1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
|
#define _GNU_SOURCE
/* Sealing and TLS for pure-serve (serve/seal.h, serve/tls.h), by way of
* pure-crypto.so (serve/crypto.h): mapped, and OpenSSL with it, the first
* time a server needs it. What needs no OpenSSL (a key's hex, the suite
* this machine seals with) is here. */
#include "crypto.h"
#include <dlfcn.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#if defined(__aarch64__) && defined(__linux__)
#include <asm/hwcap.h>
#include <sys/auxv.h>
#endif
static pthread_once_t once = PTHREAD_ONCE_INIT;
static const PureCrypto *crypto;
static char why[512];
/* pure-crypto.so beside the executable, or where PURE_CRYPTO names it. */
static void load(void) {
char path[4096];
const char *named = getenv("PURE_CRYPTO");
if (named) snprintf(path, sizeof(path), "%s", named);
else {
ssize_t length = readlink("/proc/self/exe", path, sizeof(path) - 32);
char *slash = length > 0 ? memrchr(path, '/', (size_t)length) : NULL;
if (!slash) { snprintf(why, sizeof(why), "pure-crypto.so: cannot find pure-serve's directory"); return; }
strcpy(slash + 1, "pure-crypto.so");
}
void *library = dlopen(path, RTLD_NOW | RTLD_LOCAL);
const PureCrypto *table = library ? dlsym(library, "pure_crypto") : NULL;
if (!table || table->version != PURE_CRYPTO_VERSION) {
snprintf(why, sizeof(why), "%s", !library ? dlerror() : "pure-crypto.so is not this pure-serve's");
return;
}
crypto = table;
}
static const PureCrypto *loaded(char *error, size_t size) {
pthread_once(&once, load);
if (!crypto && error) snprintf(error, size, "%s", why);
return crypto;
}
/* ---- TLS */
bool pure_tls_start(const char *ca_file, char *error, size_t size) {
static int started; /* 1 made, -1 failed; by the thread that opens wires */
const PureCrypto *c = loaded(error, size);
if (!c) return false;
if (!started) started = c->tls_start(ca_file) ? 1 : -1;
if (started < 0) snprintf(error, size, "no TLS context: %s cannot be read", ca_file ? ca_file : "the system's CAs");
return started > 0;
}
/* A session exists only once the table is loaded. */
PureTls *pure_tls_open(const char *host, int fd) { return crypto ? crypto->tls_open(host, fd) : NULL; }
int pure_tls_read(PureTls *tls, void *bytes, int size) { return crypto->tls_read(tls, bytes, size); }
int pure_tls_write(PureTls *tls, const void *bytes, int size) { return crypto->tls_write(tls, bytes, size); }
void pure_tls_close(PureTls *tls) { if (tls) crypto->tls_close(tls); }
/* ---- Sealing */
static const char aes_name[] = "x25519-sha256-aes128gcm", chacha_name[] = "x25519-sha256-chacha20poly1305";
/* AES-GCM where AES is in the CPU (two to three times ChaCha20-Poly1305 from
* a kilobyte up on a Cortex-A76, research 086); ChaCha20-Poly1305, fast in
* plain code, elsewhere. */
static bool has_aes(void) {
#if defined(__aarch64__) && defined(__linux__)
return (getauxval(AT_HWCAP) & HWCAP_AES) && (getauxval(AT_HWCAP) & HWCAP_PMULL);
#elif defined(__x86_64__) && (defined(__GNUC__) || defined(__clang__))
return __builtin_cpu_supports("aes") && __builtin_cpu_supports("pclmul");
#else
return false;
#endif
}
const char *pure_seal_suite(void) { return has_aes() ? aes_name : chacha_name; }
static bool hex_value(char c, unsigned *v) {
if (c >= '0' && c <= '9') *v = (unsigned)(c - '0');
else if (c >= 'a' && c <= 'f') *v = (unsigned)(c - 'a' + 10);
else if (c >= 'A' && c <= 'F') *v = (unsigned)(c - 'A' + 10);
else return false;
return true;
}
bool pure_seal_peer(const char *hex, unsigned char out[PURE_SEAL_KEY]) {
if (strlen(hex) != 2 * PURE_SEAL_KEY) return false;
for (size_t i = 0; i < PURE_SEAL_KEY; ++i) {
unsigned high, low;
if (!hex_value(hex[2 * i], &high) || !hex_value(hex[2 * i + 1], &low)) return false;
out[i] = (unsigned char)(high << 4 | low);
}
return true;
}
bool pure_seal_ready(char *error, size_t size) { return loaded(error, size) != NULL; }
PureSealKey *pure_seal_key(const char *path, char public_hex[2 * PURE_SEAL_KEY + 1], char *error, size_t size) {
const PureCrypto *c = loaded(error, size);
return c ? c->seal_key(path, public_hex, error, size) : NULL;
}
/* A key exists only once the table is loaded. */
void pure_seal_key_free(PureSealKey *key) { if (key) crypto->seal_key_free(key); }
bool pure_seal(const unsigned char peer[PURE_SEAL_KEY], const char *aad, const unsigned char *plain, size_t size,
unsigned char *out) {
const PureCrypto *c = loaded(NULL, 0);
return c && c->seal(pure_seal_suite(), peer, aad, plain, size, out);
}
bool pure_unseal(const PureSealKey *key, const char *suite, const char *aad, const unsigned char *sealed, size_t size,
unsigned char *plain) {
return key && crypto->unseal(key, suite, aad, sealed, size, plain);
}
|
