X-Git-Url: https://git.novaco.in/?a=blobdiff_plain;f=src%2Fecies.cpp;h=dec773f9cecf2d62f65d647d9e0c76b5b2a5fd2c;hb=HEAD;hp=215d390ada5b0fd1fc59e1808e3d3b460b257c79;hpb=b8dd44c350c3fb0b958cea2baba8aab268f44cf2;p=novacoin.git

diff --git a/src/ecies.cpp b/src/ecies.cpp
deleted file mode 100644
index 215d390..0000000
--- a/src/ecies.cpp
+++ /dev/null
@@ -1,568 +0,0 @@
-/**
- * @file /cryptron/ecies.c
- *
- * @brief ECIES encryption/decryption functions.
- *
- * $Author: Ladar Levison $
- * $Website: http://lavabit.com $
- *
- */
-
-#include "ies.h"
-#include <iostream>
-#include <vector>
-#include <openssl/ecdh.h>
-
-#define SET_ERROR(string) \
-    sprintf(error, "%s %s:%d", (string), __FILE__, __LINE__)
-#define SET_OSSL_ERROR(string) \
-    sprintf(error, "%s {error = %s} %s:%d", (string), ERR_error_string(ERR_get_error(), NULL), __FILE__, __LINE__)
-
-/* Copyright (c) 1998-2011 The OpenSSL Project. All rights reserved.
- * Taken from openssl/crypto/ecdh/ech_kdf.c in github:openssl/openssl
- * ffa08b3242e0f10f1fef3c93ef3f0b51de8c27a9 */
-
-/* Key derivation function from X9.62/SECG */
-/* Way more than we will ever need */
-#define ECDH_KDF_MAX (1 << 30)
-int ECDH_KDF_X9_62(unsigned char *out, size_t outlen,
-                   const unsigned char *Z, size_t Zlen,
-                   const unsigned char *sinfo, size_t sinfolen,
-                   const EVP_MD *md)
-{
-    EVP_MD_CTX mctx;
-    int rv = 0;
-    unsigned int i;
-    size_t mdlen;
-    unsigned char ctr[4];
-    if (sinfolen > ECDH_KDF_MAX || outlen > ECDH_KDF_MAX || Zlen > ECDH_KDF_MAX)
-        return 0;
-    mdlen = EVP_MD_size(md);
-    EVP_MD_CTX_init(&mctx);
-    for (i = 1;;i++)
-    {
-        unsigned char mtmp[EVP_MAX_MD_SIZE];
-        EVP_DigestInit_ex(&mctx, md, NULL);
-        ctr[3] = i & 0xFF;
-        ctr[2] = (i >> 8) & 0xFF;
-        ctr[1] = (i >> 16) & 0xFF;
-        ctr[0] = (i >> 24) & 0xFF;
-        if (!EVP_DigestUpdate(&mctx, Z, Zlen))
-            goto err;
-        if (!EVP_DigestUpdate(&mctx, ctr, sizeof(ctr)))
-            goto err;
-        if (!EVP_DigestUpdate(&mctx, sinfo, sinfolen))
-            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:
-    EVP_MD_CTX_cleanup(&mctx);
-    return rv;
-}
-
-static size_t envelope_key_len(const ies_ctx_t *ctx)
-{
-    return EVP_CIPHER_key_length(ctx->cipher) + EVP_MD_size(ctx->md);
-}
-
-static EC_KEY * ecies_key_create(const EC_KEY *user, char *error) {
-
-    const EC_GROUP *group;
-    EC_KEY *key = NULL;
-
-    if (!(key = EC_KEY_new())) {
-        SET_OSSL_ERROR("EC_KEY_new failed");
-        return NULL;
-    }
-
-    if (!(group = EC_KEY_get0_group(user))) {
-        SET_ERROR("The user key does not have group");
-        EC_KEY_free(key);
-        return NULL;
-    }
-
-    if (EC_KEY_set_group(key, group) != 1) {
-        SET_OSSL_ERROR("EC_KEY_set_group failed");
-        EC_KEY_free(key);
-        return NULL;
-    }
-
-    if (EC_KEY_generate_key(key) != 1) {
-        SET_OSSL_ERROR("EC_KEY_generate_key failed");
-        EC_KEY_free(key);
-        return NULL;
-    }
-
-    return key;
-}
-
-static unsigned char *prepare_envelope_key(const ies_ctx_t *ctx, cryptogram_t *cryptogram, char *error)
-{
-
-    const size_t key_buf_len = envelope_key_len(ctx);
-    const size_t ecdh_key_len = (EC_GROUP_get_degree(EC_KEY_get0_group(ctx->user_key)) + 7) / 8;
-    unsigned char *envelope_key = NULL, *ktmp = NULL;
-    EC_KEY *ephemeral = NULL;
-    size_t written_length;
-
-    /* High-level ECDH via EVP does not allow use of arbitrary KDF function.
-     * We should use low-level API for KDF2
-     * c.f. openssl/crypto/ec/ec_pmeth.c */
-    if ((envelope_key = (unsigned char *) OPENSSL_malloc(key_buf_len)) == NULL) {
-        SET_ERROR("Failed to allocate memory for envelope_key");
-        goto err;
-    }
-
-    if (!(ephemeral = ecies_key_create(ctx->user_key, error))) {
-        goto err;
-    }
-
-    /* key agreement and KDF
-     * reference: openssl/crypto/ec/ec_pmeth.c */
-    ktmp = (unsigned char *) OPENSSL_malloc(ecdh_key_len);
-    if (ktmp == NULL) {
-        SET_ERROR("No memory for ECDH temporary key");
-        goto err;
-    }
-
-    if (ECDH_compute_key(ktmp, ecdh_key_len, EC_KEY_get0_public_key(ctx->user_key), ephemeral, NULL)
-        != (int)ecdh_key_len) {
-        SET_OSSL_ERROR("An error occurred while ECDH_compute_key");
-        goto err;
-    }
-
-    /* equals to ISO 18033-2 KDF2 */
-    if (!ECDH_KDF_X9_62(envelope_key, key_buf_len, ktmp, ecdh_key_len, 0, 0, ctx->kdf_md)) {
-        SET_OSSL_ERROR("Failed to stretch with KDF2");
-        goto err;
-    }
-
-    /* Store the public key portion of the ephemeral key. */
-    written_length = EC_POINT_point2oct(
-        EC_KEY_get0_group(ephemeral),
-        EC_KEY_get0_public_key(ephemeral),
-        POINT_CONVERSION_COMPRESSED,
-        cryptogram_key_data(cryptogram),
-        ctx->stored_key_length,
-        NULL);
-    if (written_length == 0) {
-        SET_OSSL_ERROR("Error while recording the public portion of the envelope key");
-        goto err;
-    }
-    if (written_length != ctx->stored_key_length) {
-        SET_ERROR("Written envelope key length does not match with expected");
-        goto err;
-    }
-
-    EC_KEY_free(ephemeral);
-    OPENSSL_cleanse(ktmp, ecdh_key_len);
-    OPENSSL_free(ktmp);
-
-    return envelope_key;
-
-  err:
-    if (ephemeral)
-        EC_KEY_free(ephemeral);
-    if (envelope_key) {
-        OPENSSL_cleanse(envelope_key, key_buf_len);
-        OPENSSL_free(envelope_key);
-    }
-    if (ktmp) {
-        OPENSSL_cleanse(ktmp, ecdh_key_len);
-        OPENSSL_free(ktmp);
-    }
-    return NULL;
-}
-
-static int store_cipher_body(
-    const ies_ctx_t *ctx,
-    const unsigned char *envelope_key,
-    const unsigned char *data,
-    size_t length,
-    cryptogram_t *cryptogram,
-    char *error)
-{
-    int out_len, len_sum = 0;
-    size_t expected_len = cryptogram_body_length(cryptogram);
-    unsigned char iv[EVP_MAX_IV_LENGTH];
-    EVP_CIPHER_CTX cipher;
-    unsigned char *body;
-
-    /* For now we use an empty initialization vector. */
-    memset(iv, 0, EVP_MAX_IV_LENGTH);
-
-    EVP_CIPHER_CTX_init(&cipher);
-    body = cryptogram_body_data(cryptogram);
-
-    if (EVP_EncryptInit_ex(&cipher, ctx->cipher, NULL, envelope_key, iv) != 1
-        || EVP_EncryptUpdate(&cipher, body, &out_len, data, length) != 1) {
-        SET_OSSL_ERROR("Error while trying to secure the data using the symmetric cipher");
-        EVP_CIPHER_CTX_cleanup(&cipher);
-        return 0;
-    }
-
-    if (expected_len < (size_t)out_len) {
-        SET_ERROR("The symmetric cipher overflowed");
-        EVP_CIPHER_CTX_cleanup(&cipher);
-        return 0;
-    }
-
-    body += out_len;
-    len_sum += out_len;
-    if (EVP_EncryptFinal_ex(&cipher, body, &out_len) != 1) {
-        SET_OSSL_ERROR("Error while finalizing the data using the symmetric cipher");
-        EVP_CIPHER_CTX_cleanup(&cipher);
-        cryptogram_free(cryptogram);
-        return 0;
-    }
-
-    EVP_CIPHER_CTX_cleanup(&cipher);
-
-    if (expected_len < (size_t)len_sum) {
-        SET_ERROR("The symmetric cipher overflowed");
-        return 0;
-    }
-
-    return 1;
-}
-
-static int store_mac_tag(const ies_ctx_t *ctx, const unsigned char *envelope_key, cryptogram_t *cryptogram, char *error) {
-    const size_t key_offset = EVP_CIPHER_key_length(ctx->cipher);
-    const size_t key_length = EVP_MD_size(ctx->md);
-    const size_t mac_length = cryptogram_mac_length(cryptogram);
-    unsigned int out_len;
-    HMAC_CTX hmac;
-
-    HMAC_CTX_init(&hmac);
-
-    /* Generate hash tag using encrypted data */
-    if (HMAC_Init_ex(&hmac, envelope_key + key_offset, key_length, ctx->md, NULL) != 1
-        || HMAC_Update(&hmac, cryptogram_body_data(cryptogram), cryptogram_body_length(cryptogram)) != 1
-        || HMAC_Final(&hmac, cryptogram_mac_data(cryptogram), &out_len) != 1) {
-        SET_OSSL_ERROR("Unable to generate tag");
-        HMAC_CTX_cleanup(&hmac);
-        return 0;
-    }
-
-    HMAC_CTX_cleanup(&hmac);
-
-    if (out_len != mac_length) {
-        SET_ERROR("MAC length expectation does not meet");
-        return 0;
-    }
-
-    return 1;
-}
-
-cryptogram_t * ecies_encrypt(const ies_ctx_t *ctx, const unsigned char *data, size_t length, char *error) {
-
-    const size_t block_length = EVP_CIPHER_block_size(ctx->cipher);
-    const size_t mac_length = EVP_MD_size(ctx->md);
-    cryptogram_t *cryptogram = NULL;
-    unsigned char *envelope_key = NULL;
-
-    if (!ctx || !data || !length) {
-        SET_ERROR("Invalid arguments");
-        return NULL;
-    }
-
-    if (block_length == 0 || block_length > EVP_MAX_BLOCK_LENGTH) {
-        SET_ERROR("Derived block size is incorrect");
-        return NULL;
-    }
-
-    cryptogram = cryptogram_alloc(ctx->stored_key_length,
-                                  mac_length,
-                                  length + (length % block_length ? (block_length - (length % block_length)) : 0));
-    if (!cryptogram) {
-        SET_ERROR("Unable to allocate a cryptogram_t buffer to hold the encrypted result.");
-        goto err;
-    }
-
-    if ((envelope_key = prepare_envelope_key(ctx, cryptogram, error)) == NULL) {
-        goto err;
-    }
-
-    if (!store_cipher_body(ctx, envelope_key, data, length, cryptogram, error)) {
-        goto err;
-    }
-
-    if (!store_mac_tag(ctx, envelope_key, cryptogram, error)) {
-        goto err;
-    }
-
-    OPENSSL_cleanse(envelope_key, envelope_key_len(ctx));
-    OPENSSL_free(envelope_key);
-
-    return cryptogram;
-
-  err:
-    if (cryptogram)
-        cryptogram_free(cryptogram);
-    if (envelope_key) {
-        OPENSSL_cleanse(envelope_key, envelope_key_len(ctx));
-        OPENSSL_free(envelope_key);
-    }
-    return NULL;
-}
-
-static EC_KEY *ecies_key_create_public_octets(EC_KEY *user, unsigned char *octets, size_t length, char *error) {
-
-    EC_KEY *key = NULL;
-    EC_POINT *point = NULL;
-    const EC_GROUP *group = NULL;
-
-    if (!(key = EC_KEY_new())) {
-        SET_OSSL_ERROR("Cannot create instance for ephemeral key");
-        return NULL;
-    }
-
-    if (!(group = EC_KEY_get0_group(user))) {
-        SET_ERROR("Cannot get group from user key");
-        EC_KEY_free(key);
-        return NULL;
-    }
-
-    if (EC_KEY_set_group(key, group) != 1) {
-        SET_OSSL_ERROR("EC_KEY_set_group failed");
-        EC_KEY_free(key);
-        return NULL;
-    }
-
-    if (!(point = EC_POINT_new(group))) {
-        SET_OSSL_ERROR("EC_POINT_new failed");
-        EC_KEY_free(key);
-        return NULL;
-    }
-
-    if (EC_POINT_oct2point(group, point, octets, length, NULL) != 1) {
-        SET_OSSL_ERROR("EC_POINT_oct2point failed");
-        EC_KEY_free(key);
-        return NULL;
-    }
-
-    if (EC_KEY_set_public_key(key, point) != 1) {
-        SET_OSSL_ERROR("EC_KEY_set_public_key failed");
-        EC_POINT_free(point);
-        EC_KEY_free(key);
-        return NULL;
-    }
-
-    EC_POINT_free(point);
-
-    if (EC_KEY_check_key(key) != 1) {
-        SET_OSSL_ERROR("EC_KEY_check_key failed");
-        EC_KEY_free(key);
-        return NULL;
-    }
-
-    return key;
-}
-
-unsigned char *restore_envelope_key(const ies_ctx_t *ctx, const cryptogram_t *cryptogram, char *error)
-{
-
-    const size_t key_buf_len = envelope_key_len(ctx);
-    const size_t ecdh_key_len = (EC_GROUP_get_degree(EC_KEY_get0_group(ctx->user_key)) + 7) / 8;
-    EC_KEY *ephemeral = NULL, *user_copy = NULL;
-    unsigned char *envelope_key = NULL, *ktmp = NULL;
-
-    if ((envelope_key = (unsigned char *) OPENSSL_malloc(key_buf_len)) == NULL) {
-        SET_ERROR("Failed to allocate memory for envelope_key");
-        goto err;
-    }
-
-    if (!(user_copy = EC_KEY_new())) {
-        SET_OSSL_ERROR("Failed to create instance for user key copy");
-        goto err;
-    }
-
-    if (!(EC_KEY_copy(user_copy, ctx->user_key))) {
-        SET_OSSL_ERROR("Failed to copy user key");
-        goto err;
-    }
-
-    if (!(ephemeral = ecies_key_create_public_octets(user_copy, cryptogram_key_data(cryptogram), cryptogram_key_length(cryptogram), error))) {
-        goto err;
-    }
-
-    /* key agreement and KDF
-     * reference: openssl/crypto/ec/ec_pmeth.c */
-    ktmp = (unsigned char *) OPENSSL_malloc(ecdh_key_len);
-    if (ktmp == NULL) {
-        SET_ERROR("No memory for ECDH temporary key");
-        goto err;
-    }
-
-    if (ECDH_compute_key(ktmp, ecdh_key_len, EC_KEY_get0_public_key(ephemeral), user_copy, NULL)
-        != (int)ecdh_key_len) {
-        SET_OSSL_ERROR("An error occurred while ECDH_compute_key");
-        goto err;
-    }
-
-    /* equals to ISO 18033-2 KDF2 */
-    if (!ECDH_KDF_X9_62(envelope_key, key_buf_len, ktmp, ecdh_key_len, 0, 0, ctx->kdf_md)) {
-        SET_OSSL_ERROR("Failed to stretch with KDF2");
-        goto err;
-    }
-
-    EC_KEY_free(user_copy);
-    EC_KEY_free(ephemeral);
-    OPENSSL_cleanse(ktmp, ecdh_key_len);
-    OPENSSL_free(ktmp);
-
-    return envelope_key;
-
-  err:
-    if (ephemeral)
-        EC_KEY_free(ephemeral);
-    if (user_copy)
-        EC_KEY_free(user_copy);
-    if (envelope_key) {
-        OPENSSL_cleanse(envelope_key, key_buf_len);
-        OPENSSL_free(envelope_key);
-    }
-    if (ktmp) {
-        OPENSSL_cleanse(ktmp, ecdh_key_len);
-        OPENSSL_free(ktmp);
-    }
-    return NULL;
-}
-
-static int verify_mac(const ies_ctx_t *ctx, const cryptogram_t *cryptogram, const unsigned char * envelope_key, char *error)
-{
-    const size_t key_offset = EVP_CIPHER_key_length(ctx->cipher);
-    const size_t key_length = EVP_MD_size(ctx->md);
-    const size_t mac_length = cryptogram_mac_length(cryptogram);
-    unsigned int out_len;
-    HMAC_CTX hmac;
-    unsigned char md[EVP_MAX_MD_SIZE];
-
-    HMAC_CTX_init(&hmac);
-
-    /* Generate hash tag using encrypted data */
-    if (HMAC_Init_ex(&hmac, envelope_key + key_offset, key_length, ctx->md, NULL) != 1
-        || HMAC_Update(&hmac, cryptogram_body_data(cryptogram), cryptogram_body_length(cryptogram)) != 1
-        || HMAC_Final(&hmac, md, &out_len) != 1) {
-        SET_OSSL_ERROR("Unable to generate tag");
-        HMAC_CTX_cleanup(&hmac);
-        return 0;
-    }
-
-    HMAC_CTX_cleanup(&hmac);
-
-    if (out_len != mac_length) {
-        SET_ERROR("MAC length expectation does not meet");
-        return 0;
-    }
-
-    if (memcmp(md, cryptogram_mac_data(cryptogram), mac_length) != 0) {
-        SET_ERROR("MAC tag verification failed");
-        return 0;
-    }
-
-    return 1;
-}
-
-unsigned char *decrypt_body(const ies_ctx_t *ctx, const cryptogram_t *cryptogram, const unsigned char *envelope_key, size_t *length, char *error)
-{
-    int out_len;
-    size_t output_sum;
-    const size_t body_length = cryptogram_body_length(cryptogram);
-    unsigned char iv[EVP_MAX_IV_LENGTH], *block, *output;
-    EVP_CIPHER_CTX cipher;
-
-    if (!(output = (unsigned char*)malloc(body_length + 1))) {
-        SET_ERROR("Failed to allocate memory for clear text");
-        return NULL;
-    }
-
-    /* For now we use an empty initialization vector */
-    memset(iv, 0, EVP_MAX_IV_LENGTH);
-    memset(output, 0, body_length + 1);
-
-    EVP_CIPHER_CTX_init(&cipher);
-
-    block = output;
-    if (EVP_DecryptInit_ex(&cipher, ctx->cipher, NULL, envelope_key, iv) != 1
-        || EVP_DecryptUpdate(&cipher, block, &out_len, cryptogram_body_data(cryptogram), body_length) != 1) {
-        SET_OSSL_ERROR("Unable to decrypt");
-        EVP_CIPHER_CTX_cleanup(&cipher);
-        free(output);
-        return NULL;
-    }
-    output_sum = out_len;
-
-    block += output_sum;
-    if (EVP_DecryptFinal_ex(&cipher, block, &out_len) != 1) {
-        printf("Unable to decrypt the data using the chosen symmetric cipher. {error = %s}\n", ERR_error_string(ERR_get_error(), NULL));
-        EVP_CIPHER_CTX_cleanup(&cipher);
-        free(output);
-        return NULL;
-    }
-    output_sum += out_len;
-
-    EVP_CIPHER_CTX_cleanup(&cipher);
-
-    *length = output_sum;
-
-    return output;
-}
-
-unsigned char * ecies_decrypt(const ies_ctx_t *ctx, const cryptogram_t *cryptogram, size_t *length, char *error)
-{
-    unsigned char *envelope_key = NULL, *output = NULL;
-
-    if (!ctx || !cryptogram || !length || !error) {
-        SET_ERROR("Invalid argument");
-        goto err;
-    }
-
-    envelope_key = restore_envelope_key(ctx, cryptogram, error);
-    if (envelope_key == NULL) {
-        goto err;
-    }
-
-    if (!verify_mac(ctx, cryptogram, envelope_key, error)) {
-        goto err;
-    }
-
-    if ((output = decrypt_body(ctx, cryptogram, envelope_key, length, error)) == NULL) {
-        goto err;
-    }
-
-  err:
-    OPENSSL_cleanse(envelope_key, envelope_key_len(ctx));
-    OPENSSL_free(envelope_key);
-
-    return output;
-}
-
-ies_ctx_t *create_context(EC_KEY *user_key)
-{
-    ies_ctx_t* ctx = (ies_ctx_t*) malloc(sizeof(ies_ctx_t));
-    ctx->cipher = EVP_aes_128_cbc();
-    ctx->md = EVP_sha1();
-    ctx->kdf_md = EVP_sha1();
-    ctx->stored_key_length = 33;
-    ctx->user_key = user_key;
-
-    return ctx;
-}