Add support for salt for BLAKE

Signed-off-by: Mattias Andrée <maandree@kth.se>

1 files changed, 28 insertions, 4 deletions

diff --git a/libhashsum_init_blake256_hasher.c b/libhashsum_init_blake256_hasher.c
index 202dc37..fd77878 100644
--- a/libhashsum_init_blake256_hasher.c
+++ b/libhashsum_init_blake256_hasher.c
@@ -68,12 +68,35 @@ finalise(struct libhashsum_hasher *this, void *data, size_t bytes, unsigned extr
 }
 
 
+static const char *
+mkalgostr(char *buf, const char *name, const uint8_t *salt)
+{
+	char *p;
+	size_t i;
+	if (!salt)
+		return name;
+	for (i = 0; i < 16U; i++)
+		if (salt[i])
+			goto nonzero;
+	return name;
+nonzero:
+	p = stpcpy(stpcpy(buf, name), "[salt=");
+	for (i = 0; i < 16U; i++) {
+		*p++ = "0123456789abcdef"[(salt[i] >> 4) & 15];
+		*p++ = "0123456789abcdef"[(salt[i] >> 0) & 15];
+	}
+	*p++ = ']';
+	*p++ = '\0';
+	return buf;
+}
+
+
 int
-libhashsum_init_blake256_hasher(struct libhashsum_hasher *this)
+libhashsum_init_blake256_hasher(struct libhashsum_hasher *this, const void *salt)
 {
 	libblake_init();
 	this->algorithm = LIBHASHSUM_BLAKE256;
-	this->algorithm_string = "BLAKE256";
+	this->algorithm_string = mkalgostr(this->state.blake224.algostr, "BLAKE256", salt);
 	this->input_block_size = 64U;
 	this->hash_size = LIBHASHSUM_BLAKE256_HASH_SIZE;
 	this->hash_output = NULL;
@@ -82,16 +105,17 @@ libhashsum_init_blake256_hasher(struct libhashsum_hasher *this)
 	this->finalise_const = &finalise_const;
 	this->finalise = &finalise;
 	this->destroy = NULL;
-	libblake_blake256_init2(&this->state.blake256.s, NULL);
+	libblake_blake256_init2(&this->state.blake256.s, salt);
 	return 0;
 }
 
 
 #else
 int
-libhashsum_init_blake256_hasher(struct libhashsum_hasher *this)
+libhashsum_init_blake256_hasher(struct libhashsum_hasher *this, const void *salt)
 {
 	(void) this;
+	(void) salt;
 	errno = ENOSYS;
 	return -1;
 }