1 files changed, 44 insertions, 0 deletions

diff --git a/src/apk_blob.h b/src/apk_blob.h
index 9ad79c4..170cf20 100644
--- a/src/apk_blob.h
+++ b/src/apk_blob.h
@@ -13,6 +13,8 @@
 #define APK_BLOB_H
 
 #include <string.h>
+#include <openssl/evp.h>
+
 #include "apk_defines.h"
 
 struct apk_blob {
@@ -22,10 +24,38 @@ struct apk_blob {
 typedef struct apk_blob apk_blob_t;
 typedef int (*apk_blob_cb)(void *ctx, apk_blob_t blob);
 
+#define APK_CHECKSUM_NONE	0
+#define APK_CHECKSUM_MD5	16
+#define APK_CHECKSUM_SHA1	20
+
+/* Internal cointainer for MD5 or SHA1 */
+struct apk_checksum {
+	unsigned char data[20];
+	unsigned char type;
+};
+
+static inline const EVP_MD *apk_default_checksum(void)
+{
+	return EVP_sha1();
+}
+
+static inline const EVP_MD *apk_get_digest(int type)
+{
+	switch (type) {
+	case APK_CHECKSUM_MD5:
+		return EVP_md5();
+	case APK_CHECKSUM_SHA1:
+		return EVP_sha1();
+	}
+	return EVP_md_null();
+}
+
 #define APK_BLOB_IS_NULL(blob)		((blob).ptr == NULL)
 
 #define APK_BLOB_NULL			((apk_blob_t){0, NULL})
 #define APK_BLOB_BUF(buf)		((apk_blob_t){sizeof(buf), (char *)(buf)})
+#define APK_BLOB_CSUM(csum)		((apk_blob_t){(csum).type, (char *)(csum).data})
+#define APK_BLOB_STRUCT(s)		((apk_blob_t){sizeof(s), (char*)&(s)})
 #define APK_BLOB_PTR_LEN(beg,len)	((apk_blob_t){(len), (beg)})
 #define APK_BLOB_PTR_PTR(beg,end)	APK_BLOB_PTR_LEN((beg),(end)-(beg)+1)
 
@@ -47,12 +77,26 @@ int apk_blob_compare(apk_blob_t a, apk_blob_t b);
 int apk_blob_for_each_segment(apk_blob_t blob, const char *split,
 			      apk_blob_cb cb, void *ctx);
 
+static inline void apk_blob_checksum(apk_blob_t b, const EVP_MD *md, struct apk_checksum *csum)
+{
+	csum->type = EVP_MD_size(md);
+	EVP_Digest(b.ptr, b.len, csum->data, NULL, md, NULL);
+}
+static inline const int apk_checksum_compare(const struct apk_checksum *a,
+					     const struct apk_checksum *b)
+{
+	return apk_blob_compare(APK_BLOB_PTR_LEN((char *) a->data, a->type),
+				APK_BLOB_PTR_LEN((char *) b->data, b->type));
+}
+
 void apk_blob_push_blob(apk_blob_t *to, apk_blob_t literal);
 void apk_blob_push_uint(apk_blob_t *to, unsigned int value, int radix);
+void apk_blob_push_csum(apk_blob_t *to, struct apk_checksum *csum);
 void apk_blob_push_hexdump(apk_blob_t *to, apk_blob_t binary);
 
 void apk_blob_pull_char(apk_blob_t *b, int expected);
 unsigned int apk_blob_pull_uint(apk_blob_t *b, int radix);
+void apk_blob_pull_csum(apk_blob_t *b, struct apk_checksum *csum);
 void apk_blob_pull_hexdump(apk_blob_t *b, apk_blob_t to);
 
 #endif