111 lines
3.0 KiB
C
111 lines
3.0 KiB
C
#include "layer2.h"
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//RIOT core
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void startCDIProtocol()
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{
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//step 1 : Derive Device ID
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uint8_t* UDS_ID = calloc(1,sizeof(uint8_t)*SHA256_DGST_SIZE);
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readUDS(UDS_ID);
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// for(int i = 0; i < SHA256_DGST_SIZE; i++)
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// printf("%x",UDS_ID[i]);
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// printf(" : UDS_ID, main\n");
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//step 2 : Derive Firmware ID
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uint8_t* FW_ID = calloc(1,sizeof(uint8_t)*SHA256_DGST_SIZE);
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readFWID(FW_ID);
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// for(int i = 0; i < SHA256_DGST_SIZE; i++)
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// printf("%x",FW_ID[i]);
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// printf(" : FW_ID, main\n");
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//setp 3 : Derive Composite Device ID
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uint8_t* CD_ID = calloc(1,sizeof(uint8_t)*SHA256_DGST_SIZE);
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calcCDID(UDS_ID,FW_ID,CD_ID);
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free(UDS_ID);
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free(FW_ID);
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// //wrapper funciton to avoid exposing UDS and FW measurements
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// uint8_t* _CD_ID = calloc(1,sizeof(uint8_t)*SHA256_DGST_SIZE);
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// _calcCDID(_CD_ID);
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// printf( "CDID wrap : ");
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// for(int i = 0; i < SHA256_DGST_SIZE; i++)
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// printf("%x",_CD_ID[i]);
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// printf( "\n\n\n");
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uint8_t* KEY_OUT = calloc(1,sizeof(uint8_t)*KDF_KEY_SIZE);
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size_t KEY_LEN = KDF_KEY_SIZE; //need to pass pointer to the out key size, not the value
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if(deriveKDF(KEY_OUT, &KEY_LEN, CD_ID, SHA256_DGST_SIZE, PASSPHRASE, lenofstr(PASSPHRASE)))
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printf("\n\nKDF call success\n");;
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for(int i = 0; i <= KDF_KEY_SIZE; i++)
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printf("%x,",KEY_OUT[i]);
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printf( " : KEY_OUT\n");
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//End block
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free(CD_ID);
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//free(_CD_ID); //for wrapper function
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}
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int deriveKDF(uint8_t * out, size_t * out_len, uint8_t * secret, int secret_len, unsigned char * passphrase, int pass_len)
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{
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//create comtext
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//ctx set params
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//passphrase
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//secret //CDI
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//alg //not taken as input. fixed to sha256
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//salt //meh, hardcode salt too
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//out
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//hkdf derive key
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// for(int i = 0; i < SHA256_DGST_SIZE; i++)
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// printf("%x",secret[i]);
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// printf( " : secret\n");
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//sample kdf prog
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EVP_PKEY_CTX * pctx;
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//uint8_t * OUT = calloc(1,sizeof(uint8_t)*KDF_KEY_SIZE);
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//size_t keylen = KDF_KEY_SIZE;
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uint8_t salt[32] = {0x31,0xe2,0x3e,0xcc,0x28,0xc5,0x7b,0xbb,0x38,0x7d,0xe6,0x66,0xbb,
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0xbe,0x67,0x0a,0xf8,0xf3,0x92,0x0e,0xba,0x68,0xd1,0x56,0xea,0x34,0x3f,0xbc,0x4f,
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0xf1,0xd9,0x1e};
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pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL); //..new_id() allocates pub key alg to ctx
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if(EVP_PKEY_derive_init(pctx) <= 0)
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perror("pkey init failed:");
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// if (EVP_PKEY_CTX_hkdf_mode(pctx,EVP_PKEY_HKDEF_MODE_EXPAND_ONLY ) <= 0)
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//perror("set message mode failed:");
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if (EVP_PKEY_CTX_set_hkdf_md(pctx, EVP_sha256()) <= 0)
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perror("set message digest failed:");
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if (EVP_PKEY_CTX_set1_hkdf_salt(pctx, salt, sizeof(salt)) <= 0)
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perror("set salt failed:");
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if (EVP_PKEY_CTX_set1_hkdf_key(pctx, secret, secret_len) <= 0)
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perror("set secret failed:");
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if (EVP_PKEY_CTX_add1_hkdf_info(pctx, passphrase, pass_len) <= 0)
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perror("set label failed:");
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if (EVP_PKEY_derive(pctx, out, out_len) <= 0)
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perror("pkey derivation failed:");
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// for(int i = 0; i <= KDF_KEY_SIZE; i++)
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// printf("%x,",out[i]);
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// printf( ": OUT\n");
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EVP_PKEY_CTX_free(pctx);
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return 1;
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} |