| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Harald Freudenberger | 3992 | 88.89% | 6 | 28.57% |
| Jan Glauber | 462 | 10.29% | 2 | 9.52% |
| Martin Schwidefsky | 12 | 0.27% | 4 | 19.05% |
| Dan Carpenter | 6 | 0.13% | 1 | 4.76% |
| Hendrik Brueckner | 6 | 0.13% | 1 | 4.76% |
| Ingo Molnar | 3 | 0.07% | 1 | 4.76% |
| Tejun Heo | 3 | 0.07% | 1 | 4.76% |
| Arnd Bergmann | 2 | 0.04% | 1 | 4.76% |
| David Hildenbrand | 2 | 0.04% | 1 | 4.76% |
| Linus Torvalds | 1 | 0.02% | 1 | 4.76% |
| Greg Kroah-Hartman | 1 | 0.02% | 1 | 4.76% |
| Colin Ian King | 1 | 0.02% | 1 | 4.76% |
| Total | 4491 | 21 |
// SPDX-License-Identifier: GPL-2.0 /* * Copyright IBM Corp. 2006, 2015 * Author(s): Jan Glauber <jan.glauber@de.ibm.com> * Harald Freudenberger <freude@de.ibm.com> * Driver for the s390 pseudo random number generator */ #define KMSG_COMPONENT "prng" #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt #include <linux/fs.h> #include <linux/fips.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/device.h> #include <linux/miscdevice.h> #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/mutex.h> #include <linux/cpufeature.h> #include <linux/random.h> #include <linux/slab.h> #include <linux/sched/signal.h> #include <asm/debug.h> #include <linux/uaccess.h> #include <asm/timex.h> #include <asm/cpacf.h> MODULE_LICENSE("GPL"); MODULE_AUTHOR("IBM Corporation"); MODULE_DESCRIPTION("s390 PRNG interface"); #define PRNG_MODE_AUTO 0 #define PRNG_MODE_TDES 1 #define PRNG_MODE_SHA512 2 static unsigned int prng_mode = PRNG_MODE_AUTO; module_param_named(mode, prng_mode, int, 0); MODULE_PARM_DESC(prng_mode, "PRNG mode: 0 - auto, 1 - TDES, 2 - SHA512"); #define PRNG_CHUNKSIZE_TDES_MIN 8 #define PRNG_CHUNKSIZE_TDES_MAX (64*1024) #define PRNG_CHUNKSIZE_SHA512_MIN 64 #define PRNG_CHUNKSIZE_SHA512_MAX (64*1024) static unsigned int prng_chunk_size = 256; module_param_named(chunksize, prng_chunk_size, int, 0); MODULE_PARM_DESC(prng_chunk_size, "PRNG read chunk size in bytes"); #define PRNG_RESEED_LIMIT_TDES 4096 #define PRNG_RESEED_LIMIT_TDES_LOWER 4096 #define PRNG_RESEED_LIMIT_SHA512 100000 #define PRNG_RESEED_LIMIT_SHA512_LOWER 10000 static unsigned int prng_reseed_limit; module_param_named(reseed_limit, prng_reseed_limit, int, 0); MODULE_PARM_DESC(prng_reseed_limit, "PRNG reseed limit"); static bool trng_available; /* * Any one who considers arithmetical methods of producing random digits is, * of course, in a state of sin. -- John von Neumann */ static int prng_errorflag; #define PRNG_GEN_ENTROPY_FAILED 1 #define PRNG_SELFTEST_FAILED 2 #define PRNG_INSTANTIATE_FAILED 3 #define PRNG_SEED_FAILED 4 #define PRNG_RESEED_FAILED 5 #define PRNG_GEN_FAILED 6 struct prng_ws_s { u8 parm_block[32]; u32 reseed_counter; u64 byte_counter; }; struct prno_ws_s { u32 res; u32 reseed_counter; u64 stream_bytes; u8 V[112]; u8 C[112]; }; struct prng_data_s { struct mutex mutex; union { struct prng_ws_s prngws; struct prno_ws_s prnows; }; u8 *buf; u32 rest; u8 *prev; }; static struct prng_data_s *prng_data; /* initial parameter block for tdes mode, copied from libica */ static const u8 initial_parm_block[32] __initconst = { 0x0F, 0x2B, 0x8E, 0x63, 0x8C, 0x8E, 0xD2, 0x52, 0x64, 0xB7, 0xA0, 0x7B, 0x75, 0x28, 0xB8, 0xF4, 0x75, 0x5F, 0xD2, 0xA6, 0x8D, 0x97, 0x11, 0xFF, 0x49, 0xD8, 0x23, 0xF3, 0x7E, 0x21, 0xEC, 0xA0 }; /*** helper functions ***/ /* * generate_entropy: * This function fills a given buffer with random bytes. The entropy within * the random bytes given back is assumed to have at least 50% - meaning * a 64 bytes buffer has at least 64 * 8 / 2 = 256 bits of entropy. * Within the function the entropy generation is done in junks of 64 bytes. * So the caller should also ask for buffer fill in multiples of 64 bytes. * The generation of the entropy is based on the assumption that every stckf() * invocation produces 0.5 bits of entropy. To accumulate 256 bits of entropy * at least 512 stckf() values are needed. The entropy relevant part of the * stckf value is bit 51 (counting starts at the left with bit nr 0) so * here we use the lower 4 bytes and exor the values into 2k of bufferspace. * To be on the save side, if there is ever a problem with stckf() the * other half of the page buffer is filled with bytes from urandom via * get_random_bytes(), so this function consumes 2k of urandom for each * requested 64 bytes output data. Finally the buffer page is condensed into * a 64 byte value by hashing with a SHA512 hash. */ static int generate_entropy(u8 *ebuf, size_t nbytes) { int n, ret = 0; u8 *pg, pblock[80] = { /* 8 x 64 bit init values */ 0x6A, 0x09, 0xE6, 0x67, 0xF3, 0xBC, 0xC9, 0x08, 0xBB, 0x67, 0xAE, 0x85, 0x84, 0xCA, 0xA7, 0x3B, 0x3C, 0x6E, 0xF3, 0x72, 0xFE, 0x94, 0xF8, 0x2B, 0xA5, 0x4F, 0xF5, 0x3A, 0x5F, 0x1D, 0x36, 0xF1, 0x51, 0x0E, 0x52, 0x7F, 0xAD, 0xE6, 0x82, 0xD1, 0x9B, 0x05, 0x68, 0x8C, 0x2B, 0x3E, 0x6C, 0x1F, 0x1F, 0x83, 0xD9, 0xAB, 0xFB, 0x41, 0xBD, 0x6B, 0x5B, 0xE0, 0xCD, 0x19, 0x13, 0x7E, 0x21, 0x79, /* 128 bit counter total message bit length */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80, 0x00 }; /* allocate one page stckf buffer */ pg = (u8 *) __get_free_page(GFP_KERNEL); if (!pg) { prng_errorflag = PRNG_GEN_ENTROPY_FAILED; return -ENOMEM; } /* fill the ebuf in chunks of 64 byte each */ while (nbytes) { /* fill lower 2k with urandom bytes */ get_random_bytes(pg, PAGE_SIZE / 2); /* exor upper 2k with 512 stckf values, offset 4 bytes each */ for (n = 0; n < 512; n++) { int offset = (PAGE_SIZE / 2) + (n * 4) - 4; u64 *p = (u64 *)(pg + offset); *p ^= get_tod_clock_fast(); } /* hash over the filled page */ cpacf_klmd(CPACF_KLMD_SHA_512, pblock, pg, PAGE_SIZE); n = (nbytes < 64) ? nbytes : 64; memcpy(ebuf, pblock, n); ret += n; ebuf += n; nbytes -= n; } memzero_explicit(pblock, sizeof(pblock)); memzero_explicit(pg, PAGE_SIZE); free_page((unsigned long)pg); return ret; } /*** tdes functions ***/ static void prng_tdes_add_entropy(void) { __u64 entropy[4]; unsigned int i; for (i = 0; i < 16; i++) { cpacf_kmc(CPACF_KMC_PRNG, prng_data->prngws.parm_block, (char *) entropy, (char *) entropy, sizeof(entropy)); memcpy(prng_data->prngws.parm_block, entropy, sizeof(entropy)); } } static void prng_tdes_seed(int nbytes) { char buf[16]; int i = 0; BUG_ON(nbytes > sizeof(buf)); get_random_bytes(buf, nbytes); /* Add the entropy */ while (nbytes >= 8) { *((__u64 *)prng_data->prngws.parm_block) ^= *((__u64 *)(buf+i)); prng_tdes_add_entropy(); i += 8; nbytes -= 8; } prng_tdes_add_entropy(); prng_data->prngws.reseed_counter = 0; } static int __init prng_tdes_instantiate(void) { int datalen; pr_debug("prng runs in TDES mode with " "chunksize=%d and reseed_limit=%u\n", prng_chunk_size, prng_reseed_limit); /* memory allocation, prng_data struct init, mutex init */ datalen = sizeof(struct prng_data_s) + prng_chunk_size; prng_data = kzalloc(datalen, GFP_KERNEL); if (!prng_data) { prng_errorflag = PRNG_INSTANTIATE_FAILED; return -ENOMEM; } mutex_init(&prng_data->mutex); prng_data->buf = ((u8 *)prng_data) + sizeof(struct prng_data_s); memcpy(prng_data->prngws.parm_block, initial_parm_block, 32); /* initialize the PRNG, add 128 bits of entropy */ prng_tdes_seed(16); return 0; } static void prng_tdes_deinstantiate(void) { pr_debug("The prng module stopped " "after running in triple DES mode\n"); kzfree(prng_data); } /*** sha512 functions ***/ static int __init prng_sha512_selftest(void) { /* NIST DRBG testvector for Hash Drbg, Sha-512, Count #0 */ static const u8 seed[] __initconst = { 0x6b, 0x50, 0xa7, 0xd8, 0xf8, 0xa5, 0x5d, 0x7a, 0x3d, 0xf8, 0xbb, 0x40, 0xbc, 0xc3, 0xb7, 0x22, 0xd8, 0x70, 0x8d, 0xe6, 0x7f, 0xda, 0x01, 0x0b, 0x03, 0xc4, 0xc8, 0x4d, 0x72, 0x09, 0x6f, 0x8c, 0x3e, 0xc6, 0x49, 0xcc, 0x62, 0x56, 0xd9, 0xfa, 0x31, 0xdb, 0x7a, 0x29, 0x04, 0xaa, 0xf0, 0x25 }; static const u8 V0[] __initconst = { 0x00, 0xad, 0xe3, 0x6f, 0x9a, 0x01, 0xc7, 0x76, 0x61, 0x34, 0x35, 0xf5, 0x4e, 0x24, 0x74, 0x22, 0x21, 0x9a, 0x29, 0x89, 0xc7, 0x93, 0x2e, 0x60, 0x1e, 0xe8, 0x14, 0x24, 0x8d, 0xd5, 0x03, 0xf1, 0x65, 0x5d, 0x08, 0x22, 0x72, 0xd5, 0xad, 0x95, 0xe1, 0x23, 0x1e, 0x8a, 0xa7, 0x13, 0xd9, 0x2b, 0x5e, 0xbc, 0xbb, 0x80, 0xab, 0x8d, 0xe5, 0x79, 0xab, 0x5b, 0x47, 0x4e, 0xdd, 0xee, 0x6b, 0x03, 0x8f, 0x0f, 0x5c, 0x5e, 0xa9, 0x1a, 0x83, 0xdd, 0xd3, 0x88, 0xb2, 0x75, 0x4b, 0xce, 0x83, 0x36, 0x57, 0x4b, 0xf1, 0x5c, 0xca, 0x7e, 0x09, 0xc0, 0xd3, 0x89, 0xc6, 0xe0, 0xda, 0xc4, 0x81, 0x7e, 0x5b, 0xf9, 0xe1, 0x01, 0xc1, 0x92, 0x05, 0xea, 0xf5, 0x2f, 0xc6, 0xc6, 0xc7, 0x8f, 0xbc, 0xf4 }; static const u8 C0[] __initconst = { 0x00, 0xf4, 0xa3, 0xe5, 0xa0, 0x72, 0x63, 0x95, 0xc6, 0x4f, 0x48, 0xd0, 0x8b, 0x5b, 0x5f, 0x8e, 0x6b, 0x96, 0x1f, 0x16, 0xed, 0xbc, 0x66, 0x94, 0x45, 0x31, 0xd7, 0x47, 0x73, 0x22, 0xa5, 0x86, 0xce, 0xc0, 0x4c, 0xac, 0x63, 0xb8, 0x39, 0x50, 0xbf, 0xe6, 0x59, 0x6c, 0x38, 0x58, 0x99, 0x1f, 0x27, 0xa7, 0x9d, 0x71, 0x2a, 0xb3, 0x7b, 0xf9, 0xfb, 0x17, 0x86, 0xaa, 0x99, 0x81, 0xaa, 0x43, 0xe4, 0x37, 0xd3, 0x1e, 0x6e, 0xe5, 0xe6, 0xee, 0xc2, 0xed, 0x95, 0x4f, 0x53, 0x0e, 0x46, 0x8a, 0xcc, 0x45, 0xa5, 0xdb, 0x69, 0x0d, 0x81, 0xc9, 0x32, 0x92, 0xbc, 0x8f, 0x33, 0xe6, 0xf6, 0x09, 0x7c, 0x8e, 0x05, 0x19, 0x0d, 0xf1, 0xb6, 0xcc, 0xf3, 0x02, 0x21, 0x90, 0x25, 0xec, 0xed, 0x0e }; static const u8 random[] __initconst = { 0x95, 0xb7, 0xf1, 0x7e, 0x98, 0x02, 0xd3, 0x57, 0x73, 0x92, 0xc6, 0xa9, 0xc0, 0x80, 0x83, 0xb6, 0x7d, 0xd1, 0x29, 0x22, 0x65, 0xb5, 0xf4, 0x2d, 0x23, 0x7f, 0x1c, 0x55, 0xbb, 0x9b, 0x10, 0xbf, 0xcf, 0xd8, 0x2c, 0x77, 0xa3, 0x78, 0xb8, 0x26, 0x6a, 0x00, 0x99, 0x14, 0x3b, 0x3c, 0x2d, 0x64, 0x61, 0x1e, 0xee, 0xb6, 0x9a, 0xcd, 0xc0, 0x55, 0x95, 0x7c, 0x13, 0x9e, 0x8b, 0x19, 0x0c, 0x7a, 0x06, 0x95, 0x5f, 0x2c, 0x79, 0x7c, 0x27, 0x78, 0xde, 0x94, 0x03, 0x96, 0xa5, 0x01, 0xf4, 0x0e, 0x91, 0x39, 0x6a, 0xcf, 0x8d, 0x7e, 0x45, 0xeb, 0xdb, 0xb5, 0x3b, 0xbf, 0x8c, 0x97, 0x52, 0x30, 0xd2, 0xf0, 0xff, 0x91, 0x06, 0xc7, 0x61, 0x19, 0xae, 0x49, 0x8e, 0x7f, 0xbc, 0x03, 0xd9, 0x0f, 0x8e, 0x4c, 0x51, 0x62, 0x7a, 0xed, 0x5c, 0x8d, 0x42, 0x63, 0xd5, 0xd2, 0xb9, 0x78, 0x87, 0x3a, 0x0d, 0xe5, 0x96, 0xee, 0x6d, 0xc7, 0xf7, 0xc2, 0x9e, 0x37, 0xee, 0xe8, 0xb3, 0x4c, 0x90, 0xdd, 0x1c, 0xf6, 0xa9, 0xdd, 0xb2, 0x2b, 0x4c, 0xbd, 0x08, 0x6b, 0x14, 0xb3, 0x5d, 0xe9, 0x3d, 0xa2, 0xd5, 0xcb, 0x18, 0x06, 0x69, 0x8c, 0xbd, 0x7b, 0xbb, 0x67, 0xbf, 0xe3, 0xd3, 0x1f, 0xd2, 0xd1, 0xdb, 0xd2, 0xa1, 0xe0, 0x58, 0xa3, 0xeb, 0x99, 0xd7, 0xe5, 0x1f, 0x1a, 0x93, 0x8e, 0xed, 0x5e, 0x1c, 0x1d, 0xe2, 0x3a, 0x6b, 0x43, 0x45, 0xd3, 0x19, 0x14, 0x09, 0xf9, 0x2f, 0x39, 0xb3, 0x67, 0x0d, 0x8d, 0xbf, 0xb6, 0x35, 0xd8, 0xe6, 0xa3, 0x69, 0x32, 0xd8, 0x10, 0x33, 0xd1, 0x44, 0x8d, 0x63, 0xb4, 0x03, 0xdd, 0xf8, 0x8e, 0x12, 0x1b, 0x6e, 0x81, 0x9a, 0xc3, 0x81, 0x22, 0x6c, 0x13, 0x21, 0xe4, 0xb0, 0x86, 0x44, 0xf6, 0x72, 0x7c, 0x36, 0x8c, 0x5a, 0x9f, 0x7a, 0x4b, 0x3e, 0xe2 }; u8 buf[sizeof(random)]; struct prno_ws_s ws; memset(&ws, 0, sizeof(ws)); /* initial seed */ cpacf_prno(CPACF_PRNO_SHA512_DRNG_SEED, &ws, NULL, 0, seed, sizeof(seed)); /* check working states V and C */ if (memcmp(ws.V, V0, sizeof(V0)) != 0 || memcmp(ws.C, C0, sizeof(C0)) != 0) { pr_err("The prng self test state test " "for the SHA-512 mode failed\n"); prng_errorflag = PRNG_SELFTEST_FAILED; return -EIO; } /* generate random bytes */ cpacf_prno(CPACF_PRNO_SHA512_DRNG_GEN, &ws, buf, sizeof(buf), NULL, 0); cpacf_prno(CPACF_PRNO_SHA512_DRNG_GEN, &ws, buf, sizeof(buf), NULL, 0); /* check against expected data */ if (memcmp(buf, random, sizeof(random)) != 0) { pr_err("The prng self test data test " "for the SHA-512 mode failed\n"); prng_errorflag = PRNG_SELFTEST_FAILED; return -EIO; } return 0; } static int __init prng_sha512_instantiate(void) { int ret, datalen, seedlen; u8 seed[128 + 16]; pr_debug("prng runs in SHA-512 mode " "with chunksize=%d and reseed_limit=%u\n", prng_chunk_size, prng_reseed_limit); /* memory allocation, prng_data struct init, mutex init */ datalen = sizeof(struct prng_data_s) + prng_chunk_size; if (fips_enabled) datalen += prng_chunk_size; prng_data = kzalloc(datalen, GFP_KERNEL); if (!prng_data) { prng_errorflag = PRNG_INSTANTIATE_FAILED; return -ENOMEM; } mutex_init(&prng_data->mutex); prng_data->buf = ((u8 *)prng_data) + sizeof(struct prng_data_s); /* selftest */ ret = prng_sha512_selftest(); if (ret) goto outfree; /* generate initial seed, we need at least 256 + 128 bits entropy. */ if (trng_available) { /* * Trng available, so use it. The trng works in chunks of * 32 bytes and produces 100% entropy. So we pull 64 bytes * which gives us 512 bits entropy. */ seedlen = 2 * 32; cpacf_trng(NULL, 0, seed, seedlen); } else { /* * No trng available, so use the generate_entropy() function. * This function works in 64 byte junks and produces * 50% entropy. So we pull 2*64 bytes which gives us 512 bits * of entropy. */ seedlen = 2 * 64; ret = generate_entropy(seed, seedlen); if (ret != seedlen) goto outfree; } /* append the seed by 16 bytes of unique nonce */ get_tod_clock_ext(seed + seedlen); seedlen += 16; /* now initial seed of the prno drng */ cpacf_prno(CPACF_PRNO_SHA512_DRNG_SEED, &prng_data->prnows, NULL, 0, seed, seedlen); memzero_explicit(seed, sizeof(seed)); /* if fips mode is enabled, generate a first block of random bytes for the FIPS 140-2 Conditional Self Test */ if (fips_enabled) { prng_data->prev = prng_data->buf + prng_chunk_size; cpacf_prno(CPACF_PRNO_SHA512_DRNG_GEN, &prng_data->prnows, prng_data->prev, prng_chunk_size, NULL, 0); } return 0; outfree: kfree(prng_data); return ret; } static void prng_sha512_deinstantiate(void) { pr_debug("The prng module stopped after running in SHA-512 mode\n"); kzfree(prng_data); } static int prng_sha512_reseed(void) { int ret, seedlen; u8 seed[64]; /* We need at least 256 bits of fresh entropy for reseeding */ if (trng_available) { /* trng produces 256 bits entropy in 32 bytes */ seedlen = 32; cpacf_trng(NULL, 0, seed, seedlen); } else { /* generate_entropy() produces 256 bits entropy in 64 bytes */ seedlen = 64; ret = generate_entropy(seed, seedlen); if (ret != sizeof(seed)) return ret; } /* do a reseed of the prno drng with this bytestring */ cpacf_prno(CPACF_PRNO_SHA512_DRNG_SEED, &prng_data->prnows, NULL, 0, seed, seedlen); memzero_explicit(seed, sizeof(seed)); return 0; } static int prng_sha512_generate(u8 *buf, size_t nbytes) { int ret; /* reseed needed ? */ if (prng_data->prnows.reseed_counter > prng_reseed_limit) { ret = prng_sha512_reseed(); if (ret) return ret; } /* PRNO generate */ cpacf_prno(CPACF_PRNO_SHA512_DRNG_GEN, &prng_data->prnows, buf, nbytes, NULL, 0); /* FIPS 140-2 Conditional Self Test */ if (fips_enabled) { if (!memcmp(prng_data->prev, buf, nbytes)) { prng_errorflag = PRNG_GEN_FAILED; return -EILSEQ; } memcpy(prng_data->prev, buf, nbytes); } return nbytes; } /*** file io functions ***/ static int prng_open(struct inode *inode, struct file *file) { return nonseekable_open(inode, file); } static ssize_t prng_tdes_read(struct file *file, char __user *ubuf, size_t nbytes, loff_t *ppos) { int chunk, n, ret = 0; /* lock prng_data struct */ if (mutex_lock_interruptible(&prng_data->mutex)) return -ERESTARTSYS; while (nbytes) { if (need_resched()) { if (signal_pending(current)) { if (ret == 0) ret = -ERESTARTSYS; break; } /* give mutex free before calling schedule() */ mutex_unlock(&prng_data->mutex); schedule(); /* occopy mutex again */ if (mutex_lock_interruptible(&prng_data->mutex)) { if (ret == 0) ret = -ERESTARTSYS; return ret; } } /* * we lose some random bytes if an attacker issues * reads < 8 bytes, but we don't care */ chunk = min_t(int, nbytes, prng_chunk_size); /* PRNG only likes multiples of 8 bytes */ n = (chunk + 7) & -8; if (prng_data->prngws.reseed_counter > prng_reseed_limit) prng_tdes_seed(8); /* if the CPU supports PRNG stckf is present too */ *((unsigned long long *)prng_data->buf) = get_tod_clock_fast(); /* * Beside the STCKF the input for the TDES-EDE is the output * of the last operation. We differ here from X9.17 since we * only store one timestamp into the buffer. Padding the whole * buffer with timestamps does not improve security, since * successive stckf have nearly constant offsets. * If an attacker knows the first timestamp it would be * trivial to guess the additional values. One timestamp * is therefore enough and still guarantees unique input values. * * Note: you can still get strict X9.17 conformity by setting * prng_chunk_size to 8 bytes. */ cpacf_kmc(CPACF_KMC_PRNG, prng_data->prngws.parm_block, prng_data->buf, prng_data->buf, n); prng_data->prngws.byte_counter += n; prng_data->prngws.reseed_counter += n; if (copy_to_user(ubuf, prng_data->buf, chunk)) { ret = -EFAULT; break; } nbytes -= chunk; ret += chunk; ubuf += chunk; } /* unlock prng_data struct */ mutex_unlock(&prng_data->mutex); return ret; } static ssize_t prng_sha512_read(struct file *file, char __user *ubuf, size_t nbytes, loff_t *ppos) { int n, ret = 0; u8 *p; /* if errorflag is set do nothing and return 'broken pipe' */ if (prng_errorflag) return -EPIPE; /* lock prng_data struct */ if (mutex_lock_interruptible(&prng_data->mutex)) return -ERESTARTSYS; while (nbytes) { if (need_resched()) { if (signal_pending(current)) { if (ret == 0) ret = -ERESTARTSYS; break; } /* give mutex free before calling schedule() */ mutex_unlock(&prng_data->mutex); schedule(); /* occopy mutex again */ if (mutex_lock_interruptible(&prng_data->mutex)) { if (ret == 0) ret = -ERESTARTSYS; return ret; } } if (prng_data->rest) { /* push left over random bytes from the previous read */ p = prng_data->buf + prng_chunk_size - prng_data->rest; n = (nbytes < prng_data->rest) ? nbytes : prng_data->rest; prng_data->rest -= n; } else { /* generate one chunk of random bytes into read buf */ p = prng_data->buf; n = prng_sha512_generate(p, prng_chunk_size); if (n < 0) { ret = n; break; } if (nbytes < prng_chunk_size) { n = nbytes; prng_data->rest = prng_chunk_size - n; } else { n = prng_chunk_size; prng_data->rest = 0; } } if (copy_to_user(ubuf, p, n)) { ret = -EFAULT; break; } memzero_explicit(p, n); ubuf += n; nbytes -= n; ret += n; } /* unlock prng_data struct */ mutex_unlock(&prng_data->mutex); return ret; } /*** sysfs stuff ***/ static const struct file_operations prng_sha512_fops = { .owner = THIS_MODULE, .open = &prng_open, .release = NULL, .read = &prng_sha512_read, .llseek = noop_llseek, }; static const struct file_operations prng_tdes_fops = { .owner = THIS_MODULE, .open = &prng_open, .release = NULL, .read = &prng_tdes_read, .llseek = noop_llseek, }; static struct miscdevice prng_sha512_dev = { .name = "prandom", .minor = MISC_DYNAMIC_MINOR, .mode = 0644, .fops = &prng_sha512_fops, }; static struct miscdevice prng_tdes_dev = { .name = "prandom", .minor = MISC_DYNAMIC_MINOR, .mode = 0644, .fops = &prng_tdes_fops, }; /* chunksize attribute (ro) */ static ssize_t prng_chunksize_show(struct device *dev, struct device_attribute *attr, char *buf) { return snprintf(buf, PAGE_SIZE, "%u\n", prng_chunk_size); } static DEVICE_ATTR(chunksize, 0444, prng_chunksize_show, NULL); /* counter attribute (ro) */ static ssize_t prng_counter_show(struct device *dev, struct device_attribute *attr, char *buf) { u64 counter; if (mutex_lock_interruptible(&prng_data->mutex)) return -ERESTARTSYS; if (prng_mode == PRNG_MODE_SHA512) counter = prng_data->prnows.stream_bytes; else counter = prng_data->prngws.byte_counter; mutex_unlock(&prng_data->mutex); return snprintf(buf, PAGE_SIZE, "%llu\n", counter); } static DEVICE_ATTR(byte_counter, 0444, prng_counter_show, NULL); /* errorflag attribute (ro) */ static ssize_t prng_errorflag_show(struct device *dev, struct device_attribute *attr, char *buf) { return snprintf(buf, PAGE_SIZE, "%d\n", prng_errorflag); } static DEVICE_ATTR(errorflag, 0444, prng_errorflag_show, NULL); /* mode attribute (ro) */ static ssize_t prng_mode_show(struct device *dev, struct device_attribute *attr, char *buf) { if (prng_mode == PRNG_MODE_TDES) return snprintf(buf, PAGE_SIZE, "TDES\n"); else return snprintf(buf, PAGE_SIZE, "SHA512\n"); } static DEVICE_ATTR(mode, 0444, prng_mode_show, NULL); /* reseed attribute (w) */ static ssize_t prng_reseed_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { if (mutex_lock_interruptible(&prng_data->mutex)) return -ERESTARTSYS; prng_sha512_reseed(); mutex_unlock(&prng_data->mutex); return count; } static DEVICE_ATTR(reseed, 0200, NULL, prng_reseed_store); /* reseed limit attribute (rw) */ static ssize_t prng_reseed_limit_show(struct device *dev, struct device_attribute *attr, char *buf) { return snprintf(buf, PAGE_SIZE, "%u\n", prng_reseed_limit); } static ssize_t prng_reseed_limit_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { unsigned limit; if (sscanf(buf, "%u\n", &limit) != 1) return -EINVAL; if (prng_mode == PRNG_MODE_SHA512) { if (limit < PRNG_RESEED_LIMIT_SHA512_LOWER) return -EINVAL; } else { if (limit < PRNG_RESEED_LIMIT_TDES_LOWER) return -EINVAL; } prng_reseed_limit = limit; return count; } static DEVICE_ATTR(reseed_limit, 0644, prng_reseed_limit_show, prng_reseed_limit_store); /* strength attribute (ro) */ static ssize_t prng_strength_show(struct device *dev, struct device_attribute *attr, char *buf) { return snprintf(buf, PAGE_SIZE, "256\n"); } static DEVICE_ATTR(strength, 0444, prng_strength_show, NULL); static struct attribute *prng_sha512_dev_attrs[] = { &dev_attr_errorflag.attr, &dev_attr_chunksize.attr, &dev_attr_byte_counter.attr, &dev_attr_mode.attr, &dev_attr_reseed.attr, &dev_attr_reseed_limit.attr, &dev_attr_strength.attr, NULL }; static struct attribute *prng_tdes_dev_attrs[] = { &dev_attr_chunksize.attr, &dev_attr_byte_counter.attr, &dev_attr_mode.attr, NULL }; static struct attribute_group prng_sha512_dev_attr_group = { .attrs = prng_sha512_dev_attrs }; static struct attribute_group prng_tdes_dev_attr_group = { .attrs = prng_tdes_dev_attrs }; /*** module init and exit ***/ static int __init prng_init(void) { int ret; /* check if the CPU has a PRNG */ if (!cpacf_query_func(CPACF_KMC, CPACF_KMC_PRNG)) return -ENODEV; /* check if TRNG subfunction is available */ if (cpacf_query_func(CPACF_PRNO, CPACF_PRNO_TRNG)) trng_available = true; /* choose prng mode */ if (prng_mode != PRNG_MODE_TDES) { /* check for MSA5 support for PRNO operations */ if (!cpacf_query_func(CPACF_PRNO, CPACF_PRNO_SHA512_DRNG_GEN)) { if (prng_mode == PRNG_MODE_SHA512) { pr_err("The prng module cannot " "start in SHA-512 mode\n"); return -ENODEV; } prng_mode = PRNG_MODE_TDES; } else prng_mode = PRNG_MODE_SHA512; } if (prng_mode == PRNG_MODE_SHA512) { /* SHA512 mode */ if (prng_chunk_size < PRNG_CHUNKSIZE_SHA512_MIN || prng_chunk_size > PRNG_CHUNKSIZE_SHA512_MAX) return -EINVAL; prng_chunk_size = (prng_chunk_size + 0x3f) & ~0x3f; if (prng_reseed_limit == 0) prng_reseed_limit = PRNG_RESEED_LIMIT_SHA512; else if (prng_reseed_limit < PRNG_RESEED_LIMIT_SHA512_LOWER) return -EINVAL; ret = prng_sha512_instantiate(); if (ret) goto out; ret = misc_register(&prng_sha512_dev); if (ret) { prng_sha512_deinstantiate(); goto out; } ret = sysfs_create_group(&prng_sha512_dev.this_device->kobj, &prng_sha512_dev_attr_group); if (ret) { misc_deregister(&prng_sha512_dev); prng_sha512_deinstantiate(); goto out; } } else { /* TDES mode */ if (prng_chunk_size < PRNG_CHUNKSIZE_TDES_MIN || prng_chunk_size > PRNG_CHUNKSIZE_TDES_MAX) return -EINVAL; prng_chunk_size = (prng_chunk_size + 0x07) & ~0x07; if (prng_reseed_limit == 0) prng_reseed_limit = PRNG_RESEED_LIMIT_TDES; else if (prng_reseed_limit < PRNG_RESEED_LIMIT_TDES_LOWER) return -EINVAL; ret = prng_tdes_instantiate(); if (ret) goto out; ret = misc_register(&prng_tdes_dev); if (ret) { prng_tdes_deinstantiate(); goto out; } ret = sysfs_create_group(&prng_tdes_dev.this_device->kobj, &prng_tdes_dev_attr_group); if (ret) { misc_deregister(&prng_tdes_dev); prng_tdes_deinstantiate(); goto out; } } out: return ret; } static void __exit prng_exit(void) { if (prng_mode == PRNG_MODE_SHA512) { sysfs_remove_group(&prng_sha512_dev.this_device->kobj, &prng_sha512_dev_attr_group); misc_deregister(&prng_sha512_dev); prng_sha512_deinstantiate(); } else { sysfs_remove_group(&prng_tdes_dev.this_device->kobj, &prng_tdes_dev_attr_group); misc_deregister(&prng_tdes_dev); prng_tdes_deinstantiate(); } } module_cpu_feature_match(MSA, prng_init); module_exit(prng_exit);
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