--- /dev/null
+/*
+ * Copyright (c) 2003 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.
+ */
+/*
+ * pkcs12Derive.cpp - PKCS12 PBE routine
+ *
+ * Created 2/28/03 by Doug Mitchell.
+ */
+
+#include <Security/cssmapple.h>
+#include <openssl/bn.h>
+#include <pbkdDigest.h>
+
+#include "pkcs12Derive.h"
+#include "AppleCSPUtils.h"
+#include "AppleCSPContext.h"
+
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <assert.h>
+#include <security_asn1/SecNssCoder.h>
+
+#include <CoreFoundation/CoreFoundation.h>
+
+/* specify which flavor of bits to generate */
+typedef enum {
+ PBE_ID_Key = 1,
+ PBE_ID_IV = 2,
+ PBE_ID_MAC = 3
+} P12_PBE_ID;
+
+/*
+ * Create a "string" (in the loose p12 notation) of specified length
+ * from the concatention of copies of the specified input string.
+ */
+static unsigned char *p12StrCat(
+ const unsigned char *inStr,
+ unsigned inStrLen,
+ SecNssCoder &coder,
+ unsigned outLen,
+ unsigned char *outStr = NULL) // if not present, we malloc
+{
+ if(outStr == NULL) {
+ outStr = (unsigned char *)coder.malloc(outLen);
+ }
+ unsigned toMove = outLen;
+ unsigned char *outp = outStr;
+ while(toMove) {
+ unsigned thisMove = inStrLen;
+ if(thisMove > toMove) {
+ thisMove = toMove;
+ }
+ memmove(outp, inStr, thisMove);
+ toMove -= thisMove;
+ outp += thisMove;
+ }
+ return outStr;
+}
+
+/*
+ * PBE generator per PKCS12 v.1 section B.2.
+ */
+static CSSM_RETURN p12PbeGen(
+ const CSSM_DATA &pwd, // unicode, double null terminated
+ const uint8 *salt,
+ unsigned saltLen,
+ unsigned iterCount,
+ P12_PBE_ID pbeId,
+ CSSM_ALGORITHMS hashAlg, // MS5 or SHA1 only
+ SecNssCoder &coder, // for temp allocs
+ /* result goes here, mallocd by caller */
+ uint8 *outbuf,
+ unsigned outbufLen)
+{
+ CSSM_RETURN ourRtn = CSSM_OK;
+ unsigned unipassLen = pwd.Length;
+ unsigned char *unipass = pwd.Data;
+ int irtn;
+
+ /*
+ * all variables of the form p12_<XXX> represent <XXX> from the
+ * PKCS12 spec. E.g., p12_u is u, the length of the digest output.
+ * Only difference here is: all of our sizes are in BYTES, not
+ * bits.
+ */
+ unsigned p12_r = iterCount;
+ unsigned p12_n = outbufLen;
+
+ unsigned p12_u; // hash output size
+ unsigned p12_v; // hash block size
+ unsigned char *p12_P = NULL; // catted passwords
+ unsigned char *p12_S = NULL; // catted salts
+
+ switch(hashAlg) {
+ case CSSM_ALGID_MD5:
+ p12_u = kMD5DigestSize;
+ p12_v = kMD5BlockSize;
+ break;
+ case CSSM_ALGID_SHA1:
+ p12_u = kSHA1DigestSize;
+ p12_v = kSHA1BlockSize;
+ break;
+ default:
+ return CSSMERR_CSP_INVALID_ALGORITHM;
+ }
+
+ /*
+ * 1. Construct a string, D (the diversifier), by
+ * concatenating v/8 copies of ID.
+ */
+ unsigned char *p12_D = NULL; // diversifier
+ p12_D = (unsigned char *)coder.malloc(p12_v);
+ for(unsigned dex=0; dex<p12_v; dex++) {
+ p12_D[dex] = (unsigned char)pbeId;
+ }
+
+ /*
+ * 2. Concatenate copies of the salt together to create
+ * a string S of length v * ceil(s/v) bits (the final copy
+ * of the salt may be truncated to create S). Note that if
+ * the salt is the empty string, then so is S.
+ */
+ unsigned p12_Slen = p12_v * ((saltLen + p12_v - 1) / p12_v);
+ if(p12_Slen) {
+ p12_S = p12StrCat(salt, saltLen, coder, p12_Slen);
+ }
+
+
+ /*
+ * 3. Concatenate copies of the password together to create
+ * a string P of length v * ceil(p/v) bits (the final copy of
+ * the password may be truncated to create P). Note that
+ * if the password is the empty string, then so is P.
+ */
+ unsigned p12_Plen = p12_v * ((unipassLen + p12_v - 1) / p12_v);
+ if(p12_Plen) {
+ p12_P = p12StrCat(unipass, unipassLen, coder, p12_Plen);
+ }
+
+ /*
+ * 4. Set I= S||P to be the concatenation of S and P.
+ */
+ unsigned char *p12_I =
+ (unsigned char *)coder.malloc(p12_Slen + p12_Plen);
+ memmove(p12_I, p12_S, p12_Slen);
+ if(p12_Plen) {
+ memmove(p12_I + p12_Slen, p12_P, p12_Plen);
+ }
+
+ /*
+ * 5. Set c = ceil(n/u).
+ */
+ unsigned p12_c = (p12_n + p12_u - 1) / p12_u;
+
+ /* allocate c hash-output-size bufs */
+ unsigned char *p12_A = (unsigned char *)coder.malloc(p12_c * p12_u);
+
+ /* one reusable hash object */
+ DigestCtx ourDigest;
+ DigestCtx *hashHand = &ourDigest;
+ memset(hashHand, 0, sizeof(hashHand));
+
+ /* reused inside the loop */
+ unsigned char *p12_B = (unsigned char *)coder.malloc(p12_v + 1);
+ BIGNUM *Ij = BN_new();
+ BIGNUM *Bpl1 = BN_new();
+
+ /*
+ * 6. For i=1, 2, ..., p12_c, do the following:
+ */
+ for(unsigned p12_i=0; p12_i<p12_c; p12_i++) {
+ unsigned char *p12_AsubI = p12_A + (p12_i * p12_u);
+
+ /*
+ * a) Set A[i] = H**r(D||I). (i.e. the rth hash of D||I,
+ * H(H(H(...H(D||I))))
+ */
+ irtn = DigestCtxInit(hashHand, hashAlg);
+ if(!irtn) {
+ ourRtn = CSSMERR_CSP_INTERNAL_ERROR;
+ break;
+ }
+ DigestCtxUpdate(hashHand, p12_D, p12_v);
+ DigestCtxUpdate(hashHand, p12_I, p12_Slen + p12_Plen);
+ DigestCtxFinal(hashHand, p12_AsubI);
+
+ for(unsigned iter=1; iter<p12_r; iter++) {
+ irtn = DigestCtxInit(hashHand, hashAlg);
+ if(!irtn) {
+ ourRtn = CSSMERR_CSP_INTERNAL_ERROR;
+ break;
+ }
+ DigestCtxUpdate(hashHand, p12_AsubI, p12_u);
+ DigestCtxFinal(hashHand, p12_AsubI);
+ }
+
+ /*
+ * b) Concatenate copies of A[i] to create a string B of
+ * length v bits (the final copy of A[i]i may be truncated
+ * to create B).
+ */
+ p12StrCat(p12_AsubI, p12_u, coder, p12_v, p12_B);
+
+ /*
+ * c) Treating I as a concatenation I[0], I[1], ...,
+ * I[k-1] of v-bit blocks, where k = ceil(s/v) + ceil(p/v),
+ * modify I by setting I[j]=(I[j]+B+1) mod (2 ** v)
+ * for each j.
+ *
+ * Copied from PKCS12_key_gen_uni() from openssl...
+ */
+ /* Work out B + 1 first then can use B as tmp space */
+ BN_bin2bn (p12_B, p12_v, Bpl1);
+ BN_add_word (Bpl1, 1);
+ unsigned Ilen = p12_Slen + p12_Plen;
+
+ for (unsigned j = 0; j < Ilen; j+=p12_v) {
+ BN_bin2bn (p12_I + j, p12_v, Ij);
+ BN_add (Ij, Ij, Bpl1);
+ BN_bn2bin (Ij, p12_B);
+ unsigned Ijlen = BN_num_bytes (Ij);
+ /* If more than 2^(v*8) - 1 cut off MSB */
+ if (Ijlen > p12_v) {
+ BN_bn2bin (Ij, p12_B);
+ memcpy (p12_I + j, p12_B + 1, p12_v);
+ /* If less than v bytes pad with zeroes */
+ } else if (Ijlen < p12_v) {
+ memset(p12_I + j, 0, p12_v - Ijlen);
+ BN_bn2bin(Ij, p12_I + j + p12_v - Ijlen);
+ } else BN_bn2bin (Ij, p12_I + j);
+ }
+ }
+
+ if(ourRtn == CSSM_OK) {
+ /*
+ * 7. Concatenate A[1], A[2], ..., A[c] together to form a
+ * pseudo-random bit string, A.
+ *
+ * 8. Use the first n bits of A as the output of this entire
+ * process.
+ */
+ memmove(outbuf, p12_A, outbufLen);
+ }
+
+ /* clear all these strings */
+ if(p12_D) {
+ memset(p12_D, 0, p12_v);
+ }
+ if(p12_S) {
+ memset(p12_S, 0, p12_Slen);
+ }
+ if(p12_P) {
+ memset(p12_P, 0, p12_Plen);
+ }
+ if(p12_I) {
+ memset(p12_I, 0, p12_Slen + p12_Plen);
+ }
+ if(p12_A) {
+ memset(p12_A, 0, p12_c * p12_u);
+ }
+ if(p12_B) {
+ memset(p12_B, 0, p12_v);
+ }
+ if(hashHand) {
+ DigestCtxFree(hashHand);
+ }
+ BN_free(Bpl1);
+ BN_free(Ij);
+ return ourRtn;
+}
+
+/*
+ * Public P12 derive key function, called out from
+ * AppleCSPSession::DeriveKey()
+ *
+ * On input:
+ * ---------
+ * Context parameters:
+ * Salt
+ * Iteration Count
+ * CSSM_CRYPTO_DATA.Param - Unicode passphrase, double-NULL terminated
+ * Algorithm - CSSM_ALGID_PKCS12_PBE_{ENCR,MAC}
+ * Passed explicitly from DeriveKey():
+ * CSSM_DATA Param - IN/OUT - optional IV - caller mallocs space to
+ * tell us to generate an IV. The param itself is not
+ * optional; the presence or absence of allocated data in it
+ * is our IV indicator (present/absent as well as size)
+ * KeyData - mallocd by caller, we fill in keyData->Length bytes
+ */
+void DeriveKey_PKCS12 (
+ const Context &context,
+ AppleCSPSession &session,
+ const CssmData &Param, // other's public key
+ CSSM_DATA *keyData) // mallocd by caller
+ // we fill in keyData->Length bytes
+{
+ SecNssCoder tmpCoder;
+
+ /*
+ * According to the spec, both passphrase and salt are optional.
+ * Get them from context if they're present. In practical terms
+ * the user really should supply a passphrase either in the
+ * seed attribute (as a Unicode passphrase) or as the BaseKey
+ * as a CSSM_ALGID_SECURE_PASSPHRASE key).
+ */
+ CSSM_DATA pwd = {0, NULL};
+ CSSM_DATA appPwd = {0, NULL};
+ CssmCryptoData *cryptData =
+ context.get<CssmCryptoData>(CSSM_ATTRIBUTE_SEED);
+ if((cryptData != NULL) && (cryptData->Param.Length != 0)) {
+ appPwd = cryptData->Param;
+ }
+ else {
+ /* Get pwd from base key */
+ CssmKey *passKey = context.get<CssmKey>(CSSM_ATTRIBUTE_KEY);
+ if (passKey != NULL) {
+ AppleCSPContext::symmetricKeyBits(context, session,
+ CSSM_ALGID_SECURE_PASSPHRASE, CSSM_KEYUSE_DERIVE,
+ appPwd.Data, appPwd.Length);
+ }
+ }
+ if(appPwd.Data) {
+ /*
+ * The incoming passphrase is a UTF8 encoded enternal representation
+ * of a CFString. Convert to CFString and obtain the unicode characters
+ * from the string.
+ */
+ CFDataRef cfData = CFDataCreate(NULL, appPwd.Data, appPwd.Length);
+ CFStringRef cfStr = CFStringCreateFromExternalRepresentation(NULL,
+ cfData, kCFStringEncodingUTF8);
+ if (cfData)
+ CFRelease(cfData);
+ if(cfStr == NULL) {
+ CssmError::throwMe(CSSMERR_CSP_INVALID_ATTR_SEED);
+ }
+
+ /* convert unicode to chars with an extra double-NULL */
+ unsigned len = CFStringGetLength(cfStr);
+ tmpCoder.allocItem(pwd, sizeof(UniChar) * (len + 1));
+ unsigned char *cp = pwd.Data;
+ UniChar uc = 0;
+ for(unsigned dex=0; dex<len; dex++) {
+ uc = CFStringGetCharacterAtIndex(cfStr, dex);
+ *cp++ = uc >> 8;
+ *cp++ = uc & 0xff;
+ }
+ /* CFString tends to include a NULL at the end; add it if it's not there */
+ if(uc == 0) {
+ if(pwd.Length < 2) {
+ CssmError::throwMe(CSSMERR_CSP_INVALID_ATTR_SEED);
+ }
+ pwd.Length -= 2;
+ }
+ else {
+ *cp++ = 0;
+ *cp++ = 0;
+ }
+ if (cfStr)
+ CFRelease(cfStr);
+ }
+
+ /* salt from context */
+ uint32 saltLen = 0;
+ uint8 *salt = NULL;
+ CssmData *csalt = context.get<CssmData>(CSSM_ATTRIBUTE_SALT);
+ if(csalt) {
+ salt = csalt->Data;
+ saltLen = csalt->Length;
+ }
+
+ /*
+ * Iteration count, from context, required.
+ * The spec's ASN1 definition says this is optional with a default
+ * of one but that's a BER encode/decode issue. Here we require
+ * a nonzero value.
+ */
+ uint32 iterCount = context.getInt(CSSM_ATTRIBUTE_ITERATION_COUNT,
+ CSSMERR_CSP_MISSING_ATTR_ITERATION_COUNT);
+ if(iterCount == 0) {
+ CssmError::throwMe(CSSMERR_CSP_INVALID_ATTR_ITERATION_COUNT);
+ }
+
+ /*
+ * Algorithm determines which of {PBE_ID_Key,PBE_ID_MAC} we now
+ * generate. We'll also do an optional PBE_ID_IV later.
+ */
+ P12_PBE_ID pbeId = PBE_ID_Key;
+ switch(context.algorithm()) {
+ case CSSM_ALGID_PKCS12_PBE_ENCR:
+ pbeId = PBE_ID_Key;
+ break;
+ case CSSM_ALGID_PKCS12_PBE_MAC:
+ pbeId = PBE_ID_MAC;
+ break;
+ default:
+ /* really should not be here */
+ assert(0);
+ CssmError::throwMe(CSSMERR_CSP_INTERNAL_ERROR);
+ }
+
+ /* Go */
+ CSSM_RETURN crtn = p12PbeGen(pwd,
+ salt, saltLen,
+ iterCount,
+ pbeId,
+ CSSM_ALGID_SHA1, // all we support for now
+ tmpCoder,
+ keyData->Data,
+ keyData->Length);
+ if(crtn) {
+ CssmError::throwMe(crtn);
+ }
+
+ /*
+ * Optional IV - makes no sense if we just did PBE_ID_MAC, but why
+ * bother restricting?
+ */
+ if(Param.Data) {
+ crtn = p12PbeGen(pwd,
+ salt, saltLen,
+ iterCount,
+ PBE_ID_IV,
+ CSSM_ALGID_SHA1, // all we support for now
+ tmpCoder,
+ Param.Data,
+ Param.Length);
+ if(crtn) {
+ CssmError::throwMe(crtn);
+ }
+ }
+}
+
projects / apple / security.git / blobdiff