Add a debugging option to PKCS#5 v2.0 key generation function.
diff --git a/CHANGES b/CHANGES
index 94cae7d..fc8e884 100644
--- a/CHANGES
+++ b/CHANGES
@@ -4,6 +4,11 @@
Changes between 0.9.3a and 0.9.4
+ *) Add a debugging option to PKCS#5 v2 key generation function: when
+ you #define DEBUG_PKCS5V2 passwords, salts, iteration counts and
+ derived keys are printed to stderr.
+ [Steve Henson]
+
*) Copy the flags in ASN1_STRING_dup().
[Roman E. Pavlov <pre@mo.msk.ru>]
diff --git a/crypto/evp/p5_crpt2.c b/crypto/evp/p5_crpt2.c
index dd23bd2..2de3a2c 100644
--- a/crypto/evp/p5_crpt2.c
+++ b/crypto/evp/p5_crpt2.c
@@ -55,7 +55,6 @@
* Hudson (tjh@cryptsoft.com).
*
*/
-#if !defined(NO_HMAC) && !defined(NO_SHA)
#include <stdio.h>
#include <stdlib.h>
#include <openssl/x509.h>
@@ -63,6 +62,13 @@
#include <openssl/hmac.h>
#include "cryptlib.h"
+/* set this to print out info about the keygen algorithm */
+/* #define DEBUG_PKCS5V2 */
+
+#ifdef DEBUG_PKCS5V2
+ static void h__dump (const unsigned char *p, int len);
+#endif
+
/* This is an implementation of PKCS#5 v2.0 password based encryption key
* derivation function PBKDF2 using the only currently defined function HMAC
* with SHA1. Verified against test vectors posted by Peter Gutmann
@@ -74,14 +80,15 @@
int keylen, unsigned char *out)
{
unsigned char digtmp[SHA_DIGEST_LENGTH], *p, itmp[4];
- int cplen, j, k;
+ int cplen, j, k, tkeylen;
unsigned long i = 1;
HMAC_CTX hctx;
p = out;
+ tkeylen = keylen;
if(passlen == -1) passlen = strlen(pass);
- while(keylen) {
- if(keylen > SHA_DIGEST_LENGTH) cplen = SHA_DIGEST_LENGTH;
- else cplen = keylen;
+ while(tkeylen) {
+ if(tkeylen > SHA_DIGEST_LENGTH) cplen = SHA_DIGEST_LENGTH;
+ else cplen = tkeylen;
/* We are unlikely to ever use more than 256 blocks (5120 bits!)
* but just in case...
*/
@@ -99,11 +106,20 @@
digtmp, SHA_DIGEST_LENGTH, digtmp, NULL);
for(k = 0; k < cplen; k++) p[k] ^= digtmp[k];
}
- keylen-= cplen;
+ tkeylen-= cplen;
i++;
p+= cplen;
}
HMAC_cleanup(&hctx);
+#ifdef DEBUG_PKCS5V2
+ fprintf(stderr, "Password:\n");
+ h__dump (pass, passlen);
+ fprintf(stderr, "Salt:\n");
+ h__dump (salt, saltlen);
+ fprintf(stderr, "Iteration count %d\n", iter);
+ fprintf(stderr, "Key:\n");
+ h__dump (out, keylen);
+#endif
return 1;
}
@@ -219,4 +235,12 @@
PBKDF2PARAM_free(kdf);
return 0;
}
+
+#ifdef DEBUG_PKCS5V2
+static void h__dump (const unsigned char *p, int len)
+{
+ for (; len --; p++) fprintf(stderr, "%02X ", *p);
+ fprintf(stderr, "\n");
+}
#endif
+
