diff options
Diffstat (limited to 'fips/rand/fips_drbg_ec.c')
| -rw-r--r-- | fips/rand/fips_drbg_ec.c | 542 |
1 files changed, 542 insertions, 0 deletions
diff --git a/fips/rand/fips_drbg_ec.c b/fips/rand/fips_drbg_ec.c new file mode 100644 index 0000000000..6be6534ce7 --- /dev/null +++ b/fips/rand/fips_drbg_ec.c @@ -0,0 +1,542 @@ +/* fips/rand/fips_drbg_ec.c */ +/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL + * project. + */ +/* ==================================================================== + * Copyright (c) 2011 The OpenSSL Project. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * 3. All advertising materials mentioning features or use of this + * software must display the following acknowledgment: + * "This product includes software developed by the OpenSSL Project + * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" + * + * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to + * endorse or promote products derived from this software without + * prior written permission. For written permission, please contact + * licensing@OpenSSL.org. + * + * 5. Products derived from this software may not be called "OpenSSL" + * nor may "OpenSSL" appear in their names without prior written + * permission of the OpenSSL Project. + * + * 6. Redistributions of any form whatsoever must retain the following + * acknowledgment: + * "This product includes software developed by the OpenSSL Project + * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" + * + * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY + * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR + * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED + * OF THE POSSIBILITY OF SUCH DAMAGE. + * ==================================================================== + */ + +#define OPENSSL_FIPSAPI + +#include <stdlib.h> +#include <string.h> +#include <openssl/crypto.h> +#include <openssl/fips.h> +#include <openssl/fips_rand.h> +#include <openssl/bn.h> +#include "fips_rand_lcl.h" + +/*#define EC_DRBG_TRACE*/ + +#ifdef EC_DRBG_TRACE +static void hexprint(FILE *out, const unsigned char *buf, int buflen) + { + int i; + fprintf(out, "\t"); + for (i = 0; i < buflen; i++) + fprintf(out, "%02X", buf[i]); + fprintf(out, "\n"); + } +static void bnprint(FILE *out, const char *name, const BIGNUM *b) + { + unsigned char *tmp; + int len; + len = BN_num_bytes(b); + tmp = OPENSSL_malloc(len); + BN_bn2bin(b, tmp); + fprintf(out, "%s\n", name); + hexprint(out, tmp, len); + OPENSSL_free(tmp); + } +#if 0 +static void ecprint(FILE *out, EC_GROUP *grp, EC_POINT *pt) + { + BIGNUM *x, *y; + x = BN_new(); + y = BN_new(); + EC_POINT_get_affine_coordinates_GFp(grp, pt, x, y, NULL); + bnprint(out, "\tPoint X: ", x); + bnprint(out, "\tPoint Y: ", y); + BN_free(x); + BN_free(y); + } +#endif +#endif + +/* This is Hash_df from SP 800-90 10.4.1 */ + +static int hash_df(DRBG_CTX *dctx, unsigned char *out, + const unsigned char *in1, size_t in1len, + const unsigned char *in2, size_t in2len, + const unsigned char *in3, size_t in3len) + { + DRBG_EC_CTX *ectx = &dctx->d.ec; + EVP_MD_CTX *mctx = &ectx->mctx; + unsigned char *vtmp = ectx->vtmp; + unsigned char tmp[6]; + size_t mdlen = M_EVP_MD_size(ectx->md); + /* Standard only ever needs seedlen bytes which is always less than + * maximum permitted so no need to check length. + */ + size_t outlen = dctx->seedlen; + size_t nbits = (outlen << 3) - ectx->exbits; + tmp[0] = 1; + tmp[1] = (nbits >> 24) & 0xff; + tmp[2] = (nbits >> 16) & 0xff; + tmp[3] = (nbits >> 8) & 0xff; + tmp[4] = nbits & 0xff; + if (!in1) + { + tmp[5] = (unsigned char)in1len; + in1 = tmp + 5; + in1len = 1; + } + for (;;) + { + if (!FIPS_digestinit(mctx, ectx->md)) + return 0; + if (!FIPS_digestupdate(mctx, tmp, 5)) + return 0; + if (in1 && !FIPS_digestupdate(mctx, in1, in1len)) + return 0; + if (in2 && !FIPS_digestupdate(mctx, in2, in2len)) + return 0; + if (in3 && !FIPS_digestupdate(mctx, in3, in3len)) + return 0; + if (outlen < mdlen) + { + if (!FIPS_digestfinal(mctx, vtmp, NULL)) + return 0; + memcpy(out, vtmp, outlen); + OPENSSL_cleanse(vtmp, mdlen); + return 1; + } + else if(!FIPS_digestfinal(mctx, out, NULL)) + return 0; + + outlen -= mdlen; + if (outlen == 0) + return 1; + tmp[0]++; + out += mdlen; + } + } + +static int bn2binpad(unsigned char *to, size_t tolen, BIGNUM *b) + { + size_t blen; + blen = BN_num_bytes(b); + /* If BIGNUM length greater than buffer, mask to get rightmost + * bytes. NB: modifies b but this doesn't matter for our purposes. + */ + if (blen > tolen) + { + BN_mask_bits(b, tolen << 3); + /* Update length because mask operation might create leading + * zeroes. + */ + blen = BN_num_bytes(b); + } + /* If b length smaller than buffer pad with zeroes */ + if (blen < tolen) + { + memset(to, 0, tolen - blen); + to += tolen - blen; + } + + /* This call cannot fail */ + BN_bn2bin(b, to); + return 1; + } +/* Convert buffer to a BIGNUM discarding extra bits if necessary */ +static int bin2bnbits(DRBG_CTX *dctx, BIGNUM *r, const unsigned char *buf) + { + DRBG_EC_CTX *ectx = &dctx->d.ec; + if (!BN_bin2bn(buf, dctx->seedlen, r)) + return 0; + /* If we have extra bits right shift off the end of r */ + if (ectx->exbits) + { + if (!BN_rshift(r, r, ectx->exbits)) + return 0; + } + return 1; + } + +/* Calculate r = phi(s * P) or r= phi(s * Q) */ + +static int drbg_ec_mul(DRBG_EC_CTX *ectx, BIGNUM *r, const BIGNUM *s, int use_q) + { + if (use_q) + { + if (!EC_POINT_mul(ectx->curve, ectx->ptmp, + NULL, ectx->Q, s, ectx->bctx)) + return 0; + } + else + { + if (!EC_POINT_mul(ectx->curve, ectx->ptmp, + s, NULL, NULL, ectx->bctx)) + return 0; + } + /* Get x coordinate of result */ + if (!EC_POINT_get_affine_coordinates_GFp(ectx->curve, ectx->ptmp, r, + NULL, ectx->bctx)) + return 0; + return 1; + } + +static int drbg_ec_instantiate(DRBG_CTX *dctx, + const unsigned char *ent, size_t ent_len, + const unsigned char *nonce, size_t nonce_len, + const unsigned char *pstr, size_t pstr_len) + { + DRBG_EC_CTX *ectx = &dctx->d.ec; + if (!hash_df(dctx, ectx->sbuf, + ent, ent_len, nonce, nonce_len, pstr, pstr_len)) + return 0; + if (!bin2bnbits(dctx, ectx->s, ectx->sbuf)) + return 0; + return 1; + } + + +static int drbg_ec_reseed(DRBG_CTX *dctx, + const unsigned char *ent, size_t ent_len, + const unsigned char *adin, size_t adin_len) + { + DRBG_EC_CTX *ectx = &dctx->d.ec; + /* Convert s value to a binary buffer. Save it to tbuf as we are + * about to overwrite it. + */ + if (ectx->exbits) + BN_lshift(ectx->s, ectx->s, ectx->exbits); + bn2binpad(ectx->tbuf, dctx->seedlen, ectx->s); + if (!hash_df(dctx, ectx->sbuf, ectx->tbuf, dctx->seedlen, + ent, ent_len, adin, adin_len)) + return 0; + if (!bin2bnbits(dctx, ectx->s, ectx->sbuf)) + return 0; + dctx->reseed_counter = 0; + return 1; + } + +static int drbg_ec_generate(DRBG_CTX *dctx, + unsigned char *out, size_t outlen, + const unsigned char *adin, size_t adin_len) + { + DRBG_EC_CTX *ectx = &dctx->d.ec; + BIGNUM *t, *r; + BIGNUM *s = ectx->s; + /* special case: check reseed interval */ + if (out == NULL) + { + size_t nb = (outlen + dctx->blocklength - 1)/dctx->blocklength; + if (dctx->reseed_counter + nb > dctx->reseed_interval) + dctx->status = DRBG_STATUS_RESEED; + return 1; + } + + BN_CTX_start(ectx->bctx); + r = BN_CTX_get(ectx->bctx); + if (!r) + goto err; + if (adin && adin_len) + { + size_t i; + t = BN_CTX_get(ectx->bctx); + if (!t) + goto err; + /* Convert s to buffer */ + if (ectx->exbits) + BN_lshift(s, s, ectx->exbits); + bn2binpad(ectx->sbuf, dctx->seedlen, s); + /* Step 2 */ + if (!hash_df(dctx, ectx->tbuf, adin, adin_len, + NULL, 0, NULL, 0)) + goto err; + /* Step 5 */ + for (i = 0; i < dctx->seedlen; i++) + ectx->tbuf[i] ^= ectx->sbuf[i]; + if (!bin2bnbits(dctx, t, ectx->tbuf)) + return 0; + } + else + /* Note if no additional input the algorithm never + * needs separate values for t and s. + */ + t = s; + +#ifdef EC_DRBG_TRACE + bnprint(stderr, "s at start of generate: ", s); +#endif + + for (;;) + { + /* Step #6, calculate s = t * P */ + if (!drbg_ec_mul(ectx, s, t, 0)) + goto err; +#ifdef EC_DRBG_TRACE + bnprint(stderr, "s in generate: ", ectx->s); +#endif + /* Step #7, calculate r = s * Q */ + if (!drbg_ec_mul(ectx, r, s, 1)) + goto err; +#ifdef EC_DRBG_TRACE + bnprint(stderr, "r in generate is: ", r); +#endif + dctx->reseed_counter++; + /* Get rightmost bits of r to output buffer */ + + if (!(dctx->xflags & DRBG_FLAG_TEST) && !dctx->lb_valid) + { + if (!bn2binpad(dctx->lb, dctx->blocklength, r)) + goto err; + dctx->lb_valid = 1; + continue; + } + if (outlen < dctx->blocklength) + { + if (!bn2binpad(ectx->vtmp, dctx->blocklength, r)) + goto err; + if (!fips_drbg_cprng_test(dctx, ectx->vtmp)) + goto err; + memcpy(out, ectx->vtmp, outlen); + break; + } + else + { + if (!bn2binpad(out, dctx->blocklength, r)) + goto err; + if (!fips_drbg_cprng_test(dctx, out)) + goto err; + } + outlen -= dctx->blocklength; + if (!outlen) + break; + out += dctx->blocklength; + /* Step #5 after first pass */ + t = s; +#ifdef EC_DRBG_TRACE + fprintf(stderr, "Random bits written:\n"); + hexprint(stderr, out, dctx->blocklength); +#endif + } + if (!drbg_ec_mul(ectx, ectx->s, ectx->s, 0)) + return 0; +#ifdef EC_DRBG_TRACE + bnprint(stderr, "s after generate is: ", s); +#endif + BN_CTX_end(ectx->bctx); + return 1; + err: + BN_CTX_end(ectx->bctx); + return 0; + } + +static int drbg_ec_uninstantiate(DRBG_CTX *dctx) + { + DRBG_EC_CTX *ectx = &dctx->d.ec; + EVP_MD_CTX_cleanup(&ectx->mctx); + EC_GROUP_free(ectx->curve); + EC_POINT_free(ectx->Q); + EC_POINT_free(ectx->ptmp); + BN_clear_free(ectx->s); + BN_CTX_free(ectx->bctx); + OPENSSL_cleanse(&dctx->d.ec, sizeof(DRBG_EC_CTX)); + return 1; + } + +/* Q points from SP 800-90 A.1, P is generator */ + +__fips_constseg +static const unsigned char p_256_qx[] = { + 0xc9,0x74,0x45,0xf4,0x5c,0xde,0xf9,0xf0,0xd3,0xe0,0x5e,0x1e, + 0x58,0x5f,0xc2,0x97,0x23,0x5b,0x82,0xb5,0xbe,0x8f,0xf3,0xef, + 0xca,0x67,0xc5,0x98,0x52,0x01,0x81,0x92 +}; +__fips_constseg +static const unsigned char p_256_qy[] = { + 0xb2,0x8e,0xf5,0x57,0xba,0x31,0xdf,0xcb,0xdd,0x21,0xac,0x46, + 0xe2,0xa9,0x1e,0x3c,0x30,0x4f,0x44,0xcb,0x87,0x05,0x8a,0xda, + 0x2c,0xb8,0x15,0x15,0x1e,0x61,0x00,0x46 +}; + +__fips_constseg +static const unsigned char p_384_qx[] = { + 0x8e,0x72,0x2d,0xe3,0x12,0x5b,0xdd,0xb0,0x55,0x80,0x16,0x4b, + 0xfe,0x20,0xb8,0xb4,0x32,0x21,0x6a,0x62,0x92,0x6c,0x57,0x50, + 0x2c,0xee,0xde,0x31,0xc4,0x78,0x16,0xed,0xd1,0xe8,0x97,0x69, + 0x12,0x41,0x79,0xd0,0xb6,0x95,0x10,0x64,0x28,0x81,0x50,0x65 +}; +__fips_constseg +static const unsigned char p_384_qy[] = { + 0x02,0x3b,0x16,0x60,0xdd,0x70,0x1d,0x08,0x39,0xfd,0x45,0xee, + 0xc3,0x6f,0x9e,0xe7,0xb3,0x2e,0x13,0xb3,0x15,0xdc,0x02,0x61, + 0x0a,0xa1,0xb6,0x36,0xe3,0x46,0xdf,0x67,0x1f,0x79,0x0f,0x84, + 0xc5,0xe0,0x9b,0x05,0x67,0x4d,0xbb,0x7e,0x45,0xc8,0x03,0xdd +}; + +__fips_constseg +static const unsigned char p_521_qx[] = { + 0x01,0xb9,0xfa,0x3e,0x51,0x8d,0x68,0x3c,0x6b,0x65,0x76,0x36, + 0x94,0xac,0x8e,0xfb,0xae,0xc6,0xfa,0xb4,0x4f,0x22,0x76,0x17, + 0x1a,0x42,0x72,0x65,0x07,0xdd,0x08,0xad,0xd4,0xc3,0xb3,0xf4, + 0xc1,0xeb,0xc5,0xb1,0x22,0x2d,0xdb,0xa0,0x77,0xf7,0x22,0x94, + 0x3b,0x24,0xc3,0xed,0xfa,0x0f,0x85,0xfe,0x24,0xd0,0xc8,0xc0, + 0x15,0x91,0xf0,0xbe,0x6f,0x63 +}; +__fips_constseg +static const unsigned char p_521_qy[] = { + 0x01,0xf3,0xbd,0xba,0x58,0x52,0x95,0xd9,0xa1,0x11,0x0d,0x1d, + 0xf1,0xf9,0x43,0x0e,0xf8,0x44,0x2c,0x50,0x18,0x97,0x6f,0xf3, + 0x43,0x7e,0xf9,0x1b,0x81,0xdc,0x0b,0x81,0x32,0xc8,0xd5,0xc3, + 0x9c,0x32,0xd0,0xe0,0x04,0xa3,0x09,0x2b,0x7d,0x32,0x7c,0x0e, + 0x7a,0x4d,0x26,0xd2,0xc7,0xb6,0x9b,0x58,0xf9,0x06,0x66,0x52, + 0x91,0x1e,0x45,0x77,0x79,0xde +}; + +int fips_drbg_ec_init(DRBG_CTX *dctx) + { + const EVP_MD *md; + const unsigned char *Q_x, *Q_y; + BIGNUM *x, *y; + size_t ptlen; + int md_nid = dctx->type & 0xffff; + int curve_nid = dctx->type >> 16; + DRBG_EC_CTX *ectx = &dctx->d.ec; + md = FIPS_get_digestbynid(md_nid); + if (!md) + return -2; + + /* These are taken from SP 800-90 10.3.1 table 4 */ + switch (curve_nid) + { + case NID_X9_62_prime256v1: + dctx->strength = 128; + dctx->seedlen = 32; + dctx->blocklength = 30; + ectx->exbits = 0; + Q_x = p_256_qx; + Q_y = p_256_qy; + ptlen = sizeof(p_256_qx); + break; + + case NID_secp384r1: + if (md_nid == NID_sha1) + return -2; + dctx->strength = 192; + dctx->seedlen = 48; + dctx->blocklength = 46; + ectx->exbits = 0; + Q_x = p_384_qx; + Q_y = p_384_qy; + ptlen = sizeof(p_384_qx); + break; + + case NID_secp521r1: + if (md_nid == NID_sha1 || md_nid == NID_sha224) + return -2; + dctx->strength = 256; + dctx->seedlen = 66; + dctx->blocklength = 63; + ectx->exbits = 7; + Q_x = p_521_qx; + Q_y = p_521_qy; + ptlen = sizeof(p_521_qx); + break; + + default: + return -2; + } + + dctx->iflags |= DRBG_CUSTOM_RESEED; + dctx->reseed_counter = 0; + dctx->instantiate = drbg_ec_instantiate; + dctx->reseed = drbg_ec_reseed; + dctx->generate = drbg_ec_generate; + dctx->uninstantiate = drbg_ec_uninstantiate; + + ectx->md = md; + EVP_MD_CTX_init(&ectx->mctx); + + dctx->min_entropy = dctx->strength / 8; + dctx->max_entropy = 2 << 10; + + dctx->min_nonce = dctx->min_entropy / 2; + dctx->max_nonce = 2 << 10; + + dctx->max_pers = 2 << 10; + dctx->max_adin = 2 << 10; + + dctx->reseed_interval = 1<<24; + dctx->max_request = dctx->reseed_interval * dctx->blocklength; + + /* Setup internal structures */ + ectx->bctx = BN_CTX_new(); + if (!ectx->bctx) + return 0; + BN_CTX_start(ectx->bctx); + + ectx->s = BN_new(); + + ectx->curve = EC_GROUP_new_by_curve_name(curve_nid); + + ectx->Q = EC_POINT_new(ectx->curve); + ectx->ptmp = EC_POINT_new(ectx->curve); + + x = BN_CTX_get(ectx->bctx); + y = BN_CTX_get(ectx->bctx); + + if (!ectx->s || !ectx->curve || !ectx->Q || !y) + goto err; + + if (!BN_bin2bn(Q_x, ptlen, x) || !BN_bin2bn(Q_y, ptlen, y)) + goto err; + if (!EC_POINT_set_affine_coordinates_GFp(ectx->curve, ectx->Q, + x, y, ectx->bctx)) + goto err; + + BN_CTX_end(ectx->bctx); + + return 1; + err: + BN_CTX_end(ectx->bctx); + drbg_ec_uninstantiate(dctx); + return 0; + } |