1 files changed, 429 insertions, 65 deletions

diff --git a/drivers/nvme/common/auth.c b/drivers/nvme/common/auth.c
index d90e4f0c08b7..e07e7d4bf8b6 100644
--- a/drivers/nvme/common/auth.c
+++ b/drivers/nvme/common/auth.c
@@ -8,12 +8,15 @@
 #include <linux/base64.h>
 #include <linux/prandom.h>
 #include <linux/scatterlist.h>
-#include <asm/unaligned.h>
+#include <linux/unaligned.h>
 #include <crypto/hash.h>
 #include <crypto/dh.h>
+#include <crypto/hkdf.h>
 #include <linux/nvme.h>
 #include <linux/nvme-auth.h>
 
+#define HKDF_MAX_HASHLEN 64
+
 static u32 nvme_dhchap_seqnum;
 static DEFINE_MUTEX(nvme_dhchap_mutex);
 
@@ -150,6 +153,14 @@ size_t nvme_auth_hmac_hash_len(u8 hmac_id)
 }
 EXPORT_SYMBOL_GPL(nvme_auth_hmac_hash_len);
 
+u32 nvme_auth_key_struct_size(u32 key_len)
+{
+	struct nvme_dhchap_key key;
+
+	return struct_size(&key, key, key_len);
+}
+EXPORT_SYMBOL_GPL(nvme_auth_key_struct_size);
+
 struct nvme_dhchap_key *nvme_auth_extract_key(unsigned char *secret,
 					      u8 key_hash)
 {
@@ -163,16 +174,11 @@ struct nvme_dhchap_key *nvme_auth_extract_key(unsigned char *secret,
 	p = strrchr(secret, ':');
 	if (p)
 		allocated_len = p - secret;
-	key = kzalloc(sizeof(*key), GFP_KERNEL);
+	key = nvme_auth_alloc_key(allocated_len, 0);
 	if (!key)
 		return ERR_PTR(-ENOMEM);
-	key->key = kzalloc(allocated_len, GFP_KERNEL);
-	if (!key->key) {
-		ret = -ENOMEM;
-		goto out_free_key;
-	}
 
-	key_len = base64_decode(secret, allocated_len, key->key);
+	key_len = base64_decode(secret, allocated_len, key->key, true, BASE64_STD);
 	if (key_len < 0) {
 		pr_debug("base64 key decoding error %d\n",
 			 key_len);
@@ -187,14 +193,6 @@ struct nvme_dhchap_key *nvme_auth_extract_key(unsigned char *secret,
 		goto out_free_secret;
 	}
 
-	if (key_hash > 0 &&
-	    (key_len - 4) != nvme_auth_hmac_hash_len(key_hash)) {
-		pr_err("Mismatched key len %d for %s\n", key_len,
-		       nvme_auth_hmac_name(key_hash));
-		ret = -EINVAL;
-		goto out_free_secret;
-	}
-
 	/* The last four bytes is the CRC in little-endian format */
 	key_len -= 4;
 	/*
@@ -213,37 +211,51 @@ struct nvme_dhchap_key *nvme_auth_extract_key(unsigned char *secret,
 	key->hash = key_hash;
 	return key;
 out_free_secret:
-	kfree_sensitive(key->key);
-out_free_key:
-	kfree(key);
+	nvme_auth_free_key(key);
 	return ERR_PTR(ret);
 }
 EXPORT_SYMBOL_GPL(nvme_auth_extract_key);
 
+struct nvme_dhchap_key *nvme_auth_alloc_key(u32 len, u8 hash)
+{
+	u32 num_bytes = nvme_auth_key_struct_size(len);
+	struct nvme_dhchap_key *key = kzalloc(num_bytes, GFP_KERNEL);
+
+	if (key) {
+		key->len = len;
+		key->hash = hash;
+	}
+	return key;
+}
+EXPORT_SYMBOL_GPL(nvme_auth_alloc_key);
+
 void nvme_auth_free_key(struct nvme_dhchap_key *key)
 {
 	if (!key)
 		return;
-	kfree_sensitive(key->key);
-	kfree(key);
+	kfree_sensitive(key);
 }
 EXPORT_SYMBOL_GPL(nvme_auth_free_key);
 
-u8 *nvme_auth_transform_key(struct nvme_dhchap_key *key, char *nqn)
+struct nvme_dhchap_key *nvme_auth_transform_key(
+		struct nvme_dhchap_key *key, char *nqn)
 {
 	const char *hmac_name;
 	struct crypto_shash *key_tfm;
-	struct shash_desc *shash;
-	u8 *transformed_key;
-	int ret;
+	SHASH_DESC_ON_STACK(shash, key_tfm);
+	struct nvme_dhchap_key *transformed_key;
+	int ret, key_len;
 
-	if (!key || !key->key) {
+	if (!key) {
 		pr_warn("No key specified\n");
 		return ERR_PTR(-ENOKEY);
 	}
 	if (key->hash == 0) {
-		transformed_key = kmemdup(key->key, key->len, GFP_KERNEL);
-		return transformed_key ? transformed_key : ERR_PTR(-ENOMEM);
+		key_len = nvme_auth_key_struct_size(key->len);
+		transformed_key = kmemdup(key, key_len, GFP_KERNEL);
+		if (!transformed_key)
+			return ERR_PTR(-ENOMEM);
+		return transformed_key;
 	}
 	hmac_name = nvme_auth_hmac_name(key->hash);
 	if (!hmac_name) {
@@ -253,20 +265,13 @@ u8 *nvme_auth_transform_key(struct nvme_dhchap_key *key, char *nqn)
 
 	key_tfm = crypto_alloc_shash(hmac_name, 0, 0);
 	if (IS_ERR(key_tfm))
-		return (u8 *)key_tfm;
-
-	shash = kmalloc(sizeof(struct shash_desc) +
-			crypto_shash_descsize(key_tfm),
-			GFP_KERNEL);
-	if (!shash) {
-		ret = -ENOMEM;
-		goto out_free_key;
-	}
+		return ERR_CAST(key_tfm);
 
-	transformed_key = kzalloc(crypto_shash_digestsize(key_tfm), GFP_KERNEL);
+	key_len = crypto_shash_digestsize(key_tfm);
+	transformed_key = nvme_auth_alloc_key(key_len, key->hash);
 	if (!transformed_key) {
 		ret = -ENOMEM;
-		goto out_free_shash;
+		goto out_free_key;
 	}
 
 	shash->tfm = key_tfm;
@@ -282,19 +287,16 @@ u8 *nvme_auth_transform_key(struct nvme_dhchap_key *key, char *nqn)
 	ret = crypto_shash_update(shash, "NVMe-over-Fabrics", 17);
 	if (ret < 0)
 		goto out_free_transformed_key;
-	ret = crypto_shash_final(shash, transformed_key);
+	ret = crypto_shash_final(shash, transformed_key->key);
 	if (ret < 0)
 		goto out_free_transformed_key;
 
-	kfree(shash);
 	crypto_free_shash(key_tfm);
 
 	return transformed_key;
 
 out_free_transformed_key:
-	kfree_sensitive(transformed_key);
-out_free_shash:
-	kfree(shash);
+	nvme_auth_free_key(transformed_key);
 out_free_key:
 	crypto_free_shash(key_tfm);
 
@@ -331,7 +333,6 @@ int nvme_auth_augmented_challenge(u8 hmac_id, u8 *skey, size_t skey_len,
 		u8 *challenge, u8 *aug, size_t hlen)
 {
 	struct crypto_shash *tfm;
-	struct shash_desc *desc;
 	u8 *hashed_key;
 	const char *hmac_name;
 	int ret;
@@ -359,29 +360,11 @@ int nvme_auth_augmented_challenge(u8 hmac_id, u8 *skey, size_t skey_len,
 		goto out_free_key;
 	}
 
-	desc = kmalloc(sizeof(struct shash_desc) + crypto_shash_descsize(tfm),
-		       GFP_KERNEL);
-	if (!desc) {
-		ret = -ENOMEM;
-		goto out_free_hash;
-	}
-	desc->tfm = tfm;
-
 	ret = crypto_shash_setkey(tfm, hashed_key, hlen);
 	if (ret)
-		goto out_free_desc;
-
-	ret = crypto_shash_init(desc);
-	if (ret)
-		goto out_free_desc;
-
-	ret = crypto_shash_update(desc, challenge, hlen);
-	if (ret)
-		goto out_free_desc;
+		goto out_free_hash;
 
-	ret = crypto_shash_final(desc, aug);
-out_free_desc:
-	kfree_sensitive(desc);
+	ret = crypto_shash_tfm_digest(tfm, challenge, hlen, aug);
 out_free_hash:
 	crypto_free_shash(tfm);
 out_free_key:
@@ -480,4 +463,385 @@ int nvme_auth_generate_key(u8 *secret, struct nvme_dhchap_key **ret_key)
 }
 EXPORT_SYMBOL_GPL(nvme_auth_generate_key);
 
+/**
+ * nvme_auth_generate_psk - Generate a PSK for TLS
+ * @hmac_id: Hash function identifier
+ * @skey: Session key
+ * @skey_len: Length of @skey
+ * @c1: Value of challenge C1
+ * @c2: Value of challenge C2
+ * @hash_len: Hash length of the hash algorithm
+ * @ret_psk: Pointer to the resulting generated PSK
+ * @ret_len: length of @ret_psk
+ *
+ * Generate a PSK for TLS as specified in NVMe base specification, section
+ * 8.13.5.9: Generated PSK for TLS
+ *
+ * The generated PSK for TLS shall be computed applying the HMAC function
+ * using the hash function H( ) selected by the HashID parameter in the
+ * DH-HMAC-CHAP_Challenge message with the session key KS as key to the
+ * concatenation of the two challenges C1 and C2 (i.e., generated
+ * PSK = HMAC(KS, C1 || C2)).
+ *
+ * Returns 0 on success with a valid generated PSK pointer in @ret_psk and
+ * the length of @ret_psk in @ret_len, or a negative error number otherwise.
+ */
+int nvme_auth_generate_psk(u8 hmac_id, u8 *skey, size_t skey_len,
+		u8 *c1, u8 *c2, size_t hash_len, u8 **ret_psk, size_t *ret_len)
+{
+	struct crypto_shash *tfm;
+	SHASH_DESC_ON_STACK(shash, tfm);
+	u8 *psk;
+	const char *hmac_name;
+	int ret, psk_len;
+
+	if (!c1 || !c2)
+		return -EINVAL;
+
+	hmac_name = nvme_auth_hmac_name(hmac_id);
+	if (!hmac_name) {
+		pr_warn("%s: invalid hash algorithm %d\n",
+			__func__, hmac_id);
+		return -EINVAL;
+	}
+
+	tfm = crypto_alloc_shash(hmac_name, 0, 0);
+	if (IS_ERR(tfm))
+		return PTR_ERR(tfm);
+
+	psk_len = crypto_shash_digestsize(tfm);
+	psk = kzalloc(psk_len, GFP_KERNEL);
+	if (!psk) {
+		ret = -ENOMEM;
+		goto out_free_tfm;
+	}
+
+	shash->tfm = tfm;
+	ret = crypto_shash_setkey(tfm, skey, skey_len);
+	if (ret)
+		goto out_free_psk;
+
+	ret = crypto_shash_init(shash);
+	if (ret)
+		goto out_free_psk;
+
+	ret = crypto_shash_update(shash, c1, hash_len);
+	if (ret)
+		goto out_free_psk;
+
+	ret = crypto_shash_update(shash, c2, hash_len);
+	if (ret)
+		goto out_free_psk;
+
+	ret = crypto_shash_final(shash, psk);
+	if (!ret) {
+		*ret_psk = psk;
+		*ret_len = psk_len;
+	}
+
+out_free_psk:
+	if (ret)
+		kfree_sensitive(psk);
+out_free_tfm:
+	crypto_free_shash(tfm);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(nvme_auth_generate_psk);
+
+/**
+ * nvme_auth_generate_digest - Generate TLS PSK digest
+ * @hmac_id: Hash function identifier
+ * @psk: Generated input PSK
+ * @psk_len: Length of @psk
+ * @subsysnqn: NQN of the subsystem
+ * @hostnqn: NQN of the host
+ * @ret_digest: Pointer to the returned digest
+ *
+ * Generate a TLS PSK digest as specified in TP8018 Section 3.6.1.3:
+ *   TLS PSK and PSK identity Derivation
+ *
+ * The PSK digest shall be computed by encoding in Base64 (refer to RFC
+ * 4648) the result of the application of the HMAC function using the hash
+ * function specified in item 4 above (ie the hash function of the cipher
+ * suite associated with the PSK identity) with the PSK as HMAC key to the
+ * concatenation of:
+ * - the NQN of the host (i.e., NQNh) not including the null terminator;
+ * - a space character;
+ * - the NQN of the NVM subsystem (i.e., NQNc) not including the null
+ *   terminator;
+ * - a space character; and
+ * - the seventeen ASCII characters "NVMe-over-Fabrics"
+ * (i.e., <PSK digest> = Base64(HMAC(PSK, NQNh || " " || NQNc || " " ||
+ *  "NVMe-over-Fabrics"))).
+ * The length of the PSK digest depends on the hash function used to compute
+ * it as follows:
+ * - If the SHA-256 hash function is used, the resulting PSK digest is 44
+ *   characters long; or
+ * - If the SHA-384 hash function is used, the resulting PSK digest is 64
+ *   characters long.
+ *
+ * Returns 0 on success with a valid digest pointer in @ret_digest, or a
+ * negative error number on failure.
+ */
+int nvme_auth_generate_digest(u8 hmac_id, u8 *psk, size_t psk_len,
+		char *subsysnqn, char *hostnqn, u8 **ret_digest)
+{
+	struct crypto_shash *tfm;
+	SHASH_DESC_ON_STACK(shash, tfm);
+	u8 *digest, *enc;
+	const char *hmac_name;
+	size_t digest_len, hmac_len;
+	int ret;
+
+	if (WARN_ON(!subsysnqn || !hostnqn))
+		return -EINVAL;
+
+	hmac_name = nvme_auth_hmac_name(hmac_id);
+	if (!hmac_name) {
+		pr_warn("%s: invalid hash algorithm %d\n",
+			__func__, hmac_id);
+		return -EINVAL;
+	}
+
+	switch (nvme_auth_hmac_hash_len(hmac_id)) {
+	case 32:
+		hmac_len = 44;
+		break;
+	case 48:
+		hmac_len = 64;
+		break;
+	default:
+		pr_warn("%s: invalid hash algorithm '%s'\n",
+			__func__, hmac_name);
+		return -EINVAL;
+	}
+
+	enc = kzalloc(hmac_len + 1, GFP_KERNEL);
+	if (!enc)
+		return -ENOMEM;
+
+	tfm = crypto_alloc_shash(hmac_name, 0, 0);
+	if (IS_ERR(tfm)) {
+		ret = PTR_ERR(tfm);
+		goto out_free_enc;
+	}
+
+	digest_len = crypto_shash_digestsize(tfm);
+	digest = kzalloc(digest_len, GFP_KERNEL);
+	if (!digest) {
+		ret = -ENOMEM;
+		goto out_free_tfm;
+	}
+
+	shash->tfm = tfm;
+	ret = crypto_shash_setkey(tfm, psk, psk_len);
+	if (ret)
+		goto out_free_digest;
+
+	ret = crypto_shash_init(shash);
+	if (ret)
+		goto out_free_digest;
+
+	ret = crypto_shash_update(shash, hostnqn, strlen(hostnqn));
+	if (ret)
+		goto out_free_digest;
+
+	ret = crypto_shash_update(shash, " ", 1);
+	if (ret)
+		goto out_free_digest;
+
+	ret = crypto_shash_update(shash, subsysnqn, strlen(subsysnqn));
+	if (ret)
+		goto out_free_digest;
+
+	ret = crypto_shash_update(shash, " NVMe-over-Fabrics", 18);
+	if (ret)
+		goto out_free_digest;
+
+	ret = crypto_shash_final(shash, digest);
+	if (ret)
+		goto out_free_digest;
+
+	ret = base64_encode(digest, digest_len, enc, true, BASE64_STD);
+	if (ret < hmac_len) {
+		ret = -ENOKEY;
+		goto out_free_digest;
+	}
+	*ret_digest = enc;
+	ret = 0;
+
+out_free_digest:
+	kfree_sensitive(digest);
+out_free_tfm:
+	crypto_free_shash(tfm);
+out_free_enc:
+	if (ret)
+		kfree_sensitive(enc);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(nvme_auth_generate_digest);
+
+/**
+ * hkdf_expand_label - HKDF-Expand-Label (RFC 8846 section 7.1)
+ * @hmac_tfm: hash context keyed with pseudorandom key
+ * @label: ASCII label without "tls13 " prefix
+ * @labellen: length of @label
+ * @context: context bytes
+ * @contextlen: length of @context
+ * @okm: output keying material
+ * @okmlen: length of @okm
+ *
+ * Build the TLS 1.3 HkdfLabel structure and invoke hkdf_expand().
+ *
+ * Returns 0 on success with output keying material stored in @okm,
+ * or a negative errno value otherwise.
+ */
+static int hkdf_expand_label(struct crypto_shash *hmac_tfm,
+		const u8 *label, unsigned int labellen,
+		const u8 *context, unsigned int contextlen,
+		u8 *okm, unsigned int okmlen)
+{
+	int err;
+	u8 *info;
+	unsigned int infolen;
+	const char *tls13_prefix = "tls13 ";
+	unsigned int prefixlen = strlen(tls13_prefix);
+
+	if (WARN_ON(labellen > (255 - prefixlen)))
+		return -EINVAL;
+	if (WARN_ON(contextlen > 255))
+		return -EINVAL;
+
+	infolen = 2 + (1 + prefixlen + labellen) + (1 + contextlen);
+	info = kzalloc(infolen, GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	/* HkdfLabel.Length */
+	put_unaligned_be16(okmlen, info);
+
+	/* HkdfLabel.Label */
+	info[2] = prefixlen + labellen;
+	memcpy(info + 3, tls13_prefix, prefixlen);
+	memcpy(info + 3 + prefixlen, label, labellen);
+
+	/* HkdfLabel.Context */
+	info[3 + prefixlen + labellen] = contextlen;
+	memcpy(info + 4 + prefixlen + labellen, context, contextlen);
+
+	err = hkdf_expand(hmac_tfm, info, infolen, okm, okmlen);
+	kfree_sensitive(info);
+	return err;
+}
+
+/**
+ * nvme_auth_derive_tls_psk - Derive TLS PSK
+ * @hmac_id: Hash function identifier
+ * @psk: generated input PSK
+ * @psk_len: size of @psk
+ * @psk_digest: TLS PSK digest
+ * @ret_psk: Pointer to the resulting TLS PSK
+ *
+ * Derive a TLS PSK as specified in TP8018 Section 3.6.1.3:
+ *   TLS PSK and PSK identity Derivation
+ *
+ * The TLS PSK shall be derived as follows from an input PSK
+ * (i.e., either a retained PSK or a generated PSK) and a PSK
+ * identity using the HKDF-Extract and HKDF-Expand-Label operations
+ * (refer to RFC 5869 and RFC 8446) where the hash function is the
+ * one specified by the hash specifier of the PSK identity:
+ * 1. PRK = HKDF-Extract(0, Input PSK); and
+ * 2. TLS PSK = HKDF-Expand-Label(PRK, "nvme-tls-psk", PskIdentityContext, L),
+ * where PskIdentityContext is the hash identifier indicated in
+ * the PSK identity concatenated to a space character and to the
+ * Base64 PSK digest (i.e., "<hash> <PSK digest>") and L is the
+ * output size in bytes of the hash function (i.e., 32 for SHA-256
+ * and 48 for SHA-384).
+ *
+ * Returns 0 on success with a valid psk pointer in @ret_psk or a negative
+ * error number otherwise.
+ */
+int nvme_auth_derive_tls_psk(int hmac_id, u8 *psk, size_t psk_len,
+		u8 *psk_digest, u8 **ret_psk)
+{
+	struct crypto_shash *hmac_tfm;
+	const char *hmac_name;
+	const char *label = "nvme-tls-psk";
+	static const char default_salt[HKDF_MAX_HASHLEN];
+	size_t prk_len;
+	const char *ctx;
+	unsigned char *prk, *tls_key;
+	int ret;
+
+	hmac_name = nvme_auth_hmac_name(hmac_id);
+	if (!hmac_name) {
+		pr_warn("%s: invalid hash algorithm %d\n",
+			__func__, hmac_id);
+		return -EINVAL;
+	}
+	if (hmac_id == NVME_AUTH_HASH_SHA512) {
+		pr_warn("%s: unsupported hash algorithm %s\n",
+			__func__, hmac_name);
+		return -EINVAL;
+	}
+
+	hmac_tfm = crypto_alloc_shash(hmac_name, 0, 0);
+	if (IS_ERR(hmac_tfm))
+		return PTR_ERR(hmac_tfm);
+
+	prk_len = crypto_shash_digestsize(hmac_tfm);
+	prk = kzalloc(prk_len, GFP_KERNEL);
+	if (!prk) {
+		ret = -ENOMEM;
+		goto out_free_shash;
+	}
+
+	if (WARN_ON(prk_len > HKDF_MAX_HASHLEN)) {
+		ret = -EINVAL;
+		goto out_free_prk;
+	}
+	ret = hkdf_extract(hmac_tfm, psk, psk_len,
+			   default_salt, prk_len, prk);
+	if (ret)
+		goto out_free_prk;
+
+	ret = crypto_shash_setkey(hmac_tfm, prk, prk_len);
+	if (ret)
+		goto out_free_prk;
+
+	ctx = kasprintf(GFP_KERNEL, "%02d %s", hmac_id, psk_digest);
+	if (!ctx) {
+		ret = -ENOMEM;
+		goto out_free_prk;
+	}
+
+	tls_key = kzalloc(psk_len, GFP_KERNEL);
+	if (!tls_key) {
+		ret = -ENOMEM;
+		goto out_free_ctx;
+	}
+	ret = hkdf_expand_label(hmac_tfm,
+				label, strlen(label),
+				ctx, strlen(ctx),
+				tls_key, psk_len);
+	if (ret) {
+		kfree(tls_key);
+		goto out_free_ctx;
+	}
+	*ret_psk = tls_key;
+
+out_free_ctx:
+	kfree(ctx);
+out_free_prk:
+	kfree(prk);
+out_free_shash:
+	crypto_free_shash(hmac_tfm);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(nvme_auth_derive_tls_psk);
+
+MODULE_DESCRIPTION("NVMe Authentication framework");
 MODULE_LICENSE("GPL v2");