64 decoding sanity checks

This commit is contained in:
toddouska 2012-06-01 14:37:59 -07:00
parent 8a52cd3780
commit 32fc5daf43

View File

@ -54,6 +54,7 @@ int Base64_Decode(const byte* in, word32 inLen, byte* out, word32* outLen)
word32 i = 0;
word32 j = 0;
word32 plainSz = inLen - ((inLen + (PEM_LINE_SZ - 1)) / PEM_LINE_SZ );
const byte maxIdx = (byte)sizeof(base64Decode) + 0x2B - 1;
plainSz = (plainSz * 3 + 3) / 4;
if (plainSz > *outLen) return BAD_FUNC_ARG;
@ -75,6 +76,16 @@ int Base64_Decode(const byte* in, word32 inLen, byte* out, word32* outLen)
if (e4 == PAD)
pad4 = 1;
if (e1 < 0x2B || e2 < 0x2B || e3 < 0x2B || e4 < 0x2B) {
CYASSL_MSG("Bad Base64 Decode data, too small");
return ASN_INPUT_E;
}
if (e1 > maxIdx || e2 > maxIdx || e3 > maxIdx || e4 > maxIdx) {
CYASSL_MSG("Bad Base64 Decode data, too big");
return ASN_INPUT_E;
}
e1 = base64Decode[e1 - 0x2B];
e2 = base64Decode[e2 - 0x2B];
e3 = (e3 == PAD) ? 0 : base64Decode[e3 - 0x2B];