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refactor decrypt content with PKCS12 and fix for AES-256 + HMAC SHA25… #2868

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Merged
toddouska merged 1 commit into from
Mar 25, 2020
Merged

refactor decrypt content with PKCS12 and fix for AES-256 + HMAC SHA25… #2868

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260 changes: 68 additions & 192 deletions wolfcrypt/src/asn.c
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Original file line number Diff line number Diff line change
Expand Up @@ -3756,11 +3756,18 @@ int TraditionalEnc(byte* key, word32 keySz, byte* out, word32* outSz,
#endif /* HAVE_PKCS8 */

#if defined(HAVE_PKCS8) || defined(HAVE_PKCS12)

/* Remove Encrypted PKCS8 header, move beginning of traditional to beginning
of input */
int ToTraditionalEnc(byte* input, word32 sz,const char* password,
int passwordSz, word32* algId)
/* decrypt PKCS
*
* NOTE: input buffer is overwritten with decrypted data!
*
* input[in/out] data to decrypt and results are written to
* sz size of input buffer
* password password if used. Can be NULL for no password
* passwordSz size of password buffer
*
* returns the total size of decrypted content on success.
*/
int DecryptContent(byte* input, word32 sz, const char* password, int passwordSz)
{
word32 inOutIdx = 0, seqEnd, oid, shaOid = 0;
int ret = 0, first, second, length = 0, version, saltSz, id;
Expand All @@ -3772,89 +3779,85 @@ int ToTraditionalEnc(byte* input, word32 sz,const char* password,
byte salt[MAX_SALT_SIZE];
byte cbcIv[MAX_IV_SIZE];
#endif
byte tag;

if (passwordSz < 0) {
WOLFSSL_MSG("Bad password size");
return BAD_FUNC_ARG;
}

if (GetSequence(input, &inOutIdx, &length, sz) < 0) {
ERROR_OUT(ASN_PARSE_E, exit_tte);
}

if (GetAlgoId(input, &inOutIdx, &oid, oidIgnoreType, sz) < 0) {
ERROR_OUT(ASN_PARSE_E, exit_tte);
ERROR_OUT(ASN_PARSE_E, exit_dc);
}

first = input[inOutIdx - 2]; /* PKCS version always 2nd to last byte */
second = input[inOutIdx - 1]; /* version.algo, algo id last byte */

if (CheckAlgo(first, second, &id, &version, NULL) < 0) {
ERROR_OUT(ASN_INPUT_E, exit_tte); /* Algo ID error */
ERROR_OUT(ASN_INPUT_E, exit_dc); /* Algo ID error */
}

if (version == PKCS5v2) {
if (GetSequence(input, &inOutIdx, &length, sz) < 0) {
ERROR_OUT(ASN_PARSE_E, exit_tte);
ERROR_OUT(ASN_PARSE_E, exit_dc);
}

if (GetAlgoId(input, &inOutIdx, &oid, oidKdfType, sz) < 0) {
ERROR_OUT(ASN_PARSE_E, exit_tte);
ERROR_OUT(ASN_PARSE_E, exit_dc);
}

if (oid != PBKDF2_OID) {
ERROR_OUT(ASN_PARSE_E, exit_tte);
ERROR_OUT(ASN_PARSE_E, exit_dc);
}
}

if (GetSequence(input, &inOutIdx, &length, sz) <= 0) {
ERROR_OUT(ASN_PARSE_E, exit_tte);
ERROR_OUT(ASN_PARSE_E, exit_dc);
}
/* Find the end of this SEQUENCE so we can check for the OPTIONAL and
* DEFAULT items. */
seqEnd = inOutIdx + length;

ret = GetOctetString(input, &inOutIdx, &saltSz, sz);
if (ret < 0)
goto exit_tte;
goto exit_dc;

if (saltSz > MAX_SALT_SIZE) {
ERROR_OUT(ASN_PARSE_E, exit_tte);
ERROR_OUT(ASN_PARSE_E, exit_dc);
}

#ifdef WOLFSSL_SMALL_STACK
salt = (byte*)XMALLOC(MAX_SALT_SIZE, NULL, DYNAMIC_TYPE_TMP_BUFFER);
if (salt == NULL) {
ERROR_OUT(MEMORY_E, exit_tte);
ERROR_OUT(MEMORY_E, exit_dc);
}
#endif

XMEMCPY(salt, &input[inOutIdx], saltSz);
inOutIdx += saltSz;

if (GetShortInt(input, &inOutIdx, &iterations, sz) < 0) {
ERROR_OUT(ASN_PARSE_E, exit_tte);
ERROR_OUT(ASN_PARSE_E, exit_dc);
}

/* OPTIONAL key length */
if (seqEnd > inOutIdx) {
word32 localIdx = inOutIdx;
byte tag;

if (GetASNTag(input, &localIdx, &tag, sz) < 0) {
ERROR_OUT(ASN_PARSE_E, exit_tte);
ERROR_OUT(ASN_PARSE_E, exit_dc);
}

if (tag == ASN_INTEGER &&
GetShortInt(input, &inOutIdx, &keySz, sz) < 0) {
ERROR_OUT(ASN_PARSE_E, exit_tte);
ERROR_OUT(ASN_PARSE_E, exit_dc);
}
}

/* DEFAULT HMAC is SHA-1 */
if (seqEnd > inOutIdx) {
if (GetAlgoId(input, &inOutIdx, &oid, oidHmacType, sz) < 0) {
ERROR_OUT(ASN_PARSE_E, exit_tte);
ERROR_OUT(ASN_PARSE_E, exit_dc);
}

shaOid = oid;
Expand All @@ -3863,51 +3866,83 @@ int ToTraditionalEnc(byte* input, word32 sz,const char* password,
#ifdef WOLFSSL_SMALL_STACK
cbcIv = (byte*)XMALLOC(MAX_IV_SIZE, NULL, DYNAMIC_TYPE_TMP_BUFFER);
if (cbcIv == NULL) {
ERROR_OUT(MEMORY_E, exit_tte);
ERROR_OUT(MEMORY_E, exit_dc);
}
#endif

if (version == PKCS5v2) {
/* get encryption algo */
if (GetAlgoId(input, &inOutIdx, &oid, oidBlkType, sz) < 0) {
ERROR_OUT(ASN_PARSE_E, exit_tte);
ERROR_OUT(ASN_PARSE_E, exit_dc);
}

if (CheckAlgoV2(oid, &id, NULL) < 0) {
ERROR_OUT(ASN_PARSE_E, exit_tte); /* PKCS v2 algo id error */
ERROR_OUT(ASN_PARSE_E, exit_dc); /* PKCS v2 algo id error */
}

if (shaOid == 0)
shaOid = oid;

ret = GetOctetString(input, &inOutIdx, &length, sz);
if (ret < 0)
goto exit_tte;
goto exit_dc;

if (length > MAX_IV_SIZE) {
ERROR_OUT(ASN_PARSE_E, exit_tte);
ERROR_OUT(ASN_PARSE_E, exit_dc);
}

XMEMCPY(cbcIv, &input[inOutIdx], length);
inOutIdx += length;
}

ret = GetOctetString(input, &inOutIdx, &length, sz);
if (ret < 0)
goto exit_tte;
if (GetASNTag(input, &inOutIdx, &tag, sz) < 0) {
ERROR_OUT(ASN_PARSE_E, exit_dc);
}

if (tag != (ASN_CONTEXT_SPECIFIC | 0) && tag != ASN_OCTET_STRING) {
ERROR_OUT(ASN_PARSE_E, exit_dc);
}

if (GetLength(input, &inOutIdx, &length, sz) < 0) {
ERROR_OUT(ASN_PARSE_E, exit_dc);
}

ret = wc_CryptKey(password, passwordSz, salt, saltSz, iterations, id,
input + inOutIdx, length, version, cbcIv, 0, shaOid);

exit_tte:
exit_dc:
#ifdef WOLFSSL_SMALL_STACK
XFREE(salt, NULL, DYNAMIC_TYPE_TMP_BUFFER);
XFREE(cbcIv, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif

if (ret == 0) {
XMEMMOVE(input, input + inOutIdx, length);
ret = ToTraditional_ex(input, length, algId);
ret = length;
}

return ret;
}


/* Remove Encrypted PKCS8 header, move beginning of traditional to beginning
of input */
int ToTraditionalEnc(byte* input, word32 sz,const char* password,
int passwordSz, word32* algId)
{
int ret, length;
word32 inOutIdx = 0;

if (GetSequence(input, &inOutIdx, &length, sz) < 0) {
ret = ASN_PARSE_E;
}
else {
ret = DecryptContent(input + inOutIdx, sz - inOutIdx, password,
passwordSz);
if (ret > 0) {
XMEMMOVE(input, input + inOutIdx, ret);
ret = ToTraditional_ex(input, ret, algId);
}
}

return ret;
Expand Down Expand Up @@ -4124,165 +4159,6 @@ int EncryptContent(byte* input, word32 inputSz, byte* out, word32* outSz,
}


/* decrypt PKCS
*
* NOTE: input buffer is overwritten with decrypted data!
*
* input[in/out] data to decrypt and results are written to
* sz size of input buffer
* password password if used. Can be NULL for no password
* passwordSz size of password buffer
*
* returns the total size of decrypted content on success.
*/
int DecryptContent(byte* input, word32 sz,const char* password, int passwordSz)
{
word32 inOutIdx = 0, seqEnd, oid;
int ret = 0;
int first, second, length = 0, version, saltSz, id;
int iterations = 0, keySz = 0;
#ifdef WOLFSSL_SMALL_STACK
byte* salt = NULL;
byte* cbcIv = NULL;
#else
byte salt[MAX_SALT_SIZE];
byte cbcIv[MAX_IV_SIZE];
#endif
byte tag;

if (GetAlgoId(input, &inOutIdx, &oid, oidIgnoreType, sz) < 0) {
ERROR_OUT(ASN_PARSE_E, exit_dc);
}

first = input[inOutIdx - 2]; /* PKCS version always 2nd to last byte */
second = input[inOutIdx - 1]; /* version.algo, algo id last byte */

if (CheckAlgo(first, second, &id, &version, NULL) < 0) {
ERROR_OUT(ASN_INPUT_E, exit_dc); /* Algo ID error */
}

if (version == PKCS5v2) {
if (GetSequence(input, &inOutIdx, &length, sz) < 0) {
ERROR_OUT(ASN_PARSE_E, exit_dc);
}

if (GetAlgoId(input, &inOutIdx, &oid, oidKdfType, sz) < 0) {
ERROR_OUT(ASN_PARSE_E, exit_dc);
}

if (oid != PBKDF2_OID) {
ERROR_OUT(ASN_PARSE_E, exit_dc);
}
}

if (GetSequence(input, &inOutIdx, &length, sz) <= 0) {
ERROR_OUT(ASN_PARSE_E, exit_dc);
}
/* Find the end of this SEQUENCE so we can check for the OPTIONAL and
* DEFAULT items. */
seqEnd = inOutIdx + length;

ret = GetOctetString(input, &inOutIdx, &saltSz, sz);
if (ret < 0)
goto exit_dc;

if (saltSz > MAX_SALT_SIZE) {
ERROR_OUT(ASN_PARSE_E, exit_dc);
}

#ifdef WOLFSSL_SMALL_STACK
salt = (byte*)XMALLOC(MAX_SALT_SIZE, NULL, DYNAMIC_TYPE_TMP_BUFFER);
if (salt == NULL) {
ERROR_OUT(MEMORY_E, exit_dc);
}
#endif

XMEMCPY(salt, &input[inOutIdx], saltSz);
inOutIdx += saltSz;

if (GetShortInt(input, &inOutIdx, &iterations, sz) < 0) {
ERROR_OUT(ASN_PARSE_E, exit_dc);
}

/* OPTIONAL key length */
if (seqEnd > inOutIdx) {
word32 localIdx = inOutIdx;

if (GetASNTag(input, &localIdx, &tag, sz) < 0) {
ERROR_OUT(ASN_PARSE_E, exit_dc);
}

if (tag == ASN_INTEGER &&
GetShortInt(input, &inOutIdx, &keySz, sz) < 0) {
ERROR_OUT(ASN_PARSE_E, exit_dc);
}
}

/* DEFAULT HMAC is SHA-1 */
if (seqEnd > inOutIdx) {
if (GetAlgoId(input, &inOutIdx, &oid, oidHmacType, sz) < 0) {
ERROR_OUT(ASN_PARSE_E, exit_dc);
}
}

#ifdef WOLFSSL_SMALL_STACK
cbcIv = (byte*)XMALLOC(MAX_IV_SIZE, NULL, DYNAMIC_TYPE_TMP_BUFFER);
if (cbcIv == NULL) {
ERROR_OUT(MEMORY_E, exit_dc);
}
#endif

if (version == PKCS5v2) {
/* get encryption algo */
if (GetAlgoId(input, &inOutIdx, &oid, oidBlkType, sz) < 0) {
ERROR_OUT(ASN_PARSE_E, exit_dc);
}

if (CheckAlgoV2(oid, &id, NULL) < 0) {
ERROR_OUT(ASN_PARSE_E, exit_dc); /* PKCS v2 algo id error */
}

ret = GetOctetString(input, &inOutIdx, &length, sz);
if (ret < 0)
goto exit_dc;

if (length > MAX_IV_SIZE) {
ERROR_OUT(ASN_PARSE_E, exit_dc);
}

XMEMCPY(cbcIv, &input[inOutIdx], length);
inOutIdx += length;
}

if (GetASNTag(input, &inOutIdx, &tag, sz) < 0) {
ERROR_OUT(ASN_PARSE_E, exit_dc);
}

if (tag != (ASN_CONTEXT_SPECIFIC | 0)) {
ERROR_OUT(ASN_PARSE_E, exit_dc);
}

if (GetLength(input, &inOutIdx, &length, sz) < 0) {
ERROR_OUT(ASN_PARSE_E, exit_dc);
}

ret = wc_CryptKey(password, passwordSz, salt, saltSz, iterations, id,
input + inOutIdx, length, version, cbcIv, 0, 0);
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@dgarske dgarske Mar 25, 2020

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For reference the bug was here on the last arg of wc_CryptKey call, which was not providing shaOid on the last arg.


exit_dc:

#ifdef WOLFSSL_SMALL_STACK
XFREE(salt, NULL, DYNAMIC_TYPE_TMP_BUFFER);
XFREE(cbcIv, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif

if (ret == 0) {
XMEMMOVE(input, input + inOutIdx, length);
ret = length;
}

return ret;
}
#endif /* HAVE_PKCS12 */
#endif /* NO_PWDBASED */

Expand Down