diff options
Diffstat (limited to 'net/sunrpc/auth_gss/gss_krb5_mech.c')
| -rw-r--r-- | net/sunrpc/auth_gss/gss_krb5_mech.c | 654 |
1 files changed, 654 insertions, 0 deletions
diff --git a/net/sunrpc/auth_gss/gss_krb5_mech.c b/net/sunrpc/auth_gss/gss_krb5_mech.c new file mode 100644 index 000000000..1c092b05c --- /dev/null +++ b/net/sunrpc/auth_gss/gss_krb5_mech.c @@ -0,0 +1,654 @@ +// SPDX-License-Identifier: BSD-3-Clause +/* + * linux/net/sunrpc/gss_krb5_mech.c + * + * Copyright (c) 2001-2008 The Regents of the University of Michigan. + * All rights reserved. + * + * Andy Adamson <andros@umich.edu> + * J. Bruce Fields <bfields@umich.edu> + */ + +#include <crypto/hash.h> +#include <crypto/skcipher.h> +#include <linux/err.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/sunrpc/auth.h> +#include <linux/sunrpc/gss_krb5.h> +#include <linux/sunrpc/xdr.h> +#include <linux/sunrpc/gss_krb5_enctypes.h> + +#include "auth_gss_internal.h" + +#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) +# define RPCDBG_FACILITY RPCDBG_AUTH +#endif + +static struct gss_api_mech gss_kerberos_mech; /* forward declaration */ + +static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = { +#ifndef CONFIG_SUNRPC_DISABLE_INSECURE_ENCTYPES + /* + * DES (All DES enctypes are mapped to the same gss functionality) + */ + { + .etype = ENCTYPE_DES_CBC_RAW, + .ctype = CKSUMTYPE_RSA_MD5, + .name = "des-cbc-crc", + .encrypt_name = "cbc(des)", + .cksum_name = "md5", + .encrypt = krb5_encrypt, + .decrypt = krb5_decrypt, + .mk_key = NULL, + .signalg = SGN_ALG_DES_MAC_MD5, + .sealalg = SEAL_ALG_DES, + .keybytes = 7, + .keylength = 8, + .blocksize = 8, + .conflen = 8, + .cksumlength = 8, + .keyed_cksum = 0, + }, +#endif /* CONFIG_SUNRPC_DISABLE_INSECURE_ENCTYPES */ + /* + * 3DES + */ + { + .etype = ENCTYPE_DES3_CBC_RAW, + .ctype = CKSUMTYPE_HMAC_SHA1_DES3, + .name = "des3-hmac-sha1", + .encrypt_name = "cbc(des3_ede)", + .cksum_name = "hmac(sha1)", + .encrypt = krb5_encrypt, + .decrypt = krb5_decrypt, + .mk_key = gss_krb5_des3_make_key, + .signalg = SGN_ALG_HMAC_SHA1_DES3_KD, + .sealalg = SEAL_ALG_DES3KD, + .keybytes = 21, + .keylength = 24, + .blocksize = 8, + .conflen = 8, + .cksumlength = 20, + .keyed_cksum = 1, + }, + /* + * AES128 + */ + { + .etype = ENCTYPE_AES128_CTS_HMAC_SHA1_96, + .ctype = CKSUMTYPE_HMAC_SHA1_96_AES128, + .name = "aes128-cts", + .encrypt_name = "cts(cbc(aes))", + .cksum_name = "hmac(sha1)", + .encrypt = krb5_encrypt, + .decrypt = krb5_decrypt, + .mk_key = gss_krb5_aes_make_key, + .encrypt_v2 = gss_krb5_aes_encrypt, + .decrypt_v2 = gss_krb5_aes_decrypt, + .signalg = -1, + .sealalg = -1, + .keybytes = 16, + .keylength = 16, + .blocksize = 16, + .conflen = 16, + .cksumlength = 12, + .keyed_cksum = 1, + }, + /* + * AES256 + */ + { + .etype = ENCTYPE_AES256_CTS_HMAC_SHA1_96, + .ctype = CKSUMTYPE_HMAC_SHA1_96_AES256, + .name = "aes256-cts", + .encrypt_name = "cts(cbc(aes))", + .cksum_name = "hmac(sha1)", + .encrypt = krb5_encrypt, + .decrypt = krb5_decrypt, + .mk_key = gss_krb5_aes_make_key, + .encrypt_v2 = gss_krb5_aes_encrypt, + .decrypt_v2 = gss_krb5_aes_decrypt, + .signalg = -1, + .sealalg = -1, + .keybytes = 32, + .keylength = 32, + .blocksize = 16, + .conflen = 16, + .cksumlength = 12, + .keyed_cksum = 1, + }, +}; + +static const int num_supported_enctypes = + ARRAY_SIZE(supported_gss_krb5_enctypes); + +static int +supported_gss_krb5_enctype(int etype) +{ + int i; + for (i = 0; i < num_supported_enctypes; i++) + if (supported_gss_krb5_enctypes[i].etype == etype) + return 1; + return 0; +} + +static const struct gss_krb5_enctype * +get_gss_krb5_enctype(int etype) +{ + int i; + for (i = 0; i < num_supported_enctypes; i++) + if (supported_gss_krb5_enctypes[i].etype == etype) + return &supported_gss_krb5_enctypes[i]; + return NULL; +} + +static inline const void * +get_key(const void *p, const void *end, + struct krb5_ctx *ctx, struct crypto_sync_skcipher **res) +{ + struct xdr_netobj key; + int alg; + + p = simple_get_bytes(p, end, &alg, sizeof(alg)); + if (IS_ERR(p)) + goto out_err; + + switch (alg) { + case ENCTYPE_DES_CBC_CRC: + case ENCTYPE_DES_CBC_MD4: + case ENCTYPE_DES_CBC_MD5: + /* Map all these key types to ENCTYPE_DES_CBC_RAW */ + alg = ENCTYPE_DES_CBC_RAW; + break; + } + + if (!supported_gss_krb5_enctype(alg)) { + printk(KERN_WARNING "gss_kerberos_mech: unsupported " + "encryption key algorithm %d\n", alg); + p = ERR_PTR(-EINVAL); + goto out_err; + } + p = simple_get_netobj(p, end, &key); + if (IS_ERR(p)) + goto out_err; + + *res = crypto_alloc_sync_skcipher(ctx->gk5e->encrypt_name, 0, 0); + if (IS_ERR(*res)) { + printk(KERN_WARNING "gss_kerberos_mech: unable to initialize " + "crypto algorithm %s\n", ctx->gk5e->encrypt_name); + *res = NULL; + goto out_err_free_key; + } + if (crypto_sync_skcipher_setkey(*res, key.data, key.len)) { + printk(KERN_WARNING "gss_kerberos_mech: error setting key for " + "crypto algorithm %s\n", ctx->gk5e->encrypt_name); + goto out_err_free_tfm; + } + + kfree(key.data); + return p; + +out_err_free_tfm: + crypto_free_sync_skcipher(*res); +out_err_free_key: + kfree(key.data); + p = ERR_PTR(-EINVAL); +out_err: + return p; +} + +static int +gss_import_v1_context(const void *p, const void *end, struct krb5_ctx *ctx) +{ + u32 seq_send; + int tmp; + u32 time32; + + p = simple_get_bytes(p, end, &ctx->initiate, sizeof(ctx->initiate)); + if (IS_ERR(p)) + goto out_err; + + /* Old format supports only DES! Any other enctype uses new format */ + ctx->enctype = ENCTYPE_DES_CBC_RAW; + + ctx->gk5e = get_gss_krb5_enctype(ctx->enctype); + if (ctx->gk5e == NULL) { + p = ERR_PTR(-EINVAL); + goto out_err; + } + + /* The downcall format was designed before we completely understood + * the uses of the context fields; so it includes some stuff we + * just give some minimal sanity-checking, and some we ignore + * completely (like the next twenty bytes): */ + if (unlikely(p + 20 > end || p + 20 < p)) { + p = ERR_PTR(-EFAULT); + goto out_err; + } + p += 20; + p = simple_get_bytes(p, end, &tmp, sizeof(tmp)); + if (IS_ERR(p)) + goto out_err; + if (tmp != SGN_ALG_DES_MAC_MD5) { + p = ERR_PTR(-ENOSYS); + goto out_err; + } + p = simple_get_bytes(p, end, &tmp, sizeof(tmp)); + if (IS_ERR(p)) + goto out_err; + if (tmp != SEAL_ALG_DES) { + p = ERR_PTR(-ENOSYS); + goto out_err; + } + p = simple_get_bytes(p, end, &time32, sizeof(time32)); + if (IS_ERR(p)) + goto out_err; + /* unsigned 32-bit time overflows in year 2106 */ + ctx->endtime = (time64_t)time32; + p = simple_get_bytes(p, end, &seq_send, sizeof(seq_send)); + if (IS_ERR(p)) + goto out_err; + atomic_set(&ctx->seq_send, seq_send); + p = simple_get_netobj(p, end, &ctx->mech_used); + if (IS_ERR(p)) + goto out_err; + p = get_key(p, end, ctx, &ctx->enc); + if (IS_ERR(p)) + goto out_err_free_mech; + p = get_key(p, end, ctx, &ctx->seq); + if (IS_ERR(p)) + goto out_err_free_key1; + if (p != end) { + p = ERR_PTR(-EFAULT); + goto out_err_free_key2; + } + + return 0; + +out_err_free_key2: + crypto_free_sync_skcipher(ctx->seq); +out_err_free_key1: + crypto_free_sync_skcipher(ctx->enc); +out_err_free_mech: + kfree(ctx->mech_used.data); +out_err: + return PTR_ERR(p); +} + +static struct crypto_sync_skcipher * +context_v2_alloc_cipher(struct krb5_ctx *ctx, const char *cname, u8 *key) +{ + struct crypto_sync_skcipher *cp; + + cp = crypto_alloc_sync_skcipher(cname, 0, 0); + if (IS_ERR(cp)) { + dprintk("gss_kerberos_mech: unable to initialize " + "crypto algorithm %s\n", cname); + return NULL; + } + if (crypto_sync_skcipher_setkey(cp, key, ctx->gk5e->keylength)) { + dprintk("gss_kerberos_mech: error setting key for " + "crypto algorithm %s\n", cname); + crypto_free_sync_skcipher(cp); + return NULL; + } + return cp; +} + +static inline void +set_cdata(u8 cdata[GSS_KRB5_K5CLENGTH], u32 usage, u8 seed) +{ + cdata[0] = (usage>>24)&0xff; + cdata[1] = (usage>>16)&0xff; + cdata[2] = (usage>>8)&0xff; + cdata[3] = usage&0xff; + cdata[4] = seed; +} + +static int +context_derive_keys_des3(struct krb5_ctx *ctx, gfp_t gfp_mask) +{ + struct xdr_netobj c, keyin, keyout; + u8 cdata[GSS_KRB5_K5CLENGTH]; + u32 err; + + c.len = GSS_KRB5_K5CLENGTH; + c.data = cdata; + + keyin.data = ctx->Ksess; + keyin.len = ctx->gk5e->keylength; + keyout.len = ctx->gk5e->keylength; + + /* seq uses the raw key */ + ctx->seq = context_v2_alloc_cipher(ctx, ctx->gk5e->encrypt_name, + ctx->Ksess); + if (ctx->seq == NULL) + goto out_err; + + ctx->enc = context_v2_alloc_cipher(ctx, ctx->gk5e->encrypt_name, + ctx->Ksess); + if (ctx->enc == NULL) + goto out_free_seq; + + /* derive cksum */ + set_cdata(cdata, KG_USAGE_SIGN, KEY_USAGE_SEED_CHECKSUM); + keyout.data = ctx->cksum; + err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask); + if (err) { + dprintk("%s: Error %d deriving cksum key\n", + __func__, err); + goto out_free_enc; + } + + return 0; + +out_free_enc: + crypto_free_sync_skcipher(ctx->enc); +out_free_seq: + crypto_free_sync_skcipher(ctx->seq); +out_err: + return -EINVAL; +} + +static int +context_derive_keys_new(struct krb5_ctx *ctx, gfp_t gfp_mask) +{ + struct xdr_netobj c, keyin, keyout; + u8 cdata[GSS_KRB5_K5CLENGTH]; + u32 err; + + c.len = GSS_KRB5_K5CLENGTH; + c.data = cdata; + + keyin.data = ctx->Ksess; + keyin.len = ctx->gk5e->keylength; + keyout.len = ctx->gk5e->keylength; + + /* initiator seal encryption */ + set_cdata(cdata, KG_USAGE_INITIATOR_SEAL, KEY_USAGE_SEED_ENCRYPTION); + keyout.data = ctx->initiator_seal; + err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask); + if (err) { + dprintk("%s: Error %d deriving initiator_seal key\n", + __func__, err); + goto out_err; + } + ctx->initiator_enc = context_v2_alloc_cipher(ctx, + ctx->gk5e->encrypt_name, + ctx->initiator_seal); + if (ctx->initiator_enc == NULL) + goto out_err; + + /* acceptor seal encryption */ + set_cdata(cdata, KG_USAGE_ACCEPTOR_SEAL, KEY_USAGE_SEED_ENCRYPTION); + keyout.data = ctx->acceptor_seal; + err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask); + if (err) { + dprintk("%s: Error %d deriving acceptor_seal key\n", + __func__, err); + goto out_free_initiator_enc; + } + ctx->acceptor_enc = context_v2_alloc_cipher(ctx, + ctx->gk5e->encrypt_name, + ctx->acceptor_seal); + if (ctx->acceptor_enc == NULL) + goto out_free_initiator_enc; + + /* initiator sign checksum */ + set_cdata(cdata, KG_USAGE_INITIATOR_SIGN, KEY_USAGE_SEED_CHECKSUM); + keyout.data = ctx->initiator_sign; + err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask); + if (err) { + dprintk("%s: Error %d deriving initiator_sign key\n", + __func__, err); + goto out_free_acceptor_enc; + } + + /* acceptor sign checksum */ + set_cdata(cdata, KG_USAGE_ACCEPTOR_SIGN, KEY_USAGE_SEED_CHECKSUM); + keyout.data = ctx->acceptor_sign; + err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask); + if (err) { + dprintk("%s: Error %d deriving acceptor_sign key\n", + __func__, err); + goto out_free_acceptor_enc; + } + + /* initiator seal integrity */ + set_cdata(cdata, KG_USAGE_INITIATOR_SEAL, KEY_USAGE_SEED_INTEGRITY); + keyout.data = ctx->initiator_integ; + err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask); + if (err) { + dprintk("%s: Error %d deriving initiator_integ key\n", + __func__, err); + goto out_free_acceptor_enc; + } + + /* acceptor seal integrity */ + set_cdata(cdata, KG_USAGE_ACCEPTOR_SEAL, KEY_USAGE_SEED_INTEGRITY); + keyout.data = ctx->acceptor_integ; + err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask); + if (err) { + dprintk("%s: Error %d deriving acceptor_integ key\n", + __func__, err); + goto out_free_acceptor_enc; + } + + switch (ctx->enctype) { + case ENCTYPE_AES128_CTS_HMAC_SHA1_96: + case ENCTYPE_AES256_CTS_HMAC_SHA1_96: + ctx->initiator_enc_aux = + context_v2_alloc_cipher(ctx, "cbc(aes)", + ctx->initiator_seal); + if (ctx->initiator_enc_aux == NULL) + goto out_free_acceptor_enc; + ctx->acceptor_enc_aux = + context_v2_alloc_cipher(ctx, "cbc(aes)", + ctx->acceptor_seal); + if (ctx->acceptor_enc_aux == NULL) { + crypto_free_sync_skcipher(ctx->initiator_enc_aux); + goto out_free_acceptor_enc; + } + } + + return 0; + +out_free_acceptor_enc: + crypto_free_sync_skcipher(ctx->acceptor_enc); +out_free_initiator_enc: + crypto_free_sync_skcipher(ctx->initiator_enc); +out_err: + return -EINVAL; +} + +static int +gss_import_v2_context(const void *p, const void *end, struct krb5_ctx *ctx, + gfp_t gfp_mask) +{ + u64 seq_send64; + int keylen; + u32 time32; + + p = simple_get_bytes(p, end, &ctx->flags, sizeof(ctx->flags)); + if (IS_ERR(p)) + goto out_err; + ctx->initiate = ctx->flags & KRB5_CTX_FLAG_INITIATOR; + + p = simple_get_bytes(p, end, &time32, sizeof(time32)); + if (IS_ERR(p)) + goto out_err; + /* unsigned 32-bit time overflows in year 2106 */ + ctx->endtime = (time64_t)time32; + p = simple_get_bytes(p, end, &seq_send64, sizeof(seq_send64)); + if (IS_ERR(p)) + goto out_err; + atomic64_set(&ctx->seq_send64, seq_send64); + /* set seq_send for use by "older" enctypes */ + atomic_set(&ctx->seq_send, seq_send64); + if (seq_send64 != atomic_read(&ctx->seq_send)) { + dprintk("%s: seq_send64 %llx, seq_send %x overflow?\n", __func__, + seq_send64, atomic_read(&ctx->seq_send)); + p = ERR_PTR(-EINVAL); + goto out_err; + } + p = simple_get_bytes(p, end, &ctx->enctype, sizeof(ctx->enctype)); + if (IS_ERR(p)) + goto out_err; + /* Map ENCTYPE_DES3_CBC_SHA1 to ENCTYPE_DES3_CBC_RAW */ + if (ctx->enctype == ENCTYPE_DES3_CBC_SHA1) + ctx->enctype = ENCTYPE_DES3_CBC_RAW; + ctx->gk5e = get_gss_krb5_enctype(ctx->enctype); + if (ctx->gk5e == NULL) { + dprintk("gss_kerberos_mech: unsupported krb5 enctype %u\n", + ctx->enctype); + p = ERR_PTR(-EINVAL); + goto out_err; + } + keylen = ctx->gk5e->keylength; + + p = simple_get_bytes(p, end, ctx->Ksess, keylen); + if (IS_ERR(p)) + goto out_err; + + if (p != end) { + p = ERR_PTR(-EINVAL); + goto out_err; + } + + ctx->mech_used.data = kmemdup(gss_kerberos_mech.gm_oid.data, + gss_kerberos_mech.gm_oid.len, gfp_mask); + if (unlikely(ctx->mech_used.data == NULL)) { + p = ERR_PTR(-ENOMEM); + goto out_err; + } + ctx->mech_used.len = gss_kerberos_mech.gm_oid.len; + + switch (ctx->enctype) { + case ENCTYPE_DES3_CBC_RAW: + return context_derive_keys_des3(ctx, gfp_mask); + case ENCTYPE_AES128_CTS_HMAC_SHA1_96: + case ENCTYPE_AES256_CTS_HMAC_SHA1_96: + return context_derive_keys_new(ctx, gfp_mask); + default: + return -EINVAL; + } + +out_err: + return PTR_ERR(p); +} + +static int +gss_import_sec_context_kerberos(const void *p, size_t len, + struct gss_ctx *ctx_id, + time64_t *endtime, + gfp_t gfp_mask) +{ + const void *end = (const void *)((const char *)p + len); + struct krb5_ctx *ctx; + int ret; + + ctx = kzalloc(sizeof(*ctx), gfp_mask); + if (ctx == NULL) + return -ENOMEM; + + if (len == 85) + ret = gss_import_v1_context(p, end, ctx); + else + ret = gss_import_v2_context(p, end, ctx, gfp_mask); + + if (ret == 0) { + ctx_id->internal_ctx_id = ctx; + if (endtime) + *endtime = ctx->endtime; + } else + kfree(ctx); + + dprintk("RPC: %s: returning %d\n", __func__, ret); + return ret; +} + +static void +gss_delete_sec_context_kerberos(void *internal_ctx) { + struct krb5_ctx *kctx = internal_ctx; + + crypto_free_sync_skcipher(kctx->seq); + crypto_free_sync_skcipher(kctx->enc); + crypto_free_sync_skcipher(kctx->acceptor_enc); + crypto_free_sync_skcipher(kctx->initiator_enc); + crypto_free_sync_skcipher(kctx->acceptor_enc_aux); + crypto_free_sync_skcipher(kctx->initiator_enc_aux); + kfree(kctx->mech_used.data); + kfree(kctx); +} + +static const struct gss_api_ops gss_kerberos_ops = { + .gss_import_sec_context = gss_import_sec_context_kerberos, + .gss_get_mic = gss_get_mic_kerberos, + .gss_verify_mic = gss_verify_mic_kerberos, + .gss_wrap = gss_wrap_kerberos, + .gss_unwrap = gss_unwrap_kerberos, + .gss_delete_sec_context = gss_delete_sec_context_kerberos, +}; + +static struct pf_desc gss_kerberos_pfs[] = { + [0] = { + .pseudoflavor = RPC_AUTH_GSS_KRB5, + .qop = GSS_C_QOP_DEFAULT, + .service = RPC_GSS_SVC_NONE, + .name = "krb5", + }, + [1] = { + .pseudoflavor = RPC_AUTH_GSS_KRB5I, + .qop = GSS_C_QOP_DEFAULT, + .service = RPC_GSS_SVC_INTEGRITY, + .name = "krb5i", + .datatouch = true, + }, + [2] = { + .pseudoflavor = RPC_AUTH_GSS_KRB5P, + .qop = GSS_C_QOP_DEFAULT, + .service = RPC_GSS_SVC_PRIVACY, + .name = "krb5p", + .datatouch = true, + }, +}; + +MODULE_ALIAS("rpc-auth-gss-krb5"); +MODULE_ALIAS("rpc-auth-gss-krb5i"); +MODULE_ALIAS("rpc-auth-gss-krb5p"); +MODULE_ALIAS("rpc-auth-gss-390003"); +MODULE_ALIAS("rpc-auth-gss-390004"); +MODULE_ALIAS("rpc-auth-gss-390005"); +MODULE_ALIAS("rpc-auth-gss-1.2.840.113554.1.2.2"); + +static struct gss_api_mech gss_kerberos_mech = { + .gm_name = "krb5", + .gm_owner = THIS_MODULE, + .gm_oid = { 9, "\x2a\x86\x48\x86\xf7\x12\x01\x02\x02" }, + .gm_ops = &gss_kerberos_ops, + .gm_pf_num = ARRAY_SIZE(gss_kerberos_pfs), + .gm_pfs = gss_kerberos_pfs, + .gm_upcall_enctypes = KRB5_SUPPORTED_ENCTYPES, +}; + +static int __init init_kerberos_module(void) +{ + int status; + + status = gss_mech_register(&gss_kerberos_mech); + if (status) + printk("Failed to register kerberos gss mechanism!\n"); + return status; +} + +static void __exit cleanup_kerberos_module(void) +{ + gss_mech_unregister(&gss_kerberos_mech); +} + +MODULE_LICENSE("GPL"); +module_init(init_kerberos_module); +module_exit(cleanup_kerberos_module); 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