* Addition of support for SHA1 to SHA512 needed for future additions to

     Alpine. The code is taken and adapted from code in RFC 4634.

1 files changed, 427 insertions, 0 deletions

diff --git a/imap/src/c-client/sha1.c b/imap/src/c-client/sha1.c
new file mode 100644
index 00000000..6ecfceff
--- /dev/null
+++ b/imap/src/c-client/sha1.c
@@ -0,0 +1,427 @@
+/**************************** sha1.c ****************************/
+/******************** See RFC 4634 for details ******************/
+/*
+ *  Description:
+ *      This file implements the Secure Hash Signature Standard
+ *      algorithms as defined in the National Institute of Standards
+ *      and Technology Federal Information Processing Standards
+ *      Publication (FIPS PUB) 180-1 published on April 17, 1995, 180-2
+ *      published on August 1, 2002, and the FIPS PUB 180-2 Change
+ *      Notice published on February 28, 2004.
+ *
+ *      A combined document showing all algorithms is available at
+ *              http://csrc.nist.gov/publications/fips/
+ *              fips180-2/fips180-2withchangenotice.pdf
+ *
+ *      The SHA-1 algorithm produces a 160-bit message digest for a
+ *      given data stream.  It should take about 2**n steps to find a
+ *      message with the same digest as a given message and
+ *      2**(n/2) to find any two messages with the same digest,
+ *      when n is the digest size in bits.  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
+ *      uses <stdint.h> (included via "sha.h") to define 32 and 8
+ *      bit unsigned integer types.  If your C compiler does not
+ *      support 32 bit unsigned integers, this code is not
+ *      appropriate.
+ *
+ *  Caveats:
+ *      SHA-1 is designed to work with messages less than 2^64 bits
+ *      long. This implementation uses SHA1Input() to hash the bits
+ *      that are a multiple of the size of an 8-bit character, and then
+ *      uses SHA1FinalBits() to hash the final few bits of the input.
+ */
+
+#include "sha.h"
+#include "sha-private.h"
+
+/*
+ *  Define the SHA1 circular left shift macro
+ */
+#define SHA1_ROTL(bits,word) \
+                (((word) << (bits)) | ((word) >> (32-(bits))))
+
+/*
+ * 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)
+
+/* Local Function Prototypes */
+static void SHA1Finalize(SHA1Context *context, uint8_t Pad_Byte);
+static void SHA1PadMessage(SHA1Context *, uint8_t Pad_Byte);
+static void SHA1ProcessMessageBlock(SHA1Context *);
+
+/*
+ *  SHA1Reset
+ *
+ *  Description:
+ *      This function will initialize the SHA1Context in preparation
+ *      for computing a new SHA1 message digest.
+ *
+ *  Parameters:
+ *      context: [in/out]
+ *          The context to reset.
+ *
+ *  Returns:
+ *      sha Error Code.
+ *
+ */
+int SHA1Reset(SHA1Context *context)
+{
+    if (!context)
+        return shaNull;
+
+    context->Length_Low             = 0;
+    context->Length_High            = 0;
+    context->Message_Block_Index    = 0;
+    /* Initial Hash Values: FIPS-180-2 section 5.3.1 */
+    context->Intermediate_Hash[0]   = 0x67452301;
+    context->Intermediate_Hash[1]   = 0xEFCDAB89;
+    context->Intermediate_Hash[2]   = 0x98BADCFE;
+    context->Intermediate_Hash[3]   = 0x10325476;
+    context->Intermediate_Hash[4]   = 0xC3D2E1F0;
+
+    context->Computed   = 0;
+    context->Corrupted  = 0;
+
+    return shaSuccess;
+}
+
+/*
+ *  SHA1Input
+ *
+ *  Description:
+ *      This function accepts an array of octets as the next portion
+ *      of the message.
+ *
+ *  Parameters:
+ *      context: [in/out]
+ *          The SHA 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:
+ *      sha Error Code.
+ *
+ */
+int SHA1Input(SHA1Context *context,
+    const uint8_t *message_array, unsigned length)
+{
+  if (!length)
+    return shaSuccess;
+
+  if (!context || !message_array)
+    return shaNull;
+
+  if (context->Computed) {
+    context->Corrupted = shaStateError;
+    return shaStateError;
+  }
+
+  if (context->Corrupted)
+     return context->Corrupted;
+
+  while (length-- && !context->Corrupted) {
+    context->Message_Block[context->Message_Block_Index++] =
+      (*message_array & 0xFF);
+
+    if (!SHA1AddLength(context, 8) &&
+      (context->Message_Block_Index == SHA1_Message_Block_Size))
+      SHA1ProcessMessageBlock(context);
+
+    message_array++;
+  }
+
+  return shaSuccess;
+}
+
+/*
+ * SHA1FinalBits
+ *
+ * Description:
+ *   This function will add in any final bits of the message.
+ *
+ * Parameters:
+ *   context: [in/out]
+ *     The SHA context to update
+ *   message_bits: [in]
+ *     The final bits of the message, in the upper portion of the
+ *     byte. (Use 0b###00000 instead of 0b00000### to input the
+ *     three bits ###.)
+ *   length: [in]
+ *     The number of bits in message_bits, between 1 and 7.
+ *
+ * Returns:
+ *   sha Error Code.
+ */
+int SHA1FinalBits(SHA1Context *context, const uint8_t message_bits,
+    unsigned int length)
+{
+  uint8_t masks[8] = {
+      /* 0 0b00000000 */ 0x00, /* 1 0b10000000 */ 0x80,
+      /* 2 0b11000000 */ 0xC0, /* 3 0b11100000 */ 0xE0,
+      /* 4 0b11110000 */ 0xF0, /* 5 0b11111000 */ 0xF8,
+      /* 6 0b11111100 */ 0xFC, /* 7 0b11111110 */ 0xFE
+  };
+  uint8_t markbit[8] = {
+      /* 0 0b10000000 */ 0x80, /* 1 0b01000000 */ 0x40,
+      /* 2 0b00100000 */ 0x20, /* 3 0b00010000 */ 0x10,
+      /* 4 0b00001000 */ 0x08, /* 5 0b00000100 */ 0x04,
+      /* 6 0b00000010 */ 0x02, /* 7 0b00000001 */ 0x01
+  };
+
+  if (!length)
+    return shaSuccess;
+
+  if (!context)
+    return shaNull;
+
+  if (context->Computed || (length >= 8) || (length == 0)) {
+    context->Corrupted = shaStateError;
+    return shaStateError;
+  }
+
+  if (context->Corrupted)
+     return context->Corrupted;
+
+  SHA1AddLength(context, length);
+  SHA1Finalize(context,
+    (uint8_t) ((message_bits & masks[length]) | markbit[length]));
+
+  return shaSuccess;
+}
+
+/*
+ * SHA1Result
+ *
+ * Description:
+ *   This function will return the 160-bit message digest into the
+ *   Message_Digest array provided by the caller.
+ *   NOTE: The first octet of hash is stored in the 0th element,
+ *      the last octet of hash in the 19th element.
+ *
+ * Parameters:
+ *   context: [in/out]
+ *     The context to use to calculate the SHA-1 hash.
+ *   Message_Digest: [out]
+ *     Where the digest is returned.
+ *
+ * Returns:
+ *   sha Error Code.
+ *
+ */
+int SHA1Result(SHA1Context *context,
+    uint8_t Message_Digest[SHA1HashSize])
+{
+  int i;
+
+  if (!context || !Message_Digest)
+    return shaNull;
+
+  if (context->Corrupted)
+    return context->Corrupted;
+
+  if (!context->Computed)
+    SHA1Finalize(context, 0x80);
+
+  for (i = 0; i < SHA1HashSize; ++i)
+    Message_Digest[i] = (uint8_t) (context->Intermediate_Hash[i>>2]
+              >> 8 * ( 3 - ( i & 0x03 ) ));
+
+  return shaSuccess;
+}
+
+/*
+ * SHA1Finalize
+ *
+ * Description:
+ *   This helper function finishes off the digest calculations.
+ *
+ * Parameters:
+ *   context: [in/out]
+ *     The SHA context to update
+ *   Pad_Byte: [in]
+ *     The last byte to add to the digest before the 0-padding
+ *     and length. This will contain the last bits of the message
+ *     followed by another single bit. If the message was an
+ *     exact multiple of 8-bits long, Pad_Byte will be 0x80.
+ *
+ * Returns:
+ *   sha Error Code.
+ *
+ */
+static void SHA1Finalize(SHA1Context *context, uint8_t Pad_Byte)
+{
+  int i;
+  SHA1PadMessage(context, Pad_Byte);
+  /* message may be sensitive, clear it out */
+  for (i = 0; i < SHA1_Message_Block_Size; ++i)
+    context->Message_Block[i] = 0;
+  context->Length_Low = 0;  /* and clear length */
+  context->Length_High = 0;
+  context->Computed = 1;
+}
+
+/*
+ * 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 helper function will pad the
+ *   message according to those rules by filling the Message_Block
+ *   array accordingly. When it returns, it can be assumed that the
+ *   message digest has been computed.
+ *
+ * Parameters:
+ *   context: [in/out]
+ *     The context to pad
+ *   Pad_Byte: [in]
+ *     The last byte to add to the digest before the 0-padding
+ *     and length. This will contain the last bits of the message
+ *     followed by another single bit. If the message was an
+ *     exact multiple of 8-bits long, Pad_Byte will be 0x80.
+ *
+ * Returns:
+ *   Nothing.
+ */
+static void SHA1PadMessage(SHA1Context *context, uint8_t Pad_Byte)
+{
+  /*
+   * 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 >= (SHA1_Message_Block_Size - 8)) {
+    context->Message_Block[context->Message_Block_Index++] = Pad_Byte;
+    while (context->Message_Block_Index < SHA1_Message_Block_Size)
+      context->Message_Block[context->Message_Block_Index++] = 0;
+
+    SHA1ProcessMessageBlock(context);
+  } else
+    context->Message_Block[context->Message_Block_Index++] = Pad_Byte;
+
+  while (context->Message_Block_Index < (SHA1_Message_Block_Size - 8))
+    context->Message_Block[context->Message_Block_Index++] = 0;
+
+  /*
+   * Store the message length as the last 8 octets
+   */
+  context->Message_Block[56] = (uint8_t) (context->Length_High >> 24);
+  context->Message_Block[57] = (uint8_t) (context->Length_High >> 16);
+  context->Message_Block[58] = (uint8_t) (context->Length_High >> 8);
+  context->Message_Block[59] = (uint8_t) (context->Length_High);
+  context->Message_Block[60] = (uint8_t) (context->Length_Low >> 24);
+  context->Message_Block[61] = (uint8_t) (context->Length_Low >> 16);
+  context->Message_Block[62] = (uint8_t) (context->Length_Low >> 8);
+  context->Message_Block[63] = (uint8_t) (context->Length_Low);
+
+  SHA1ProcessMessageBlock(context);
+}
+
+/*
+ * SHA1ProcessMessageBlock
+ *
+ * Description:
+ *   This helper 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 this code, especially the
+ *   single character names, were used because those were the
+ *   names used in the publication.
+ */
+static void SHA1ProcessMessageBlock(SHA1Context *context)
+{
+  /* Constants defined in FIPS-180-2, section 4.2.1 */
+  const uint32_t K[4] = {
+      0x5A827999, 0x6ED9EBA1, 0x8F1BBCDC, 0xCA62C1D6
+  };
+  int        t;               /* Loop counter */
+  uint32_t   temp;            /* Temporary word value */
+  uint32_t   W[80];           /* Word sequence */
+  uint32_t   A, B, C, D, E;   /* Word buffers */
+
+  /*
+   * Initialize the first 16 words in the array W
+   */
+  for (t = 0; t < 16; t++) {
+    W[t]  = ((uint32_t)context->Message_Block[t * 4]) << 24;
+    W[t] |= ((uint32_t)context->Message_Block[t * 4 + 1]) << 16;
+    W[t] |= ((uint32_t)context->Message_Block[t * 4 + 2]) << 8;
+    W[t] |= ((uint32_t)context->Message_Block[t * 4 + 3]);
+  }
+
+  for (t = 16; t < 80; t++)
+    W[t] = SHA1_ROTL(1, W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16]);
+
+  A = context->Intermediate_Hash[0];
+  B = context->Intermediate_Hash[1];
+  C = context->Intermediate_Hash[2];
+  D = context->Intermediate_Hash[3];
+  E = context->Intermediate_Hash[4];
+
+  for (t = 0; t < 20; t++) {
+    temp = SHA1_ROTL(5,A) + SHA_Ch(B, C, D) + E + W[t] + K[0];
+    E = D;
+    D = C;
+    C = SHA1_ROTL(30,B);
+    B = A;
+    A = temp;
+  }
+
+  for (t = 20; t < 40; t++) {
+    temp = SHA1_ROTL(5,A) + SHA_Parity(B, C, D) + E + W[t] + K[1];
+    E = D;
+    D = C;
+    C = SHA1_ROTL(30,B);
+    B = A;
+    A = temp;
+  }
+
+  for (t = 40; t < 60; t++) {
+    temp = SHA1_ROTL(5,A) + SHA_Maj(B, C, D) + E + W[t] + K[2];
+    E = D;
+    D = C;
+    C = SHA1_ROTL(30,B);
+    B = A;
+    A = temp;
+  }
+
+  for (t = 60; t < 80; t++) {
+    temp = SHA1_ROTL(5,A) + SHA_Parity(B, C, D) + E + W[t] + K[3];
+    E = D;
+    D = C;
+    C = SHA1_ROTL(30,B);
+    B = A;
+    A = temp;
+  }
+
+  context->Intermediate_Hash[0] += A;
+  context->Intermediate_Hash[1] += B;
+  context->Intermediate_Hash[2] += C;
+  context->Intermediate_Hash[3] += D;
+  context->Intermediate_Hash[4] += E;
+
+  context->Message_Block_Index = 0;
+}
+