Add scrypt PBE algorithm code.

This adds support for the ASN.1 structures in draft-josefsson-scrypt-kdf-03
Private keys encrypted by scrypt can now be decrypted transparently as long
as they don't exceed the memory limits.

Reviewed-by: Rich Salz <rsalz@openssl.org>

1 files changed, 332 insertions, 0 deletions

diff --git a/crypto/asn1/p5_scrypt.c b/crypto/asn1/p5_scrypt.c
new file mode 100644
index 0000000000..5c4de797f9
--- /dev/null
+++ b/crypto/asn1/p5_scrypt.c
@@ -0,0 +1,332 @@
+/* p5_scrypt.c */
+/*
+ * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project
+ * 2015.
+ */
+/* ====================================================================
+ * Copyright (c) 2015 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
+ *    licensing@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.
+ * ====================================================================
+ *
+ * This product includes cryptographic software written by Eric Young
+ * (eay@cryptsoft.com).  This product includes software written by Tim
+ * Hudson (tjh@cryptsoft.com).
+ *
+ */
+
+#include <stdio.h>
+#include "internal/cryptlib.h"
+#include <openssl/asn1t.h>
+#include <openssl/err.h>
+#include <openssl/evp.h>
+#include <openssl/x509.h>
+#include <openssl/rand.h>
+
+/* PKCS#5 scrypt password based encryption structures */
+
+typedef struct {
+    ASN1_OCTET_STRING *salt;
+    ASN1_INTEGER *costParameter;
+    ASN1_INTEGER *blockSize;
+    ASN1_INTEGER *parallelizationParameter;
+    ASN1_INTEGER *keyLength;
+} SCRYPT_PARAMS;
+
+ASN1_SEQUENCE(SCRYPT_PARAMS) = {
+        ASN1_SIMPLE(SCRYPT_PARAMS, salt, ASN1_OCTET_STRING),
+        ASN1_SIMPLE(SCRYPT_PARAMS, costParameter, ASN1_INTEGER),
+        ASN1_SIMPLE(SCRYPT_PARAMS, blockSize, ASN1_INTEGER),
+        ASN1_SIMPLE(SCRYPT_PARAMS, parallelizationParameter, ASN1_INTEGER),
+        ASN1_OPT(SCRYPT_PARAMS, keyLength, ASN1_INTEGER),
+} ASN1_SEQUENCE_END(SCRYPT_PARAMS)
+
+DECLARE_ASN1_ALLOC_FUNCTIONS(SCRYPT_PARAMS)
+IMPLEMENT_ASN1_ALLOC_FUNCTIONS(SCRYPT_PARAMS)
+
+static X509_ALGOR *pkcs5_scrypt_set(const unsigned char *salt, size_t saltlen,
+                                    size_t keylen, uint64_t N, uint64_t r,
+                                    uint64_t p);
+
+/*
+ * Return an algorithm identifier for a PKCS#5 v2.0 PBE algorithm using scrypt
+ */
+
+X509_ALGOR *PKCS5_pbe2_set_scrypt(const EVP_CIPHER *cipher,
+                                  const unsigned char *salt, int saltlen,
+                                  unsigned char *aiv, uint64_t N, uint64_t r,
+                                  uint64_t p)
+{
+    X509_ALGOR *scheme = NULL, *kalg = NULL, *ret = NULL;
+    int alg_nid;
+    size_t keylen = 0;
+    EVP_CIPHER_CTX ctx;
+    unsigned char iv[EVP_MAX_IV_LENGTH];
+    PBE2PARAM *pbe2 = NULL;
+    ASN1_OBJECT *obj;
+
+    if (!cipher) {
+        ASN1err(ASN1_F_PKCS5_PBE2_SET_SCRYPT, ERR_R_PASSED_NULL_PARAMETER);
+        goto err;
+    }
+
+    if (EVP_PBE_scrypt(NULL, 0, NULL, 0, N, r, p, 0, NULL, 0) == 0) {
+        ASN1err(ASN1_F_PKCS5_PBE2_SET_SCRYPT,
+                ASN1_R_INVALID_SCRYPT_PARAMETERS);
+        goto err;
+    }
+
+    alg_nid = EVP_CIPHER_type(cipher);
+    if (alg_nid == NID_undef) {
+        ASN1err(ASN1_F_PKCS5_PBE2_SET_SCRYPT,
+                ASN1_R_CIPHER_HAS_NO_OBJECT_IDENTIFIER);
+        goto err;
+    }
+    obj = OBJ_nid2obj(alg_nid);
+    pbe2 = PBE2PARAM_new();
+    if (pbe2 == NULL)
+        goto merr;
+
+    /* Setup the AlgorithmIdentifier for the encryption scheme */
+    scheme = pbe2->encryption;
+
+    scheme->algorithm = obj;
+    scheme->parameter = ASN1_TYPE_new();
+    if (scheme->parameter == NULL)
+        goto merr;
+
+    /* Create random IV */
+    if (EVP_CIPHER_iv_length(cipher)) {
+        if (aiv)
+            memcpy(iv, aiv, EVP_CIPHER_iv_length(cipher));
+        else if (RAND_bytes(iv, EVP_CIPHER_iv_length(cipher)) < 0)
+            goto err;
+    }
+
+    EVP_CIPHER_CTX_init(&ctx);
+
+    /* Dummy cipherinit to just setup the IV */
+    if (EVP_CipherInit_ex(&ctx, cipher, NULL, NULL, iv, 0) == 0)
+        goto err;
+    if (EVP_CIPHER_param_to_asn1(&ctx, scheme->parameter) < 0) {
+        ASN1err(ASN1_F_PKCS5_PBE2_SET_SCRYPT,
+                ASN1_R_ERROR_SETTING_CIPHER_PARAMS);
+        EVP_CIPHER_CTX_cleanup(&ctx);
+        goto err;
+    }
+    EVP_CIPHER_CTX_cleanup(&ctx);
+
+    /* If its RC2 then we'd better setup the key length */
+
+    if (alg_nid == NID_rc2_cbc)
+        keylen = EVP_CIPHER_key_length(cipher);
+
+    /* Setup keyfunc */
+
+    X509_ALGOR_free(pbe2->keyfunc);
+
+    pbe2->keyfunc = pkcs5_scrypt_set(salt, saltlen, keylen, N, r, p);
+
+    if (pbe2->keyfunc == NULL)
+        goto merr;
+
+    /* Now set up top level AlgorithmIdentifier */
+
+    ret = X509_ALGOR_new();
+    if (ret == NULL)
+        goto merr;
+
+    ret->algorithm = OBJ_nid2obj(NID_pbes2);
+
+    /* Encode PBE2PARAM into parameter */
+
+    if (ASN1_TYPE_pack_sequence(ASN1_ITEM_rptr(PBE2PARAM), pbe2,
+                                &ret->parameter) == NULL)
+        goto merr;
+
+    PBE2PARAM_free(pbe2);
+    pbe2 = NULL;
+
+    return ret;
+
+ merr:
+    ASN1err(ASN1_F_PKCS5_PBE2_SET_SCRYPT, ERR_R_MALLOC_FAILURE);
+
+ err:
+    PBE2PARAM_free(pbe2);
+    X509_ALGOR_free(kalg);
+    X509_ALGOR_free(ret);
+
+    return NULL;
+
+}
+
+static X509_ALGOR *pkcs5_scrypt_set(const unsigned char *salt, size_t saltlen,
+                                    size_t keylen, uint64_t N, uint64_t r,
+                                    uint64_t p)
+{
+    X509_ALGOR *keyfunc = NULL;
+    SCRYPT_PARAMS *sparam = NULL;
+
+    sparam = SCRYPT_PARAMS_new();
+    if (sparam == NULL)
+        goto merr;
+
+    if (!saltlen)
+        saltlen = PKCS5_SALT_LEN;
+
+    /* This will either copy salt or grow the buffer */
+    if (ASN1_STRING_set(sparam->salt, salt, saltlen) == 0)
+        goto merr;
+
+    if (salt == NULL && RAND_bytes(sparam->salt->data, saltlen) <= 0)
+        goto err;
+
+    if (ASN1_INTEGER_set_uint64(sparam->costParameter, N) == 0)
+        goto merr;
+
+    if (ASN1_INTEGER_set_uint64(sparam->blockSize, r) == 0)
+        goto merr;
+
+    if (ASN1_INTEGER_set_uint64(sparam->parallelizationParameter, p) == 0)
+        goto merr;
+
+    /* If have a key len set it up */
+
+    if (keylen > 0) {
+        sparam->keyLength = ASN1_INTEGER_new();
+        if (sparam->keyLength == NULL)
+            goto merr;
+        if (ASN1_INTEGER_set_int64(sparam->keyLength, keylen) == 0)
+            goto merr;
+    }
+
+    /* Finally setup the keyfunc structure */
+
+    keyfunc = X509_ALGOR_new();
+    if (!keyfunc)
+        goto merr;
+
+    keyfunc->algorithm = OBJ_nid2obj(NID_id_scrypt);
+
+    /* Encode SCRYPT_PARAMS into parameter of pbe2 */
+
+    if (ASN1_TYPE_pack_sequence(ASN1_ITEM_rptr(SCRYPT_PARAMS), sparam,
+                                &keyfunc->parameter) == NULL)
+        goto merr;
+
+    SCRYPT_PARAMS_free(sparam);
+    return keyfunc;
+
+ merr:
+    ASN1err(ASN1_F_PKCS5_SCRYPT_SET, ERR_R_MALLOC_FAILURE);
+ err:
+    SCRYPT_PARAMS_free(sparam);
+    X509_ALGOR_free(keyfunc);
+    return NULL;
+}
+
+int PKCS5_v2_scrypt_keyivgen(EVP_CIPHER_CTX *ctx, const char *pass,
+                             int passlen, ASN1_TYPE *param,
+                             const EVP_CIPHER *c, const EVP_MD *md, int en_de)
+{
+    unsigned char *salt, key[EVP_MAX_KEY_LENGTH];
+    uint64_t p, r, N;
+    size_t saltlen;
+    size_t keylen = 0;
+    int rv = 0;
+    SCRYPT_PARAMS *sparam = NULL;
+
+    if (EVP_CIPHER_CTX_cipher(ctx) == NULL) {
+        EVPerr(EVP_F_PKCS5_V2_SCRYPT_KEYIVGEN, EVP_R_NO_CIPHER_SET);
+        goto err;
+    }
+
+    /* Decode parameter */
+
+    sparam = ASN1_TYPE_unpack_sequence(ASN1_ITEM_rptr(SCRYPT_PARAMS), param);
+
+    if (sparam == NULL) {
+        EVPerr(EVP_F_PKCS5_V2_SCRYPT_KEYIVGEN, EVP_R_DECODE_ERROR);
+        goto err;
+    }
+
+    keylen = EVP_CIPHER_CTX_key_length(ctx);
+
+    /* Now check the parameters of sparam */
+
+    if (sparam->keyLength) {
+        uint64_t spkeylen;
+        if ((ASN1_INTEGER_get_uint64(&spkeylen, sparam->keyLength) == 0)
+            || (spkeylen != keylen)) {
+            EVPerr(EVP_F_PKCS5_V2_SCRYPT_KEYIVGEN,
+                   EVP_R_UNSUPPORTED_KEYLENGTH);
+            goto err;
+        }
+    }
+    /* Check all parameters fit in uint64_t and are acceptable to scrypt */
+    if (ASN1_INTEGER_get_uint64(&N, sparam->costParameter) == 0
+        || ASN1_INTEGER_get_uint64(&r, sparam->blockSize) == 0
+        || ASN1_INTEGER_get_uint64(&p, sparam->parallelizationParameter) == 0
+        || EVP_PBE_scrypt(NULL, 0, NULL, 0, N, r, p, 0, NULL, 0) == 0) {
+        EVPerr(EVP_F_PKCS5_V2_SCRYPT_KEYIVGEN,
+               EVP_R_ILLEGAL_SCRYPT_PARAMETERS);
+        goto err;
+    }
+
+    /* it seems that its all OK */
+
+    salt = sparam->salt->data;
+    saltlen = sparam->salt->length;
+    if (EVP_PBE_scrypt(pass, passlen, salt, saltlen, N, r, p, 0, key, keylen)
+        == 0)
+        goto err;
+    rv = EVP_CipherInit_ex(ctx, NULL, NULL, key, NULL, en_de);
+ err:
+    if (keylen)
+        OPENSSL_cleanse(key, keylen);
+    SCRYPT_PARAMS_free(sparam);
+    return rv;
+}