From 223db480c54de8ec47b3b0b4c6066b58342a5ad4 Mon Sep 17 00:00:00 2001 From: Radu Alexe Date: Wed, 3 May 2017 16:17:13 +0300 Subject: [PATCH] crypto: add support for TLS 1.0 record encryption MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This patch adds kernel support for encryption/decryption of TLS 1.0 records using block ciphers. Implementation is similar to authenc in the sense that the base algorithms (AES, SHA1) are combined in a template to produce TLS encapsulation frames. The composite algorithm will be called "tls10(hmac(),cbc())". The cipher and hmac keys are wrapped in the same format used by authenc.c. Signed-off-by: Radu Alexe Signed-off-by: Cristian Stoica Signed-off-by: Horia Geantă --- crypto/Kconfig | 20 ++ crypto/Makefile | 1 + crypto/tcrypt.c | 3 + crypto/testmgr.c | 238 ++++++++++++++++++++++ crypto/testmgr.h | 224 ++++++++++++++++++++ crypto/tls.c | 607 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 6 files changed, 1093 insertions(+) create mode 100644 crypto/tls.c --- a/crypto/Kconfig +++ b/crypto/Kconfig @@ -349,6 +349,26 @@ config CRYPTO_ECHAINIV a sequence number xored with a salt. This is the default algorithm for CBC. +config CRYPTO_TLS + tristate "TLS support" + select CRYPTO_AEAD + select CRYPTO_BLKCIPHER + select CRYPTO_MANAGER + select CRYPTO_HASH + select CRYPTO_NULL + select CRYPTO_AUTHENC + help + Support for TLS 1.0 record encryption and decryption + + This module adds support for encryption/decryption of TLS 1.0 frames + using blockcipher algorithms. The name of the resulting algorithm is + "tls10(hmac(),cbc())". By default, the generic base + algorithms are used (e.g. aes-generic, sha1-generic), but hardware + accelerated versions will be used automatically if available. + + User-space applications (OpenSSL, GnuTLS) can offload TLS 1.0 + operations through AF_ALG or cryptodev interfaces + comment "Block modes" config CRYPTO_CBC --- a/crypto/Makefile +++ b/crypto/Makefile @@ -144,6 +144,7 @@ obj-$(CONFIG_CRYPTO_CRC32) += crc32_gene obj-$(CONFIG_CRYPTO_CRCT10DIF) += crct10dif_common.o crct10dif_generic.o obj-$(CONFIG_CRYPTO_AUTHENC) += authenc.o authencesn.o obj-$(CONFIG_CRYPTO_LZO) += lzo.o lzo-rle.o +obj-$(CONFIG_CRYPTO_TLS) += tls.o obj-$(CONFIG_CRYPTO_LZ4) += lz4.o obj-$(CONFIG_CRYPTO_LZ4HC) += lz4hc.o obj-$(CONFIG_CRYPTO_XXHASH) += xxhash_generic.o --- a/crypto/tcrypt.c +++ b/crypto/tcrypt.c @@ -2040,6 +2040,9 @@ static int do_test(const char *alg, u32 ret += tcrypt_test("cbc(sm4)"); ret += tcrypt_test("ctr(sm4)"); break; + case 192: + ret += tcrypt_test("tls10(hmac(sha1),cbc(aes))"); + break; case 200: test_cipher_speed("ecb(aes)", ENCRYPT, sec, NULL, 0, speed_template_16_24_32); --- a/crypto/testmgr.c +++ b/crypto/testmgr.c @@ -111,6 +111,13 @@ struct drbg_test_suite { unsigned int count; }; +struct tls_test_suite { + struct { + struct tls_testvec *vecs; + unsigned int count; + } enc, dec; +}; + struct akcipher_test_suite { const struct akcipher_testvec *vecs; unsigned int count; @@ -135,6 +142,7 @@ struct alg_test_desc { struct hash_test_suite hash; struct cprng_test_suite cprng; struct drbg_test_suite drbg; + struct tls_test_suite tls; struct akcipher_test_suite akcipher; struct kpp_test_suite kpp; } suite; @@ -2294,6 +2302,227 @@ static int test_aead(const char *driver, return 0; } +static int __test_tls(struct crypto_aead *tfm, int enc, + struct tls_testvec *template, unsigned int tcount, + const bool diff_dst) +{ + const char *algo = crypto_tfm_alg_driver_name(crypto_aead_tfm(tfm)); + unsigned int i, k, authsize; + char *q; + struct aead_request *req; + struct scatterlist *sg; + struct scatterlist *sgout; + const char *e, *d; + struct crypto_wait wait; + void *input; + void *output; + void *assoc; + char *iv; + char *key; + char *xbuf[XBUFSIZE]; + char *xoutbuf[XBUFSIZE]; + char *axbuf[XBUFSIZE]; + int ret = -ENOMEM; + + if (testmgr_alloc_buf(xbuf)) + goto out_noxbuf; + + if (diff_dst && testmgr_alloc_buf(xoutbuf)) + goto out_nooutbuf; + + if (testmgr_alloc_buf(axbuf)) + goto out_noaxbuf; + + iv = kzalloc(MAX_IVLEN, GFP_KERNEL); + if (!iv) + goto out_noiv; + + key = kzalloc(MAX_KEYLEN, GFP_KERNEL); + if (!key) + goto out_nokey; + + sg = kmalloc(sizeof(*sg) * 8 * (diff_dst ? 2 : 1), GFP_KERNEL); + if (!sg) + goto out_nosg; + + sgout = sg + 8; + + d = diff_dst ? "-ddst" : ""; + e = enc ? "encryption" : "decryption"; + + crypto_init_wait(&wait); + + req = aead_request_alloc(tfm, GFP_KERNEL); + if (!req) { + pr_err("alg: tls%s: Failed to allocate request for %s\n", + d, algo); + goto out; + } + + aead_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG, + crypto_req_done, &wait); + + for (i = 0; i < tcount; i++) { + input = xbuf[0]; + assoc = axbuf[0]; + + ret = -EINVAL; + if (WARN_ON(template[i].ilen > PAGE_SIZE || + template[i].alen > PAGE_SIZE)) + goto out; + + memcpy(assoc, template[i].assoc, template[i].alen); + memcpy(input, template[i].input, template[i].ilen); + + if (template[i].iv) + memcpy(iv, template[i].iv, MAX_IVLEN); + else + memset(iv, 0, MAX_IVLEN); + + crypto_aead_clear_flags(tfm, ~0); + + if (template[i].klen > MAX_KEYLEN) { + pr_err("alg: aead%s: setkey failed on test %d for %s: key size %d > %d\n", + d, i, algo, template[i].klen, MAX_KEYLEN); + ret = -EINVAL; + goto out; + } + memcpy(key, template[i].key, template[i].klen); + + ret = crypto_aead_setkey(tfm, key, template[i].klen); + if (!ret == template[i].fail) { + pr_err("alg: tls%s: setkey failed on test %d for %s: flags=%x\n", + d, i, algo, crypto_aead_get_flags(tfm)); + goto out; + } else if (ret) + continue; + + authsize = 20; + ret = crypto_aead_setauthsize(tfm, authsize); + if (ret) { + pr_err("alg: aead%s: Failed to set authsize to %u on test %d for %s\n", + d, authsize, i, algo); + goto out; + } + + k = !!template[i].alen; + sg_init_table(sg, k + 1); + sg_set_buf(&sg[0], assoc, template[i].alen); + sg_set_buf(&sg[k], input, (enc ? template[i].rlen : + template[i].ilen)); + output = input; + + if (diff_dst) { + sg_init_table(sgout, k + 1); + sg_set_buf(&sgout[0], assoc, template[i].alen); + + output = xoutbuf[0]; + sg_set_buf(&sgout[k], output, + (enc ? template[i].rlen : template[i].ilen)); + } + + aead_request_set_crypt(req, sg, (diff_dst) ? sgout : sg, + template[i].ilen, iv); + + aead_request_set_ad(req, template[i].alen); + + ret = crypto_wait_req(enc ? crypto_aead_encrypt(req) + : crypto_aead_decrypt(req), &wait); + + switch (ret) { + case 0: + if (template[i].novrfy) { + /* verification was supposed to fail */ + pr_err("alg: tls%s: %s failed on test %d for %s: ret was 0, expected -EBADMSG\n", + d, e, i, algo); + /* so really, we got a bad message */ + ret = -EBADMSG; + goto out; + } + break; + case -EBADMSG: + /* verification failure was expected */ + if (template[i].novrfy) + continue; + /* fall through */ + default: + pr_err("alg: tls%s: %s failed on test %d for %s: ret=%d\n", + d, e, i, algo, -ret); + goto out; + } + + q = output; + if (memcmp(q, template[i].result, template[i].rlen)) { + pr_err("alg: tls%s: Test %d failed on %s for %s\n", + d, i, e, algo); + hexdump(q, template[i].rlen); + pr_err("should be:\n"); + hexdump(template[i].result, template[i].rlen); + ret = -EINVAL; + goto out; + } + } + +out: + aead_request_free(req); + + kfree(sg); +out_nosg: + kfree(key); +out_nokey: + kfree(iv); +out_noiv: + testmgr_free_buf(axbuf); +out_noaxbuf: + if (diff_dst) + testmgr_free_buf(xoutbuf); +out_nooutbuf: + testmgr_free_buf(xbuf); +out_noxbuf: + return ret; +} + +static int test_tls(struct crypto_aead *tfm, int enc, + struct tls_testvec *template, unsigned int tcount) +{ + int ret; + /* test 'dst == src' case */ + ret = __test_tls(tfm, enc, template, tcount, false); + if (ret) + return ret; + /* test 'dst != src' case */ + return __test_tls(tfm, enc, template, tcount, true); +} + +static int alg_test_tls(const struct alg_test_desc *desc, const char *driver, + u32 type, u32 mask) +{ + struct crypto_aead *tfm; + int err = 0; + + tfm = crypto_alloc_aead(driver, type, mask); + if (IS_ERR(tfm)) { + pr_err("alg: aead: Failed to load transform for %s: %ld\n", + driver, PTR_ERR(tfm)); + return PTR_ERR(tfm); + } + + if (desc->suite.tls.enc.vecs) { + err = test_tls(tfm, ENCRYPT, desc->suite.tls.enc.vecs, + desc->suite.tls.enc.count); + if (err) + goto out; + } + + if (!err && desc->suite.tls.dec.vecs) + err = test_tls(tfm, DECRYPT, desc->suite.tls.dec.vecs, + desc->suite.tls.dec.count); + +out: + crypto_free_aead(tfm); + return err; +} + static int alg_test_aead(const struct alg_test_desc *desc, const char *driver, u32 type, u32 mask) { @@ -5042,6 +5271,15 @@ static const struct alg_test_desc alg_te .hash = __VECS(tgr192_tv_template) } }, { + .alg = "tls10(hmac(sha1),cbc(aes))", + .test = alg_test_tls, + .suite = { + .tls = { + .enc = __VECS(tls_enc_tv_template), + .dec = __VECS(tls_dec_tv_template) + } + } + }, { .alg = "vmac64(aes)", .test = alg_test_hash, .suite = { --- a/crypto/testmgr.h +++ b/crypto/testmgr.h @@ -21,7 +21,12 @@ #define _CRYPTO_TESTMGR_H #include +#include +#define MAX_DIGEST_SIZE 64 +#define MAX_TAP 8 + +#define MAX_KEYLEN 160 #define MAX_IVLEN 32 /* @@ -140,6 +145,20 @@ struct drbg_testvec { size_t expectedlen; }; +struct tls_testvec { + char *key; /* wrapped keys for encryption and authentication */ + char *iv; /* initialization vector */ + char *input; /* input data */ + char *assoc; /* associated data: seq num, type, version, input len */ + char *result; /* result data */ + unsigned char fail; /* the test failure is expected */ + unsigned char novrfy; /* dec verification failure expected */ + unsigned char klen; /* key length */ + unsigned short ilen; /* input data length */ + unsigned short alen; /* associated data length */ + unsigned short rlen; /* result length */ +}; + struct akcipher_testvec { const unsigned char *key; const unsigned char *params; @@ -171,6 +190,211 @@ struct kpp_testvec { static const char zeroed_string[48]; /* + * TLS1.0 synthetic test vectors + */ +static struct tls_testvec tls_enc_tv_template[] = { + { +#ifdef __LITTLE_ENDIAN + .key = "\x08\x00" /* rta length */ + "\x01\x00" /* rta type */ +#else + .key = "\x00\x08" /* rta length */ + "\x00\x01" /* rta type */ +#endif + "\x00\x00\x00\x10" /* enc key length */ + "authenticationkey20benckeyis16_bytes", + .klen = 8 + 20 + 16, + .iv = "iv0123456789abcd", + .input = "Single block msg", + .ilen = 16, + .assoc = "\x00\x01\x02\x03\x04\x05\x06\x07" + "\x00\x03\x01\x00\x10", + .alen = 13, + .result = "\xd5\xac\xb\xd2\xac\xad\x3f\xb1" + "\x59\x79\x1e\x91\x5f\x52\x14\x9c" + "\xc0\x75\xd8\x4c\x97\x0f\x07\x73" + "\xdc\x89\x47\x49\x49\xcb\x30\x6b" + "\x1b\x45\x23\xa1\xd0\x51\xcf\x02" + "\x2e\xa8\x5d\xa0\xfe\xca\x82\x61", + .rlen = 16 + 20 + 12, + }, { +#ifdef __LITTLE_ENDIAN + .key = "\x08\x00" /* rta length */ + "\x01\x00" /* rta type */ +#else + .key = "\x00\x08" /* rta length */ + "\x00\x01" /* rta type */ +#endif + "\x00\x00\x00\x10" /* enc key length */ + "authenticationkey20benckeyis16_bytes", + .klen = 8 + 20 + 16, + .iv = "iv0123456789abcd", + .input = "", + .ilen = 0, + .assoc = "\x00\x01\x02\x03\x04\x05\x06\x07" + "\x00\x03\x01\x00\x00", + .alen = 13, + .result = "\x58\x2a\x11\xc\x86\x8e\x4b\x67" + "\x2d\x16\x26\x1a\xac\x4b\xe2\x1a" + "\xe9\x6a\xcc\x4d\x6f\x79\x8a\x45" + "\x1f\x4e\x27\xf2\xa7\x59\xb4\x5a", + .rlen = 20 + 12, + }, { +#ifdef __LITTLE_ENDIAN + .key = "\x08\x00" /* rta length */ + "\x01\x00" /* rta type */ +#else + .key = "\x00\x08" /* rta length */ + "\x00\x01" /* rta type */ +#endif + "\x00\x00\x00\x10" /* enc key length */ + "authenticationkey20benckeyis16_bytes", + .klen = 8 + 20 + 16, + .iv = "iv0123456789abcd", + .input = "285 bytes plaintext285 bytes plaintext285 bytes" + " plaintext285 bytes plaintext285 bytes plaintext285" + " bytes plaintext285 bytes plaintext285 bytes" + " plaintext285 bytes plaintext285 bytes plaintext285" + " bytes plaintext285 bytes plaintext285 bytes" + " plaintext285 bytes plaintext285 bytes plaintext285" + " bytes plaintext285 bytes plaintext", + .ilen = 285, + .assoc = "\x00\x01\x02\x03\x04\x05\x06\x07" + "\x00\x03\x01\x01\x1d", + .alen = 13, + .result = "\x80\x23\x82\x44\x14\x2a\x1d\x94\xc\xc2\x1d\xd" + "\x3a\x32\x89\x4c\x57\x30\xa8\x89\x76\x46\xcc\x90" + "\x1d\x88\xb8\xa6\x1a\x58\xe\x2d\xeb\x2c\xc7\x3a" + "\x52\x4e\xdb\xb3\x1e\x83\x11\xf5\x3c\xce\x6e\x94" + "\xd3\x26\x6a\x9a\xd\xbd\xc7\x98\xb9\xb3\x3a\x51" + "\x1e\x4\x84\x8a\x8f\x54\x9a\x51\x69\x9c\xce\x31" + "\x8d\x5d\x8b\xee\x5f\x70\xc\xc9\xb8\x50\x54\xf8" + "\xb2\x4a\x7a\xcd\xeb\x7a\x82\x81\xc6\x41\xc8\x50" + "\x91\x8d\xc8\xed\xcd\x40\x8f\x55\xd1\xec\xc9\xac" + "\x15\x18\xf9\x20\xa0\xed\x18\xa1\xe3\x56\xe3\x14" + "\xe5\xe8\x66\x63\x20\xed\xe4\x62\x9d\xa3\xa4\x1d" + "\x81\x89\x18\xf2\x36\xae\xc8\x8a\x2b\xbc\xc3\xb8" + "\x80\xf\x97\x21\x36\x39\x8\x84\x23\x18\x9e\x9c" + "\x72\x32\x75\x2d\x2e\xf9\x60\xb\xe8\xcc\xd9\x74" + "\x4\x1b\x8e\x99\xc1\x94\xee\xd0\xac\x4e\xfc\x7e" + "\xf1\x96\xb3\xe7\x14\xb8\xf2\xc\x25\x97\x82\x6b" + "\xbd\x0\x65\xab\x5c\xe3\x16\xfb\x68\xef\xea\x9d" + "\xff\x44\x1d\x2a\x44\xf5\xc8\x56\x77\xb7\xbf\x13" + "\xc8\x54\xdb\x92\xfe\x16\x4c\xbe\x18\xe9\xb\x8d" + "\xb\xd4\x43\x58\x43\xaa\xf4\x3\x80\x97\x62\xd5" + "\xdf\x3c\x28\xaa\xee\x48\x4b\x55\x41\x1b\x31\x2" + "\xbe\xa0\x1c\xbd\xb7\x22\x2a\xe5\x53\x72\x73\x20" + "\x44\x4f\xe6\x1\x2b\x34\x33\x11\x7d\xfb\x10\xc1" + "\x66\x7c\xa6\xf4\x48\x36\x5e\x2\xda\x41\x4b\x3e" + "\xe7\x80\x17\x17\xce\xf1\x3e\x6a\x8e\x26\xf3\xb7" + "\x2b\x85\xd\x31\x8d\xba\x6c\x22\xb4\x28\x55\x7e" + "\x2a\x9e\x26\xf1\x3d\x21\xac\x65", + .rlen = 285 + 20 + 15, + } +}; + +static struct tls_testvec tls_dec_tv_template[] = { + { +#ifdef __LITTLE_ENDIAN + .key = "\x08\x00" /* rta length */ + "\x01\x00" /* rta type */ +#else + .key = "\x00\x08" /* rta length */ + "\x00\x01" /* rta type */ +#endif + "\x00\x00\x00\x10" /* enc key length */ + "authenticationkey20benckeyis16_bytes", + .klen = 8 + 20 + 16, + .iv = "iv0123456789abcd", + .input = "\xd5\xac\xb\xd2\xac\xad\x3f\xb1" + "\x59\x79\x1e\x91\x5f\x52\x14\x9c" + "\xc0\x75\xd8\x4c\x97\x0f\x07\x73" + "\xdc\x89\x47\x49\x49\xcb\x30\x6b" + "\x1b\x45\x23\xa1\xd0\x51\xcf\x02" + "\x2e\xa8\x5d\xa0\xfe\xca\x82\x61", + .ilen = 16 + 20 + 12, + .assoc = "\x00\x01\x02\x03\x04\x05\x06\x07" + "\x00\x03\x01\x00\x30", + .alen = 13, + .result = "Single block msg", + .rlen = 16, + }, { +#ifdef __LITTLE_ENDIAN + .key = "\x08\x00" /* rta length */ + "\x01\x00" /* rta type */ +#else + .key = "\x00\x08" /* rta length */ + "\x00\x01" /* rta type */ +#endif + "\x00\x00\x00\x10" /* enc key length */ + "authenticationkey20benckeyis16_bytes", + .klen = 8 + 20 + 16, + .iv = "iv0123456789abcd", + .input = "\x58\x2a\x11\xc\x86\x8e\x4b\x67" + "\x2d\x16\x26\x1a\xac\x4b\xe2\x1a" + "\xe9\x6a\xcc\x4d\x6f\x79\x8a\x45" + "\x1f\x4e\x27\xf2\xa7\x59\xb4\x5a", + .ilen = 20 + 12, + .assoc = "\x00\x01\x02\x03\x04\x05\x06\x07" + "\x00\x03\x01\x00\x20", + .alen = 13, + .result = "", + .rlen = 0, + }, { +#ifdef __LITTLE_ENDIAN + .key = "\x08\x00" /* rta length */ + "\x01\x00" /* rta type */ +#else + .key = "\x00\x08" /* rta length */ + "\x00\x01" /* rta type */ +#endif + "\x00\x00\x00\x10" /* enc key length */ + "authenticationkey20benckeyis16_bytes", + .klen = 8 + 20 + 16, + .iv = "iv0123456789abcd", + .input = "\x80\x23\x82\x44\x14\x2a\x1d\x94\xc\xc2\x1d\xd" + "\x3a\x32\x89\x4c\x57\x30\xa8\x89\x76\x46\xcc\x90" + "\x1d\x88\xb8\xa6\x1a\x58\xe\x2d\xeb\x2c\xc7\x3a" + "\x52\x4e\xdb\xb3\x1e\x83\x11\xf5\x3c\xce\x6e\x94" + "\xd3\x26\x6a\x9a\xd\xbd\xc7\x98\xb9\xb3\x3a\x51" + "\x1e\x4\x84\x8a\x8f\x54\x9a\x51\x69\x9c\xce\x31" + "\x8d\x5d\x8b\xee\x5f\x70\xc\xc9\xb8\x50\x54\xf8" + "\xb2\x4a\x7a\xcd\xeb\x7a\x82\x81\xc6\x41\xc8\x50" + "\x91\x8d\xc8\xed\xcd\x40\x8f\x55\xd1\xec\xc9\xac" + "\x15\x18\xf9\x20\xa0\xed\x18\xa1\xe3\x56\xe3\x14" + "\xe5\xe8\x66\x63\x20\xed\xe4\x62\x9d\xa3\xa4\x1d" + "\x81\x89\x18\xf2\x36\xae\xc8\x8a\x2b\xbc\xc3\xb8" + "\x80\xf\x97\x21\x36\x39\x8\x84\x23\x18\x9e\x9c" + "\x72\x32\x75\x2d\x2e\xf9\x60\xb\xe8\xcc\xd9\x74" + "\x4\x1b\x8e\x99\xc1\x94\xee\xd0\xac\x4e\xfc\x7e" + "\xf1\x96\xb3\xe7\x14\xb8\xf2\xc\x25\x97\x82\x6b" + "\xbd\x0\x65\xab\x5c\xe3\x16\xfb\x68\xef\xea\x9d" + "\xff\x44\x1d\x2a\x44\xf5\xc8\x56\x77\xb7\xbf\x13" + "\xc8\x54\xdb\x92\xfe\x16\x4c\xbe\x18\xe9\xb\x8d" + "\xb\xd4\x43\x58\x43\xaa\xf4\x3\x80\x97\x62\xd5" + "\xdf\x3c\x28\xaa\xee\x48\x4b\x55\x41\x1b\x31\x2" + "\xbe\xa0\x1c\xbd\xb7\x22\x2a\xe5\x53\x72\x73\x20" + "\x44\x4f\xe6\x1\x2b\x34\x33\x11\x7d\xfb\x10\xc1" + "\x66\x7c\xa6\xf4\x48\x36\x5e\x2\xda\x41\x4b\x3e" + "\xe7\x80\x17\x17\xce\xf1\x3e\x6a\x8e\x26\xf3\xb7" + "\x2b\x85\xd\x31\x8d\xba\x6c\x22\xb4\x28\x55\x7e" + "\x2a\x9e\x26\xf1\x3d\x21\xac\x65", + + .ilen = 285 + 20 + 15, + .assoc = "\x00\x01\x02\x03\x04\x05\x06\x07" + "\x00\x03\x01\x01\x40", + .alen = 13, + .result = "285 bytes plaintext285 bytes plaintext285 bytes" + " plaintext285 bytes plaintext285 bytes plaintext285" + " bytes plaintext285 bytes plaintext285 bytes" + " plaintext285 bytes plaintext285 bytes plaintext285" + " bytes plaintext285 bytes plaintext285 bytes" + " plaintext285 bytes plaintext285 bytes plaintext", + .rlen = 285, + } +}; + +/* * RSA test vectors. Borrowed from openSSL. */ static const struct akcipher_testvec rsa_tv_template[] = { --- /dev/null +++ b/crypto/tls.c @@ -0,0 +1,607 @@ +/* + * Copyright 2013 Freescale Semiconductor, Inc. + * Copyright 2017 NXP Semiconductor, Inc. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct tls_instance_ctx { + struct crypto_ahash_spawn auth; + struct crypto_skcipher_spawn enc; +}; + +struct crypto_tls_ctx { + unsigned int reqoff; + struct crypto_ahash *auth; + struct crypto_skcipher *enc; + struct crypto_sync_skcipher *null; +}; + +struct tls_request_ctx { + /* + * cryptlen holds the payload length in the case of encryption or + * payload_len + icv_len + padding_len in case of decryption + */ + unsigned int cryptlen; + /* working space for partial results */ + struct scatterlist tmp[2]; + struct scatterlist cipher[2]; + struct scatterlist dst[2]; + char tail[]; +}; + +struct async_op { + struct completion completion; + int err; +}; + +static void tls_async_op_done(struct crypto_async_request *req, int err) +{ + struct async_op *areq = req->data; + + if (err == -EINPROGRESS) + return; + + areq->err = err; + complete(&areq->completion); +} + +static int crypto_tls_setkey(struct crypto_aead *tls, const u8 *key, + unsigned int keylen) +{ + struct crypto_tls_ctx *ctx = crypto_aead_ctx(tls); + struct crypto_ahash *auth = ctx->auth; + struct crypto_skcipher *enc = ctx->enc; + struct crypto_authenc_keys keys; + int err = -EINVAL; + + if (crypto_authenc_extractkeys(&keys, key, keylen) != 0) + goto badkey; + + crypto_ahash_clear_flags(auth, CRYPTO_TFM_REQ_MASK); + crypto_ahash_set_flags(auth, crypto_aead_get_flags(tls) & + CRYPTO_TFM_REQ_MASK); + err = crypto_ahash_setkey(auth, keys.authkey, keys.authkeylen); + crypto_aead_set_flags(tls, crypto_ahash_get_flags(auth) & + CRYPTO_TFM_RES_MASK); + + if (err) + goto out; + + crypto_skcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK); + crypto_skcipher_set_flags(enc, crypto_aead_get_flags(tls) & + CRYPTO_TFM_REQ_MASK); + err = crypto_skcipher_setkey(enc, keys.enckey, keys.enckeylen); + crypto_aead_set_flags(tls, crypto_skcipher_get_flags(enc) & + CRYPTO_TFM_RES_MASK); + +out: + return err; + +badkey: + crypto_aead_set_flags(tls, CRYPTO_TFM_RES_BAD_KEY_LEN); + goto out; +} + +/** + * crypto_tls_genicv - Calculate hmac digest for a TLS record + * @hash: (output) buffer to save the digest into + * @src: (input) scatterlist with the assoc and payload data + * @srclen: (input) size of the source buffer (assoclen + cryptlen) + * @req: (input) aead request + **/ +static int crypto_tls_genicv(u8 *hash, struct scatterlist *src, + unsigned int srclen, struct aead_request *req) +{ + struct crypto_aead *tls = crypto_aead_reqtfm(req); + struct crypto_tls_ctx *ctx = crypto_aead_ctx(tls); + struct tls_request_ctx *treq_ctx = aead_request_ctx(req); + struct async_op ahash_op; + struct ahash_request *ahreq = (void *)(treq_ctx->tail + ctx->reqoff); + unsigned int flags = CRYPTO_TFM_REQ_MAY_SLEEP; + int err = -EBADMSG; + + /* Bail out if the request assoc len is 0 */ + if (!req->assoclen) + return err; + + init_completion(&ahash_op.completion); + + /* the hash transform to be executed comes from the original request */ + ahash_request_set_tfm(ahreq, ctx->auth); + /* prepare the hash request with input data and result pointer */ + ahash_request_set_crypt(ahreq, src, hash, srclen); + /* set the notifier for when the async hash function returns */ + ahash_request_set_callback(ahreq, aead_request_flags(req) & flags, + tls_async_op_done, &ahash_op); + + /* Calculate the digest on the given data. The result is put in hash */ + err = crypto_ahash_digest(ahreq); + if (err == -EINPROGRESS) { + err = wait_for_completion_interruptible(&ahash_op.completion); + if (!err) + err = ahash_op.err; + } + + return err; +} + +/** + * crypto_tls_gen_padicv - Calculate and pad hmac digest for a TLS record + * @hash: (output) buffer to save the digest and padding into + * @phashlen: (output) the size of digest + padding + * @req: (input) aead request + **/ +static int crypto_tls_gen_padicv(u8 *hash, unsigned int *phashlen, + struct aead_request *req) +{ + struct crypto_aead *tls = crypto_aead_reqtfm(req); + unsigned int hash_size = crypto_aead_authsize(tls); + unsigned int block_size = crypto_aead_blocksize(tls); + unsigned int srclen = req->cryptlen + hash_size; + unsigned int icvlen = req->cryptlen + req->assoclen; + unsigned int padlen; + int err; + + err = crypto_tls_genicv(hash, req->src, icvlen, req); + if (err) + goto out; + + /* add padding after digest */ + padlen = block_size - (srclen % block_size); + memset(hash + hash_size, padlen - 1, padlen); + + *phashlen = hash_size + padlen; +out: + return err; +} + +static int crypto_tls_copy_data(struct aead_request *req, + struct scatterlist *src, + struct scatterlist *dst, + unsigned int len) +{ + struct crypto_aead *tls = crypto_aead_reqtfm(req); + struct crypto_tls_ctx *ctx = crypto_aead_ctx(tls); + SYNC_SKCIPHER_REQUEST_ON_STACK(skreq, ctx->null); + + skcipher_request_set_sync_tfm(skreq, ctx->null); + skcipher_request_set_callback(skreq, aead_request_flags(req), + NULL, NULL); + skcipher_request_set_crypt(skreq, src, dst, len, NULL); + + return crypto_skcipher_encrypt(skreq); +} + +static int crypto_tls_encrypt(struct aead_request *req) +{ + struct crypto_aead *tls = crypto_aead_reqtfm(req); + struct crypto_tls_ctx *ctx = crypto_aead_ctx(tls); + struct tls_request_ctx *treq_ctx = aead_request_ctx(req); + struct skcipher_request *skreq; + struct scatterlist *cipher = treq_ctx->cipher; + struct scatterlist *tmp = treq_ctx->tmp; + struct scatterlist *sg, *src, *dst; + unsigned int cryptlen, phashlen; + u8 *hash = treq_ctx->tail; + int err; + + /* + * The hash result is saved at the beginning of the tls request ctx + * and is aligned as required by the hash transform. Enough space was + * allocated in crypto_tls_init_tfm to accommodate the difference. The + * requests themselves start later at treq_ctx->tail + ctx->reqoff so + * the result is not overwritten by the second (cipher) request. + */ + hash = (u8 *)ALIGN((unsigned long)hash + + crypto_ahash_alignmask(ctx->auth), + crypto_ahash_alignmask(ctx->auth) + 1); + + /* + * STEP 1: create ICV together with necessary padding + */ + err = crypto_tls_gen_padicv(hash, &phashlen, req); + if (err) + return err; + + /* + * STEP 2: Hash and padding are combined with the payload + * depending on the form it arrives. Scatter tables must have at least + * one page of data before chaining with another table and can't have + * an empty data page. The following code addresses these requirements. + * + * If the payload is empty, only the hash is encrypted, otherwise the + * payload scatterlist is merged with the hash. A special merging case + * is when the payload has only one page of data. In that case the + * payload page is moved to another scatterlist and prepared there for + * encryption. + */ + if (req->cryptlen) { + src = scatterwalk_ffwd(tmp, req->src, req->assoclen); + + sg_init_table(cipher, 2); + sg_set_buf(cipher + 1, hash, phashlen); + + if (sg_is_last(src)) { + sg_set_page(cipher, sg_page(src), req->cryptlen, + src->offset); + src = cipher; + } else { + unsigned int rem_len = req->cryptlen; + + for (sg = src; rem_len > sg->length; sg = sg_next(sg)) + rem_len -= min(rem_len, sg->length); + + sg_set_page(cipher, sg_page(sg), rem_len, sg->offset); + sg_chain(sg, 1, cipher); + } + } else { + sg_init_one(cipher, hash, phashlen); + src = cipher; + } + + /** + * If src != dst copy the associated data from source to destination. + * In both cases fast-forward passed the associated data in the dest. + */ + if (req->src != req->dst) { + err = crypto_tls_copy_data(req, req->src, req->dst, + req->assoclen); + if (err) + return err; + } + dst = scatterwalk_ffwd(treq_ctx->dst, req->dst, req->assoclen); + + /* + * STEP 3: encrypt the frame and return the result + */ + cryptlen = req->cryptlen + phashlen; + + /* + * The hash and the cipher are applied at different times and their + * requests can use the same memory space without interference + */ + skreq = (void *)(treq_ctx->tail + ctx->reqoff); + skcipher_request_set_tfm(skreq, ctx->enc); + skcipher_request_set_crypt(skreq, src, dst, cryptlen, req->iv); + skcipher_request_set_callback(skreq, aead_request_flags(req), + req->base.complete, req->base.data); + /* + * Apply the cipher transform. The result will be in req->dst when the + * asynchronuous call terminates + */ + err = crypto_skcipher_encrypt(skreq); + + return err; +} + +static int crypto_tls_decrypt(struct aead_request *req) +{ + struct crypto_aead *tls = crypto_aead_reqtfm(req); + struct crypto_tls_ctx *ctx = crypto_aead_ctx(tls); + struct tls_request_ctx *treq_ctx = aead_request_ctx(req); + unsigned int cryptlen = req->cryptlen; + unsigned int hash_size = crypto_aead_authsize(tls); + unsigned int block_size = crypto_aead_blocksize(tls); + struct skcipher_request *skreq = (void *)(treq_ctx->tail + ctx->reqoff); + struct scatterlist *tmp = treq_ctx->tmp; + struct scatterlist *src, *dst; + + u8 padding[255]; /* padding can be 0-255 bytes */ + u8 pad_size; + u16 *len_field; + u8 *ihash, *hash = treq_ctx->tail; + + int paderr = 0; + int err = -EINVAL; + int i; + struct async_op ciph_op; + + /* + * Rule out bad packets. The input packet length must be at least one + * byte more than the hash_size + */ + if (cryptlen <= hash_size || cryptlen % block_size) + goto out; + + /* + * Step 1 - Decrypt the source. Fast-forward past the associated data + * to the encrypted data. The result will be overwritten in place so + * that the decrypted data will be adjacent to the associated data. The + * last step (computing the hash) will have it's input data already + * prepared and ready to be accessed at req->src. + */ + src = scatterwalk_ffwd(tmp, req->src, req->assoclen); + dst = src; + + init_completion(&ciph_op.completion); + skcipher_request_set_tfm(skreq, ctx->enc); + skcipher_request_set_callback(skreq, aead_request_flags(req), + tls_async_op_done, &ciph_op); + skcipher_request_set_crypt(skreq, src, dst, cryptlen, req->iv); + err = crypto_skcipher_decrypt(skreq); + if (err == -EINPROGRESS) { + err = wait_for_completion_interruptible(&ciph_op.completion); + if (!err) + err = ciph_op.err; + } + if (err) + goto out; + + /* + * Step 2 - Verify padding + * Retrieve the last byte of the payload; this is the padding size. + */ + cryptlen -= 1; + scatterwalk_map_and_copy(&pad_size, dst, cryptlen, 1, 0); + + /* RFC recommendation for invalid padding size. */ + if (cryptlen < pad_size + hash_size) { + pad_size = 0; + paderr = -EBADMSG; + } + cryptlen -= pad_size; + scatterwalk_map_and_copy(padding, dst, cryptlen, pad_size, 0); + + /* Padding content must be equal with pad_size. We verify it all */ + for (i = 0; i < pad_size; i++) + if (padding[i] != pad_size) + paderr = -EBADMSG; + + /* + * Step 3 - Verify hash + * Align the digest result as required by the hash transform. Enough + * space was allocated in crypto_tls_init_tfm + */ + hash = (u8 *)ALIGN((unsigned long)hash + + crypto_ahash_alignmask(ctx->auth), + crypto_ahash_alignmask(ctx->auth) + 1); + /* + * Two bytes at the end of the associated data make the length field. + * It must be updated with the length of the cleartext message before + * the hash is calculated. + */ + len_field = sg_virt(req->src) + req->assoclen - 2; + cryptlen -= hash_size; + *len_field = htons(cryptlen); + + /* This is the hash from the decrypted packet. Save it for later */ + ihash = hash + hash_size; + scatterwalk_map_and_copy(ihash, dst, cryptlen, hash_size, 0); + + /* Now compute and compare our ICV with the one from the packet */ + err = crypto_tls_genicv(hash, req->src, cryptlen + req->assoclen, req); + if (!err) + err = memcmp(hash, ihash, hash_size) ? -EBADMSG : 0; + + if (req->src != req->dst) { + err = crypto_tls_copy_data(req, req->src, req->dst, cryptlen + + req->assoclen); + if (err) + goto out; + } + + /* return the first found error */ + if (paderr) + err = paderr; + +out: + aead_request_complete(req, err); + return err; +} + +static int crypto_tls_init_tfm(struct crypto_aead *tfm) +{ + struct aead_instance *inst = aead_alg_instance(tfm); + struct tls_instance_ctx *ictx = aead_instance_ctx(inst); + struct crypto_tls_ctx *ctx = crypto_aead_ctx(tfm); + struct crypto_ahash *auth; + struct crypto_skcipher *enc; + struct crypto_sync_skcipher *null; + int err; + + auth = crypto_spawn_ahash(&ictx->auth); + if (IS_ERR(auth)) + return PTR_ERR(auth); + + enc = crypto_spawn_skcipher(&ictx->enc); + err = PTR_ERR(enc); + if (IS_ERR(enc)) + goto err_free_ahash; + + null = crypto_get_default_null_skcipher(); + err = PTR_ERR(null); + if (IS_ERR(null)) + goto err_free_skcipher; + + ctx->auth = auth; + ctx->enc = enc; + ctx->null = null; + + /* + * Allow enough space for two digests. The two digests will be compared + * during the decryption phase. One will come from the decrypted packet + * and the other will be calculated. For encryption, one digest is + * padded (up to a cipher blocksize) and chained with the payload + */ + ctx->reqoff = ALIGN(crypto_ahash_digestsize(auth) + + crypto_ahash_alignmask(auth), + crypto_ahash_alignmask(auth) + 1) + + max(crypto_ahash_digestsize(auth), + crypto_skcipher_blocksize(enc)); + + crypto_aead_set_reqsize(tfm, + sizeof(struct tls_request_ctx) + + ctx->reqoff + + max_t(unsigned int, + crypto_ahash_reqsize(auth) + + sizeof(struct ahash_request), + crypto_skcipher_reqsize(enc) + + sizeof(struct skcipher_request))); + + return 0; + +err_free_skcipher: + crypto_free_skcipher(enc); +err_free_ahash: + crypto_free_ahash(auth); + return err; +} + +static void crypto_tls_exit_tfm(struct crypto_aead *tfm) +{ + struct crypto_tls_ctx *ctx = crypto_aead_ctx(tfm); + + crypto_free_ahash(ctx->auth); + crypto_free_skcipher(ctx->enc); + crypto_put_default_null_skcipher(); +} + +static void crypto_tls_free(struct aead_instance *inst) +{ + struct tls_instance_ctx *ctx = aead_instance_ctx(inst); + + crypto_drop_skcipher(&ctx->enc); + crypto_drop_ahash(&ctx->auth); + kfree(inst); +} + +static int crypto_tls_create(struct crypto_template *tmpl, struct rtattr **tb) +{ + struct crypto_attr_type *algt; + struct aead_instance *inst; + struct hash_alg_common *auth; + struct crypto_alg *auth_base; + struct skcipher_alg *enc; + struct tls_instance_ctx *ctx; + const char *enc_name; + int err; + + algt = crypto_get_attr_type(tb); + if (IS_ERR(algt)) + return PTR_ERR(algt); + + if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask) + return -EINVAL; + + auth = ahash_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH, + CRYPTO_ALG_TYPE_AHASH_MASK | + crypto_requires_sync(algt->type, algt->mask)); + if (IS_ERR(auth)) + return PTR_ERR(auth); + + auth_base = &auth->base; + + enc_name = crypto_attr_alg_name(tb[2]); + err = PTR_ERR(enc_name); + if (IS_ERR(enc_name)) + goto out_put_auth; + + inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL); + err = -ENOMEM; + if (!inst) + goto out_put_auth; + + ctx = aead_instance_ctx(inst); + + err = crypto_init_ahash_spawn(&ctx->auth, auth, + aead_crypto_instance(inst)); + if (err) + goto err_free_inst; + + crypto_set_skcipher_spawn(&ctx->enc, aead_crypto_instance(inst)); + err = crypto_grab_skcipher(&ctx->enc, enc_name, 0, + crypto_requires_sync(algt->type, + algt->mask)); + if (err) + goto err_drop_auth; + + enc = crypto_spawn_skcipher_alg(&ctx->enc); + + err = -ENAMETOOLONG; + if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, + "tls10(%s,%s)", auth_base->cra_name, + enc->base.cra_name) >= CRYPTO_MAX_ALG_NAME) + goto err_drop_enc; + + if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, + "tls10(%s,%s)", auth_base->cra_driver_name, + enc->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME) + goto err_drop_enc; + + inst->alg.base.cra_flags = (auth_base->cra_flags | + enc->base.cra_flags) & CRYPTO_ALG_ASYNC; + inst->alg.base.cra_priority = enc->base.cra_priority * 10 + + auth_base->cra_priority; + inst->alg.base.cra_blocksize = enc->base.cra_blocksize; + inst->alg.base.cra_alignmask = auth_base->cra_alignmask | + enc->base.cra_alignmask; + inst->alg.base.cra_ctxsize = sizeof(struct crypto_tls_ctx); + + inst->alg.ivsize = crypto_skcipher_alg_ivsize(enc); + inst->alg.chunksize = crypto_skcipher_alg_chunksize(enc); + inst->alg.maxauthsize = auth->digestsize; + + inst->alg.init = crypto_tls_init_tfm; + inst->alg.exit = crypto_tls_exit_tfm; + + inst->alg.setkey = crypto_tls_setkey; + inst->alg.encrypt = crypto_tls_encrypt; + inst->alg.decrypt = crypto_tls_decrypt; + + inst->free = crypto_tls_free; + + err = aead_register_instance(tmpl, inst); + if (err) + goto err_drop_enc; + +out: + crypto_mod_put(auth_base); + return err; + +err_drop_enc: + crypto_drop_skcipher(&ctx->enc); +err_drop_auth: + crypto_drop_ahash(&ctx->auth); +err_free_inst: + kfree(inst); +out_put_auth: + goto out; +} + +static struct crypto_template crypto_tls_tmpl = { + .name = "tls10", + .create = crypto_tls_create, + .module = THIS_MODULE, +}; + +static int __init crypto_tls_module_init(void) +{ + return crypto_register_template(&crypto_tls_tmpl); +} + +static void __exit crypto_tls_module_exit(void) +{ + crypto_unregister_template(&crypto_tls_tmpl); +} + +module_init(crypto_tls_module_init); +module_exit(crypto_tls_module_exit); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("TLS 1.0 record encryption");