Add standard_partial_byte_input_encoding and standard_partial_byte_output_encoding

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

18 files changed, 116 insertions, 0 deletions

diff --git a/libhashsum.h b/libhashsum.h
index 297c62c..cf13a2e 100644
--- a/libhashsum.h
+++ b/libhashsum.h
@@ -325,6 +325,19 @@ enum libhashsum_algorithm {
 
 
 /**
+ * Which bits in non-whole octets are used
+ * 
+ * @since  1.0
+ */
+enum {
+	/* since 1.0 */
+	LIBHASHSUM_UNSUPPORTED = 0,       /**< Non-whole octets are unsupport */
+	LIBHASHSUM_LEAST_SIGNIFICANT = 1, /**< The least significant bits of a non-whole octet are used */
+	LIBHASHSUM_MOST_SIGNIFICANT = 2   /**< The most significant bits of a non-whole octet are used */
+};
+
+
+/**
  * Message hash functions and state
  * 
  * @since  1.0
@@ -384,6 +397,75 @@ struct libhashsum_hasher {
 	unsigned char supports_non_whole_bytes;
 
 	/**
+	 * libhashsum always uses the least significant bits of
+	 * a non-whole octet, however every hash function that
+	 * supports non-whole input octets specify their own standard
+	 * for how non-whole octet are encoded. This field will be
+	 * set to specify the standard used for the hash function.
+	 * 
+	 * If this field is set to `LIBHASHSUM_UNSUPPORTED`,
+	 * `.supports_non_whole_bytes` will be 0, and non-whole
+	 * input bytes are unsupported.
+	 * 
+	 * If this field is set to `LIBHASHSUM_LEAST_SIGNIFICANT`,
+	 * `.supports_non_whole_bytes` will be 1, and the standard
+	 * used by the hash function is the same as in libhashsum
+	 * (the least significant bits are used), and no conversion
+	 * between the hash function's standard and libhashsum's
+	 * standard is required for input messages.
+	 * 
+	 * If this field is set to `LIBHASHSUM_MOST_SIGNIFICANT`,
+	 * `.supports_non_whole_bytes` will be 1, and the standard
+	 * used by the hash function is the opposite of libhashsum's
+	 * standard, thus if you have reference input message with
+	 * a partial final byte (where the most significant bits are
+	 * used, and the least significant bits are discarded), you
+	 * have to reverse the bits in the last octet before
+	 * inputing it to `*.finalise` or `*.finalise_const`.
+	 * 
+	 * If you are creating your own message, you always store
+	 * the used bits, in a non-whole octet, in the least
+	 * significant part of the octet, when inputing it to
+	 * `*.finalise` or `*.finalise_const`.
+	 * 
+	 * @since  1.0
+	 */
+	unsigned char standard_partial_byte_input_encoding; /* TODO man, test */
+
+	/**
+	 * libhashsum always uses the least significant bits of
+	 * a non-while octet, however every hash function that
+	 * supports non-whole output octets specify their own standard
+	 * for how non-whole octets are encoded. This field will be
+	 * set to specify the standard used for the hash function.
+	 * 
+	 * If this field is set to `LIBHASHSUM_UNSUPPORTED`, non-whole
+	 * output bytees are unsupported.
+	 * 
+	 * If this field is set to `LIBHASHSUM_LEAST_SIGNIFICANT`,
+	 * the standard used by the hash function is the same as in
+	 * libhashsum (the least significant bits are used), and no
+	 * conversion between the hash function's standard and
+	 * libhashsum's standard is required for hashes.
+	 * 
+	 * If this field is set to `LIBHASHSUM_MOST_SIGNIFICANT`,
+	 * the standard used by the hash function is the opposite of
+	 * libhashsum's standard, thus if you have reference hash
+	 * with a partial final byte (where the most significant bits
+	 * are used, and the least significant bits are unused), you
+	 * have to reverse the bits in the last octet before comparing
+	 * the reference hash with the output of `*.finalise` and
+	 * `*.finalise_const`.
+	 * 
+	 * The text above assumes that the hash function's standard
+	 * is to always clear unused bits; this is also always done
+	 * by `*.finalise` and `*.finalise_const`.
+	 * 
+	 * @since  1.0
+	 */
+	unsigned char standard_partial_byte_output_encoding; /* TODO man, test */
+
+	/**
 	 * Update the hash state given additional
 	 * input data
 	 * 
diff --git a/libhashsum_init_blake224_hasher.c b/libhashsum_init_blake224_hasher.c
index f4b0726..1bd9103 100644
--- a/libhashsum_init_blake224_hasher.c
+++ b/libhashsum_init_blake224_hasher.c
@@ -105,6 +105,8 @@ libhashsum_init_blake224_hasher(struct libhashsum_hasher *this, const void *salt
 	this->hash_size = LIBHASHSUM_BLAKE224_HASH_SIZE;
 	this->hash_output = NULL;
 	this->supports_non_whole_bytes = 1;
+	this->standard_partial_byte_input_encoding = LIBHASHSUM_MOST_SIGNIFICANT;
+	this->standard_partial_byte_output_encoding = LIBHASHSUM_UNSUPPORTED;
 	this->process = &process;
 	this->finalise_const = &finalise_const;
 	this->finalise = &finalise;
diff --git a/libhashsum_init_blake256_hasher.c b/libhashsum_init_blake256_hasher.c
index 3d00290..2dc9c8c 100644
--- a/libhashsum_init_blake256_hasher.c
+++ b/libhashsum_init_blake256_hasher.c
@@ -105,6 +105,8 @@ libhashsum_init_blake256_hasher(struct libhashsum_hasher *this, const void *salt
 	this->hash_size = LIBHASHSUM_BLAKE256_HASH_SIZE;
 	this->hash_output = NULL;
 	this->supports_non_whole_bytes = 1;
+	this->standard_partial_byte_input_encoding = LIBHASHSUM_MOST_SIGNIFICANT;
+	this->standard_partial_byte_output_encoding = LIBHASHSUM_UNSUPPORTED;
 	this->process = &process;
 	this->finalise_const = &finalise_const;
 	this->finalise = &finalise;
diff --git a/libhashsum_init_blake2b_hasher.c b/libhashsum_init_blake2b_hasher.c
index 06504d3..4172001 100644
--- a/libhashsum_init_blake2b_hasher.c
+++ b/libhashsum_init_blake2b_hasher.c
@@ -167,6 +167,8 @@ libhashsum_init_blake2b_hasher(struct libhashsum_hasher *this, size_t hashbits,
 	this->hash_size = hashbits / 8U;
 	this->hash_output = NULL;
 	this->supports_non_whole_bytes = 0;
+	this->standard_partial_byte_input_encoding = LIBHASHSUM_UNSUPPORTED;
+	this->standard_partial_byte_output_encoding = LIBHASHSUM_UNSUPPORTED;
 	this->process = &process;
 	this->finalise_const = &finalise_const;
 	this->finalise = &finalise;
diff --git a/libhashsum_init_blake2s_hasher.c b/libhashsum_init_blake2s_hasher.c
index 689dc64..c2a2f37 100644
--- a/libhashsum_init_blake2s_hasher.c
+++ b/libhashsum_init_blake2s_hasher.c
@@ -167,6 +167,8 @@ libhashsum_init_blake2s_hasher(struct libhashsum_hasher *this, size_t hashbits,
 	this->hash_size = hashbits / 8U;
 	this->hash_output = NULL;
 	this->supports_non_whole_bytes = 0;
+	this->standard_partial_byte_input_encoding = LIBHASHSUM_UNSUPPORTED;
+	this->standard_partial_byte_output_encoding = LIBHASHSUM_UNSUPPORTED;
 	this->process = &process;
 	this->finalise_const = &finalise_const;
 	this->finalise = &finalise;
diff --git a/libhashsum_init_blake384_hasher.c b/libhashsum_init_blake384_hasher.c
index a64d5ee..f1f32dc 100644
--- a/libhashsum_init_blake384_hasher.c
+++ b/libhashsum_init_blake384_hasher.c
@@ -105,6 +105,8 @@ libhashsum_init_blake384_hasher(struct libhashsum_hasher *this, const void *salt
 	this->hash_size = LIBHASHSUM_BLAKE384_HASH_SIZE;
 	this->hash_output = NULL;
 	this->supports_non_whole_bytes = 1;
+	this->standard_partial_byte_input_encoding = LIBHASHSUM_MOST_SIGNIFICANT;
+	this->standard_partial_byte_output_encoding = LIBHASHSUM_UNSUPPORTED;
 	this->process = &process;
 	this->finalise_const = &finalise_const;
 	this->finalise = &finalise;
diff --git a/libhashsum_init_blake512_hasher.c b/libhashsum_init_blake512_hasher.c
index 6407a7b..d9e3aca 100644
--- a/libhashsum_init_blake512_hasher.c
+++ b/libhashsum_init_blake512_hasher.c
@@ -105,6 +105,8 @@ libhashsum_init_blake512_hasher(struct libhashsum_hasher *this, const void *salt
 	this->hash_size = LIBHASHSUM_BLAKE512_HASH_SIZE;
 	this->hash_output = NULL;
 	this->supports_non_whole_bytes = 1;
+	this->standard_partial_byte_input_encoding = LIBHASHSUM_MOST_SIGNIFICANT;
+	this->standard_partial_byte_output_encoding = LIBHASHSUM_UNSUPPORTED;
 	this->process = &process;
 	this->finalise_const = &finalise_const;
 	this->finalise = &finalise;
diff --git a/libhashsum_init_keccak__.c b/libhashsum_init_keccak__.c
index 9d58958..6e1abf7 100644
--- a/libhashsum_init_keccak__.c
+++ b/libhashsum_init_keccak__.c
@@ -149,6 +149,8 @@ libhashsum_init_keccak__(struct libhashsum_hasher *this, size_t hashbits, void *
 	this->hash_size += (size_t)!!(hashbits & 7U);
 	this->hash_output = NULL;
 	this->supports_non_whole_bytes = 1;
+	this->standard_partial_byte_input_encoding = LIBHASHSUM_LEAST_SIGNIFICANT;
+	this->standard_partial_byte_output_encoding = LIBHASHSUM_LEAST_SIGNIFICANT;
 	this->state.keccak.squeezes = squeezes;
 	this->state.keccak.suffix = suffix;
 
diff --git a/libhashsum_init_md2_hasher.c b/libhashsum_init_md2_hasher.c
index b28a6ae..a30ede8 100644
--- a/libhashsum_init_md2_hasher.c
+++ b/libhashsum_init_md2_hasher.c
@@ -139,6 +139,8 @@ libhashsum_init_md2_hasher(struct libhashsum_hasher *this)
 	this->hash_size = sizeof(this->state.md2.sum);
 	this->hash_output = NULL;
 	this->supports_non_whole_bytes = 0;
+	this->standard_partial_byte_input_encoding = LIBHASHSUM_UNSUPPORTED;
+	this->standard_partial_byte_output_encoding = LIBHASHSUM_UNSUPPORTED;
 	this->process = &process;
 	this->finalise_const = &finalise_const;
 	this->finalise = &finalise;
diff --git a/libhashsum_init_md4_hasher.c b/libhashsum_init_md4_hasher.c
index abcc115..2b6e607 100644
--- a/libhashsum_init_md4_hasher.c
+++ b/libhashsum_init_md4_hasher.c
@@ -184,6 +184,8 @@ libhashsum_init_md4_hasher(struct libhashsum_hasher *this)
 	this->hash_size = sizeof(this->state.md4.h.sum);
 	this->hash_output = NULL;
 	this->supports_non_whole_bytes = 1;
+	this->standard_partial_byte_input_encoding = LIBHASHSUM_MOST_SIGNIFICANT;
+	this->standard_partial_byte_output_encoding = LIBHASHSUM_UNSUPPORTED;
 	this->process = &process;
 	this->finalise_const = &finalise_const;
 	this->finalise = &finalise;
diff --git a/libhashsum_init_md5_hasher.c b/libhashsum_init_md5_hasher.c
index 7eec6ed..00cb81a 100644
--- a/libhashsum_init_md5_hasher.c
+++ b/libhashsum_init_md5_hasher.c
@@ -199,6 +199,8 @@ libhashsum_init_md5_hasher(struct libhashsum_hasher *this)
 	this->hash_size = sizeof(this->state.md5.h.sum);
 	this->hash_output = NULL;
 	this->supports_non_whole_bytes = 1;
+	this->standard_partial_byte_input_encoding = LIBHASHSUM_MOST_SIGNIFICANT;
+	this->standard_partial_byte_output_encoding = LIBHASHSUM_UNSUPPORTED;
 	this->process = &process;
 	this->finalise_const = &finalise_const;
 	this->finalise = &finalise;
diff --git a/libhashsum_init_ripemd_128_hasher.c b/libhashsum_init_ripemd_128_hasher.c
index 02ac338..2eb08da 100644
--- a/libhashsum_init_ripemd_128_hasher.c
+++ b/libhashsum_init_ripemd_128_hasher.c
@@ -220,6 +220,8 @@ libhashsum_init_ripemd_128_hasher(struct libhashsum_hasher *this)
 	this->hash_size = sizeof(this->state.ripemd_128.h.sum);
 	this->hash_output = NULL;
 	this->supports_non_whole_bytes = 1;
+	this->standard_partial_byte_input_encoding = LIBHASHSUM_MOST_SIGNIFICANT;
+	this->standard_partial_byte_output_encoding = LIBHASHSUM_UNSUPPORTED;
 	this->process = &process;
 	this->finalise_const = &finalise_const;
 	this->finalise = &finalise;
diff --git a/libhashsum_init_ripemd_160_hasher.c b/libhashsum_init_ripemd_160_hasher.c
index 2e510fa..86d3340 100644
--- a/libhashsum_init_ripemd_160_hasher.c
+++ b/libhashsum_init_ripemd_160_hasher.c
@@ -223,6 +223,8 @@ libhashsum_init_ripemd_160_hasher(struct libhashsum_hasher *this)
 	this->hash_size = sizeof(this->state.ripemd_160.h.sum);
 	this->hash_output = NULL;
 	this->supports_non_whole_bytes = 1;
+	this->standard_partial_byte_input_encoding = LIBHASHSUM_MOST_SIGNIFICANT;
+	this->standard_partial_byte_output_encoding = LIBHASHSUM_UNSUPPORTED;
 	this->process = &process;
 	this->finalise_const = &finalise_const;
 	this->finalise = &finalise;
diff --git a/libhashsum_init_ripemd_256_hasher.c b/libhashsum_init_ripemd_256_hasher.c
index d9249b4..316cc39 100644
--- a/libhashsum_init_ripemd_256_hasher.c
+++ b/libhashsum_init_ripemd_256_hasher.c
@@ -231,6 +231,8 @@ libhashsum_init_ripemd_256_hasher(struct libhashsum_hasher *this)
 	this->hash_size = sizeof(this->state.ripemd_256.h.sum);
 	this->hash_output = NULL;
 	this->supports_non_whole_bytes = 1;
+	this->standard_partial_byte_input_encoding = LIBHASHSUM_MOST_SIGNIFICANT;
+	this->standard_partial_byte_output_encoding = LIBHASHSUM_UNSUPPORTED;
 	this->process = &process;
 	this->finalise_const = &finalise_const;
 	this->finalise = &finalise;
diff --git a/libhashsum_init_ripemd_320_hasher.c b/libhashsum_init_ripemd_320_hasher.c
index 80e4e23..dad69a0 100644
--- a/libhashsum_init_ripemd_320_hasher.c
+++ b/libhashsum_init_ripemd_320_hasher.c
@@ -237,6 +237,8 @@ libhashsum_init_ripemd_320_hasher(struct libhashsum_hasher *this)
 	this->hash_size = sizeof(this->state.ripemd_320.h.sum);
 	this->hash_output = NULL;
 	this->supports_non_whole_bytes = 1;
+	this->standard_partial_byte_input_encoding = LIBHASHSUM_MOST_SIGNIFICANT;
+	this->standard_partial_byte_output_encoding = LIBHASHSUM_UNSUPPORTED;
 	this->process = &process;
 	this->finalise_const = &finalise_const;
 	this->finalise = &finalise;
diff --git a/libhashsum_init_sha0_hasher.c b/libhashsum_init_sha0_hasher.c
index b7d42a8..a860f77 100644
--- a/libhashsum_init_sha0_hasher.c
+++ b/libhashsum_init_sha0_hasher.c
@@ -65,6 +65,8 @@ libhashsum_init_sha0_hasher(struct libhashsum_hasher *this)
 	this->hash_size = sizeof(this->state.sha0.sum);
 	this->hash_output = NULL;
 	this->supports_non_whole_bytes = 1;
+	this->standard_partial_byte_input_encoding = LIBHASHSUM_LEAST_SIGNIFICANT;
+	this->standard_partial_byte_output_encoding = LIBHASHSUM_UNSUPPORTED;
 	this->process = &process;
 	this->finalise_const = &finalise_const;
 	this->finalise = &finalise;
diff --git a/libhashsum_init_sha1_hasher.c b/libhashsum_init_sha1_hasher.c
index 13020e2..bd514b3 100644
--- a/libhashsum_init_sha1_hasher.c
+++ b/libhashsum_init_sha1_hasher.c
@@ -65,6 +65,8 @@ libhashsum_init_sha1_hasher(struct libhashsum_hasher *this)
 	this->hash_size = sizeof(this->state.sha1.sum);
 	this->hash_output = NULL;
 	this->supports_non_whole_bytes = 1;
+	this->standard_partial_byte_input_encoding = LIBHASHSUM_LEAST_SIGNIFICANT;
+	this->standard_partial_byte_output_encoding = LIBHASHSUM_UNSUPPORTED;
 	this->process = &process;
 	this->finalise_const = &finalise_const;
 	this->finalise = &finalise;
diff --git a/libhashsum_init_sha2_hasher.c b/libhashsum_init_sha2_hasher.c
index 7e5aa38..ca455c3 100644
--- a/libhashsum_init_sha2_hasher.c
+++ b/libhashsum_init_sha2_hasher.c
@@ -94,6 +94,8 @@ libhashsum_init_sha2_hasher(struct libhashsum_hasher *this, unsigned algobits, s
 	this->hash_size = hashbits >> 3;
 	this->hash_output = NULL;
 	this->supports_non_whole_bytes = 1;
+	this->standard_partial_byte_input_encoding = LIBHASHSUM_LEAST_SIGNIFICANT;
+	this->standard_partial_byte_output_encoding = LIBHASHSUM_UNSUPPORTED;
 	this->process = &process;
 	this->finalise_const = &finalise_const;
 	this->finalise = &finalise;