Add KDF for DH.
authorDr. Stephen Henson <steve@openssl.org>
Tue, 30 Jul 2013 17:05:08 +0000 (18:05 +0100)
committerDr. Stephen Henson <steve@openssl.org>
Mon, 5 Aug 2013 14:45:01 +0000 (15:45 +0100)
Add X9.42 DH KDF. Move sharedinfo generation code to CMS library as the
same structure is used by DH and ECDH.

Move ASN1_OBJECT typedef to ossl_typ.h so it can be picked up by dh headers
without the need to use ASN1.

crypto/asn1/asn1.h
crypto/cms/cms.h
crypto/cms/cms_asn1.c
crypto/dh/Makefile
crypto/dh/dh.h
crypto/dh/dh_kdf.c [new file with mode: 0644]
crypto/ec/ec_ameth.c
crypto/ossl_typ.h

index accc1e9..8bc24d3 100644 (file)
@@ -208,14 +208,14 @@ typedef struct asn1_const_ctx_st
 #define ASN1_OBJECT_FLAG_CRITICAL       0x02   /* critical x509v3 object id */
 #define ASN1_OBJECT_FLAG_DYNAMIC_STRINGS 0x04  /* internal use */
 #define ASN1_OBJECT_FLAG_DYNAMIC_DATA   0x08   /* internal use */
-typedef struct asn1_object_st
+struct asn1_object_st
        {
        const char *sn,*ln;
        int nid;
        int length;
        const unsigned char *data;      /* data remains const after init */
        int flags;      /* Should we free this one */
-       } ASN1_OBJECT;
+       };
 
 #define ASN1_STRING_FLAG_BITS_LEFT 0x08 /* Set if 0x07 has bits left value */
 /* This indicates that the ASN1_STRING is not a real value but just a place
index f644cbf..8b1d29f 100644 (file)
@@ -364,6 +364,9 @@ EVP_CIPHER_CTX *CMS_RecipientInfo_kari_get0_ctx(CMS_RecipientInfo *ri);
 int CMS_RecipientInfo_kari_decrypt(CMS_ContentInfo *cms, CMS_RecipientInfo *ri,
                                        CMS_RecipientEncryptedKey *rek);
 
+int CMS_SharedInfo_encode(unsigned char **pder, X509_ALGOR *kekalg, 
+                       ASN1_OCTET_STRING *ukm, int keylen);
+
 /* BEGIN ERROR CODES */
 /* The following lines are auto generated by the script mkerr.pl. Any changes
  * made after this point may be overwritten when the script is next run.
index 7d79db2..83ae2cc 100644 (file)
@@ -423,3 +423,46 @@ ASN1_SEQUENCE(CMS_Receipt) = {
   ASN1_SIMPLE(CMS_Receipt, originatorSignatureValue, ASN1_OCTET_STRING)
 } ASN1_SEQUENCE_END(CMS_Receipt)
 
+/* Utilities to encode the CMS_SharedInfo structure used during key
+ * derivation.
+ */
+
+typedef struct {
+       X509_ALGOR *keyInfo;
+       ASN1_OCTET_STRING *entityUInfo;
+       ASN1_OCTET_STRING *suppPubInfo;
+} CMS_SharedInfo;
+
+ASN1_SEQUENCE(CMS_SharedInfo) = {
+  ASN1_SIMPLE(CMS_SharedInfo, keyInfo, X509_ALGOR),
+  ASN1_EXP_OPT(CMS_SharedInfo, entityUInfo, ASN1_OCTET_STRING, 0),
+  ASN1_EXP_OPT(CMS_SharedInfo, suppPubInfo, ASN1_OCTET_STRING, 2),
+} ASN1_SEQUENCE_END(CMS_SharedInfo)
+
+int CMS_SharedInfo_encode(unsigned char **pder, X509_ALGOR *kekalg, 
+                       ASN1_OCTET_STRING *ukm, int keylen)
+       {
+       union {
+               CMS_SharedInfo *pecsi;
+               ASN1_VALUE *a;
+       } intsi = {NULL};
+
+       ASN1_OCTET_STRING oklen;
+       unsigned char kl[4];
+       CMS_SharedInfo ecsi;
+
+       keylen <<= 3;
+       kl[0] = (keylen >> 24) & 0xff;
+       kl[1] = (keylen >> 16) & 0xff;
+       kl[2] = (keylen >> 8) & 0xff;
+       kl[3] = keylen & 0xff;
+       oklen.length = 4;
+       oklen.data = kl;
+       oklen.type = V_ASN1_OCTET_STRING;
+       oklen.flags = 0;
+       ecsi.keyInfo = kekalg;
+       ecsi.entityUInfo = ukm;
+       ecsi.suppPubInfo = &oklen;
+       intsi.pecsi = &ecsi;
+       return ASN1_item_i2d(intsi.a, pder, ASN1_ITEM_rptr(CMS_SharedInfo));
+       }
index 9dd08d6..ca01f37 100644 (file)
@@ -18,9 +18,9 @@ APPS=
 
 LIB=$(TOP)/libcrypto.a
 LIBSRC= dh_asn1.c dh_gen.c dh_key.c dh_lib.c dh_check.c dh_err.c dh_depr.c \
-       dh_ameth.c dh_pmeth.c dh_prn.c dh_rfc5114.c
+       dh_ameth.c dh_pmeth.c dh_prn.c dh_rfc5114.c dh_kdf.c
 LIBOBJ= dh_asn1.o dh_gen.o dh_key.o dh_lib.o dh_check.o dh_err.o dh_depr.o \
-       dh_ameth.o dh_pmeth.o dh_prn.o dh_rfc5114.o
+       dh_ameth.o dh_pmeth.o dh_prn.o dh_rfc5114.o dh_kdf.o
 
 SRC= $(LIBSRC)
 
index 53f9f26..a86c64d 100644 (file)
@@ -239,6 +239,13 @@ DH *DH_get_1024_160(void);
 DH *DH_get_2048_224(void);
 DH *DH_get_2048_256(void);
 
+/* RFC2631 KDF */
+int DH_KDF_X9_42(unsigned char *out, size_t outlen, 
+               const unsigned char *Z, size_t Zlen,
+               ASN1_OBJECT *key_oid,
+               const unsigned char *ukm, size_t ukmlen,
+               const EVP_MD *md);
+
 #define EVP_PKEY_CTX_set_dh_paramgen_prime_len(ctx, len) \
        EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_DH, EVP_PKEY_OP_PARAMGEN, \
                        EVP_PKEY_CTRL_DH_PARAMGEN_PRIME_LEN, len, NULL)
diff --git a/crypto/dh/dh_kdf.c b/crypto/dh/dh_kdf.c
new file mode 100644 (file)
index 0000000..dbdd0b9
--- /dev/null
@@ -0,0 +1,197 @@
+/* crypto/dh/dh_kdf.c */
+/*
+ * Written by Stephen Henson for the OpenSSL project.
+ */
+/* ====================================================================
+ * Copyright (c) 2013 The OpenSSL Project.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer. 
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. All advertising materials mentioning features or use of this
+ *    software must display the following acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission. For written permission, please contact
+ *    openssl-core@openssl.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ *    nor may "OpenSSL" appear in their names without prior written
+ *    permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ *    acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ * ====================================================================
+ */
+
+#include <string.h>
+#include <openssl/dh.h>
+#include <openssl/evp.h>
+#include <openssl/asn1.h>
+#include <openssl/cms.h>
+
+
+/* Key derivation from X9.42/RFC2631 */
+
+#define DH_KDF_MAX     (1L << 30)
+
+/* Skip past an ASN1 structure: for OBJECT skip content octets too */
+
+static int skip_asn1(unsigned char **pp, long *plen, int exptag)
+       {
+       const unsigned char *q = *pp;
+       int i, tag, xclass;
+       long tmplen;
+       i = ASN1_get_object(&q, &tmplen, &tag, &xclass, *plen);
+       if (i & 0x80)
+               return 0;
+       if (tag != exptag || xclass != V_ASN1_UNIVERSAL)
+               return 0;
+       if (tag == V_ASN1_OBJECT)
+               q += tmplen;
+       *plen -= q - *pp;
+       *pp = (unsigned char *)q;
+       return 1;
+       }
+
+/* Encode the DH shared info structure, return an offset to the counter
+ * value so we can update the structure without reencoding it.
+ */
+
+
+static int dh_sharedinfo_encode(unsigned char **pder, unsigned char **pctr,
+                       ASN1_OBJECT *key_oid, size_t outlen,
+                       const unsigned char *ukm, size_t ukmlen)
+       {
+       unsigned char *p;
+       int derlen;
+       long tlen;
+       /* "magic" value to check offset is sane */
+       static unsigned char ctr[4] = {0xF3, 0x17, 0x22, 0x53};
+       X509_ALGOR atmp;
+       ASN1_OCTET_STRING ctr_oct, ukm_oct, *pukm_oct;
+       ASN1_TYPE ctr_atype;
+       if (ukmlen > DH_KDF_MAX || outlen > DH_KDF_MAX)
+               return 0;
+       ctr_oct.data = ctr;
+       ctr_oct.length = 4;
+       ctr_oct.flags = 0;
+       ctr_oct.type = V_ASN1_OCTET_STRING;
+       ctr_atype.type = V_ASN1_OCTET_STRING;
+       ctr_atype.value.octet_string = &ctr_oct;
+       atmp.algorithm = key_oid;
+       atmp.parameter = &ctr_atype;
+       if (ukm)
+               {
+               ukm_oct.type = V_ASN1_OCTET_STRING;
+               ukm_oct.flags = 0;
+               ukm_oct.data = (unsigned char *)ukm;
+               ukm_oct.length = ukmlen;
+               pukm_oct = &ukm_oct;
+               }
+       else
+               pukm_oct = NULL;
+       derlen = CMS_SharedInfo_encode(pder, &atmp, pukm_oct, outlen);
+       if (derlen <= 0)
+               return 0;
+       p = *pder;
+       tlen = derlen;
+       if (!skip_asn1(&p, &tlen, V_ASN1_SEQUENCE))
+               return 0;
+       if (!skip_asn1(&p, &tlen, V_ASN1_SEQUENCE))
+               return 0;
+       if (!skip_asn1(&p, &tlen, V_ASN1_OBJECT))
+               return 0;
+       if (!skip_asn1(&p, &tlen, V_ASN1_OCTET_STRING))
+               return 0;
+       if (memcmp(p, ctr, 4))
+               return 0;
+       *pctr = p;
+       return derlen;
+       }
+
+int DH_KDF_X9_42(unsigned char *out, size_t outlen, 
+               const unsigned char *Z, size_t Zlen,
+               ASN1_OBJECT *key_oid,
+               const unsigned char *ukm, size_t ukmlen,
+               const EVP_MD *md)
+       {
+       EVP_MD_CTX mctx;
+       int rv = 0;
+       unsigned int i;
+       size_t mdlen;
+       unsigned char *der = NULL, *ctr;
+       int derlen;
+       if (Zlen > DH_KDF_MAX)
+               return 0;
+       mdlen = EVP_MD_size(md);
+       EVP_MD_CTX_init(&mctx);
+       derlen = dh_sharedinfo_encode(&der, &ctr, key_oid, outlen,
+                                               ukm, ukmlen);
+       if (derlen == 0)
+               goto err;
+       for (i = 1;;i++)
+               {
+               unsigned char mtmp[EVP_MAX_MD_SIZE];
+               EVP_DigestInit_ex(&mctx, md, NULL);
+               if (!EVP_DigestUpdate(&mctx, Z, Zlen))
+                       goto err;
+               ctr[3] = i & 0xFF;
+               ctr[2] = (i >> 8) & 0xFF;
+               ctr[1] = (i >> 16) & 0xFF;
+               ctr[0] = (i >> 24) & 0xFF;
+               if (!EVP_DigestUpdate(&mctx, der, derlen))
+                       goto err;
+               if (outlen >= mdlen)
+                       {
+                       if (!EVP_DigestFinal(&mctx, out, NULL))
+                               goto err;
+                       outlen -= mdlen;
+                       if (outlen == 0)
+                               break;
+                       out += mdlen;
+                       }
+               else
+                       {
+                       if (!EVP_DigestFinal(&mctx, mtmp, NULL))
+                               goto err;
+                       memcpy(out, mtmp, outlen);
+                       OPENSSL_cleanse(mtmp, mdlen);
+                       break;
+                       }
+               }
+       rv = 1;
+       err:
+       if (der)
+               OPENSSL_free(der);
+       EVP_MD_CTX_cleanup(&mctx);
+       return rv;
+       }
+
index d757fd6..f024f90 100644 (file)
@@ -764,63 +764,6 @@ static int ecdh_cms_set_kdf_param(EVP_PKEY_CTX *pctx, int eckdf_nid)
        return 1;
        }
 
-/* Utilities to encode the ECC_CMS_SharedInfo structure used during key
- * derivation.
- */
-
-typedef struct {
-       X509_ALGOR *keyInfo;
-       ASN1_OCTET_STRING *entityUInfo;
-       ASN1_OCTET_STRING *suppPubInfo;
-} ECC_CMS_SharedInfo;
-
-ASN1_SEQUENCE(ECC_CMS_SharedInfo) = {
-  ASN1_SIMPLE(ECC_CMS_SharedInfo, keyInfo, X509_ALGOR),
-  ASN1_EXP_OPT(ECC_CMS_SharedInfo, entityUInfo, ASN1_OCTET_STRING, 0),
-  ASN1_EXP_OPT(ECC_CMS_SharedInfo, suppPubInfo, ASN1_OCTET_STRING, 2),
-} ASN1_SEQUENCE_END(ECC_CMS_SharedInfo)
-
-static int ecdh_cms_set_ukm(EVP_PKEY_CTX *pctx, 
-                                       X509_ALGOR *kekalg, 
-                                       ASN1_OCTET_STRING *ukm,
-                                       int keylen)
-       {
-       union {
-               ECC_CMS_SharedInfo *pecsi;
-               ASN1_VALUE *a;
-       } intsi = {NULL};
-
-       unsigned char *der = NULL;
-       int plen;
-       ASN1_OCTET_STRING oklen;
-       unsigned char kl[4];
-       ECC_CMS_SharedInfo ecsi;
-
-       keylen <<= 3;
-       kl[0] = (keylen >> 24) & 0xff;
-       kl[1] = (keylen >> 16) & 0xff;
-       kl[2] = (keylen >> 8) & 0xff;
-       kl[3] = keylen & 0xff;
-       oklen.length = 4;
-       oklen.data = kl;
-       oklen.type = V_ASN1_OCTET_STRING;
-       oklen.flags = 0;
-       ecsi.keyInfo = kekalg;
-       ecsi.entityUInfo = ukm;
-       ecsi.suppPubInfo = &oklen;
-       intsi.pecsi = &ecsi;
-       plen = ASN1_item_i2d(intsi.a, &der, ASN1_ITEM_rptr(ECC_CMS_SharedInfo));
-       if (!der || !plen)
-               goto err;
-       if (EVP_PKEY_CTX_set0_ecdh_kdf_ukm(pctx, der, plen) <= 0)
-               goto err;
-       return 1;
-       err:
-       if (der)
-               OPENSSL_free(der);
-       return 0;
-       }
-
 static int ecdh_cms_set_shared_info(EVP_PKEY_CTX *pctx, CMS_RecipientInfo *ri)
        {
        int rv = 0;
@@ -828,6 +771,7 @@ static int ecdh_cms_set_shared_info(EVP_PKEY_CTX *pctx, CMS_RecipientInfo *ri)
        X509_ALGOR *alg, *kekalg = NULL;
        ASN1_OCTET_STRING *ukm;
        const unsigned char *p;
+       unsigned char *der = NULL;
        int plen, keylen;
        const EVP_CIPHER *kekcipher;
        EVP_CIPHER_CTX *kekctx;
@@ -864,13 +808,21 @@ static int ecdh_cms_set_shared_info(EVP_PKEY_CTX *pctx, CMS_RecipientInfo *ri)
        if (EVP_PKEY_CTX_set_ecdh_kdf_outlen(pctx, keylen) <= 0)
                goto err;
 
-       if (!ecdh_cms_set_ukm(pctx, kekalg, ukm, keylen))
+       plen = CMS_SharedInfo_encode(&der, kekalg, ukm, keylen);
+
+       if (!plen)
                goto err;
 
+       if (EVP_PKEY_CTX_set0_ecdh_kdf_ukm(pctx, der, plen) <= 0)
+               goto err;
+       der = NULL;
+
        rv = 1;
        err:
        if (kekalg)
                X509_ALGOR_free(kekalg);
+       if (der)
+               OPENSSL_free(der);
        return rv;
        }
 
@@ -1019,13 +971,19 @@ static int ecdh_cms_encrypt(CMS_RecipientInfo *ri)
 
        if (EVP_PKEY_CTX_set_ecdh_kdf_outlen(pctx, keylen) <= 0)
                goto err;
-       if (!ecdh_cms_set_ukm(pctx, wrap_alg, ukm, keylen))
+
+       penclen = CMS_SharedInfo_encode(&penc, wrap_alg, ukm, keylen);
+
+       if (!penclen)
                goto err;
 
+       if (EVP_PKEY_CTX_set0_ecdh_kdf_ukm(pctx, penc, penclen) <= 0)
+               goto err;
+       penc = NULL;
+
        /* Now need to wrap encoding of wrap AlgorithmIdentifier into
         * parameter of another AlgorithmIdentifier.
         */
-       penc = NULL;
        penclen = i2d_X509_ALGOR(wrap_alg, &penc);
        if (!penc || !penclen)
                goto err;
index 9e6995d..e78a034 100644 (file)
@@ -96,6 +96,8 @@ typedef int ASN1_BOOLEAN;
 typedef int ASN1_NULL;
 #endif
 
+typedef struct asn1_object_st ASN1_OBJECT;
+
 typedef struct ASN1_ITEM_st ASN1_ITEM;
 typedef struct asn1_pctx_st ASN1_PCTX;
 typedef struct asn1_sctx_st ASN1_SCTX;