-RSA */
+ if ((*err = exim_dkim_verify(&vctx, is_sha1, &hhash, &sig->sighash)))
{
- DEBUG(D_acl) debug_printf("headers verify: %s\n", errstr);
+ DEBUG(D_acl) debug_printf("headers verify: %s\n", *err);
sig->verify_status = PDKIM_VERIFY_FAIL;
sig->verify_ext_status = PDKIM_VERIFY_FAIL_MESSAGE;
goto NEXT_VERIFY;
}
- /* We have a winner! (if bodydhash was correct earlier) */
+ /* We have a winner! (if bodyhash was correct earlier) */
if (sig->verify_status == PDKIM_VERIFY_NONE)
sig->verify_status = PDKIM_VERIFY_PASS;
else
debug_printf("\n");
}
-
- free(dns_txt_name);
- free(dns_txt_reply);
}
sig = sig->next;
/* -------------------------------------------------------------------------- */
DLLEXPORT pdkim_ctx *
-pdkim_init_verify(int(*dns_txt_callback)(char *, char *))
+pdkim_init_verify(int(*dns_txt_callback)(char *, char *), BOOL dot_stuffing)
{
-pdkim_ctx *ctx = malloc(sizeof(pdkim_ctx));
+pdkim_ctx * ctx;
-if (!ctx)
- return NULL;
+ctx = store_get(sizeof(pdkim_ctx));
memset(ctx, 0, sizeof(pdkim_ctx));
-if (!(ctx->linebuf = malloc(PDKIM_MAX_BODY_LINE_LEN)))
- {
- free(ctx);
- return NULL;
- }
-
-ctx->mode = PDKIM_MODE_VERIFY;
+if (dot_stuffing) ctx->flags = PDKIM_DOT_TERM;
+ctx->linebuf = store_get(PDKIM_MAX_BODY_LINE_LEN);
ctx->dns_txt_callback = dns_txt_callback;
return ctx;
/* -------------------------------------------------------------------------- */
+/*XXX ? needs extension to cover non-RSA algo? Currently the "algo" is actually
+the combo of algo and hash-method */
+
DLLEXPORT pdkim_ctx *
-pdkim_init_sign(char *domain, char *selector, char *rsa_privkey, int algo)
+pdkim_init_sign(char * domain, char * selector, char * rsa_privkey, int algo,
+ BOOL dot_stuffed, int(*dns_txt_callback)(char *, char *),
+ const uschar ** errstr)
{
-pdkim_ctx *ctx;
-pdkim_signature *sig;
+pdkim_ctx * ctx;
+pdkim_signature * sig;
if (!domain || !selector || !rsa_privkey)
return NULL;
-if (!(ctx = malloc(sizeof(pdkim_ctx))))
- return NULL;
+ctx = store_get(sizeof(pdkim_ctx) + PDKIM_MAX_BODY_LINE_LEN + sizeof(pdkim_signature));
memset(ctx, 0, sizeof(pdkim_ctx));
-if (!(ctx->linebuf = malloc(PDKIM_MAX_BODY_LINE_LEN)))
- {
- free(ctx);
- return NULL;
- }
+ctx->flags = dot_stuffed ? PDKIM_MODE_SIGN | PDKIM_DOT_TERM : PDKIM_MODE_SIGN;
+ctx->linebuf = CS (ctx+1);
-if (!(sig = malloc(sizeof(pdkim_signature))))
- {
- free(ctx->linebuf);
- free(ctx);
- return NULL;
- }
+DEBUG(D_acl) ctx->dns_txt_callback = dns_txt_callback;
+
+sig = (pdkim_signature *)(ctx->linebuf + PDKIM_MAX_BODY_LINE_LEN);
memset(sig, 0, sizeof(pdkim_signature));
sig->bodylength = -1;
-
-ctx->mode = PDKIM_MODE_SIGN;
ctx->sig = sig;
-sig->domain = strdup(domain);
-sig->selector = strdup(selector);
-sig->rsa_privkey = strdup(rsa_privkey);
+sig->domain = string_copy(US domain);
+sig->selector = string_copy(US selector);
+sig->rsa_privkey = string_copy(US rsa_privkey);
sig->algo = algo;
-if (!sig->domain || !sig->selector || !sig->rsa_privkey)
- goto BAIL;
+/*XXX extend for sha512 */
+if (!exim_sha_init(&sig->body_hash_ctx,
+ algo == PDKIM_ALGO_RSA_SHA1 ? HASH_SHA1 : HASH_SHA256))
+ {
+ DEBUG(D_acl) debug_printf("PDKIM: hash setup internal error\n");
+ return NULL;
+ }
-exim_sha_init(&sig->body_hash, algo == PDKIM_ALGO_RSA_SHA1);
-return ctx;
+DEBUG(D_acl)
+ {
+ pdkim_signature s = *sig;
+ ev_ctx vctx;
-BAIL:
- pdkim_free_ctx(ctx);
- return NULL;
+ debug_printf("PDKIM (checking verify key)>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
+ if (!pdkim_key_from_dns(ctx, &s, &vctx, errstr))
+ debug_printf("WARNING: bad dkim key in dns\n");
+ debug_printf("PDKIM (finished checking verify key)<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
+ }
+return ctx;
}
unsigned long created,
unsigned long expires)
{
+pdkim_signature * sig = ctx->sig;
+
if (identity)
- if (!(ctx->sig->identity = strdup(identity)))
- return PDKIM_ERR_OOM;
+ sig->identity = string_copy(US identity);
-if (sign_headers)
- if (!(ctx->sig->sign_headers = strdup(sign_headers)))
- return PDKIM_ERR_OOM;
+sig->sign_headers = string_copy(sign_headers
+ ? US sign_headers : US PDKIM_DEFAULT_SIGN_HEADERS);
-ctx->sig->canon_headers = canon_headers;
-ctx->sig->canon_body = canon_body;
-ctx->sig->bodylength = bodylength;
-ctx->sig->created = created;
-ctx->sig->expires = expires;
+sig->canon_headers = canon_headers;
+sig->canon_body = canon_body;
+sig->bodylength = bodylength;
+sig->created = created;
+sig->expires = expires;
return PDKIM_OK;
}
void
pdkim_init(void)
{
-exim_rsa_init();
+exim_dkim_init();
}
projects / exim.git / blobdiff