snej@0: //
snej@0: //  MYPublicKey.m
snej@0: //  MYCrypto
snej@0: //
snej@0: //  Created by Jens Alfke on 3/21/09.
snej@0: //  Copyright 2009 Jens Alfke. All rights reserved.
snej@0: //
snej@0: 
snej@0: #import "MYPublicKey.h"
snej@0: #import "MYCrypto_Private.h"
snej@0: #import "MYDigest.h"
jens@21: #import "MYASN1Object.h"
jens@21: #import "MYDEREncoder.h"
jens@21: #import "MYBERParser.h"
snej@0: #import "MYErrorUtils.h"
snej@0: #import <CommonCrypto/CommonDigest.h>
snej@0: 
snej@0: 
jens@26: @interface MYPublicKey ()
jens@26: @property (retain) MYCertificate *certificate;
jens@26: @end
jens@26: 
jens@26: 
snej@0: #pragma mark -
snej@0: @implementation MYPublicKey
snej@0: 
snej@0: 
jens@21: - (id) initWithModulus: (NSData*)modulus exponent: (unsigned)exponent {
jens@21:     // An RSA key is encoded in ASN.1 as a sequence of modulus and exponent, both as integers.
jens@21:     MYASN1BigInteger *modulusInt = [[MYASN1BigInteger alloc] initWithUnsignedData: modulus];
jens@21:     id asn1 = $array( modulusInt, $object(exponent) );
jens@21:     [modulusInt release];
jens@21:     NSData *keyData = [MYDEREncoder encodeRootObject: asn1 error: nil];
jens@21:     return [self initWithKeyData: keyData];
jens@21: }
jens@21: 
snej@0: - (void) dealloc
snej@0: {
snej@0:     [_digest release];
snej@0:     [super dealloc];
snej@0: }
snej@0: 
jens@26: @synthesize certificate=_certificate;
jens@26: 
jens@23: - (SecExternalItemType) keyClass {
snej@3: #if MYCRYPTO_USE_IPHONE_API
snej@3:     return kSecAttrKeyClassPublic;
snej@3: #else
snej@0:     return kSecItemTypePublicKey;
snej@3: #endif
snej@0: }
snej@3: 
jens@23: #if MYCRYPTO_USE_IPHONE_API
jens@23: - (SecExternalItemType) keyType {
jens@23:     return kSecAttrKeyTypeRSA;
jens@23: }
jens@23: #endif
jens@23: 
snej@0: - (NSUInteger)hash {
snej@0:     return self.publicKeyDigest.hash;
snej@0: }
snej@0: 
snej@0: - (NSString*) description {
snej@0:     return $sprintf(@"%@[%@]", [self class], self.publicKeyDigest.abbreviatedHexString);
snej@0: }
snej@0: 
snej@0: - (MYSHA1Digest*) publicKeyDigest {
snej@0:     if (!_digest)
snej@3:         _digest = [[self _keyDigest] retain];
snej@0:     return _digest;
snej@0: }
snej@0: 
jens@26: #if MYCRYPTO_USE_IPHONE_API
jens@26: - (NSData*) keyData {
jens@26:     if (_certificate) {
jens@26:         return _certificate.info.subjectPublicKeyData;
jens@26:     } else {
jens@26:         return [super keyData];
jens@26:     }
jens@26: }
jens@26: #endif
jens@26: 
snej@3: #if !MYCRYPTO_USE_IPHONE_API
snej@13: - (SecExternalFormat) _externalFormat {
snej@14:     return kSecFormatBSAFE;
snej@0: }
snej@3: #endif
snej@0: 
snej@0: 
jens@21: - (BOOL) getModulus: (NSData**)outModulus exponent: (unsigned*)outExponent {
jens@21:     Assert(outModulus!=nil);
jens@21:     Assert(outExponent!=nil);
jens@21:     NSArray *asn1 = $castIf(NSArray, MYBERParse(self.keyData, nil));
jens@21:     if (!asn1 || asn1.count != 2)
jens@21:         return NO;
jens@21:     *outModulus = $castIf(MYASN1BigInteger, [asn1 objectAtIndex: 0]).unsignedData;
jens@21:     *outExponent = $castIf(NSNumber, [asn1 objectAtIndex: 1]).unsignedIntValue;
jens@21:     return (*outModulus!=nil && *outExponent>=3);
jens@21: }
jens@21: 
jens@21: 
snej@13: - (NSData*) rawEncryptData: (NSData*)data {
snej@3:     return [self _crypt: data operation: YES];
snej@0: }
snej@0: 
snej@0: 
snej@0: - (BOOL) verifySignature: (NSData*)signature ofData: (NSData*)data {
snej@0:     Assert(data);
snej@0:     Assert(signature);
snej@1:     
snej@3: #if MYCRYPTO_USE_IPHONE_API
snej@3:     uint8_t digest[CC_SHA1_DIGEST_LENGTH];
snej@3:     CC_SHA1(data.bytes,data.length, digest);
snej@3:     OSStatus err = SecKeyRawVerify(self.keyRef, kSecPaddingPKCS1SHA1,
snej@3:                                    digest,sizeof(digest), //data.bytes, data.length,
snej@3:                                    signature.bytes, signature.length);
snej@3:     return err==noErr;
snej@3:     
snej@3: #else
jens@17:     CSSM_CC_HANDLE ccHandle = [self _createSignatureContext: CSSM_ALGID_SHA1WithRSA];
snej@0:     if (!ccHandle) return NO;
snej@0:     CSSM_DATA original = {data.length, (void*)data.bytes};
snej@0:     CSSM_DATA sig = {signature.length, (void*)signature.bytes};
snej@0:     CSSM_RETURN cssmErr = CSSM_VerifyData(ccHandle, &original, 1, CSSM_ALGID_NONE, &sig);
snej@0:     CSSM_DeleteContext(ccHandle);
snej@0:     if (cssmErr == CSSM_OK)
snej@0:         return YES;
snej@0:     if (cssmErr != CSSMERR_CSP_VERIFY_FAILED)
snej@0:         Warn(@"CSSM error verifying signature: %u", MYErrorName(MYCSSMErrorDomain,cssmErr));
snej@0:     return NO;
snej@3: #endif
snej@0: }
snej@0: 
snej@0: 
snej@4: #if !TARGET_OS_IPHONE
snej@4: - (CSSM_WRAP_KEY*) _unwrappedCSSMKey {
snej@4:     const CSSM_KEY *key = self.cssmKey;
snej@4:     
snej@4:     if (key->KeyHeader.BlobType == CSSM_KEYBLOB_WRAPPED) {
snej@4:         Warn(@"Key is already wrapped.\n");
snej@4:         return NULL;
snej@4:     }
snej@4:     
snej@4:     if (key->KeyHeader.KeyClass != CSSM_KEYCLASS_PUBLIC_KEY)
snej@4:         Warn(@"Warning: Null wrapping a non-public key - this is a dangerous operation.\n");
snej@4:     
snej@4:     const CSSM_ACCESS_CREDENTIALS* credentials;
snej@4:     credentials = [self cssmCredentialsForOperation: CSSM_ACL_AUTHORIZATION_EXPORT_WRAPPED
snej@4:                                                type: kSecCredentialTypeDefault error: nil];
snej@4:     CSSM_CC_HANDLE ccHandle;
snej@4:     if (!checkcssm(CSSM_CSP_CreateSymmetricContext(self.cssmCSPHandle, 
snej@4:                                                    CSSM_ALGID_NONE, CSSM_ALGMODE_WRAP, 
snej@4:                                                    NULL, NULL, NULL, 
snej@4:                                                    CSSM_PADDING_NONE, NULL, 
snej@4:                                                    &ccHandle),
snej@4:                    @"CSSM_CSP_CreateSymmetricContext"))
snej@4:         return NULL;
snej@4:                    
snej@4:     CSSM_WRAP_KEY *result = malloc(sizeof(CSSM_WRAP_KEY));
snej@4:     if (!checkcssm(CSSM_WrapKey(ccHandle, credentials, key, NULL, result),
snej@4:                       @"CSSM_WrapKey")) {
snej@4:         free(result);
snej@4:         result = NULL;
snej@4:     }
snej@4:     CSSM_DeleteContext(ccHandle);
snej@4:     return result;
snej@4: }
snej@13: 
snej@13: 
snej@13: - (NSData*) wrapSessionKey: (MYSymmetricKey*)sessionKey {
snej@13:     const CSSM_ACCESS_CREDENTIALS* credentials;
snej@13:     credentials = [self cssmCredentialsForOperation: CSSM_ACL_AUTHORIZATION_EXPORT_WRAPPED
snej@13:                                                type: kSecCredentialTypeDefault error: nil];
snej@13:     CSSM_CSP_HANDLE cspHandle = self.cssmCSPHandle;
snej@13:     CSSM_CC_HANDLE ctx;
snej@13:     if (!checkcssm(CSSM_CSP_CreateAsymmetricContext(cspHandle,
snej@13:                                                     self.cssmAlgorithm,
snej@13:                                                     credentials, 
snej@13:                                                     self.cssmKey,
snej@13:                                                     CSSM_PADDING_PKCS1,
snej@13:                                                     &ctx), 
snej@13:                    @"CSSM_CSP_CreateAsymmetricContext"))
snej@13:         return nil;
snej@14:         
snej@13:     // Now wrap the key:
snej@13:     NSData *result = nil;
snej@13:     CSSM_WRAP_KEY wrappedKey = {};
snej@14:     CSSM_DATA descriptiveData = {};
snej@14:     if (checkcssm(CSSM_WrapKey(ctx, credentials, sessionKey.cssmKey, &descriptiveData, &wrappedKey),
snej@13:                   @"CSSM_WrapKey")) {
snej@13:         // ...and copy the wrapped key data to the result NSData:
snej@13:         result = [NSData dataWithBytes: wrappedKey.KeyData.Data length: wrappedKey.KeyData.Length];
snej@13:         CSSM_FreeKey(cspHandle, credentials, &wrappedKey, NO);
snej@13:     }
snej@13:     // Finally, delete the context
snej@13:     CSSM_DeleteContext(ctx);
snej@13:     return result;
snej@13: }
snej@13: 
snej@13: 
snej@4: #endif
snej@4: 
snej@4: 
snej@0: @end
snej@0: 
snej@0: 
snej@0: 
snej@0: /*
snej@0:  Copyright (c) 2009, Jens Alfke <jens@mooseyard.com>. All rights reserved.
snej@0:  
snej@0:  Redistribution and use in source and binary forms, with or without modification, are permitted
snej@0:  provided that the following conditions are met:
snej@0:  
snej@0:  * Redistributions of source code must retain the above copyright notice, this list of conditions
snej@0:  and the following disclaimer.
snej@0:  * Redistributions in binary form must reproduce the above copyright notice, this list of conditions
snej@0:  and the following disclaimer in the documentation and/or other materials provided with the
snej@0:  distribution.
snej@0:  
snej@0:  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
snej@0:  IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 
snej@0:  FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRI-
snej@0:  BUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
snej@0:  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 
snej@0:   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
snej@0:  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 
snej@0:  THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
snej@0:  */