Baseband TEA Keys

The baseband generates TEA keys based of the CHIPID and NORID.

Key A Generation

//return unique phone key (key A), this key is used for security zone encryption/decryption
void get_keyA(u8 *A){

SHA1Context ctx; SHA1Reset(&ctx); SHA1Input(&ctx,dep1_norid,0x10); SHA1Input(&ctx,dep2_chipid,0x10); SHA1Result(&ctx); memcpy(A,(u8*)ctx.Message_Digest,0x14);

}

NCK Key Generation

//ulc_mix_lock_unlock_key((u8*)A,(u8*)ctx.Message_Digest,dep1_norid,dep2_chipid,(u8*)B);
void ulc_mix_lock_unlock_key(u8 *keyA, u8 *keyNCK,u8 *norid,u8 *chipid,u8 *keyB){
	u8 out_iv[8];
	tea_3_round_encipher(norid,keyNCK,keyA,keyB,out_iv);		//norid, keyNCK, SP+4, SP+0x14, SP+0x34
	tea_3_round_encipher(chipid,keyNCK,out_iv,keyB+8,out_iv); //chipid, keyNCK, SP+4, SP+0x14, SP+0x34
}
// auxilary function for nck key generation
void tea_3_round_encipher(u8 *in,u8 *key,u8 *iv,u8 *out,u8 *out_iv){
	u32 tmpin[2],nexttea[2];
	tea_encipher((u32*)in,tmpin,(u32*)key);
 	nexttea[0] = tmpin[0]^((u32*)iv)[0];
	nexttea[1] = tmpin[1]^((u32*)iv)[1];
	tea_encipher(nexttea,(u32*)out,(u32*)key);
	nexttea[0] = tmpin[0]^((u32*)out)[0];
	nexttea[1] = tmpin[1]^((u32*)out)[1];
	tea_encipher(nexttea,(u32*)out_iv,(u32*)key);
}