* 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/
*
}
}
-const char *
+const uschar *
pdkim_errstr(int status)
{
switch(status)
{
- case PDKIM_OK: return "OK";
- case PDKIM_FAIL: return "FAIL";
- case PDKIM_ERR_RSA_PRIVKEY: return "RSA_PRIVKEY";
- case PDKIM_ERR_RSA_SIGNING: return "RSA SIGNING";
- case PDKIM_ERR_LONG_LINE: return "RSA_LONG_LINE";
- case PDKIM_ERR_BUFFER_TOO_SMALL: return "BUFFER_TOO_SMALL";
- case PDKIM_SIGN_PRIVKEY_WRAP: return "PRIVKEY_WRAP";
- case PDKIM_SIGN_PRIVKEY_B64D: return "PRIVKEY_B64D";
+ 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 "(unknown)";
}
}
pdkim_hexprint(const uschar *data, int len)
{
int i;
-for (i = 0 ; i < len; i++) debug_printf("%02x", data[i]);
+if (data) for (i = 0 ; i < len; i++) debug_printf("%02x", data[i]);
+else debug_printf("<NULL>");
debug_printf("\n");
}
static pdkim_signature *
pdkim_parse_sig_header(pdkim_ctx *ctx, uschar * raw_hdr)
{
-pdkim_signature *sig ;
+pdkim_signature * sig;
uschar *p, *q;
uschar * cur_tag = NULL; int ts = 0, tl = 0;
uschar * cur_val = NULL; int vs = 0, vl = 0;
"PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
}
-exim_sha_init(&sig->body_hash_ctx,
- sig->algo == PDKIM_ALGO_RSA_SHA1 ? HASH_SHA1 : HASH_SHA256);
+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;
}
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);
}
#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[(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->flags & PDKIM_MODE_SIGN)
- {
- pdkim_signature *sig;
-
for (sig = ctx->sig; sig; sig = sig->next) /* Traverse all signatures */
/* 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 */
else
{
+#ifdef notdef
DEBUG(D_acl)
{
debug_printf("PDKIM >> raw hdr: ");
- pdkim_quoteprint(CUS ctx->cur_header, Ustrlen(ctx->cur_header));
+ pdkim_quoteprint(CUS ctx->cur_header, ctx->cur_header_len);
}
+#endif
if (strncasecmp(CCS ctx->cur_header,
DKIM_SIGNATURE_HEADERNAME,
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)))
+ 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");
}
/* all headers are stored for signature verification */
}
BAIL:
-*ctx->cur_header = '\0';
-ctx->cur_header_len = 0; /* leave buffer for reuse */
+ctx->cur_header[ctx->cur_header_len = 0] = '\0'; /* leave buffer for reuse */
return PDKIM_OK;
}
DLLEXPORT int
pdkim_feed(pdkim_ctx *ctx, char *data, int len)
{
-int p;
+int p, rc;
/* Alternate EOD signal, used in non-dotstuffing mode */
if (!data)
ctx->flags |= PDKIM_SEEN_CR;
else if (c == '\n')
{
- int rc;
ctx->flags &= ~PDKIM_SEEN_CR;
if ((rc = pdkim_bodyline_complete(ctx)) != PDKIM_OK)
return rc;
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)
+ if (ctx->flags & PDKIM_SEEN_LF) /* Seen last header line */
{
- int rc = pdkim_header_complete(ctx); /* Seen last header line */
- if (rc != PDKIM_OK) return rc;
+ if ((rc = pdkim_header_complete(ctx)) != PDKIM_OK)
+ return rc;
- ctx->flags = ctx->flags & ~(PDKIM_SEEN_LF|PDKIM_SEEN_CR) | PDKIM_PAST_HDRS;
+ 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");
+ "PDKIM >> Body data for hash, canonicalized >>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
continue;
}
else
- ctx->flags = ctx->flags & ~PDKIM_SEEN_CR | PDKIM_SEEN_LF;
+ ctx->flags = (ctx->flags & ~PDKIM_SEEN_CR) | PDKIM_SEEN_LF;
}
else if (ctx->flags & PDKIM_SEEN_LF)
{
- if (!(c == '\t' || c == ' '))
- {
- int rc = pdkim_header_complete(ctx); /* End of header */
- if (rc != PDKIM_OK) return rc;
- }
+ if (!(c == '\t' || c == ' ')) /* End of header */
+ if ((rc = pdkim_header_complete(ctx)) != PDKIM_OK)
+ return rc;
ctx->flags &= ~PDKIM_SEEN_LF;
}
/* -------------------------------------------------------------------------- */
static pdkim_pubkey *
-pdkim_key_from_dns(pdkim_ctx * ctx, pdkim_signature * sig, ev_ctx * vctx)
+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;
-const uschar * errstr;
/* Fetch public key for signing domain, from DNS */
"PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
/* Import public key */
-if ((errstr = exim_rsa_verify_init(&p->key, vctx)))
+if ((*errstr = exim_rsa_verify_init(&p->key, vctx)))
{
- DEBUG(D_acl) debug_printf("verify_init: %s\n", errstr);
+ 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;
/* -------------------------------------------------------------------------- */
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;
hdata.data = NULL;
hdata.len = 0;
- exim_sha_init(&hhash_ctx, is_sha1 ? HASH_SHA1 : HASH_SHA256);
+ 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 >> Header data for hash, canonicalized, in sequence >>>>>>>>>>>>>>\n");
if (ctx->flags & PDKIM_MODE_SIGN)
{
es_ctx sctx;
- const uschar * errstr;
/* Import private key */
- if ((errstr = exim_rsa_signing_init(US sig->rsa_privkey, &sctx)))
+ if ((*err = exim_rsa_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->sighash)))
+ if ((*err = exim_rsa_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;
}
else
{
ev_ctx vctx;
- const uschar * errstr;
- pdkim_pubkey * p;
/* Make sure we have all required signature tags */
if (!( sig->domain && *sig->domain
goto NEXT_VERIFY;
}
- if (!(sig->pubkey = pdkim_key_from_dns(ctx, sig, &vctx)))
+ if (!(sig->pubkey = pdkim_key_from_dns(ctx, sig, &vctx, err)))
goto NEXT_VERIFY;
/* Check the signature */
- if ((errstr = exim_rsa_verify(&vctx, is_sha1, &hhash, &sig->sighash)))
+ if ((*err = exim_rsa_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;
DLLEXPORT pdkim_ctx *
pdkim_init_sign(char * domain, char * selector, char * rsa_privkey, int algo,
- BOOL dot_stuffed, int(*dns_txt_callback)(char *, char *))
+ BOOL dot_stuffed, int(*dns_txt_callback)(char *, char *),
+ const uschar ** errstr)
{
pdkim_ctx * ctx;
pdkim_signature * sig;
sig->rsa_privkey = string_copy(US rsa_privkey);
sig->algo = algo;
-exim_sha_init(&sig->body_hash_ctx,
- algo == PDKIM_ALGO_RSA_SHA1 ? HASH_SHA1 : HASH_SHA256);
+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;
+ }
+
DEBUG(D_acl)
{
pdkim_signature s = *sig;
ev_ctx vctx;
debug_printf("PDKIM (checking verify key)<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
- if (!pdkim_key_from_dns(ctx, &s, &vctx))
+ 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");
}
git://git.exim.org / exim.git / blobdiff