From adeb8133dd57f380e70a389a89a2ea3ae227f9e2 Mon Sep 17 00:00:00 2001 From: Olga Kornievskaia Date: Mon, 4 Dec 2006 20:22:34 -0500 Subject: [PATCH] rpc: spkm3 update This updates the spkm3 code to bring it up to date with our current understanding of the spkm3 spec. In doing so, we're changing the downcall format used by gssd in the spkm3 case, which will cause an incompatilibity with old userland spkm3 support. Since the old code a) didn't implement the protocol correctly, and b) was never distributed except in the form of some experimental patches from the citi web site, we're assuming this is OK. We do detect the old downcall format and print warning (and fail). We also include a version number in the new downcall format, to be used in the future in case any further change is required. In some more detail: - fix integrity support - removed dependency on NIDs. instead OIDs are used - known OID values for algorithms added. - fixed some context fields and types Signed-off-by: J. Bruce Fields Signed-off-by: Trond Myklebust --- include/linux/sunrpc/gss_spkm3.h | 34 ++++----- net/sunrpc/auth_gss/auth_gss.c | 2 +- net/sunrpc/auth_gss/gss_spkm3_mech.c | 131 +++++++++------------------------ net/sunrpc/auth_gss/gss_spkm3_seal.c | 101 +++++++++++++++++++------ net/sunrpc/auth_gss/gss_spkm3_token.c | 6 +- net/sunrpc/auth_gss/gss_spkm3_unseal.c | 88 +++++++++++----------- 6 files changed, 180 insertions(+), 182 deletions(-) diff --git a/include/linux/sunrpc/gss_spkm3.h b/include/linux/sunrpc/gss_spkm3.h index 2cf3fbb..e3e6a34 100644 --- a/include/linux/sunrpc/gss_spkm3.h +++ b/include/linux/sunrpc/gss_spkm3.h @@ -12,27 +12,19 @@ #include struct spkm3_ctx { - struct xdr_netobj ctx_id; /* per message context id */ - int qop; /* negotiated qop */ + struct xdr_netobj ctx_id; /* per message context id */ + int endtime; /* endtime of the context */ struct xdr_netobj mech_used; unsigned int ret_flags ; - unsigned int req_flags ; - struct xdr_netobj share_key; - int conf_alg; - struct crypto_blkcipher *derived_conf_key; - int intg_alg; - struct crypto_blkcipher *derived_integ_key; - int keyestb_alg; /* alg used to get share_key */ - int owf_alg; /* one way function */ + struct xdr_netobj conf_alg; + struct xdr_netobj derived_conf_key; + struct xdr_netobj intg_alg; + struct xdr_netobj derived_integ_key; }; -/* from openssl/objects.h */ -/* XXX need SEAL_ALG_NONE */ -#define NID_md5 4 -#define NID_dhKeyAgreement 28 -#define NID_des_cbc 31 -#define NID_sha1 64 -#define NID_cast5_cbc 108 +/* OIDs declarations for K-ALG, I-ALG, C-ALG, and OWF-ALG */ +extern const struct xdr_netobj hmac_md5_oid; +extern const struct xdr_netobj cast5_cbc_oid; /* SPKM InnerContext Token types */ @@ -46,11 +38,13 @@ u32 spkm3_make_token(struct spkm3_ctx *ctx, struct xdr_buf * text, struct xdr_ne u32 spkm3_read_token(struct spkm3_ctx *ctx, struct xdr_netobj *read_token, struct xdr_buf *message_buffer, int toktype); #define CKSUMTYPE_RSA_MD5 0x0007 +#define CKSUMTYPE_HMAC_MD5 0x0008 -s32 make_checksum(s32 cksumtype, char *header, int hdrlen, struct xdr_buf *body, - int body_offset, struct xdr_netobj *cksum); +s32 make_spkm3_checksum(s32 cksumtype, struct xdr_netobj *key, char *header, + unsigned int hdrlen, struct xdr_buf *body, + unsigned int body_offset, struct xdr_netobj *cksum); void asn1_bitstring_len(struct xdr_netobj *in, int *enclen, int *zerobits); -int decode_asn1_bitstring(struct xdr_netobj *out, char *in, int enclen, +int decode_asn1_bitstring(struct xdr_netobj *out, char *in, int enclen, int explen); void spkm3_mic_header(unsigned char **hdrbuf, unsigned int *hdrlen, unsigned char *ctxhdr, int elen, int zbit); diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c index d12ee5f..a02ecc1 100644 --- a/net/sunrpc/auth_gss/auth_gss.c +++ b/net/sunrpc/auth_gss/auth_gss.c @@ -68,7 +68,7 @@ static struct rpc_credops gss_credops; #define GSS_CRED_SLACK 1024 /* XXX: unused */ /* length of a krb5 verifier (48), plus data added before arguments when * using integrity (two 4-byte integers): */ -#define GSS_VERF_SLACK 56 +#define GSS_VERF_SLACK 100 /* XXX this define must match the gssd define * as it is passed to gssd to signal the use of diff --git a/net/sunrpc/auth_gss/gss_spkm3_mech.c b/net/sunrpc/auth_gss/gss_spkm3_mech.c index d57f608..4146507 100644 --- a/net/sunrpc/auth_gss/gss_spkm3_mech.c +++ b/net/sunrpc/auth_gss/gss_spkm3_mech.c @@ -82,133 +82,73 @@ simple_get_netobj(const void *p, const void *end, struct xdr_netobj *res) return q; } -static inline const void * -get_key(const void *p, const void *end, struct crypto_blkcipher **res, - int *resalg) -{ - struct xdr_netobj key = { 0 }; - int setkey = 0; - char *alg_name; - - p = simple_get_bytes(p, end, resalg, sizeof(*resalg)); - if (IS_ERR(p)) - goto out_err; - p = simple_get_netobj(p, end, &key); - if (IS_ERR(p)) - goto out_err; - - switch (*resalg) { - case NID_des_cbc: - alg_name = "cbc(des)"; - setkey = 1; - break; - case NID_cast5_cbc: - /* XXXX here in name only, not used */ - alg_name = "cbc(cast5)"; - setkey = 0; /* XXX will need to set to 1 */ - break; - case NID_md5: - if (key.len == 0) { - dprintk("RPC: SPKM3 get_key: NID_md5 zero Key length\n"); - } - alg_name = "md5"; - setkey = 0; - break; - default: - dprintk("gss_spkm3_mech: unsupported algorithm %d\n", *resalg); - goto out_err_free_key; - } - *res = crypto_alloc_blkcipher(alg_name, 0, CRYPTO_ALG_ASYNC); - if (IS_ERR(*res)) { - printk("gss_spkm3_mech: unable to initialize crypto algorthm %s\n", alg_name); - *res = NULL; - goto out_err_free_key; - } - if (setkey) { - if (crypto_blkcipher_setkey(*res, key.data, key.len)) { - printk("gss_spkm3_mech: error setting key for crypto algorthm %s\n", alg_name); - goto out_err_free_tfm; - } - } - - if(key.len > 0) - kfree(key.data); - return p; - -out_err_free_tfm: - crypto_free_blkcipher(*res); -out_err_free_key: - if(key.len > 0) - kfree(key.data); - p = ERR_PTR(-EINVAL); -out_err: - return p; -} - static int gss_import_sec_context_spkm3(const void *p, size_t len, struct gss_ctx *ctx_id) { const void *end = (const void *)((const char *)p + len); struct spkm3_ctx *ctx; + int version; if (!(ctx = kzalloc(sizeof(*ctx), GFP_KERNEL))) goto out_err; + p = simple_get_bytes(p, end, &version, sizeof(version)); + if (IS_ERR(p)) + goto out_err_free_ctx; + if (version != 1) { + dprintk("RPC: unknown spkm3 token format: obsolete nfs-utils?\n"); + goto out_err_free_ctx; + } + p = simple_get_netobj(p, end, &ctx->ctx_id); if (IS_ERR(p)) goto out_err_free_ctx; - p = simple_get_bytes(p, end, &ctx->qop, sizeof(ctx->qop)); + p = simple_get_bytes(p, end, &ctx->endtime, sizeof(ctx->endtime)); if (IS_ERR(p)) goto out_err_free_ctx_id; p = simple_get_netobj(p, end, &ctx->mech_used); if (IS_ERR(p)) - goto out_err_free_mech; + goto out_err_free_ctx_id; p = simple_get_bytes(p, end, &ctx->ret_flags, sizeof(ctx->ret_flags)); if (IS_ERR(p)) goto out_err_free_mech; - p = simple_get_bytes(p, end, &ctx->req_flags, sizeof(ctx->req_flags)); + p = simple_get_netobj(p, end, &ctx->conf_alg); if (IS_ERR(p)) goto out_err_free_mech; - p = simple_get_netobj(p, end, &ctx->share_key); - if (IS_ERR(p)) - goto out_err_free_s_key; - - p = get_key(p, end, &ctx->derived_conf_key, &ctx->conf_alg); + p = simple_get_netobj(p, end, &ctx->derived_conf_key); if (IS_ERR(p)) - goto out_err_free_s_key; + goto out_err_free_conf_alg; - p = get_key(p, end, &ctx->derived_integ_key, &ctx->intg_alg); + p = simple_get_netobj(p, end, &ctx->intg_alg); if (IS_ERR(p)) - goto out_err_free_key1; + goto out_err_free_conf_key; - p = simple_get_bytes(p, end, &ctx->keyestb_alg, sizeof(ctx->keyestb_alg)); + p = simple_get_netobj(p, end, &ctx->derived_integ_key); if (IS_ERR(p)) - goto out_err_free_key2; - - p = simple_get_bytes(p, end, &ctx->owf_alg, sizeof(ctx->owf_alg)); - if (IS_ERR(p)) - goto out_err_free_key2; + goto out_err_free_intg_alg; if (p != end) - goto out_err_free_key2; + goto out_err_free_intg_key; ctx_id->internal_ctx_id = ctx; dprintk("Successfully imported new spkm context.\n"); return 0; -out_err_free_key2: - crypto_free_blkcipher(ctx->derived_integ_key); -out_err_free_key1: - crypto_free_blkcipher(ctx->derived_conf_key); -out_err_free_s_key: - kfree(ctx->share_key.data); +out_err_free_intg_key: + kfree(ctx->derived_integ_key.data); +out_err_free_intg_alg: + kfree(ctx->intg_alg.data); +out_err_free_conf_key: + kfree(ctx->derived_conf_key.data); +out_err_free_conf_alg: + kfree(ctx->conf_alg.data); out_err_free_mech: kfree(ctx->mech_used.data); out_err_free_ctx_id: @@ -220,13 +160,16 @@ out_err: } static void -gss_delete_sec_context_spkm3(void *internal_ctx) { +gss_delete_sec_context_spkm3(void *internal_ctx) +{ struct spkm3_ctx *sctx = internal_ctx; - crypto_free_blkcipher(sctx->derived_integ_key); - crypto_free_blkcipher(sctx->derived_conf_key); - kfree(sctx->share_key.data); + kfree(sctx->derived_integ_key.data); + kfree(sctx->intg_alg.data); + kfree(sctx->derived_conf_key.data); + kfree(sctx->conf_alg.data); kfree(sctx->mech_used.data); + kfree(sctx->ctx_id.data); kfree(sctx); } @@ -238,7 +181,6 @@ gss_verify_mic_spkm3(struct gss_ctx *ctx, u32 maj_stat = 0; struct spkm3_ctx *sctx = ctx->internal_ctx_id; - dprintk("RPC: gss_verify_mic_spkm3 calling spkm3_read_token\n"); maj_stat = spkm3_read_token(sctx, checksum, signbuf, SPKM_MIC_TOK); dprintk("RPC: gss_verify_mic_spkm3 returning %d\n", maj_stat); @@ -253,10 +195,9 @@ gss_get_mic_spkm3(struct gss_ctx *ctx, u32 err = 0; struct spkm3_ctx *sctx = ctx->internal_ctx_id; - dprintk("RPC: gss_get_mic_spkm3\n"); - err = spkm3_make_token(sctx, message_buffer, - message_token, SPKM_MIC_TOK); + message_token, SPKM_MIC_TOK); + dprintk("RPC: gss_get_mic_spkm3 returning %d\n", err); return err; } diff --git a/net/sunrpc/auth_gss/gss_spkm3_seal.c b/net/sunrpc/auth_gss/gss_spkm3_seal.c index 18c7862..b179d58 100644 --- a/net/sunrpc/auth_gss/gss_spkm3_seal.c +++ b/net/sunrpc/auth_gss/gss_spkm3_seal.c @@ -39,11 +39,17 @@ #include #include #include +#include +#include +#include #ifdef RPC_DEBUG # define RPCDBG_FACILITY RPCDBG_AUTH #endif +const struct xdr_netobj hmac_md5_oid = { 8, "\x2B\x06\x01\x05\x05\x08\x01\x01"}; +const struct xdr_netobj cast5_cbc_oid = {9, "\x2A\x86\x48\x86\xF6\x7D\x07\x42\x0A"}; + /* * spkm3_make_token() * @@ -66,29 +72,23 @@ spkm3_make_token(struct spkm3_ctx *ctx, int ctxelen = 0, ctxzbit = 0; int md5elen = 0, md5zbit = 0; - dprintk("RPC: spkm3_make_token\n"); - now = jiffies; if (ctx->ctx_id.len != 16) { dprintk("RPC: spkm3_make_token BAD ctx_id.len %d\n", - ctx->ctx_id.len); + ctx->ctx_id.len); goto out_err; } - - switch (ctx->intg_alg) { - case NID_md5: - checksum_type = CKSUMTYPE_RSA_MD5; - break; - default: - dprintk("RPC: gss_spkm3_seal: ctx->signalg %d not" - " supported\n", ctx->intg_alg); - goto out_err; - } - /* XXX since we don't support WRAP, perhaps we don't care... */ - if (ctx->conf_alg != NID_cast5_cbc) { - dprintk("RPC: gss_spkm3_seal: ctx->sealalg %d not supported\n", - ctx->conf_alg); + + if (!g_OID_equal(&ctx->intg_alg, &hmac_md5_oid)) { + dprintk("RPC: gss_spkm3_seal: unsupported I-ALG algorithm." + "only support hmac-md5 I-ALG.\n"); + goto out_err; + } else + checksum_type = CKSUMTYPE_HMAC_MD5; + + if (!g_OID_equal(&ctx->conf_alg, &cast5_cbc_oid)) { + dprintk("RPC: gss_spkm3_seal: unsupported C-ALG algorithm\n"); goto out_err; } @@ -96,10 +96,10 @@ spkm3_make_token(struct spkm3_ctx *ctx, /* Calculate checksum over the mic-header */ asn1_bitstring_len(&ctx->ctx_id, &ctxelen, &ctxzbit); spkm3_mic_header(&mic_hdr.data, &mic_hdr.len, ctx->ctx_id.data, - ctxelen, ctxzbit); - - if (make_checksum(checksum_type, mic_hdr.data, mic_hdr.len, - text, 0, &md5cksum)) + ctxelen, ctxzbit); + if (make_spkm3_checksum(checksum_type, &ctx->derived_integ_key, + (char *)mic_hdr.data, mic_hdr.len, + text, 0, &md5cksum)) goto out_err; asn1_bitstring_len(&md5cksum, &md5elen, &md5zbit); @@ -121,7 +121,66 @@ spkm3_make_token(struct spkm3_ctx *ctx, return GSS_S_COMPLETE; out_err: + if (md5cksum.data) + kfree(md5cksum.data); + token->data = NULL; token->len = 0; return GSS_S_FAILURE; } + +static int +spkm3_checksummer(struct scatterlist *sg, void *data) +{ + struct hash_desc *desc = data; + + return crypto_hash_update(desc, sg, sg->length); +} + +/* checksum the plaintext data and hdrlen bytes of the token header */ +s32 +make_spkm3_checksum(s32 cksumtype, struct xdr_netobj *key, char *header, + unsigned int hdrlen, struct xdr_buf *body, + unsigned int body_offset, struct xdr_netobj *cksum) +{ + char *cksumname; + struct hash_desc desc; /* XXX add to ctx? */ + struct scatterlist sg[1]; + int err; + + switch (cksumtype) { + case CKSUMTYPE_HMAC_MD5: + cksumname = "md5"; + break; + default: + dprintk("RPC: spkm3_make_checksum:" + " unsupported checksum %d", cksumtype); + return GSS_S_FAILURE; + } + + if (key->data == NULL || key->len <= 0) return GSS_S_FAILURE; + + desc.tfm = crypto_alloc_hash(cksumname, 0, CRYPTO_ALG_ASYNC); + if (IS_ERR(desc.tfm)) + return GSS_S_FAILURE; + cksum->len = crypto_hash_digestsize(desc.tfm); + desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; + + err = crypto_hash_setkey(desc.tfm, key->data, key->len); + if (err) + goto out; + + sg_set_buf(sg, header, hdrlen); + crypto_hash_update(&desc, sg, 1); + + xdr_process_buf(body, body_offset, body->len - body_offset, + spkm3_checksummer, &desc); + crypto_hash_final(&desc, cksum->data); + +out: + crypto_free_hash(desc.tfm); + + return err ? GSS_S_FAILURE : 0; +} + +EXPORT_SYMBOL(make_spkm3_checksum); diff --git a/net/sunrpc/auth_gss/gss_spkm3_token.c b/net/sunrpc/auth_gss/gss_spkm3_token.c index 854a983..35188b6 100644 --- a/net/sunrpc/auth_gss/gss_spkm3_token.c +++ b/net/sunrpc/auth_gss/gss_spkm3_token.c @@ -172,10 +172,10 @@ spkm3_mic_header(unsigned char **hdrbuf, unsigned int *hdrlen, unsigned char *ct *(u8 *)hptr++ = zbit; memcpy(hptr, ctxdata, elen); hptr += elen; - *hdrlen = hptr - top; + *hdrlen = hptr - top; } - -/* + +/* * spkm3_mic_innercontext_token() * * *tokp points to the beginning of the SPKM_MIC token described diff --git a/net/sunrpc/auth_gss/gss_spkm3_unseal.c b/net/sunrpc/auth_gss/gss_spkm3_unseal.c index 544eb6f..e54581c 100644 --- a/net/sunrpc/auth_gss/gss_spkm3_unseal.c +++ b/net/sunrpc/auth_gss/gss_spkm3_unseal.c @@ -54,66 +54,70 @@ spkm3_read_token(struct spkm3_ctx *ctx, 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; + 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); - - 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); + 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; } + /* XXX: need to add expiration and sequencing */ ret = GSS_S_COMPLETE; out: -- 2.7.4