diff options
Diffstat (limited to 'crypto/asymmetric_keys')
| -rw-r--r-- | crypto/asymmetric_keys/Kconfig | 31 | ||||
| -rw-r--r-- | crypto/asymmetric_keys/Makefile | 25 | ||||
| -rw-r--r-- | crypto/asymmetric_keys/asym_tpm.c | 988 | ||||
| -rw-r--r-- | crypto/asymmetric_keys/asymmetric_keys.h | 3 | ||||
| -rw-r--r-- | crypto/asymmetric_keys/asymmetric_type.c | 43 | ||||
| -rw-r--r-- | crypto/asymmetric_keys/pkcs7_parser.c | 1 | ||||
| -rw-r--r-- | crypto/asymmetric_keys/pkcs8.asn1 | 24 | ||||
| -rw-r--r-- | crypto/asymmetric_keys/pkcs8_parser.c | 184 | ||||
| -rw-r--r-- | crypto/asymmetric_keys/public_key.c | 191 | ||||
| -rw-r--r-- | crypto/asymmetric_keys/signature.c | 95 | ||||
| -rw-r--r-- | crypto/asymmetric_keys/tpm.asn1 | 5 | ||||
| -rw-r--r-- | crypto/asymmetric_keys/tpm_parser.c | 102 | ||||
| -rw-r--r-- | crypto/asymmetric_keys/x509_cert_parser.c | 21 |
13 files changed, 1683 insertions, 30 deletions
diff --git a/crypto/asymmetric_keys/Kconfig b/crypto/asymmetric_keys/Kconfig index f3702e533ff4..be70ca6c85d3 100644 --- a/crypto/asymmetric_keys/Kconfig +++ b/crypto/asymmetric_keys/Kconfig @@ -21,6 +21,18 @@ config ASYMMETRIC_PUBLIC_KEY_SUBTYPE appropriate hash algorithms (such as SHA-1) must be available. ENOPKG will be reported if the requisite algorithm is unavailable. +config ASYMMETRIC_TPM_KEY_SUBTYPE + tristate "Asymmetric TPM backed private key subtype" + depends on TCG_TPM + depends on TRUSTED_KEYS + select CRYPTO_HMAC + select CRYPTO_SHA1 + select CRYPTO_HASH_INFO + help + This option provides support for TPM backed private key type handling. + Operations such as sign, verify, encrypt, decrypt are performed by + the TPM after the private key is loaded. + config X509_CERTIFICATE_PARSER tristate "X.509 certificate parser" depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE @@ -31,6 +43,25 @@ config X509_CERTIFICATE_PARSER data and provides the ability to instantiate a crypto key from a public key packet found inside the certificate. +config PKCS8_PRIVATE_KEY_PARSER + tristate "PKCS#8 private key parser" + depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE + select ASN1 + select OID_REGISTRY + help + This option provides support for parsing PKCS#8 format blobs for + private key data and provides the ability to instantiate a crypto key + from that data. + +config TPM_KEY_PARSER + tristate "TPM private key parser" + depends on ASYMMETRIC_TPM_KEY_SUBTYPE + select ASN1 + help + This option provides support for parsing TPM format blobs for + private key data and provides the ability to instantiate a crypto key + from that data. + config PKCS7_MESSAGE_PARSER tristate "PKCS#7 message parser" depends on X509_CERTIFICATE_PARSER diff --git a/crypto/asymmetric_keys/Makefile b/crypto/asymmetric_keys/Makefile index d4b2e1b2dc65..28b91adba2ae 100644 --- a/crypto/asymmetric_keys/Makefile +++ b/crypto/asymmetric_keys/Makefile @@ -11,6 +11,7 @@ asymmetric_keys-y := \ signature.o obj-$(CONFIG_ASYMMETRIC_PUBLIC_KEY_SUBTYPE) += public_key.o +obj-$(CONFIG_ASYMMETRIC_TPM_KEY_SUBTYPE) += asym_tpm.o # # X.509 Certificate handling @@ -30,6 +31,19 @@ $(obj)/x509.asn1.o: $(obj)/x509.asn1.c $(obj)/x509.asn1.h $(obj)/x509_akid.asn1.o: $(obj)/x509_akid.asn1.c $(obj)/x509_akid.asn1.h # +# PKCS#8 private key handling +# +obj-$(CONFIG_PKCS8_PRIVATE_KEY_PARSER) += pkcs8_key_parser.o +pkcs8_key_parser-y := \ + pkcs8.asn1.o \ + pkcs8_parser.o + +$(obj)/pkcs8_parser.o: $(obj)/pkcs8.asn1.h +$(obj)/pkcs8-asn1.o: $(obj)/pkcs8.asn1.c $(obj)/pkcs8.asn1.h + +clean-files += pkcs8.asn1.c pkcs8.asn1.h + +# # PKCS#7 message handling # obj-$(CONFIG_PKCS7_MESSAGE_PARSER) += pkcs7_message.o @@ -61,3 +75,14 @@ verify_signed_pefile-y := \ $(obj)/mscode_parser.o: $(obj)/mscode.asn1.h $(obj)/mscode.asn1.h $(obj)/mscode.asn1.o: $(obj)/mscode.asn1.c $(obj)/mscode.asn1.h + +# +# TPM private key parsing +# +obj-$(CONFIG_TPM_KEY_PARSER) += tpm_key_parser.o +tpm_key_parser-y := \ + tpm.asn1.o \ + tpm_parser.o + +$(obj)/tpm_parser.o: $(obj)/tpm.asn1.h +$(obj)/tpm.asn1.o: $(obj)/tpm.asn1.c $(obj)/tpm.asn1.h diff --git a/crypto/asymmetric_keys/asym_tpm.c b/crypto/asymmetric_keys/asym_tpm.c new file mode 100644 index 000000000000..5d4c270463f6 --- /dev/null +++ b/crypto/asymmetric_keys/asym_tpm.c @@ -0,0 +1,988 @@ +// SPDX-License-Identifier: GPL-2.0 +#define pr_fmt(fmt) "ASYM-TPM: "fmt +#include <linux/slab.h> +#include <linux/module.h> +#include <linux/export.h> +#include <linux/kernel.h> +#include <linux/seq_file.h> +#include <linux/scatterlist.h> +#include <linux/tpm.h> +#include <linux/tpm_command.h> +#include <crypto/akcipher.h> +#include <crypto/hash.h> +#include <crypto/sha.h> +#include <asm/unaligned.h> +#include <keys/asymmetric-subtype.h> +#include <keys/trusted.h> +#include <crypto/asym_tpm_subtype.h> +#include <crypto/public_key.h> + +#define TPM_ORD_FLUSHSPECIFIC 186 +#define TPM_ORD_LOADKEY2 65 +#define TPM_ORD_UNBIND 30 +#define TPM_ORD_SIGN 60 +#define TPM_LOADKEY2_SIZE 59 +#define TPM_FLUSHSPECIFIC_SIZE 18 +#define TPM_UNBIND_SIZE 63 +#define TPM_SIGN_SIZE 63 + +#define TPM_RT_KEY 0x00000001 + +/* + * Load a TPM key from the blob provided by userspace + */ +static int tpm_loadkey2(struct tpm_buf *tb, + uint32_t keyhandle, unsigned char *keyauth, + const unsigned char *keyblob, int keybloblen, + uint32_t *newhandle) +{ + unsigned char nonceodd[TPM_NONCE_SIZE]; + unsigned char enonce[TPM_NONCE_SIZE]; + unsigned char authdata[SHA1_DIGEST_SIZE]; + uint32_t authhandle = 0; + unsigned char cont = 0; + uint32_t ordinal; + int ret; + + ordinal = htonl(TPM_ORD_LOADKEY2); + + /* session for loading the key */ + ret = oiap(tb, &authhandle, enonce); + if (ret < 0) { + pr_info("oiap failed (%d)\n", ret); + return ret; + } + + /* generate odd nonce */ + ret = tpm_get_random(NULL, nonceodd, TPM_NONCE_SIZE); + if (ret < 0) { + pr_info("tpm_get_random failed (%d)\n", ret); + return ret; + } + + /* calculate authorization HMAC value */ + ret = TSS_authhmac(authdata, keyauth, SHA1_DIGEST_SIZE, enonce, + nonceodd, cont, sizeof(uint32_t), &ordinal, + keybloblen, keyblob, 0, 0); + if (ret < 0) + return ret; + + /* build the request buffer */ + INIT_BUF(tb); + store16(tb, TPM_TAG_RQU_AUTH1_COMMAND); + store32(tb, TPM_LOADKEY2_SIZE + keybloblen); + store32(tb, TPM_ORD_LOADKEY2); + store32(tb, keyhandle); + storebytes(tb, keyblob, keybloblen); + store32(tb, authhandle); + storebytes(tb, nonceodd, TPM_NONCE_SIZE); + store8(tb, cont); + storebytes(tb, authdata, SHA1_DIGEST_SIZE); + + ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE); + if (ret < 0) { + pr_info("authhmac failed (%d)\n", ret); + return ret; + } + + ret = TSS_checkhmac1(tb->data, ordinal, nonceodd, keyauth, + SHA1_DIGEST_SIZE, 0, 0); + if (ret < 0) { + pr_info("TSS_checkhmac1 failed (%d)\n", ret); + return ret; + } + + *newhandle = LOAD32(tb->data, TPM_DATA_OFFSET); + return 0; +} + +/* + * Execute the FlushSpecific TPM command + */ +static int tpm_flushspecific(struct tpm_buf *tb, uint32_t handle) +{ + INIT_BUF(tb); + store16(tb, TPM_TAG_RQU_COMMAND); + store32(tb, TPM_FLUSHSPECIFIC_SIZE); + store32(tb, TPM_ORD_FLUSHSPECIFIC); + store32(tb, handle); + store32(tb, TPM_RT_KEY); + + return trusted_tpm_send(tb->data, MAX_BUF_SIZE); +} + +/* + * Decrypt a blob provided by userspace using a specific key handle. + * The handle is a well known handle or previously loaded by e.g. LoadKey2 + */ +static int tpm_unbind(struct tpm_buf *tb, + uint32_t keyhandle, unsigned char *keyauth, + const unsigned char *blob, uint32_t bloblen, + void *out, uint32_t outlen) +{ + unsigned char nonceodd[TPM_NONCE_SIZE]; + unsigned char enonce[TPM_NONCE_SIZE]; + unsigned char authdata[SHA1_DIGEST_SIZE]; + uint32_t authhandle = 0; + unsigned char cont = 0; + uint32_t ordinal; + uint32_t datalen; + int ret; + + ordinal = htonl(TPM_ORD_UNBIND); + datalen = htonl(bloblen); + + /* session for loading the key */ + ret = oiap(tb, &authhandle, enonce); + if (ret < 0) { + pr_info("oiap failed (%d)\n", ret); + return ret; + } + + /* generate odd nonce */ + ret = tpm_get_random(NULL, nonceodd, TPM_NONCE_SIZE); + if (ret < 0) { + pr_info("tpm_get_random failed (%d)\n", ret); + return ret; + } + + /* calculate authorization HMAC value */ + ret = TSS_authhmac(authdata, keyauth, SHA1_DIGEST_SIZE, enonce, + nonceodd, cont, sizeof(uint32_t), &ordinal, + sizeof(uint32_t), &datalen, + bloblen, blob, 0, 0); + if (ret < 0) + return ret; + + /* build the request buffer */ + INIT_BUF(tb); + store16(tb, TPM_TAG_RQU_AUTH1_COMMAND); + store32(tb, TPM_UNBIND_SIZE + bloblen); + store32(tb, TPM_ORD_UNBIND); + store32(tb, keyhandle); + store32(tb, bloblen); + storebytes(tb, blob, bloblen); + store32(tb, authhandle); + storebytes(tb, nonceodd, TPM_NONCE_SIZE); + store8(tb, cont); + storebytes(tb, authdata, SHA1_DIGEST_SIZE); + + ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE); + if (ret < 0) { + pr_info("authhmac failed (%d)\n", ret); + return ret; + } + + datalen = LOAD32(tb->data, TPM_DATA_OFFSET); + + ret = TSS_checkhmac1(tb->data, ordinal, nonceodd, + keyauth, SHA1_DIGEST_SIZE, + sizeof(uint32_t), TPM_DATA_OFFSET, + datalen, TPM_DATA_OFFSET + sizeof(uint32_t), + 0, 0); + if (ret < 0) { + pr_info("TSS_checkhmac1 failed (%d)\n", ret); + return ret; + } + + memcpy(out, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), + min(outlen, datalen)); + + return datalen; +} + +/* + * Sign a blob provided by userspace (that has had the hash function applied) + * using a specific key handle. The handle is assumed to have been previously + * loaded by e.g. LoadKey2. + * + * Note that the key signature scheme of the used key should be set to + * TPM_SS_RSASSAPKCS1v15_DER. This allows the hashed input to be of any size + * up to key_length_in_bytes - 11 and not be limited to size 20 like the + * TPM_SS_RSASSAPKCS1v15_SHA1 signature scheme. + */ +static int tpm_sign(struct tpm_buf *tb, + uint32_t keyhandle, unsigned char *keyauth, + const unsigned char *blob, uint32_t bloblen, + void *out, uint32_t outlen) +{ + unsigned char nonceodd[TPM_NONCE_SIZE]; + unsigned char enonce[TPM_NONCE_SIZE]; + unsigned char authdata[SHA1_DIGEST_SIZE]; + uint32_t authhandle = 0; + unsigned char cont = 0; + uint32_t ordinal; + uint32_t datalen; + int ret; + + ordinal = htonl(TPM_ORD_SIGN); + datalen = htonl(bloblen); + + /* session for loading the key */ + ret = oiap(tb, &authhandle, enonce); + if (ret < 0) { + pr_info("oiap failed (%d)\n", ret); + return ret; + } + + /* generate odd nonce */ + ret = tpm_get_random(NULL, nonceodd, TPM_NONCE_SIZE); + if (ret < 0) { + pr_info("tpm_get_random failed (%d)\n", ret); + return ret; + } + + /* calculate authorization HMAC value */ + ret = TSS_authhmac(authdata, keyauth, SHA1_DIGEST_SIZE, enonce, + nonceodd, cont, sizeof(uint32_t), &ordinal, + sizeof(uint32_t), &datalen, + bloblen, blob, 0, 0); + if (ret < 0) + return ret; + + /* build the request buffer */ + INIT_BUF(tb); + store16(tb, TPM_TAG_RQU_AUTH1_COMMAND); + store32(tb, TPM_SIGN_SIZE + bloblen); + store32(tb, TPM_ORD_SIGN); + store32(tb, keyhandle); + store32(tb, bloblen); + storebytes(tb, blob, bloblen); + store32(tb, authhandle); + storebytes(tb, nonceodd, TPM_NONCE_SIZE); + store8(tb, cont); + storebytes(tb, authdata, SHA1_DIGEST_SIZE); + + ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE); + if (ret < 0) { + pr_info("authhmac failed (%d)\n", ret); + return ret; + } + + datalen = LOAD32(tb->data, TPM_DATA_OFFSET); + + ret = TSS_checkhmac1(tb->data, ordinal, nonceodd, + keyauth, SHA1_DIGEST_SIZE, + sizeof(uint32_t), TPM_DATA_OFFSET, + datalen, TPM_DATA_OFFSET + sizeof(uint32_t), + 0, 0); + if (ret < 0) { + pr_info("TSS_checkhmac1 failed (%d)\n", ret); + return ret; + } + + memcpy(out, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), + min(datalen, outlen)); + + return datalen; +} +/* + * Maximum buffer size for the BER/DER encoded public key. The public key + * is of the form SEQUENCE { INTEGER n, INTEGER e } where n is a maximum 2048 + * bit key and e is usually 65537 + * The encoding overhead is: + * - max 4 bytes for SEQUENCE + * - max 4 bytes for INTEGER n type/length + * - 257 bytes of n + * - max 2 bytes for INTEGER e type/length + * - 3 bytes of e + */ +#define PUB_KEY_BUF_SIZE (4 + 4 + 257 + 2 + 3) + +/* + * Provide a part of a description of the key for /proc/keys. + */ +static void asym_tpm_describe(const struct key *asymmetric_key, + struct seq_file *m) +{ + struct tpm_key *tk = asymmetric_key->payload.data[asym_crypto]; + + if (!tk) + return; + + seq_printf(m, "TPM1.2/Blob"); +} + +static void asym_tpm_destroy(void *payload0, void *payload3) +{ + struct tpm_key *tk = payload0; + + if (!tk) + return; + + kfree(tk->blob); + tk->blob_len = 0; + + kfree(tk); +} + +/* How many bytes will it take to encode the length */ +static inline uint32_t definite_length(uint32_t len) +{ + if (len <= 127) + return 1; + if (len <= 255) + return 2; + return 3; +} + +static inline uint8_t *encode_tag_length(uint8_t *buf, uint8_t tag, + uint32_t len) +{ + *buf++ = tag; + + if (len <= 127) { + buf[0] = len; + return buf + 1; + } + + if (len <= 255) { + buf[0] = 0x81; + buf[1] = len; + return buf + 2; + } + + buf[0] = 0x82; + put_unaligned_be16(len, buf + 1); + return buf + 3; +} + +static uint32_t derive_pub_key(const void *pub_key, uint32_t len, uint8_t *buf) +{ + uint8_t *cur = buf; + uint32_t n_len = definite_length(len) + 1 + len + 1; + uint32_t e_len = definite_length(3) + 1 + 3; + uint8_t e[3] = { 0x01, 0x00, 0x01 }; + + /* SEQUENCE */ + cur = encode_tag_length(cur, 0x30, n_len + e_len); + /* INTEGER n */ + cur = encode_tag_length(cur, 0x02, len + 1); + cur[0] = 0x00; + memcpy(cur + 1, pub_key, len); + cur += len + 1; + cur = encode_tag_length(cur, 0x02, sizeof(e)); + memcpy(cur, e, sizeof(e)); + cur += sizeof(e); + + return cur - buf; +} + +/* + * Determine the crypto algorithm name. + */ +static int determine_akcipher(const char *encoding, const char *hash_algo, + char alg_name[CRYPTO_MAX_ALG_NAME]) +{ + if (strcmp(encoding, "pkcs1") == 0) { + if (!hash_algo) { + strcpy(alg_name, "pkcs1pad(rsa)"); + return 0; + } + + if (snprintf(alg_name, CRYPTO_MAX_ALG_NAME, "pkcs1pad(rsa,%s)", + hash_algo) >= CRYPTO_MAX_ALG_NAME) + return -EINVAL; + + return 0; + } + + if (strcmp(encoding, "raw") == 0) { + strcpy(alg_name, "rsa"); + return 0; + } + + return -ENOPKG; +} + +/* + * Query information about a key. + */ +static int tpm_key_query(const struct kernel_pkey_params *params, + struct kernel_pkey_query *info) +{ + struct tpm_key *tk = params->key->payload.data[asym_crypto]; + int ret; + char alg_name[CRYPTO_MAX_ALG_NAME]; + struct crypto_akcipher *tfm; + uint8_t der_pub_key[PUB_KEY_BUF_SIZE]; + uint32_t der_pub_key_len; + int len; + + /* TPM only works on private keys, public keys still done in software */ + ret = determine_akcipher(params->encoding, params->hash_algo, alg_name); + if (ret < 0) + return ret; + + tfm = crypto_alloc_akcipher(alg_name, 0, 0); + if (IS_ERR(tfm)) + return PTR_ERR(tfm); + + der_pub_key_len = derive_pub_key(tk->pub_key, tk->pub_key_len, + der_pub_key); + + ret = crypto_akcipher_set_pub_key(tfm, der_pub_key, der_pub_key_len); + if (ret < 0) + goto error_free_tfm; + + len = crypto_akcipher_maxsize(tfm); + + info->key_size = tk->key_len; + info->max_data_size = tk->key_len / 8; + info->max_sig_size = len; + info->max_enc_size = len; + info->max_dec_size = tk->key_len / 8; + + info->supported_ops = KEYCTL_SUPPORTS_ENCRYPT | + KEYCTL_SUPPORTS_DECRYPT | + KEYCTL_SUPPORTS_VERIFY | + KEYCTL_SUPPORTS_SIGN; + + ret = 0; +error_free_tfm: + crypto_free_akcipher(tfm); + pr_devel("<==%s() = %d\n", __func__, ret); + return ret; +} + +/* + * Encryption operation is performed with the public key. Hence it is done + * in software + */ +static int tpm_key_encrypt(struct tpm_key *tk, + struct kernel_pkey_params *params, + const void *in, void *out) +{ + char alg_name[CRYPTO_MAX_ALG_NAME]; + struct crypto_akcipher *tfm; + struct akcipher_request *req; + struct crypto_wait cwait; + struct scatterlist in_sg, out_sg; + uint8_t der_pub_key[PUB_KEY_BUF_SIZE]; + uint32_t der_pub_key_len; + int ret; + + pr_devel("==>%s()\n", __func__); + + ret = determine_akcipher(params->encoding, params->hash_algo, alg_name); + if (ret < 0) + return ret; + + tfm = crypto_alloc_akcipher(alg_name, 0, 0); + if (IS_ERR(tfm)) + return PTR_ERR(tfm); + + der_pub_key_len = derive_pub_key(tk->pub_key, tk->pub_key_len, + der_pub_key); + + ret = crypto_akcipher_set_pub_key(tfm, der_pub_key, der_pub_key_len); + if (ret < 0) + goto error_free_tfm; + + req = akcipher_request_alloc(tfm, GFP_KERNEL); + if (!req) + goto error_free_tfm; + + sg_init_one(&in_sg, in, params->in_len); + sg_init_one(&out_sg, out, params->out_len); + akcipher_request_set_crypt(req, &in_sg, &out_sg, params->in_len, + params->out_len); + crypto_init_wait(&cwait); + akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG | + CRYPTO_TFM_REQ_MAY_SLEEP, + crypto_req_done, &cwait); + + ret = crypto_akcipher_encrypt(req); + ret = crypto_wait_req(ret, &cwait); + + if (ret == 0) + ret = req->dst_len; + + akcipher_request_free(req); +error_free_tfm: + crypto_free_akcipher(tfm); + pr_devel("<==%s() = %d\n", __func__, ret); + return ret; +} + +/* + * Decryption operation is performed with the private key in the TPM. + */ +static int tpm_key_decrypt(struct tpm_key *tk, + struct kernel_pkey_params *params, + const void *in, void *out) +{ + struct tpm_buf *tb; + uint32_t keyhandle; + uint8_t srkauth[SHA1_DIGEST_SIZE]; + uint8_t keyauth[SHA1_DIGEST_SIZE]; + int r; + + pr_devel("==>%s()\n", __func__); + + if (params->hash_algo) + return -ENOPKG; + + if (strcmp(params->encoding, "pkcs1")) + return -ENOPKG; + + tb = kzalloc(sizeof(*tb), GFP_KERNEL); + if (!tb) + return -ENOMEM; + + /* TODO: Handle a non-all zero SRK authorization */ + memset(srkauth, 0, sizeof(srkauth)); + + r = tpm_loadkey2(tb, SRKHANDLE, srkauth, + tk->blob, tk->blob_len, &keyhandle); + if (r < 0) { + pr_devel("loadkey2 failed (%d)\n", r); + goto error; + } + + /* TODO: Handle a non-all zero key authorization */ + memset(keyauth, 0, sizeof(keyauth)); + + r = tpm_unbind(tb, keyhandle, keyauth, + in, params->in_len, out, params->out_len); + if (r < 0) + pr_devel("tpm_unbind failed (%d)\n", r); + + if (tpm_flushspecific(tb, keyhandle) < 0) + pr_devel("flushspecific failed (%d)\n", r); + +error: + kzfree(tb); + pr_devel("<==%s() = %d\n", __func__, r); + return r; +} + +/* + * Hash algorithm OIDs plus ASN.1 DER wrappings [RFC4880 sec 5.2.2]. + */ +static const u8 digest_info_md5[] = { + 0x30, 0x20, 0x30, 0x0c, 0x06, 0x08, + 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x02, 0x05, /* OID */ + 0x05, 0x00, 0x04, 0x10 +}; + +static const u8 digest_info_sha1[] = { + 0x30, 0x21, 0x30, 0x09, 0x06, 0x05, + 0x2b, 0x0e, 0x03, 0x02, 0x1a, + 0x05, 0x00, 0x04, 0x14 +}; + +static const u8 digest_info_rmd160[] = { + 0x30, 0x21, 0x30, 0x09, 0x06, 0x05, + 0x2b, 0x24, 0x03, 0x02, 0x01, + 0x05, 0x00, 0x04, 0x14 +}; + +static const u8 digest_info_sha224[] = { + 0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09, + 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04, + 0x05, 0x00, 0x04, 0x1c +}; + +static const u8 digest_info_sha256[] = { + 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, + 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, + 0x05, 0x00, 0x04, 0x20 +}; + +static const u8 digest_info_sha384[] = { + 0x30, 0x41, 0x30, 0x0d, 0x06, 0x09, + 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02, + 0x05, 0x00, 0x04, 0x30 +}; + +static const u8 digest_info_sha512[] = { + 0x30, 0x51, 0x30, 0x0d, 0x06, 0x09, + 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, + 0x05, 0x00, 0x04, 0x40 +}; + +static const struct asn1_template { + const char *name; + const u8 *data; + size_t size; +} asn1_templates[] = { +#define _(X) { #X, digest_info_##X, sizeof(digest_info_##X) } + _(md5), + _(sha1), + _(rmd160), + _(sha256), + _(sha384), + _(sha512), + _(sha224), + { NULL } +#undef _ +}; + +static const struct asn1_template *lookup_asn1(const char *name) +{ + const struct asn1_template *p; + + for (p = asn1_templates; p->name; p++) + if (strcmp(name, p->name) == 0) + return p; + return NULL; +} + +/* + * Sign operation is performed with the private key in the TPM. + */ +static int tpm_key_sign(struct tpm_key *tk, + struct kernel_pkey_params *params, + const void *in, void *out) +{ + struct tpm_buf *tb; + uint32_t keyhandle; + uint8_t srkauth[SHA1_DIGEST_SIZE]; + uint8_t keyauth[SHA1_DIGEST_SIZE]; + void *asn1_wrapped = NULL; + uint32_t in_len = params->in_len; + int r; + + pr_devel("==>%s()\n", __func__); + + if (strcmp(params->encoding, "pkcs1")) + return -ENOPKG; + + if (params->hash_algo) { + const struct asn1_template *asn1 = + lookup_asn1(params->hash_algo); + + if (!asn1) + return -ENOPKG; + + /* request enough space for the ASN.1 template + input hash */ + asn1_wrapped = kzalloc(in_len + asn1->size, GFP_KERNEL); + if (!asn1_wrapped) + return -ENOMEM; + + /* Copy ASN.1 template, then the input */ + memcpy(asn1_wrapped, asn1->data, asn1->size); + memcpy(asn1_wrapped + asn1->size, in, in_len); + + in = asn1_wrapped; + in_len += asn1->size; + } + + if (in_len > tk->key_len / 8 - 11) { + r = -EOVERFLOW; + goto error_free_asn1_wrapped; + } + + r = -ENOMEM; + tb = kzalloc(sizeof(*tb), GFP_KERNEL); + if (!tb) + goto error_free_asn1_wrapped; + + /* TODO: Handle a non-all zero SRK authorization */ + memset(srkauth, 0, sizeof(srkauth)); + + r = tpm_loadkey2(tb, SRKHANDLE, srkauth, + tk->blob, tk->blob_len, &keyhandle); + if (r < 0) { + pr_devel("loadkey2 failed (%d)\n", r); + goto error_free_tb; + } + + /* TODO: Handle a non-all zero key authorization */ + memset(keyauth, 0, sizeof(keyauth)); + + r = tpm_sign(tb, keyhandle, keyauth, in, in_len, out, params->out_len); + if (r < 0) + pr_devel("tpm_sign failed (%d)\n", r); + + if (tpm_flushspecific(tb, keyhandle) < 0) + pr_devel("flushspecific failed (%d)\n", r); + +error_free_tb: + kzfree(tb); +error_free_asn1_wrapped: + kfree(asn1_wrapped); + pr_devel("<==%s() = %d\n", __func__, r); + return r; +} + +/* + * Do encryption, decryption and signing ops. + */ +static int tpm_key_eds_op(struct kernel_pkey_params *params, + const void *in, void *out) +{ + struct tpm_key *tk = params->key->payload.data[asym_crypto]; + int ret = -EOPNOTSUPP; + + /* Perform the encryption calculation. */ + switch (params->op) { + case kernel_pkey_encrypt: + ret = tpm_key_encrypt(tk, params, in, out); + break; + case kernel_pkey_decrypt: + ret = tpm_key_decrypt(tk, params, in, out); + break; + case kernel_pkey_sign: + ret = tpm_key_sign(tk, params, in, out); + break; + default: + BUG(); + } + + return ret; +} + +/* + * Verify a signature using a public key. + */ +static int tpm_key_verify_signature(const struct key *key, + const struct public_key_signature *sig) +{ + const struct tpm_key *tk = key->payload.data[asym_crypto]; + struct crypto_wait cwait; + struct crypto_akcipher *tfm; + struct akcipher_request *req; + struct scatterlist sig_sg, digest_sg; + char alg_name[CRYPTO_MAX_ALG_NAME]; + uint8_t der_pub_key[PUB_KEY_BUF_SIZE]; + uint32_t der_pub_key_len; + void *output; + unsigned int outlen; + int ret; + + pr_devel("==>%s()\n", __func__); + + BUG_ON(!tk); + BUG_ON(!sig); + BUG_ON(!sig->s); + + if (!sig->digest) + return -ENOPKG; + + ret = determine_akcipher(sig->encoding, sig->hash_algo, alg_name); + if (ret < 0) + return ret; + + tfm = crypto_alloc_akcipher(alg_name, 0, 0); + if (IS_ERR(tfm)) + return PTR_ERR(tfm); + + der_pub_key_len = derive_pub_key(tk->pub_key, tk->pub_key_len, + der_pub_key); + + ret = crypto_akcipher_set_pub_key(tfm, der_pub_key, der_pub_key_len); + if (ret < 0) + goto error_free_tfm; + + ret = -ENOMEM; + req = akcipher_request_alloc(tfm, GFP_KERNEL); + if (!req) + goto error_free_tfm; + + ret = -ENOMEM; + outlen = crypto_akcipher_maxsize(tfm); + output = kmalloc(outlen, GFP_KERNEL); + if (!output) + goto error_free_req; + + sg_init_one(&sig_sg, sig->s, sig->s_size); + sg_init_one(&digest_sg, output, outlen); + akcipher_request_set_crypt(req, &sig_sg, &digest_sg, sig->s_size, + outlen); + crypto_init_wait(&cwait); + akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG | + CRYPTO_TFM_REQ_MAY_SLEEP, + crypto_req_done, &cwait); + + /* Perform the verification calculation. This doesn't actually do the + * verification, but rather calculates the hash expected by the + * signature and returns that to us. + */ + ret = crypto_wait_req(crypto_akcipher_verify(req), &cwait); + if (ret) + goto out_free_output; + + /* Do the actual verification step. */ + if (req->dst_len != sig->digest_size || + memcmp(sig->digest, output, sig->digest_size) != 0) + ret = -EKEYREJECTED; + +out_free_output: + kfree(output); +error_free_req: + akcipher_request_free(req); +error_free_tfm: + crypto_free_akcipher(tfm); + pr_devel("<==%s() = %d\n", __func__, ret); + if (WARN_ON_ONCE(ret > 0)) + ret = -EINVAL; + return ret; +} + +/* + * Parse enough information out of TPM_KEY structure: + * TPM_STRUCT_VER -> 4 bytes + * TPM_KEY_USAGE -> 2 bytes + * TPM_KEY_FLAGS -> 4 bytes + * TPM_AUTH_DATA_USAGE -> 1 byte + * TPM_KEY_PARMS -> variable + * UINT32 PCRInfoSize -> 4 bytes + * BYTE* -> PCRInfoSize bytes + * TPM_STORE_PUBKEY + * UINT32 encDataSize; + * BYTE* -> encDataSize; + * + * TPM_KEY_PARMS: + * TPM_ALGORITHM_ID -> 4 bytes + * TPM_ENC_SCHEME -> 2 bytes + * TPM_SIG_SCHEME -> 2 bytes + * UINT32 parmSize -> 4 bytes + * BYTE* -> variable + */ +static int extract_key_parameters(struct tpm_key *tk) +{ + const void *cur = tk->blob; + uint32_t len = tk->blob_len; + const void *pub_key; + uint32_t sz; + uint32_t key_len; + + if (len < 11) + return -EBADMSG; + + /* Ensure this is a legacy key */ + if (get_unaligned_be16(cur + 4) != 0x0015) + return -EBADMSG; + + /* Skip to TPM_KEY_PARMS */ + cur += 11; + len -= 11; + + if (len < 12) + return -EBADMSG; + + /* Make sure this is an RSA key */ + if (get_unaligned_be32(cur) != 0x00000001) + return -EBADMSG; + + /* Make sure this is TPM_ES_RSAESPKCSv15 encoding scheme */ + if (get_unaligned_be16(cur + 4) != 0x0002) + return -EBADMSG; + + /* Make sure this is TPM_SS_RSASSAPKCS1v15_DER signature scheme */ + if (get_unaligned_be16(cur + 6) != 0x0003) + return -EBADMSG; + + sz = get_unaligned_be32(cur + 8); + if (len < sz + 12) + return -EBADMSG; + + /* Move to TPM_RSA_KEY_PARMS */ + len -= 12; + cur += 12; + + /* Grab the RSA key length */ + key_len = get_unaligned_be32(cur); + + switch (key_len) { + case 512: + case 1024: + case 1536: + case 2048: + break; + default: + return -EINVAL; + } + + /* Move just past TPM_KEY_PARMS */ + cur += sz; + len -= sz; + + if (len < 4) + return -EBADMSG; + + sz = get_unaligned_be32(cur); + if (len < 4 + sz) + return -EBADMSG; + + /* Move to TPM_STORE_PUBKEY */ + cur += 4 + sz; + len -= 4 + sz; + + /* Grab the size of the public key, it should jive with the key size */ + sz = get_unaligned_be32(cur); + if (sz > 256) + return -EINVAL; + + pub_key = cur + 4; + + tk->key_len = key_len; + tk->pub_key = pub_key; + tk->pub_key_len = sz; + + return 0; +} + +/* Given the blob, parse it and load it into the TPM */ +struct tpm_key *tpm_key_create(const void *blob, uint32_t blob_len) +{ + int r; + struct tpm_key *tk; + + r = tpm_is_tpm2(NULL); + if (r < 0) + goto error; + + /* We don't support TPM2 yet */ + if (r > 0) { + r = -ENODEV; + goto error; + } + + r = -ENOMEM; + tk = kzalloc(sizeof(struct tpm_key), GFP_KERNEL); + if (!tk) + goto error; + + tk->blob = kmemdup(blob, blob_len, GFP_KERNEL); + if (!tk->blob) + goto error_memdup; + + tk->blob_len = blob_len; + + r = extract_key_parameters(tk); + if (r < 0) + goto error_extract; + + return tk; + +error_extract: + kfree(tk->blob); + tk->blob_len = 0; +error_memdup: + kfree(tk); +error: + return ERR_PTR(r); +} +EXPORT_SYMBOL_GPL(tpm_key_create); + +/* + * TPM-based asymmetric key subtype + */ +struct asymmetric_key_subtype asym_tpm_subtype = { + .owner = THIS_MODULE, + .name = "asym_tpm", + .name_len = sizeof("asym_tpm") - 1, + .describe = asym_tpm_describe, + .destroy = asym_tpm_destroy, + .query = tpm_key_query, + .eds_op = tpm_key_eds_op, + .verify_signature = tpm_key_verify_signature, +}; +EXPORT_SYMBOL_GPL(asym_tpm_subtype); + +MODULE_DESCRIPTION("TPM based asymmetric key subtype"); +MODULE_AUTHOR("Intel Corporation"); +MODULE_LICENSE("GPL v2"); diff --git a/crypto/asymmetric_keys/asymmetric_keys.h b/crypto/asymmetric_keys/asymmetric_keys.h index ca8e9ac34ce6..7be1ccf4fa9f 100644 --- a/crypto/asymmetric_keys/asymmetric_keys.h +++ b/crypto/asymmetric_keys/asymmetric_keys.h @@ -16,3 +16,6 @@ extern struct asymmetric_key_id *asymmetric_key_hex_to_key_id(const char *id); extern int __asymmetric_key_hex_to_key_id(const char *id, struct asymmetric_key_id *match_id, size_t hexlen); + +extern int asymmetric_key_eds_op(struct kernel_pkey_params *params, + const void *in, void *out); diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c index 26539e9a8bda..69a0788a7de5 100644 --- a/crypto/asymmetric_keys/asymmetric_type.c +++ b/crypto/asymmetric_keys/asymmetric_type.c @@ -18,6 +18,7 @@ #include <linux/slab.h> #include <linux/ctype.h> #include <keys/system_keyring.h> +#include <keys/user-type.h> #include "asymmetric_keys.h" MODULE_LICENSE("GPL"); @@ -538,6 +539,45 @@ out: return ret; } +int asymmetric_key_eds_op(struct kernel_pkey_params *params, + const void *in, void *out) +{ + const struct asymmetric_key_subtype *subtype; + struct key *key = params->key; + int ret; + + pr_devel("==>%s()\n", __func__); + + if (key->type != &key_type_asymmetric) + return -EINVAL; + subtype = asymmetric_key_subtype(key); + if (!subtype || + !key->payload.data[0]) + return -EINVAL; + if (!subtype->eds_op) + return -ENOTSUPP; + + ret = subtype->eds_op(params, in, out); + + pr_devel("<==%s() = %d\n", __func__, ret); + return ret; +} + +static int asymmetric_key_verify_signature(struct kernel_pkey_params *params, + const void *in, const void *in2) +{ + struct public_key_signature sig = { + .s_size = params->in2_len, + .digest_size = params->in_len, + .encoding = params->encoding, + .hash_algo = params->hash_algo, + .digest = (void *)in, + .s = (void *)in2, + }; + + return verify_signature(params->key, &sig); +} + struct key_type key_type_asymmetric = { .name = "asymmetric", .preparse = asymmetric_key_preparse, @@ -548,6 +588,9 @@ struct key_type key_type_asymmetric = { .destroy = asymmetric_key_destroy, .describe = asymmetric_key_describe, .lookup_restriction = asymmetric_lookup_restriction, + .asym_query = query_asymmetric_key, + .asym_eds_op = asymmetric_key_eds_op, + .asym_verify_signature = asymmetric_key_verify_signature, }; EXPORT_SYMBOL_GPL(key_type_asymmetric); diff --git a/crypto/asymmetric_keys/pkcs7_parser.c b/crypto/asymmetric_keys/pkcs7_parser.c index 0f134162cef4..f0d56e1a8b7e 100644 --- a/crypto/asymmetric_keys/pkcs7_parser.c +++ b/crypto/asymmetric_keys/pkcs7_parser.c @@ -271,6 +271,7 @@ int pkcs7_sig_note_pkey_algo(void *context, size_t hdrlen, switch (ctx->last_oid) { case OID_rsaEncryption: ctx->sinfo->sig->pkey_algo = "rsa"; + ctx->sinfo->sig->encoding = "pkcs1"; break; default: printk("Unsupported pkey algo: %u\n", ctx->last_oid); diff --git a/crypto/asymmetric_keys/pkcs8.asn1 b/crypto/asymmetric_keys/pkcs8.asn1 new file mode 100644 index 000000000000..702c41a3c713 --- /dev/null +++ b/crypto/asymmetric_keys/pkcs8.asn1 @@ -0,0 +1,24 @@ +-- +-- This is the unencrypted variant +-- +PrivateKeyInfo ::= SEQUENCE { + version Version, + privateKeyAlgorithm PrivateKeyAlgorithmIdentifier, + privateKey PrivateKey, + attributes [0] IMPLICIT Attributes OPTIONAL +} + +Version ::= INTEGER ({ pkcs8_note_version }) + +PrivateKeyAlgorithmIdentifier ::= AlgorithmIdentifier ({ pkcs8_note_algo }) + +PrivateKey ::= OCTET STRING ({ pkcs8_note_key }) + +Attributes ::= SET OF Attribute + +Attribute ::= ANY + +AlgorithmIdentifier ::= SEQUENCE { + algorithm OBJECT IDENTIFIER ({ pkcs8_note_OID }), + parameters ANY OPTIONAL +} diff --git a/crypto/asymmetric_keys/pkcs8_parser.c b/crypto/asymmetric_keys/pkcs8_parser.c new file mode 100644 index 000000000000..5f6a7ecc9765 --- /dev/null +++ b/crypto/asymmetric_keys/pkcs8_parser.c @@ -0,0 +1,184 @@ +/* PKCS#8 Private Key parser [RFC 5208]. + * + * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ + +#define pr_fmt(fmt) "PKCS8: "fmt +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/export.h> +#include <linux/slab.h> +#include <linux/err.h> +#include <linux/oid_registry.h> +#include <keys/asymmetric-subtype.h> +#include <keys/asymmetric-parser.h> +#include <crypto/public_key.h> +#include "pkcs8.asn1.h" + +struct pkcs8_parse_context { + struct public_key *pub; + unsigned long data; /* Start of data */ + enum OID last_oid; /* Last OID encountered */ + enum OID algo_oid; /* Algorithm OID */ + u32 key_size; + const void *key; +}; + +/* + * Note an OID when we find one for later processing when we know how to + * interpret it. + */ +int pkcs8_note_OID(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + struct pkcs8_parse_context *ctx = context; + + ctx->last_oid = look_up_OID(value, vlen); + if (ctx->last_oid == OID__NR) { + char buffer[50]; + + sprint_oid(value, vlen, buffer, sizeof(buffer)); + pr_info("Unknown OID: [%lu] %s\n", + (unsigned long)value - ctx->data, buffer); + } + return 0; +} + +/* + * Note the version number of the ASN.1 blob. + */ +int pkcs8_note_version(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + if (vlen != 1 || ((const u8 *)value)[0] != 0) { + pr_warn("Unsupported PKCS#8 version\n"); + return -EBADMSG; + } + return 0; +} + +/* + * Note the public algorithm. + */ +int pkcs8_note_algo(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + struct pkcs8_parse_context *ctx = context; + + if (ctx->last_oid != OID_rsaEncryption) + return -ENOPKG; + + ctx->pub->pkey_algo = "rsa"; + return 0; +} + +/* + * Note the key data of the ASN.1 blob. + */ +int pkcs8_note_key(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + struct pkcs8_parse_context *ctx = context; + + ctx->key = value; + ctx->key_size = vlen; + return 0; +} + +/* + * Parse a PKCS#8 private key blob. + */ +static struct public_key *pkcs8_parse(const void *data, size_t datalen) +{ + struct pkcs8_parse_context ctx; + struct public_key *pub; + long ret; + + memset(&ctx, 0, sizeof(ctx)); + + ret = -ENOMEM; + ctx.pub = kzalloc(sizeof(struct public_key), GFP_KERNEL); + if (!ctx.pub) + goto error; + + ctx.data = (unsigned long)data; + + /* Attempt to decode the private key */ + ret = asn1_ber_decoder(&pkcs8_decoder, &ctx, data, datalen); + if (ret < 0) + goto error_decode; + + ret = -ENOMEM; + pub = ctx.pub; + pub->key = kmemdup(ctx.key, ctx.key_size, GFP_KERNEL); + if (!pub->key) + goto error_decode; + + pub->keylen = ctx.key_size; + pub->key_is_private = true; + return pub; + +error_decode: + kfree(ctx.pub); +error: + return ERR_PTR(ret); +} + +/* + * Attempt to parse a data blob for a key as a PKCS#8 private key. + */ +static int pkcs8_key_preparse(struct key_preparsed_payload *prep) +{ + struct public_key *pub; + + pub = pkcs8_parse(prep->data, prep->datalen); + if (IS_ERR(pub)) + return PTR_ERR(pub); + + pr_devel("Cert Key Algo: %s\n", pub->pkey_algo); + pub->id_type = "PKCS8"; + + /* We're pinning the module by being linked against it */ + __module_get(public_key_subtype.owner); + prep->payload.data[asym_subtype] = &public_key_subtype; + prep->payload.data[asym_key_ids] = NULL; + prep->payload.data[asym_crypto] = pub; + prep->payload.data[asym_auth] = NULL; + prep->quotalen = 100; + return 0; +} + +static struct asymmetric_key_parser pkcs8_key_parser = { + .owner = THIS_MODULE, + .name = "pkcs8", + .parse = pkcs8_key_preparse, +}; + +/* + * Module stuff + */ +static int __init pkcs8_key_init(void) +{ + return register_asymmetric_key_parser(&pkcs8_key_parser); +} + +static void __exit pkcs8_key_exit(void) +{ + unregister_asymmetric_key_parser(&pkcs8_key_parser); +} + +module_init(pkcs8_key_init); +module_exit(pkcs8_key_exit); + +MODULE_DESCRIPTION("PKCS#8 certificate parser"); +MODULE_LICENSE("GPL"); diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c index e929fe1e4106..f5d85b47fcc6 100644 --- a/crypto/asymmetric_keys/public_key.c +++ b/crypto/asymmetric_keys/public_key.c @@ -60,6 +60,165 @@ static void public_key_destroy(void *payload0, void *payload3) } /* + * Determine the crypto algorithm name. + */ +static +int software_key_determine_akcipher(const char *encoding, + const char *hash_algo, + const struct public_key *pkey, + char alg_name[CRYPTO_MAX_ALG_NAME]) +{ + int n; + + if (strcmp(encoding, "pkcs1") == 0) { + /* The data wangled by the RSA algorithm is typically padded + * and encoded in some manner, such as EMSA-PKCS1-1_5 [RFC3447 + * sec 8.2]. + */ + if (!hash_algo) + n = snprintf(alg_name, CRYPTO_MAX_ALG_NAME, + "pkcs1pad(%s)", + pkey->pkey_algo); + else + n = snprintf(alg_name, CRYPTO_MAX_ALG_NAME, + "pkcs1pad(%s,%s)", + pkey->pkey_algo, hash_algo); + return n >= CRYPTO_MAX_ALG_NAME ? -EINVAL : 0; + } + + if (strcmp(encoding, "raw") == 0) { + strcpy(alg_name, pkey->pkey_algo); + return 0; + } + + return -ENOPKG; +} + +/* + * Query information about a key. + */ +static int software_key_query(const struct kernel_pkey_params *params, + struct kernel_pkey_query *info) +{ + struct crypto_akcipher *tfm; + struct public_key *pkey = params->key->payload.data[asym_crypto]; + char alg_name[CRYPTO_MAX_ALG_NAME]; + int ret, len; + + ret = software_key_determine_akcipher(params->encoding, + params->hash_algo, + pkey, alg_name); + if (ret < 0) + return ret; + + tfm = crypto_alloc_akcipher(alg_name, 0, 0); + if (IS_ERR(tfm)) + return PTR_ERR(tfm); + + if (pkey->key_is_private) + ret = crypto_akcipher_set_priv_key(tfm, + pkey->key, pkey->keylen); + else + ret = crypto_akcipher_set_pub_key(tfm, + pkey->key, pkey->keylen); + if (ret < 0) + goto error_free_tfm; + + len = crypto_akcipher_maxsize(tfm); + info->key_size = len * 8; + info->max_data_size = len; + info->max_sig_size = len; + info->max_enc_size = len; + info->max_dec_size = len; + info->supported_ops = (KEYCTL_SUPPORTS_ENCRYPT | + KEYCTL_SUPPORTS_VERIFY); + if (pkey->key_is_private) + info->supported_ops |= (KEYCTL_SUPPORTS_DECRYPT | + KEYCTL_SUPPORTS_SIGN); + ret = 0; + +error_free_tfm: + crypto_free_akcipher(tfm); + pr_devel("<==%s() = %d\n", __func__, ret); + return ret; +} + +/* + * Do encryption, decryption and signing ops. + */ +static int software_key_eds_op(struct kernel_pkey_params *params, + const void *in, void *out) +{ + const struct public_key *pkey = params->key->payload.data[asym_crypto]; + struct akcipher_request *req; + struct crypto_akcipher *tfm; + struct crypto_wait cwait; + struct scatterlist in_sg, out_sg; + char alg_name[CRYPTO_MAX_ALG_NAME]; + int ret; + + pr_devel("==>%s()\n", __func__); + + ret = software_key_determine_akcipher(params->encoding, + params->hash_algo, + pkey, alg_name); + if (ret < 0) + return ret; + + tfm = crypto_alloc_akcipher(alg_name, 0, 0); + if (IS_ERR(tfm)) + return PTR_ERR(tfm); + + req = akcipher_request_alloc(tfm, GFP_KERNEL); + if (!req) + goto error_free_tfm; + + if (pkey->key_is_private) + ret = crypto_akcipher_set_priv_key(tfm, + pkey->key, pkey->keylen); + else + ret = crypto_akcipher_set_pub_key(tfm, + pkey->key, pkey->keylen); + if (ret) + goto error_free_req; + + sg_init_one(&in_sg, in, params->in_len); + sg_init_one(&out_sg, out, params->out_len); + akcipher_request_set_crypt(req, &in_sg, &out_sg, params->in_len, + params->out_len); + crypto_init_wait(&cwait); + akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG | + CRYPTO_TFM_REQ_MAY_SLEEP, + crypto_req_done, &cwait); + + /* Perform the encryption calculation. */ + switch (params->op) { + case kernel_pkey_encrypt: + ret = crypto_akcipher_encrypt(req); + break; + case kernel_pkey_decrypt: + ret = crypto_akcipher_decrypt(req); + break; + case kernel_pkey_sign: + ret = crypto_akcipher_sign(req); + break; + default: + BUG(); + } + + ret = crypto_wait_req(ret, &cwait); + if (ret == 0) + ret = req->dst_len; + +error_free_req: + akcipher_request_free(req); +error_free_tfm: + crypto_free_akcipher(tfm); + pr_devel("<==%s() = %d\n", __func__, ret); + return ret; +} + +/* * Verify a signature using a public key. */ int public_key_verify_signature(const struct public_key *pkey, @@ -69,8 +228,7 @@ int public_key_verify_signature(const struct public_key *pkey, struct crypto_akcipher *tfm; struct akcipher_request *req; struct scatterlist sig_sg, digest_sg; - const char *alg_name; - char alg_name_buf[CRYPTO_MAX_ALG_NAME]; + char alg_name[CRYPTO_MAX_ALG_NAME]; void *output; unsigned int outlen; int ret; @@ -81,21 +239,11 @@ int public_key_verify_signature(const struct public_key *pkey, BUG_ON(!sig); BUG_ON(!sig->s); - if (!sig->digest) - return -ENOPKG; - - alg_name = sig->pkey_algo; - if (strcmp(sig->pkey_algo, "rsa") == 0) { - /* The data wangled by the RSA algorithm is typically padded - * and encoded in some manner, such as EMSA-PKCS1-1_5 [RFC3447 - * sec 8.2]. - */ - if (snprintf(alg_name_buf, CRYPTO_MAX_ALG_NAME, - "pkcs1pad(rsa,%s)", sig->hash_algo - ) >= CRYPTO_MAX_ALG_NAME) - return -EINVAL; - alg_name = alg_name_buf; - } + ret = software_key_determine_akcipher(sig->encoding, + sig->hash_algo, + pkey, alg_name); + if (ret < 0) + return ret; tfm = crypto_alloc_akcipher(alg_name, 0, 0); if (IS_ERR(tfm)) @@ -106,7 +254,12 @@ int public_key_verify_signature(const struct public_key *pkey, if (!req) goto error_free_tfm; - ret = crypto_akcipher_set_pub_key(tfm, pkey->key, pkey->keylen); + if (pkey->key_is_private) + ret = crypto_akcipher_set_priv_key(tfm, + pkey->key, pkey->keylen); + else + ret = crypto_akcipher_set_pub_key(tfm, + pkey->key, pkey->keylen); if (ret) goto error_free_req; @@ -167,6 +320,8 @@ struct asymmetric_key_subtype public_key_subtype = { .name_len = sizeof("public_key") - 1, .describe = public_key_describe, .destroy = public_key_destroy, + .query = software_key_query, + .eds_op = software_key_eds_op, .verify_signature = public_key_verify_signature_2, }; EXPORT_SYMBOL_GPL(public_key_subtype); diff --git a/crypto/asymmetric_keys/signature.c b/crypto/asymmetric_keys/signature.c index 28198314bc39..ad95a58c6642 100644 --- a/crypto/asymmetric_keys/signature.c +++ b/crypto/asymmetric_keys/signature.c @@ -16,7 +16,9 @@ #include <linux/export.h> #include <linux/err.h> #include <linux/slab.h> +#include <linux/keyctl.h> #include <crypto/public_key.h> +#include <keys/user-type.h> #include "asymmetric_keys.h" /* @@ -37,6 +39,99 @@ void public_key_signature_free(struct public_key_signature *sig) EXPORT_SYMBOL_GPL(public_key_signature_free); /** + * query_asymmetric_key - Get information about an aymmetric key. + * @params: Various parameters. + * @info: Where to put the information. + */ +int query_asymmetric_key(const struct kernel_pkey_params *params, + struct kernel_pkey_query *info) +{ + const struct asymmetric_key_subtype *subtype; + struct key *key = params->key; + int ret; + + pr_devel("==>%s()\n", __func__); + + if (key->type != &key_type_asymmetric) + return -EINVAL; + subtype = asymmetric_key_subtype(key); + if (!subtype || + !key->payload.data[0]) + return -EINVAL; + if (!subtype->query) + return -ENOTSUPP; + + ret = subtype->query(params, info); + + pr_devel("<==%s() = %d\n", __func__, ret); + return ret; +} +EXPORT_SYMBOL_GPL(query_asymmetric_key); + +/** + * encrypt_blob - Encrypt data using an asymmetric key + * @params: Various parameters + * @data: Data blob to be encrypted, length params->data_len + * @enc: Encrypted data buffer, length params->enc_len + * + * Encrypt the specified data blob using the private key specified by + * params->key. The encrypted data is wrapped in an encoding if + * params->encoding is specified (eg. "pkcs1"). + * + * Returns the length of the data placed in the encrypted data buffer or an + * error. + */ +int encrypt_blob(struct kernel_pkey_params *params, + const void *data, void *enc) +{ + params->op = kernel_pkey_encrypt; + return asymmetric_key_eds_op(params, data, enc); +} +EXPORT_SYMBOL_GPL(encrypt_blob); + +/** + * decrypt_blob - Decrypt data using an asymmetric key + * @params: Various parameters + * @enc: Encrypted data to be decrypted, length params->enc_len + * @data: Decrypted data buffer, length params->data_len + * + * Decrypt the specified data blob using the private key specified by + * params->key. The decrypted data is wrapped in an encoding if + * params->encoding is specified (eg. "pkcs1"). + * + * Returns the length of the data placed in the decrypted data buffer or an + * error. + */ +int decrypt_blob(struct kernel_pkey_params *params, + const void *enc, void *data) +{ + params->op = kernel_pkey_decrypt; + return asymmetric_key_eds_op(params, enc, data); +} +EXPORT_SYMBOL_GPL(decrypt_blob); + +/** + * create_signature - Sign some data using an asymmetric key + * @params: Various parameters + * @data: Data blob to be signed, length params->data_len + * @enc: Signature buffer, length params->enc_len + * + * Sign the specified data blob using the private key specified by params->key. + * The signature is wrapped in an encoding if params->encoding is specified + * (eg. "pkcs1"). If the encoding needs to know the digest type, this can be + * passed through params->hash_algo (eg. "sha1"). + * + * Returns the length of the data placed in the signature buffer or an error. + */ +int create_signature(struct kernel_pkey_params *params, + const void *data, void *enc) +{ + params->op = kernel_pkey_sign; + return asymmetric_key_eds_op(params, data, enc); +} +EXPORT_SYMBOL_GPL(create_signature); + +/** * verify_signature - Initiate the use of an asymmetric key to verify a signature * @key: The asymmetric key to verify against * @sig: The signature to check diff --git a/crypto/asymmetric_keys/tpm.asn1 b/crypto/asymmetric_keys/tpm.asn1 new file mode 100644 index 000000000000..d7f194232f30 --- /dev/null +++ b/crypto/asymmetric_keys/tpm.asn1 @@ -0,0 +1,5 @@ +-- +-- Unencryted TPM Blob. For details of the format, see: +-- http://david.woodhou.se/draft-woodhouse-cert-best-practice.html#I-D.mavrogiannopoulos-tpmuri +-- +PrivateKeyInfo ::= OCTET STRING ({ tpm_note_key }) diff --git a/crypto/asymmetric_keys/tpm_parser.c b/crypto/asymmetric_keys/tpm_parser.c new file mode 100644 index 000000000000..96405d8dcd98 --- /dev/null +++ b/crypto/asymmetric_keys/tpm_parser.c @@ -0,0 +1,102 @@ +// SPDX-License-Identifier: GPL-2.0 +#define pr_fmt(fmt) "TPM-PARSER: "fmt +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/export.h> +#include <linux/slab.h> +#include <linux/err.h> +#include <keys/asymmetric-subtype.h> +#include <keys/asymmetric-parser.h> +#include <crypto/asym_tpm_subtype.h> +#include "tpm.asn1.h" + +struct tpm_parse_context { + const void *blob; + u32 blob_len; +}; + +/* + * Note the key data of the ASN.1 blob. + */ +int tpm_note_key(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + struct tpm_parse_context *ctx = context; + + ctx->blob = value; + ctx->blob_len = vlen; + + return 0; +} + +/* + * Parse a TPM-encrypted private key blob. + */ +static struct tpm_key *tpm_parse(const void *data, size_t datalen) +{ + struct tpm_parse_context ctx; + long ret; + + memset(&ctx, 0, sizeof(ctx)); + + /* Attempt to decode the private key */ + ret = asn1_ber_decoder(&tpm_decoder, &ctx, data, datalen); + if (ret < 0) + goto error; + + return tpm_key_create(ctx.blob, ctx.blob_len); + +error: + return ERR_PTR(ret); +} +/* + * Attempt to parse a data blob for a key as a TPM private key blob. + */ +static int tpm_key_preparse(struct key_preparsed_payload *prep) +{ + struct tpm_key *tk; + + /* + * TPM 1.2 keys are max 2048 bits long, so assume the blob is no + * more than 4x that + */ + if (prep->datalen > 256 * 4) + return -EMSGSIZE; + + tk = tpm_parse(prep->data, prep->datalen); + + if (IS_ERR(tk)) + return PTR_ERR(tk); + + /* We're pinning the module by being linked against it */ + __module_get(asym_tpm_subtype.owner); + prep->payload.data[asym_subtype] = &asym_tpm_subtype; + prep->payload.data[asym_key_ids] = NULL; + prep->payload.data[asym_crypto] = tk; + prep->payload.data[asym_auth] = NULL; + prep->quotalen = 100; + return 0; +} + +static struct asymmetric_key_parser tpm_key_parser = { + .owner = THIS_MODULE, + .name = "tpm_parser", + .parse = tpm_key_preparse, +}; + +static int __init tpm_key_init(void) +{ + return register_asymmetric_key_parser(&tpm_key_parser); +} + +static void __exit tpm_key_exit(void) +{ + unregister_asymmetric_key_parser(&tpm_key_parser); +} + +module_init(tpm_key_init); +module_exit(tpm_key_exit); + +MODULE_DESCRIPTION("TPM private key-blob parser"); +MODULE_LICENSE("GPL v2"); diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c index b6cabac4b62b..991f4d735a4e 100644 --- a/crypto/asymmetric_keys/x509_cert_parser.c +++ b/crypto/asymmetric_keys/x509_cert_parser.c @@ -199,35 +199,32 @@ int x509_note_pkey_algo(void *context, size_t hdrlen, case OID_md4WithRSAEncryption: ctx->cert->sig->hash_algo = "md4"; - ctx->cert->sig->pkey_algo = "rsa"; - break; + goto rsa_pkcs1; case OID_sha1WithRSAEncryption: ctx->cert->sig->hash_algo = "sha1"; - ctx->cert->sig->pkey_algo = "rsa"; - break; + goto rsa_pkcs1; case OID_sha256WithRSAEncryption: ctx->cert->sig->hash_algo = "sha256"; - ctx->cert->sig->pkey_algo = "rsa"; - break; + goto rsa_pkcs1; case OID_sha384WithRSAEncryption: ctx->cert->sig->hash_algo = "sha384"; - ctx->cert->sig->pkey_algo = "rsa"; - break; + goto rsa_pkcs1; case OID_sha512WithRSAEncryption: ctx->cert->sig->hash_algo = "sha512"; - ctx->cert->sig->pkey_algo = "rsa"; - break; + goto rsa_pkcs1; case OID_sha224WithRSAEncryption: ctx->cert->sig->hash_algo = "sha224"; - ctx->cert->sig->pkey_algo = "rsa"; - break; + goto rsa_pkcs1; } +rsa_pkcs1: + ctx->cert->sig->pkey_algo = "rsa"; + ctx->cert->sig->encoding = "pkcs1"; ctx->algo_oid = ctx->last_oid; return 0; } |