add the blob object interface

README.rst

@@ -27,6 +27,8 @@ import blobsha256 [from "path"] ;
 CONTENTS
 ========
 
+* Object blob
+* BLOB blob.hash()
 * BLOB hash(BLOB)
 * Object hmac
 * BLOB hmac.hmac(BLOB)
@@ -46,8 +48,8 @@ Description
 	given ``key``.
 
 Example
-	``new key = blobcode.blob(BASE64, "a2V5");``
-	``new hmac = blobsha256.hmac(key.get());``
+	new key = blobcode.blob(BASE64, "a2V5");
+	new hmac = blobsha256.hmac(key.get());
 
 .. _func_hmac.hmac:
 
@@ -62,7 +64,38 @@ Description
 	``msg`` based on the key provided in the constructor.
 
 Example
-	``set req.http.hmac = hmac.hmac(blobcode.decode(BASE64, "Zm9v"));``
+	set req.http.hmac = hmac.hmac(blobcode.decode(BASE64, "Zm9v"));
+
+.. _obj_blob:
+
+Object blob
+===========
+
+
+Prototype
+	new OBJ = blobsha256.blob(BLOB blob)
+
+Description
+	Creates an object that returns the SHA256 digest of the given
+	``blob``.
+
+Example
+	new key = blobcode.blob(BASE64, "Zm9v");
+	new foo = blobsha256.blob(key.get());
+
+.. _func_blob.hash:
+
+BLOB blob.hash()
+----------------
+
+Prototype
+	BLOB blob.hash()
+
+Description
+	Returns the SHA256 digest for the blob given in the constructor.
+
+Example
+	set req.http.X-Hash = blobcode.encode(BASE64, foo.hash());
 
 .. _func_hash:
 
@@ -87,4 +120,4 @@ Description
 	Returns the version string for this VMOD.
 
 Example
-	``std.log("Using VMOD blobsha256 version " + blobsha256.version());``
+	std.log("Using VMOD blobsha256 version " + blobsha256.version());

src/vmod_blobsha256.c

@@ -60,6 +60,12 @@ struct vmod_blobsha256_hmac {
 	SHA256_CTX outer_ctx;
 };
 
+struct vmod_blobsha256_blob {
+	unsigned magic;
+#define VMOD_BLOBSHA256_BLOB_MAGIC 0x2067c219
+	struct vmod_priv hash;
+};
+
 static void
 errmsg(VRT_CTX, const char *fmt, ...)
 {
@@ -88,7 +94,7 @@ digest(SHA256_CTX *restrict const ctx, VCL_BLOB restrict const b,
 	SHA256_Final(digest, ctx);
 }
 
-/* Objects */
+/* Object hmac */
 
 VCL_VOID
 vmod_hmac__init(VRT_CTX, struct vmod_blobsha256_hmac **hmacp,
@@ -128,6 +134,7 @@ vmod_hmac_hmac(VRT_CTX, struct vmod_blobsha256_hmac *h, VCL_BLOB msg)
 	struct vmod_priv *b;
 	char *snap;
 	SHA256_CTX inner_ctx, outer_ctx;
+	uint8_t inner_digest[SHA256_LEN];
 
 	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
 	CHECK_OBJ_NOTNULL(h, VMOD_BLOBSHA256_HMAC_MAGIC);
@@ -146,7 +153,6 @@ vmod_hmac_hmac(VRT_CTX, struct vmod_blobsha256_hmac *h, VCL_BLOB msg)
 	b->len = SHA256_LEN;
 	b->free = NULL;
 
-	uint8_t inner_digest[SHA256_LEN];
 	memcpy(&inner_ctx, &h->inner_ctx, sizeof(SHA256_CTX));
 	memcpy(&outer_ctx, &h->outer_ctx, sizeof(SHA256_CTX));
 
@@ -172,6 +178,54 @@ vmod_hmac__fini(struct vmod_blobsha256_hmac **hmacp)
 	FREE_OBJ(hmac);
 }
 
+/* Object blob */
+
+VCL_VOID
+vmod_blob__init(VRT_CTX, struct vmod_blobsha256_blob **blobp,
+		const char *vcl_name, VCL_BLOB b)
+{
+	struct vmod_blobsha256_blob *blob;
+	SHA256_CTX hctx[1];
+
+	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
+	AN(blobp);
+	AZ(*blobp);
+	AN(vcl_name);
+	ALLOC_OBJ(blob, VMOD_BLOBSHA256_BLOB_MAGIC);
+	AN(blob);
+	*blobp = blob;
+
+	blob->hash.priv = malloc(SHA256_LEN);
+	if (blob->hash.priv == NULL) {
+		ERRNOMEM(ctx, "allocating hash in blob constructor");
+		return;
+	}
+
+	blob->hash.len = SHA256_LEN;
+	blob->hash.free = NULL;
+	digest(hctx, b, blob->hash.priv);
+}
+
+VCL_BLOB
+vmod_blob_hash(VRT_CTX, struct vmod_blobsha256_blob *blob)
+{
+	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
+	CHECK_OBJ_NOTNULL(blob, VMOD_BLOBSHA256_BLOB_MAGIC);
+	return &blob->hash;
+}
+
+VCL_VOID
+vmod_blob__fini(struct vmod_blobsha256_blob **blobp)
+{
+	struct vmod_blobsha256_blob *blob;
+
+	AN(*blobp);
+	blob = *blobp;
+	*blobp = NULL;
+	CHECK_OBJ_NOTNULL(blob, VMOD_BLOBSHA256_BLOB_MAGIC);
+	FREE_OBJ(blob);
+}
+
 /* Functions */
 
 VCL_BLOB

src/vmod_blobsha256.vcc

@@ -19,8 +19,8 @@ Description
 	given ``key``.
 
 Example
-	``new key = blobcode.blob(BASE64, "a2V5");``
-	``new hmac = blobsha256.hmac(key.get());``
+	new key = blobcode.blob(BASE64, "a2V5");
+	new hmac = blobsha256.hmac(key.get());
 
 $Method BLOB .hmac(BLOB msg)
 
@@ -29,7 +29,28 @@ Description
 	``msg`` based on the key provided in the constructor.
 
 Example
-	``set req.http.hmac = hmac.hmac(blobcode.decode(BASE64, "Zm9v"));``
+	set req.http.hmac = hmac.hmac(blobcode.decode(BASE64, "Zm9v"));
+
+$Object blob(BLOB blob)
+
+Prototype
+	new OBJ = blobsha256.blob(BLOB blob)
+
+Description
+	Creates an object that returns the SHA256 digest of the given
+	``blob``.
+
+Example
+	new key = blobcode.blob(BASE64, "Zm9v");
+	new foo = blobsha256.blob(key.get());
+
+$Method BLOB .hash()
+
+Description
+	Returns the SHA256 digest for the blob given in the constructor.
+
+Example
+	set req.http.X-Hash = blobcode.encode(BASE64, foo.hash());
 
 $Function BLOB hash(BLOB msg)
 
@@ -42,4 +63,4 @@ Description
 	Returns the version string for this VMOD.
 
 Example
-	``std.log("Using VMOD blobsha256 version " + blobsha256.version());``
+	std.log("Using VMOD blobsha256 version " + blobsha256.version());