digest/openssl: adapt to new OpenSSL API

Signed-off-by: Gustavo Lima Chaves <[email protected]>

Author: Gustavo Lima Chaves

src/lib/crypto/sol-message-digest-common.c

@@ -77,6 +77,7 @@ struct sol_message_digest_pending_dispatch {
 struct sol_message_digest {
     void (*on_digest_ready)(void *data, struct sol_message_digest *handle, struct sol_blob *output);
     void (*on_feed_done)(void *data, struct sol_message_digest *handle, struct sol_blob *input, int status);
+    void (*context_free)(void *context_handle);
     const void *data;
     const struct sol_message_digest_common_ops *ops;
 #ifdef MESSAGE_DIGEST_USE_THREAD
@@ -249,11 +250,18 @@ void *
 sol_message_digest_common_get_context(const struct sol_message_digest *handle)
 {
     size_t padding = sizeof(struct sol_message_digest) % sizeof(void *);
+    void *ctx, **pctx;
 
     if (padding > 0)
         padding = sizeof(void *) - padding;
 
-    return (char *)handle + sizeof(struct sol_message_digest) + padding;
+    ctx = (char *)handle + sizeof(struct sol_message_digest) + padding;
+    pctx = ctx;
+
+    if (!handle->context_free)
+        return ctx;
+    else
+        return *pctx;
 }
 
 struct sol_message_digest *
@@ -263,6 +271,7 @@ sol_message_digest_common_new(const struct sol_message_digest_common_new_params
     struct sol_message_digest *handle;
     size_t padding;
     int errno_bkp;
+    void *context;
 
     SOL_NULL_CHECK(params.ops, NULL);
     SOL_NULL_CHECK(params.ops->feed, NULL);
@@ -274,13 +283,24 @@ sol_message_digest_common_new(const struct sol_message_digest_common_new_params
     if (padding > 0)
         padding = sizeof(void *) - padding;
 
-    handle = calloc(1, sizeof(struct sol_message_digest) + padding + params.context_size);
+    if (params.context_handle && !params.context_free) {
+        SOL_WRN("a handle freeing function has to be set for external handlers");
+        errno = EINVAL;
+        return NULL;
+    }
+
+    handle = calloc(1, sizeof(struct sol_message_digest) + padding +
+        (params.context_handle ? sizeof(void *) : params.context_size));
     SOL_NULL_CHECK(handle, NULL);
 
-    if (params.context_template) {
-        void *context = (char *)handle + sizeof(struct sol_message_digest) + padding;
+    context = (char *)handle + sizeof(struct sol_message_digest) + padding;
+
+    if (params.context_handle) {
+        void **pctx = context;
+        *pctx = (void *)params.context_handle;
+        handle->context_free = params.context_free;
+    } else if (params.context_template)
         memcpy(context, params.context_template, params.context_size);
-    }
 
     handle->ops = params.ops;
 
@@ -333,6 +353,9 @@ _sol_message_digest_free(struct sol_message_digest *handle)
 
     handle->ops->cleanup(handle);
 
+    if (handle->context_free)
+        handle->context_free(sol_message_digest_common_get_context(handle));
+
     free(handle);
 }
 

src/lib/crypto/sol-message-digest-common.h

@@ -130,6 +130,23 @@ struct sol_message_digest_common_new_params {
      * sol_message_digest_common_get_context().
      */
     const void *context_template;
+    /**
+     * The algorithm-specific context as an external handle (i.e. life
+     * cycle not managed by Soletta). If set, context_template will be
+     * ignored and context_size will be set to sizeof(void *) forcibly
+     * in order to accomodate this pointer exactly. context_free()
+     * must be set when this one is non-NULL.
+     *
+     * The actual context may be retrieved with
+     * sol_message_digest_common_get_context().
+     */
+    const void *context_handle;
+    /**
+     * Free external context handle at exit.
+     *
+     * This function is called from the main thread.
+     */
+    void (*context_free)(void *context_handle);
     /**
      * Size in bytes of @c context_template, to copy with @c memcpy().
      */

src/lib/crypto/sol-message-digest-impl-openssl.c

@@ -43,19 +43,18 @@ _sol_message_digest_evp_init(struct sol_message_digest *handle, const EVP_MD *md
 {
     EVP_MD_CTX *ctx = sol_message_digest_common_get_context(handle);
 
-    EVP_MD_CTX_init(ctx);
     if (EVP_DigestInit_ex(ctx, md, NULL))
         return 0;
 
     return -EINVAL;
 }
 
 static void
-_sol_message_digest_evp_cleanup(struct sol_message_digest *handle)
+_sol_message_digest_evp_reset(struct sol_message_digest *handle)
 {
     EVP_MD_CTX *ctx = sol_message_digest_common_get_context(handle);
 
-    EVP_MD_CTX_cleanup(ctx);
+    EVP_MD_CTX_reset(ctx);
 }
 
 static ssize_t
@@ -87,27 +86,29 @@ _sol_message_digest_evp_read_digest(struct sol_message_digest *handle, void *mem
 static const struct sol_message_digest_common_ops _sol_message_digest_evp_ops = {
     .feed = _sol_message_digest_evp_feed,
     .read_digest = _sol_message_digest_evp_read_digest,
-    .cleanup = _sol_message_digest_evp_cleanup
+    .cleanup = _sol_message_digest_evp_reset
 };
 
 static int
 _sol_message_digest_hmac_init(struct sol_message_digest *handle, const EVP_MD *md, const struct sol_str_slice key)
 {
-    HMAC_CTX *ctx = sol_message_digest_common_get_context(handle);
+    HMAC_CTX *ctx = HMAC_CTX_new();
+
+    if (!ctx)
+        return -ENOMEM;
 
-    HMAC_CTX_init(ctx);
     if (HMAC_Init_ex(ctx, key.data, key.len, md, NULL))
         return 0;
 
     return -EINVAL;
 }
 
 static void
-_sol_message_digest_hmac_cleanup(struct sol_message_digest *handle)
+_sol_message_digest_hmac_reset(struct sol_message_digest *handle)
 {
     HMAC_CTX *ctx = sol_message_digest_common_get_context(handle);
 
-    HMAC_CTX_cleanup(ctx);
+    HMAC_CTX_reset(ctx);
 }
 
 static ssize_t
@@ -139,7 +140,7 @@ _sol_message_digest_hmac_read_digest(struct sol_message_digest *handle, void *me
 static const struct sol_message_digest_common_ops _sol_message_digest_hmac_ops = {
     .feed = _sol_message_digest_hmac_feed,
     .read_digest = _sol_message_digest_hmac_read_digest,
-    .cleanup = _sol_message_digest_hmac_cleanup
+    .cleanup = _sol_message_digest_hmac_reset
 };
 
 SOL_API struct sol_message_digest *
@@ -172,17 +173,19 @@ sol_message_digest_new(const struct sol_message_digest_config *config)
 
     params.config = config;
     params.ops = NULL;
-    params.context_template = NULL;
 
     md = EVP_get_digestbyname(config->algorithm);
     if (md) {
+        params.context_handle = EVP_MD_CTX_new();
+        params.context_free = (void (*)(void *))EVP_MD_CTX_free;
         init_fn = _sol_message_digest_evp_init;
         params.ops = &_sol_message_digest_evp_ops;
-        params.context_size = sizeof(EVP_MD_CTX);
         SOL_DBG("using evp, md=%p, algorithm=\"%s\"", md, config->algorithm);
     } else if (streqn(config->algorithm, "hmac(", strlen("hmac("))) {
         const char *p = config->algorithm + strlen("hmac(");
         size_t len = strlen(p);
+        params.context_handle = HMAC_CTX_new();
+        params.context_free = (void (*)(void *))HMAC_CTX_free;
         if (len > 1 && p[len - 1] == ')') {
             char *mdname = strndupa(p, len - 1);
             md = EVP_get_digestbyname(mdname);
@@ -193,7 +196,6 @@ sol_message_digest_new(const struct sol_message_digest_config *config)
             }
             init_fn = _sol_message_digest_hmac_init;
             params.ops = &_sol_message_digest_hmac_ops;
-            params.context_size = sizeof(HMAC_CTX);
             SOL_DBG("using hmac, md=%p, algorithm=\"%s\"", md, mdname);
         }
     }