1 // This file was extracted from the TCG Published 2 // Trusted Platform Module Library 3 // Part 4: Supporting Routines 4 // Family "2.0" 5 // Level 00 Revision 01.16 6 // October 30, 2014 7 8 #include "OsslCryptoEngine.h" 9 // 10 // 11 // Functions 12 // 13 // BnTo2B() 14 // 15 // This function is used to convert a BigNum() to a byte array of the specified size. If the number is too large 16 // to fit, then 0 is returned. Otherwise, the number is converted into the low-order bytes of the provided array 17 // and the upper bytes are set to zero. 18 // 19 // Return Value Meaning 20 // 21 // 0 failure (probably fatal) 22 // 1 conversion successful 23 // 24 BOOL 25 BnTo2B( 26 TPM2B *outVal, // OUT: place for the result 27 BIGNUM *inVal, // IN: number to convert 28 UINT16 size // IN: size of the output. 29 ) 30 { 31 BYTE *pb = outVal->buffer; 32 outVal->size = size; 33 size = size - (((UINT16) BN_num_bits(inVal) + 7) / 8); 34 if(size < 0) 35 return FALSE; 36 for(;size > 0; size--) 37 *pb++ = 0; 38 BN_bn2bin(inVal, pb); 39 return TRUE; 40 } 41 // 42 // 43 // Copy2B() 44 // 45 // This function copies a TPM2B structure. The compiler can't generate a copy of a TPM2B generic 46 // structure because the actual size is not known. This function performs the copy on any TPM2B pair. The 47 // size of the destination should have been checked before this call to make sure that it will hold the TPM2B 48 // being copied. 49 // This replicates the functionality in the MemoryLib.c. 50 // 51 void 52 Copy2B( 53 TPM2B *out, // OUT: The TPM2B to receive the copy 54 TPM2B *in // IN: the TPM2B to copy 55 ) 56 { 57 BYTE *pIn = in->buffer; 58 BYTE *pOut = out->buffer; 59 int count; 60 out->size = in->size; 61 for(count = in->size; count > 0; count--) 62 *pOut++ = *pIn++; 63 return; 64 } 65 // 66 // 67 // BnFrom2B() 68 // 69 // This function creates a BIGNUM from a TPM2B and fails if the conversion fails. 70 // 71 BIGNUM * 72 BnFrom2B( 73 BIGNUM *out, // OUT: The BIGNUM 74 const TPM2B *in // IN: the TPM2B to copy 75 ) 76 { 77 if(BN_bin2bn(in->buffer, in->size, out) == NULL) 78 FAIL(FATAL_ERROR_INTERNAL); 79 return out; 80 } 81
