/* * Copyright (c) 2000-2001 Apple Computer, Inc. All Rights Reserved. * * The contents of this file constitute Original Code as defined in and are * subject to the Apple Public Source License Version 1.2 (the 'License'). * You may not use this file except in compliance with the License. Please obtain * a copy of the License at http://www.apple.com/publicsource and read it before * using this file. * * This Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS * OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, INCLUDING WITHOUT * LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR * PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see the License for the * specific language governing rights and limitations under the License. */ /* * Session_Crypto.cpp: CL session functions: sign, verify, CSSM_KEY extraction. * * Created 9/1/2000 by Doug Mitchell. * Copyright (c) 2000 by Apple Computer. */ #include "AppleX509CLSession.h" #include "DecodedCert.h" #include "SnaccUtils.h" #include "cldebugging.h" #include "CSPAttacher.h" #include "CertBuilder.h" #include #include #include #include /* * Given a DER-encoded cert, obtain a fully usable CSSM_KEY representing * the cert's public key. */ void AppleX509CLSession::CertGetKeyInfo( const CssmData &Cert, CSSM_KEY_PTR &Key) { DecodedCert decodedCert(*this, Cert); Key = decodedCert.extractCSSMKey(*this); } /* * Given a DER-encoded cert and a fully specified crypto context, verify * cert's TBS and signature. */ void AppleX509CLSession::CertVerifyWithKey( CSSM_CC_HANDLE CCHandle, const CssmData &CertToBeVerified) { CssmAutoData tbs(*this); CssmAutoData algId(*this); CssmAutoData sig(*this); CL_certDecodeComponents(CertToBeVerified, tbs, algId, sig); verifyData(CCHandle, tbs, sig); } /* * Verify a DER-encoded cert, obtaining crypto context from either * caller-specified context or by inference from SignerCert. */ void AppleX509CLSession::CertVerify( CSSM_CC_HANDLE CCHandle, const CssmData &CertToBeVerified, const CssmData *SignerCert, const CSSM_FIELD *VerifyScope, uint32 ScopeSize) { if((VerifyScope != NULL) || (ScopeSize != 0)) { CssmError::throwMe(CSSMERR_CL_SCOPE_NOT_SUPPORTED); } if((CCHandle == CSSM_INVALID_HANDLE) && (SignerCert == NULL)) { /* need one or the other */ CssmError::throwMe(CSSMERR_CL_INVALID_CONTEXT_HANDLE); } /* get top-level components */ CssmAutoData tbs(*this); // in DER format CssmAutoData algId(*this); // in DER format CssmAutoData sig(*this); // in DER format CL_certDecodeComponents(CertToBeVerified, tbs, algId, sig); /* these must be explicitly freed upon exit */ CSSM_KEY_PTR signerPubKey = NULL; CSSM_CONTEXT_PTR context = NULL; CSSM_CSP_HANDLE cspHand = CSSM_INVALID_HANDLE; CSSM_CC_HANDLE ourCcHand = CSSM_INVALID_HANDLE; /* SignerCert optional; if present, obtain its subject key */ if(SignerCert != NULL) { CertGetKeyInfo(*SignerCert, signerPubKey); } /* signerPubKey must be explicitly freed in any case */ try { if(CCHandle != CSSM_INVALID_HANDLE) { /* * We'll use this CCHandle for the sig verify, but * make sure it matches possible incoming SignerCert parameters */ if(SignerCert != NULL) { CSSM_RETURN crtn; /* extract signer's public key as a CSSM_KEY from context */ crtn = CSSM_GetContext(CCHandle, &context); if(crtn) { CssmError::throwMe(CSSMERR_CL_INVALID_CONTEXT_HANDLE); } CSSM_CONTEXT_ATTRIBUTE_PTR attr; crtn = CSSM_GetContextAttribute(context, CSSM_ATTRIBUTE_KEY, &attr); if(crtn) { errorLog0("CertVerify: valid CCHandle but no key!\n"); CssmError::throwMe(CSSMERR_CL_INVALID_CONTEXT_HANDLE); } /* require match */ CASSERT(signerPubKey != NULL); CSSM_KEY_PTR contextPubKey = attr->Attribute.Key; if(contextPubKey->KeyHeader.AlgorithmId != signerPubKey->KeyHeader.AlgorithmId) { errorLog0("CertVerify: AlgorithmId mismatch!\n"); CssmError::throwMe(CSSMERR_CL_INVALID_CONTEXT_HANDLE); } /* TBD - check key size, when we have a CSP which can report it */ /* TBD - anything else? */ } /* verifying multiple contexts */ /* OK to use CCHandle as is for verify context */ } /* valid CCHandle */ else { /* * All we have is signer cert. We already have its public key; * get signature alg from CertToBeVerified's Cert.algID (which * we currently have in DER form). */ CASSERT(SignerCert != NULL); CASSERT(signerPubKey != NULL); AlgorithmIdentifier snaccAlgId; //CL_decodeAlgId(algId, snaccAlgId); SC_decodeAsnObj(algId, snaccAlgId); CSSM_ALGORITHMS vfyAlg = CL_snaccOidToCssmAlg(snaccAlgId.algorithm); /* attach to CSP, cook up a context */ cspHand = getGlobalCspHand(true); CSSM_RETURN crtn; crtn = CSSM_CSP_CreateSignatureContext(cspHand, vfyAlg, NULL, // Access Creds signerPubKey, &ourCcHand); CCHandle = ourCcHand; } /* inferring sig verify context from SignerCert */ verifyData(CCHandle, tbs, sig); } catch(...) { /* FIXME - isn't there a better way to do this? Save the * exception as a CSSM_RETURN and throw it if nonzero later? */ if(context != NULL) { CSSM_FreeContext(context); } CL_freeCSSMKey(signerPubKey, *this); if(ourCcHand != CSSM_INVALID_HANDLE) { CSSM_DeleteContext(ourCcHand); } throw; } if(context != NULL) { CSSM_FreeContext(context); } CL_freeCSSMKey(signerPubKey, *this); if(ourCcHand != CSSM_INVALID_HANDLE) { CSSM_DeleteContext(ourCcHand); } } /* * Given a DER-encoded TBSCert and a fully specified crypto context, * sign the TBSCert and return the resulting DER-encoded Cert. */ void AppleX509CLSession::CertSign( CSSM_CC_HANDLE CCHandle, const CssmData &CertTemplate, const CSSM_FIELD *SignScope, uint32 ScopeSize, CssmData &SignedCert) { if((SignScope != NULL) || (ScopeSize != 0)) { CssmError::throwMe(CSSMERR_CL_SCOPE_NOT_SUPPORTED); } if(CCHandle == CSSM_INVALID_HANDLE) { CssmError::throwMe(CSSMERR_CL_INVALID_CONTEXT_HANDLE); } /* cook up algId from context->(signing key, sig algorithm) */ CSSM_CONTEXT_PTR context = NULL; // must be freed CSSM_RETURN crtn; crtn = CSSM_GetContext(CCHandle, &context); if(crtn) { CssmError::throwMe(CSSMERR_CL_INVALID_CONTEXT_HANDLE); } CSSM_CONTEXT_ATTRIBUTE_PTR attr; // not freed crtn = CSSM_GetContextAttribute(context, CSSM_ATTRIBUTE_KEY, &attr); if(crtn) { errorLog0("CertSign: valid CCHandle but no signing key!\n"); CssmError::throwMe(CSSMERR_CL_INVALID_CONTEXT_HANDLE); } CSSM_KEY_PTR signingKey = attr->Attribute.Key; if(signingKey == NULL) { errorLog0("CertSign: valid CCHandle, NULL signing key!\n"); CssmError::throwMe(CSSMERR_CL_INVALID_CONTEXT_HANDLE); } AlgorithmIdentifier snaccAlgId; CssmAutoData encAlgId(*this); CssmAutoData rawSig(*this); CssmAutoData fullCert(*this); try { /* CSSM alg --> snacc-style AlgorithmIdentifier object */ CL_cssmAlgToSnaccOid(context->AlgorithmType, snaccAlgId.algorithm); /* NULL params - FIXME - is this OK? */ CL_nullAlgParams(snaccAlgId); /* DER-encode the algID */ SC_encodeAsnObj(snaccAlgId, encAlgId, 128); /* sign TBS --> sig */ signData(CCHandle, CertTemplate, rawSig); /* put it all together */ CL_certEncodeComponents(CertTemplate, encAlgId, rawSig, fullCert); } catch (...) { CSSM_FreeContext(context); throw; } CSSM_FreeContext(context); SignedCert = fullCert.release(); } /*** Private functions ***/ /* * Sign a CssmData with the specified signing context. Used for * signing both certs and CRLs; this routine doesn't know anything * about either one. */ void AppleX509CLSession::signData( CSSM_CC_HANDLE ccHand, const CssmData &tbs, CssmOwnedData &sig) // mallocd and returned { CSSM_RETURN crtn; CssmData cSig; crtn = CSSM_SignData( ccHand, &tbs, 1, // DataBufCount CSSM_ALGID_NONE, // DigestAlgorithm, &cSig); if(crtn) { errorLog1("AppleX509CLSession::CSSM_SignData: %s\n", cssmErrorString(crtn).c_str()); CssmError::throwMe(crtn); } sig.set(cSig); } /* * Verify a block of data given a crypto context and a signature. * Used for verifying certs and CRLs. Returns a CSSM_RETURN (callers * always need to clean up after calling us). */ void AppleX509CLSession::verifyData( CSSM_CC_HANDLE ccHand, const CssmData &tbs, const CssmData &sig) { CSSM_RETURN crtn; crtn = CSSM_VerifyData(ccHand, &tbs, 1, CSSM_ALGID_NONE, // Digest alg &sig); if(crtn) { // errorLog1("AppleX509CLSession::verifyData: %s\n", // cssmErrorString(crtn).c_str()); if(crtn == CSSMERR_CSP_VERIFY_FAILED) { /* CSP and CL report this differently */ CssmError::throwMe(CSSMERR_CL_VERIFICATION_FAILURE); } else { CssmError::throwMe(crtn); } } }