diff options
| -rw-r--r-- | crypto/krb5/internal.h | 13 | ||||
| -rw-r--r-- | crypto/krb5/rfc3961_simplified.c | 146 |
2 files changed, 159 insertions, 0 deletions
diff --git a/crypto/krb5/internal.h b/crypto/krb5/internal.h index ae00588619a8..c8deb112b604 100644 --- a/crypto/krb5/internal.h +++ b/crypto/krb5/internal.h @@ -7,6 +7,8 @@ #include <linux/scatterlist.h> #include <crypto/krb5.h> +#include <crypto/hash.h> +#include <crypto/skcipher.h> /* * Profile used for key derivation and encryption. @@ -137,6 +139,8 @@ int krb5_derive_Ki(const struct krb5_enctype *krb5, const struct krb5_buffer *TK */ extern const struct krb5_crypto_profile rfc3961_simplified_profile; +int crypto_shash_update_sg(struct shash_desc *desc, struct scatterlist *sg, + size_t offset, size_t len); int authenc_derive_encrypt_keys(const struct krb5_enctype *krb5, const struct krb5_buffer *TK, unsigned int usage, @@ -156,3 +160,12 @@ int rfc3961_load_checksum_key(const struct krb5_enctype *krb5, const struct krb5_buffer *Kc, struct krb5_buffer *setkey, gfp_t gfp); +ssize_t krb5_aead_encrypt(const struct krb5_enctype *krb5, + struct crypto_aead *aead, + struct scatterlist *sg, unsigned int nr_sg, size_t sg_len, + size_t data_offset, size_t data_len, + bool preconfounded); +int krb5_aead_decrypt(const struct krb5_enctype *krb5, + struct crypto_aead *aead, + struct scatterlist *sg, unsigned int nr_sg, + size_t *_offset, size_t *_len); diff --git a/crypto/krb5/rfc3961_simplified.c b/crypto/krb5/rfc3961_simplified.c index 335c5bb6904f..58323ce5838a 100644 --- a/crypto/krb5/rfc3961_simplified.c +++ b/crypto/krb5/rfc3961_simplified.c @@ -66,7 +66,10 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include <linux/random.h> +#include <linux/skbuff.h> #include <linux/slab.h> +#include <linux/highmem.h> #include <linux/lcm.h> #include <linux/rtnetlink.h> #include <crypto/authenc.h> @@ -77,6 +80,31 @@ /* Maximum blocksize for the supported crypto algorithms */ #define KRB5_MAX_BLOCKSIZE (16) +int crypto_shash_update_sg(struct shash_desc *desc, struct scatterlist *sg, + size_t offset, size_t len) +{ + do { + int ret; + + if (offset < sg->length) { + struct page *page = sg_page(sg); + void *p = kmap_local_page(page); + void *q = p + sg->offset + offset; + size_t seg = min_t(size_t, len, sg->length - offset); + + ret = crypto_shash_update(desc, q, seg); + kunmap_local(p); + if (ret < 0) + return ret; + len -= seg; + offset = 0; + } else { + offset -= sg->length; + } + } while (len > 0 && (sg = sg_next(sg))); + return 0; +} + static int rfc3961_do_encrypt(struct crypto_sync_skcipher *tfm, void *iv, const struct krb5_buffer *in, struct krb5_buffer *out) { @@ -509,6 +537,122 @@ int rfc3961_load_checksum_key(const struct krb5_enctype *krb5, return -ENOMEM; return 0; } + +/* + * Apply encryption and checksumming functions to part of a scatterlist. + */ +ssize_t krb5_aead_encrypt(const struct krb5_enctype *krb5, + struct crypto_aead *aead, + struct scatterlist *sg, unsigned int nr_sg, size_t sg_len, + size_t data_offset, size_t data_len, + bool preconfounded) +{ + struct aead_request *req; + ssize_t ret, done; + size_t bsize, base_len, secure_offset, secure_len, pad_len, cksum_offset; + void *buffer; + u8 *iv; + + if (WARN_ON(data_offset != krb5->conf_len)) + return -EINVAL; /* Data is in wrong place */ + + secure_offset = 0; + base_len = krb5->conf_len + data_len; + pad_len = 0; + secure_len = base_len + pad_len; + cksum_offset = secure_len; + if (WARN_ON(cksum_offset + krb5->cksum_len > sg_len)) + return -EFAULT; + + bsize = krb5_aead_size(aead) + + krb5_aead_ivsize(aead); + buffer = kzalloc(bsize, GFP_NOFS); + if (!buffer) + return -ENOMEM; + + /* Insert the confounder into the buffer */ + ret = -EFAULT; + if (!preconfounded) { + get_random_bytes(buffer, krb5->conf_len); + done = sg_pcopy_from_buffer(sg, nr_sg, buffer, krb5->conf_len, + secure_offset); + if (done != krb5->conf_len) + goto error; + } + + /* We may need to pad out to the crypto blocksize. */ + if (pad_len) { + done = sg_zero_buffer(sg, nr_sg, pad_len, data_offset + data_len); + if (done != pad_len) + goto error; + } + + /* Hash and encrypt the message. */ + req = buffer; + iv = buffer + krb5_aead_size(aead); + + aead_request_set_tfm(req, aead); + aead_request_set_callback(req, 0, NULL, NULL); + aead_request_set_crypt(req, sg, sg, secure_len, iv); + ret = crypto_aead_encrypt(req); + if (ret < 0) + goto error; + + ret = secure_len + krb5->cksum_len; + +error: + kfree_sensitive(buffer); + return ret; +} + +/* + * Apply decryption and checksumming functions to a message. The offset and + * length are updated to reflect the actual content of the encrypted region. + */ +int krb5_aead_decrypt(const struct krb5_enctype *krb5, + struct crypto_aead *aead, + struct scatterlist *sg, unsigned int nr_sg, + size_t *_offset, size_t *_len) +{ + struct aead_request *req; + size_t bsize; + void *buffer; + int ret; + u8 *iv; + + if (WARN_ON(*_offset != 0)) + return -EINVAL; /* Can't set offset on aead */ + + if (*_len < krb5->conf_len + krb5->cksum_len) + return -EPROTO; + + bsize = krb5_aead_size(aead) + + krb5_aead_ivsize(aead); + buffer = kzalloc(bsize, GFP_NOFS); + if (!buffer) + return -ENOMEM; + + /* Decrypt the message and verify its checksum. */ + req = buffer; + iv = buffer + krb5_aead_size(aead); + + aead_request_set_tfm(req, aead); + aead_request_set_callback(req, 0, NULL, NULL); + aead_request_set_crypt(req, sg, sg, *_len, iv); + ret = crypto_aead_decrypt(req); + if (ret < 0) + goto error; + + /* Adjust the boundaries of the data. */ + *_offset += krb5->conf_len; + *_len -= krb5->conf_len + krb5->cksum_len; + ret = 0; + +error: + kfree_sensitive(buffer); + return ret; +} + const struct krb5_crypto_profile rfc3961_simplified_profile = { .calc_PRF = rfc3961_calc_PRF, .calc_Kc = rfc3961_calc_DK, @@ -518,4 +662,6 @@ const struct krb5_crypto_profile rfc3961_simplified_profile = { .load_encrypt_keys = authenc_load_encrypt_keys, .derive_checksum_key = rfc3961_derive_checksum_key, .load_checksum_key = rfc3961_load_checksum_key, + .encrypt = krb5_aead_encrypt, + .decrypt = krb5_aead_decrypt, }; |