From 8b3a09f3454240cb2c2ab3da02b86f354aab0bd6 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Sun, 15 Jan 2023 12:22:24 -0500 Subject: SUNRPC: Parametrize the key length passed to context_v2_alloc_cipher() Although the Kerberos specs have always listed separate subkey lengths, the Linux kernel's SunRPC GSS Kerberos enctype profiles assume the base key and the derived keys have identical lengths. The aes256-cts-hmac-sha384-192 enctype specifies the length of its checksum and integrity subkeys as 192 bits, but the length of its encryption subkey (Ke) as 256 bits. To support that enctype, parametrize context_v2_alloc_cipher() so that each of its call sites can pass in its desired key length. For now it will be the same length as before (gk5e->keylength), but a subsequent patch will change this. Tested-by: Scott Mayhew Reviewed-by: Simo Sorce Signed-off-by: Chuck Lever --- net/sunrpc/auth_gss/gss_krb5_mech.c | 61 ++++++++++++++++--------------------- 1 file changed, 26 insertions(+), 35 deletions(-) (limited to 'net/sunrpc/auth_gss') diff --git a/net/sunrpc/auth_gss/gss_krb5_mech.c b/net/sunrpc/auth_gss/gss_krb5_mech.c index 9575fb291d33..45f461f9b5ba 100644 --- a/net/sunrpc/auth_gss/gss_krb5_mech.c +++ b/net/sunrpc/auth_gss/gss_krb5_mech.c @@ -341,26 +341,6 @@ out_err: return PTR_ERR(p); } -static inline 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; -} - #if defined(CONFIG_RPCSEC_GSS_KRB5_SIMPLIFIED) static int gss_krb5_import_ctx_des(struct krb5_ctx *ctx, gfp_t gfp_mask) @@ -403,6 +383,21 @@ out_err: #if defined(CONFIG_RPCSEC_GSS_KRB5_CRYPTOSYSTEM) +static struct crypto_sync_skcipher * +gss_krb5_alloc_cipher_v2(const char *cname, const struct xdr_netobj *key) +{ + struct crypto_sync_skcipher *tfm; + + tfm = crypto_alloc_sync_skcipher(cname, 0, 0); + if (IS_ERR(tfm)) + return NULL; + if (crypto_sync_skcipher_setkey(tfm, key->data, key->len)) { + crypto_free_sync_skcipher(tfm); + return NULL; + } + return tfm; +} + static struct crypto_ahash * gss_krb5_alloc_hash_v2(struct krb5_ctx *kctx, const struct xdr_netobj *key) { @@ -427,27 +422,24 @@ gss_krb5_import_ctx_v2(struct krb5_ctx *ctx, gfp_t gfp_mask) }; struct xdr_netobj keyout; int ret = -EINVAL; - void *subkey; - subkey = kmalloc(ctx->gk5e->keylength, gfp_mask); - if (!subkey) + keyout.data = kmalloc(ctx->gk5e->keylength, gfp_mask); + if (!keyout.data) return -ENOMEM; keyout.len = ctx->gk5e->keylength; - keyout.data = subkey; /* initiator seal encryption */ if (krb5_derive_key(ctx, &keyin, &keyout, KG_USAGE_INITIATOR_SEAL, KEY_USAGE_SEED_ENCRYPTION, gfp_mask)) goto out; - ctx->initiator_enc = context_v2_alloc_cipher(ctx, - ctx->gk5e->encrypt_name, - subkey); + ctx->initiator_enc = gss_krb5_alloc_cipher_v2(ctx->gk5e->encrypt_name, + &keyout); if (ctx->initiator_enc == NULL) goto out; if (ctx->gk5e->aux_cipher) { ctx->initiator_enc_aux = - context_v2_alloc_cipher(ctx, ctx->gk5e->aux_cipher, - subkey); + gss_krb5_alloc_cipher_v2(ctx->gk5e->aux_cipher, + &keyout); if (ctx->initiator_enc_aux == NULL) goto out_free; } @@ -456,15 +448,14 @@ gss_krb5_import_ctx_v2(struct krb5_ctx *ctx, gfp_t gfp_mask) if (krb5_derive_key(ctx, &keyin, &keyout, KG_USAGE_ACCEPTOR_SEAL, KEY_USAGE_SEED_ENCRYPTION, gfp_mask)) goto out_free; - ctx->acceptor_enc = context_v2_alloc_cipher(ctx, - ctx->gk5e->encrypt_name, - subkey); + ctx->acceptor_enc = gss_krb5_alloc_cipher_v2(ctx->gk5e->encrypt_name, + &keyout); if (ctx->acceptor_enc == NULL) goto out_free; if (ctx->gk5e->aux_cipher) { ctx->acceptor_enc_aux = - context_v2_alloc_cipher(ctx, ctx->gk5e->aux_cipher, - subkey); + gss_krb5_alloc_cipher_v2(ctx->gk5e->aux_cipher, + &keyout); if (ctx->acceptor_enc_aux == NULL) goto out_free; } @@ -503,7 +494,7 @@ gss_krb5_import_ctx_v2(struct krb5_ctx *ctx, gfp_t gfp_mask) ret = 0; out: - kfree_sensitive(subkey); + kfree_sensitive(keyout.data); return ret; out_free: -- cgit v1.2.3