1 files changed, 147 insertions, 0 deletions
diff --git a/src/tcs/tcsi_random.c b/src/tcs/tcsi_random.c
new file mode 100644
index 0000000..9670df4
--- /dev/null
+++ b/src/tcs/tcsi_random.c
@@ -0,0 +1,147 @@
+
+/*
+ * Licensed Materials - Property of IBM
+ *
+ * trousers - An open source TCG Software Stack
+ *
+ * (C) Copyright International Business Machines Corp. 2004
+ *
+ */
+
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <inttypes.h>
+
+#include "trousers/tss.h"
+#include "trousers_types.h"
+#include "tcs_tsp.h"
+#include "tcsps.h"
+#include "tcs_utils.h"
+#include "tcs_int_literals.h"
+#include "capabilities.h"
+#include "tcslog.h"
+#include "req_mgr.h"
+#include "tcsd_wrap.h"
+#include "tcsd.h"
+
+
+/*
+ * Get a random number generated by the TPM.  Most (all?) TPMs return a maximum number of random
+ * bytes that's less than the max allowed to be returned at the TSP level, which is 4K bytes.
+ * According to the TPM compliance work posted here: http://www.prosec.rub.de/tpmcompliance.html,
+ * some TPMs return as little as 132 bytes per query, which would require about 30 loops to get 4K.
+ * We'll be extremely conservative here and loop 50 times, since it won't affect performance on
+ * TPMs that return more bytes.
+ */
+TSS_RESULT
+TCSP_GetRandom_Internal(TCS_CONTEXT_HANDLE hContext,	/* in */
+			UINT32 * bytesRequested,	/* in, out */
+			BYTE ** randomBytes)	/* out */
+{
+	UINT64 offset;
+	TSS_RESULT result;
+	UINT32 paramSize, totalReturned = 0, bytesReturned, retries = 50;
+	BYTE txBlob[TSS_TPM_TXBLOB_SIZE], *rnd_tmp = NULL, *rnd_tmp2 = NULL;
+
+	LogDebugFn("%u bytes", *bytesRequested);
+
+	if ((result = ctx_verify_context(hContext)))
+		return result;
+
+	do {
+		offset = 0;
+		if ((result = tpm_rqu_build(TPM_ORD_GetRandom, &offset, txBlob,
+					    *bytesRequested - totalReturned, NULL)))
+			break;
+
+		if ((result = req_mgr_submit_req(txBlob)))
+			break;;
+
+		result = UnloadBlob_Header(txBlob, &paramSize);
+		if (!result) {
+#if 0
+			offset = 10;
+			UnloadBlob_UINT32(&offset, &bytesReturned, txBlob);
+
+			LogDebugFn("received %u bytes from the TPM", bytesReturned);
+
+			rnd_tmp = realloc(rnd_tmp, totalReturned + bytesReturned);
+			if (rnd_tmp == NULL) {
+				LogError("malloc of %u bytes failed.", bytesReturned);
+				return TCSERR(TSS_E_OUTOFMEMORY);
+			}
+			UnloadBlob(&offset, bytesReturned, txBlob, &rnd_tmp[totalReturned]);
+#else
+			/* XXX */
+			if ((result = tpm_rsp_parse(TPM_ORD_GetRandom, txBlob, paramSize,
+						    &bytesReturned, &rnd_tmp, NULL, NULL)))
+				break;
+
+			rnd_tmp2 = realloc(*randomBytes, totalReturned + bytesReturned);
+			if (rnd_tmp2 == NULL) {
+				free(rnd_tmp);
+				rnd_tmp = NULL;
+				LogError("malloc of %u bytes failed.", bytesReturned);
+				result = TCSERR(TSS_E_OUTOFMEMORY);
+				break;
+			}
+			*randomBytes = rnd_tmp2;
+			memcpy(*randomBytes + totalReturned, rnd_tmp, bytesReturned);
+			free(rnd_tmp);
+			rnd_tmp = NULL;
+#endif
+			totalReturned += bytesReturned;
+		} else {
+			free(rnd_tmp);
+			return result;
+		}
+	} while (totalReturned < *bytesRequested && retries--);
+
+	if (totalReturned != *bytesRequested) {
+		LogDebugFn("Only %u random bytes recieved from TPM.", totalReturned);
+		free(rnd_tmp);
+		result = TCSERR(TSS_E_FAIL);
+#if 0
+	} else
+		*randomBytes = rnd_tmp;
+#else
+	}
+#endif
+
+	return result;
+}
+
+TSS_RESULT
+TCSP_StirRandom_Internal(TCS_CONTEXT_HANDLE hContext,	/* in */
+			 UINT32 inDataSize,	/* in */
+			 BYTE * inData)	/* in */
+{
+	UINT64 offset = 0;
+	UINT32 paramSize;
+	TSS_RESULT result;
+	BYTE txBlob[TSS_TPM_TXBLOB_SIZE];
+
+	LogDebug("Entering stir random");
+
+	if (inDataSize > 255) {
+		LogDebugFn("inData is too large! (%u bytes)", inDataSize);
+		return TCSERR(TSS_E_BAD_PARAMETER);
+	}
+
+	if ((result = ctx_verify_context(hContext)))
+		return result;
+
+	if ((result = tpm_rqu_build(TPM_ORD_StirRandom, &offset, txBlob, inDataSize, inDataSize,
+				    inData, NULL, NULL)))
+		return result;
+
+	if ((result = req_mgr_submit_req(txBlob)))
+		return result;
+
+	result = UnloadBlob_Header(txBlob, &paramSize);
+	LogResult("Stir random", result);
+	return result;
+}
+