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-rw-r--r--crypto/apr_crypto_prng.c57
-rw-r--r--include/apr_crypto.h5
-rw-r--r--threadproc/unix/proc.c4
3 files changed, 35 insertions, 31 deletions
diff --git a/crypto/apr_crypto_prng.c b/crypto/apr_crypto_prng.c
index 81363fd2e..ad9a8b839 100644
--- a/crypto/apr_crypto_prng.c
+++ b/crypto/apr_crypto_prng.c
@@ -139,9 +139,8 @@ void cprng_stream_setkey(cprng_stream_ctx_t *ctx,
static APR_INLINE
apr_status_t cprng_stream_ctx_bytes(cprng_stream_ctx_t **pctx,
- unsigned char *key, int rekey,
- unsigned char *to, apr_size_t n,
- const unsigned char *z)
+ unsigned char *key, unsigned char *to,
+ apr_size_t n, const unsigned char *z)
{
cprng_stream_ctx_t *ctx = *pctx;
int len;
@@ -157,9 +156,7 @@ apr_status_t cprng_stream_ctx_bytes(cprng_stream_ctx_t **pctx,
*/
cprng_stream_setkey(ctx, key, z);
EVP_CIPHER_CTX_set_padding(ctx, 0);
- if (rekey) {
- EVP_EncryptUpdate(ctx, key, &len, z, CPRNG_KEY_SIZE);
- }
+ EVP_EncryptUpdate(ctx, key, &len, z, CPRNG_KEY_SIZE);
if (n) {
EVP_EncryptUpdate(ctx, to, &len, z, n);
}
@@ -482,13 +479,11 @@ APR_DECLARE(apr_status_t) apr_crypto_prng_destroy(apr_crypto_prng_t *cprng)
}
static apr_status_t cprng_stream_bytes(apr_crypto_prng_t *cprng,
- void *to, size_t len,
- int rekey)
+ void *to, apr_size_t len)
{
apr_status_t rv;
- rv = cprng_stream_ctx_bytes(&cprng->ctx, cprng->key, rekey,
- to, len, cprng->buf);
+ rv = cprng_stream_ctx_bytes(&cprng->ctx, cprng->key, to, len, cprng->buf);
if (rv != APR_SUCCESS && len) {
apr_crypto_memzero(to, len);
}
@@ -537,7 +532,7 @@ APR_DECLARE(apr_status_t) apr_crypto_prng_reseed(apr_crypto_prng_t *cprng,
* i.e. the next key is always extracted from the stream cipher state
* and cleared upon use.
*/
- rv = cprng_stream_bytes(cprng, NULL, 0, 1);
+ rv = cprng_stream_bytes(cprng, NULL, 0);
}
cprng_unlock(cprng);
@@ -558,7 +553,7 @@ static apr_status_t cprng_bytes(apr_crypto_prng_t *cprng,
n = cprng->len;
if (len >= n) {
do {
- rv = cprng_stream_bytes(cprng, ptr, n, 1);
+ rv = cprng_stream_bytes(cprng, ptr, n);
if (rv != APR_SUCCESS) {
return rv;
}
@@ -569,7 +564,7 @@ static apr_status_t cprng_bytes(apr_crypto_prng_t *cprng,
break;
}
}
- rv = cprng_stream_bytes(cprng, cprng->buf, n, 1);
+ rv = cprng_stream_bytes(cprng, cprng->buf, n);
if (rv != APR_SUCCESS) {
return rv;
}
@@ -616,11 +611,12 @@ APR_DECLARE(apr_status_t) apr_crypto_prng_bytes(apr_crypto_prng_t *cprng,
}
/* Reset the buffer and use the next stream bytes as the new key. */
-static apr_status_t cprng_newkey(apr_crypto_prng_t *cprng, int rekey)
+static apr_status_t cprng_rekey(apr_crypto_prng_t *cprng,
+ unsigned char *newkey)
{
cprng->pos = cprng->len;
apr_crypto_memzero(cprng->buf, cprng->len);
- return cprng_stream_bytes(cprng, cprng->key, CPRNG_KEY_SIZE, rekey);
+ return cprng_stream_bytes(cprng, newkey, newkey ? CPRNG_KEY_SIZE : 0);
}
APR_DECLARE(apr_status_t) apr_crypto_prng_rekey(apr_crypto_prng_t *cprng)
@@ -637,8 +633,8 @@ APR_DECLARE(apr_status_t) apr_crypto_prng_rekey(apr_crypto_prng_t *cprng)
cprng_lock(cprng);
- /* Renew and apply the new key. */
- rv = cprng_newkey(cprng, 1);
+ /* Clear state and renew the key. */
+ rv = cprng_rekey(cprng, NULL);
cprng_unlock(cprng);
@@ -661,9 +657,10 @@ APR_DECLARE(apr_status_t) apr_crypto_prng_rekey(apr_crypto_prng_t *cprng)
#if APR_HAS_FORK
APR_DECLARE(apr_status_t) apr_crypto_prng_after_fork(apr_crypto_prng_t *cprng,
- int in_child)
+ int flags)
{
apr_status_t rv;
+ int child = flags & APR_CRYPTO_FORK_INCHILD;
if (!cprng) {
/* Fall through with global CPRNG. */
@@ -675,16 +672,20 @@ APR_DECLARE(apr_status_t) apr_crypto_prng_after_fork(apr_crypto_prng_t *cprng,
cprng_lock(cprng);
- /* Make sure the parent and child processes never share the same state, so
- * renew the key first (also clears the buffer) for both parent and child,
- * so that further fork()s (from parent or child) won't use the same state.
- * For the parent process only, renew a second time to ensure that key
- * material is different from the child. Finally parent and child keys will
- * be different and unknown to each other processes.
+ /* Make sure the parent and child processes never share the same state,
+ * and that further fork()s from either process will not either.
+ * This is done by rekeying (and clearing the buffers) in both processes,
+ * and by rekeying a second time in the parent process to ensure both that
+ * keys are different and that after apr_crypto_prng_after_fork() is called
+ * the keys are unknown to each other processes.
+ * The new key to be used by the parent process is generated in the same
+ * pass as the rekey, and since cprng_stream_bytes() is designed to burn
+ * and never reuse keys we are sure that this key is unique to the parent,
+ * and that nothing is left over from the initial state in both processes.
*/
- rv = cprng_newkey(cprng, in_child);
- if (rv == APR_SUCCESS && !in_child) {
- rv = cprng_stream_bytes(cprng, cprng->key, CPRNG_KEY_SIZE, 1);
+ rv = cprng_rekey(cprng, child ? NULL : cprng->key);
+ if (rv == APR_SUCCESS && !child) {
+ rv = cprng_rekey(cprng, NULL);
}
cprng_unlock(cprng);
@@ -695,7 +696,7 @@ APR_DECLARE(apr_status_t) apr_crypto_prng_after_fork(apr_crypto_prng_t *cprng,
for (cprng = APR_RING_FIRST(cprng_ring);
cprng != APR_RING_SENTINEL(cprng_ring, apr_crypto_prng_t, link);
cprng = APR_RING_NEXT(cprng, link)) {
- apr_status_t rt = apr_crypto_prng_after_fork(cprng, in_child);
+ apr_status_t rt = apr_crypto_prng_after_fork(cprng, flags);
if (rt != APR_SUCCESS && rv == APR_SUCCESS) {
rv = rt;
}
diff --git a/include/apr_crypto.h b/include/apr_crypto.h
index cd3e636d0..bc92b31b5 100644
--- a/include/apr_crypto.h
+++ b/include/apr_crypto.h
@@ -628,6 +628,9 @@ APR_DECLARE(apr_status_t) apr_crypto_prng_reseed(apr_crypto_prng_t *cprng,
const unsigned char seed[]);
#if APR_HAS_FORK
+#define APR_CRYPTO_FORK_INPARENT 0
+#define APR_CRYPTO_FORK_INCHILD 1
+
/**
* @brief Rekey a CPRNG in the parent and/or child process after a fork(),
* so that they don't share the same state.
@@ -639,7 +642,7 @@ APR_DECLARE(apr_status_t) apr_crypto_prng_reseed(apr_crypto_prng_t *cprng,
* @return Any system error (APR_ENOMEM, ...).
*/
APR_DECLARE(apr_status_t) apr_crypto_prng_after_fork(apr_crypto_prng_t *cprng,
- int in_child);
+ int flags);
#endif
/**
diff --git a/threadproc/unix/proc.c b/threadproc/unix/proc.c
index 950405c09..ed7a05fda 100644
--- a/threadproc/unix/proc.c
+++ b/threadproc/unix/proc.c
@@ -238,7 +238,7 @@ APR_DECLARE(apr_status_t) apr_proc_fork(apr_proc_t *proc, apr_pool_t *pool)
/* Do the work needed for children PRNG(s). */
#if APU_HAVE_CRYPTO_PRNG
- apr_crypto_prng_after_fork(NULL, 1);
+ apr_crypto_prng_after_fork(NULL, APR_CRYPTO_FORK_INCHILD);
#endif
apr_random_after_fork(proc);
@@ -249,7 +249,7 @@ APR_DECLARE(apr_status_t) apr_proc_fork(apr_proc_t *proc, apr_pool_t *pool)
/* Do the work needed for parent PRNG(s). */
#if APU_HAVE_CRYPTO_PRNG
- apr_crypto_prng_after_fork(NULL, 0);
+ apr_crypto_prng_after_fork(NULL, APR_CRYPTO_FORK_INPARENT);
#endif
return APR_INPARENT;
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