diff options
Diffstat (limited to 'crypto/drbg.c')
| -rw-r--r-- | crypto/drbg.c | 269 |
1 files changed, 184 insertions, 85 deletions
diff --git a/crypto/drbg.c b/crypto/drbg.c index 0a3538f..f752da3 100644 --- a/crypto/drbg.c +++ b/crypto/drbg.c @@ -252,10 +252,16 @@ MODULE_ALIAS_CRYPTO("drbg_nopr_ctr_aes192"); MODULE_ALIAS_CRYPTO("drbg_pr_ctr_aes128"); MODULE_ALIAS_CRYPTO("drbg_nopr_ctr_aes128"); -static int drbg_kcapi_sym(struct drbg_state *drbg, const unsigned char *key, - unsigned char *outval, const struct drbg_string *in); +static void drbg_kcapi_symsetkey(struct drbg_state *drbg, + const unsigned char *key); +static int drbg_kcapi_sym(struct drbg_state *drbg, unsigned char *outval, + const struct drbg_string *in); static int drbg_init_sym_kernel(struct drbg_state *drbg); static int drbg_fini_sym_kernel(struct drbg_state *drbg); +static int drbg_kcapi_sym_ctr(struct drbg_state *drbg, + u8 *inbuf, u32 inbuflen, + u8 *outbuf, u32 outlen); +#define DRBG_CTR_NULL_LEN 128 /* BCC function for CTR DRBG as defined in 10.4.3 */ static int drbg_ctr_bcc(struct drbg_state *drbg, @@ -270,6 +276,7 @@ static int drbg_ctr_bcc(struct drbg_state *drbg, drbg_string_fill(&data, out, drbg_blocklen(drbg)); /* 10.4.3 step 2 / 4 */ + drbg_kcapi_symsetkey(drbg, key); list_for_each_entry(curr, in, list) { const unsigned char *pos = curr->buf; size_t len = curr->len; @@ -278,7 +285,7 @@ static int drbg_ctr_bcc(struct drbg_state *drbg, /* 10.4.3 step 4.2 */ if (drbg_blocklen(drbg) == cnt) { cnt = 0; - ret = drbg_kcapi_sym(drbg, key, out, &data); + ret = drbg_kcapi_sym(drbg, out, &data); if (ret) return ret; } @@ -290,7 +297,7 @@ static int drbg_ctr_bcc(struct drbg_state *drbg, } /* 10.4.3 step 4.2 for last block */ if (cnt) - ret = drbg_kcapi_sym(drbg, key, out, &data); + ret = drbg_kcapi_sym(drbg, out, &data); return ret; } @@ -425,6 +432,7 @@ static int drbg_ctr_df(struct drbg_state *drbg, /* 10.4.2 step 12: overwriting of outval is implemented in next step */ /* 10.4.2 step 13 */ + drbg_kcapi_symsetkey(drbg, temp); while (generated_len < bytes_to_return) { short blocklen = 0; /* @@ -432,7 +440,7 @@ static int drbg_ctr_df(struct drbg_state *drbg, * implicit as the key is only drbg_blocklen in size based on * the implementation of the cipher function callback */ - ret = drbg_kcapi_sym(drbg, temp, X, &cipherin); + ret = drbg_kcapi_sym(drbg, X, &cipherin); if (ret) goto out; blocklen = (drbg_blocklen(drbg) < @@ -476,49 +484,47 @@ static int drbg_ctr_update(struct drbg_state *drbg, struct list_head *seed, unsigned char *temp = drbg->scratchpad; unsigned char *df_data = drbg->scratchpad + drbg_statelen(drbg) + drbg_blocklen(drbg); - unsigned char *temp_p, *df_data_p; /* pointer to iterate over buffers */ - unsigned int len = 0; - struct drbg_string cipherin; if (3 > reseed) memset(df_data, 0, drbg_statelen(drbg)); - /* 10.2.1.3.2 step 2 and 10.2.1.4.2 step 2 */ - if (seed) { - ret = drbg_ctr_df(drbg, df_data, drbg_statelen(drbg), seed); + if (!reseed) { + /* + * The DRBG uses the CTR mode of the underlying AES cipher. The + * CTR mode increments the counter value after the AES operation + * but SP800-90A requires that the counter is incremented before + * the AES operation. Hence, we increment it at the time we set + * it by one. + */ + crypto_inc(drbg->V, drbg_blocklen(drbg)); + + ret = crypto_skcipher_setkey(drbg->ctr_handle, drbg->C, + drbg_keylen(drbg)); if (ret) goto out; } - drbg_string_fill(&cipherin, drbg->V, drbg_blocklen(drbg)); - /* - * 10.2.1.3.2 steps 2 and 3 are already covered as the allocation - * zeroizes all memory during initialization - */ - while (len < (drbg_statelen(drbg))) { - /* 10.2.1.2 step 2.1 */ - crypto_inc(drbg->V, drbg_blocklen(drbg)); - /* - * 10.2.1.2 step 2.2 */ - ret = drbg_kcapi_sym(drbg, drbg->C, temp + len, &cipherin); + /* 10.2.1.3.2 step 2 and 10.2.1.4.2 step 2 */ + if (seed) { + ret = drbg_ctr_df(drbg, df_data, drbg_statelen(drbg), seed); if (ret) goto out; - /* 10.2.1.2 step 2.3 and 3 */ - len += drbg_blocklen(drbg); } - /* 10.2.1.2 step 4 */ - temp_p = temp; - df_data_p = df_data; - for (len = 0; len < drbg_statelen(drbg); len++) { - *temp_p ^= *df_data_p; - df_data_p++; temp_p++; - } + ret = drbg_kcapi_sym_ctr(drbg, df_data, drbg_statelen(drbg), + temp, drbg_statelen(drbg)); + if (ret) + return ret; /* 10.2.1.2 step 5 */ - memcpy(drbg->C, temp, drbg_keylen(drbg)); + ret = crypto_skcipher_setkey(drbg->ctr_handle, temp, + drbg_keylen(drbg)); + if (ret) + goto out; /* 10.2.1.2 step 6 */ memcpy(drbg->V, temp + drbg_keylen(drbg), drbg_blocklen(drbg)); + /* See above: increment counter by one to compensate timing of CTR op */ + crypto_inc(drbg->V, drbg_blocklen(drbg)); ret = 0; out: @@ -537,9 +543,8 @@ static int drbg_ctr_generate(struct drbg_state *drbg, unsigned char *buf, unsigned int buflen, struct list_head *addtl) { - int len = 0; - int ret = 0; - struct drbg_string data; + int ret; + int len = min_t(int, buflen, INT_MAX); /* 10.2.1.5.2 step 2 */ if (addtl && !list_empty(addtl)) { @@ -549,33 +554,16 @@ static int drbg_ctr_generate(struct drbg_state *drbg, } /* 10.2.1.5.2 step 4.1 */ - crypto_inc(drbg->V, drbg_blocklen(drbg)); - drbg_string_fill(&data, drbg->V, drbg_blocklen(drbg)); - while (len < buflen) { - int outlen = 0; - /* 10.2.1.5.2 step 4.2 */ - ret = drbg_kcapi_sym(drbg, drbg->C, drbg->scratchpad, &data); - if (ret) { - len = ret; - goto out; - } - outlen = (drbg_blocklen(drbg) < (buflen - len)) ? - drbg_blocklen(drbg) : (buflen - len); - /* 10.2.1.5.2 step 4.3 */ - memcpy(buf + len, drbg->scratchpad, outlen); - len += outlen; - /* 10.2.1.5.2 step 6 */ - if (len < buflen) - crypto_inc(drbg->V, drbg_blocklen(drbg)); - } + ret = drbg_kcapi_sym_ctr(drbg, drbg->ctr_null_value, DRBG_CTR_NULL_LEN, + buf, len); + if (ret) + return ret; /* 10.2.1.5.2 step 6 */ ret = drbg_ctr_update(drbg, NULL, 3); if (ret) len = ret; -out: - memset(drbg->scratchpad, 0, drbg_blocklen(drbg)); return len; } @@ -1145,11 +1133,11 @@ static inline void drbg_dealloc_state(struct drbg_state *drbg) if (!drbg) return; kzfree(drbg->V); - drbg->V = NULL; + drbg->Vbuf = NULL; kzfree(drbg->C); - drbg->C = NULL; - kzfree(drbg->scratchpad); - drbg->scratchpad = NULL; + drbg->Cbuf = NULL; + kzfree(drbg->scratchpadbuf); + drbg->scratchpadbuf = NULL; drbg->reseed_ctr = 0; drbg->d_ops = NULL; drbg->core = NULL; @@ -1185,12 +1173,18 @@ static inline int drbg_alloc_state(struct drbg_state *drbg) goto err; } - drbg->V = kmalloc(drbg_statelen(drbg), GFP_KERNEL); - if (!drbg->V) - goto err; - drbg->C = kmalloc(drbg_statelen(drbg), GFP_KERNEL); - if (!drbg->C) + ret = drbg->d_ops->crypto_init(drbg); + if (ret < 0) goto err; + + drbg->Vbuf = kmalloc(drbg_statelen(drbg) + ret, GFP_KERNEL); + if (!drbg->Vbuf) + goto fini; + drbg->V = PTR_ALIGN(drbg->Vbuf, ret + 1); + drbg->Cbuf = kmalloc(drbg_statelen(drbg) + ret, GFP_KERNEL); + if (!drbg->Cbuf) + goto fini; + drbg->C = PTR_ALIGN(drbg->Cbuf, ret + 1); /* scratchpad is only generated for CTR and Hash */ if (drbg->core->flags & DRBG_HMAC) sb_size = 0; @@ -1204,13 +1198,16 @@ static inline int drbg_alloc_state(struct drbg_state *drbg) sb_size = drbg_statelen(drbg) + drbg_blocklen(drbg); if (0 < sb_size) { - drbg->scratchpad = kzalloc(sb_size, GFP_KERNEL); - if (!drbg->scratchpad) - goto err; + drbg->scratchpadbuf = kzalloc(sb_size + ret, GFP_KERNEL); + if (!drbg->scratchpadbuf) + goto fini; + drbg->scratchpad = PTR_ALIGN(drbg->scratchpadbuf, ret + 1); } return 0; +fini: + drbg->d_ops->crypto_fini(drbg); err: drbg_dealloc_state(drbg); return ret; @@ -1478,10 +1475,6 @@ static int drbg_instantiate(struct drbg_state *drbg, struct drbg_string *pers, if (ret) goto unlock; - ret = -EFAULT; - if (drbg->d_ops->crypto_init(drbg)) - goto err; - ret = drbg_prepare_hrng(drbg); if (ret) goto free_everything; @@ -1505,8 +1498,6 @@ static int drbg_instantiate(struct drbg_state *drbg, struct drbg_string *pers, mutex_unlock(&drbg->drbg_mutex); return ret; -err: - drbg_dealloc_state(drbg); unlock: mutex_unlock(&drbg->drbg_mutex); return ret; @@ -1591,7 +1582,8 @@ static int drbg_init_hash_kernel(struct drbg_state *drbg) sdesc->shash.tfm = tfm; sdesc->shash.flags = 0; drbg->priv_data = sdesc; - return 0; + + return crypto_shash_alignmask(tfm); } static int drbg_fini_hash_kernel(struct drbg_state *drbg) @@ -1627,10 +1619,45 @@ static int drbg_kcapi_hash(struct drbg_state *drbg, unsigned char *outval, #endif /* (CONFIG_CRYPTO_DRBG_HASH || CONFIG_CRYPTO_DRBG_HMAC) */ #ifdef CONFIG_CRYPTO_DRBG_CTR +static int drbg_fini_sym_kernel(struct drbg_state *drbg) +{ + struct crypto_cipher *tfm = + (struct crypto_cipher *)drbg->priv_data; + if (tfm) + crypto_free_cipher(tfm); + drbg->priv_data = NULL; + + if (drbg->ctr_handle) + crypto_free_skcipher(drbg->ctr_handle); + drbg->ctr_handle = NULL; + + if (drbg->ctr_req) + skcipher_request_free(drbg->ctr_req); + drbg->ctr_req = NULL; + + kfree(drbg->ctr_null_value_buf); + drbg->ctr_null_value = NULL; + + return 0; +} + +static void drbg_skcipher_cb(struct crypto_async_request *req, int error) +{ + struct drbg_state *drbg = req->data; + + if (error == -EINPROGRESS) + return; + drbg->ctr_async_err = error; + complete(&drbg->ctr_completion); +} + static int drbg_init_sym_kernel(struct drbg_state *drbg) { - int ret = 0; struct crypto_cipher *tfm; + struct crypto_skcipher *sk_tfm; + struct skcipher_request *req; + unsigned int alignmask; + char ctr_name[CRYPTO_MAX_ALG_NAME]; tfm = crypto_alloc_cipher(drbg->core->backend_cra_name, 0, 0); if (IS_ERR(tfm)) { @@ -1640,31 +1667,103 @@ static int drbg_init_sym_kernel(struct drbg_state *drbg) } BUG_ON(drbg_blocklen(drbg) != crypto_cipher_blocksize(tfm)); drbg->priv_data = tfm; - return ret; + + if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)", + drbg->core->backend_cra_name) >= CRYPTO_MAX_ALG_NAME) { + drbg_fini_sym_kernel(drbg); + return -EINVAL; + } + sk_tfm = crypto_alloc_skcipher(ctr_name, 0, 0); + if (IS_ERR(sk_tfm)) { + pr_info("DRBG: could not allocate CTR cipher TFM handle: %s\n", + ctr_name); + drbg_fini_sym_kernel(drbg); + return PTR_ERR(sk_tfm); + } + drbg->ctr_handle = sk_tfm; + + req = skcipher_request_alloc(sk_tfm, GFP_KERNEL); + if (!req) { + pr_info("DRBG: could not allocate request queue\n"); + drbg_fini_sym_kernel(drbg); + return -ENOMEM; + } + drbg->ctr_req = req; + skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG, + drbg_skcipher_cb, drbg); + + alignmask = crypto_skcipher_alignmask(sk_tfm); + drbg->ctr_null_value_buf = kzalloc(DRBG_CTR_NULL_LEN + alignmask, + GFP_KERNEL); + if (!drbg->ctr_null_value_buf) { + drbg_fini_sym_kernel(drbg); + return -ENOMEM; + } + drbg->ctr_null_value = (u8 *)PTR_ALIGN(drbg->ctr_null_value_buf, + alignmask + 1); + + return alignmask; } -static int drbg_fini_sym_kernel(struct drbg_state *drbg) +static void drbg_kcapi_symsetkey(struct drbg_state *drbg, + const unsigned char *key) { struct crypto_cipher *tfm = (struct crypto_cipher *)drbg->priv_data; - if (tfm) - crypto_free_cipher(tfm); - drbg->priv_data = NULL; - return 0; + + crypto_cipher_setkey(tfm, key, (drbg_keylen(drbg))); } -static int drbg_kcapi_sym(struct drbg_state *drbg, const unsigned char *key, - unsigned char *outval, const struct drbg_string *in) +static int drbg_kcapi_sym(struct drbg_state *drbg, unsigned char *outval, + const struct drbg_string *in) { struct crypto_cipher *tfm = (struct crypto_cipher *)drbg->priv_data; - crypto_cipher_setkey(tfm, key, (drbg_keylen(drbg))); /* there is only component in *in */ BUG_ON(in->len < drbg_blocklen(drbg)); crypto_cipher_encrypt_one(tfm, outval, in->buf); return 0; } + +static int drbg_kcapi_sym_ctr(struct drbg_state *drbg, + u8 *inbuf, u32 inlen, + u8 *outbuf, u32 outlen) +{ + struct scatterlist sg_in; + + sg_init_one(&sg_in, inbuf, inlen); + + while (outlen) { + u32 cryptlen = min_t(u32, inlen, outlen); + struct scatterlist sg_out; + int ret; + + sg_init_one(&sg_out, outbuf, cryptlen); + skcipher_request_set_crypt(drbg->ctr_req, &sg_in, &sg_out, + cryptlen, drbg->V); + ret = crypto_skcipher_encrypt(drbg->ctr_req); + switch (ret) { + case 0: + break; + case -EINPROGRESS: + case -EBUSY: + ret = wait_for_completion_interruptible( + &drbg->ctr_completion); + if (!ret && !drbg->ctr_async_err) { + reinit_completion(&drbg->ctr_completion); + break; + } + default: + return ret; + } + init_completion(&drbg->ctr_completion); + + outlen -= cryptlen; + } + + return 0; +} #endif /* CONFIG_CRYPTO_DRBG_CTR */ /*************************************************************** |
