Avoid allocating packet buffers unnecessarily.

[meshlink] / src / crypto.c

diff --git a/src/crypto.c b/src/crypto.c
index cf000c8a0824f855a1f6e6815603e00500c6ed33..3244a0b4628bdd2e6ddb6f49dbf1a0c30fab17ad 100644 (file)
--- a/src/crypto.c
+++ b/src/crypto.c
@@ -23,12 +23,19 @@
 
 //TODO: use a strict random source once to seed a PRNG?
 
+#ifndef HAVE_MINGW
+
 static int random_fd = -1;
 
 void crypto_init(void) {
+       assert(random_fd == -1);
+
        random_fd = open("/dev/urandom", O_RDONLY);
-       if(random_fd < 0)
+
+       if(random_fd < 0) {
                random_fd = open("/dev/random", O_RDONLY);
+       }
+
        if(random_fd < 0) {
                fprintf(stderr, "Could not open source of random numbers: %s\n", strerror(errno));
                abort();
@@ -36,11 +43,57 @@ void crypto_init(void) {
 }
 
 void crypto_exit(void) {
+       assert(random_fd != -1);
+
+       close(random_fd);
+       random_fd = -1;
+}
+
+void randomize(void *out, size_t outlen) {
+       assert(outlen);
+
+       char *ptr = out;
+
+       while(outlen) {
+               size_t len = read(random_fd, ptr, outlen);
+
+               if(len <= 0) {
+                       if(errno == EAGAIN || errno == EINTR) {
+                               continue;
+                       }
+
+                       fprintf(stderr, "Could not read random numbers: %s\n", strerror(errno));
+                       abort();
+               }
+
+               ptr += len;
+               outlen -= len;
+       }
+}
+
+#else
+
+#include <wincrypt.h>
+HCRYPTPROV prov;
+
+void crypto_init(void) {
+       if(!CryptAcquireContext(&prov, NULL, NULL, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT)) {
+               fprintf(stderr, "CryptAcquireContext() failed!\n");
+               abort();
+       }
+}
+
+void crypto_exit(void) {
+       CryptReleaseContext(prov, 0);
 }
 
 void randomize(void *out, size_t outlen) {
-       if(read(random_fd, out, outlen) != outlen) {
-               fprintf(stderr, "Error reading random numbers: %s\n", strerror(errno));
+       assert(outlen);
+
+       if(!CryptGenRandom(prov, outlen, out)) {
+               fprintf(stderr, "CryptGenRandom() failed\n");
                abort();
        }
 }
+
+#endif