Add OCaml binding for RNG and hash functions. Add hex_encode to FFI

2 files changed, 69 insertions, 0 deletions

diff --git a/src/lib/ffi/ffi.cpp b/src/lib/ffi/ffi.cpp
index 2151c33a9..4fcdb63c1 100644
--- a/src/lib/ffi/ffi.cpp
+++ b/src/lib/ffi/ffi.cpp
@@ -15,6 +15,7 @@
 #include <botan/version.h>
 #include <botan/pubkey.h>
 #include <botan/data_src.h>
+#include <botan/hex.h>
 #include <botan/mem_ops.h>
 #include <cstring>
 #include <memory>
@@ -177,6 +178,27 @@ uint32_t botan_version_minor() { return Botan::version_minor(); }
 uint32_t botan_version_patch() { return Botan::version_patch(); }
 uint32_t botan_version_datestamp()  { return Botan::version_datestamp(); }
 
+int botan_same_mem(const uint8_t* x, const uint8_t* y, size_t len)
+   {
+   return Botan::same_mem(x, y, len) ? 0 : 1;
+   }
+
+int botan_hex_encode(const uint8_t* in, size_t len, char* out, uint32_t flags)
+   {
+   try
+      {
+      const bool uppercase = (flags & BOTAN_FFI_HEX_LOWER_CASE) == 0;
+      Botan::hex_encode(out, in, len, uppercase);
+      return 0;
+      }
+   catch(std::exception& e)
+      {
+      log_exception(BOTAN_CURRENT_FUNCTION, e.what());
+      }
+
+   return 1;
+   }
+
 int botan_rng_init(botan_rng_t* rng_out, const char* rng_type)
    {
    // Just gives unique_ptr something to delete, really
diff --git a/src/lib/ffi/ffi.h b/src/lib/ffi/ffi.h
index ca92977f4..a516529b4 100644
--- a/src/lib/ffi/ffi.h
+++ b/src/lib/ffi/ffi.h
@@ -50,12 +50,23 @@ BOTAN_DLL uint32_t botan_version_datestamp();
 */
 BOTAN_DLL int botan_same_mem(const uint8_t* x, const uint8_t* y, size_t len);
 
+#define BOTAN_FFI_HEX_LOWER_CASE 1
+
+BOTAN_DLL int botan_hex_encode(const uint8_t* x, size_t len, char* out, uint32_t flags);
+
 /*
 * RNG
 */
 typedef struct botan_rng_struct* botan_rng_t;
 
+/**
+* TODO: replace rng_type with simple flags? 
+*/
 BOTAN_DLL int botan_rng_init(botan_rng_t* rng, const char* rng_type);
+
+/**
+* TODO: better name
+*/
 BOTAN_DLL int botan_rng_get(botan_rng_t rng, uint8_t* out, size_t out_len);
 BOTAN_DLL int botan_rng_reseed(botan_rng_t rng, size_t bits);
 BOTAN_DLL int botan_rng_destroy(botan_rng_t rng);
@@ -65,13 +76,49 @@ BOTAN_DLL int botan_rng_destroy(botan_rng_t rng);
 */
 typedef struct botan_hash_struct* botan_hash_t;
 
+/**
+* Initialize a hash object:
+*   botan_hash_t hash
+*   botan_hash_init(&hash, "SHA-384", 0);
+*
+* Flags should be 0 in current API revision, all other uses are reserved.
+*  and return BOTAN_FFI_ERROR_BAD_FLAG.
+
+* TODO: since output_length is effectively required to use this API,
+* return it from init as an output parameter
+*/
 BOTAN_DLL int botan_hash_init(botan_hash_t* hash, const char* hash_name, uint32_t flags);
+
+/**
+* Writes the output length of the hash object to *output_length
+*/
 BOTAN_DLL int botan_hash_output_length(botan_hash_t hash, size_t* output_length);
+
+/**
+* Send more input to the hash function.
+*/
 BOTAN_DLL int botan_hash_update(botan_hash_t hash, const uint8_t* in, size_t in_len);
+
+/**
+* Finalizes the hash computation and writes the output to
+* out[0:botan_hash_output_length()] then reinitializes for computing
+* another digest as if botan_hash_clear had been called.
+*/
 BOTAN_DLL int botan_hash_final(botan_hash_t hash, uint8_t out[]);
+
+/**
+* Reinitializes the state of the hash computation. A hash can
+* be computed (with update/final) immediately.
+*/
 BOTAN_DLL int botan_hash_clear(botan_hash_t hash);
+
+/**
+* Frees all resources of this object
+*/
 BOTAN_DLL int botan_hash_destroy(botan_hash_t hash);
 
+BOTAN_DLL int botan_hash_name(botan_hash_t hash, char* name, size_t name_len);
+
 /*
 * Message Authentication
 */