/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) * All rights reserved. * * This package is an SSL implementation written * by Eric Young (eay@cryptsoft.com). * The implementation was written so as to conform with Netscapes SSL. * * This library is free for commercial and non-commercial use as long as * the following conditions are aheared to. The following conditions * apply to all code found in this distribution, be it the RC4, RSA, * lhash, DES, etc., code; not just the SSL code. The SSL documentation * included with this distribution is covered by the same copyright terms * except that the holder is Tim Hudson (tjh@cryptsoft.com). * * Copyright remains Eric Young's, and as such any Copyright notices in * the code are not to be removed. * If this package is used in a product, Eric Young should be given attribution * as the author of the parts of the library used. * This can be in the form of a textual message at program startup or * in documentation (online or textual) provided with the package. * * 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 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 acknowledgement: * "This product includes cryptographic software written by * Eric Young (eay@cryptsoft.com)" * The word 'cryptographic' can be left out if the rouines from the library * being used are not cryptographic related :-). * 4. If you include any Windows specific code (or a derivative thereof) from * the apps directory (application code) you must include an acknowledgement: * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" * * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND * ANY EXPRESS 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 AUTHOR OR 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. * * The licence and distribution terms for any publically available version or * derivative of this code cannot be changed. i.e. this code cannot simply be * copied and put under another distribution licence * [including the GNU Public Licence.] */ /* ==================================================================== * Copyright (c) 1998-2006 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 * openssl-core@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. * ==================================================================== * * This product includes cryptographic software written by Eric Young * (eay@cryptsoft.com). This product includes software written by Tim * Hudson (tjh@cryptsoft.com). * */ #include "internal/cryptlib.h" #include "internal/bn_int.h" #include #include "rsa_locl.h" #ifndef RSA_NULL static int rsa_ossl_public_encrypt(int flen, const unsigned char *from, unsigned char *to, RSA *rsa, int padding); static int rsa_ossl_private_encrypt(int flen, const unsigned char *from, unsigned char *to, RSA *rsa, int padding); static int rsa_ossl_public_decrypt(int flen, const unsigned char *from, unsigned char *to, RSA *rsa, int padding); static int rsa_ossl_private_decrypt(int flen, const unsigned char *from, unsigned char *to, RSA *rsa, int padding); static int rsa_ossl_mod_exp(BIGNUM *r0, const BIGNUM *i, RSA *rsa, BN_CTX *ctx); static int rsa_ossl_init(RSA *rsa); static int rsa_ossl_finish(RSA *rsa); static RSA_METHOD rsa_pkcs1_ossl_meth = { "OpenSSL PKCS#1 RSA (from Eric Young)", rsa_ossl_public_encrypt, rsa_ossl_public_decrypt, /* signature verification */ rsa_ossl_private_encrypt, /* signing */ rsa_ossl_private_decrypt, rsa_ossl_mod_exp, BN_mod_exp_mont, /* XXX probably we should not use Montgomery * if e == 3 */ rsa_ossl_init, rsa_ossl_finish, RSA_FLAG_FIPS_METHOD, /* flags */ NULL, 0, /* rsa_sign */ 0, /* rsa_verify */ NULL /* rsa_keygen */ }; const RSA_METHOD *RSA_PKCS1_OpenSSL(void) { return &rsa_pkcs1_ossl_meth; } static int rsa_ossl_public_encrypt(int flen, const unsigned char *from, unsigned char *to, RSA *rsa, int padding) { BIGNUM *f, *ret; int i, j, k, num = 0, r = -1; unsigned char *buf = NULL; BN_CTX *ctx = NULL; if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) { RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT, RSA_R_MODULUS_TOO_LARGE); return -1; } if (BN_ucmp(rsa->n, rsa->e) <= 0) { RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE); return -1; } /* for large moduli, enforce exponent limit */ if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) { if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) { RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE); return -1; } } if ((ctx = BN_CTX_new()) == NULL) goto err; BN_CTX_start(ctx); f = BN_CTX_get(ctx); ret = BN_CTX_get(ctx); num = BN_num_bytes(rsa->n); buf = OPENSSL_malloc(num); if (f == NULL || ret == NULL || buf == NULL) { RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT, ERR_R_MALLOC_FAILURE); goto err; } switch (padding) { case RSA_PKCS1_PADDING: i = RSA_padding_add_PKCS1_type_2(buf, num, from, flen); break; case RSA_PKCS1_OAEP_PADDING: i = RSA_padding_add_PKCS1_OAEP(buf, num, from, flen, NULL, 0); break; case RSA_SSLV23_PADDING: i = RSA_padding_add_SSLv23(buf, num, from, flen); break; case RSA_NO_PADDING: i = RSA_padding_add_none(buf, num, from, flen); break; default: RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT, RSA_R_UNKNOWN_PADDING_TYPE); goto err; } if (i <= 0) goto err; if (BN_bin2bn(buf, num, f) == NULL) goto err; if (BN_ucmp(f, rsa->n) >= 0) { /* usually the padding functions would catch this */ RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT, RSA_R_DATA_TOO_LARGE_FOR_MODULUS); goto err; } if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) if (!BN_MONT_CTX_set_locked (&rsa->_method_mod_n, rsa->lock, rsa->n, ctx)) goto err; if (!rsa->meth->bn_mod_exp(ret, f, rsa->e, rsa->n, ctx, rsa->_method_mod_n)) goto err; /* * put in leading 0 bytes if the number is less than the length of the * modulus */ j = BN_num_bytes(ret); i = BN_bn2bin(ret, &(to[num - j])); for (k = 0; k < (num - i); k++) to[k] = 0; r = num; err: if (ctx != NULL) BN_CTX_end(ctx); BN_CTX_free(ctx); OPENSSL_clear_free(buf, num); return (r); } static BN_BLINDING *rsa_get_blinding(RSA *rsa, int *local, BN_CTX *ctx) { BN_BLINDING *ret; CRYPTO_THREAD_write_lock(rsa->lock); if (rsa->blinding == NULL) { rsa->blinding = RSA_setup_blinding(rsa, ctx); } ret = rsa->blinding; if (ret == NULL) goto err; if (BN_BLINDING_is_current_thread(ret)) { /* rsa->blinding is ours! */ *local = 1; } else { /* resort to rsa->mt_blinding instead */ /* * instructs rsa_blinding_convert(), rsa_blinding_invert() that the * BN_BLINDING is shared, meaning that accesses require locks, and * that the blinding factor must be stored outside the BN_BLINDING */ *local = 0; if (rsa->mt_blinding == NULL) { rsa->mt_blinding = RSA_setup_blinding(rsa, ctx); } ret = rsa->mt_blinding; } err: CRYPTO_THREAD_unlock(rsa->lock); return ret; } static int rsa_blinding_convert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind, BN_CTX *ctx) { if (unblind == NULL) /* * Local blinding: store the unblinding factor in BN_BLINDING. */ return BN_BLINDING_convert_ex(f, NULL, b, ctx); else { /* * Shared blinding: store the unblinding factor outside BN_BLINDING. */ int ret; BN_BLINDING_lock(b); ret = BN_BLINDING_convert_ex(f, unblind, b, ctx); BN_BLINDING_unlock(b); return ret; } } static int rsa_blinding_invert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind, BN_CTX *ctx) { /* * For local blinding, unblind is set to NULL, and BN_BLINDING_invert_ex * will use the unblinding factor stored in BN_BLINDING. If BN_BLINDING * is shared between threads, unblind must be non-null: * BN_BLINDING_invert_ex will then use the local unblinding factor, and * will only read the modulus from BN_BLINDING. In both cases it's safe * to access the blinding without a lock. */ return BN_BLINDING_invert_ex(f, unblind, b, ctx); } /* signing */ static int rsa_ossl_private_encrypt(int flen, const unsigned char *from, unsigned char *to, RSA *rsa, int padding) { BIGNUM *f, *ret, *res; int i, j, k, num = 0, r = -1; unsigned char *buf = NULL; BN_CTX *ctx = NULL; int local_blinding = 0; /* * Used only if the blinding structure is shared. A non-NULL unblind * instructs rsa_blinding_convert() and rsa_blinding_invert() to store * the unblinding factor outside the blinding structure. */ BIGNUM *unblind = NULL; BN_BLINDING *blinding = NULL; if ((ctx = BN_CTX_new()) == NULL) goto err; BN_CTX_start(ctx); f = BN_CTX_get(ctx); ret = BN_CTX_get(ctx); num = BN_num_bytes(rsa->n); buf = OPENSSL_malloc(num); if (f == NULL || ret == NULL || buf == NULL) { RSAerr(RSA_F_RSA_OSSL_PRIVATE_ENCRYPT, ERR_R_MALLOC_FAILURE); goto err; } switch (padding) { case RSA_PKCS1_PADDING: i = RSA_padding_add_PKCS1_type_1(buf, num, from, flen); break; case RSA_X931_PADDING: i = RSA_padding_add_X931(buf, num, from, flen); break; case RSA_NO_PADDING: i = RSA_padding_add_none(buf, num, from, flen); break; case RSA_SSLV23_PADDING: default: RSAerr(RSA_F_RSA_OSSL_PRIVATE_ENCRYPT, RSA_R_UNKNOWN_PADDING_TYPE); goto err; } if (i <= 0) goto err; if (BN_bin2bn(buf, num, f) == NULL) goto err; if (BN_ucmp(f, rsa->n) >= 0) { /* usually the padding functions would catch this */ RSAerr(RSA_F_RSA_OSSL_PRIVATE_ENCRYPT, RSA_R_DATA_TOO_LARGE_FOR_MODULUS); goto err; } if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) { blinding = rsa_get_blinding(rsa, &local_blinding, ctx); if (blinding == NULL) { RSAerr(RSA_F_RSA_OSSL_PRIVATE_ENCRYPT, ERR_R_INTERNAL_ERROR); goto err; } } if (blinding != NULL) { if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL)) { RSAerr(RSA_F_RSA_OSSL_PRIVATE_ENCRYPT, ERR_R_MALLOC_FAILURE); goto err; } if (!rsa_blinding_convert(blinding, f, unblind, ctx)) goto err; } if ((rsa->flags & RSA_FLAG_EXT_PKEY) || ((rsa->p != NULL) && (rsa->q != NULL) && (rsa->dmp1 != NULL) && (rsa->dmq1 != NULL) && (rsa->iqmp != NULL))) { if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err; } else { BIGNUM *d = NULL, *local_d = NULL; if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) { local_d = d = BN_new(); if (d == NULL) { RSAerr(RSA_F_RSA_OSSL_PRIVATE_ENCRYPT, ERR_R_MALLOC_FAILURE); goto err; } BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME); } else { d = rsa->d; } if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) if (!BN_MONT_CTX_set_locked (&rsa->_method_mod_n, rsa->lock, rsa->n, ctx)) { BN_free(local_d); goto err; } if (!rsa->meth->bn_mod_exp(ret, f, d, rsa->n, ctx, rsa->_method_mod_n)) { BN_free(local_d); goto err; } /* We MUST free local_d before any further use of rsa->d */ BN_free(local_d); } if (blinding) if (!rsa_blinding_invert(blinding, ret, unblind, ctx)) goto err; if (padding == RSA_X931_PADDING) { BN_sub(f, rsa->n, ret); if (BN_cmp(ret, f) > 0) res = f; else res = ret; } else res = ret; /* * put in leading 0 bytes if the number is less than the length of the * modulus */ j = BN_num_bytes(res); i = BN_bn2bin(res, &(to[num - j])); for (k = 0; k < (num - i); k++) to[k] = 0; r = num; err: if (ctx != NULL) BN_CTX_end(ctx); BN_CTX_free(ctx); OPENSSL_clear_free(buf, num); return (r); } static int rsa_ossl_private_decrypt(int flen, const unsigned char *from, unsigned char *to, RSA *rsa, int padding) { BIGNUM *f, *ret; int j, num = 0, r = -1; unsigned char *p; unsigned char *buf = NULL; BN_CTX *ctx = NULL; int local_blinding = 0; /* * Used only if the blinding structure is shared. A non-NULL unblind * instructs rsa_blinding_convert() and rsa_blinding_invert() to store * the unblinding factor outside the blinding structure. */ BIGNUM *unblind = NULL; BN_BLINDING *blinding = NULL; if ((ctx = BN_CTX_new()) == NULL) goto err; BN_CTX_start(ctx); f = BN_CTX_get(ctx); ret = BN_CTX_get(ctx); num = BN_num_bytes(rsa->n); buf = OPENSSL_malloc(num); if (f == NULL || ret == NULL || buf == NULL) { RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT, ERR_R_MALLOC_FAILURE); goto err; } /* * This check was for equality but PGP does evil things and chops off the * top '0' bytes */ if (flen > num) { RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT, RSA_R_DATA_GREATER_THAN_MOD_LEN); goto err; } /* make data into a big number */ if (BN_bin2bn(from, (int)flen, f) == NULL) goto err; if (BN_ucmp(f, rsa->n) >= 0) { RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT, RSA_R_DATA_TOO_LARGE_FOR_MODULUS); goto err; } if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) { blinding = rsa_get_blinding(rsa, &local_blinding, ctx); if (blinding == NULL) { RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT, ERR_R_INTERNAL_ERROR); goto err; } } if (blinding != NULL) { if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL)) { RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT, ERR_R_MALLOC_FAILURE); goto err; } if (!rsa_blinding_convert(blinding, f, unblind, ctx)) goto err; } /* do the decrypt */ if ((rsa->flags & RSA_FLAG_EXT_PKEY) || ((rsa->p != NULL) && (rsa->q != NULL) && (rsa->dmp1 != NULL) && (rsa->dmq1 != NULL) && (rsa->iqmp != NULL))) { if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err; } else { BIGNUM *d = NULL, *local_d = NULL; if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) { local_d = d = BN_new(); if (d == NULL) { RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT, ERR_R_MALLOC_FAILURE); goto err; } BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME); } else { d = rsa->d; } if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) if (!BN_MONT_CTX_set_locked (&rsa->_method_mod_n, rsa->lock, rsa->n, ctx)) { BN_free(local_d); goto err; } if (!rsa->meth->bn_mod_exp(ret, f, d, rsa->n, ctx, rsa->_method_mod_n)) { BN_free(local_d); goto err; } /* We MUST free local_d before any further use of rsa->d */ BN_free(local_d); } if (blinding) if (!rsa_blinding_invert(blinding, ret, unblind, ctx)) goto err; p = buf; j = BN_bn2bin(ret, p); /* j is only used with no-padding mode */ switch (padding) { case RSA_PKCS1_PADDING: r = RSA_padding_check_PKCS1_type_2(to, num, buf, j, num); break; case RSA_PKCS1_OAEP_PADDING: r = RSA_padding_check_PKCS1_OAEP(to, num, buf, j, num, NULL, 0); break; case RSA_SSLV23_PADDING: r = RSA_padding_check_SSLv23(to, num, buf, j, num); break; case RSA_NO_PADDING: r = RSA_padding_check_none(to, num, buf, j, num); break; default: RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT, RSA_R_UNKNOWN_PADDING_TYPE); goto err; } if (r < 0) RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT, RSA_R_PADDING_CHECK_FAILED); err: if (ctx != NULL) BN_CTX_end(ctx); BN_CTX_free(ctx); OPENSSL_clear_free(buf, num); return (r); } /* signature verification */ static int rsa_ossl_public_decrypt(int flen, const unsigned char *from, unsigned char *to, RSA *rsa, int padding) { BIGNUM *f, *ret; int i, num = 0, r = -1; unsigned char *p; unsigned char *buf = NULL; BN_CTX *ctx = NULL; if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) { RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT, RSA_R_MODULUS_TOO_LARGE); return -1; } if (BN_ucmp(rsa->n, rsa->e) <= 0) { RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE); return -1; } /* for large moduli, enforce exponent limit */ if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) { if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) { RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE); return -1; } } if ((ctx = BN_CTX_new()) == NULL) goto err; BN_CTX_start(ctx); f = BN_CTX_get(ctx); ret = BN_CTX_get(ctx); num = BN_num_bytes(rsa->n); buf = OPENSSL_malloc(num); if (f == NULL || ret == NULL || buf == NULL) { RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT, ERR_R_MALLOC_FAILURE); goto err; } /* * This check was for equality but PGP does evil things and chops off the * top '0' bytes */ if (flen > num) { RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT, RSA_R_DATA_GREATER_THAN_MOD_LEN); goto err; } if (BN_bin2bn(from, flen, f) == NULL) goto err; if (BN_ucmp(f, rsa->n) >= 0) { RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT, RSA_R_DATA_TOO_LARGE_FOR_MODULUS); goto err; } if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) if (!BN_MONT_CTX_set_locked (&rsa->_method_mod_n, rsa->lock, rsa->n, ctx)) goto err; if (!rsa->meth->bn_mod_exp(ret, f, rsa->e, rsa->n, ctx, rsa->_method_mod_n)) goto err; if ((padding == RSA_X931_PADDING) && ((bn_get_words(ret)[0] & 0xf) != 12)) if (!BN_sub(ret, rsa->n, ret)) goto err; p = buf; i = BN_bn2bin(ret, p); switch (padding) { case RSA_PKCS1_PADDING: r = RSA_padding_check_PKCS1_type_1(to, num, buf, i, num); break; case RSA_X931_PADDING: r = RSA_padding_check_X931(to, num, buf, i, num); break; case RSA_NO_PADDING: r = RSA_padding_check_none(to, num, buf, i, num); break; default: RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT, RSA_R_UNKNOWN_PADDING_TYPE); goto err; } if (r < 0) RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT, RSA_R_PADDING_CHECK_FAILED); err: if (ctx != NULL) BN_CTX_end(ctx); BN_CTX_free(ctx); OPENSSL_clear_free(buf, num); return (r); } static int rsa_ossl_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx) { BIGNUM *r1, *m1, *vrfy; int ret = 0; BN_CTX_start(ctx); r1 = BN_CTX_get(ctx); m1 = BN_CTX_get(ctx); vrfy = BN_CTX_get(ctx); { BIGNUM *local_p = NULL, *local_q = NULL; BIGNUM *p = NULL, *q = NULL; /* * Make sure BN_mod_inverse in Montgomery initialization uses the * BN_FLG_CONSTTIME flag (unless RSA_FLAG_NO_CONSTTIME is set) */ if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) { local_p = p = BN_new(); if (p == NULL) goto err; BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME); local_q = q = BN_new(); if (q == NULL) { BN_free(local_p); goto err; } BN_with_flags(q, rsa->q, BN_FLG_CONSTTIME); } else { p = rsa->p; q = rsa->q; } if (rsa->flags & RSA_FLAG_CACHE_PRIVATE) { if (!BN_MONT_CTX_set_locked (&rsa->_method_mod_p, rsa->lock, p, ctx) || !BN_MONT_CTX_set_locked(&rsa->_method_mod_q, rsa->lock, q, ctx)) { BN_free(local_p); BN_free(local_q); goto err; } } /* * We MUST free local_p and local_q before any further use of rsa->p and * rsa->q */ BN_free(local_p); BN_free(local_q); } if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) if (!BN_MONT_CTX_set_locked (&rsa->_method_mod_n, rsa->lock, rsa->n, ctx)) goto err; /* compute I mod q */ { BIGNUM *local_c = NULL; const BIGNUM *c; if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) { local_c = BN_new(); if (local_c == NULL) goto err; BN_with_flags(local_c, I, BN_FLG_CONSTTIME); c = local_c; } else { c = I; } if (!BN_mod(r1, c, rsa->q, ctx)) { BN_free(local_c); goto err; } { BIGNUM *local_dmq1 = NULL, *dmq1; /* compute r1^dmq1 mod q */ if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) { dmq1 = local_dmq1 = BN_new(); if (local_dmq1 == NULL) { BN_free(local_c); goto err; } BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME); } else { dmq1 = rsa->dmq1; } if (!rsa->meth->bn_mod_exp(m1, r1, dmq1, rsa->q, ctx, rsa->_method_mod_q)) { BN_free(local_c); BN_free(local_dmq1); goto err; } /* We MUST free local_dmq1 before any further use of rsa->dmq1 */ BN_free(local_dmq1); } /* compute I mod p */ if (!BN_mod(r1, c, rsa->p, ctx)) { BN_free(local_c); goto err; } /* We MUST free local_c before any further use of I */ BN_free(local_c); } { BIGNUM *local_dmp1 = NULL, *dmp1; /* compute r1^dmp1 mod p */ if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) { dmp1 = local_dmp1 = BN_new(); if (local_dmp1 == NULL) goto err; BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME); } else { dmp1 = rsa->dmp1; } if (!rsa->meth->bn_mod_exp(r0, r1, dmp1, rsa->p, ctx, rsa->_method_mod_p)) { BN_free(local_dmp1); goto err; } /* We MUST free local_dmp1 before any further use of rsa->dmp1 */ BN_free(local_dmp1); } if (!BN_sub(r0, r0, m1)) goto err; /* * This will help stop the size of r0 increasing, which does affect the * multiply if it optimised for a power of 2 size */ if (BN_is_negative(r0)) if (!BN_add(r0, r0, rsa->p)) goto err; if (!BN_mul(r1, r0, rsa->iqmp, ctx)) goto err; { BIGNUM *local_r1 = NULL, *pr1; /* Turn BN_FLG_CONSTTIME flag on before division operation */ if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) { pr1 = local_r1 = BN_new(); if (local_r1 == NULL) goto err; BN_with_flags(pr1, r1, BN_FLG_CONSTTIME); } else { pr1 = r1; } if (!BN_mod(r0, pr1, rsa->p, ctx)) { BN_free(local_r1); goto err; } /* We MUST free local_r1 before any further use of r1 */ BN_free(local_r1); } /* * If p < q it is occasionally possible for the correction of adding 'p' * if r0 is negative above to leave the result still negative. This can * break the private key operations: the following second correction * should *always* correct this rare occurrence. This will *never* happen * with OpenSSL generated keys because they ensure p > q [steve] */ if (BN_is_negative(r0)) if (!BN_add(r0, r0, rsa->p)) goto err; if (!BN_mul(r1, r0, rsa->q, ctx)) goto err; if (!BN_add(r0, r1, m1)) goto err; if (rsa->e && rsa->n) { if (!rsa->meth->bn_mod_exp(vrfy, r0, rsa->e, rsa->n, ctx, rsa->_method_mod_n)) goto err; /* * If 'I' was greater than (or equal to) rsa->n, the operation will * be equivalent to using 'I mod n'. However, the result of the * verify will *always* be less than 'n' so we don't check for * absolute equality, just congruency. */ if (!BN_sub(vrfy, vrfy, I)) goto err; if (!BN_mod(vrfy, vrfy, rsa->n, ctx)) goto err; if (BN_is_negative(vrfy)) if (!BN_add(vrfy, vrfy, rsa->n)) goto err; if (!BN_is_zero(vrfy)) { /* * 'I' and 'vrfy' aren't congruent mod n. Don't leak * miscalculated CRT output, just do a raw (slower) mod_exp and * return that instead. */ BIGNUM *local_d = NULL; BIGNUM *d = NULL; if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) { local_d = d = BN_new(); if (d == NULL) goto err; BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME); } else { d = rsa->d; } if (!rsa->meth->bn_mod_exp(r0, I, d, rsa->n, ctx, rsa->_method_mod_n)) { BN_free(local_d); goto err; } /* We MUST free local_d before any further use of rsa->d */ BN_free(local_d); } } ret = 1; err: BN_CTX_end(ctx); return (ret); } static int rsa_ossl_init(RSA *rsa) { rsa->flags |= RSA_FLAG_CACHE_PUBLIC | RSA_FLAG_CACHE_PRIVATE; return (1); } static int rsa_ossl_finish(RSA *rsa) { BN_MONT_CTX_free(rsa->_method_mod_n); BN_MONT_CTX_free(rsa->_method_mod_p); BN_MONT_CTX_free(rsa->_method_mod_q); return (1); } #endif