initial commit

src/encryption.c

@@ -0,0 +1,247 @@
+#include "encryption.h"
+
+int pcpdecrypt(char *id, int useid, char *infile, char *outfile, char *passwd) {
+  FILE *in = NULL;
+  FILE *out = NULL;
+  pcp_pubkey_t *public = NULL;
+  pcp_key_t *secret = NULL;
+
+  if(useid) {
+    HASH_FIND_STR(pcpkey_hash, id, secret);
+    if(secret == NULL) {
+      fatal("Could not find a secret key with id 0x%s in vault %s!\n",
+	    id, vault->filename);
+      goto errde3;
+    }
+  }
+  else {
+    secret = pcp_find_primary_secret();
+    if(secret == NULL) {
+      fatal("Could not find a secret key in vault %s!\n", id, vault->filename);
+      goto errde3;
+    }
+  }
+
+  if(infile == NULL)
+    in = stdin;
+  else {
+    if((in = fopen(infile, "rb")) == NULL) {
+      fatal("Could not open input file %s\n", infile);
+      goto errde2;
+    }
+  }
+
+  if(outfile == NULL)
+    out = stdout;
+  else {
+    if((out = fopen(outfile, "wb+")) == NULL) {
+      fatal("Could not open output file %s\n", outfile);
+      goto errde2;
+    }
+  }
+
+  if(secret->secret[0] == 0) {
+    // encrypted, decrypt it
+    char *passphrase;
+    if(passwd == NULL) {
+      pcp_readpass(&passphrase,
+		   "Enter passphrase to decrypt your secret key", NULL, 1);
+    }
+    else {
+      passphrase = ucmalloc(strlen(passwd)+1);
+      strncpy(passphrase, passwd, strlen(passwd)+1);
+    }
+
+    secret = pcpkey_decrypt(secret, passphrase);
+    if(secret == NULL)
+      goto errde3;
+  }
+
+  char *encoded = pcp_readz85file(in);
+  if(encoded == NULL)
+    goto errde2;
+
+  size_t clen;
+  unsigned char *combined = pcp_z85_decode((char *)encoded, &clen);
+
+  if(combined == NULL)
+    goto errde1;
+
+  char *senderid = ucmalloc(17);
+  memcpy(senderid, combined, 16);
+  senderid[16] = '\0';
+
+  HASH_FIND_STR(pcppubkey_hash, senderid, public);
+  if(public == NULL) {
+    fatal("Could not find a public key with id 0x%s in vault %s!\n",
+	  senderid, vault->filename);
+    goto errde0;
+  }
+
+  if(debug) {
+    fprintf(stderr, "Using secret key:\n");
+    pcpkey_printshortinfo(secret);
+    fprintf(stderr, "Using publickey:\n");
+    pcppubkey_printshortinfo(public);
+  }
+
+  unsigned char *encrypted = ucmalloc(clen - 16);
+  memcpy(encrypted, &combined[16], clen - 16);
+
+  size_t dlen;
+  unsigned char *decrypted = pcp_box_decrypt(secret, public,
+					     encrypted, clen - 16, &dlen);
+
+  if(decrypted != NULL) {
+    fwrite(decrypted, dlen, 1, out);
+    fclose(out);
+    if(ferror(out) != 0) {
+      fatal("Failed to write decrypted output!\n");
+    }
+    free(decrypted);
+  }
+
+  fprintf(stderr, "Decrypted %d bytes from 0x%s successfully\n",
+	  (int)dlen, senderid);
+
+  free(encrypted);
+
+ errde0:
+  free(senderid);
+  free(combined);
+
+ errde1:
+  free(encoded);
+
+ errde2:
+
+ errde3:
+  return 1;
+}
+
+
+
+int pcpencrypt(char *id, char *infile, char *outfile, char *passwd) {
+  FILE *in = NULL;
+  FILE *out = NULL;
+  pcp_pubkey_t *public = NULL;
+  pcp_key_t *secret = NULL;
+
+  // look if we've got that key
+  HASH_FIND_STR(pcppubkey_hash, id, public);
+  if(public == NULL) {
+    fatal("Could not find a public key with id 0x%s in vault %s!\n",
+	  id, vault->filename);
+    goto erren3;
+  }
+
+  secret = pcp_find_primary_secret();
+  if(secret == NULL) {
+    fatal("Could not find a secret key in vault %s!\n", id, vault->filename);
+    goto erren2;
+  }
+
+  if(infile == NULL)
+    in = stdin;
+  else {
+    if((in = fopen(infile, "rb")) == NULL) {
+      fatal("Could not open input file %s\n", infile);
+      goto erren1;
+    }
+  }
+
+  if(outfile == NULL)
+    out = stdout;
+  else {
+    if((out = fopen(outfile, "wb+")) == NULL) {
+      fatal("Could not open output file %s\n", outfile);
+      goto erren1;
+    }
+  }
+
+  if(secret->secret[0] == 0) {
+    // encrypted, decrypt it
+    char *passphrase;
+    if(passwd == NULL) {
+      pcp_readpass(&passphrase,
+		   "Enter passphrase to decrypt your secret key", NULL, 1);
+    }
+    else {
+      passphrase = ucmalloc(strlen(passwd)+1);
+      strncpy(passphrase, passwd, strlen(passwd)+1);
+    }
+    secret = pcpkey_decrypt(secret, passphrase);
+    if(secret == NULL)
+      goto erren2;
+  }
+
+  if(debug) {
+    fprintf(stderr, "Using secret key:\n");
+    pcpkey_printshortinfo(secret);
+    fprintf(stderr, "Using publickey:\n");
+    pcppubkey_printshortinfo(public);
+  }
+
+  unsigned char *input = NULL;
+  size_t inputBufSize = 0;
+  unsigned char byte[1];
+  
+  while(!feof(in)) {
+    if(!fread(&byte, 1, 1, in))
+      break;
+    unsigned char *tmp = realloc(input, inputBufSize + 1);
+    input = tmp;
+    memmove(&input[inputBufSize], byte, 1);
+    inputBufSize ++;
+  }
+  fclose(in);
+
+  if(inputBufSize == 0) {
+    fatal("Input file is empty!\n");
+    goto erren1;
+  }
+
+  size_t ciphersize;
+  unsigned char *cipher = pcp_box_encrypt(secret, public, input,
+					  inputBufSize, &ciphersize);
+  if(cipher == NULL)
+    goto erren1;
+
+  size_t zlen;
+  size_t clen = ciphersize + 16;
+  unsigned char *combined = ucmalloc(clen);
+  memcpy(combined, secret->id, 16);
+  memcpy(&combined[16], cipher, clen - 16);
+
+  // combined consists of:
+  // keyid|nonce|cipher
+  char *encoded = pcp_z85_encode(combined, clen, &zlen);
+
+  if(encoded == NULL)
+    goto erren0;
+  
+  fprintf(out, "%s\n%s\n%s\n", PCP_ENFILE_HEADER, encoded, PCP_ENFILE_FOOTER);
+  if(ferror(out) != 0) {
+    fatal("Failed to write encrypted output!\n");
+  }
+
+  fprintf(stderr, "Encrypted %d bytes for 0x%s successfully\n",
+	  (int)inputBufSize, id);
+
+  fclose(out);
+  free(encoded);
+  free(combined);
+  free(cipher);
+  return 0;
+
+ erren0:
+  free(cipher);
+
+ erren1:
+
+ erren2:
+
+ erren3:
+
+  return 1;
+}