diff --git a/asn1_decoder.cpp b/asn1_decoder.cpp
index ca4ee52..a9dfccc 100644
--- a/asn1_decoder.cpp
+++ b/asn1_decoder.cpp
@@ -14,178 +14,145 @@
  * limitations under the License.
  */
 
-#include <malloc.h>
-#include <stdint.h>
-#include <string.h>
-
 #include "asn1_decoder.h"
 
+#include <stdint.h>
 
-typedef struct asn1_context {
-  size_t length;
-  const uint8_t* p;
-  int app_type;
-} asn1_context_t;
-
-
-static const int kMaskConstructed = 0xE0;
-static const int kMaskTag = 0x7F;
-static const int kMaskAppType = 0x1F;
-
-static const int kTagOctetString = 0x04;
-static const int kTagOid = 0x06;
-static const int kTagSequence = 0x30;
-static const int kTagSet = 0x31;
-static const int kTagConstructed = 0xA0;
-
-asn1_context_t* asn1_context_new(const uint8_t* buffer, size_t length) {
-    asn1_context_t* ctx = (asn1_context_t*) calloc(1, sizeof(asn1_context_t));
-    if (ctx == NULL) {
-        return NULL;
-    }
-    ctx->p = buffer;
-    ctx->length = length;
-    return ctx;
+int asn1_context::peek_byte() const {
+  if (length_ <= 0) {
+    return -1;
+  }
+  return *p_;
 }
 
-void asn1_context_free(asn1_context_t* ctx) {
-    free(ctx);
+int asn1_context::get_byte() {
+  if (length_ <= 0) {
+    return -1;
+  }
+
+  int byte = *p_;
+  p_++;
+  length_--;
+  return byte;
 }
 
-static inline int peek_byte(asn1_context_t* ctx) {
-    if (ctx->length <= 0) {
-        return -1;
-    }
-    return *ctx->p;
+bool asn1_context::skip_bytes(size_t num_skip) {
+  if (length_ < num_skip) {
+    return false;
+  }
+  p_ += num_skip;
+  length_ -= num_skip;
+  return true;
 }
 
-static inline int get_byte(asn1_context_t* ctx) {
-    if (ctx->length <= 0) {
-        return -1;
-    }
-    int byte = *ctx->p;
-    ctx->p++;
-    ctx->length--;
-    return byte;
-}
-
-static inline bool skip_bytes(asn1_context_t* ctx, size_t num_skip) {
-    if (ctx->length < num_skip) {
-        return false;
-    }
-    ctx->p += num_skip;
-    ctx->length -= num_skip;
+bool asn1_context::decode_length(size_t* out_len) {
+  int num_octets = get_byte();
+  if (num_octets == -1) {
+    return false;
+  }
+  if ((num_octets & 0x80) == 0x00) {
+    *out_len = num_octets;
     return true;
-}
-
-static bool decode_length(asn1_context_t* ctx, size_t* out_len) {
-    int num_octets = get_byte(ctx);
-    if (num_octets == -1) {
-        return false;
+  }
+  num_octets &= kMaskTag;
+  if (static_cast<size_t>(num_octets) >= sizeof(size_t)) {
+    return false;
+  }
+  size_t length = 0;
+  for (int i = 0; i < num_octets; ++i) {
+    int byte = get_byte();
+    if (byte == -1) {
+      return false;
     }
-    if ((num_octets & 0x80) == 0x00) {
-        *out_len = num_octets;
-        return 1;
-    }
-    num_octets &= kMaskTag;
-    if ((size_t)num_octets >= sizeof(size_t)) {
-        return false;
-    }
-    size_t length = 0;
-    for (int i = 0; i < num_octets; ++i) {
-        int byte = get_byte(ctx);
-        if (byte == -1) {
-            return false;
-        }
-        length <<= 8;
-        length += byte;
-    }
-    *out_len = length;
-    return true;
+    length <<= 8;
+    length += byte;
+  }
+  *out_len = length;
+  return true;
 }
 
 /**
  * Returns the constructed type and advances the pointer. E.g. A0 -> 0
  */
-asn1_context_t* asn1_constructed_get(asn1_context_t* ctx) {
-    int type = get_byte(ctx);
-    if (type == -1 || (type & kMaskConstructed) != kTagConstructed) {
-        return NULL;
-    }
+asn1_context* asn1_context::asn1_constructed_get() {
+  int type = get_byte();
+  if (type == -1 || (type & kMaskConstructed) != kTagConstructed) {
+    return nullptr;
+  }
+  size_t length;
+  if (!decode_length(&length) || length > length_) {
+    return nullptr;
+  }
+  asn1_context* app_ctx = new asn1_context(p_, length);
+  app_ctx->app_type_ = type & kMaskAppType;
+  return app_ctx;
+}
+
+bool asn1_context::asn1_constructed_skip_all() {
+  int byte = peek_byte();
+  while (byte != -1 && (byte & kMaskConstructed) == kTagConstructed) {
+    skip_bytes(1);
     size_t length;
-    if (!decode_length(ctx, &length) || length > ctx->length) {
-        return NULL;
+    if (!decode_length(&length) || !skip_bytes(length)) {
+      return false;
     }
-    asn1_context_t* app_ctx = asn1_context_new(ctx->p, length);
-    app_ctx->app_type = type & kMaskAppType;
-    return app_ctx;
+    byte = peek_byte();
+  }
+  return byte != -1;
 }
 
-bool asn1_constructed_skip_all(asn1_context_t* ctx) {
-    int byte = peek_byte(ctx);
-    while (byte != -1 && (byte & kMaskConstructed) == kTagConstructed) {
-        skip_bytes(ctx, 1);
-        size_t length;
-        if (!decode_length(ctx, &length) || !skip_bytes(ctx, length)) {
-            return false;
-        }
-        byte = peek_byte(ctx);
-    }
-    return byte != -1;
+int asn1_context::asn1_constructed_type() const {
+  return app_type_;
 }
 
-int asn1_constructed_type(asn1_context_t* ctx) {
-    return ctx->app_type;
+asn1_context* asn1_context::asn1_sequence_get() {
+  if ((get_byte() & kMaskTag) != kTagSequence) {
+    return nullptr;
+  }
+  size_t length;
+  if (!decode_length(&length) || length > length_) {
+    return nullptr;
+  }
+  return new asn1_context(p_, length);
 }
 
-asn1_context_t* asn1_sequence_get(asn1_context_t* ctx) {
-    if ((get_byte(ctx) & kMaskTag) != kTagSequence) {
-        return NULL;
-    }
-    size_t length;
-    if (!decode_length(ctx, &length) || length > ctx->length) {
-        return NULL;
-    }
-    return asn1_context_new(ctx->p, length);
+asn1_context* asn1_context::asn1_set_get() {
+  if ((get_byte() & kMaskTag) != kTagSet) {
+    return nullptr;
+  }
+  size_t length;
+  if (!decode_length(&length) || length > length_) {
+    return nullptr;
+  }
+  return new asn1_context(p_, length);
 }
 
-asn1_context_t* asn1_set_get(asn1_context_t* ctx) {
-    if ((get_byte(ctx) & kMaskTag) != kTagSet) {
-        return NULL;
-    }
-    size_t length;
-    if (!decode_length(ctx, &length) || length > ctx->length) {
-        return NULL;
-    }
-    return asn1_context_new(ctx->p, length);
+bool asn1_context::asn1_sequence_next() {
+  size_t length;
+  if (get_byte() == -1 || !decode_length(&length) || !skip_bytes(length)) {
+    return false;
+  }
+  return true;
 }
 
-bool asn1_sequence_next(asn1_context_t* ctx) {
-    size_t length;
-    if (get_byte(ctx) == -1 || !decode_length(ctx, &length) || !skip_bytes(ctx, length)) {
-        return false;
-    }
-    return true;
+bool asn1_context::asn1_oid_get(const uint8_t** oid, size_t* length) {
+  if (get_byte() != kTagOid) {
+    return false;
+  }
+  if (!decode_length(length) || *length == 0 || *length > length_) {
+    return false;
+  }
+  *oid = p_;
+  return true;
 }
 
-bool asn1_oid_get(asn1_context_t* ctx, const uint8_t** oid, size_t* length) {
-    if (get_byte(ctx) != kTagOid) {
-        return false;
-    }
-    if (!decode_length(ctx, length) || *length == 0 || *length > ctx->length) {
-        return false;
-    }
-    *oid = ctx->p;
-    return true;
-}
-
-bool asn1_octet_string_get(asn1_context_t* ctx, const uint8_t** octet_string, size_t* length) {
-    if (get_byte(ctx) != kTagOctetString) {
-        return false;
-    }
-    if (!decode_length(ctx, length) || *length == 0 || *length > ctx->length) {
-        return false;
-    }
-    *octet_string = ctx->p;
-    return true;
+bool asn1_context::asn1_octet_string_get(const uint8_t** octet_string, size_t* length) {
+  if (get_byte() != kTagOctetString) {
+    return false;
+  }
+  if (!decode_length(length) || *length == 0 || *length > length_) {
+    return false;
+  }
+  *octet_string = p_;
+  return true;
 }