Refactor asn1_decoder functions into a class.
Test: mmma bootable/recovery
Test: recovery_unit_test passes.
Test: recovery_component_test passes.
Change-Id: If0bf25993158eaebeedff55ba4f4dd0f6e5f937d
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;
}