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qaisjp/ssl.c

Last active Dec 7, 2019
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Do not delete - used in Better Informatics, Secure Programming, 2014 May
static OSStatus
SSLVerifySignedServerKeyExchange(SSLContext * ctx,
bool isRsa, SSLBuffer signedParams,
uint8_t * signature, UInt16 signatureLen)
{
OSStatus err;
SSLBuffer hashOut, hashCtx, clientRandom, serverRandom;
uint8_t hashes[SSL_SHA1_DIGEST_LEN + SSL_MD5_DIGEST_LEN];
SSLBuffer signedHashes;
uint8_t * dataToSign;
size_t dataToSignLen;
signedHashes.data = 0;
hashCtx.data = 0;
clientRandom.data = ctx - > clientRandom;
clientRandom.length = SSL_CLIENT_SRVR_RAND_SIZE;
serverRandom.data = ctx - > serverRandom;
serverRandom.length = SSL_CLIENT_SRVR_RAND_SIZE;
if (isRsa) {
/* skip this if signing with DSA */
dataToSign = hashes;
dataToSignLen = SSL_SHA1_DIGEST_LEN + SSL_MD5_DIGEST_LEN;
hashOut.data = hashes;
hashOut.length = SSL_MD5_DIGEST_LEN;
if ((err = ReadyHash( & SSLHashMD5, & hashCtx)) != 0)
goto fail;
if ((err = SSLHashMD5.update( & hashCtx, & clientRandom)) != 0)
goto fail;
if ((err = SSLHashMD5.update( & hashCtx, & serverRandom)) != 0)
goto fail;
if ((err = SSLHashMD5.update( & hashCtx, & signedParams)) != 0)
goto fail;
if ((err = SSLHashMD5.final( & hashCtx, & hashOut)) != 0)
goto fail;
}
else {
/* DSA, ECDSA - just use the SHA1 hash */
dataToSign = & hashes[SSL_MD5_DIGEST_LEN];
dataToSignLen = SSL_SHA1_DIGEST_LEN;
}
hashOut.data = hashes + SSL_MD5_DIGEST_LEN;
hashOut.length = SSL_SHA1_DIGEST_LEN;
if ((err = SSLFreeBuffer( & hashCtx)) != 0)
goto fail;
if ((err = ReadyHash( & SSLHashSHA1, & hashCtx)) != 0)
goto fail;
if ((err = SSLHashSHA1.update( & hashCtx, & clientRandom)) != 0)
goto fail;
if ((err = SSLHashSHA1.update( & hashCtx, & serverRandom)) != 0)
goto fail;
if ((err = SSLHashSHA1.update( & hashCtx, & signedParams)) != 0)
goto fail;
goto fail;
if ((err = SSLHashSHA1.final( & hashCtx, & hashOut)) != 0)
goto fail;
err = sslRawVerify(ctx,
ctx - > peerPubKey,
dataToSign, /* plaintext */
dataToSignLen, /* plaintext length */
signature,
signatureLen);
if (err) {
sslErrorLog("SSLDecodeSignedServerKeyExchange: sslRawVerify "
"returned %d\n", (int) err);
goto fail;
}
fail:
SSLFreeBuffer( & signedHashes);
SSLFreeBuffer( & hashCtx);
return err;
}
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