/*
* spkm3_read_token()
*
* only SPKM_MIC_TOK with md5 intg-alg is supported
*/
u32
spkm3_read_token(struct spkm3_ctx *ctx,
struct xdr_netobj *read_token, /* checksum */
struct xdr_buf *message_buffer, /* signbuf */
int toktype)
{
s32 code;
struct xdr_netobj wire_cksum = {.len =0, .data = NULL};
struct xdr_netobj md5cksum = {.len = 0, .data = NULL};
unsigned char *ptr = (unsigned char *)read_token->data;
unsigned char *cksum;
int bodysize, md5elen;
int mic_hdrlen;
u32 ret = GSS_S_DEFECTIVE_TOKEN;
dprintk("RPC: spkm3_read_token read_token->len %d\n", read_token->len);
if (g_verify_token_header((struct xdr_netobj *) &ctx->mech_used,
&bodysize, &ptr, read_token->len))
goto out;
/* decode the token */
if (toktype == SPKM_MIC_TOK) {
if ((ret = spkm3_verify_mic_token(&ptr, &mic_hdrlen, &cksum)))
goto out;
if (*cksum++ != 0x03) {
dprintk("RPC: spkm3_read_token BAD checksum type\n");
goto out;
}
md5elen = *cksum++;
cksum++; /* move past the zbit */
if(!decode_asn1_bitstring(&wire_cksum, cksum, md5elen - 1, 16))
goto out;
/* HARD CODED FOR MD5 */
/* compute the checksum of the message.
* ptr + 2 = start of header piece of checksum
* mic_hdrlen + 2 = length of header piece of checksum
*/
ret = GSS_S_DEFECTIVE_TOKEN;
code = make_checksum(CKSUMTYPE_RSA_MD5, ptr + 2,
mic_hdrlen + 2,
message_buffer, 0, &md5cksum);
if (code)
goto out;
dprintk("RPC: spkm3_read_token: digest wire_cksum.len %d:\n",
wire_cksum.len);
dprintk(" md5cksum.data\n");
print_hexl((u32 *) md5cksum.data, 16, 0);
dprintk(" cksum.data:\n");
print_hexl((u32 *) wire_cksum.data, wire_cksum.len, 0);
ret = GSS_S_BAD_SIG;
code = memcmp(md5cksum.data, wire_cksum.data, wire_cksum.len);
if (code)
goto out;
} else {
dprintk("RPC: BAD or UNSUPPORTED SPKM3 token type: %d\n",toktype);
goto out;
}
/* XXX: need to add expiration and sequencing */
ret = GSS_S_COMPLETE;
out:
kfree(md5cksum.data);
kfree(wire_cksum.data);
return ret;
}
u32
spkm3_verify_mic_token(unsigned char **tokp, int *mic_hdrlen, unsigned char **cksum)
{
struct xdr_netobj spkm3_ctx_id = {.len =0, .data = NULL};
unsigned char *ptr = *tokp;
int ctxelen;
u32 ret = GSS_S_DEFECTIVE_TOKEN;
/* spkm3 innercontext token preamble */
if ((ptr[0] != 0xa4) || (ptr[2] != 0x30)) {
dprintk("RPC: BAD SPKM ictoken preamble\n");
goto out;
}
*mic_hdrlen = ptr[3];
/* token type */
if ((ptr[4] != 0x02) || (ptr[5] != 0x02)) {
dprintk("RPC: BAD asn1 SPKM3 token type\n");
goto out;
}
/* only support SPKM_MIC_TOK */
if((ptr[6] != 0x01) || (ptr[7] != 0x01)) {
dprintk("RPC: ERROR unsupported SPKM3 token \n");
goto out;
}
/* contextid */
if (ptr[8] != 0x03) {
dprintk("RPC: BAD SPKM3 asn1 context-id type\n");
goto out;
}
ctxelen = ptr[9];
if (ctxelen > 17) { /* length includes asn1 zbit octet */
dprintk("RPC: BAD SPKM3 contextid len %d\n", ctxelen);
goto out;
}
/* ignore ptr[10] */
if(!decode_asn1_bitstring(&spkm3_ctx_id, &ptr[11], ctxelen - 1, 16))
goto out;
/*
* in the current implementation: the optional int-alg is not present
* so the default int-alg (md5) is used the optional snd-seq field is
* also not present
*/
if (*mic_hdrlen != 6 + ctxelen) {
dprintk("RPC: BAD SPKM_ MIC_TOK header len %d: we only "
"support default int-alg (should be absent) "
"and do not support snd-seq\n", *mic_hdrlen);
goto out;
}
/* checksum */
*cksum = (&ptr[10] + ctxelen); /* ctxelen includes ptr[10] */
ret = GSS_S_COMPLETE;
out:
kfree(spkm3_ctx_id.data);
return ret;
}
/*
* spkm3_read_token()
*
* only SPKM_MIC_TOK with md5 intg-alg is supported
*/
u32
spkm3_read_token(struct spkm3_ctx *ctx,
struct xdr_netobj *read_token, /* checksum */
struct xdr_buf *message_buffer, /* signbuf */
int toktype)
{
s32 checksum_type;
s32 code;
struct xdr_netobj wire_cksum = {.len =0, .data = NULL};
char cksumdata[16];
struct xdr_netobj md5cksum = {.len = 0, .data = cksumdata};
unsigned char *ptr = (unsigned char *)read_token->data;
unsigned char *cksum;
int bodysize, md5elen;
int mic_hdrlen;
u32 ret = GSS_S_DEFECTIVE_TOKEN;
if (g_verify_token_header((struct xdr_netobj *) &ctx->mech_used,
&bodysize, &ptr, read_token->len))
goto out;
/* decode the token */
if (toktype != SPKM_MIC_TOK) {
dprintk("RPC: BAD SPKM3 token type: %d\n", toktype);
goto out;
}
if ((ret = spkm3_verify_mic_token(&ptr, &mic_hdrlen, &cksum)))
goto out;
if (*cksum++ != 0x03) {
dprintk("RPC: spkm3_read_token BAD checksum type\n");
goto out;
}
md5elen = *cksum++;
cksum++; /* move past the zbit */
if (!decode_asn1_bitstring(&wire_cksum, cksum, md5elen - 1, 16))
goto out;
/* HARD CODED FOR MD5 */
/* compute the checksum of the message.
* ptr + 2 = start of header piece of checksum
* mic_hdrlen + 2 = length of header piece of checksum
*/
ret = GSS_S_DEFECTIVE_TOKEN;
if (!g_OID_equal(&ctx->intg_alg, &hmac_md5_oid)) {
dprintk("RPC: gss_spkm3_seal: unsupported I-ALG "
"algorithm\n");
goto out;
}
checksum_type = CKSUMTYPE_HMAC_MD5;
code = make_spkm3_checksum(checksum_type,
&ctx->derived_integ_key, ptr + 2, mic_hdrlen + 2,
message_buffer, 0, &md5cksum);
if (code)
goto out;
ret = GSS_S_BAD_SIG;
code = memcmp(md5cksum.data, wire_cksum.data, wire_cksum.len);
if (code) {
dprintk("RPC: bad MIC checksum\n");
goto out;
}
ret = GSS_S_COMPLETE;
out:
kfree(wire_cksum.data);
return ret;
}
