commit 80833cb9e6d3f6a1d61b168af91c26c5f7a07178 Author: tlyu tlyu@dc483132-0cff-0310-8789-dd5450dbe970 Date: Tue Jul 20 22:28:35 2010 +0000

ticket: 6738 version_fixed: 1.8.3 status: resolved

pull up r24137 from trunk

------------------------------------------------------------------------ r24137 | ghudson | 2010-06-14 16:46:27 -0400 (Mon, 14 Jun 2010) | 7 lines

ticket: 6738 target_version: 1.8.3 tags: pullup

In PKINIT, notice if DH_compute_key() returns a value less than the buffer size, and pad it on the left if so.

git-svn-id: svn://anonsvn.mit.edu/krb5/branches/krb5-1-8@24194 dc483132-0cff-0310-8789-dd5450dbe970

src/plugins/preauth/pkinit/pkinit_crypto_openssl.c | 20 ++++++++++++++++++-- 1 files changed, 18 insertions(+), 2 deletions(-) --- diff --git a/src/plugins/preauth/pkinit/pkinit_crypto_openssl.c b/src/plugins/preauth/pkinit/pkinit_crypto_openssl.c index d000466..af09d69 100644 --- a/src/plugins/preauth/pkinit/pkinit_crypto_openssl.c +++ b/src/plugins/preauth/pkinit/pkinit_crypto_openssl.c @@ -2092,6 +2092,22 @@ cleanup: return retval; }

+/* Call DH_compute_key() and ensure that we left-pad short results instead of + * leaving junk bytes at the end of the buffer. */ +static void +compute_dh(unsigned char *buf, int size, BIGNUM *server_pub_key, DH *dh) +{ + int len, pad; + + len = DH_compute_key(buf, server_pub_key, dh); + assert(len >= 0 && len <= size); + if (len < size) { + pad = size - len; + memmove(buf + pad, buf, len); + memset(buf, 0, pad); + } +} + krb5_error_code client_create_dh(krb5_context context, pkinit_plg_crypto_context plg_cryptoctx, @@ -2243,7 +2259,7 @@ client_process_dh(krb5_context context, if ((server_pub_key = ASN1_INTEGER_to_BN(pub_key, NULL)) == NULL) goto cleanup;

- DH_compute_key(*client_key, server_pub_key, cryptoctx->dh); + compute_dh(*client_key, *client_key_len, server_pub_key, cryptoctx->dh); #ifdef DEBUG_DH print_pubkey(server_pub_key, "server's pub_key="); pkiDebug("client secret key (%d)= ", *client_key_len); @@ -2378,7 +2394,7 @@ server_process_dh(krb5_context context, *server_key_len = DH_size(dh_server); if ((*server_key = malloc(*server_key_len)) == NULL) goto cleanup; - DH_compute_key(*server_key, dh->pub_key, dh_server); + compute_dh(*server_key, *server_key_len, dh->pub_key, dh_server);

#ifdef DEBUG_DH print_dh(dh_server, "client&server's DH params\n");