From fffdaef2eb4a7333952e55cf97f1fc0fcc35f981 Mon Sep 17 00:00:00 2001 From: Kevin Coffman Date: Wed, 17 Mar 2010 13:03:06 -0400 Subject: gss_krb5: Add support for rc4-hmac encryption Add necessary changes to add kernel support for the rc4-hmac Kerberos encryption type used by Microsoft and described in rfc4757. Signed-off-by: Kevin Coffman Signed-off-by: Steve Dickson Signed-off-by: Trond Myklebust --- net/sunrpc/auth_gss/gss_krb5_wrap.c | 66 +++++++++++++++++++++++++++++-------- 1 file changed, 53 insertions(+), 13 deletions(-) (limited to 'net/sunrpc/auth_gss/gss_krb5_wrap.c') diff --git a/net/sunrpc/auth_gss/gss_krb5_wrap.c b/net/sunrpc/auth_gss/gss_krb5_wrap.c index 383db89..2763e3e 100644 --- a/net/sunrpc/auth_gss/gss_krb5_wrap.c +++ b/net/sunrpc/auth_gss/gss_krb5_wrap.c @@ -232,9 +232,26 @@ gss_wrap_kerberos_v1(struct krb5_ctx *kctx, int offset, seq_send, ptr + GSS_KRB5_TOK_HDR_LEN, ptr + 8))) return GSS_S_FAILURE; - if (gss_encrypt_xdr_buf(kctx->enc, buf, offset + headlen - conflen, - pages)) - return GSS_S_FAILURE; + if (kctx->enctype == ENCTYPE_ARCFOUR_HMAC) { + struct crypto_blkcipher *cipher; + int err; + cipher = crypto_alloc_blkcipher(kctx->gk5e->encrypt_name, 0, + CRYPTO_ALG_ASYNC); + if (IS_ERR(cipher)) + return GSS_S_FAILURE; + + krb5_rc4_setup_enc_key(kctx, cipher, seq_send); + + err = gss_encrypt_xdr_buf(cipher, buf, + offset + headlen - conflen, pages); + crypto_free_blkcipher(cipher); + if (err) + return GSS_S_FAILURE; + } else { + if (gss_encrypt_xdr_buf(kctx->enc, buf, + offset + headlen - conflen, pages)) + return GSS_S_FAILURE; + } return (kctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE; } @@ -291,8 +308,37 @@ gss_unwrap_kerberos_v1(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf) */ crypt_offset = ptr + (GSS_KRB5_TOK_HDR_LEN + kctx->gk5e->cksumlength) - (unsigned char *)buf->head[0].iov_base; - if (gss_decrypt_xdr_buf(kctx->enc, buf, crypt_offset)) - return GSS_S_DEFECTIVE_TOKEN; + + /* + * Need plaintext seqnum to derive encryption key for arcfour-hmac + */ + if (krb5_get_seq_num(kctx, ptr + GSS_KRB5_TOK_HDR_LEN, + ptr + 8, &direction, &seqnum)) + return GSS_S_BAD_SIG; + + if ((kctx->initiate && direction != 0xff) || + (!kctx->initiate && direction != 0)) + return GSS_S_BAD_SIG; + + if (kctx->enctype == ENCTYPE_ARCFOUR_HMAC) { + struct crypto_blkcipher *cipher; + int err; + + cipher = crypto_alloc_blkcipher(kctx->gk5e->encrypt_name, 0, + CRYPTO_ALG_ASYNC); + if (IS_ERR(cipher)) + return GSS_S_FAILURE; + + krb5_rc4_setup_enc_key(kctx, cipher, seqnum); + + err = gss_decrypt_xdr_buf(cipher, buf, crypt_offset); + crypto_free_blkcipher(cipher); + if (err) + return GSS_S_DEFECTIVE_TOKEN; + } else { + if (gss_decrypt_xdr_buf(kctx->enc, buf, crypt_offset)) + return GSS_S_DEFECTIVE_TOKEN; + } if (kctx->gk5e->keyed_cksum) cksumkey = kctx->cksum; @@ -316,14 +362,6 @@ gss_unwrap_kerberos_v1(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf) /* do sequencing checks */ - if (krb5_get_seq_num(kctx, ptr + GSS_KRB5_TOK_HDR_LEN, - ptr + 8, &direction, &seqnum)) - return GSS_S_BAD_SIG; - - if ((kctx->initiate && direction != 0xff) || - (!kctx->initiate && direction != 0)) - return GSS_S_BAD_SIG; - /* Copy the data back to the right position. XXX: Would probably be * better to copy and encrypt at the same time. */ @@ -521,6 +559,7 @@ gss_wrap_kerberos(struct gss_ctx *gctx, int offset, BUG(); case ENCTYPE_DES_CBC_RAW: case ENCTYPE_DES3_CBC_RAW: + case ENCTYPE_ARCFOUR_HMAC: return gss_wrap_kerberos_v1(kctx, offset, buf, pages); case ENCTYPE_AES128_CTS_HMAC_SHA1_96: case ENCTYPE_AES256_CTS_HMAC_SHA1_96: @@ -538,6 +577,7 @@ gss_unwrap_kerberos(struct gss_ctx *gctx, int offset, struct xdr_buf *buf) BUG(); case ENCTYPE_DES_CBC_RAW: case ENCTYPE_DES3_CBC_RAW: + case ENCTYPE_ARCFOUR_HMAC: return gss_unwrap_kerberos_v1(kctx, offset, buf); case ENCTYPE_AES128_CTS_HMAC_SHA1_96: case ENCTYPE_AES256_CTS_HMAC_SHA1_96: -- cgit v1.1