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-rw-r--r--xlators/encryption/crypt/src/keys.c302
1 files changed, 302 insertions, 0 deletions
diff --git a/xlators/encryption/crypt/src/keys.c b/xlators/encryption/crypt/src/keys.c
new file mode 100644
index 00000000000..4a1d3bb5a09
--- /dev/null
+++ b/xlators/encryption/crypt/src/keys.c
@@ -0,0 +1,302 @@
+/*
+ Copyright (c) 2008-2013 Red Hat, Inc. <http://www.redhat.com>
+ This file is part of GlusterFS.
+
+ This file is licensed to you under your choice of the GNU Lesser
+ General Public License, version 3 or any later version (LGPLv3 or
+ later), or the GNU General Public License, version 2 (GPLv2), in all
+ cases as published by the Free Software Foundation.
+*/
+
+#ifndef _CONFIG_H
+#define _CONFIG_H
+#include "config.h"
+#endif
+
+#include "defaults.h"
+#include "crypt-common.h"
+#include "crypt.h"
+
+/* Key hierarchy
+
+ +----------------+
+ | MASTER_VOL_KEY |
+ +-------+--------+
+ |
+ |
+ +----------------+----------------+
+ | | |
+ | | |
+ +-------+------+ +-------+-------+ +------+--------+
+ | NMTD_VOL_KEY | | EMTD_FILE_KEY | | DATA_FILE_KEY |
+ +-------+------+ +---------------+ +---------------+
+ |
+ |
+ +-------+-------+
+ | NMTD_LINK_KEY |
+ +---------------+
+
+ */
+
+#if DEBUG_CRYPT
+static void check_prf_iters(uint32_t num_iters)
+{
+ if (num_iters == 0)
+ gf_log ("crypt", GF_LOG_DEBUG,
+ "bad number of prf iterations : %d", num_iters);
+}
+#else
+#define check_prf_iters(num_iters) noop
+#endif /* DEBUG_CRYPT */
+
+unsigned char crypt_fake_oid[16] =
+ {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
+
+/*
+ * derive key in the counter mode using
+ * sha256-based HMAC as PRF, see
+ * NIST Special Publication 800-108, 5.1)
+ */
+
+#define PRF_OUTPUT_SIZE SHA256_DIGEST_LENGTH
+
+static int32_t kderive_init(struct kderive_context *ctx,
+ const unsigned char *pkey, /* parent key */
+ uint32_t pkey_size, /* parent key size */
+ const unsigned char *idctx, /* id-context */
+ uint32_t idctx_size,
+ crypt_key_type type /* type of child key */)
+{
+ unsigned char *pos;
+ uint32_t llen = strlen(crypt_keys[type].label);
+ /*
+ * Compoud the fixed input data for KDF:
+ * [i]_2 || Label || 0x00 || Id-Context || [L]_2),
+ * NIST SP 800-108, 5.1
+ */
+ ctx->fid_len =
+ sizeof(uint32_t) +
+ llen +
+ 1 +
+ idctx_size +
+ sizeof(uint32_t);
+
+ ctx->fid = GF_CALLOC(ctx->fid_len, 1, gf_crypt_mt_key);
+ if (!ctx->fid)
+ return ENOMEM;
+ ctx->out_len = round_up(crypt_keys[type].len >> 3,
+ PRF_OUTPUT_SIZE);
+ ctx->out = GF_CALLOC(ctx->out_len, 1, gf_crypt_mt_key);
+ if (!ctx->out) {
+ GF_FREE(ctx->fid);
+ return ENOMEM;
+ }
+ ctx->pkey = pkey;
+ ctx->pkey_len = pkey_size;
+ ctx->ckey_len = crypt_keys[type].len;
+
+ pos = ctx->fid;
+
+ /* counter will be set up in kderive_rfn() */
+ pos += sizeof(uint32_t);
+
+ memcpy(pos, crypt_keys[type].label, llen);
+ pos += llen;
+
+ /* set up zero octet */
+ *pos = 0;
+ pos += 1;
+
+ memcpy(pos, idctx, idctx_size);
+ pos += idctx_size;
+
+ *((uint32_t *)pos) = htobe32(ctx->ckey_len);
+
+ return 0;
+}
+
+static void kderive_update(struct kderive_context *ctx)
+{
+ uint32_t i;
+ HMAC_CTX hctx;
+ unsigned char *pos = ctx->out;
+ uint32_t *p_iter = (uint32_t *)ctx->fid;
+ uint32_t num_iters = ctx->out_len / PRF_OUTPUT_SIZE;
+
+ check_prf_iters(num_iters);
+
+ HMAC_CTX_init(&hctx);
+ for (i = 0; i < num_iters; i++) {
+ /*
+ * update the iteration number in the fid
+ */
+ *p_iter = htobe32(i);
+ HMAC_Init_ex(&hctx,
+ ctx->pkey, ctx->pkey_len >> 3,
+ EVP_sha256(),
+ NULL);
+ HMAC_Update(&hctx, ctx->fid, ctx->fid_len);
+ HMAC_Final(&hctx, pos, NULL);
+
+ pos += PRF_OUTPUT_SIZE;
+ }
+ HMAC_CTX_cleanup(&hctx);
+}
+
+static void kderive_final(struct kderive_context *ctx, unsigned char *child)
+{
+ memcpy(child, ctx->out, ctx->ckey_len >> 3);
+ GF_FREE(ctx->fid);
+ GF_FREE(ctx->out);
+ memset(ctx, 0, sizeof(*ctx));
+}
+
+/*
+ * derive per-volume key for object ids aithentication
+ */
+int32_t get_nmtd_vol_key(struct master_cipher_info *master)
+{
+ int32_t ret;
+ struct kderive_context ctx;
+
+ ret = kderive_init(&ctx,
+ master->m_key,
+ master_key_size(),
+ crypt_fake_oid, sizeof(uuid_t), NMTD_VOL_KEY);
+ if (ret)
+ return ret;
+ kderive_update(&ctx);
+ kderive_final(&ctx, master->m_nmtd_key);
+ return 0;
+}
+
+/*
+ * derive per-link key for aithentication of non-encrypted
+ * meta-data (nmtd)
+ */
+int32_t get_nmtd_link_key(loc_t *loc,
+ struct master_cipher_info *master,
+ unsigned char *result)
+{
+ int32_t ret;
+ struct kderive_context ctx;
+
+ ret = kderive_init(&ctx,
+ master->m_nmtd_key,
+ nmtd_vol_key_size(),
+ (const unsigned char *)loc->path,
+ strlen(loc->path), NMTD_LINK_KEY);
+ if (ret)
+ return ret;
+ kderive_update(&ctx);
+ kderive_final(&ctx, result);
+ return 0;
+}
+
+/*
+ * derive per-file key for encryption and authentication
+ * of encrypted part of metadata (emtd)
+ */
+int32_t get_emtd_file_key(struct crypt_inode_info *info,
+ struct master_cipher_info *master,
+ unsigned char *result)
+{
+ int32_t ret;
+ struct kderive_context ctx;
+
+ ret = kderive_init(&ctx,
+ master->m_key,
+ master_key_size(),
+ info->oid, sizeof(uuid_t), EMTD_FILE_KEY);
+ if (ret)
+ return ret;
+ kderive_update(&ctx);
+ kderive_final(&ctx, result);
+ return 0;
+}
+
+static int32_t data_key_type_by_size(uint32_t keysize, crypt_key_type *type)
+{
+ int32_t ret = 0;
+ switch (keysize) {
+ case 256:
+ *type = DATA_FILE_KEY_256;
+ break;
+ case 512:
+ *type = DATA_FILE_KEY_512;
+ break;
+ default:
+ gf_log("crypt", GF_LOG_ERROR, "Unsupported data key size %d",
+ keysize);
+ ret = ENOTSUP;
+ break;
+ }
+ return ret;
+}
+
+/*
+ * derive per-file key for data encryption
+ */
+int32_t get_data_file_key(struct crypt_inode_info *info,
+ struct master_cipher_info *master,
+ uint32_t keysize,
+ unsigned char *key)
+{
+ int32_t ret;
+ struct kderive_context ctx;
+ crypt_key_type type;
+
+ ret = data_key_type_by_size(keysize, &type);
+ if (ret)
+ return ret;
+ ret = kderive_init(&ctx,
+ master->m_key,
+ master_key_size(),
+ info->oid, sizeof(uuid_t), type);
+ if (ret)
+ return ret;
+ kderive_update(&ctx);
+ kderive_final(&ctx, key);
+ return 0;
+}
+
+/*
+ * NOTE: Don't change existing keys: it will break compatibility;
+ */
+struct crypt_key crypt_keys[LAST_KEY_TYPE] = {
+ [MASTER_VOL_KEY] =
+ { .len = MASTER_VOL_KEY_SIZE << 3,
+ .label = "volume-master",
+ },
+ [NMTD_VOL_KEY] =
+ { .len = NMTD_VOL_KEY_SIZE << 3,
+ .label = "volume-nmtd-key-generation"
+ },
+ [NMTD_LINK_KEY] =
+ { .len = 128,
+ .label = "link-nmtd-authentication"
+ },
+ [EMTD_FILE_KEY] =
+ { .len = 128,
+ .label = "file-emtd-encryption-and-auth"
+ },
+ [DATA_FILE_KEY_256] =
+ { .len = 256,
+ .label = "file-data-encryption-256"
+ },
+ [DATA_FILE_KEY_512] =
+ { .len = 512,
+ .label = "file-data-encryption-512"
+ }
+};
+
+/*
+ Local variables:
+ c-indentation-style: "K&R"
+ mode-name: "LC"
+ c-basic-offset: 8
+ tab-width: 8
+ fill-column: 80
+ scroll-step: 1
+ End:
+*/
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