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RFC 4634, "US Secure Hash Algorithms (SHA and HMAC-SHA)", July 2006

Note: This RFC has been obsoleted by RFC 6234

Source of RFC: IETF - NON WORKING GROUP
Area Assignment: sec

Errata ID: 2418
Status: Held for Document Update
Type: Technical
Publication Format(s) : TEXT
Reported By: Alfred Hoenes
Date Reported: 2006-08-13
Held for Document Update by: Sean Turner
Date Held: 2010-08-06

Section 8.2.1 says: 

Near the top of page 25, there is the code:

/*
 * add "length" to the length
 */
static uint32_t addTemp;
#define SHA1AddLength(context, length)                     \
    (addTemp = (context)->Length_Low,                      \
     (context)->Corrupted =                                \
        (((context)->Length_Low += (length)) < addTemp) && \
        (++(context)->Length_High == 0) ? 1 : 0)

It should say:

It should say (modifying the last line):

/*
 * add "length" to the length
 */
static uint32_t addTemp;
#define SHA1AddLength(context, length)                     \
    (addTemp = (context)->Length_Low,                      \
     (context)->Corrupted =                                \
        (((context)->Length_Low += (length)) < addTemp) && \
        (++(context)->Length_High == 0) ? shaInputTooLong : shaSuccess )

Notes:

As can be found on page 19 (upper half), sha.h contains:

#ifndef _SHA_enum_
#define _SHA_enum_
/*
* All SHA functions return one of these values.
*/
enum {
shaSuccess = 0,
shaNull, /* Null pointer parameter */
shaInputTooLong, /* input data too long */
shaStateError, /* called Input after FinalBits or Result */
shaBadParam /* passed a bad parameter */
};
#endif /* _SHA_enum_ */

This leaves it to the compiler to assign values, but ordinarily,
shaNull will be assigned the value 1,
shaInputTooLong will be assigned the value 2, etc. ...

The value assigned to context->Corrupted in the #define listed
above will later on repeatedly be used to generate return values,
via code lines:
return context->Corrupted;

These return values are expected to be SHA_enum values.
In the case where Corrupted gets assigned the value 0, it apparently
was intended to eventually get the return value 'shaSuccess', and
in the case where Corrupted gets assigned the value 1, it apparently
was intended to eventually get the return value 'shaInputTooLong'.
With the code shown above, the former will work, but the latter
will usually *not* work as intended.

To obtain portable source code behaving as documented, the proposed
change has to be applied.

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