sha1: Add functions, macros for converting digests to and from strings.

These will be used in the upcoming OVSDB.

The SHA1_FMT and SHA1_ARGS macros are arguably absurd, but they are
also convenient.

1 files changed, 17 insertions, 2 deletions

diff --git a/lib/sha1.h b/lib/sha1.h
index 75d3533d..9a372775 100644
--- a/lib/sha1.h
+++ b/lib/sha1.h
@@ -29,11 +29,12 @@
 #ifndef SHA1_H
 #define SHA1_H
 
+#include <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>
 
-/* Size of the SHA1 digest. */
-#define SHA1_DIGEST_SIZE 20
+#define SHA1_DIGEST_SIZE 20     /* Size of the SHA1 digest. */
+#define SHA1_HEX_DIGEST_LEN 40  /* Length of SHA1 digest as hex in ASCII. */
 
 /* SHA1 context structure. */
 struct sha1_ctx {
@@ -48,4 +49,18 @@ void sha1_update(struct sha1_ctx *, const void *, size_t);
 void sha1_final(struct sha1_ctx *, uint8_t digest[SHA1_DIGEST_SIZE]);
 void sha1_bytes(const void *, size_t, uint8_t digest[SHA1_DIGEST_SIZE]);
 
+#define SHA1_FMT \
+        "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x" \
+        "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x"
+#define SHA1_ARGS(DIGEST) \
+    ((DIGEST)[0]), ((DIGEST)[1]), ((DIGEST)[2]), ((DIGEST)[3]), \
+    ((DIGEST)[4]), ((DIGEST)[5]), ((DIGEST)[6]), ((DIGEST)[7]), \
+    ((DIGEST)[8]), ((DIGEST)[9]), ((DIGEST)[10]), ((DIGEST)[11]), \
+    ((DIGEST)[12]), ((DIGEST)[13]), ((DIGEST)[14]), ((DIGEST)[15]), \
+    ((DIGEST)[16]), ((DIGEST)[17]), ((DIGEST)[18]), ((DIGEST)[19])
+
+void sha1_to_hex(const uint8_t digest[SHA1_DIGEST_SIZE],
+                 char hex[SHA1_HEX_DIGEST_LEN + 1]);
+bool sha1_from_hex(uint8_t digest[SHA1_DIGEST_SIZE], const char *hex);
+
 #endif  /* sha1.h */