SHA-1 hash for LoadRunner

One of my colleagues at work was testing a solution that obfuscated passwords using the SHA1 algorithm, and was looking for a suitable solution to replicate this with LoadRunner. As I’ve used SHA1 before for other things, I promised to look around and see if I could help out.

As it turns out a suitable source was found and I made the necessary changes to the code to make it work in LoadRunner. A big thank you to Paul E. Jones for providing a free SHA1 implementation.

I created an include file names “lr_sha1.c” that can easily be included in any C based LoadRunner script or VUser type.

Example of usage (vuser_init.c):

#include "lr_sha1.c"
vuser_init()
{
	//
	// HASH the string "The quick brown fox jumps over the lazy dog",
	// The result should be "2FD4E1C67A2D28FCED849EE1BB76E7391B93EB12"
	//
	sha1_hash("The quick brown fox jumps over the lazy dog", "_sha1");

	lr_output_message( "SHA1 Hash: %s", lr_eval_string("{_sha1}") );

	return 0;
}

And here is the lr_sha1.c file:

/*
 *****************************************************************************
 *
 *  March 2010
 *
 *    Small changes by Kim Sandell to make the source work in LoadRunner
 *    - Changed "const unsigned char" to "const char" in function params
 *    - Combined sha1.h and sha1.c into one file (for ease of use in LR)
 *    - Added sha1_hash() function to ease use in LR
 *    - Included Paul's license in comments
 *
 *****************************************************************************
 *
 *  Freeware Public License (FPL)
 *
 *  This software is licensed as "freeware."  Permission to distribute
 *  this software in source and binary forms, including incorporation
 *  into other products, is hereby granted without a fee.  THIS SOFTWARE
 *  IS PROVIDED 'AS IS' AND WITHOUT ANY EXPRESSED OR IMPLIED WARRANTIES,
 *  INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 *  AND FITNESS FOR A PARTICULAR PURPOSE.  THE AUTHOR SHALL NOT BE HELD
 *  LIABLE FOR ANY DAMAGES RESULTING FROM THE USE OF THIS SOFTWARE, EITHER
 *  DIRECTLY OR INDIRECTLY, INCLUDING, BUT NOT LIMITED TO, LOSS OF DATA
 *  OR DATA BEING RENDERED INACCURATE.
 *
 *****************************************************************************
 *
 *  sha1.h
 *
 *  Copyright (C) 1998, 2009
 *  Paul E. Jones <paulej@packetizer.com>
 *  All Rights Reserved
 *
 *****************************************************************************
 *  $Id: sha1.h 12 2009-06-22 19:34:25Z paulej $
 *****************************************************************************
 *
 *  Description:
 *      This class implements the Secure Hashing Standard as defined
 *      in FIPS PUB 180-1 published April 17, 1995.
 *
 *      Many of the variable names in the SHA1Context, especially the
 *      single character names, were used because those were the names
 *      used in the publication.
 *
*/

#ifndef _SHA1_H_
#define _SHA1_H_

/*
 *  This structure will hold context information for the hashing
 *  operation
 */
typedef struct SHA1Context
{
 unsigned Message_Digest[5];       /* Message Digest (output)          */
 unsigned Length_Low;              /* Message length in bits           */
 unsigned Length_High;             /* Message length in bits           */
 unsigned char Message_Block[64];  /* 512-bit message blocks      */
 int Message_Block_Index;          /* Index into message block array   */
 int Computed;                     /* Is the digest computed?          */
 int Corrupted;                    /* Is the message digest corruped?  */
} SHA1Context;

/*
 *  Function Prototypes
 */
void SHA1Reset(SHA1Context *);
int SHA1Result(SHA1Context *);
void SHA1Input( SHA1Context *,
 const char *,
 unsigned);
#endif

/*
 *****************************************************************************
 *
 *  sha1.c
 *
 *  Copyright (C) 1998, 2009
 *  Paul E. Jones <paulej@packetizer.com>
 *  All Rights Reserved
 *
 *****************************************************************************
 *  $Id: sha1.c 12 2009-06-22 19:34:25Z paulej $
 *****************************************************************************
 *
 *  Description:
 *      This file implements the Secure Hashing Standard as defined
 *      in FIPS PUB 180-1 published April 17, 1995.
 *
 *      The Secure Hashing Standard, which uses the Secure Hashing
 *      Algorithm (SHA), produces a 160-bit message digest for a
 *      given data stream.  In theory, it is highly improbable that
 *      two messages will produce the same message digest.  Therefore,
 *      this algorithm can serve as a means of providing a "fingerprint"
 *      for a message.
 *
 *  Portability Issues:
 *      SHA-1 is defined in terms of 32-bit "words".  This code was
 *      written with the expectation that the processor has at least
 *      a 32-bit machine word size.  If the machine word size is larger,
 *      the code should still function properly.  One caveat to that
 *      is that the input functions taking characters and character
 *      arrays assume that only 8 bits of information are stored in each
 *      character.
 *
 *  Caveats:
 *      SHA-1 is designed to work with messages less than 2^64 bits
 *      long. Although SHA-1 allows a message digest to be generated for
 *      messages of any number of bits less than 2^64, this
 *      implementation only works with messages with a length that is a
 *      multiple of the size of an 8-bit character.
 *
 *****************************************************************************
 */

/*
 *  Define the circular shift macro
 */
#define SHA1CircularShift(bits,word) \
 ((((word) << (bits)) & 0xFFFFFFFF) | \
 ((word) >> (32-(bits))))

/* Function prototypes */
void SHA1ProcessMessageBlock(SHA1Context *);
void SHA1PadMessage(SHA1Context *);

/*
 *  SHA1Reset
 *
 *  Description:
 *      This function will initialize the SHA1Context in preparation
 *      for computing a new message digest.
 *
 *  Parameters:
 *      context: [in/out]
 *          The context to reset.
 *
 *  Returns:
 *      Nothing.
 *
 *  Comments:
 *
 */
void SHA1Reset(SHA1Context *context)
{
 context->Length_Low             = 0;
 context->Length_High            = 0;
 context->Message_Block_Index    = 0;

 context->Message_Digest[0]      = 0x67452301;
 context->Message_Digest[1]      = 0xEFCDAB89;
 context->Message_Digest[2]      = 0x98BADCFE;
 context->Message_Digest[3]      = 0x10325476;
 context->Message_Digest[4]      = 0xC3D2E1F0;

 context->Computed   = 0;
 context->Corrupted  = 0;
}

/*
 *  SHA1Result
 *
 *  Description:
 *      This function will return the 160-bit message digest into the
 *      Message_Digest array within the SHA1Context provided
 *
 *  Parameters:
 *      context: [in/out]
 *          The context to use to calculate the SHA-1 hash.
 *
 *  Returns:
 *      1 if successful, 0 if it failed.
 *
 *  Comments:
 *
 */
int SHA1Result(SHA1Context *context)
{

 if (context->Corrupted)
 {
 return 0;
 }

 if (!context->Computed)
 {
 SHA1PadMessage(context);
 context->Computed = 1;
 }

 return 1;
}

/*
 *  SHA1Input
 *
 *  Description:
 *      This function accepts an array of octets as the next portion of
 *      the message.
 *
 *  Parameters:
 *      context: [in/out]
 *          The SHA-1 context to update
 *      message_array: [in]
 *          An array of characters representing the next portion of the
 *          message.
 *      length: [in]
 *          The length of the message in message_array
 *
 *  Returns:
 *      Nothing.
 *
 *  Comments:
 *
 */
void SHA1Input(     SHA1Context  *context,
 const char   *message_array,
 unsigned     length)
{
 if (!length)
 {
 return;
 }

 if (context->Computed || context->Corrupted)
 {
 context->Corrupted = 1;
 return;
 }

 while(length-- && !context->Corrupted)
 {
 context->Message_Block[context->Message_Block_Index++] =
 (*message_array & 0xFF);

 context->Length_Low += 8;
 /* Force it to 32 bits */
 context->Length_Low &= 0xFFFFFFFF;
 if (context->Length_Low == 0)
 {
 context->Length_High++;
 /* Force it to 32 bits */
 context->Length_High &= 0xFFFFFFFF;
 if (context->Length_High == 0)
 {
 /* Message is too long */
 context->Corrupted = 1;
 }
 }

 if (context->Message_Block_Index == 64)
 {
 SHA1ProcessMessageBlock(context);
 }

 message_array++;
 }
}

/*
 *  SHA1ProcessMessageBlock
 *
 *  Description:
 *      This function will process the next 512 bits of the message
 *      stored in the Message_Block array.
 *
 *  Parameters:
 *      None.
 *
 *  Returns:
 *      Nothing.
 *
 *  Comments:
 *      Many of the variable names in the SHAContext, especially the
 *      single character names, were used because those were the names
 *      used in the publication.
 *
 *
 */
void SHA1ProcessMessageBlock(SHA1Context *context)
{
 const unsigned K[] =            /* Constants defined in SHA-1   */
 {
 0x5A827999,
 0x6ED9EBA1,
 0x8F1BBCDC,
 0xCA62C1D6
 };
 int         t;                  /* Loop counter                 */
 unsigned    temp;               /* Temporary word value         */
 unsigned    W[80];              /* Word sequence                */
 unsigned    A, B, C, D, E;      /* Word buffers                 */

 /*
 *  Initialize the first 16 words in the array W
 */
 for(t = 0; t < 16; t++)
 {
 W[t] = ((unsigned) context->Message_Block[t * 4]) << 24;
 W[t] |= ((unsigned) context->Message_Block[t * 4 + 1]) << 16;
 W[t] |= ((unsigned) context->Message_Block[t * 4 + 2]) << 8;
 W[t] |= ((unsigned) context->Message_Block[t * 4 + 3]);
 }

 for(t = 16; t < 80; t++)
 {
 W[t] = SHA1CircularShift(1,W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16]);
 }

 A = context->Message_Digest[0];
 B = context->Message_Digest[1];
 C = context->Message_Digest[2];
 D = context->Message_Digest[3];
 E = context->Message_Digest[4];

 for(t = 0; t < 20; t++)
 {
 temp =  SHA1CircularShift(5,A) +
 ((B & C) | ((~B) & D)) + E + W[t] + K[0];
 temp &= 0xFFFFFFFF;
 E = D;
 D = C;
 C = SHA1CircularShift(30,B);
 B = A;
 A = temp;
 }

 for(t = 20; t < 40; t++)
 {
 temp = SHA1CircularShift(5,A) + (B ^ C ^ D) + E + W[t] + K[1];
 temp &= 0xFFFFFFFF;
 E = D;
 D = C;
 C = SHA1CircularShift(30,B);
 B = A;
 A = temp;
 }

 for(t = 40; t < 60; t++)
 {
 temp = SHA1CircularShift(5,A) +
 ((B & C) | (B & D) | (C & D)) + E + W[t] + K[2];
 temp &= 0xFFFFFFFF;
 E = D;
 D = C;
 C = SHA1CircularShift(30,B);
 B = A;
 A = temp;
 }

 for(t = 60; t < 80; t++)
 {
 temp = SHA1CircularShift(5,A) + (B ^ C ^ D) + E + W[t] + K[3];
 temp &= 0xFFFFFFFF;
 E = D;
 D = C;
 C = SHA1CircularShift(30,B);
 B = A;
 A = temp;
 }

 context->Message_Digest[0] =
 (context->Message_Digest[0] + A) & 0xFFFFFFFF;
 context->Message_Digest[1] =
 (context->Message_Digest[1] + B) & 0xFFFFFFFF;
 context->Message_Digest[2] =
 (context->Message_Digest[2] + C) & 0xFFFFFFFF;
 context->Message_Digest[3] =
 (context->Message_Digest[3] + D) & 0xFFFFFFFF;
 context->Message_Digest[4] =
 (context->Message_Digest[4] + E) & 0xFFFFFFFF;

 context->Message_Block_Index = 0;
}

/*
 *  SHA1PadMessage
 *
 *  Description:
 *      According to the standard, the message must be padded to an even
 *      512 bits.  The first padding bit must be a '1'.  The last 64
 *      bits represent the length of the original message.  All bits in
 *      between should be 0.  This function will pad the message
 *      according to those rules by filling the Message_Block array
 *      accordingly.  It will also call SHA1ProcessMessageBlock()
 *      appropriately.  When it returns, it can be assumed that the
 *      message digest has been computed.
 *
 *  Parameters:
 *      context: [in/out]
 *          The context to pad
 *
 *  Returns:
 *      Nothing.
 *
 *  Comments:
 *
 */
void SHA1PadMessage(SHA1Context *context)
{
 /*
 *  Check to see if the current message block is too small to hold
 *  the initial padding bits and length.  If so, we will pad the
 *  block, process it, and then continue padding into a second
 *  block.
 */
 if (context->Message_Block_Index > 55)
 {
 context->Message_Block[context->Message_Block_Index++] = 0x80;
 while(context->Message_Block_Index < 64)
 {
 context->Message_Block[context->Message_Block_Index++] = 0;
 }

 SHA1ProcessMessageBlock(context);

 while(context->Message_Block_Index < 56)
 {
 context->Message_Block[context->Message_Block_Index++] = 0;
 }
 }
 else
 {
 context->Message_Block[context->Message_Block_Index++] = 0x80;
 while(context->Message_Block_Index < 56)
 {
 context->Message_Block[context->Message_Block_Index++] = 0;
 }
 }

 /*
 *  Store the message length as the last 8 octets
 */
 context->Message_Block[56] = (context->Length_High >> 24 ) & 0xFF;
 context->Message_Block[57] = (context->Length_High >> 16 ) & 0xFF;
 context->Message_Block[58] = (context->Length_High >> 8 ) & 0xFF;
 context->Message_Block[59] = (context->Length_High) & 0xFF;
 context->Message_Block[60] = (context->Length_Low >> 24 ) & 0xFF;
 context->Message_Block[61] = (context->Length_Low >> 16 ) & 0xFF;
 context->Message_Block[62] = (context->Length_Low >> 8 ) & 0xFF;
 context->Message_Block[63] = (context->Length_Low) & 0xFF;

 SHA1ProcessMessageBlock(context);
}

int sha1_hash(const char *source, char *lrvar)
// ----------------------------------------------------------------------------
// HASH:es a string with SHA1 and stores resulting hash in lrvar variable
//
// Parameters:
//        source    Pointer to source string to HASH
//        lrvar     LR variable where base64 encoded string is stored
//
// Result
//        -1        Error
//        >0        Success. Actual value is length of HASH string
//
// Example:
//        sha1_hash( "abc", "sha1" )  // sha1=A9993E364706816ABA3E25717850C26C9CD0D89D
// ----------------------------------------------------------------------------
{
 SHA1Context sha;
 char buf[128];

 SHA1Reset(&sha);
 SHA1Input(&sha, source, strlen(source));

 if (!SHA1Result(&sha))
 {
 lr_error_message("SHA1 ERROR: Could not compute message digest");

 return -1;
 }
 else
 {
 // Clear Buffer
 memset(buf,0,sizeof(buf));

 // Store HASH in buffer
 sprintf(buf, "%08X%08X%08X%08X%08X", sha.Message_Digest[0],sha.Message_Digest[1],
 sha.Message_Digest[2],sha.Message_Digest[3],sha.Message_Digest[4]);

 // Save to LR variable
 lr_save_string(buf, lrvar);

 // Return length of string (>0 = success)
 return strlen(buf);
 }
}