diff options
Diffstat (limited to 'net/ceph/crypto.c')
| -rw-r--r-- | net/ceph/crypto.c | 583 |
1 files changed, 583 insertions, 0 deletions
diff --git a/net/ceph/crypto.c b/net/ceph/crypto.c new file mode 100644 index 000000000..790fe89d9 --- /dev/null +++ b/net/ceph/crypto.c @@ -0,0 +1,583 @@ + +#include <linux/ceph/ceph_debug.h> + +#include <linux/err.h> +#include <linux/scatterlist.h> +#include <linux/slab.h> +#include <crypto/hash.h> +#include <linux/key-type.h> + +#include <keys/ceph-type.h> +#include <keys/user-type.h> +#include <linux/ceph/decode.h> +#include "crypto.h" + +int ceph_crypto_key_clone(struct ceph_crypto_key *dst, + const struct ceph_crypto_key *src) +{ + memcpy(dst, src, sizeof(struct ceph_crypto_key)); + dst->key = kmemdup(src->key, src->len, GFP_NOFS); + if (!dst->key) + return -ENOMEM; + return 0; +} + +int ceph_crypto_key_encode(struct ceph_crypto_key *key, void **p, void *end) +{ + if (*p + sizeof(u16) + sizeof(key->created) + + sizeof(u16) + key->len > end) + return -ERANGE; + ceph_encode_16(p, key->type); + ceph_encode_copy(p, &key->created, sizeof(key->created)); + ceph_encode_16(p, key->len); + ceph_encode_copy(p, key->key, key->len); + return 0; +} + +int ceph_crypto_key_decode(struct ceph_crypto_key *key, void **p, void *end) +{ + ceph_decode_need(p, end, 2*sizeof(u16) + sizeof(key->created), bad); + key->type = ceph_decode_16(p); + ceph_decode_copy(p, &key->created, sizeof(key->created)); + key->len = ceph_decode_16(p); + ceph_decode_need(p, end, key->len, bad); + key->key = kmalloc(key->len, GFP_NOFS); + if (!key->key) + return -ENOMEM; + ceph_decode_copy(p, key->key, key->len); + return 0; + +bad: + dout("failed to decode crypto key\n"); + return -EINVAL; +} + +int ceph_crypto_key_unarmor(struct ceph_crypto_key *key, const char *inkey) +{ + int inlen = strlen(inkey); + int blen = inlen * 3 / 4; + void *buf, *p; + int ret; + + dout("crypto_key_unarmor %s\n", inkey); + buf = kmalloc(blen, GFP_NOFS); + if (!buf) + return -ENOMEM; + blen = ceph_unarmor(buf, inkey, inkey+inlen); + if (blen < 0) { + kfree(buf); + return blen; + } + + p = buf; + ret = ceph_crypto_key_decode(key, &p, p + blen); + kfree(buf); + if (ret) + return ret; + dout("crypto_key_unarmor key %p type %d len %d\n", key, + key->type, key->len); + return 0; +} + + + +#define AES_KEY_SIZE 16 + +static struct crypto_blkcipher *ceph_crypto_alloc_cipher(void) +{ + return crypto_alloc_blkcipher("cbc(aes)", 0, CRYPTO_ALG_ASYNC); +} + +static const u8 *aes_iv = (u8 *)CEPH_AES_IV; + +/* + * Should be used for buffers allocated with ceph_kvmalloc(). + * Currently these are encrypt out-buffer (ceph_buffer) and decrypt + * in-buffer (msg front). + * + * Dispose of @sgt with teardown_sgtable(). + * + * @prealloc_sg is to avoid memory allocation inside sg_alloc_table() + * in cases where a single sg is sufficient. No attempt to reduce the + * number of sgs by squeezing physically contiguous pages together is + * made though, for simplicity. + */ +static int setup_sgtable(struct sg_table *sgt, struct scatterlist *prealloc_sg, + const void *buf, unsigned int buf_len) +{ + struct scatterlist *sg; + const bool is_vmalloc = is_vmalloc_addr(buf); + unsigned int off = offset_in_page(buf); + unsigned int chunk_cnt = 1; + unsigned int chunk_len = PAGE_ALIGN(off + buf_len); + int i; + int ret; + + if (buf_len == 0) { + memset(sgt, 0, sizeof(*sgt)); + return -EINVAL; + } + + if (is_vmalloc) { + chunk_cnt = chunk_len >> PAGE_SHIFT; + chunk_len = PAGE_SIZE; + } + + if (chunk_cnt > 1) { + ret = sg_alloc_table(sgt, chunk_cnt, GFP_NOFS); + if (ret) + return ret; + } else { + WARN_ON(chunk_cnt != 1); + sg_init_table(prealloc_sg, 1); + sgt->sgl = prealloc_sg; + sgt->nents = sgt->orig_nents = 1; + } + + for_each_sg(sgt->sgl, sg, sgt->orig_nents, i) { + struct page *page; + unsigned int len = min(chunk_len - off, buf_len); + + if (is_vmalloc) + page = vmalloc_to_page(buf); + else + page = virt_to_page(buf); + + sg_set_page(sg, page, len, off); + + off = 0; + buf += len; + buf_len -= len; + } + WARN_ON(buf_len != 0); + + return 0; +} + +static void teardown_sgtable(struct sg_table *sgt) +{ + if (sgt->orig_nents > 1) + sg_free_table(sgt); +} + +static int ceph_aes_encrypt(const void *key, int key_len, + void *dst, size_t *dst_len, + const void *src, size_t src_len) +{ + struct scatterlist sg_in[2], prealloc_sg; + struct sg_table sg_out; + struct crypto_blkcipher *tfm = ceph_crypto_alloc_cipher(); + struct blkcipher_desc desc = { .tfm = tfm, .flags = 0 }; + int ret; + void *iv; + int ivsize; + size_t zero_padding = (0x10 - (src_len & 0x0f)); + char pad[16]; + + if (IS_ERR(tfm)) + return PTR_ERR(tfm); + + memset(pad, zero_padding, zero_padding); + + *dst_len = src_len + zero_padding; + + sg_init_table(sg_in, 2); + sg_set_buf(&sg_in[0], src, src_len); + sg_set_buf(&sg_in[1], pad, zero_padding); + ret = setup_sgtable(&sg_out, &prealloc_sg, dst, *dst_len); + if (ret) + goto out_tfm; + + crypto_blkcipher_setkey((void *)tfm, key, key_len); + iv = crypto_blkcipher_crt(tfm)->iv; + ivsize = crypto_blkcipher_ivsize(tfm); + memcpy(iv, aes_iv, ivsize); + + /* + print_hex_dump(KERN_ERR, "enc key: ", DUMP_PREFIX_NONE, 16, 1, + key, key_len, 1); + print_hex_dump(KERN_ERR, "enc src: ", DUMP_PREFIX_NONE, 16, 1, + src, src_len, 1); + print_hex_dump(KERN_ERR, "enc pad: ", DUMP_PREFIX_NONE, 16, 1, + pad, zero_padding, 1); + */ + ret = crypto_blkcipher_encrypt(&desc, sg_out.sgl, sg_in, + src_len + zero_padding); + if (ret < 0) { + pr_err("ceph_aes_crypt failed %d\n", ret); + goto out_sg; + } + /* + print_hex_dump(KERN_ERR, "enc out: ", DUMP_PREFIX_NONE, 16, 1, + dst, *dst_len, 1); + */ + +out_sg: + teardown_sgtable(&sg_out); +out_tfm: + crypto_free_blkcipher(tfm); + return ret; +} + +static int ceph_aes_encrypt2(const void *key, int key_len, void *dst, + size_t *dst_len, + const void *src1, size_t src1_len, + const void *src2, size_t src2_len) +{ + struct scatterlist sg_in[3], prealloc_sg; + struct sg_table sg_out; + struct crypto_blkcipher *tfm = ceph_crypto_alloc_cipher(); + struct blkcipher_desc desc = { .tfm = tfm, .flags = 0 }; + int ret; + void *iv; + int ivsize; + size_t zero_padding = (0x10 - ((src1_len + src2_len) & 0x0f)); + char pad[16]; + + if (IS_ERR(tfm)) + return PTR_ERR(tfm); + + memset(pad, zero_padding, zero_padding); + + *dst_len = src1_len + src2_len + zero_padding; + + sg_init_table(sg_in, 3); + sg_set_buf(&sg_in[0], src1, src1_len); + sg_set_buf(&sg_in[1], src2, src2_len); + sg_set_buf(&sg_in[2], pad, zero_padding); + ret = setup_sgtable(&sg_out, &prealloc_sg, dst, *dst_len); + if (ret) + goto out_tfm; + + crypto_blkcipher_setkey((void *)tfm, key, key_len); + iv = crypto_blkcipher_crt(tfm)->iv; + ivsize = crypto_blkcipher_ivsize(tfm); + memcpy(iv, aes_iv, ivsize); + + /* + print_hex_dump(KERN_ERR, "enc key: ", DUMP_PREFIX_NONE, 16, 1, + key, key_len, 1); + print_hex_dump(KERN_ERR, "enc src1: ", DUMP_PREFIX_NONE, 16, 1, + src1, src1_len, 1); + print_hex_dump(KERN_ERR, "enc src2: ", DUMP_PREFIX_NONE, 16, 1, + src2, src2_len, 1); + print_hex_dump(KERN_ERR, "enc pad: ", DUMP_PREFIX_NONE, 16, 1, + pad, zero_padding, 1); + */ + ret = crypto_blkcipher_encrypt(&desc, sg_out.sgl, sg_in, + src1_len + src2_len + zero_padding); + if (ret < 0) { + pr_err("ceph_aes_crypt2 failed %d\n", ret); + goto out_sg; + } + /* + print_hex_dump(KERN_ERR, "enc out: ", DUMP_PREFIX_NONE, 16, 1, + dst, *dst_len, 1); + */ + +out_sg: + teardown_sgtable(&sg_out); +out_tfm: + crypto_free_blkcipher(tfm); + return ret; +} + +static int ceph_aes_decrypt(const void *key, int key_len, + void *dst, size_t *dst_len, + const void *src, size_t src_len) +{ + struct sg_table sg_in; + struct scatterlist sg_out[2], prealloc_sg; + struct crypto_blkcipher *tfm = ceph_crypto_alloc_cipher(); + struct blkcipher_desc desc = { .tfm = tfm }; + char pad[16]; + void *iv; + int ivsize; + int ret; + int last_byte; + + if (IS_ERR(tfm)) + return PTR_ERR(tfm); + + sg_init_table(sg_out, 2); + sg_set_buf(&sg_out[0], dst, *dst_len); + sg_set_buf(&sg_out[1], pad, sizeof(pad)); + ret = setup_sgtable(&sg_in, &prealloc_sg, src, src_len); + if (ret) + goto out_tfm; + + crypto_blkcipher_setkey((void *)tfm, key, key_len); + iv = crypto_blkcipher_crt(tfm)->iv; + ivsize = crypto_blkcipher_ivsize(tfm); + memcpy(iv, aes_iv, ivsize); + + /* + print_hex_dump(KERN_ERR, "dec key: ", DUMP_PREFIX_NONE, 16, 1, + key, key_len, 1); + print_hex_dump(KERN_ERR, "dec in: ", DUMP_PREFIX_NONE, 16, 1, + src, src_len, 1); + */ + ret = crypto_blkcipher_decrypt(&desc, sg_out, sg_in.sgl, src_len); + if (ret < 0) { + pr_err("ceph_aes_decrypt failed %d\n", ret); + goto out_sg; + } + + if (src_len <= *dst_len) + last_byte = ((char *)dst)[src_len - 1]; + else + last_byte = pad[src_len - *dst_len - 1]; + if (last_byte <= 16 && src_len >= last_byte) { + *dst_len = src_len - last_byte; + } else { + pr_err("ceph_aes_decrypt got bad padding %d on src len %d\n", + last_byte, (int)src_len); + return -EPERM; /* bad padding */ + } + /* + print_hex_dump(KERN_ERR, "dec out: ", DUMP_PREFIX_NONE, 16, 1, + dst, *dst_len, 1); + */ + +out_sg: + teardown_sgtable(&sg_in); +out_tfm: + crypto_free_blkcipher(tfm); + return ret; +} + +static int ceph_aes_decrypt2(const void *key, int key_len, + void *dst1, size_t *dst1_len, + void *dst2, size_t *dst2_len, + const void *src, size_t src_len) +{ + struct sg_table sg_in; + struct scatterlist sg_out[3], prealloc_sg; + struct crypto_blkcipher *tfm = ceph_crypto_alloc_cipher(); + struct blkcipher_desc desc = { .tfm = tfm }; + char pad[16]; + void *iv; + int ivsize; + int ret; + int last_byte; + + if (IS_ERR(tfm)) + return PTR_ERR(tfm); + + sg_init_table(sg_out, 3); + sg_set_buf(&sg_out[0], dst1, *dst1_len); + sg_set_buf(&sg_out[1], dst2, *dst2_len); + sg_set_buf(&sg_out[2], pad, sizeof(pad)); + ret = setup_sgtable(&sg_in, &prealloc_sg, src, src_len); + if (ret) + goto out_tfm; + + crypto_blkcipher_setkey((void *)tfm, key, key_len); + iv = crypto_blkcipher_crt(tfm)->iv; + ivsize = crypto_blkcipher_ivsize(tfm); + memcpy(iv, aes_iv, ivsize); + + /* + print_hex_dump(KERN_ERR, "dec key: ", DUMP_PREFIX_NONE, 16, 1, + key, key_len, 1); + print_hex_dump(KERN_ERR, "dec in: ", DUMP_PREFIX_NONE, 16, 1, + src, src_len, 1); + */ + ret = crypto_blkcipher_decrypt(&desc, sg_out, sg_in.sgl, src_len); + if (ret < 0) { + pr_err("ceph_aes_decrypt failed %d\n", ret); + goto out_sg; + } + + if (src_len <= *dst1_len) + last_byte = ((char *)dst1)[src_len - 1]; + else if (src_len <= *dst1_len + *dst2_len) + last_byte = ((char *)dst2)[src_len - *dst1_len - 1]; + else + last_byte = pad[src_len - *dst1_len - *dst2_len - 1]; + if (last_byte <= 16 && src_len >= last_byte) { + src_len -= last_byte; + } else { + pr_err("ceph_aes_decrypt got bad padding %d on src len %d\n", + last_byte, (int)src_len); + return -EPERM; /* bad padding */ + } + + if (src_len < *dst1_len) { + *dst1_len = src_len; + *dst2_len = 0; + } else { + *dst2_len = src_len - *dst1_len; + } + /* + print_hex_dump(KERN_ERR, "dec out1: ", DUMP_PREFIX_NONE, 16, 1, + dst1, *dst1_len, 1); + print_hex_dump(KERN_ERR, "dec out2: ", DUMP_PREFIX_NONE, 16, 1, + dst2, *dst2_len, 1); + */ + +out_sg: + teardown_sgtable(&sg_in); +out_tfm: + crypto_free_blkcipher(tfm); + return ret; +} + + +int ceph_decrypt(struct ceph_crypto_key *secret, void *dst, size_t *dst_len, + const void *src, size_t src_len) +{ + switch (secret->type) { + case CEPH_CRYPTO_NONE: + if (*dst_len < src_len) + return -ERANGE; + memcpy(dst, src, src_len); + *dst_len = src_len; + return 0; + + case CEPH_CRYPTO_AES: + return ceph_aes_decrypt(secret->key, secret->len, dst, + dst_len, src, src_len); + + default: + return -EINVAL; + } +} + +int ceph_decrypt2(struct ceph_crypto_key *secret, + void *dst1, size_t *dst1_len, + void *dst2, size_t *dst2_len, + const void *src, size_t src_len) +{ + size_t t; + + switch (secret->type) { + case CEPH_CRYPTO_NONE: + if (*dst1_len + *dst2_len < src_len) + return -ERANGE; + t = min(*dst1_len, src_len); + memcpy(dst1, src, t); + *dst1_len = t; + src += t; + src_len -= t; + if (src_len) { + t = min(*dst2_len, src_len); + memcpy(dst2, src, t); + *dst2_len = t; + } + return 0; + + case CEPH_CRYPTO_AES: + return ceph_aes_decrypt2(secret->key, secret->len, + dst1, dst1_len, dst2, dst2_len, + src, src_len); + + default: + return -EINVAL; + } +} + +int ceph_encrypt(struct ceph_crypto_key *secret, void *dst, size_t *dst_len, + const void *src, size_t src_len) +{ + switch (secret->type) { + case CEPH_CRYPTO_NONE: + if (*dst_len < src_len) + return -ERANGE; + memcpy(dst, src, src_len); + *dst_len = src_len; + return 0; + + case CEPH_CRYPTO_AES: + return ceph_aes_encrypt(secret->key, secret->len, dst, + dst_len, src, src_len); + + default: + return -EINVAL; + } +} + +int ceph_encrypt2(struct ceph_crypto_key *secret, void *dst, size_t *dst_len, + const void *src1, size_t src1_len, + const void *src2, size_t src2_len) +{ + switch (secret->type) { + case CEPH_CRYPTO_NONE: + if (*dst_len < src1_len + src2_len) + return -ERANGE; + memcpy(dst, src1, src1_len); + memcpy(dst + src1_len, src2, src2_len); + *dst_len = src1_len + src2_len; + return 0; + + case CEPH_CRYPTO_AES: + return ceph_aes_encrypt2(secret->key, secret->len, dst, dst_len, + src1, src1_len, src2, src2_len); + + default: + return -EINVAL; + } +} + +static int ceph_key_preparse(struct key_preparsed_payload *prep) +{ + struct ceph_crypto_key *ckey; + size_t datalen = prep->datalen; + int ret; + void *p; + + ret = -EINVAL; + if (datalen <= 0 || datalen > 32767 || !prep->data) + goto err; + + ret = -ENOMEM; + ckey = kmalloc(sizeof(*ckey), GFP_KERNEL); + if (!ckey) + goto err; + + /* TODO ceph_crypto_key_decode should really take const input */ + p = (void *)prep->data; + ret = ceph_crypto_key_decode(ckey, &p, (char*)prep->data+datalen); + if (ret < 0) + goto err_ckey; + + prep->payload[0] = ckey; + prep->quotalen = datalen; + return 0; + +err_ckey: + kfree(ckey); +err: + return ret; +} + +static void ceph_key_free_preparse(struct key_preparsed_payload *prep) +{ + struct ceph_crypto_key *ckey = prep->payload[0]; + ceph_crypto_key_destroy(ckey); + kfree(ckey); +} + +static void ceph_key_destroy(struct key *key) +{ + struct ceph_crypto_key *ckey = key->payload.data; + + ceph_crypto_key_destroy(ckey); + kfree(ckey); +} + +struct key_type key_type_ceph = { + .name = "ceph", + .preparse = ceph_key_preparse, + .free_preparse = ceph_key_free_preparse, + .instantiate = generic_key_instantiate, + .destroy = ceph_key_destroy, +}; + +int ceph_crypto_init(void) { + return register_key_type(&key_type_ceph); +} + +void ceph_crypto_shutdown(void) { + unregister_key_type(&key_type_ceph); +} |