From 76f0fb917087893edba7463e6981f61d25f2bf07 Mon Sep 17 00:00:00 2001 From: Stefan Metzmacher Date: Mon, 17 Aug 2009 09:46:19 +0200 Subject: [PATCH] gsskrb5: fix ec and padding handling in _gssapi_wrap_cfx_iov() metze Signed-off-by: Love Hornquist Astrand --- lib/gssapi/krb5/cfx.c | 124 +++++++++++++++++++++++++++++------------- 1 file changed, 85 insertions(+), 39 deletions(-) diff --git a/lib/gssapi/krb5/cfx.c b/lib/gssapi/krb5/cfx.c index ac1760408..ced664904 100755 --- a/lib/gssapi/krb5/cfx.c +++ b/lib/gssapi/krb5/cfx.c @@ -285,44 +285,94 @@ _gssapi_wrap_cfx_iov(OM_uint32 *minor_status, gss_iov_buffer_desc *header, *trailer, *padding; size_t gsshsize, k5hsize; size_t gsstsize, k5tsize; - size_t i, padlength, rrc = 0, ec = 0; + size_t i, rrc = 0, ec = 0; gss_cfx_wrap_token token; krb5_error_code ret; int32_t seq_number; unsigned usage; krb5_crypto_iov *data = NULL; - int paddingoffset = 0; - + header = _gk_find_buffer(iov, iov_count, GSS_IOV_BUFFER_TYPE_HEADER); if (header == NULL) { *minor_status = EINVAL; return GSS_S_FAILURE; } - krb5_crypto_length(context, ctx->crypto, KRB5_CRYPTO_TYPE_PADDING, &padlength); - padding = _gk_find_buffer(iov, iov_count, GSS_IOV_BUFFER_TYPE_PADDING); - if (padlength != 0 && padding == NULL) { - *minor_status = EINVAL; - return GSS_S_FAILURE; + if (padding != NULL) { + padding->buffer.length = 0; } trailer = _gk_find_buffer(iov, iov_count, GSS_IOV_BUFFER_TYPE_TRAILER); + major_status = _gk_verify_buffers(minor_status, ctx, header, padding, trailer); + if (major_status != GSS_S_COMPLETE) { + return major_status; + } + if (conf_req_flag) { - ec = padlength; + size_t k5psize = 0; + size_t k5pbase = 0; + size_t k5bsize = 0; + size_t size = 0; - krb5_crypto_length(context, ctx->crypto, KRB5_CRYPTO_TYPE_TRAILER, &k5tsize); - krb5_crypto_length(context, ctx->crypto, KRB5_CRYPTO_TYPE_HEADER, &k5hsize); + for (i = 0; i < iov_count; i++) { + switch (GSS_IOV_BUFFER_TYPE(iov[i].type)) { + case GSS_IOV_BUFFER_TYPE_DATA: + size += iov[i].buffer.length; + break; + default: + break; + } + } - gsshsize = k5hsize + sizeof(*token); - gsstsize = k5tsize + sizeof(*token); /* encrypted token stored in trailer */ + size += sizeof(gss_cfx_wrap_token_desc); + *minor_status = krb5_crypto_length(context, ctx->crypto, + KRB5_CRYPTO_TYPE_HEADER, + &k5hsize); + if (*minor_status) + return GSS_S_FAILURE; + + *minor_status = krb5_crypto_length(context, ctx->crypto, + KRB5_CRYPTO_TYPE_TRAILER, + &k5tsize); + if (*minor_status) + return GSS_S_FAILURE; + + *minor_status = krb5_crypto_length(context, ctx->crypto, + KRB5_CRYPTO_TYPE_PADDING, + &k5pbase); + if (*minor_status) + return GSS_S_FAILURE; + + if (k5pbase > 1) { + k5psize = k5pbase - (size % k5pbase); + } else { + k5psize = 0; + } + + if (k5psize == 0 && IS_DCE_STYLE(ctx)) { + *minor_status = krb5_crypto_getblocksize(context, ctx->crypto, + &k5bsize); + if (*minor_status) + return GSS_S_FAILURE; + ec = k5bsize; + } else { + ec = k5psize; + } + + gsshsize = sizeof(gss_cfx_wrap_token_desc) + k5hsize; + gsstsize = sizeof(gss_cfx_wrap_token_desc) + ec + k5tsize; } else { + k5hsize = 0; + *minor_status = krb5_crypto_length(context, ctx->crypto, + KRB5_CRYPTO_TYPE_CHECKSUM, + &k5tsize); + if (*minor_status) + return GSS_S_FAILURE; - krb5_crypto_length(context, ctx->crypto, KRB5_CRYPTO_TYPE_CHECKSUM, &k5tsize); - - gsshsize = sizeof(*token); + gsshsize = sizeof(gss_cfx_wrap_token_desc); gsstsize = k5tsize; } @@ -389,8 +439,8 @@ _gssapi_wrap_cfx_iov(OM_uint32 *minor_status, * used to encode the size (in bytes) of the random filler. */ token->Flags |= CFXSealed; - token->EC[0] = (padlength >> 8) & 0xFF; - token->EC[1] = (padlength >> 0) & 0xFF; + token->EC[0] = (ec >> 8) & 0xFF; + token->EC[1] = (ec >> 0) & 0xFF; } else { /* @@ -441,15 +491,15 @@ _gssapi_wrap_cfx_iov(OM_uint32 *minor_status, /* plain packet: - {"header" | encrypt(plaintext-data | padding | E"header")} + {"header" | encrypt(plaintext-data | ec-padding | E"header")} Expanded, this is with with RRC = 0: - {"header" | krb5-header | plaintext-data | padding | E"header" | krb5-trailer } + {"header" | krb5-header | plaintext-data | ec-padding | E"header" | krb5-trailer } - In DCE-RPC mode == no trailer: RRC = gss "trailer" == length(padding | E"header" | krb5-trailer) + In DCE-RPC mode == no trailer: RRC = gss "trailer" == length(ec-padding | E"header" | krb5-trailer) - {"header" | padding | E"header" | krb5-trailer | krb5-header | plaintext-data } + {"header" | ec-padding | E"header" | krb5-trailer | krb5-header | plaintext-data } */ i = 0; @@ -462,10 +512,6 @@ _gssapi_wrap_cfx_iov(OM_uint32 *minor_status, case GSS_IOV_BUFFER_TYPE_DATA: data[i].flags = KRB5_CRYPTO_TYPE_DATA; break; - case GSS_IOV_BUFFER_TYPE_PADDING: - data[i].flags = KRB5_CRYPTO_TYPE_PADDING; - paddingoffset = i; - break; case GSS_IOV_BUFFER_TYPE_SIGN_ONLY: data[i].flags = KRB5_CRYPTO_TYPE_SIGN_ONLY; break; @@ -483,8 +529,6 @@ _gssapi_wrap_cfx_iov(OM_uint32 *minor_status, * ciphertext. */ - /* XXX KRB5_CRYPTO_TYPE_PADDING */ - /* encrypted CFX header in trailer (or after the header if in DCE mode). Copy in header into E"header" */ @@ -492,15 +536,16 @@ _gssapi_wrap_cfx_iov(OM_uint32 *minor_status, if (trailer) data[i].data.data = trailer->buffer.value; else - data[i].data.data = ((uint8_t *)header->buffer.value) + header->buffer.length - k5hsize - k5tsize - sizeof(*token); + data[i].data.data = ((uint8_t *)header->buffer.value) + sizeof(*token); - data[i].data.length = sizeof(*token); - memcpy(data[i].data.data, token, sizeof(*token)); + data[i].data.length = ec + sizeof(*token); + memset(data[i].data.data, 0xFF, ec); + memcpy(((uint8_t *)data[i].data.data) + ec, token, sizeof(*token)); i++; /* Kerberos trailer comes after the gss trailer */ data[i].flags = KRB5_CRYPTO_TYPE_TRAILER; - data[i].data.data = ((uint8_t *)data[i-1].data.data) + sizeof(*token); + data[i].data.data = ((uint8_t *)data[i-1].data.data) + ec + sizeof(*token); data[i].data.length = k5tsize; i++; @@ -516,9 +561,6 @@ _gssapi_wrap_cfx_iov(OM_uint32 *minor_status, token->RRC[1] = (rrc >> 0) & 0xFF; } - if (paddingoffset) - padding->buffer.length = data[paddingoffset].data.length; - } else { /* plain packet: @@ -532,7 +574,6 @@ _gssapi_wrap_cfx_iov(OM_uint32 *minor_status, for (i = 0; i < iov_count; i++) { switch (GSS_IOV_BUFFER_TYPE(iov[i].type)) { case GSS_IOV_BUFFER_TYPE_DATA: - case GSS_IOV_BUFFER_TYPE_PADDING: data[i].flags = KRB5_CRYPTO_TYPE_DATA; break; case GSS_IOV_BUFFER_TYPE_SIGN_ONLY: @@ -548,12 +589,17 @@ _gssapi_wrap_cfx_iov(OM_uint32 *minor_status, data[i].flags = KRB5_CRYPTO_TYPE_DATA; data[i].data.data = header->buffer.value; - data[i].data.length = header->buffer.length; + data[i].data.length = sizeof(gss_cfx_wrap_token_desc); i++; data[i].flags = KRB5_CRYPTO_TYPE_CHECKSUM; - data[i].data.data = trailer->buffer.value; - data[i].data.length = trailer->buffer.length; + if (trailer) { + data[i].data.data = trailer->buffer.value; + } else { + data[i].data.data = (uint8_t *)header->buffer.value + + sizeof(gss_cfx_wrap_token_desc); + } + data[i].data.length = k5tsize; i++; ret = krb5_create_checksum_iov(context, ctx->crypto, usage, data, i, NULL);