1 files changed, 138 insertions, 0 deletions
diff --git a/lib/crypto.c b/lib/crypto.c
new file mode 100644
index 0000000..1cc9a99
--- /dev/null
+++ b/lib/crypto.c
@@ -0,0 +1,138 @@
+#include <stdint.h>
+//#include <stdio.h>
+//#include <unistd.h>
+#include <errno.h>
+#include <alloca.h>
+
+#include <ucode/module.h>
+
+#include <mbedtls/error.h>
+#include <mbedtls/md.h>
+#include <mbedtls/pk.h>
+
+#define TRUE ucv_boolean_new(true)
+#define FALSE ucv_boolean_new(false)
+
+static uc_resource_type_t *pk_type;
+
+static uc_value_t *
+md_digest(uc_vm_t *vm, size_t nargs)
+{
+	uc_value_t *alg = uc_fn_arg(0);
+	uc_value_t *input = uc_fn_arg(1);
+
+	if (ucv_type(alg) != UC_STRING)
+		uc_vm_raise_exception(vm, EXCEPTION_TYPE, "alg not a string");
+
+	if (ucv_type(input) != UC_STRING)
+		uc_vm_raise_exception(vm, EXCEPTION_TYPE, "input not a string");
+
+	const mbedtls_md_info_t *info = mbedtls_md_info_from_string(ucv_string_get(alg));
+
+	if (!info)
+		uc_vm_raise_exception(vm, EXCEPTION_TYPE, "unknown MD algorithm");
+
+	unsigned char size = mbedtls_md_get_size(info);
+	char *output = alloca(size);
+
+	if (mbedtls_md(info, (const unsigned char*)ucv_string_get(input), ucv_string_length(input), (unsigned char*)output))
+		uc_vm_raise_exception(vm, EXCEPTION_RUNTIME, "bad input data");
+
+	uc_value_t *rv = ucv_string_new_length(output, size);
+	return rv;
+}
+
+static uc_value_t *
+pk_init(uc_vm_t *vm, size_t nargs)
+{
+	mbedtls_pk_context *ctx = malloc(sizeof(mbedtls_pk_context));
+
+	mbedtls_pk_init(ctx);
+	return uc_resource_new(pk_type, ctx);
+}
+
+static void
+pk_free(void *ptr)
+{
+	mbedtls_pk_context *ctx = ptr;
+
+	mbedtls_pk_free(ctx);
+	free(ctx);
+}
+
+static uc_value_t *
+pk_set_public_key(uc_vm_t *vm, size_t nargs)
+{
+	mbedtls_pk_context *ctx = uc_fn_thisval("mbedtls.pk");
+
+        if (!ctx)
+		uc_vm_raise_exception(vm, EXCEPTION_TYPE, "invalid mbedtls.pk object");
+
+	uc_value_t *key = uc_fn_arg(0);
+
+	if (ucv_type(key) != UC_STRING)
+		uc_vm_raise_exception(vm, EXCEPTION_TYPE, "key is not a string");
+
+	int err = mbedtls_pk_parse_public_key(ctx, (const unsigned char*)ucv_string_get(key), ucv_string_length(key));
+	if (err)
+		uc_vm_raise_exception(vm, EXCEPTION_RUNTIME, "not a valid PEM/DER key %s: %s",
+				      mbedtls_high_level_strerr(err),
+				      mbedtls_low_level_strerr(err));
+	return NULL;
+}
+
+static uc_value_t *
+pk_verify(uc_vm_t *vm, size_t nargs)
+{
+	mbedtls_pk_context *ctx = uc_fn_thisval("mbedtls.pk");
+
+        if (!ctx)
+		uc_vm_raise_exception(vm, EXCEPTION_TYPE, "invalid mbedtls.pk object");
+
+	uc_value_t *md_alg = uc_fn_arg(0);
+	uc_value_t *hash = uc_fn_arg(1);
+	uc_value_t *sig = uc_fn_arg(2);
+
+	if (ucv_type(md_alg) != UC_STRING)
+		uc_vm_raise_exception(vm, EXCEPTION_TYPE, "md_alg is not a string");
+
+	if (ucv_type(hash) != UC_STRING)
+		uc_vm_raise_exception(vm, EXCEPTION_TYPE, "hash is not a string");
+
+	if (ucv_type(sig) != UC_STRING)
+		uc_vm_raise_exception(vm, EXCEPTION_TYPE, "sig is not a string");
+
+	const mbedtls_md_info_t *md_info = mbedtls_md_info_from_string(ucv_string_get(md_alg));
+
+	if (!md_info)
+		uc_vm_raise_exception(vm, EXCEPTION_TYPE, "unknown MD algorithm");
+
+	const mbedtls_md_type_t md_type = mbedtls_md_get_type(md_info);
+
+	int err = mbedtls_pk_verify(ctx, md_type,
+				    (const unsigned char*)ucv_string_get(hash), ucv_string_length(hash),
+				    (const unsigned char*)ucv_string_get(sig), ucv_string_length(sig));
+	if (err)
+		uc_vm_raise_exception(vm, EXCEPTION_RUNTIME, "validation failed: %s: %s",
+				      mbedtls_high_level_strerr(err),
+				      mbedtls_low_level_strerr(err));
+
+	return TRUE;
+}
+
+static const uc_function_list_t global_fns[] = {
+	{ "md_digest",			md_digest },
+	{ "pk",				pk_init },
+};
+
+static const uc_function_list_t pk_fns[] = {
+	{ "set_public_key",		pk_set_public_key },
+	{ "verify",			pk_verify },
+};
+
+void uc_module_init(uc_vm_t *vm, uc_value_t *scope)
+{
+	uc_function_list_register(scope, global_fns);
+
+	pk_type = uc_type_declare(vm, "mbedtls.pk", pk_fns, pk_free);
+}