/*
* PDKIM - a RFC4871 (DKIM) implementation
*
- * Copyright (C) 1995 - 2018 Exim maintainers
+ * Copyright (C) 1995 - 2020 Exim maintainers
*
* signing/verification interface
*/
#ifndef DISABLE_DKIM /* rest of file */
-#ifndef SUPPORT_TLS
-# error Need SUPPORT_TLS for DKIM
+#ifdef DISABLE_TLS
+# error Must no DISABLE_TLS, for DKIM
#endif
Return: NULL for success, or an error string */
const uschar *
-exim_dkim_signing_init(uschar * privkey_pem, es_ctx * sign_ctx)
+exim_dkim_signing_init(const uschar * privkey_pem, es_ctx * sign_ctx)
{
-gnutls_datum_t k = { .data = privkey_pem, .size = Ustrlen(privkey_pem) };
+gnutls_datum_t k = { .data = (void *)privkey_pem, .size = Ustrlen(privkey_pem) };
gnutls_x509_privkey_t x509_key;
+const uschar * where;
int rc;
-if ( (rc = gnutls_x509_privkey_init(&x509_key))
- || (rc = gnutls_x509_privkey_import(x509_key, &k, GNUTLS_X509_FMT_PEM))
+if ( (where = US"internal init", rc = gnutls_x509_privkey_init(&x509_key))
|| (rc = gnutls_privkey_init(&sign_ctx->key))
- || (rc = gnutls_privkey_import_x509(sign_ctx->key, x509_key, 0))
+ || (where = US"privkey PEM-block import",
+ rc = gnutls_x509_privkey_import(x509_key, &k, GNUTLS_X509_FMT_PEM))
+ || (where = US"internal privkey transfer",
+ rc = gnutls_privkey_import_x509(sign_ctx->key, x509_key, 0))
)
- return CUS gnutls_strerror(rc);
+ return string_sprintf("%s: %s", where, gnutls_strerror(rc));
switch (rc = gnutls_privkey_get_pk_algorithm(sign_ctx->key, NULL))
{
Return: NULL for success, or an error string */
const uschar *
-exim_dkim_verify_init(blob * pubkey, keyformat fmt, ev_ctx * verify_ctx)
+exim_dkim_verify_init(blob * pubkey, keyformat fmt, ev_ctx * verify_ctx,
+ unsigned * bits)
{
gnutls_datum_t k;
int rc;
{
case KEYFMT_DER:
if ((rc = gnutls_pubkey_import(verify_ctx->key, &k, GNUTLS_X509_FMT_DER)))
- ret = gnutls_strerror(rc);
+ ret = US gnutls_strerror(rc);
break;
#ifdef SIGN_HAVE_ED25519
case KEYFMT_ED25519_BARE:
if ((rc = gnutls_pubkey_import_ecc_raw(verify_ctx->key,
GNUTLS_ECC_CURVE_ED25519, &k, NULL)))
- ret = gnutls_strerror(rc);
+ ret = US gnutls_strerror(rc);
break;
#endif
default:
ret = US"pubkey format not handled";
break;
}
+if (!ret && bits) gnutls_pubkey_get_pk_algorithm(verify_ctx->key, bits);
return ret;
}
{
if ((rc = gnutls_pubkey_verify_data2(verify_ctx->key,
GNUTLS_SIGN_EDDSA_ED25519, 0, &k, &s)) < 0)
- ret = gnutls_strerror(rc);
+ ret = US gnutls_strerror(rc);
}
else
#endif
}
if ((rc = gnutls_pubkey_verify_hash2(verify_ctx->key, algo, 0, &k, &s)) < 0)
- ret = gnutls_strerror(rc);
+ ret = US gnutls_strerror(rc);
}
gnutls_pubkey_deinit(verify_ctx->key);
Return: NULL for success, or an error string */
const uschar *
-exim_dkim_signing_init(uschar * privkey_pem, es_ctx * sign_ctx)
+exim_dkim_signing_init(const uschar * privkey_pem, es_ctx * sign_ctx)
{
uschar * s1, * s2;
blob der;
*s2 = '\0';
-if ((der.len = b64decode(s1, &der.data)) < 0)
+if ((rc = b64decode(s1, &der.data) < 0))
return US"Bad PEM-DER b64 decode";
+der.len = rc;
/* untangle asn.1 */
}
#define SIGSPACE 128
-sig->data = store_get(SIGSPACE);
+sig->data = store_get(SIGSPACE, FALSE);
if (gcry_mpi_cmp (sign_ctx->p, sign_ctx->q) > 0)
{
Return: NULL for success, or an error string */
const uschar *
-exim_dkim_verify_init(blob * pubkey, keyformat fmt, ev_ctx * verify_ctx)
+exim_dkim_verify_init(blob * pubkey, keyformat fmt, ev_ctx * verify_ctx,
+ unsigned * bits)
{
/*
in code sequence per b81207d2bfa92 rsa_parse_public_key() and asn1_get_mpi()
uschar tag_class;
int taglen;
long alen;
+unsigned nbits;
int rc;
uschar * errstr;
gcry_error_t gerr;
/* read two integers */
DEBUG(D_acl) stage = US"MPI";
-if ( (errstr = as_mpi(pubkey, &verify_ctx->n))
- || (errstr = as_mpi(pubkey, &verify_ctx->e))
- )
- return errstr;
+nbits = pubkey->len;
+if ((errstr = as_mpi(pubkey, &verify_ctx->n))) return errstr;
+nbits = (nbits - pubkey->len) * 8;
+if ((errstr = as_mpi(pubkey, &verify_ctx->e))) return errstr;
#ifdef extreme_debug
DEBUG(D_acl) debug_printf_indent("rsa_verify_init:\n");
}
#endif
+if (bits) *bits = nbits;
return NULL;
asn_err:
}
-/* accumulate data (was gnutls-onl but now needed for OpenSSL non-EC too
+/* accumulate data (was gnutls-only but now needed for OpenSSL non-EC too
because now using hash-and-sign interface) */
gstring *
exim_dkim_data_append(gstring * g, uschar * s)
Return: NULL for success, or an error string */
const uschar *
-exim_dkim_signing_init(uschar * privkey_pem, es_ctx * sign_ctx)
+exim_dkim_signing_init(const uschar * privkey_pem, es_ctx * sign_ctx)
{
-BIO * bp = BIO_new_mem_buf(privkey_pem, -1);
+BIO * bp = BIO_new_mem_buf((void *)privkey_pem, -1);
if (!(sign_ctx->key = PEM_read_bio_PrivateKey(bp, NULL, NULL, NULL)))
- return US ERR_error_string(ERR_get_error(), NULL);
+ return string_sprintf("privkey PEM-block import: %s",
+ ERR_error_string(ERR_get_error(), NULL));
sign_ctx->keytype =
#ifdef SIGN_HAVE_ED25519
- EVP_PKEY_type(EVP_PKEY_id(sign_ctx->key)) == EVP_PKEY_EC
+ EVP_PKEY_type(EVP_PKEY_id(sign_ctx->key)) == EVP_PKEY_ED25519
? KEYTYPE_ED25519 : KEYTYPE_RSA;
#else
KEYTYPE_RSA;
/* allocate mem for signature (when signing) */
-/* hash & sign data. Could be incremental
+/* hash & sign data. Incremental not supported.
Return: NULL for success with the signaature in the sig blob, or an error string */
switch (hash)
{
+ case HASH_NULL: md = NULL; break; /* Ed25519 signing */
case HASH_SHA1: md = EVP_sha1(); break;
case HASH_SHA2_256: md = EVP_sha256(); break;
case HASH_SHA2_512: md = EVP_sha512(); break;
default: return US"nonhandled hash type";
}
-/* Create the Message Digest Context */
-/*XXX renamed to EVP_MD_CTX_new() in 1.1.0 */
-if( (ctx = EVP_MD_CTX_create())
-
-/* Initialise the DigestSign operation */
- && EVP_DigestSignInit(ctx, NULL, md, NULL, sign_ctx->key) > 0
+#ifdef SIGN_HAVE_ED25519
+if ( (ctx = EVP_MD_CTX_new())
+ && EVP_DigestSignInit(ctx, NULL, md, NULL, sign_ctx->key) > 0
+ && EVP_DigestSign(ctx, NULL, &siglen, NULL, 0) > 0
+ && (sig->data = store_get(siglen, FALSE))
- /* Call update with the message */
+ /* Obtain the signature (slen could change here!) */
+ && EVP_DigestSign(ctx, sig->data, &siglen, data->data, data->len) > 0
+ )
+ {
+ EVP_MD_CTX_destroy(ctx);
+ sig->len = siglen;
+ return NULL;
+ }
+#else
+/*XXX renamed to EVP_MD_CTX_new() in 1.1.0 */
+if ( (ctx = EVP_MD_CTX_create())
+ && EVP_DigestSignInit(ctx, NULL, md, NULL, sign_ctx->key) > 0
&& EVP_DigestSignUpdate(ctx, data->data, data->len) > 0
-
- /* Finalise the DigestSign operation */
- /* First call EVP_DigestSignFinal with a NULL sig parameter to obtain the length of the
- * signature. Length is returned in slen */
&& EVP_DigestSignFinal(ctx, NULL, &siglen) > 0
-
- /* Allocate memory for the signature based on size in slen */
- && (sig->data = store_get(siglen))
-
- /* Obtain the signature (slen could change here!) */
+ && (sig->data = store_get(siglen, FALSE))
+
+ /* Obtain the signature (slen could change here!) */
&& EVP_DigestSignFinal(ctx, sig->data, &siglen) > 0
)
{
sig->len = siglen;
return NULL;
}
+#endif
if (ctx) EVP_MD_CTX_destroy(ctx);
return US ERR_error_string(ERR_get_error(), NULL);
Return: NULL for success, or an error string */
const uschar *
-exim_dkim_verify_init(blob * pubkey, keyformat fmt, ev_ctx * verify_ctx)
+exim_dkim_verify_init(blob * pubkey, keyformat fmt, ev_ctx * verify_ctx,
+ unsigned * bits)
{
const uschar * s = pubkey->data;
uschar * ret = NULL;
-if (fmt != KEYFMT_DER) return US"pubkey format not handled";
switch(fmt)
{
case KEYFMT_DER:
- /*XXX ok, this fails for EC:
- error:0609E09C:digital envelope routines:pkey_set_type:unsupported algorithm
- */
-
/*XXX hmm, we never free this */
if (!(verify_ctx->key = d2i_PUBKEY(NULL, &s, pubkey->len)))
ret = US ERR_error_string(ERR_get_error(), NULL);
break;
#ifdef SIGN_HAVE_ED25519
case KEYFMT_ED25519_BARE:
- {
- BIGNUM * x;
- EC_KEY * eck;
- if ( !(x = BN_bin2bn(s, pubkey->len, NULL))
- || !(eck = EC_KEY_new_by_curve_name(NID_ED25519))
- || !EC_KEY_set_public_key_affine_coordinates(eck, x, NULL)
- || !(verify_ctx->key = EVP_PKEY_new())
- || !EVP_PKEY_assign_EC_KEY(verify_ctx->key, eck)
- )
+ if (!(verify_ctx->key = EVP_PKEY_new_raw_public_key(EVP_PKEY_ED25519, NULL,
+ s, pubkey->len)))
ret = US ERR_error_string(ERR_get_error(), NULL);
- }
break;
#endif
default:
break;
}
+if (!ret && bits) *bits = EVP_PKEY_bits(verify_ctx->key);
return ret;
}
-/* verify signature (of hash)
-(pre-EC coding; of data if "notyet" code, The latter could be incremental)
+/* verify signature (of hash, except Ed25519 where of-data)
(given pubkey & alleged sig)
Return: NULL for success, or an error string */
{
const EVP_MD * md;
-/*XXX OpenSSL does not seem to have Ed25519 support yet. Reportedly BoringSSL does,
-but that's a nonstable API and not recommended (by its owner, Google) for external use. */
-
switch (hash)
{
+ case HASH_NULL: md = NULL; break;
case HASH_SHA1: md = EVP_sha1(); break;
case HASH_SHA2_256: md = EVP_sha256(); break;
case HASH_SHA2_512: md = EVP_sha512(); break;
default: return US"nonhandled hash type";
}
-#ifdef notyet_SIGN_HAVE_ED25519
+#ifdef SIGN_HAVE_ED25519
+if (!md)
{
EVP_MD_CTX * ctx;
- /*XXX renamed to EVP_MD_CTX_new() in 1.1.0 */
- if (
- (ctx = EVP_MD_CTX_create())
-
- /* Initialize `key` with a public key */
- && EVP_DigestVerifyInit(ctx, NULL, md, NULL, verify_ctx->key) > 0
-
- /* add data to be hashed (call multiple times if needed) */
-
- && EVP_DigestVerifyUpdate(ctx, data->data, data->len) > 0
-
- /* finish off the hash and check the offered signature */
-
- && EVP_DigestVerifyFinal(ctx, sig->data, sig->len) > 0
- )
+ if ((ctx = EVP_MD_CTX_new()))
{
- EVP_MD_CTX_destroy(ctx); /* renamed to _free in 1.1.0 */
- return NULL;
+ if ( EVP_DigestVerifyInit(ctx, NULL, md, NULL, verify_ctx->key) > 0
+ && EVP_DigestVerify(ctx, sig->data, sig->len, data->data, data->len) > 0
+ )
+ { EVP_MD_CTX_free(ctx); return NULL; }
+ EVP_MD_CTX_free(ctx);
}
-
- if (ctx) EVP_MD_CTX_free(ctx);
- return US ERR_error_string(ERR_get_error(), NULL);
}
-#else
+else
+#endif
{
EVP_PKEY_CTX * ctx;
- if ( (ctx = EVP_PKEY_CTX_new(verify_ctx->key, NULL))
- && EVP_PKEY_verify_init(ctx) > 0
- && EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_PKCS1_PADDING) > 0
- && EVP_PKEY_CTX_set_signature_md(ctx, md) > 0
- && EVP_PKEY_verify(ctx, sig->data, sig->len,
- data->data, data->len) == 1
- )
- { EVP_PKEY_CTX_free(ctx); return NULL; }
-
- if (ctx) EVP_PKEY_CTX_free(ctx);
- return US ERR_error_string(ERR_get_error(), NULL);
+ if ((ctx = EVP_PKEY_CTX_new(verify_ctx->key, NULL)))
+ {
+ if ( EVP_PKEY_verify_init(ctx) > 0
+ && EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_PKCS1_PADDING) > 0
+ && EVP_PKEY_CTX_set_signature_md(ctx, md) > 0
+ && EVP_PKEY_verify(ctx, sig->data, sig->len,
+ data->data, data->len) == 1
+ )
+ { EVP_PKEY_CTX_free(ctx); return NULL; }
+ EVP_PKEY_CTX_free(ctx);
+
+ DEBUG(D_tls)
+ if (Ustrcmp(ERR_reason_error_string(ERR_peek_error()), "wrong signature length") == 0)
+ debug_printf("sig len (from msg hdr): %d, expected (from dns pubkey) %d\n",
+ (int) sig->len, EVP_PKEY_size(verify_ctx->key));
+ }
}
-#endif
+
+return US ERR_error_string(ERR_get_error(), NULL);
}