apr_crypto: Clear out buffers that are allocated by us when the pool from

which the memory was allocated from is cleaned up.


git-svn-id: https://svn.apache.org/repos/asf/apr/apr/trunk@1210524 13f79535-47bb-0310-9956-ffa450edef68

3 files changed, 37 insertions, 0 deletions

diff --git a/crypto/apr_crypto.c b/crypto/apr_crypto.c
index 4b28dd2e2..4484cae3b 100644
--- a/crypto/apr_crypto.c
+++ b/crypto/apr_crypto.c
@@ -56,6 +56,11 @@ APR_TYPEDEF_STRUCT(apr_crypto_block_t,
     const apr_crypto_t *f;
 )
 
+typedef struct apr_crypto_clear_t {
+    void *buffer;
+    apr_size_t size;
+} apr_crypto_clear_t;
+
 #if !APR_HAVE_MODULAR_DSO
 #define DRIVER_LOAD(name,driver,pool,params) \
     {   \
@@ -118,6 +123,31 @@ APR_DECLARE(apr_status_t) apr_crypto_init(apr_pool_t *pool)
     return ret;
 }
 
+static apr_status_t crypto_clear(void *ptr)
+{
+    apr_crypto_clear_t *clear = (apr_crypto_clear_t *)ptr;
+
+    memset(clear->buffer, 0, clear->size);
+    clear->buffer = NULL;
+    clear->size = 0;
+
+    return APR_SUCCESS;
+}
+
+APR_DECLARE(apr_status_t) apr_crypto_clear(apr_pool_t *pool,
+        void *buffer, apr_size_t size)
+{
+    apr_crypto_clear_t *clear = apr_palloc(pool, sizeof(apr_crypto_clear_t));
+
+    clear->buffer = buffer;
+    clear->size = size;
+
+    apr_pool_cleanup_register(pool, clear, crypto_clear,
+            apr_pool_cleanup_null);
+
+    return APR_SUCCESS;
+}
+
 APR_DECLARE(apr_status_t) apr_crypto_get_driver(
         const apr_crypto_driver_t **driver, const char *name,
         const char *params, const apu_err_t **result, apr_pool_t *pool)
diff --git a/crypto/apr_crypto_nss.c b/crypto/apr_crypto_nss.c
index bb5c3756d..e52fe99bd 100644
--- a/crypto/apr_crypto_nss.c
+++ b/crypto/apr_crypto_nss.c
@@ -551,6 +551,7 @@ static apr_status_t crypto_block_encrypt_init(apr_crypto_block_t **ctx,
             if (!usedIv) {
                 return APR_ENOMEM;
             }
+            apr_crypto_clear(p, usedIv, key->ivSize);
             s = PK11_GenerateRandom(usedIv, key->ivSize);
             if (s != SECSuccess) {
                 return APR_ENOIV;
@@ -622,6 +623,7 @@ static apr_status_t crypto_block_encrypt(unsigned char **out,
         if (!buffer) {
             return APR_ENOMEM;
         }
+        apr_crypto_clear(block->pool, buffer, inlen + block->blockSize);
         *out = buffer;
     }
 
@@ -785,6 +787,7 @@ static apr_status_t crypto_block_decrypt(unsigned char **out,
         if (!buffer) {
             return APR_ENOMEM;
         }
+        apr_crypto_clear(block->pool, buffer, inlen + block->blockSize);
         *out = buffer;
     }
 
diff --git a/crypto/apr_crypto_openssl.c b/crypto/apr_crypto_openssl.c
index 4708ecd36..993fa9f50 100644
--- a/crypto/apr_crypto_openssl.c
+++ b/crypto/apr_crypto_openssl.c
@@ -431,6 +431,7 @@ static apr_status_t crypto_passphrase(apr_crypto_key_t **k, apr_size_t *ivSize,
     if (!key->key) {
         return APR_ENOMEM;
     }
+    apr_crypto_clear(p, key->key, key->keyLen);
 
     /* generate the key */
     if (PKCS5_PBKDF2_HMAC_SHA1(pass, passLen, (unsigned char *) salt, saltLen,
@@ -504,6 +505,7 @@ static apr_status_t crypto_block_encrypt_init(apr_crypto_block_t **ctx,
             if (!usedIv) {
                 return APR_ENOMEM;
             }
+            apr_crypto_clear(p, usedIv, key->ivSize);
             if (!((RAND_status() == 1)
                     && (RAND_bytes(usedIv, key->ivSize) == 1))) {
                 return APR_ENOIV;
@@ -575,6 +577,7 @@ static apr_status_t crypto_block_encrypt(unsigned char **out,
         if (!buffer) {
             return APR_ENOMEM;
         }
+        apr_crypto_clear(ctx->pool, buffer, inlen + EVP_MAX_BLOCK_LENGTH);
         *out = buffer;
     }
 
@@ -729,6 +732,7 @@ static apr_status_t crypto_block_decrypt(unsigned char **out,
         if (!buffer) {
             return APR_ENOMEM;
         }
+        apr_crypto_clear(ctx->pool, buffer, inlen + EVP_MAX_BLOCK_LENGTH);
         *out = buffer;
     }