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Import OpenSSL 1.0.2s

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This commit is contained in:
Steve Dower
2019-06-17 08:41:08 -07:00
parent 4155d3c2bd
commit e6c823a7e5
125 changed files with 136502 additions and 136422 deletions
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139
crypto/rsa/rsa_ssl.c
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@@ -61,6 +61,7 @@
#include <openssl/bn.h>
#include <openssl/rsa.h>
#include <openssl/rand.h>
#include "constant_time_locl.h"
int RSA_padding_add_SSLv23(unsigned char *to, int tlen,
const unsigned char *from, int flen)
@@ -101,57 +102,119 @@ int RSA_padding_add_SSLv23(unsigned char *to, int tlen,
return (1);
}
/*
* Copy of RSA_padding_check_PKCS1_type_2 with a twist that rejects padding
* if nul delimiter is not preceded by 8 consecutive 0x03 bytes. It also
* preserves error code reporting for backward compatibility.
*/
int RSA_padding_check_SSLv23(unsigned char *to, int tlen,
const unsigned char *from, int flen, int num)
{
int i, j, k;
const unsigned char *p;
int i;
/* |em| is the encoded message, zero-padded to exactly |num| bytes */
unsigned char *em = NULL;
unsigned int good, found_zero_byte, mask, threes_in_row;
int zero_index = 0, msg_index, mlen = -1, err;
p = from;
if (flen < 10) {
if (tlen <= 0 || flen <= 0)
return -1;
if (flen > num || num < 11) {
RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23, RSA_R_DATA_TOO_SMALL);
return (-1);
}
/* Accept even zero-padded input */
if (flen == num) {
if (*(p++) != 0) {
RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23, RSA_R_BLOCK_TYPE_IS_NOT_02);
return -1;
}
flen--;
em = OPENSSL_malloc(num);
if (em == NULL) {
RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23, ERR_R_MALLOC_FAILURE);
return -1;
}
if ((num != (flen + 1)) || (*(p++) != 02)) {
RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23, RSA_R_BLOCK_TYPE_IS_NOT_02);
return (-1);
/*
* 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;
}
good = constant_time_is_zero(em[0]);
good &= constant_time_eq(em[1], 2);
err = constant_time_select_int(good, 0, RSA_R_BLOCK_TYPE_IS_NOT_02);
mask = ~good;
/* scan over padding data */
j = flen - 1; /* one for type */
for (i = 0; i < j; i++)
if (*(p++) == 0)
break;
found_zero_byte = 0;
threes_in_row = 0;
for (i = 2; i < num; i++) {
unsigned int equals0 = constant_time_is_zero(em[i]);
if ((i == j) || (i < 8)) {
RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23,
RSA_R_NULL_BEFORE_BLOCK_MISSING);
return (-1);
}
for (k = -9; k < -1; k++) {
if (p[k] != 0x03)
break;
}
if (k == -1) {
RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23, RSA_R_SSLV3_ROLLBACK_ATTACK);
return (-1);
zero_index = constant_time_select_int(~found_zero_byte & equals0,
i, zero_index);
found_zero_byte |= equals0;
threes_in_row += 1 & ~found_zero_byte;
threes_in_row &= found_zero_byte | constant_time_eq(em[i], 3);
}
i++; /* Skip over the '\0' */
j -= i;
if (j > tlen) {
RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23, RSA_R_DATA_TOO_LARGE);
return (-1);
}
memcpy(to, p, (unsigned int)j);
/*
* PS must be at least 8 bytes long, and it starts two bytes into |em|.
* If we never found a 0-byte, then |zero_index| is 0 and the check
* also fails.
*/
good &= constant_time_ge(zero_index, 2 + 8);
err = constant_time_select_int(mask | good, err,
RSA_R_NULL_BEFORE_BLOCK_MISSING);
mask = ~good;
return (j);
good &= constant_time_ge(threes_in_row, 8);
err = constant_time_select_int(mask | good, err,
RSA_R_SSLV3_ROLLBACK_ATTACK);
mask = ~good;
/*
* Skip the zero byte. This is incorrect if we never found a zero-byte
* but in this case we also do not copy the message out.
*/
msg_index = zero_index + 1;
mlen = num - msg_index;
/*
* For good measure, do this check in constant time as well.
*/
good &= constant_time_ge(tlen, mlen);
err = constant_time_select_int(mask | good, err, RSA_R_DATA_TOO_LARGE);
/*
* Move the result in-place by |num|-11-|mlen| bytes to the left.
* Then if |good| move |mlen| bytes from |em|+11 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(num - 11, tlen),
num - 11, tlen);
for (msg_index = 1; msg_index < num - 11; msg_index <<= 1) {
mask = ~constant_time_eq(msg_index & (num - 11 - mlen), 0);
for (i = 11; i < num - msg_index; i++)
em[i] = constant_time_select_8(mask, em[i + msg_index], em[i]);
}
for (i = 0; i < tlen; i++) {
mask = good & constant_time_lt(i, mlen);
to[i] = constant_time_select_8(mask, em[i + 11], to[i]);
}
OPENSSL_cleanse(em, num);
OPENSSL_free(em);
RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23, err);
err_clear_last_constant_time(1 & good);
return constant_time_select_int(good, mlen, -1);
}