diff options
Diffstat (limited to 'openssl-1.1.0h/crypto/rsa/rsa_ossl.c')
| -rw-r--r-- | openssl-1.1.0h/crypto/rsa/rsa_ossl.c | 800 |
1 files changed, 800 insertions, 0 deletions
diff --git a/openssl-1.1.0h/crypto/rsa/rsa_ossl.c b/openssl-1.1.0h/crypto/rsa/rsa_ossl.c new file mode 100644 index 0000000..62a8895 --- /dev/null +++ b/openssl-1.1.0h/crypto/rsa/rsa_ossl.c @@ -0,0 +1,800 @@ +/* + * Copyright 1995-2016 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 "internal/cryptlib.h" +#include "internal/bn_int.h" +#include "rsa_locl.h" + +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", + 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 */ +}; + +static const RSA_METHOD *default_RSA_meth = &rsa_pkcs1_ossl_meth; + +void RSA_set_default_method(const RSA_METHOD *meth) +{ + default_RSA_meth = meth; +} + +const RSA_METHOD *RSA_get_default_method(void) +{ + return default_RSA_meth; +} + +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 = 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); + + if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) + if (!BN_MONT_CTX_set_locked + (&rsa->_method_mod_n, rsa->lock, rsa->n, ctx)) { + BN_free(d); + goto err; + } + + if (!rsa->meth->bn_mod_exp(ret, f, d, rsa->n, ctx, + rsa->_method_mod_n)) { + BN_free(d); + goto err; + } + /* We MUST free d before any further use of rsa->d */ + BN_free(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 = 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); + + if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) + if (!BN_MONT_CTX_set_locked + (&rsa->_method_mod_n, rsa->lock, rsa->n, ctx)) { + BN_free(d); + goto err; + } + if (!rsa->meth->bn_mod_exp(ret, f, d, rsa->n, ctx, + rsa->_method_mod_n)) { + BN_free(d); + goto err; + } + /* We MUST free d before any further use of rsa->d */ + BN_free(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); + if (vrfy == NULL) + goto err; + + { + BIGNUM *p = BN_new(), *q = BN_new(); + + /* + * Make sure BN_mod_inverse in Montgomery initialization uses the + * BN_FLG_CONSTTIME flag + */ + if (p == NULL || q == NULL) { + BN_free(p); + BN_free(q); + goto err; + } + BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME); + BN_with_flags(q, rsa->q, BN_FLG_CONSTTIME); + + 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(p); + BN_free(q); + goto err; + } + } + /* + * We MUST free p and q before any further use of rsa->p and rsa->q + */ + BN_free(p); + BN_free(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 *c = BN_new(); + if (c == NULL) + goto err; + BN_with_flags(c, I, BN_FLG_CONSTTIME); + + if (!BN_mod(r1, c, rsa->q, ctx)) { + BN_free(c); + goto err; + } + + { + BIGNUM *dmq1 = BN_new(); + if (dmq1 == NULL) { + BN_free(c); + goto err; + } + BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME); + + /* compute r1^dmq1 mod q */ + if (!rsa->meth->bn_mod_exp(m1, r1, dmq1, rsa->q, ctx, + rsa->_method_mod_q)) { + BN_free(c); + BN_free(dmq1); + goto err; + } + /* We MUST free dmq1 before any further use of rsa->dmq1 */ + BN_free(dmq1); + } + + /* compute I mod p */ + if (!BN_mod(r1, c, rsa->p, ctx)) { + BN_free(c); + goto err; + } + /* We MUST free c before any further use of I */ + BN_free(c); + } + + { + BIGNUM *dmp1 = BN_new(); + if (dmp1 == NULL) + goto err; + BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME); + + /* compute r1^dmp1 mod p */ + if (!rsa->meth->bn_mod_exp(r0, r1, dmp1, rsa->p, ctx, + rsa->_method_mod_p)) { + BN_free(dmp1); + goto err; + } + /* We MUST free dmp1 before any further use of rsa->dmp1 */ + BN_free(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 *pr1 = BN_new(); + if (pr1 == NULL) + goto err; + BN_with_flags(pr1, r1, BN_FLG_CONSTTIME); + + if (!BN_mod(r0, pr1, rsa->p, ctx)) { + BN_free(pr1); + goto err; + } + /* We MUST free pr1 before any further use of r1 */ + BN_free(pr1); + } + + /* + * 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 *d = BN_new(); + if (d == NULL) + goto err; + BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME); + + if (!rsa->meth->bn_mod_exp(r0, I, d, rsa->n, ctx, + rsa->_method_mod_n)) { + BN_free(d); + goto err; + } + /* We MUST free d before any further use of rsa->d */ + BN_free(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); +} |