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pkcs7: refactoring PKCS7_DecodeEnvelopedData to reduce stack usage: ~ 9 * sizeof(mp_int) bytes + 512 bytes moved to the heap.

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--- variable privKey moved to the heap (more than 8 * sizeof(mp_int) bytes saved)
--- variable encryptedKey moved to the heap (512 bytes saved)
--- variable serialNum moved to the heap (sizeof(mp_int) bytes saved)
This commit is contained in:
Moisés Guimarães
2014-06-19 12:51:59 -03:00
parent 21982b50db
commit 46d0f68097
1 changed files with 194 additions and 52 deletions
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216
ctaocrypt/src/pkcs7.c
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@@ -1410,14 +1410,23 @@ CYASSL_API int PKCS7_DecodeEnvelopedData(PKCS7* pkcs7, byte* pkiMsg,
word32 savedIdx = 0, idx = 0; word32 savedIdx = 0, idx = 0;
word32 contentType, encOID; word32 contentType, encOID;
byte issuerHash[SHA_DIGEST_SIZE]; byte issuerHash[SHA_DIGEST_SIZE];
mp_int serialNum;
int encryptedKeySz, keySz; int encryptedKeySz, keySz;
byte tmpIv[DES_BLOCK_SIZE]; byte tmpIv[DES_BLOCK_SIZE];
byte encryptedKey[MAX_ENCRYPTED_KEY_SZ];
byte* decryptedKey = NULL; byte* decryptedKey = NULL;
RsaKey privKey; #ifdef CYASSL_SMALL_STACK
mp_int* serialNum;
byte* encryptedKey;
RsaKey* privKey;
#else
mp_int stack_serialNum;
mp_int* serialNum = &stack_serialNum;
byte encryptedKey[MAX_ENCRYPTED_KEY_SZ];
RsaKey stack_privKey;
RsaKey* privKey = &stack_privKey;
#endif
int encryptedContentSz; int encryptedContentSz;
byte padLen; byte padLen;
byte* encryptedContent = NULL; byte* encryptedContent = NULL;
@@ -1431,18 +1440,6 @@ CYASSL_API int PKCS7_DecodeEnvelopedData(PKCS7* pkcs7, byte* pkiMsg,
output == NULL || outputSz == 0) output == NULL || outputSz == 0)
return BAD_FUNC_ARG; return BAD_FUNC_ARG;
/* load private key */
ret = InitRsaKey(&privKey, 0);
if (ret != 0) return ret;
ret = RsaPrivateKeyDecode(pkcs7->privateKey, &idx, &privKey,
pkcs7->privateKeySz);
if (ret != 0) {
CYASSL_MSG("Failed to decode RSA private key");
return ret;
}
idx = 0;
/* read past ContentInfo, verify type is envelopedData */ /* read past ContentInfo, verify type is envelopedData */
if (GetSequence(pkiMsg, &idx, &length, pkiMsgSz) < 0) if (GetSequence(pkiMsg, &idx, &length, pkiMsgSz) < 0)
return ASN_PARSE_E; return ASN_PARSE_E;
@@ -1477,6 +1474,13 @@ CYASSL_API int PKCS7_DecodeEnvelopedData(PKCS7* pkcs7, byte* pkiMsg,
if (GetSet(pkiMsg, &idx, &length, pkiMsgSz) < 0) if (GetSet(pkiMsg, &idx, &length, pkiMsgSz) < 0)
return ASN_PARSE_E; return ASN_PARSE_E;
#ifdef CYASSL_SMALL_STACK
encryptedKey = (byte*) XMALLOC(MAX_ENCRYPTED_KEY_SZ, NULL,
DYNAMIC_TYPE_TMP_BUFFER);
if (encryptedKey == NULL)
return MEMORY_E;
#endif
savedIdx = idx; savedIdx = idx;
recipFound = 0; recipFound = 0;
@@ -1496,38 +1500,85 @@ CYASSL_API int PKCS7_DecodeEnvelopedData(PKCS7* pkcs7, byte* pkiMsg,
break; break;
} }
if (version != 0) if (version != 0) {
#ifdef CYASSL_SMALL_STACK
XFREE(encryptedKey, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif
return ASN_VERSION_E; return ASN_VERSION_E;
}
/* remove IssuerAndSerialNumber */ /* remove IssuerAndSerialNumber */
if (GetSequence(pkiMsg, &idx, &length, pkiMsgSz) < 0) if (GetSequence(pkiMsg, &idx, &length, pkiMsgSz) < 0) {
#ifdef CYASSL_SMALL_STACK
XFREE(encryptedKey, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif
return ASN_PARSE_E; return ASN_PARSE_E;
}
if (GetNameHash(pkiMsg, &idx, issuerHash, pkiMsgSz) < 0) if (GetNameHash(pkiMsg, &idx, issuerHash, pkiMsgSz) < 0) {
#ifdef CYASSL_SMALL_STACK
XFREE(encryptedKey, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif
return ASN_PARSE_E; return ASN_PARSE_E;
}
/* if we found correct recipient, issuer hashes will match */ /* if we found correct recipient, issuer hashes will match */
if (XMEMCMP(issuerHash, pkcs7->issuerHash, SHA_DIGEST_SIZE) == 0) { if (XMEMCMP(issuerHash, pkcs7->issuerHash, SHA_DIGEST_SIZE) == 0) {
recipFound = 1; recipFound = 1;
} }
if (GetInt(&serialNum, pkiMsg, &idx, pkiMsgSz) < 0) #ifdef CYASSL_SMALL_STACK
return ASN_PARSE_E; serialNum = (mp_int*)XMALLOC(sizeof(mp_int), NULL,
mp_clear(&serialNum); DYNAMIC_TYPE_TMP_BUFFER);
if (serialNum == NULL) {
XFREE(encryptedKey, NULL, DYNAMIC_TYPE_TMP_BUFFER);
return MEMORY_E;
}
#endif
if (GetAlgoId(pkiMsg, &idx, &encOID, pkiMsgSz) < 0) if (GetInt(serialNum, pkiMsg, &idx, pkiMsgSz) < 0) {
#ifdef CYASSL_SMALL_STACK
XFREE(encryptedKey, NULL, DYNAMIC_TYPE_TMP_BUFFER);
XFREE(serialNum, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif
return ASN_PARSE_E; return ASN_PARSE_E;
}
mp_clear(serialNum);
#ifdef CYASSL_SMALL_STACK
XFREE(serialNum, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif
if (GetAlgoId(pkiMsg, &idx, &encOID, pkiMsgSz) < 0) {
#ifdef CYASSL_SMALL_STACK
XFREE(encryptedKey, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif
return ASN_PARSE_E;
}
/* key encryption algorithm must be RSA for now */ /* key encryption algorithm must be RSA for now */
if (encOID != RSAk) if (encOID != RSAk) {
#ifdef CYASSL_SMALL_STACK
XFREE(encryptedKey, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif
return ALGO_ID_E; return ALGO_ID_E;
}
/* read encryptedKey */ /* read encryptedKey */
if (pkiMsg[idx++] != ASN_OCTET_STRING) if (pkiMsg[idx++] != ASN_OCTET_STRING) {
#ifdef CYASSL_SMALL_STACK
XFREE(encryptedKey, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif
return ASN_PARSE_E; return ASN_PARSE_E;
}
if (GetLength(pkiMsg, &idx, &encryptedKeySz, pkiMsgSz) < 0) if (GetLength(pkiMsg, &idx, &encryptedKeySz, pkiMsgSz) < 0) {
#ifdef CYASSL_SMALL_STACK
XFREE(encryptedKey, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif
return ASN_PARSE_E; return ASN_PARSE_E;
}
if (recipFound == 1) if (recipFound == 1)
XMEMCPY(encryptedKey, &pkiMsg[idx], encryptedKeySz); XMEMCPY(encryptedKey, &pkiMsg[idx], encryptedKeySz);
@@ -1539,28 +1590,54 @@ CYASSL_API int PKCS7_DecodeEnvelopedData(PKCS7* pkcs7, byte* pkiMsg,
if (recipFound == 0) { if (recipFound == 0) {
CYASSL_MSG("No recipient found in envelopedData that matches input"); CYASSL_MSG("No recipient found in envelopedData that matches input");
#ifdef CYASSL_SMALL_STACK
XFREE(encryptedKey, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif
return PKCS7_RECIP_E; return PKCS7_RECIP_E;
} }
/* remove EncryptedContentInfo */ /* remove EncryptedContentInfo */
if (GetSequence(pkiMsg, &idx, &length, pkiMsgSz) < 0) if (GetSequence(pkiMsg, &idx, &length, pkiMsgSz) < 0) {
#ifdef CYASSL_SMALL_STACK
XFREE(encryptedKey, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif
return ASN_PARSE_E; return ASN_PARSE_E;
}
if (GetContentType(pkiMsg, &idx, &contentType, pkiMsgSz) < 0) if (GetContentType(pkiMsg, &idx, &contentType, pkiMsgSz) < 0) {
#ifdef CYASSL_SMALL_STACK
XFREE(encryptedKey, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif
return ASN_PARSE_E; return ASN_PARSE_E;
}
if (GetAlgoId(pkiMsg, &idx, &encOID, pkiMsgSz) < 0) if (GetAlgoId(pkiMsg, &idx, &encOID, pkiMsgSz) < 0) {
#ifdef CYASSL_SMALL_STACK
XFREE(encryptedKey, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif
return ASN_PARSE_E; return ASN_PARSE_E;
}
/* get block cipher IV, stored in OPTIONAL parameter of AlgoID */ /* get block cipher IV, stored in OPTIONAL parameter of AlgoID */
if (pkiMsg[idx++] != ASN_OCTET_STRING) if (pkiMsg[idx++] != ASN_OCTET_STRING) {
#ifdef CYASSL_SMALL_STACK
XFREE(encryptedKey, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif
return ASN_PARSE_E; return ASN_PARSE_E;
}
if (GetLength(pkiMsg, &idx, &length, pkiMsgSz) < 0) if (GetLength(pkiMsg, &idx, &length, pkiMsgSz) < 0) {
#ifdef CYASSL_SMALL_STACK
XFREE(encryptedKey, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif
return ASN_PARSE_E; return ASN_PARSE_E;
}
if (length != DES_BLOCK_SIZE) { if (length != DES_BLOCK_SIZE) {
CYASSL_MSG("Incorrect IV length, must be of DES_BLOCK_SIZE"); CYASSL_MSG("Incorrect IV length, must be of DES_BLOCK_SIZE");
#ifdef CYASSL_SMALL_STACK
XFREE(encryptedKey, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif
return ASN_PARSE_E; return ASN_PARSE_E;
} }
@@ -1568,25 +1645,78 @@ CYASSL_API int PKCS7_DecodeEnvelopedData(PKCS7* pkcs7, byte* pkiMsg,
idx += length; idx += length;
/* read encryptedContent, cont[0] */ /* read encryptedContent, cont[0] */
if (pkiMsg[idx++] != (ASN_CONTEXT_SPECIFIC | 0)) if (pkiMsg[idx++] != (ASN_CONTEXT_SPECIFIC | 0)) {
#ifdef CYASSL_SMALL_STACK
XFREE(encryptedKey, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif
return ASN_PARSE_E; return ASN_PARSE_E;
}
if (GetLength(pkiMsg, &idx, &encryptedContentSz, pkiMsgSz) < 0) if (GetLength(pkiMsg, &idx, &encryptedContentSz, pkiMsgSz) < 0) {
#ifdef CYASSL_SMALL_STACK
XFREE(encryptedKey, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif
return ASN_PARSE_E; return ASN_PARSE_E;
}
encryptedContent = XMALLOC(encryptedContentSz, NULL, encryptedContent = (byte*)XMALLOC(encryptedContentSz, NULL,
DYNAMIC_TYPE_TMP_BUFFER); DYNAMIC_TYPE_TMP_BUFFER);
if (encryptedContent == NULL) if (encryptedContent == NULL) {
#ifdef CYASSL_SMALL_STACK
XFREE(encryptedKey, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif
return MEMORY_E; return MEMORY_E;
}
XMEMCPY(encryptedContent, &pkiMsg[idx], encryptedContentSz); XMEMCPY(encryptedContent, &pkiMsg[idx], encryptedContentSz);
/* load private key */
#ifdef CYASSL_SMALL_STACK
privKey = (RsaKey*)XMALLOC(sizeof(RsaKey), NULL, DYNAMIC_TYPE_TMP_BUFFER);
if (privKey == NULL) {
XFREE(encryptedContent, NULL, DYNAMIC_TYPE_TMP_BUFFER);
XFREE(encryptedKey, NULL, DYNAMIC_TYPE_TMP_BUFFER); return MEMORY_E;
}
#endif
ret = InitRsaKey(privKey, 0);
if (ret != 0) {
XFREE(encryptedContent, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#ifdef CYASSL_SMALL_STACK
XFREE(privKey, NULL, DYNAMIC_TYPE_TMP_BUFFER);
XFREE(encryptedKey, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif
return ret;
}
idx = 0;
ret = RsaPrivateKeyDecode(pkcs7->privateKey, &idx, privKey,
pkcs7->privateKeySz);
if (ret != 0) {
CYASSL_MSG("Failed to decode RSA private key");
XFREE(encryptedContent, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#ifdef CYASSL_SMALL_STACK
XFREE(privKey, NULL, DYNAMIC_TYPE_TMP_BUFFER);
XFREE(encryptedKey, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif
return ret;
}
/* decrypt encryptedKey */ /* decrypt encryptedKey */
keySz = RsaPrivateDecryptInline(encryptedKey, encryptedKeySz, keySz = RsaPrivateDecryptInline(encryptedKey, encryptedKeySz,
&decryptedKey, &privKey); &decryptedKey, privKey);
FreeRsaKey(&privKey); FreeRsaKey(privKey);
#ifdef CYASSL_SMALL_STACK
XFREE(privKey, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif
if (keySz <= 0) { if (keySz <= 0) {
XFREE(encryptedContent, NULL, DYNAMIC_TYPE_TMP_BUFFER); XFREE(encryptedContent, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#ifdef CYASSL_SMALL_STACK
XFREE(encryptedKey, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif
return keySz; return keySz;
} }
@@ -1601,6 +1731,9 @@ CYASSL_API int PKCS7_DecodeEnvelopedData(PKCS7* pkcs7, byte* pkiMsg,
if (ret != 0) { if (ret != 0) {
XFREE(encryptedContent, NULL, DYNAMIC_TYPE_TMP_BUFFER); XFREE(encryptedContent, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#ifdef CYASSL_SMALL_STACK
XFREE(encryptedKey, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif
return ret; return ret;
} }
} }
@@ -1613,11 +1746,17 @@ CYASSL_API int PKCS7_DecodeEnvelopedData(PKCS7* pkcs7, byte* pkiMsg,
if (ret != 0) { if (ret != 0) {
XFREE(encryptedContent, NULL, DYNAMIC_TYPE_TMP_BUFFER); XFREE(encryptedContent, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#ifdef CYASSL_SMALL_STACK
XFREE(encryptedKey, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif
return ret; return ret;
} }
} else { } else {
CYASSL_MSG("Unsupported content encryption OID type"); CYASSL_MSG("Unsupported content encryption OID type");
XFREE(encryptedContent, NULL, DYNAMIC_TYPE_TMP_BUFFER); XFREE(encryptedContent, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#ifdef CYASSL_SMALL_STACK
XFREE(encryptedKey, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif
return ALGO_ID_E; return ALGO_ID_E;
} }
@@ -1630,6 +1769,9 @@ CYASSL_API int PKCS7_DecodeEnvelopedData(PKCS7* pkcs7, byte* pkiMsg,
XMEMSET(encryptedKey, 0, MAX_ENCRYPTED_KEY_SZ); XMEMSET(encryptedKey, 0, MAX_ENCRYPTED_KEY_SZ);
XMEMSET(encryptedContent, 0, encryptedContentSz); XMEMSET(encryptedContent, 0, encryptedContentSz);
XFREE(encryptedContent, NULL, DYNAMIC_TYPE_TMP_BUFFER); XFREE(encryptedContent, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#ifdef CYASSL_SMALL_STACK
XFREE(encryptedKey, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif
return encryptedContentSz - padLen; return encryptedContentSz - padLen;
} }