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#include "mbedtls.h"
#include "util_ct.h"
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#include <time.h>
#include <mbedtls/ssl.h>
#include <mbedtls/entropy_poll.h>
int prne_mbedtls_x509_crt_verify_cb (void *param, mbedtls_x509_crt *crt, int crt_depth, uint32_t *flags) {
*flags &= ~MBEDTLS_X509_BADCERT_EXPIRED;
return 0;
}
int prne_mbedtls_ssl_send_cb (void *ctx, const unsigned char *buf, size_t len) {
const int fd = *(int*)ctx;
ssize_t ret;
ret = write(fd, buf, len);
if (ret < 0) {
switch (errno) {
#if EAGAIN == EWOULDBLOCK
case EAGAIN:
#else
case EAGAIN:
case EWOULDBLOCK:
#endif
return MBEDTLS_ERR_SSL_WANT_WRITE;
}
}
return ret;
}
int prne_mbedtls_ssl_recv_cb (void *ctx, unsigned char *buf, size_t len) {
const int fd = *(int*)ctx;
ssize_t ret;
ret = read(fd, buf, len);
if (ret < 0) {
switch (errno) {
#if EAGAIN == EWOULDBLOCK
case EAGAIN:
#else
case EAGAIN:
case EWOULDBLOCK:
#endif
return MBEDTLS_ERR_SSL_WANT_READ;
}
}
return ret;
}
static int prne_mbedtls_entropy_urand_src_f (void *data, unsigned char *output, size_t len, size_t *olen) {
const int fd = open("/dev/urandom", O_RDONLY);
int func_ret = 0;
if (fd < 0 || read(fd, output, len) != (ssize_t)len) {
func_ret = MBEDTLS_ERR_ENTROPY_SOURCE_FAILED;
}
*olen = len;
if (fd >= 0) {
close(fd);
}
return func_ret;
}
typedef struct {
pid_t pid;
pid_t ppid;
clock_t clock;
struct timespec now;
struct timespec datetime;
} ent_buf_t;
static int prne_mbedtls_entropy_proc_src_f (void *data, unsigned char *output, size_t len, size_t *olen) {
ent_buf_t buf;
memzero(&buf, sizeof(buf));
buf.pid = getpid();
buf.ppid = getppid();
buf.clock = clock();
clock_gettime(CLOCK_MONOTONIC, &buf.now);
clock_gettime(CLOCK_REALTIME, &buf.datetime);
*olen = prne_op_min(len, sizeof(buf));
memcpy(output, &buf, sizeof(*olen));
return 0;
}
void prne_mbedtls_entropy_init (mbedtls_entropy_context *ctx) {
mbedtls_entropy_init(ctx);
// Remove platform source, which could call getrandom()
for (int i = 0; i < ctx->source_count; i += 1) {
if (ctx->source[i].f_source == mbedtls_platform_entropy_poll) {
memmove(ctx->source + i, ctx->source + i + 1, sizeof(mbedtls_entropy_source_state) * (ctx->source_count - i - 1));
ctx->source_count -= 1;
// Add our own implementation as the one just got removed could be the only source.
mbedtls_entropy_add_source(ctx, prne_mbedtls_entropy_urand_src_f, NULL, MBEDTLS_ENTROPY_MIN_PLATFORM, MBEDTLS_ENTROPY_SOURCE_STRONG);
mbedtls_entropy_add_source(ctx, prne_mbedtls_entropy_proc_src_f, NULL, sizeof(ent_buf_t), MBEDTLS_ENTROPY_SOURCE_STRONG);
break;
}
}
}
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