[thirdparty/openssl.git] / crypto / rand / drbg_rand.c

/*
 * Copyright 2011-2017 The OpenSSL Project Authors. All Rights Reserved.
 *
 * Licensed under the OpenSSL license (the "License").  You may not use
 * this file except in compliance with the License.  You can obtain a copy
 * in the file LICENSE in the source distribution or at
 * https://www.openssl.org/source/license.html
 */

#include <stdlib.h>
#include <string.h>
#include <openssl/crypto.h>
#include <openssl/err.h>
#include <openssl/rand.h>
#include "rand_lcl.h"
#include "internal/thread_once.h"

/*
 * Mapping of NIST SP 800-90A DRBG to OpenSSL RAND_METHOD.
 */


/*
 * 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)
{
    int st = 1;

    ossl_drbg.lock = CRYPTO_THREAD_lock_new();
    st &= ossl_drbg.lock != NULL;
    st &= RAND_DRBG_set(&ossl_drbg, NID_aes_128_ctr, 0) == 1;
    return st;
}

void rand_drbg_cleanup(void)
{
    CRYPTO_THREAD_lock_free(ossl_drbg.lock);
}

static void inc_128(DRBG_CTR_CTX *cctx)
{
    int i;
    unsigned char c;
    unsigned char *p = &cctx->V[15];

    for (i = 0; i < 16; i++, p--) {
        c = *p;
        c++;
        *p = c;
        if (c != 0) {
            /* If we didn't wrap around, we're done. */
            break;
        }
    }
}

static void ctr_XOR(DRBG_CTR_CTX *cctx, const unsigned char *in, size_t inlen)
{
    size_t i, n;

    if (in == NULL || inlen == 0)
        return;

    /*
     * 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;
    for (i = 0; i < n; i++)
        cctx->K[i] ^= in[i];
    if (inlen <= cctx->keylen)
        return;

    n = inlen - cctx->keylen;
    if (n > 16) {
        /* Should never happen */
        n = 16;
    }
    for (i = 0; i < n; i++)
        cctx->V[i] ^= in[i + cctx->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,
                          const unsigned char *in)
{
    int i;

    for (i = 0; i < 16; i++)
        out[i] ^= in[i];
    AES_encrypt(out, out, &cctx->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)
{
    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);
}

/*
 * 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)
{
    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);
    }
}

/*
 * Process several blocks into BCC algorithm, some possibly partial
 */
static void ctr_BCC_update(DRBG_CTR_CTX *cctx,
                           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 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;
            inlen -= left;
            in += left;
        }
    }

    /* Process zero or more complete blocks */
    for (; inlen >= 16; in += 16, inlen -= 16) {
        ctr_BCC_blocks(cctx, 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;
    }
}

static void ctr_BCC_final(DRBG_CTR_CTX *cctx)
{
    if (cctx->bltmp_pos) {
        memset(cctx->bltmp + cctx->bltmp_pos, 0, 16 - cctx->bltmp_pos);
        ctr_BCC_blocks(cctx, cctx->bltmp);
    }
}

static void ctr_df(DRBG_CTR_CTX *cctx,
                   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;

    ctr_BCC_init(cctx);
    if (in1 == NULL)
        in1len = 0;
    if (in2 == NULL)
        in2len = 0;
    if (in3 == NULL)
        in3len = 0;
    inlen = in1len + in2len + in3len;
    /* Initialise L||N in temporary block */
    *p++ = (inlen >> 24) & 0xff;
    *p++ = (inlen >> 16) & 0xff;
    *p++ = (inlen >> 8) & 0xff;
    *p++ = inlen & 0xff;

    /* NB keylen is at most 32 bytes */
    *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);
    /* Set up key K */
    AES_set_encrypt_key(cctx->KX, cctx->keylen * 8, &cctx->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);
}

/*
 * 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.
 */
static void ctr_update(DRBG_CTX *dctx,
                       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;

    /* ks is already setup for correct key */
    inc_128(cctx);
    AES_encrypt(cctx->V, cctx->K, &cctx->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);
    }
    inc_128(cctx);
    AES_encrypt(cctx->V, cctx->V, &cctx->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 (dctx->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);
        /* If this a reuse input in1len != 0 */
        if (in1len)
            ctr_XOR(cctx, cctx->KX, dctx->seedlen);
    } else {
        ctr_XOR(cctx, in1, in1len);
        ctr_XOR(cctx, in2, in2len);
    }

    AES_set_encrypt_key(cctx->K, dctx->strength, &cctx->ks);
}

int ctr_instantiate(DRBG_CTX *dctx,
                    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;

    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);
    return 1;
}

int ctr_reseed(DRBG_CTX *dctx,
               const unsigned char *ent, size_t entlen,
               const unsigned char *adin, size_t adinlen)
{
    ctr_update(dctx, ent, entlen, adin, adinlen, NULL, 0);
    return 1;
}

int ctr_generate(DRBG_CTX *dctx,
                 unsigned char *out, size_t outlen,
                 const unsigned char *adin, size_t adinlen)
{
    DRBG_CTR_CTX *cctx = &dctx->ctr;

    if (adin != NULL && adinlen != 0) {
        ctr_update(dctx, adin, adinlen, NULL, 0, NULL, 0);
        /* This means we reuse derived value */
        if (dctx->flags & RAND_DRBG_FLAG_CTR_USE_DF) {
            adin = NULL;
            adinlen = 1;
        }
    } else {
        adinlen = 0;
    }

    for ( ; ; ) {
        inc_128(cctx);
        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);
            break;
        }
        AES_encrypt(cctx->V, out, &cctx->ks);
        out += 16;
        outlen -= 16;
        if (outlen == 0)
            break;
    }

    ctr_update(dctx, adin, adinlen, NULL, 0, NULL, 0);
    return 1;
}

int ctr_uninstantiate(DRBG_CTX *dctx)
{
    memset(&dctx->ctr, 0, sizeof(dctx->ctr));
    return 1;
}

int ctr_init(DRBG_CTX *dctx)
{
    DRBG_CTR_CTX *cctx = &dctx->ctr;
    size_t keylen;

    switch (dctx->nid) {
    default:
        /* This can't happen, but silence the compiler warning. */
        return -1;
    case NID_aes_128_ctr:
        keylen = 16;
        break;
    case NID_aes_192_ctr:
        keylen = 24;
        break;
    case NID_aes_256_ctr:
        keylen = 32;
        break;
    }

    cctx->keylen = keylen;
    dctx->strength = keylen * 8;
    dctx->blocklength = 16;
    dctx->seedlen = keylen + 16;

    if (dctx->flags & RAND_DRBG_FLAG_CTR_USE_DF) {
        /* df initialisation */
        static unsigned char df_key[32] = {
            0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,
            0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f,
            0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,
            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;
    } else {
        dctx->min_entropy = dctx->seedlen;
        dctx->max_entropy = dctx->seedlen;
        /* Nonce not used */
        dctx->min_nonce = 0;
        dctx->max_nonce = 0;
        dctx->max_pers = dctx->seedlen;
        dctx->max_adin = dctx->seedlen;
    }

    dctx->max_request = 1 << 16;
    dctx->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;
}
Commit	Line	Data
12fb8c3d RS	1	/*
	2	* Copyright 2011-2017 The OpenSSL Project Authors. All Rights Reserved.
	3	*
	4	* Licensed under the OpenSSL license (the "License"). You may not use
	5	* this file except in compliance with the License. You can obtain a copy
	6	* in the file LICENSE in the source distribution or at
	7	* https://www.openssl.org/source/license.html
	8	*/
	9
	10	#include <stdlib.h>
	11	#include <string.h>
	12	#include <openssl/crypto.h>
	13	#include <openssl/err.h>
	14	#include <openssl/rand.h>
	15	#include "rand_lcl.h"
	16	#include "internal/thread_once.h"
	17
	18	/*
	19	* Mapping of NIST SP 800-90A DRBG to OpenSSL RAND_METHOD.
	20	*/
	21
	22
	23	/*
	24	* The default global DRBG and its auto-init/auto-cleanup.
	25	*/
	26	static DRBG_CTX ossl_drbg;
	27
	28	static CRYPTO_ONCE ossl_drbg_init = CRYPTO_ONCE_STATIC_INIT;
	29
	30	DEFINE_RUN_ONCE_STATIC(do_ossl_drbg_init)
	31	{
8389ec4b RS	32	int st = 1;
8389ec4b RS	33
12fb8c3d	34	ossl_drbg.lock = CRYPTO_THREAD_lock_new();
8389ec4b RS	35	st &= ossl_drbg.lock != NULL;
	36	st &= RAND_DRBG_set(&ossl_drbg, NID_aes_128_ctr, 0) == 1;
	37	return st;
12fb8c3d RS	38	}
	39
	40	void rand_drbg_cleanup(void)
	41	{
	42	CRYPTO_THREAD_lock_free(ossl_drbg.lock);
	43	}
	44
	45	static void inc_128(DRBG_CTR_CTX *cctx)
	46	{
	47	int i;
	48	unsigned char c;
	49	unsigned char *p = &cctx->V[15];
	50
	51	for (i = 0; i < 16; i++, p--) {
	52	c = *p;
	53	c++;
	54	*p = c;
	55	if (c != 0) {
	56	/* If we didn't wrap around, we're done. */
	57	break;
	58	}
	59	}
	60	}
	61
	62	static void ctr_XOR(DRBG_CTR_CTX cctx, const unsigned char in, size_t inlen)
	63	{
	64	size_t i, n;
	65
	66	if (in == NULL \|\| inlen == 0)
	67	return;
	68
	69	/*
	70	* Any zero padding will have no effect on the result as we
	71	* are XORing. So just process however much input we have.
	72	*/
	73	n = inlen < cctx->keylen ? inlen : cctx->keylen;
	74	for (i = 0; i < n; i++)
	75	cctx->K[i] ^= in[i];
	76	if (inlen <= cctx->keylen)
	77	return;
	78
	79	n = inlen - cctx->keylen;
	80	if (n > 16) {
	81	/* Should never happen */
	82	n = 16;
	83	}
b8a437ff	84	for (i = 0; i < n; i++)
12fb8c3d RS	85	cctx->V[i] ^= in[i + cctx->keylen];
	86	}
	87
	88	/*
	89	* Process a complete block using BCC algorithm of SP 800-90A 10.3.3
	90	*/
	91	static void ctr_BCC_block(DRBG_CTR_CTX cctx, unsigned char out,
	92	const unsigned char *in)
	93	{
	94	int i;
	95
	96	for (i = 0; i < 16; i++)
	97	out[i] ^= in[i];
	98	AES_encrypt(out, out, &cctx->df_ks);
	99	}
	100
	101
	102	/*
	103	* Handle several BCC operations for as much data as we need for K and X
	104	*/
	105	static void ctr_BCC_blocks(DRBG_CTR_CTX cctx, const unsigned char in)
	106	{
	107	ctr_BCC_block(cctx, cctx->KX, in);
	108	ctr_BCC_block(cctx, cctx->KX + 16, in);
	109	if (cctx->keylen != 16)
	110	ctr_BCC_block(cctx, cctx->KX + 32, in);
	111	}
	112
	113	/*
	114	* Initialise BCC blocks: these have the value 0,1,2 in leftmost positions:
	115	* see 10.3.1 stage 7.
	116	*/
	117	static void ctr_BCC_init(DRBG_CTR_CTX *cctx)
	118	{
	119	memset(cctx->KX, 0, 48);
	120	memset(cctx->bltmp, 0, 16);
	121	ctr_BCC_block(cctx, cctx->KX, cctx->bltmp);
	122	cctx->bltmp[3] = 1;
	123	ctr_BCC_block(cctx, cctx->KX + 16, cctx->bltmp);
	124	if (cctx->keylen != 16) {
	125	cctx->bltmp[3] = 2;
	126	ctr_BCC_block(cctx, cctx->KX + 32, cctx->bltmp);
	127	}
	128	}
	129
	130	/*
	131	* Process several blocks into BCC algorithm, some possibly partial
	132	*/
	133	static void ctr_BCC_update(DRBG_CTR_CTX *cctx,
	134	const unsigned char *in, size_t inlen)
	135	{
	136	if (in == NULL \|\| inlen == 0)
	137	return;
	138
	139	/* If we have partial block handle it first */
	140	if (cctx->bltmp_pos) {
	141	size_t left = 16 - cctx->bltmp_pos;
	142
	143	/* If we now have a complete block process it */
	144	if (inlen >= left) {
	145	memcpy(cctx->bltmp + cctx->bltmp_pos, in, left);
	146	ctr_BCC_blocks(cctx, cctx->bltmp);
	147	cctx->bltmp_pos = 0;
	148	inlen -= left;
149	in += left;
150	}
151	}
152
153	/* Process zero or more complete blocks */
154	for (; inlen >= 16; in += 16, inlen -= 16) {
155	ctr_BCC_blocks(cctx, in);
156	}
157
158	/* Copy any remaining partial block to the temporary buffer */
159	if (inlen > 0) {
160	memcpy(cctx->bltmp + cctx->bltmp_pos, in, inlen);
161	cctx->bltmp_pos += inlen;
162	}
163	}
164
165	static void ctr_BCC_final(DRBG_CTR_CTX *cctx)
166	{
167	if (cctx->bltmp_pos) {
168	memset(cctx->bltmp + cctx->bltmp_pos, 0, 16 - cctx->bltmp_pos);
169	ctr_BCC_blocks(cctx, cctx->bltmp);
170	}
171	}
172
173	static void ctr_df(DRBG_CTR_CTX *cctx,
174	const unsigned char *in1, size_t in1len,
175	const unsigned char *in2, size_t in2len,
176	const unsigned char *in3, size_t in3len)
177	{
178	static unsigned char c80 = 0x80;
179	size_t inlen;
180	unsigned char *p = cctx->bltmp;
181
182	ctr_BCC_init(cctx);
183	if (in1 == NULL)
184	in1len = 0;
185	if (in2 == NULL)
186	in2len = 0;
187	if (in3 == NULL)
188	in3len = 0;
189	inlen = in1len + in2len + in3len;
190	/* Initialise L\|\|N in temporary block */
191	*p++ = (inlen >> 24) & 0xff;
192	*p++ = (inlen >> 16) & 0xff;
193	*p++ = (inlen >> 8) & 0xff;
194	*p++ = inlen & 0xff;
195
196	/* NB keylen is at most 32 bytes */
197	*p++ = 0;
198	*p++ = 0;
199	*p++ = 0;
200	*p = (unsigned char)((cctx->keylen + 16) & 0xff);
201	cctx->bltmp_pos = 8;
202	ctr_BCC_update(cctx, in1, in1len);
203	ctr_BCC_update(cctx, in2, in2len);
204	ctr_BCC_update(cctx, in3, in3len);
205	ctr_BCC_update(cctx, &c80, 1);
206	ctr_BCC_final(cctx);
207	/* Set up key K */
208	AES_set_encrypt_key(cctx->KX, cctx->keylen * 8, &cctx->df_kxks);
209	/* X follows key K */
210	AES_encrypt(cctx->KX + cctx->keylen, cctx->KX, &cctx->df_kxks);
211	AES_encrypt(cctx->KX, cctx->KX + 16, &cctx->df_kxks);
212	if (cctx->keylen != 16)
213	AES_encrypt(cctx->KX + 16, cctx->KX + 32, &cctx->df_kxks);
214	}
215
216	/*
217	* NB the no-df Update in SP800-90A specifies a constant input length
218	* of seedlen, however other uses of this algorithm pad the input with
219	* zeroes if necessary and have up to two parameters XORed together,
220	* handle both cases in this function instead.
221	*/
222	static void ctr_update(DRBG_CTX *dctx,
223	const unsigned char *in1, size_t in1len,
224	const unsigned char *in2, size_t in2len,
225	const unsigned char *nonce, size_t noncelen)
226	{
227	DRBG_CTR_CTX *cctx = &dctx->ctr;
228
229	/* ks is already setup for correct key */
230	inc_128(cctx);
231	AES_encrypt(cctx->V, cctx->K, &cctx->ks);
232
233	/* If keylen longer than 128 bits need extra encrypt */
234	if (cctx->keylen != 16) {
235	inc_128(cctx);
236	AES_encrypt(cctx->V, cctx->K + 16, &cctx->ks);
237	}
238	inc_128(cctx);
239	AES_encrypt(cctx->V, cctx->V, &cctx->ks);
240
241	/* If 192 bit key part of V is on end of K */
242	if (cctx->keylen == 24) {
243	memcpy(cctx->V + 8, cctx->V, 8);
244	memcpy(cctx->V, cctx->K + 24, 8);
245	}
246
247	if (dctx->flags & RAND_DRBG_FLAG_CTR_USE_DF) {
248	/* If no input reuse existing derived value */
249	if (in1 != NULL \|\| nonce != NULL \|\| in2 != NULL)
250	ctr_df(cctx, in1, in1len, nonce, noncelen, in2, in2len);
251	/* If this a reuse input in1len != 0 */
252	if (in1len)
253	ctr_XOR(cctx, cctx->KX, dctx->seedlen);
254	} else {
255	ctr_XOR(cctx, in1, in1len);
256	ctr_XOR(cctx, in2, in2len);
257	}
258
259	AES_set_encrypt_key(cctx->K, dctx->strength, &cctx->ks);
260	}
261
262	int ctr_instantiate(DRBG_CTX *dctx,
263	const unsigned char *ent, size_t entlen,
264	const unsigned char *nonce, size_t noncelen,
265	const unsigned char *pers, size_t perslen)
266	{
267	DRBG_CTR_CTX *cctx = &dctx->ctr;
268
269	memset(cctx->K, 0, sizeof(cctx->K));
270	memset(cctx->V, 0, sizeof(cctx->V));
271	AES_set_encrypt_key(cctx->K, dctx->strength, &cctx->ks);
272	ctr_update(dctx, ent, entlen, pers, perslen, nonce, noncelen);
273	return 1;
274	}
275
276	int ctr_reseed(DRBG_CTX *dctx,
277	const unsigned char *ent, size_t entlen,
278	const unsigned char *adin, size_t adinlen)
279	{
280	ctr_update(dctx, ent, entlen, adin, adinlen, NULL, 0);
281	return 1;
282	}
283
284	int ctr_generate(DRBG_CTX *dctx,
285	unsigned char *out, size_t outlen,
286	const unsigned char *adin, size_t adinlen)
287	{
288	DRBG_CTR_CTX *cctx = &dctx->ctr;
289
290	if (adin != NULL && adinlen != 0) {
291	ctr_update(dctx, adin, adinlen, NULL, 0, NULL, 0);
292	/* This means we reuse derived value */
293	if (dctx->flags & RAND_DRBG_FLAG_CTR_USE_DF) {
294	adin = NULL;
295	adinlen = 1;
296	}
297	} else {
298	adinlen = 0;
299	}
300
301	for ( ; ; ) {
302	inc_128(cctx);
303	if (outlen < 16) {
304	/* Use K as temp space as it will be updated */
305	AES_encrypt(cctx->V, cctx->K, &cctx->ks);
306	memcpy(out, cctx->K, outlen);
307	break;
308	}
309	AES_encrypt(cctx->V, out, &cctx->ks);
310	out += 16;
311	outlen -= 16;
312	if (outlen == 0)
313	break;
314	}
315
316	ctr_update(dctx, adin, adinlen, NULL, 0, NULL, 0);
317	return 1;
318	}
319
320	int ctr_uninstantiate(DRBG_CTX *dctx)
321	{
322	memset(&dctx->ctr, 0, sizeof(dctx->ctr));
323	return 1;
324	}
325
326	int ctr_init(DRBG_CTX *dctx)
327	{
328	DRBG_CTR_CTX *cctx = &dctx->ctr;
329	size_t keylen;
330
331	switch (dctx->nid) {
332	default:
333	/* This can't happen, but silence the compiler warning. */
334	return -1;
335	case NID_aes_128_ctr:
336	keylen = 16;
337	break;
338	case NID_aes_192_ctr:
339	keylen = 24;
340	break;
341	case NID_aes_256_ctr:
342	keylen = 32;
343	break;
344	}
345
346	cctx->keylen = keylen;
347	dctx->strength = keylen * 8;
348	dctx->blocklength = 16;
349	dctx->seedlen = keylen + 16;
350
351	if (dctx->flags & RAND_DRBG_FLAG_CTR_USE_DF) {
352	/* df initialisation */
353	static unsigned char df_key[32] = {
354	0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,
355	0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f,
356	0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,
357	0x18,0x19,0x1a,0x1b,0x1c,0x1d,0x1e,0x1f
358	};
359	/* Set key schedule for df_key */
360	AES_set_encrypt_key(df_key, dctx->strength, &cctx->df_ks);
361
362	dctx->min_entropy = cctx->keylen;
363	dctx->max_entropy = DRBG_MAX_LENGTH;
364	dctx->min_nonce = dctx->min_entropy / 2;
365	dctx->max_nonce = DRBG_MAX_LENGTH;
366	dctx->max_pers = DRBG_MAX_LENGTH;
367	dctx->max_adin = DRBG_MAX_LENGTH;
368	} else {
369	dctx->min_entropy = dctx->seedlen;
370	dctx->max_entropy = dctx->seedlen;
371	/* Nonce not used */
372	dctx->min_nonce = 0;
373	dctx->max_nonce = 0;
374	dctx->max_pers = dctx->seedlen;
375	dctx->max_adin = dctx->seedlen;
376	}
377
378	dctx->max_request = 1 << 16;
4c75ee85	379	dctx->reseed_interval = MAX_RESEED;
12fb8c3d RS	380	return 1;
	381	}
	382
	383
	384	/*
	385	* The following function tie the DRBG code into the RAND_METHOD
	386	*/
	387
	388	DRBG_CTX *RAND_DRBG_get_default(void)
	389	{
	390	if (!RUN_ONCE(&ossl_drbg_init, do_ossl_drbg_init))
	391	return NULL;
	392	return &ossl_drbg;
	393	}
	394
	395	static int drbg_bytes(unsigned char *out, int count)
	396	{
	397	DRBG_CTX *dctx = RAND_DRBG_get_default();
	398	int ret = 0;
	399
	400	CRYPTO_THREAD_write_lock(dctx->lock);
	401	do {
	402	size_t rcnt;
	403
	404	if (count > (int)dctx->max_request)
	405	rcnt = dctx->max_request;
	406	else
	407	rcnt = count;
	408	ret = RAND_DRBG_generate(dctx, out, rcnt, 0, NULL, 0);
	409	if (!ret)
	410	goto err;
	411	out += rcnt;
	412	count -= rcnt;
	413	} while (count);
	414	ret = 1;
	415	err:
	416	CRYPTO_THREAD_unlock(dctx->lock);
	417	return ret;
	418	}
	419
	420	static int drbg_status(void)
	421	{
	422	DRBG_CTX *dctx = RAND_DRBG_get_default();
	423	int ret;
	424
	425	CRYPTO_THREAD_write_lock(dctx->lock);
	426	ret = dctx->status == DRBG_STATUS_READY ? 1 : 0;
	427	CRYPTO_THREAD_unlock(dctx->lock);
	428	return ret;
	429	}
	430
	431	static void drbg_cleanup(void)
	432	{
	433	DRBG_CTX *dctx = RAND_DRBG_get_default();
	434
	435	CRYPTO_THREAD_write_lock(dctx->lock);
	436	RAND_DRBG_uninstantiate(dctx);
	437	CRYPTO_THREAD_unlock(dctx->lock);
	438	}
	439
	440	static const RAND_METHOD rand_drbg_meth =
	441	{
	442	NULL,
	443	drbg_bytes,
444	drbg_cleanup,
445	NULL,
446	drbg_bytes,
447	drbg_status
448	};
449
450	const RAND_METHOD *RAND_drbg(void)
451	{
452	return &rand_drbg_meth;
453	}