Merge pull request #27 from ERussel/improve/key-compression

add error handling for secp2561k1 public key uncompression
ERussel · Oct 13, 2021 · 4033eb8 · 4033eb8
2 parents b9df371 + 8158b32
commit 4033eb8
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Showing 4 changed files with 26 additions and 4 deletions.
diff --git a/IrohaCrypto.podspec b/IrohaCrypto.podspec
@@ -8,7 +8,7 @@
 
 Pod::Spec.new do |s|
   s.name             = 'IrohaCrypto'
-  s.version          = '0.8.2'
+  s.version          = '0.9.0'
   s.summary          = 'Provides object oriented wrappers for C/C++ crypto functions used by blockchains.'
 
   s.homepage         = 'https://github.com/soramitsu'

diff --git a/IrohaCrypto/Classes/secp256k1/SECPublicKey.h b/IrohaCrypto/Classes/secp256k1/SECPublicKey.h
@@ -14,6 +14,6 @@
 
 + (NSUInteger)uncompressedLength;
 
-- (nonnull NSData*)uncompressed;
+- (nullable NSData*)uncompressed:(NSError*_Nullable*_Nullable)error;
 
 @end
diff --git a/IrohaCrypto/Classes/secp256k1/SECPublicKey.m b/IrohaCrypto/Classes/secp256k1/SECPublicKey.m
@@ -7,6 +7,7 @@
 
 #import "SECPublicKey.h"
 #import <secp256k1/secp256k1.h>
+#import "IRCryptoKey.h"
 
 @interface SECPublicKey()
 
@@ -44,13 +45,26 @@ - (nullable instancetype)initWithRawData:(nonnull NSData*)data error:(NSError*_N
     return self;
 }
 
-- (nonnull NSData*)uncompressed {
+- (nullable NSData*)uncompressed:(NSError*_Nullable*_Nullable)error {
     secp256k1_pubkey rawPublicKey;
 
     secp256k1_context *context = secp256k1_context_create(SECP256K1_CONTEXT_NONE);
 
     int status = secp256k1_ec_pubkey_parse(context, &rawPublicKey, _rawData.bytes, [_rawData length]);
 
+    if (status == 0) {
+        secp256k1_context_destroy(context);
+
+        if (error) {
+            NSString *message = [NSString stringWithFormat:@"Uncompressing unexpectedly failed"];
+            *error = [NSError errorWithDomain:NSStringFromClass([self class])
+                                         code:IRCryptoKeyErrorInvalidRawData
+                                     userInfo:@{NSLocalizedDescriptionKey: message}];
+        }
+
+        return nil;
+    }
+
     size_t uncompressedLength = [SECPublicKey uncompressedLength];
     unsigned char uncompresedPubkey[uncompressedLength];
 
@@ -60,6 +74,8 @@ - (nonnull NSData*)uncompressed {
                                   &rawPublicKey,
                                   SECP256K1_EC_UNCOMPRESSED);
 
+    secp256k1_context_destroy(context);
+
     return [NSData dataWithBytes:uncompresedPubkey length:uncompressedLength];
 }
 

diff --git a/Tests/secp256k1/Secp256k1PublicKeyTests.m b/Tests/secp256k1/Secp256k1PublicKeyTests.m
@@ -42,7 +42,13 @@ - (void)testPublicKeyUncompression {
             return;
         }
 
-        NSData *actualUncompressed = [publicKey uncompressed];
+        NSData *actualUncompressed = [publicKey uncompressed:&error];
+
+        if (error) {
+            XCTFail(@"Did receive error: %@", [error localizedDescription]);
+            return;
+        }
+
         NSData *expectedUncompressed = [[NSData alloc] initWithHexString:UNCOMPRESSED[index] error:&error];
 
         if (error) {