#include "internal/thread_once.h"
/*
- * Mapping of NIST SP 800-90A DRBG to OpenSSL RAND_METHOD.
+ * Implementation of NIST SP 800-90A CTR DRBG.
*/
-
-/*
- * The default global DRBG and its auto-init/auto-cleanup.
- */
-static DRBG_CTX ossl_drbg;
-
-static CRYPTO_ONCE ossl_drbg_init = CRYPTO_ONCE_STATIC_INIT;
-
-DEFINE_RUN_ONCE_STATIC(do_ossl_drbg_init)
-{
- ossl_drbg.lock = CRYPTO_THREAD_lock_new();
- return ossl_drbg.lock != NULL;
-}
-
-void rand_drbg_cleanup(void)
-{
- CRYPTO_THREAD_lock_free(ossl_drbg.lock);
-}
-
-static void inc_128(DRBG_CTR_CTX *cctx)
+static void inc_128(RAND_DRBG_CTR *ctr)
{
int i;
unsigned char c;
- unsigned char *p = &cctx->V[15];
+ unsigned char *p = &ctr->V[15];
for (i = 0; i < 16; i++, p--) {
c = *p;
}
}
-static void ctr_XOR(DRBG_CTR_CTX *cctx, const unsigned char *in, size_t inlen)
+static void ctr_XOR(RAND_DRBG_CTR *ctr, const unsigned char *in, size_t inlen)
{
size_t i, n;
* Any zero padding will have no effect on the result as we
* are XORing. So just process however much input we have.
*/
- n = inlen < cctx->keylen ? inlen : cctx->keylen;
+ n = inlen < ctr->keylen ? inlen : ctr->keylen;
for (i = 0; i < n; i++)
- cctx->K[i] ^= in[i];
- if (inlen <= cctx->keylen)
+ ctr->K[i] ^= in[i];
+ if (inlen <= ctr->keylen)
return;
- n = inlen - cctx->keylen;
+ n = inlen - ctr->keylen;
if (n > 16) {
/* Should never happen */
n = 16;
}
for (i = 0; i < n; i++)
- cctx->V[i] ^= in[i + cctx->keylen];
+ ctr->V[i] ^= in[i + ctr->keylen];
}
/*
* Process a complete block using BCC algorithm of SP 800-90A 10.3.3
*/
-static void ctr_BCC_block(DRBG_CTR_CTX *cctx, unsigned char *out,
+static void ctr_BCC_block(RAND_DRBG_CTR *ctr, unsigned char *out,
const unsigned char *in)
{
int i;
for (i = 0; i < 16; i++)
out[i] ^= in[i];
- AES_encrypt(out, out, &cctx->df_ks);
+ AES_encrypt(out, out, &ctr->df_ks);
}
/*
* Handle several BCC operations for as much data as we need for K and X
*/
-static void ctr_BCC_blocks(DRBG_CTR_CTX *cctx, const unsigned char *in)
+static void ctr_BCC_blocks(RAND_DRBG_CTR *ctr, const unsigned char *in)
{
- ctr_BCC_block(cctx, cctx->KX, in);
- ctr_BCC_block(cctx, cctx->KX + 16, in);
- if (cctx->keylen != 16)
- ctr_BCC_block(cctx, cctx->KX + 32, in);
+ ctr_BCC_block(ctr, ctr->KX, in);
+ ctr_BCC_block(ctr, ctr->KX + 16, in);
+ if (ctr->keylen != 16)
+ ctr_BCC_block(ctr, ctr->KX + 32, in);
}
/*
* Initialise BCC blocks: these have the value 0,1,2 in leftmost positions:
* see 10.3.1 stage 7.
*/
-static void ctr_BCC_init(DRBG_CTR_CTX *cctx)
+static void ctr_BCC_init(RAND_DRBG_CTR *ctr)
{
- memset(cctx->KX, 0, 48);
- memset(cctx->bltmp, 0, 16);
- ctr_BCC_block(cctx, cctx->KX, cctx->bltmp);
- cctx->bltmp[3] = 1;
- ctr_BCC_block(cctx, cctx->KX + 16, cctx->bltmp);
- if (cctx->keylen != 16) {
- cctx->bltmp[3] = 2;
- ctr_BCC_block(cctx, cctx->KX + 32, cctx->bltmp);
+ memset(ctr->KX, 0, 48);
+ memset(ctr->bltmp, 0, 16);
+ ctr_BCC_block(ctr, ctr->KX, ctr->bltmp);
+ ctr->bltmp[3] = 1;
+ ctr_BCC_block(ctr, ctr->KX + 16, ctr->bltmp);
+ if (ctr->keylen != 16) {
+ ctr->bltmp[3] = 2;
+ ctr_BCC_block(ctr, ctr->KX + 32, ctr->bltmp);
}
}
/*
* Process several blocks into BCC algorithm, some possibly partial
*/
-static void ctr_BCC_update(DRBG_CTR_CTX *cctx,
+static void ctr_BCC_update(RAND_DRBG_CTR *ctr,
const unsigned char *in, size_t inlen)
{
if (in == NULL || inlen == 0)
return;
/* If we have partial block handle it first */
- if (cctx->bltmp_pos) {
- size_t left = 16 - cctx->bltmp_pos;
+ if (ctr->bltmp_pos) {
+ size_t left = 16 - ctr->bltmp_pos;
/* If we now have a complete block process it */
if (inlen >= left) {
- memcpy(cctx->bltmp + cctx->bltmp_pos, in, left);
- ctr_BCC_blocks(cctx, cctx->bltmp);
- cctx->bltmp_pos = 0;
+ memcpy(ctr->bltmp + ctr->bltmp_pos, in, left);
+ ctr_BCC_blocks(ctr, ctr->bltmp);
+ ctr->bltmp_pos = 0;
inlen -= left;
in += left;
}
/* Process zero or more complete blocks */
for (; inlen >= 16; in += 16, inlen -= 16) {
- ctr_BCC_blocks(cctx, in);
+ ctr_BCC_blocks(ctr, in);
}
/* Copy any remaining partial block to the temporary buffer */
if (inlen > 0) {
- memcpy(cctx->bltmp + cctx->bltmp_pos, in, inlen);
- cctx->bltmp_pos += inlen;
+ memcpy(ctr->bltmp + ctr->bltmp_pos, in, inlen);
+ ctr->bltmp_pos += inlen;
}
}
-static void ctr_BCC_final(DRBG_CTR_CTX *cctx)
+static void ctr_BCC_final(RAND_DRBG_CTR *ctr)
{
- if (cctx->bltmp_pos) {
- memset(cctx->bltmp + cctx->bltmp_pos, 0, 16 - cctx->bltmp_pos);
- ctr_BCC_blocks(cctx, cctx->bltmp);
+ if (ctr->bltmp_pos) {
+ memset(ctr->bltmp + ctr->bltmp_pos, 0, 16 - ctr->bltmp_pos);
+ ctr_BCC_blocks(ctr, ctr->bltmp);
}
}
-static void ctr_df(DRBG_CTR_CTX *cctx,
+static void ctr_df(RAND_DRBG_CTR *ctr,
const unsigned char *in1, size_t in1len,
const unsigned char *in2, size_t in2len,
const unsigned char *in3, size_t in3len)
{
static unsigned char c80 = 0x80;
size_t inlen;
- unsigned char *p = cctx->bltmp;
+ unsigned char *p = ctr->bltmp;
- ctr_BCC_init(cctx);
+ ctr_BCC_init(ctr);
if (in1 == NULL)
in1len = 0;
if (in2 == NULL)
*p++ = 0;
*p++ = 0;
*p++ = 0;
- *p = (unsigned char)((cctx->keylen + 16) & 0xff);
- cctx->bltmp_pos = 8;
- ctr_BCC_update(cctx, in1, in1len);
- ctr_BCC_update(cctx, in2, in2len);
- ctr_BCC_update(cctx, in3, in3len);
- ctr_BCC_update(cctx, &c80, 1);
- ctr_BCC_final(cctx);
+ *p = (unsigned char)((ctr->keylen + 16) & 0xff);
+ ctr->bltmp_pos = 8;
+ ctr_BCC_update(ctr, in1, in1len);
+ ctr_BCC_update(ctr, in2, in2len);
+ ctr_BCC_update(ctr, in3, in3len);
+ ctr_BCC_update(ctr, &c80, 1);
+ ctr_BCC_final(ctr);
/* Set up key K */
- AES_set_encrypt_key(cctx->KX, cctx->keylen * 8, &cctx->df_kxks);
+ AES_set_encrypt_key(ctr->KX, ctr->keylen * 8, &ctr->df_kxks);
/* X follows key K */
- AES_encrypt(cctx->KX + cctx->keylen, cctx->KX, &cctx->df_kxks);
- AES_encrypt(cctx->KX, cctx->KX + 16, &cctx->df_kxks);
- if (cctx->keylen != 16)
- AES_encrypt(cctx->KX + 16, cctx->KX + 32, &cctx->df_kxks);
+ AES_encrypt(ctr->KX + ctr->keylen, ctr->KX, &ctr->df_kxks);
+ AES_encrypt(ctr->KX, ctr->KX + 16, &ctr->df_kxks);
+ if (ctr->keylen != 16)
+ AES_encrypt(ctr->KX + 16, ctr->KX + 32, &ctr->df_kxks);
}
/*
* NB the no-df Update in SP800-90A specifies a constant input length
* of seedlen, however other uses of this algorithm pad the input with
* zeroes if necessary and have up to two parameters XORed together,
- * handle both cases in this function instead.
+ * so we handle both cases in this function instead.
*/
-static void ctr_update(DRBG_CTX *dctx,
+static void ctr_update(RAND_DRBG *drbg,
const unsigned char *in1, size_t in1len,
const unsigned char *in2, size_t in2len,
const unsigned char *nonce, size_t noncelen)
{
- DRBG_CTR_CTX *cctx = &dctx->ctr;
+ RAND_DRBG_CTR *ctr = &drbg->ctr;
/* ks is already setup for correct key */
- inc_128(cctx);
- AES_encrypt(cctx->V, cctx->K, &cctx->ks);
+ inc_128(ctr);
+ AES_encrypt(ctr->V, ctr->K, &ctr->ks);
/* If keylen longer than 128 bits need extra encrypt */
- if (cctx->keylen != 16) {
- inc_128(cctx);
- AES_encrypt(cctx->V, cctx->K + 16, &cctx->ks);
+ if (ctr->keylen != 16) {
+ inc_128(ctr);
+ AES_encrypt(ctr->V, ctr->K + 16, &ctr->ks);
}
- inc_128(cctx);
- AES_encrypt(cctx->V, cctx->V, &cctx->ks);
+ inc_128(ctr);
+ AES_encrypt(ctr->V, ctr->V, &ctr->ks);
/* If 192 bit key part of V is on end of K */
- if (cctx->keylen == 24) {
- memcpy(cctx->V + 8, cctx->V, 8);
- memcpy(cctx->V, cctx->K + 24, 8);
+ if (ctr->keylen == 24) {
+ memcpy(ctr->V + 8, ctr->V, 8);
+ memcpy(ctr->V, ctr->K + 24, 8);
}
- if (dctx->flags & RAND_DRBG_FLAG_CTR_USE_DF) {
+ if (drbg->flags & RAND_DRBG_FLAG_CTR_USE_DF) {
/* If no input reuse existing derived value */
if (in1 != NULL || nonce != NULL || in2 != NULL)
- ctr_df(cctx, in1, in1len, nonce, noncelen, in2, in2len);
+ ctr_df(ctr, in1, in1len, nonce, noncelen, in2, in2len);
/* If this a reuse input in1len != 0 */
if (in1len)
- ctr_XOR(cctx, cctx->KX, dctx->seedlen);
+ ctr_XOR(ctr, ctr->KX, drbg->seedlen);
} else {
- ctr_XOR(cctx, in1, in1len);
- ctr_XOR(cctx, in2, in2len);
+ ctr_XOR(ctr, in1, in1len);
+ ctr_XOR(ctr, in2, in2len);
}
- AES_set_encrypt_key(cctx->K, dctx->strength, &cctx->ks);
+ AES_set_encrypt_key(ctr->K, drbg->strength, &ctr->ks);
}
-int ctr_instantiate(DRBG_CTX *dctx,
+int ctr_instantiate(RAND_DRBG *drbg,
const unsigned char *ent, size_t entlen,
const unsigned char *nonce, size_t noncelen,
const unsigned char *pers, size_t perslen)
{
- DRBG_CTR_CTX *cctx = &dctx->ctr;
+ RAND_DRBG_CTR *ctr = &drbg->ctr;
- memset(cctx->K, 0, sizeof(cctx->K));
- memset(cctx->V, 0, sizeof(cctx->V));
- AES_set_encrypt_key(cctx->K, dctx->strength, &cctx->ks);
- ctr_update(dctx, ent, entlen, pers, perslen, nonce, noncelen);
+ if (ent == NULL)
+ return 0;
+
+ memset(ctr->K, 0, sizeof(ctr->K));
+ memset(ctr->V, 0, sizeof(ctr->V));
+ AES_set_encrypt_key(ctr->K, drbg->strength, &ctr->ks);
+ ctr_update(drbg, ent, entlen, pers, perslen, nonce, noncelen);
return 1;
}
-int ctr_reseed(DRBG_CTX *dctx,
+int ctr_reseed(RAND_DRBG *drbg,
const unsigned char *ent, size_t entlen,
const unsigned char *adin, size_t adinlen)
{
- ctr_update(dctx, ent, entlen, adin, adinlen, NULL, 0);
+ if (ent == NULL)
+ return 0;
+ ctr_update(drbg, ent, entlen, adin, adinlen, NULL, 0);
return 1;
}
-int ctr_generate(DRBG_CTX *dctx,
+int ctr_generate(RAND_DRBG *drbg,
unsigned char *out, size_t outlen,
const unsigned char *adin, size_t adinlen)
{
- DRBG_CTR_CTX *cctx = &dctx->ctr;
+ RAND_DRBG_CTR *ctr = &drbg->ctr;
if (adin != NULL && adinlen != 0) {
- ctr_update(dctx, adin, adinlen, NULL, 0, NULL, 0);
+ ctr_update(drbg, adin, adinlen, NULL, 0, NULL, 0);
/* This means we reuse derived value */
- if (dctx->flags & RAND_DRBG_FLAG_CTR_USE_DF) {
+ if (drbg->flags & RAND_DRBG_FLAG_CTR_USE_DF) {
adin = NULL;
adinlen = 1;
}
}
for ( ; ; ) {
- inc_128(cctx);
+ inc_128(ctr);
if (outlen < 16) {
/* Use K as temp space as it will be updated */
- AES_encrypt(cctx->V, cctx->K, &cctx->ks);
- memcpy(out, cctx->K, outlen);
+ AES_encrypt(ctr->V, ctr->K, &ctr->ks);
+ memcpy(out, ctr->K, outlen);
break;
}
- AES_encrypt(cctx->V, out, &cctx->ks);
+ AES_encrypt(ctr->V, out, &ctr->ks);
out += 16;
outlen -= 16;
if (outlen == 0)
break;
}
- ctr_update(dctx, adin, adinlen, NULL, 0, NULL, 0);
+ ctr_update(drbg, adin, adinlen, NULL, 0, NULL, 0);
return 1;
}
-int ctr_uninstantiate(DRBG_CTX *dctx)
+int ctr_uninstantiate(RAND_DRBG *drbg)
{
- memset(&dctx->ctr, 0, sizeof(dctx->ctr));
+ memset(&drbg->ctr, 0, sizeof(drbg->ctr));
return 1;
}
-int ctr_init(DRBG_CTX *dctx)
+int ctr_init(RAND_DRBG *drbg)
{
- DRBG_CTR_CTX *cctx = &dctx->ctr;
+ RAND_DRBG_CTR *ctr = &drbg->ctr;
size_t keylen;
- switch (dctx->nid) {
+ switch (drbg->nid) {
default:
/* This can't happen, but silence the compiler warning. */
return -1;
break;
}
- cctx->keylen = keylen;
- dctx->strength = keylen * 8;
- dctx->blocklength = 16;
- dctx->seedlen = keylen + 16;
+ ctr->keylen = keylen;
+ drbg->strength = keylen * 8;
+ drbg->seedlen = keylen + 16;
- if (dctx->flags & RAND_DRBG_FLAG_CTR_USE_DF) {
+ if (drbg->flags & RAND_DRBG_FLAG_CTR_USE_DF) {
/* df initialisation */
static unsigned char df_key[32] = {
0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,
0x18,0x19,0x1a,0x1b,0x1c,0x1d,0x1e,0x1f
};
/* Set key schedule for df_key */
- AES_set_encrypt_key(df_key, dctx->strength, &cctx->df_ks);
-
- dctx->min_entropy = cctx->keylen;
- dctx->max_entropy = DRBG_MAX_LENGTH;
- dctx->min_nonce = dctx->min_entropy / 2;
- dctx->max_nonce = DRBG_MAX_LENGTH;
- dctx->max_pers = DRBG_MAX_LENGTH;
- dctx->max_adin = DRBG_MAX_LENGTH;
+ AES_set_encrypt_key(df_key, drbg->strength, &ctr->df_ks);
+
+ drbg->min_entropy = ctr->keylen;
+ drbg->max_entropy = DRBG_MAX_LENGTH;
+ drbg->min_nonce = drbg->min_entropy / 2;
+ drbg->max_nonce = DRBG_MAX_LENGTH;
+ drbg->max_pers = DRBG_MAX_LENGTH;
+ drbg->max_adin = DRBG_MAX_LENGTH;
} else {
- dctx->min_entropy = dctx->seedlen;
- dctx->max_entropy = dctx->seedlen;
+ drbg->min_entropy = drbg->seedlen;
+ drbg->max_entropy = drbg->seedlen;
/* Nonce not used */
- dctx->min_nonce = 0;
- dctx->max_nonce = 0;
- dctx->max_pers = dctx->seedlen;
- dctx->max_adin = dctx->seedlen;
+ drbg->min_nonce = 0;
+ drbg->max_nonce = 0;
+ drbg->max_pers = drbg->seedlen;
+ drbg->max_adin = drbg->seedlen;
}
- dctx->max_request = 1 << 16;
- dctx->reseed_interval = MAX_RESEED;
+ drbg->max_request = 1 << 16;
+ drbg->reseed_interval = MAX_RESEED;
return 1;
}
-
-
-/*
- * The following function tie the DRBG code into the RAND_METHOD
- */
-
-DRBG_CTX *RAND_DRBG_get_default(void)
-{
- if (!RUN_ONCE(&ossl_drbg_init, do_ossl_drbg_init))
- return NULL;
- return &ossl_drbg;
-}
-
-static int drbg_bytes(unsigned char *out, int count)
-{
- DRBG_CTX *dctx = RAND_DRBG_get_default();
- int ret = 0;
-
- CRYPTO_THREAD_write_lock(dctx->lock);
- do {
- size_t rcnt;
-
- if (count > (int)dctx->max_request)
- rcnt = dctx->max_request;
- else
- rcnt = count;
- ret = RAND_DRBG_generate(dctx, out, rcnt, 0, NULL, 0);
- if (!ret)
- goto err;
- out += rcnt;
- count -= rcnt;
- } while (count);
- ret = 1;
-err:
- CRYPTO_THREAD_unlock(dctx->lock);
- return ret;
-}
-
-static int drbg_status(void)
-{
- DRBG_CTX *dctx = RAND_DRBG_get_default();
- int ret;
-
- CRYPTO_THREAD_write_lock(dctx->lock);
- ret = dctx->status == DRBG_STATUS_READY ? 1 : 0;
- CRYPTO_THREAD_unlock(dctx->lock);
- return ret;
-}
-
-static void drbg_cleanup(void)
-{
- DRBG_CTX *dctx = RAND_DRBG_get_default();
-
- CRYPTO_THREAD_write_lock(dctx->lock);
- RAND_DRBG_uninstantiate(dctx);
- CRYPTO_THREAD_unlock(dctx->lock);
-}
-
-static const RAND_METHOD rand_drbg_meth =
-{
- NULL,
- drbg_bytes,
- drbg_cleanup,
- NULL,
- drbg_bytes,
- drbg_status
-};
-
-const RAND_METHOD *RAND_drbg(void)
-{
- return &rand_drbg_meth;
-}