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Import OpenSSL 1.1.0l

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This commit is contained in:
Steve Dower
2019-09-16 11:19:00 +01:00
parent 697f7e1f24
commit 42e1dddc24
80 changed files with 1888 additions and 995 deletions
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92
crypto/rsa/rsa_oaep.c
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@@ -1,5 +1,5 @@
/*
* Copyright 1999-2018 The OpenSSL Project Authors. All Rights Reserved.
* Copyright 1999-2019 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
@@ -126,7 +126,7 @@ int RSA_padding_check_PKCS1_OAEP_mgf1(unsigned char *to, int tlen,
const EVP_MD *mgf1md)
{
int i, dblen = 0, mlen = -1, one_index = 0, msg_index;
unsigned int good, found_one_byte;
unsigned int good = 0, found_one_byte, mask;
const unsigned char *maskedseed, *maskeddb;
/*
* |em| is the encoded message, zero-padded to exactly |num| bytes: em =
@@ -149,12 +149,15 @@ int RSA_padding_check_PKCS1_OAEP_mgf1(unsigned char *to, int tlen,
* |num| is the length of the modulus; |flen| is the length of the
* encoded message. Therefore, for any |from| that was obtained by
* decrypting a ciphertext, we must have |flen| <= |num|. Similarly,
* num < 2 * mdlen + 2 must hold for the modulus irrespective of
* |num| >= 2 * |mdlen| + 2 must hold for the modulus irrespective of
* the ciphertext, see PKCS #1 v2.2, section 7.1.2.
* This does not leak any side-channel information.
*/
if (num < flen || num < 2 * mdlen + 2)
goto decoding_err;
if (num < flen || num < 2 * mdlen + 2) {
RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP_MGF1,
RSA_R_OAEP_DECODING_ERROR);
return -1;
}
dblen = num - mdlen - 1;
db = OPENSSL_malloc(dblen);
@@ -163,24 +166,24 @@ int RSA_padding_check_PKCS1_OAEP_mgf1(unsigned char *to, int tlen,
goto cleanup;
}
if (flen != num) {
em = OPENSSL_zalloc(num);
if (em == NULL) {
RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP_MGF1,
ERR_R_MALLOC_FAILURE);
goto cleanup;
}
em = OPENSSL_malloc(num);
if (em == NULL) {
RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP_MGF1,
ERR_R_MALLOC_FAILURE);
goto cleanup;
}
/*
* Caller is encouraged to pass zero-padded message created with
* BN_bn2binpad, but if it doesn't, we do this zero-padding copy
* to avoid leaking that information. The copy still leaks some
* side-channel information, but it's impossible to have a fixed
* memory access pattern since we can't read out of the bounds of
* |from|.
*/
memcpy(em + num - flen, from, flen);
from = em;
/*
* Caller is encouraged to pass zero-padded message created with
* BN_bn2binpad. Trouble is that since we can't read out of |from|'s
* bounds, it's impossible to have an invariant memory access pattern
* in case |from| was not zero-padded in advance.
*/
for (from += flen, em += num, i = 0; i < num; i++) {
mask = ~constant_time_is_zero(flen);
flen -= 1 & mask;
from -= 1 & mask;
*--em = *from & mask;
}
/*
@@ -188,10 +191,10 @@ int RSA_padding_check_PKCS1_OAEP_mgf1(unsigned char *to, int tlen,
* true. See James H. Manger, "A Chosen Ciphertext Attack on RSA
* Optimal Asymmetric Encryption Padding (OAEP) [...]", CRYPTO 2001).
*/
good = constant_time_is_zero(from[0]);
good = constant_time_is_zero(em[0]);
maskedseed = from + 1;
maskeddb = from + 1 + mdlen;
maskedseed = em + 1;
maskeddb = em + 1 + mdlen;
if (PKCS1_MGF1(seed, mdlen, maskeddb, dblen, mgf1md))
goto cleanup;
@@ -228,32 +231,49 @@ int RSA_padding_check_PKCS1_OAEP_mgf1(unsigned char *to, int tlen,
* so plaintext-awareness ensures timing side-channels are no longer a
* concern.
*/
if (!good)
goto decoding_err;
msg_index = one_index + 1;
mlen = dblen - msg_index;
if (tlen < mlen) {
RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP_MGF1, RSA_R_DATA_TOO_LARGE);
mlen = -1;
} else {
memcpy(to, db + msg_index, mlen);
goto cleanup;
/*
* For good measure, do this check in constant time as well.
*/
good &= constant_time_ge(tlen, mlen);
/*
* Move the result in-place by |dblen|-|mdlen|-1-|mlen| bytes to the left.
* Then if |good| move |mlen| bytes from |db|+|mdlen|+1 to |to|.
* Otherwise leave |to| unchanged.
* Copy the memory back in a way that does not reveal the size of
* the data being copied via a timing side channel. This requires copying
* parts of the buffer multiple times based on the bits set in the real
* length. Clear bits do a non-copy with identical access pattern.
* The loop below has overall complexity of O(N*log(N)).
*/
tlen = constant_time_select_int(constant_time_lt(dblen - mdlen - 1, tlen),
dblen - mdlen - 1, tlen);
for (msg_index = 1; msg_index < dblen - mdlen - 1; msg_index <<= 1) {
mask = ~constant_time_eq(msg_index & (dblen - mdlen - 1 - mlen), 0);
for (i = mdlen + 1; i < dblen - msg_index; i++)
db[i] = constant_time_select_8(mask, db[i + msg_index], db[i]);
}
for (i = 0; i < tlen; i++) {
mask = good & constant_time_lt(i, mlen);
to[i] = constant_time_select_8(mask, db[i + mdlen + 1], to[i]);
}
decoding_err:
/*
* To avoid chosen ciphertext attacks, the error message should not
* reveal which kind of decoding error happened.
*/
RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP_MGF1,
RSA_R_OAEP_DECODING_ERROR);
err_clear_last_constant_time(1 & good);
cleanup:
OPENSSL_cleanse(seed, sizeof(seed));
OPENSSL_clear_free(db, dblen);
OPENSSL_clear_free(em, num);
return mlen;
return constant_time_select_int(good, mlen, -1);
}
int PKCS1_MGF1(unsigned char *mask, long len,