From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- net/sunrpc/auth_gss/gss_krb5_keys.c | 546 ++++++++++++++++++++++++++++++++++++ 1 file changed, 546 insertions(+) create mode 100644 net/sunrpc/auth_gss/gss_krb5_keys.c (limited to 'net/sunrpc/auth_gss/gss_krb5_keys.c') diff --git a/net/sunrpc/auth_gss/gss_krb5_keys.c b/net/sunrpc/auth_gss/gss_krb5_keys.c new file mode 100644 index 0000000000..06d8ee0db0 --- /dev/null +++ b/net/sunrpc/auth_gss/gss_krb5_keys.c @@ -0,0 +1,546 @@ +/* + * COPYRIGHT (c) 2008 + * The Regents of the University of Michigan + * ALL RIGHTS RESERVED + * + * Permission is granted to use, copy, create derivative works + * and redistribute this software and such derivative works + * for any purpose, so long as the name of The University of + * Michigan is not used in any advertising or publicity + * pertaining to the use of distribution of this software + * without specific, written prior authorization. If the + * above copyright notice or any other identification of the + * University of Michigan is included in any copy of any + * portion of this software, then the disclaimer below must + * also be included. + * + * THIS SOFTWARE IS PROVIDED AS IS, WITHOUT REPRESENTATION + * FROM THE UNIVERSITY OF MICHIGAN AS TO ITS FITNESS FOR ANY + * PURPOSE, AND WITHOUT WARRANTY BY THE UNIVERSITY OF + * MICHIGAN OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING + * WITHOUT LIMITATION THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE + * REGENTS OF THE UNIVERSITY OF MICHIGAN SHALL NOT BE LIABLE + * FOR ANY DAMAGES, INCLUDING SPECIAL, INDIRECT, INCIDENTAL, OR + * CONSEQUENTIAL DAMAGES, WITH RESPECT TO ANY CLAIM ARISING + * OUT OF OR IN CONNECTION WITH THE USE OF THE SOFTWARE, EVEN + * IF IT HAS BEEN OR IS HEREAFTER ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGES. + */ + +/* + * Copyright (C) 1998 by the FundsXpress, INC. + * + * All rights reserved. + * + * Export of this software from the United States of America may require + * a specific license from the United States Government. It is the + * responsibility of any person or organization contemplating export to + * obtain such a license before exporting. + * + * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and + * distribute this software and its documentation for any purpose and + * without fee is hereby granted, provided that the above copyright + * notice appear in all copies and that both that copyright notice and + * this permission notice appear in supporting documentation, and that + * the name of FundsXpress. not be used in advertising or publicity pertaining + * to distribution of the software without specific, written prior + * permission. FundsXpress makes no representations about the suitability of + * this software for any purpose. It is provided "as is" without express + * or implied warranty. + * + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED + * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include "gss_krb5_internal.h" + +#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) +# define RPCDBG_FACILITY RPCDBG_AUTH +#endif + +/** + * krb5_nfold - n-fold function + * @inbits: number of bits in @in + * @in: buffer containing input to fold + * @outbits: number of bits in the output buffer + * @out: buffer to hold the result + * + * This is the n-fold function as described in rfc3961, sec 5.1 + * Taken from MIT Kerberos and modified. + */ +VISIBLE_IF_KUNIT +void krb5_nfold(u32 inbits, const u8 *in, u32 outbits, u8 *out) +{ + unsigned long ulcm; + int byte, i, msbit; + + /* the code below is more readable if I make these bytes + instead of bits */ + + inbits >>= 3; + outbits >>= 3; + + /* first compute lcm(n,k) */ + ulcm = lcm(inbits, outbits); + + /* now do the real work */ + + memset(out, 0, outbits); + byte = 0; + + /* this will end up cycling through k lcm(k,n)/k times, which + is correct */ + for (i = ulcm-1; i >= 0; i--) { + /* compute the msbit in k which gets added into this byte */ + msbit = ( + /* first, start with the msbit in the first, + * unrotated byte */ + ((inbits << 3) - 1) + /* then, for each byte, shift to the right + * for each repetition */ + + (((inbits << 3) + 13) * (i/inbits)) + /* last, pick out the correct byte within + * that shifted repetition */ + + ((inbits - (i % inbits)) << 3) + ) % (inbits << 3); + + /* pull out the byte value itself */ + byte += (((in[((inbits - 1) - (msbit >> 3)) % inbits] << 8)| + (in[((inbits) - (msbit >> 3)) % inbits])) + >> ((msbit & 7) + 1)) & 0xff; + + /* do the addition */ + byte += out[i % outbits]; + out[i % outbits] = byte & 0xff; + + /* keep around the carry bit, if any */ + byte >>= 8; + + } + + /* if there's a carry bit left over, add it back in */ + if (byte) { + for (i = outbits - 1; i >= 0; i--) { + /* do the addition */ + byte += out[i]; + out[i] = byte & 0xff; + + /* keep around the carry bit, if any */ + byte >>= 8; + } + } +} +EXPORT_SYMBOL_IF_KUNIT(krb5_nfold); + +/* + * This is the DK (derive_key) function as described in rfc3961, sec 5.1 + * Taken from MIT Kerberos and modified. + */ +static int krb5_DK(const struct gss_krb5_enctype *gk5e, + const struct xdr_netobj *inkey, u8 *rawkey, + const struct xdr_netobj *in_constant, gfp_t gfp_mask) +{ + size_t blocksize, keybytes, keylength, n; + unsigned char *inblockdata, *outblockdata; + struct xdr_netobj inblock, outblock; + struct crypto_sync_skcipher *cipher; + int ret = -EINVAL; + + keybytes = gk5e->keybytes; + keylength = gk5e->keylength; + + if (inkey->len != keylength) + goto err_return; + + cipher = crypto_alloc_sync_skcipher(gk5e->encrypt_name, 0, 0); + if (IS_ERR(cipher)) + goto err_return; + blocksize = crypto_sync_skcipher_blocksize(cipher); + if (crypto_sync_skcipher_setkey(cipher, inkey->data, inkey->len)) + goto err_return; + + ret = -ENOMEM; + inblockdata = kmalloc(blocksize, gfp_mask); + if (inblockdata == NULL) + goto err_free_cipher; + + outblockdata = kmalloc(blocksize, gfp_mask); + if (outblockdata == NULL) + goto err_free_in; + + inblock.data = (char *) inblockdata; + inblock.len = blocksize; + + outblock.data = (char *) outblockdata; + outblock.len = blocksize; + + /* initialize the input block */ + + if (in_constant->len == inblock.len) { + memcpy(inblock.data, in_constant->data, inblock.len); + } else { + krb5_nfold(in_constant->len * 8, in_constant->data, + inblock.len * 8, inblock.data); + } + + /* loop encrypting the blocks until enough key bytes are generated */ + + n = 0; + while (n < keybytes) { + krb5_encrypt(cipher, NULL, inblock.data, outblock.data, + inblock.len); + + if ((keybytes - n) <= outblock.len) { + memcpy(rawkey + n, outblock.data, (keybytes - n)); + break; + } + + memcpy(rawkey + n, outblock.data, outblock.len); + memcpy(inblock.data, outblock.data, outblock.len); + n += outblock.len; + } + + ret = 0; + + kfree_sensitive(outblockdata); +err_free_in: + kfree_sensitive(inblockdata); +err_free_cipher: + crypto_free_sync_skcipher(cipher); +err_return: + return ret; +} + +/* + * This is the identity function, with some sanity checking. + */ +static int krb5_random_to_key_v2(const struct gss_krb5_enctype *gk5e, + struct xdr_netobj *randombits, + struct xdr_netobj *key) +{ + int ret = -EINVAL; + + if (key->len != 16 && key->len != 32) { + dprintk("%s: key->len is %d\n", __func__, key->len); + goto err_out; + } + if (randombits->len != 16 && randombits->len != 32) { + dprintk("%s: randombits->len is %d\n", + __func__, randombits->len); + goto err_out; + } + if (randombits->len != key->len) { + dprintk("%s: randombits->len is %d, key->len is %d\n", + __func__, randombits->len, key->len); + goto err_out; + } + memcpy(key->data, randombits->data, key->len); + ret = 0; +err_out: + return ret; +} + +/** + * krb5_derive_key_v2 - Derive a subkey for an RFC 3962 enctype + * @gk5e: Kerberos 5 enctype profile + * @inkey: base protocol key + * @outkey: OUT: derived key + * @label: subkey usage label + * @gfp_mask: memory allocation control flags + * + * Caller sets @outkey->len to the desired length of the derived key. + * + * On success, returns 0 and fills in @outkey. A negative errno value + * is returned on failure. + */ +int krb5_derive_key_v2(const struct gss_krb5_enctype *gk5e, + const struct xdr_netobj *inkey, + struct xdr_netobj *outkey, + const struct xdr_netobj *label, + gfp_t gfp_mask) +{ + struct xdr_netobj inblock; + int ret; + + inblock.len = gk5e->keybytes; + inblock.data = kmalloc(inblock.len, gfp_mask); + if (!inblock.data) + return -ENOMEM; + + ret = krb5_DK(gk5e, inkey, inblock.data, label, gfp_mask); + if (!ret) + ret = krb5_random_to_key_v2(gk5e, &inblock, outkey); + + kfree_sensitive(inblock.data); + return ret; +} + +/* + * K(i) = CMAC(key, K(i-1) | i | constant | 0x00 | k) + * + * i: A block counter is used with a length of 4 bytes, represented + * in big-endian order. + * + * constant: The label input to the KDF is the usage constant supplied + * to the key derivation function + * + * k: The length of the output key in bits, represented as a 4-byte + * string in big-endian order. + * + * Caller fills in K(i-1) in @step, and receives the result K(i) + * in the same buffer. + */ +static int +krb5_cmac_Ki(struct crypto_shash *tfm, const struct xdr_netobj *constant, + u32 outlen, u32 count, struct xdr_netobj *step) +{ + __be32 k = cpu_to_be32(outlen * 8); + SHASH_DESC_ON_STACK(desc, tfm); + __be32 i = cpu_to_be32(count); + u8 zero = 0; + int ret; + + desc->tfm = tfm; + ret = crypto_shash_init(desc); + if (ret) + goto out_err; + + ret = crypto_shash_update(desc, step->data, step->len); + if (ret) + goto out_err; + ret = crypto_shash_update(desc, (u8 *)&i, sizeof(i)); + if (ret) + goto out_err; + ret = crypto_shash_update(desc, constant->data, constant->len); + if (ret) + goto out_err; + ret = crypto_shash_update(desc, &zero, sizeof(zero)); + if (ret) + goto out_err; + ret = crypto_shash_update(desc, (u8 *)&k, sizeof(k)); + if (ret) + goto out_err; + ret = crypto_shash_final(desc, step->data); + if (ret) + goto out_err; + +out_err: + shash_desc_zero(desc); + return ret; +} + +/** + * krb5_kdf_feedback_cmac - Derive a subkey for a Camellia/CMAC-based enctype + * @gk5e: Kerberos 5 enctype parameters + * @inkey: base protocol key + * @outkey: OUT: derived key + * @constant: subkey usage label + * @gfp_mask: memory allocation control flags + * + * RFC 6803 Section 3: + * + * "We use a key derivation function from the family specified in + * [SP800-108], Section 5.2, 'KDF in Feedback Mode'." + * + * n = ceiling(k / 128) + * K(0) = zeros + * K(i) = CMAC(key, K(i-1) | i | constant | 0x00 | k) + * DR(key, constant) = k-truncate(K(1) | K(2) | ... | K(n)) + * KDF-FEEDBACK-CMAC(key, constant) = random-to-key(DR(key, constant)) + * + * Caller sets @outkey->len to the desired length of the derived key (k). + * + * On success, returns 0 and fills in @outkey. A negative errno value + * is returned on failure. + */ +int +krb5_kdf_feedback_cmac(const struct gss_krb5_enctype *gk5e, + const struct xdr_netobj *inkey, + struct xdr_netobj *outkey, + const struct xdr_netobj *constant, + gfp_t gfp_mask) +{ + struct xdr_netobj step = { .data = NULL }; + struct xdr_netobj DR = { .data = NULL }; + unsigned int blocksize, offset; + struct crypto_shash *tfm; + int n, count, ret; + + /* + * This implementation assumes the CMAC used for an enctype's + * key derivation is the same as the CMAC used for its + * checksumming. This happens to be true for enctypes that + * are currently supported by this implementation. + */ + tfm = crypto_alloc_shash(gk5e->cksum_name, 0, 0); + if (IS_ERR(tfm)) { + ret = PTR_ERR(tfm); + goto out; + } + ret = crypto_shash_setkey(tfm, inkey->data, inkey->len); + if (ret) + goto out_free_tfm; + + blocksize = crypto_shash_digestsize(tfm); + n = (outkey->len + blocksize - 1) / blocksize; + + /* K(0) is all zeroes */ + ret = -ENOMEM; + step.len = blocksize; + step.data = kzalloc(step.len, gfp_mask); + if (!step.data) + goto out_free_tfm; + + DR.len = blocksize * n; + DR.data = kmalloc(DR.len, gfp_mask); + if (!DR.data) + goto out_free_tfm; + + /* XXX: Does not handle partial-block key sizes */ + for (offset = 0, count = 1; count <= n; count++) { + ret = krb5_cmac_Ki(tfm, constant, outkey->len, count, &step); + if (ret) + goto out_free_tfm; + + memcpy(DR.data + offset, step.data, blocksize); + offset += blocksize; + } + + /* k-truncate and random-to-key */ + memcpy(outkey->data, DR.data, outkey->len); + ret = 0; + +out_free_tfm: + crypto_free_shash(tfm); +out: + kfree_sensitive(step.data); + kfree_sensitive(DR.data); + return ret; +} + +/* + * K1 = HMAC-SHA(key, 0x00000001 | label | 0x00 | k) + * + * key: The source of entropy from which subsequent keys are derived. + * + * label: An octet string describing the intended usage of the + * derived key. + * + * k: Length in bits of the key to be outputted, expressed in + * big-endian binary representation in 4 bytes. + */ +static int +krb5_hmac_K1(struct crypto_shash *tfm, const struct xdr_netobj *label, + u32 outlen, struct xdr_netobj *K1) +{ + __be32 k = cpu_to_be32(outlen * 8); + SHASH_DESC_ON_STACK(desc, tfm); + __be32 one = cpu_to_be32(1); + u8 zero = 0; + int ret; + + desc->tfm = tfm; + ret = crypto_shash_init(desc); + if (ret) + goto out_err; + ret = crypto_shash_update(desc, (u8 *)&one, sizeof(one)); + if (ret) + goto out_err; + ret = crypto_shash_update(desc, label->data, label->len); + if (ret) + goto out_err; + ret = crypto_shash_update(desc, &zero, sizeof(zero)); + if (ret) + goto out_err; + ret = crypto_shash_update(desc, (u8 *)&k, sizeof(k)); + if (ret) + goto out_err; + ret = crypto_shash_final(desc, K1->data); + if (ret) + goto out_err; + +out_err: + shash_desc_zero(desc); + return ret; +} + +/** + * krb5_kdf_hmac_sha2 - Derive a subkey for an AES/SHA2-based enctype + * @gk5e: Kerberos 5 enctype policy parameters + * @inkey: base protocol key + * @outkey: OUT: derived key + * @label: subkey usage label + * @gfp_mask: memory allocation control flags + * + * RFC 8009 Section 3: + * + * "We use a key derivation function from Section 5.1 of [SP800-108], + * which uses the HMAC algorithm as the PRF." + * + * function KDF-HMAC-SHA2(key, label, [context,] k): + * k-truncate(K1) + * + * Caller sets @outkey->len to the desired length of the derived key. + * + * On success, returns 0 and fills in @outkey. A negative errno value + * is returned on failure. + */ +int +krb5_kdf_hmac_sha2(const struct gss_krb5_enctype *gk5e, + const struct xdr_netobj *inkey, + struct xdr_netobj *outkey, + const struct xdr_netobj *label, + gfp_t gfp_mask) +{ + struct crypto_shash *tfm; + struct xdr_netobj K1 = { + .data = NULL, + }; + int ret; + + /* + * This implementation assumes the HMAC used for an enctype's + * key derivation is the same as the HMAC used for its + * checksumming. This happens to be true for enctypes that + * are currently supported by this implementation. + */ + tfm = crypto_alloc_shash(gk5e->cksum_name, 0, 0); + if (IS_ERR(tfm)) { + ret = PTR_ERR(tfm); + goto out; + } + ret = crypto_shash_setkey(tfm, inkey->data, inkey->len); + if (ret) + goto out_free_tfm; + + K1.len = crypto_shash_digestsize(tfm); + K1.data = kmalloc(K1.len, gfp_mask); + if (!K1.data) { + ret = -ENOMEM; + goto out_free_tfm; + } + + ret = krb5_hmac_K1(tfm, label, outkey->len, &K1); + if (ret) + goto out_free_tfm; + + /* k-truncate and random-to-key */ + memcpy(outkey->data, K1.data, outkey->len); + +out_free_tfm: + kfree_sensitive(K1.data); + crypto_free_shash(tfm); +out: + return ret; +} -- cgit v1.2.3