Commit 91637810 authored by Nick Mathewson's avatar Nick Mathewson 🥄
Browse files

Merge branch 'trove_2020_002_035' into trove_2020_002_041

parents dd6e2277 f958b537
......@@ -736,7 +736,7 @@ crypto_pk_asn1_decode_private(const char *str, size_t len, int max_bits)
if (output) {
const int bits = SECKEY_PublicKeyStrengthInBits(output->pubkey);
if (max_bits > 0 && bits > max_bits) {
if (max_bits >= 0 && bits > max_bits) {
log_info(LD_CRYPTO, "Private key longer than expected.");
crypto_pk_free(output);
output = NULL;
......
......@@ -33,6 +33,7 @@ ENABLE_GCC_WARNING(redundant-decls)
#include "lib/encoding/binascii.h"
#include <string.h>
#include <stdbool.h>
/** Declaration for crypto_pk_t structure. */
struct crypto_pk_t
......@@ -564,6 +565,56 @@ crypto_pk_asn1_encode_private(const crypto_pk_t *pk, char *dest,
return len;
}
/** Check whether any component of a private key is too large in a way that
* seems likely to make verification too expensive. Return true if it's too
* long, and false otherwise. */
static bool
rsa_private_key_too_long(RSA *rsa, int max_bits)
{
const BIGNUM *n, *e, *p, *q, *d, *dmp1, *dmq1, *iqmp;
#ifdef OPENSSL_1_1_API
n = RSA_get0_n(rsa);
e = RSA_get0_e(rsa);
p = RSA_get0_p(rsa);
q = RSA_get0_q(rsa);
d = RSA_get0_d(rsa);
dmp1 = RSA_get0_dmp1(rsa);
dmq1 = RSA_get0_dmq1(rsa);
iqmp = RSA_get0_iqmp(rsa);
if (RSA_bits(rsa) > max_bits)
return true;
#else
n = rsa->n;
e = rsa->e;
p = rsa->p;
q = rsa->q;
d = rsa->d;
dmp1 = rsa->dmp1;
dmq1 = rsa->dmq1;
iqmp = rsa->iqmp;
#endif
if (n && BN_num_bits(n) > max_bits)
return true;
if (e && BN_num_bits(e) > max_bits)
return true;
if (p && BN_num_bits(p) > max_bits)
return true;
if (q && BN_num_bits(q) > max_bits)
return true;
if (d && BN_num_bits(d) > max_bits)
return true;
if (dmp1 && BN_num_bits(dmp1) > max_bits)
return true;
if (dmq1 && BN_num_bits(dmq1) > max_bits)
return true;
if (iqmp && BN_num_bits(iqmp) > max_bits)
return true;
return false;
}
/** Decode an ASN.1-encoded private key from <b>str</b>; return the result on
* success and NULL on failure.
*
......@@ -584,11 +635,7 @@ crypto_pk_asn1_decode_private(const char *str, size_t len, int max_bits)
crypto_openssl_log_errors(LOG_WARN,"decoding private key");
return NULL;
}
#ifdef OPENSSL_1_1_API
if (max_bits >= 0 && RSA_bits(rsa) > max_bits) {
#else
if (max_bits >= 0 && rsa->n && BN_num_bits(rsa->n) > max_bits) {
#endif
if (max_bits >= 0 && rsa_private_key_too_long(rsa, max_bits)) {
log_info(LD_CRYPTO, "Private key longer than expected.");
RSA_free(rsa);
return NULL;
......
......@@ -1349,6 +1349,21 @@ test_crypto_pk_bad_size(void *arg)
pk2 = crypto_pk_asn1_decode_private(buf, n, 1020);
tt_assert(! pk2);
/* Set the max bit count one bit smaller: we should refuse to decode the
key.*/
pk2 = crypto_pk_asn1_decode_private(buf, n, 1023);
tt_assert(! pk2);
/* Correct size: should work. */
pk2 = crypto_pk_asn1_decode_private(buf, n, 1024);
tt_assert(pk2);
crypto_pk_free(pk2);
/* One bit larger: should work. */
pk2 = crypto_pk_asn1_decode_private(buf, n, 1025);
tt_assert(pk2);
crypto_pk_free(pk2);
/* Set the max bit count larger: it should decode fine. */
pk2 = crypto_pk_asn1_decode_private(buf, n, 2048);
tt_assert(pk2);
......
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