/*
* PDKIM - a RFC4871 (DKIM) implementation
*
- * Copyright (C) 2017 Exim maintainers
+ * Copyright (C) 1995 - 2018 Exim maintainers
*
* signing/verification interface
*/
#include "../exim.h"
+#include "crypt_ver.h"
+#include "signing.h"
+
+
+#ifdef MACRO_PREDEF
+# include "../macro_predef.h"
+
+void
+features_crypto(void)
+{
+# ifdef SIGN_HAVE_ED25519
+ builtin_macro_create(US"_CRYPTO_SIGN_ED25519");
+# endif
+# ifdef EXIM_HAVE_SHA3
+ builtin_macro_create(US"_CRYPTO_HASH_SHA3");
+# endif
+}
+#else
-#ifndef DISABLE_DKIM /* entire file */
+#ifndef DISABLE_DKIM /* rest of file */
#ifndef SUPPORT_TLS
# error Need SUPPORT_TLS for DKIM
#endif
-#include "crypt_ver.h"
-#include "signing.h"
-
/******************************************************************************/
#ifdef SIGN_GNUTLS
+# define EXIM_GNUTLS_LIBRARY_LOG_LEVEL 3
+
+
+/* Logging function which can be registered with
+ * gnutls_global_set_log_function()
+ * gnutls_global_set_log_level() 0..9
+ */
+#if EXIM_GNUTLS_LIBRARY_LOG_LEVEL >= 0
+static void
+exim_gnutls_logger_cb(int level, const char *message)
+{
+size_t len = strlen(message);
+if (len < 1)
+ {
+ DEBUG(D_tls) debug_printf("GnuTLS<%d> empty debug message\n", level);
+ return;
+ }
+DEBUG(D_tls) debug_printf("GnuTLS<%d>: %s%s", level, message,
+ message[len-1] == '\n' ? "" : "\n");
+}
+#endif
+
+
void
exim_dkim_init(void)
{
+#if EXIM_GNUTLS_LIBRARY_LOG_LEVEL >= 0
+DEBUG(D_tls)
+ {
+ gnutls_global_set_log_function(exim_gnutls_logger_cb);
+ /* arbitrarily chosen level; bump upto 9 for more */
+ gnutls_global_set_log_level(EXIM_GNUTLS_LIBRARY_LOG_LEVEL);
+ }
+#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;
+gnutls_datum_t k = { .data = (void *)privkey_pem, .size = Ustrlen(privkey_pem) };
+gnutls_x509_privkey_t x509_key;
int rc;
-k.data = privkey_pem;
-k.size = strlen(privkey_pem);
-
-if ( (rc = gnutls_x509_privkey_init(&sign_ctx->key)) != GNUTLS_E_SUCCESS
- || (rc = gnutls_x509_privkey_import(sign_ctx->key, &k,
- GNUTLS_X509_FMT_PEM)) != GNUTLS_E_SUCCESS
+if ( (rc = gnutls_x509_privkey_init(&x509_key))
+ || (rc = gnutls_x509_privkey_import(x509_key, &k, GNUTLS_X509_FMT_PEM))
+ || (rc = gnutls_privkey_init(&sign_ctx->key))
+ || (rc = gnutls_privkey_import_x509(sign_ctx->key, x509_key, 0))
)
- return gnutls_strerror(rc);
+ return CUS gnutls_strerror(rc);
+
+switch (rc = gnutls_privkey_get_pk_algorithm(sign_ctx->key, NULL))
+ {
+ case GNUTLS_PK_RSA: sign_ctx->keytype = KEYTYPE_RSA; break;
+#ifdef SIGN_HAVE_ED25519
+ case GNUTLS_PK_EDDSA_ED25519: sign_ctx->keytype = KEYTYPE_ED25519; break;
+#endif
+ default: return rc < 0
+ ? CUS gnutls_strerror(rc)
+ : string_sprintf("Unhandled key type: %d '%s'", rc, gnutls_pk_get_name(rc));
+ }
return NULL;
}
/* allocate mem for signature (when signing) */
-/* sign data (gnutls_only)
-OR
-sign hash.
+/* hash & sign data. No way to do incremental.
Return: NULL for success, or an error string */
const uschar *
exim_dkim_sign(es_ctx * sign_ctx, hashmethod hash, blob * data, blob * sig)
{
+gnutls_datum_t k_data = { .data = data->data, .size = data->len };
gnutls_digest_algorithm_t dig;
-gnutls_datum_t k;
-size_t sigsize = 0;
+gnutls_datum_t k_sig;
int rc;
-const uschar * ret = NULL;
switch (hash)
{
default: return US"nonhandled hash type";
}
-/* Allocate mem for signature */
-k.data = data->data;
-k.size = data->len;
-(void) gnutls_x509_privkey_sign_data(sign_ctx->key, dig,
- 0, &k, NULL, &sigsize);
+if ((rc = gnutls_privkey_sign_data(sign_ctx->key, dig, 0, &k_data, &k_sig)))
+ return CUS gnutls_strerror(rc);
-sig->data = store_get(sigsize);
-sig->len = sigsize;
-
-/* Do signing */
-if ((rc = gnutls_x509_privkey_sign_data(sign_ctx->key, dig,
- 0, &k, sig->data, &sigsize)) != GNUTLS_E_SUCCESS
- )
- ret = gnutls_strerror(rc);
+/* Don't care about deinit for the key; shortlived process */
-gnutls_x509_privkey_deinit(sign_ctx->key);
-return ret;
+sig->data = k_sig.data;
+sig->len = k_sig.size;
+return NULL;
}
-/* import public key (from DER in memory)
+/* import public key (from blob in memory)
Return: NULL for success, or an error string */
const uschar *
-exim_dkim_verify_init(blob * pubkey_der, ev_ctx * verify_ctx)
+exim_dkim_verify_init(blob * pubkey, keyformat fmt, ev_ctx * verify_ctx)
{
gnutls_datum_t k;
int rc;
const uschar * ret = NULL;
gnutls_pubkey_init(&verify_ctx->key);
+k.data = pubkey->data;
+k.size = pubkey->len;
-k.data = pubkey_der->data;
-k.size = pubkey_der->len;
-
-if ((rc = gnutls_pubkey_import(verify_ctx->key, &k, GNUTLS_X509_FMT_DER))
- != GNUTLS_E_SUCCESS)
- ret = gnutls_strerror(rc);
+switch(fmt)
+ {
+ case KEYFMT_DER:
+ if ((rc = gnutls_pubkey_import(verify_ctx->key, &k, GNUTLS_X509_FMT_DER)))
+ ret = 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);
+ break;
+#endif
+ default:
+ ret = US"pubkey format not handled";
+ break;
+ }
return ret;
}
-/* verify signature (of hash) (given pubkey & alleged sig)
+/* verify signature (of hash if RSA sig, of data if EC sig. No way to do incremental)
+(given pubkey & alleged sig)
Return: NULL for success, or an error string */
const uschar *
exim_dkim_verify(ev_ctx * verify_ctx, hashmethod hash, blob * data_hash, blob * sig)
{
-gnutls_sign_algorithm_t algo;
-gnutls_datum_t k, s;
+gnutls_datum_t k = { .data = data_hash->data, .size = data_hash->len };
+gnutls_datum_t s = { .data = sig->data, .size = sig->len };
int rc;
const uschar * ret = NULL;
-/*XXX needs extension for non-rsa */
-switch (hash)
+#ifdef SIGN_HAVE_ED25519
+if (verify_ctx->keytype == KEYTYPE_ED25519)
{
- case HASH_SHA1: algo = GNUTLS_SIGN_RSA_SHA1; break;
- case HASH_SHA2_256: algo = GNUTLS_SIGN_RSA_SHA256; break;
- case HASH_SHA2_512: algo = GNUTLS_SIGN_RSA_SHA512; break;
- default: return US"nonhandled hash type";
+ if ((rc = gnutls_pubkey_verify_data2(verify_ctx->key,
+ GNUTLS_SIGN_EDDSA_ED25519, 0, &k, &s)) < 0)
+ ret = gnutls_strerror(rc);
}
+else
+#endif
+ {
+ gnutls_sign_algorithm_t algo;
+ switch (hash)
+ {
+ case HASH_SHA1: algo = GNUTLS_SIGN_RSA_SHA1; break;
+ case HASH_SHA2_256: algo = GNUTLS_SIGN_RSA_SHA256; break;
+ case HASH_SHA2_512: algo = GNUTLS_SIGN_RSA_SHA512; break;
+ default: return US"nonhandled hash type";
+ }
-k.data = data_hash->data;
-k.size = data_hash->len;
-s.data = sig->data;
-s.size = sig->len;
-if ((rc = gnutls_pubkey_verify_hash2(verify_ctx->key, algo, 0, &k, &s)) < 0)
- ret = gnutls_strerror(rc);
+ if ((rc = gnutls_pubkey_verify_hash2(verify_ctx->key, algo, 0, &k, &s)) < 0)
+ ret = gnutls_strerror(rc);
+ }
gnutls_pubkey_deinit(verify_ctx->key);
return ret;
int taglen;
long tag, len;
-/* debug_printf_indent("as_tag: %02x %02x %02x %02x\n",
- der->data[0], der->data[1], der->data[2], der->data[3]); */
+debug_printf_indent("as_tag: %02x %02x %02x %02x\n",
+ der->data[0], der->data[1], der->data[2], der->data[3]);
if ((rc = asn1_get_tag_der(der->data++, der->len--, &tag_class, &taglen, &tag))
!= ASN1_SUCCESS)
int rc;
gcry_error_t gerr;
+debug_printf_indent("%s\n", __FUNCTION__);
+
/* integer; move past the header */
if ((rc = as_tag(der, 0, ASN1_TAG_INTEGER, &alen)) != ASN1_SUCCESS)
return US asn1_strerror(rc);
/* import private key from PEM string in memory.
+Only handles RSA keys.
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;
int rc;
/*XXX will need extension to _spot_ as well as handle a
-non-RSA key? I think... */
+non-RSA key? I think...
+So... this is not a PrivateKeyInfo - which would have a field
+identifying the keytype - PrivateKeyAlgorithmIdentifier -
+but a plain RSAPrivateKey (wrapped in PEM-headers. Can we
+use those as a type tag? What forms are there? "BEGIN EC PRIVATE KEY" (cf. ec(1ssl))
+
+How does OpenSSL PEM_read_bio_PrivateKey() deal with it?
+gnutls_x509_privkey_import() ?
+*/
/*
* RSAPrivateKey ::= SEQUENCE
* exponent2 INTEGER, -- d mod (q-1)
* coefficient INTEGER, -- (inverse of q) mod p
* otherPrimeInfos OtherPrimeInfos OPTIONAL
+
+ * ECPrivateKey ::= SEQUENCE {
+ * version INTEGER { ecPrivkeyVer1(1) } (ecPrivkeyVer1),
+ * privateKey OCTET STRING,
+ * parameters [0] ECParameters {{ NamedCurve }} OPTIONAL,
+ * publicKey [1] BIT STRING OPTIONAL
+ * }
+ * Hmm, only 1 useful item, and not even an integer? Wonder how we might use it...
+
+- actually, gnutls_x509_privkey_import() appears to require a curve name parameter
+ value for that is an OID? a local-only integer (it's an enum in GnuTLS)?
+
+
+Useful cmds:
+ ssh-keygen -t ecdsa -f foo.privkey
+ ssh-keygen -t ecdsa -b384 -f foo.privkey
+ ssh-keygen -t ecdsa -b521 -f foo.privkey
+ ssh-keygen -t ed25519 -f foo.privkey
+
+ < foo openssl pkcs8 -in /dev/stdin -inform PEM -nocrypt -topk8 -outform DER | od -x
+
+ openssl asn1parse -in foo -inform PEM -dump
+ openssl asn1parse -in foo -inform PEM -dump -stroffset 24 (??)
+(not good for ed25519)
+
*/
-
+
if ( !(s1 = Ustrstr(CS privkey_pem, "-----BEGIN RSA PRIVATE KEY-----"))
|| !(s2 = Ustrstr(CS (s1+=31), "-----END RSA PRIVATE KEY-----" ))
)
debug_printf_indent(" QP: %s\n", s);
}
#endif
+
+sign_ctx->keytype = KEYTYPE_RSA;
return NULL;
asn_err: return US asn1_strerror(rc);
/* allocate mem for signature (when signing) */
-/* sign data (gnutls_only)
-OR
-sign hash.
+/* sign already-hashed data.
Return: NULL for success, or an error string */
}
-/* import public key (from DER in memory)
+/* import public key (from blob in memory)
Return: NULL for success, or an error string */
const uschar *
-exim_dkim_verify_init(blob * pubkey_der, ev_ctx * verify_ctx)
+exim_dkim_verify_init(blob * pubkey, keyformat fmt, ev_ctx * verify_ctx)
{
/*
in code sequence per b81207d2bfa92 rsa_parse_public_key() and asn1_get_mpi()
gcry_error_t gerr;
uschar * stage = US"S1";
+if (fmt != KEYFMT_DER) return US"pubkey format not handled";
+
/*
sequence
sequence
*/
/* sequence; just move past the header */
-if ((rc = as_tag(pubkey_der, ASN1_CLASS_STRUCTURED, ASN1_TAG_SEQUENCE, NULL))
+if ((rc = as_tag(pubkey, ASN1_CLASS_STRUCTURED, ASN1_TAG_SEQUENCE, NULL))
!= ASN1_SUCCESS) goto asn_err;
/* sequence; skip the entire thing */
DEBUG(D_acl) stage = US"S2";
-if ((rc = as_tag(pubkey_der, ASN1_CLASS_STRUCTURED, ASN1_TAG_SEQUENCE, &alen))
+if ((rc = as_tag(pubkey, ASN1_CLASS_STRUCTURED, ASN1_TAG_SEQUENCE, &alen))
!= ASN1_SUCCESS) goto asn_err;
-pubkey_der->data += alen; pubkey_der->len -= alen;
+pubkey->data += alen; pubkey->len -= alen;
/* bitstring: limit range to size of bitstring;
move over header + content wrapper */
DEBUG(D_acl) stage = US"BS";
-if ((rc = as_tag(pubkey_der, 0, ASN1_TAG_BIT_STRING, &alen)) != ASN1_SUCCESS)
+if ((rc = as_tag(pubkey, 0, ASN1_TAG_BIT_STRING, &alen)) != ASN1_SUCCESS)
goto asn_err;
-pubkey_der->len = alen;
-pubkey_der->data++; pubkey_der->len--;
+pubkey->len = alen;
+pubkey->data++; pubkey->len--;
/* sequence; just move past the header */
DEBUG(D_acl) stage = US"S3";
-if ((rc = as_tag(pubkey_der, ASN1_CLASS_STRUCTURED, ASN1_TAG_SEQUENCE, NULL))
+if ((rc = as_tag(pubkey, ASN1_CLASS_STRUCTURED, ASN1_TAG_SEQUENCE, NULL))
!= ASN1_SUCCESS) goto asn_err;
/* read two integers */
DEBUG(D_acl) stage = US"MPI";
-if ( (errstr = as_mpi(pubkey_der, &verify_ctx->n))
- || (errstr = as_mpi(pubkey_der, &verify_ctx->e))
+if ( (errstr = as_mpi(pubkey, &verify_ctx->n))
+ || (errstr = as_mpi(pubkey, &verify_ctx->e))
)
return errstr;
}
-/* verify signature (of hash) (given pubkey & alleged sig)
+/* verify signature (of hash)
+XXX though we appear to be doing a hash, too!
+(given pubkey & alleged sig)
Return: NULL for success, or an error string */
const uschar *
}
-/* accumulate data (gnutls-only) */
+/* 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 g; /*dummy*/
+return string_cat(g, 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);
if (!(sign_ctx->key = PEM_read_bio_PrivateKey(bp, NULL, NULL, NULL)))
return US 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_ED25519
+ ? KEYTYPE_ED25519 : KEYTYPE_RSA;
+#else
+ KEYTYPE_RSA;
+#endif
return NULL;
}
/* allocate mem for signature (when signing) */
-/* sign data (gnutls_only)
-OR
-sign hash.
+/* hash & sign data. Incremental not supported.
Return: NULL for success with the signaature in the sig blob, or an error string */
exim_dkim_sign(es_ctx * sign_ctx, hashmethod hash, blob * data, blob * sig)
{
const EVP_MD * md;
-EVP_PKEY_CTX * ctx;
+EVP_MD_CTX * ctx;
size_t siglen;
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";
}
-if ( (ctx = EVP_PKEY_CTX_new(sign_ctx->key, NULL))
- && EVP_PKEY_sign_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_sign(ctx, NULL, &siglen, data->data, data->len) > 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))
+
+ /* Obtain the signature (slen could change here!) */
+ && EVP_DigestSign(ctx, sig->data, &siglen, data->data, data->len) > 0
)
{
- /* Allocate mem for signature */
- sig->data = store_get(siglen);
-
- if (EVP_PKEY_sign(ctx, sig->data, &siglen, data->data, data->len) > 0)
- {
- EVP_PKEY_CTX_free(ctx);
- sig->len = siglen;
- return NULL;
- }
+ 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
+ && EVP_DigestSignFinal(ctx, NULL, &siglen) > 0
+ && (sig->data = store_get(siglen))
+
+ /* Obtain the signature (slen could change here!) */
+ && EVP_DigestSignFinal(ctx, sig->data, &siglen) > 0
+ )
+ {
+ EVP_MD_CTX_destroy(ctx);
+ sig->len = siglen;
+ return NULL;
+ }
+#endif
-if (ctx) EVP_PKEY_CTX_free(ctx);
+if (ctx) EVP_MD_CTX_destroy(ctx);
return US ERR_error_string(ERR_get_error(), NULL);
}
-/* import public key (from DER in memory)
+/* import public key (from blob in memory)
Return: NULL for success, or an error string */
const uschar *
-exim_dkim_verify_init(blob * pubkey_der, ev_ctx * verify_ctx)
+exim_dkim_verify_init(blob * pubkey, keyformat fmt, ev_ctx * verify_ctx)
{
-const uschar * s = pubkey_der->data;
+const uschar * s = pubkey->data;
+uschar * ret = NULL;
-/*XXX hmm, we never free this */
+switch(fmt)
+ {
+ case KEYFMT_DER:
+ /*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:
+ 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:
+ ret = US"pubkey format not handled";
+ break;
+ }
-if ((verify_ctx->key = d2i_PUBKEY(NULL, &s, pubkey_der->len)))
- return NULL;
-return US ERR_error_string(ERR_get_error(), NULL);
+return ret;
}
-/* verify signature (of hash) (given pubkey & alleged sig)
+/* verify signature (of hash, except Ed25519 where of-data)
+(given pubkey & alleged sig)
Return: NULL for success, or an error string */
const uschar *
-exim_dkim_verify(ev_ctx * verify_ctx, hashmethod hash, blob * data_hash, blob * sig)
+exim_dkim_verify(ev_ctx * verify_ctx, hashmethod hash, blob * data, blob * sig)
{
const EVP_MD * md;
-EVP_PKEY_CTX * ctx;
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";
}
-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_hash->data, data_hash->len) == 1
- )
- { EVP_PKEY_CTX_free(ctx); return NULL; }
+#ifdef SIGN_HAVE_ED25519
+if (!md)
+ {
+ EVP_MD_CTX * ctx;
-if (ctx) EVP_PKEY_CTX_free(ctx);
+ if ( (ctx = EVP_MD_CTX_new())
+ && 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; }
+
+ if (ctx) EVP_MD_CTX_free(ctx);
+ }
+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);
}
/******************************************************************************/
#endif /*DISABLE_DKIM*/
+#endif /*MACRO_PREDEF*/
/* End of File */
git://git.exim.org / exim.git / blobdiff