Skip to content

Fix BIGNUM leak in _new_key_from_parameters on pre-3.x #195

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Draft
toddr-bot wants to merge 1 commit into
base: main
Choose a base branch
from
Draft

Fix BIGNUM leak in _new_key_from_parameters on pre-3.x #195

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
42 changes: 30 additions & 12 deletions RSA.xs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -913,6 +913,9 @@ _new_key_from_parameters(proto, n, e, d, p, q)
BIGNUM* dmq1 = NULL;
BIGNUM* iqmp = NULL;
int error = 0;
#if OPENSSL_VERSION_NUMBER < 0x30000000L
int xfer = 0;
#endif
#if OPENSSL_VERSION_NUMBER >= 0x30000000L
OSSL_PARAM *params = NULL;
EVP_PKEY_CTX *pctx = NULL;
Expand All @@ -936,6 +939,7 @@ _new_key_from_parameters(proto, n, e, d, p, q)
#if OLD_CRUFTY_SSL_VERSION
rsa->n = n;
rsa->e = e;
xfer = 1;
#endif
#if OPENSSL_VERSION_NUMBER >= 0x30000000L
THROW(OSSL_PARAM_BLD_push_BN(params_build, OSSL_PKEY_PARAM_RSA_N, n));
Expand All @@ -958,10 +962,12 @@ _new_key_from_parameters(proto, n, e, d, p, q)
#if OLD_CRUFTY_SSL_VERSION
rsa->p = p;
rsa->q = q;
xfer |= 2;
#else
#if OPENSSL_VERSION_NUMBER >= 0x30000000L
#else
THROW(RSA_set0_factors(rsa, p, q));
xfer |= 2;
#endif
#endif
THROW(p_minus_1 = BN_new());
Expand All @@ -976,13 +982,15 @@ _new_key_from_parameters(proto, n, e, d, p, q)
}
#if OLD_CRUFTY_SSL_VERSION
rsa->d = d;
xfer |= 4;
#else
#if OPENSSL_VERSION_NUMBER >= 0x30000000L
THROW(OSSL_PARAM_BLD_push_BN(params_build, OSSL_PKEY_PARAM_RSA_D, d));
THROW(OSSL_PARAM_BLD_push_BN(params_build, OSSL_PKEY_PARAM_RSA_FACTOR1, p));
THROW(OSSL_PARAM_BLD_push_BN(params_build, OSSL_PKEY_PARAM_RSA_FACTOR2, q));
#else
THROW(RSA_set0_key(rsa, n, e, d));
xfer |= (1|4);
#endif
#endif
THROW(dmp1 = BN_new());
Expand Down Expand Up @@ -1026,8 +1034,12 @@ _new_key_from_parameters(proto, n, e, d, p, q)
BN_clear_free(dmp1);
BN_clear_free(dmq1);
BN_clear_free(iqmp);
n = e = d = p = q = NULL;
#endif
/* NULL out all parameter variables — on 3.x they were just
freed above; on pre-3.x they were transferred to the RSA
struct via set0/direct-assign. Prevents the err handler
from double-freeing on a subsequent THROW (e.g. RSA_check_key). */
n = e = d = p = q = NULL;
dmp1 = dmq1 = iqmp = NULL;
BN_CTX_free(ctx);
ctx = NULL;
Expand All @@ -1049,7 +1061,7 @@ _new_key_from_parameters(proto, n, e, d, p, q)
else
{
#if OLD_CRUFTY_SSL_VERSION
rsa->d = d;
rsa->d = d; d = NULL; xfer |= 4;
#else
#if OPENSSL_VERSION_NUMBER >= 0x30000000L
if(d != NULL)
Expand All @@ -1070,7 +1082,8 @@ _new_key_from_parameters(proto, n, e, d, p, q)
BN_clear_free(d);
n = e = d = NULL;
#else
CHECK_OPEN_SSL(RSA_set0_key(rsa, n, e, d));
THROW(RSA_set0_key(rsa, n, e, d));
xfer |= (1|4); n = NULL; e = NULL; d = NULL;
#endif
#endif
}
Expand All @@ -1079,22 +1092,27 @@ _new_key_from_parameters(proto, n, e, d, p, q)
goto end;

err:
/* On pre-3.0, RSA_set0 / direct-assign transfers ownership;
xfer tracks which groups were transferred (bit 0=n+e,
bit 1=p+q, bit 2=d). On 3.0+, OSSL_PARAM_BLD copies
values so we always own the originals. */
#if OPENSSL_VERSION_NUMBER >= 0x30000000L
/* On 3.x, push_BN copies, so originals are always ours to free.
On pre-3.x, RSA_set0_key/set0_factors may have taken ownership,
so these are intentionally skipped (risk of double-free). */
BN_clear_free(n);
BN_clear_free(e);
BN_clear_free(d);
BN_clear_free(p);
BN_clear_free(q);
#else
if (!(xfer & 1)) { BN_clear_free(n); BN_clear_free(e); }
if (!(xfer & 2)) { BN_clear_free(p); BN_clear_free(q); }
if (!(xfer & 4)) BN_clear_free(d);
#endif
if (p_minus_1) BN_clear_free(p_minus_1);
if (q_minus_1) BN_clear_free(q_minus_1);
if (dmp1) BN_clear_free(dmp1);
if (dmq1) BN_clear_free(dmq1);
if (iqmp) BN_clear_free(iqmp);
if (ctx) BN_CTX_free(ctx);
BN_clear_free(p_minus_1);
BN_clear_free(q_minus_1);
BN_clear_free(dmp1);
BN_clear_free(dmq1);
BN_clear_free(iqmp);
BN_CTX_free(ctx);
#if OPENSSL_VERSION_NUMBER >= 0x30000000L
if (pctx) { EVP_PKEY_CTX_free(pctx); pctx = NULL; }
if (params_build) { OSSL_PARAM_BLD_free(params_build); params_build = NULL; }
Expand Down
Loading