/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/* Thanks to Thomas Pornin for the ideas how to implement the constat time

 * binary multiplication. */

#ifdef FREEBL_NO_DEPEND

#include "stubs.h"

#endif

#include "blapi.h"

#include "blapii.h"

#include "blapit.h"

#include "ctr.h"

#include "gcm.h"

#include "pkcs11t.h"

#include "platform-gcm.h"

#include "prtypes.h"

#include "secerr.h"

#include <limits.h>

#if defined(__ARM_NEON) || defined(__ARM_NEON__)

#include <arm_neon.h>

#endif

/* Forward declarations for platform-specific implementation of GHASH. */

PRBool platform_ghash_support();

SECStatus gcm_HashInit_hw(gcmHashContext *ghash);

SECStatus gcm_HashWrite_hw(gcmHashContext *ghash, unsigned char *outbuf);

SECStatus gcm_HashMult_hw(gcmHashContext *ghash, const unsigned char *buf,

                          unsigned int count);

SECStatus gcm_HashZeroX_hw(gcmHashContext *ghash);

SECStatus gcm_HashMult_sftw(gcmHashContext *ghash, const unsigned char *buf,

                            unsigned int count);

/* Stub definitions if we aren't linking a platform-specific ghash */

#if !defined(HAVE_PLATFORM_GHASH)

PRBool

platform_ghash_support()

{

    return PR_FALSE;

}

SECStatus

gcm_HashWrite_hw(gcmHashContext *ghash, unsigned char *outbuf)

{

    PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);

    return SECFailure;

}

SECStatus

gcm_HashMult_hw(gcmHashContext *ghash, const unsigned char *buf,

                unsigned int count)

{

    PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);

    return SECFailure;

}

SECStatus

gcm_HashInit_hw(gcmHashContext *ghash)

{

    PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);

    return SECFailure;

}

SECStatus

gcm_HashZeroX_hw(gcmHashContext *ghash)

{

    PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);

    return SECFailure;

}

#endif /* !HAVE_PLATFORM_GHASH */

/* Stub definitions if we aren't linking a platform-specific GCM */

#if !defined(HAVE_PLATFORM_GCM)

PRBool

platform_gcm_support()

{

    return PR_FALSE;

}

struct platform_AES_GCMContext;

SECStatus platform_aes_gcmInitCounter(platform_AES_GCMContext *gcm,

                                      const unsigned char *iv,

                                      unsigned long ivLen, unsigned long tagBits,

                                      const unsigned char *aad, unsigned long aadLen);

platform_AES_GCMContext *

platform_AES_GCM_CreateContext(void *context,

                               freeblCipherFunc cipher,

                               const unsigned char *params)

{

    PORT_Assert(0);

    PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);

    return NULL;

}

SECStatus

platform_aes_gcmInitCounter(platform_AES_GCMContext *gcm,

                            const unsigned char *iv, unsigned long ivLen,

                            unsigned long tagBits,

                            const unsigned char *aad, unsigned long aadLen)

{

    PORT_Assert(0);

    PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);

    return SECFailure;

}

void

platform_AES_GCM_DestroyContext(platform_AES_GCMContext *gcm, PRBool freeit)

{

    PORT_Assert(0);

    PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);

}

SECStatus

platform_AES_GCM_EncryptUpdate(platform_AES_GCMContext *gcm,

                               unsigned char *outbuf,

                               unsigned int *outlen, unsigned int maxout,

                               const unsigned char *inbuf, unsigned int inlen,

                               unsigned int blocksize)

{

    PORT_Assert(0);

    PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);

    return SECFailure;

}

SECStatus

platform_AES_GCM_DecryptUpdate(platform_AES_GCMContext *gcm,

                               unsigned char *outbuf,

                               unsigned int *outlen, unsigned int maxout,

                               const unsigned char *inbuf, unsigned int inlen,

                               unsigned int blocksize)

{

    PORT_Assert(0);

    PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);

    return SECFailure;

}

SECStatus

platform_AES_GCM_EncryptAEAD(platform_AES_GCMContext *gcm,

                             unsigned char *outbuf,

                             unsigned int *outlen, unsigned int maxout,

                             const unsigned char *inbuf, unsigned int inlen,

                             void *params, unsigned int paramLen,

                             const unsigned char *aad, unsigned int aadLen,

                             unsigned int blocksize)

{

    PORT_Assert(0);

    PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);

    return SECFailure;

}

SECStatus

platform_AES_GCM_DecryptAEAD(platform_AES_GCMContext *gcm,

                             unsigned char *outbuf,

                             unsigned int *outlen, unsigned int maxout,

                             const unsigned char *inbuf, unsigned int inlen,

                             void *params, unsigned int paramLen,

                             const unsigned char *aad, unsigned int aadLen,

                             unsigned int blocksize)

{

    PORT_Assert(0);

    PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);

    return SECFailure;

}

#endif /* !HAVE_PLATFORM_GCM */

uint64_t

get64(const unsigned char *bytes)

{

    return ((uint64_t)bytes[0]) << 56 |

           ((uint64_t)bytes[1]) << 48 |

           ((uint64_t)bytes[2]) << 40 |

           ((uint64_t)bytes[3]) << 32 |

           ((uint64_t)bytes[4]) << 24 |

           ((uint64_t)bytes[5]) << 16 |

           ((uint64_t)bytes[6]) << 8 |

           ((uint64_t)bytes[7]);

}

/* Initialize a gcmHashContext */

SECStatus

gcmHash_InitContext(gcmHashContext *ghash, const unsigned char *H, PRBool sw)

{

    SECStatus rv = SECSuccess;

    ghash->cLen = 0;

    ghash->bufLen = 0;

    PORT_Memset(ghash->counterBuf, 0, sizeof(ghash->counterBuf));

    ghash->h_low = get64(H + 8);

    ghash->h_high = get64(H);

    if (!sw && platform_ghash_support()) {

        rv = gcm_HashInit_hw(ghash);

    } else {

        /* We fall back to the software implementation if we can't use / don't

         * want to use pclmul. */

        ghash->ghash_mul = gcm_HashMult_sftw;

        ghash->x_high = ghash->x_low = 0;

        ghash->hw = PR_FALSE;

    }

    return rv;

}

#ifdef HAVE_INT128_SUPPORT

/* Binary multiplication x * y = r_high << 64 | r_low. */

void

bmul(uint64_t x, uint64_t y, uint64_t *r_high, uint64_t *r_low)

{

    uint128_t x1, x2, x3, x4, x5;

    uint128_t y1, y2, y3, y4, y5;

    uint128_t r, z;

    uint128_t m1 = (uint128_t)0x2108421084210842 << 64 | 0x1084210842108421;

    uint128_t m2 = (uint128_t)0x4210842108421084 << 64 | 0x2108421084210842;

    uint128_t m3 = (uint128_t)0x8421084210842108 << 64 | 0x4210842108421084;

    uint128_t m4 = (uint128_t)0x0842108421084210 << 64 | 0x8421084210842108;

    uint128_t m5 = (uint128_t)0x1084210842108421 << 64 | 0x0842108421084210;

    x1 = x & m1;

    y1 = y & m1;

    x2 = x & m2;

    y2 = y & m2;

    x3 = x & m3;

    y3 = y & m3;

    x4 = x & m4;

    y4 = y & m4;

    x5 = x & m5;

    y5 = y & m5;

    z = (x1 * y1) ^ (x2 * y5) ^ (x3 * y4) ^ (x4 * y3) ^ (x5 * y2);

    r = z & m1;

    z = (x1 * y2) ^ (x2 * y1) ^ (x3 * y5) ^ (x4 * y4) ^ (x5 * y3);

    r |= z & m2;

    z = (x1 * y3) ^ (x2 * y2) ^ (x3 * y1) ^ (x4 * y5) ^ (x5 * y4);

    r |= z & m3;

    z = (x1 * y4) ^ (x2 * y3) ^ (x3 * y2) ^ (x4 * y1) ^ (x5 * y5);

    r |= z & m4;

    z = (x1 * y5) ^ (x2 * y4) ^ (x3 * y3) ^ (x4 * y2) ^ (x5 * y1);

    r |= z & m5;

    *r_high = (uint64_t)(r >> 64);

    *r_low = (uint64_t)r;

}

SECStatus

gcm_HashMult_sftw(gcmHashContext *ghash, const unsigned char *buf,

                  unsigned int count)

{

    uint64_t ci_low, ci_high;

    size_t i;

    uint64_t z2_low, z2_high, z0_low, z0_high, z1a_low, z1a_high;

    uint128_t z_high = 0, z_low = 0;

    ci_low = ghash->x_low;

    ci_high = ghash->x_high;

    for (i = 0; i < count; i++, buf += 16) {

        ci_low ^= get64(buf + 8);

        ci_high ^= get64(buf);

        /* Do binary mult ghash->X = C * ghash->H (Karatsuba). */

        bmul(ci_high, ghash->h_high, &z2_high, &z2_low);

        bmul(ci_low, ghash->h_low, &z0_high, &z0_low);

        bmul(ci_high ^ ci_low, ghash->h_high ^ ghash->h_low, &z1a_high, &z1a_low);

        z1a_high ^= z2_high ^ z0_high;

        z1a_low ^= z2_low ^ z0_low;

        z_high = ((uint128_t)z2_high << 64) | (z2_low ^ z1a_high);

        z_low = (((uint128_t)z0_high << 64) | z0_low) ^ (((uint128_t)z1a_low) << 64);

        /* Shift one (multiply by x) as gcm spec is stupid. */

        z_high = (z_high << 1) | (z_low >> 127);

        z_low <<= 1;

        /* Reduce */

        z_low ^= (z_low << 127) ^ (z_low << 126) ^ (z_low << 121);

        z_high ^= z_low ^ (z_low >> 1) ^ (z_low >> 2) ^ (z_low >> 7);

        ci_low = (uint64_t)z_high;

        ci_high = (uint64_t)(z_high >> 64);

    }

    ghash->x_low = ci_low;

    ghash->x_high = ci_high;

    return SECSuccess;

}

#else

/* Binary multiplication x * y = r_high << 32 | r_low. */

void

bmul32(uint32_t x, uint32_t y, uint32_t *r_high, uint32_t *r_low)

{

    uint32_t x0, x1, x2, x3;

    uint32_t y0, y1, y2, y3;

    uint32_t m1 = (uint32_t)0x11111111;

    uint32_t m2 = (uint32_t)0x22222222;

    uint32_t m4 = (uint32_t)0x44444444;

    uint32_t m8 = (uint32_t)0x88888888;

    uint64_t z0, z1, z2, z3;

    uint64_t z;

    x0 = x & m1;

    x1 = x & m2;

    x2 = x & m4;

    x3 = x & m8;

    y0 = y & m1;

    y1 = y & m2;

    y2 = y & m4;

    y3 = y & m8;

    z0 = ((uint64_t)x0 * y0) ^ ((uint64_t)x1 * y3) ^

         ((uint64_t)x2 * y2) ^ ((uint64_t)x3 * y1);

    z1 = ((uint64_t)x0 * y1) ^ ((uint64_t)x1 * y0) ^

         ((uint64_t)x2 * y3) ^ ((uint64_t)x3 * y2);

    z2 = ((uint64_t)x0 * y2) ^ ((uint64_t)x1 * y1) ^

         ((uint64_t)x2 * y0) ^ ((uint64_t)x3 * y3);

    z3 = ((uint64_t)x0 * y3) ^ ((uint64_t)x1 * y2) ^

         ((uint64_t)x2 * y1) ^ ((uint64_t)x3 * y0);

    z0 &= ((uint64_t)m1 << 32) | m1;

    z1 &= ((uint64_t)m2 << 32) | m2;

    z2 &= ((uint64_t)m4 << 32) | m4;

    z3 &= ((uint64_t)m8 << 32) | m8;

    z = z0 | z1 | z2 | z3;

    *r_high = (uint32_t)(z >> 32);

    *r_low = (uint32_t)z;

}

SECStatus

gcm_HashMult_sftw(gcmHashContext *ghash, const unsigned char *buf,

                  unsigned int count)

{

    size_t i;

    uint64_t ci_low, ci_high;

    uint64_t z_high_h, z_high_l, z_low_h, z_low_l;

    uint32_t ci_high_h, ci_high_l, ci_low_h, ci_low_l;

    uint32_t b_a_h, b_a_l, a_a_h, a_a_l, b_b_h, b_b_l;

    uint32_t a_b_h, a_b_l, b_c_h, b_c_l, a_c_h, a_c_l, c_c_h, c_c_l;

    uint32_t ci_highXlow_h, ci_highXlow_l, c_a_h, c_a_l, c_b_h, c_b_l;

    uint32_t h_high_h = (uint32_t)(ghash->h_high >> 32);

    uint32_t h_high_l = (uint32_t)ghash->h_high;

    uint32_t h_low_h = (uint32_t)(ghash->h_low >> 32);

    uint32_t h_low_l = (uint32_t)ghash->h_low;

    uint32_t h_highXlow_h = h_high_h ^ h_low_h;

    uint32_t h_highXlow_l = h_high_l ^ h_low_l;

    uint32_t h_highX_xored = h_highXlow_h ^ h_highXlow_l;

    for (i = 0; i < count; i++, buf += 16) {

        ci_low = ghash->x_low ^ get64(buf + 8);

        ci_high = ghash->x_high ^ get64(buf);

        ci_low_h = (uint32_t)(ci_low >> 32);

        ci_low_l = (uint32_t)ci_low;

        ci_high_h = (uint32_t)(ci_high >> 32);

        ci_high_l = (uint32_t)ci_high;

        ci_highXlow_h = ci_high_h ^ ci_low_h;

        ci_highXlow_l = ci_high_l ^ ci_low_l;

        /* Do binary mult ghash->X = C * ghash->H (recursive Karatsuba). */

        bmul32(ci_high_h, h_high_h, &a_a_h, &a_a_l);

        bmul32(ci_high_l, h_high_l, &a_b_h, &a_b_l);

        bmul32(ci_high_h ^ ci_high_l, h_high_h ^ h_high_l, &a_c_h, &a_c_l);

        a_c_h ^= a_a_h ^ a_b_h;

        a_c_l ^= a_a_l ^ a_b_l;

        a_a_l ^= a_c_h;

        a_b_h ^= a_c_l;

        /* ci_high * h_high = a_a_h:a_a_l:a_b_h:a_b_l */

        bmul32(ci_low_h, h_low_h, &b_a_h, &b_a_l);

        bmul32(ci_low_l, h_low_l, &b_b_h, &b_b_l);

        bmul32(ci_low_h ^ ci_low_l, h_low_h ^ h_low_l, &b_c_h, &b_c_l);

        b_c_h ^= b_a_h ^ b_b_h;

        b_c_l ^= b_a_l ^ b_b_l;

        b_a_l ^= b_c_h;

        b_b_h ^= b_c_l;

        /* ci_low * h_low = b_a_h:b_a_l:b_b_h:b_b_l */

        bmul32(ci_highXlow_h, h_highXlow_h, &c_a_h, &c_a_l);

        bmul32(ci_highXlow_l, h_highXlow_l, &c_b_h, &c_b_l);

        bmul32(ci_highXlow_h ^ ci_highXlow_l, h_highX_xored, &c_c_h, &c_c_l);

        c_c_h ^= c_a_h ^ c_b_h;

        c_c_l ^= c_a_l ^ c_b_l;

        c_a_l ^= c_c_h;

        c_b_h ^= c_c_l;

        /* (ci_high ^ ci_low) * (h_high ^ h_low) = c_a_h:c_a_l:c_b_h:c_b_l */

        c_a_h ^= b_a_h ^ a_a_h;

        c_a_l ^= b_a_l ^ a_a_l;

        c_b_h ^= b_b_h ^ a_b_h;

        c_b_l ^= b_b_l ^ a_b_l;

        z_high_h = ((uint64_t)a_a_h << 32) | a_a_l;

        z_high_l = (((uint64_t)a_b_h << 32) | a_b_l) ^

                   (((uint64_t)c_a_h << 32) | c_a_l);

        z_low_h = (((uint64_t)b_a_h << 32) | b_a_l) ^

                  (((uint64_t)c_b_h << 32) | c_b_l);

        z_low_l = ((uint64_t)b_b_h << 32) | b_b_l;

        /* Shift one (multiply by x) as gcm spec is stupid. */

        z_high_h = z_high_h << 1 | z_high_l >> 63;

        z_high_l = z_high_l << 1 | z_low_h >> 63;

        z_low_h = z_low_h << 1 | z_low_l >> 63;

        z_low_l <<= 1;

        /* Reduce */

        z_low_h ^= (z_low_l << 63) ^ (z_low_l << 62) ^ (z_low_l << 57);

        z_high_h ^= z_low_h ^ (z_low_h >> 1) ^ (z_low_h >> 2) ^ (z_low_h >> 7);

        z_high_l ^= z_low_l ^ (z_low_l >> 1) ^ (z_low_l >> 2) ^ (z_low_l >> 7) ^

                    (z_low_h << 63) ^ (z_low_h << 62) ^ (z_low_h << 57);

        ghash->x_high = z_high_h;

        ghash->x_low = z_high_l;

    }

    return SECSuccess;

}

#endif /* HAVE_INT128_SUPPORT */

static SECStatus

gcm_zeroX(gcmHashContext *ghash)

{

    SECStatus rv = SECSuccess;

    if (ghash->hw) {

        rv = gcm_HashZeroX_hw(ghash);

    }

    ghash->x_high = ghash->x_low = 0;

    return rv;

}

/*

 * implement GCM GHASH using the freebl GHASH function. The gcm_HashMult

 * function always takes AES_BLOCK_SIZE lengths of data. gcmHash_Update will

 * format the data properly.

 */

SECStatus

gcmHash_Update(gcmHashContext *ghash, const unsigned char *buf,

               unsigned int len)

{

    unsigned int blocks;

    SECStatus rv;

    ghash->cLen += ((uint64_t)len * PR_BITS_PER_BYTE);

    /* first deal with the current buffer of data. Try to fill it out so

     * we can hash it */

    if (ghash->bufLen) {

        unsigned int needed = PR_MIN(len, AES_BLOCK_SIZE - ghash->bufLen);

        if (needed != 0) {

            PORT_Memcpy(ghash->buffer + ghash->bufLen, buf, needed);

        }

        buf += needed;

        len -= needed;

        ghash->bufLen += needed;

        if (len == 0) {

            /* didn't add enough to hash the data, nothing more do do */

            return SECSuccess;

        }

        PORT_Assert(ghash->bufLen == AES_BLOCK_SIZE);

        /* hash the buffer and clear it */

        rv = ghash->ghash_mul(ghash, ghash->buffer, 1);

        PORT_Memset(ghash->buffer, 0, AES_BLOCK_SIZE);

        ghash->bufLen = 0;

        if (rv != SECSuccess) {

            return SECFailure;

        }

    }

    /* now hash any full blocks remaining in the data stream */

    blocks = len / AES_BLOCK_SIZE;

    if (blocks) {

        rv = ghash->ghash_mul(ghash, buf, blocks);

        if (rv != SECSuccess) {

            return SECFailure;

        }

        buf += blocks * AES_BLOCK_SIZE;

        len -= blocks * AES_BLOCK_SIZE;

    }

    /* save any remainder in the buffer to be hashed with the next call */

    if (len != 0) {

        PORT_Memcpy(ghash->buffer, buf, len);

        ghash->bufLen = len;

    }

    return SECSuccess;

}

/*

 * write out any partial blocks zero padded through the GHASH engine,

 * save the lengths for the final completion of the hash

 */

static SECStatus

gcmHash_Sync(gcmHashContext *ghash)

{

    int i;

    SECStatus rv;

    /* copy the previous counter to the upper block */

    PORT_Memcpy(ghash->counterBuf, &ghash->counterBuf[GCM_HASH_LEN_LEN],

                GCM_HASH_LEN_LEN);

    /* copy the current counter in the lower block */

    for (i = 0; i < GCM_HASH_LEN_LEN; i++) {

        ghash->counterBuf[GCM_HASH_LEN_LEN + i] =

            (ghash->cLen >> ((GCM_HASH_LEN_LEN - 1 - i) * PR_BITS_PER_BYTE)) & 0xff;

    }

    ghash->cLen = 0;

    /* now zero fill the buffer and hash the last block */

    if (ghash->bufLen) {

        PORT_Memset(ghash->buffer + ghash->bufLen, 0, AES_BLOCK_SIZE - ghash->bufLen);

        rv = ghash->ghash_mul(ghash, ghash->buffer, 1);

        PORT_Memset(ghash->buffer, 0, AES_BLOCK_SIZE);

        ghash->bufLen = 0;

        if (rv != SECSuccess) {

            return SECFailure;

        }

    }

    return SECSuccess;

}

#define WRITE64(x, bytes)   \

    (bytes)[0] = (x) >> 56; \

    (bytes)[1] = (x) >> 48; \

    (bytes)[2] = (x) >> 40; \

    (bytes)[3] = (x) >> 32; \

    (bytes)[4] = (x) >> 24; \

    (bytes)[5] = (x) >> 16; \

    (bytes)[6] = (x) >> 8;  \

    (bytes)[7] = (x);

/*

 * This does the final sync, hashes the lengths, then returns

 * "T", the hashed output.

 */

SECStatus

gcmHash_Final(gcmHashContext *ghash, unsigned char *outbuf,

              unsigned int *outlen, unsigned int maxout)

{

    unsigned char T[MAX_BLOCK_SIZE];

    SECStatus rv;

    rv = gcmHash_Sync(ghash);

    if (rv != SECSuccess) {

        goto cleanup;

    }

    rv = ghash->ghash_mul(ghash, ghash->counterBuf,

                          (GCM_HASH_LEN_LEN * 2) / AES_BLOCK_SIZE);

    if (rv != SECSuccess) {

        goto cleanup;

    }

    if (ghash->hw) {

        rv = gcm_HashWrite_hw(ghash, T);

        if (rv != SECSuccess) {

            goto cleanup;

        }

    } else {

        WRITE64(ghash->x_low, T + 8);

        WRITE64(ghash->x_high, T);

    }

    if (maxout > AES_BLOCK_SIZE) {

        maxout = AES_BLOCK_SIZE;

    }

    PORT_Memcpy(outbuf, T, maxout);

    *outlen = maxout;

    rv = SECSuccess;

cleanup:

    PORT_SafeZero(T, sizeof(T));

    return rv;

}

SECStatus

gcmHash_Reset(gcmHashContext *ghash, const unsigned char *AAD,

              unsigned int AADLen)

{

    SECStatus rv;

    // Limit AADLen in accordance with SP800-38D

    if (sizeof(AADLen) >= 8) {

        unsigned long long AADLen_ull = AADLen;

        if (AADLen_ull > (1ULL << 61) - 1) {

            PORT_SetError(SEC_ERROR_INPUT_LEN);

            return SECFailure;

        }

    }

    ghash->cLen = 0;

    PORT_Memset(ghash->counterBuf, 0, GCM_HASH_LEN_LEN * 2);

    ghash->bufLen = 0;

    rv = gcm_zeroX(ghash);

    if (rv != SECSuccess) {

        return rv;

    }

    /* now kick things off by hashing the Additional Authenticated Data */

    if (AADLen != 0) {

        rv = gcmHash_Update(ghash, AAD, AADLen);

        if (rv != SECSuccess) {

            return SECFailure;

        }

        rv = gcmHash_Sync(ghash);

        if (rv != SECSuccess) {

            return SECFailure;

        }

    }

    return SECSuccess;

}

/**************************************************************************

 *           Now implement the GCM using gcmHash and CTR                  *

 **************************************************************************/

/* state to handle the full GCM operation (hash and counter) */

struct GCMContextStr {

    gcmHashContext *ghash_context;

    CTRContext ctr_context;

    freeblCipherFunc cipher;

    void *cipher_context;

    unsigned long tagBits;

    unsigned char tagKey[MAX_BLOCK_SIZE];

    PRBool ctr_context_init;

    gcmIVContext gcm_iv;

};

SECStatus gcm_InitCounter(GCMContext *gcm, const unsigned char *iv,

                          unsigned int ivLen, unsigned int tagBits,

                          const unsigned char *aad, unsigned int aadLen);

GCMContext *

GCM_CreateContext(void *context, freeblCipherFunc cipher,

                  const unsigned char *params)

{

    GCMContext *gcm = NULL;

    gcmHashContext *ghash = NULL;

    unsigned char H[MAX_BLOCK_SIZE];

    unsigned int tmp;

    const CK_NSS_GCM_PARAMS *gcmParams = (const CK_NSS_GCM_PARAMS *)params;

    SECStatus rv;

#ifdef DISABLE_HW_GCM

    const PRBool sw = PR_TRUE;

#else

    const PRBool sw = PR_FALSE;

#endif

    gcm = PORT_ZNew(GCMContext);

    if (gcm == NULL) {

        return NULL;

    }

    gcm->cipher = cipher;

    gcm->cipher_context = context;

    ghash = PORT_ZNewAligned(gcmHashContext, 16, mem);

    /* first plug in the ghash context */

    gcm->ghash_context = ghash;

    PORT_Memset(H, 0, AES_BLOCK_SIZE);

    rv = (*cipher)(context, H, &tmp, AES_BLOCK_SIZE, H, AES_BLOCK_SIZE, AES_BLOCK_SIZE);

    if (rv != SECSuccess) {

        goto loser;

    }

    rv = gcmHash_InitContext(ghash, H, sw);

    if (rv != SECSuccess) {

        goto loser;

    }

    gcm_InitIVContext(&gcm->gcm_iv);

    gcm->ctr_context_init = PR_FALSE;

    /* if gcmPara/ms is NULL, then we are creating an PKCS #11 MESSAGE

     * style context, in which we initialize the key once, then do separate

     * iv/aad's for each message. In that case we only initialize the key

     * and ghash. We initialize the counter in each separate message */

    if (gcmParams == NULL) {

        /* OK we are finished with init, if we are doing MESSAGE interface,

         * return from here */

        return gcm;

    }

    rv = gcm_InitCounter(gcm, gcmParams->pIv, gcmParams->ulIvLen,

                         gcmParams->ulTagBits, gcmParams->pAAD,

                         gcmParams->ulAADLen);

    if (rv != SECSuccess) {

        goto loser;

    }

    PORT_SafeZero(H, AES_BLOCK_SIZE);

    gcm->ctr_context_init = PR_TRUE;

    return gcm;

loser:

    PORT_SafeZero(H, AES_BLOCK_SIZE);

    if (ghash && ghash->mem) {

        void *mem = ghash->mem;

        PORT_SafeZero(ghash, sizeof(gcmHashContext));

        PORT_Free(mem);

    }

    if (gcm) {

        PORT_ZFree(gcm, sizeof(GCMContext));

    }

    return NULL;

}

static inline unsigned int

load32_be(const unsigned char *p)

{

    return ((unsigned int)p[0]) << 24 | p[1] << 16 | p[2] << 8 | p[3];

}

static inline void

store32_be(unsigned char *p, const unsigned int c)

{

    p[0] = (unsigned char)(c >> 24);

    p[1] = (unsigned char)(c >> 16);

    p[2] = (unsigned char)(c >> 8);

    p[3] = (unsigned char)c;

}

static inline void

gcm_ctr_xor(unsigned char *target, const unsigned char *x,

            const unsigned char *y, unsigned int count)

{

    for (unsigned int i = 0; i < count; i++) {

        target[i] = x[i] ^ y[i];

    }

}

static inline void

gcm_ctr_xor_block(unsigned char *target, const unsigned char *x,

                  const unsigned char *y)

{

#if defined(__ARM_NEON) || defined(__ARM_NEON__)

    vst1q_u8(target, veorq_u8(vld1q_u8(x), vld1q_u8(y)));

#else

    gcm_ctr_xor(target, x, y, AES_BLOCK_SIZE);

#endif

}

static SECStatus

gcm_CTR_Update(CTRContext *ctr, unsigned char *outbuf,

               unsigned int *outlen, unsigned int maxout,

               const unsigned char *inbuf, unsigned int inlen)

{

    PORT_Assert(ctr->counterBits == 32);

    PORT_Assert(0 < ctr->bufPtr && ctr->bufPtr <= AES_BLOCK_SIZE);

    // The AES-GCM message length limit is 2^32 - 2 blocks.

    const unsigned int blockLimit = 0xFFFFFFFEUL;

    unsigned char *const pCounter = ctr->counter + AES_BLOCK_SIZE - 4;

    unsigned int counter = load32_be(pCounter);

    // Calculate the number of times that the counter has already been incremented.

    unsigned char *const pCounterFirst = ctr->counterFirst + AES_BLOCK_SIZE - 4;

    unsigned int ticks = (counter - load32_be(pCounterFirst)) & 0xFFFFFFFFUL;

    // Get the number of bytes of keystream that are available in the internal buffer.

    const unsigned int bufBytes = AES_BLOCK_SIZE - ctr->bufPtr;

    // Calculate the number of times that we will increment the counter while

    // encrypting inbuf. We can encrypt bufBytes bytes of the input without

    // incrementing the counter.

    unsigned int newTicks;

    if (inlen < bufBytes) {

        newTicks = 0;

    } else if ((inlen - bufBytes) % AES_BLOCK_SIZE) {

        newTicks = ((inlen - bufBytes) / AES_BLOCK_SIZE) + 1;

    } else {

        newTicks = ((inlen - bufBytes) / AES_BLOCK_SIZE);

    }

    // Ensure that the counter will not exceed the limit.

    if (ticks > blockLimit - newTicks) {

        PORT_SetError(SEC_ERROR_INPUT_LEN);

        return SECFailure;

    }

    *outlen = inlen;

    if (maxout < inlen) {

        PORT_SetError(SEC_ERROR_OUTPUT_LEN);

        return SECFailure;

    }

    if (bufBytes) {

        unsigned int needed = PR_MIN(bufBytes, inlen);

        gcm_ctr_xor(outbuf, inbuf, ctr->buffer + ctr->bufPtr, needed);

        ctr->bufPtr += needed;

        outbuf += needed;

        inbuf += needed;

        inlen -= needed;

        PORT_Assert(inlen == 0 || ctr->bufPtr == AES_BLOCK_SIZE);

    }

    while (inlen >= AES_BLOCK_SIZE) {

        unsigned int tmp;

        SECStatus rv = (*ctr->cipher)(ctr->context, ctr->buffer, &tmp, AES_BLOCK_SIZE,

                                      ctr->counter, AES_BLOCK_SIZE, AES_BLOCK_SIZE);

        PORT_Assert(rv == SECSuccess);

        (void)rv;

        store32_be(pCounter, ++counter);

        gcm_ctr_xor_block(outbuf, inbuf, ctr->buffer);

        outbuf += AES_BLOCK_SIZE;

        inbuf += AES_BLOCK_SIZE;

        inlen -= AES_BLOCK_SIZE;

    }

    if (inlen) {

        unsigned int tmp;

        SECStatus rv = (*ctr->cipher)(ctr->context, ctr->buffer, &tmp, AES_BLOCK_SIZE,

                                      ctr->counter, AES_BLOCK_SIZE, AES_BLOCK_SIZE);

        PORT_Assert(rv == SECSuccess);

        (void)rv;

        store32_be(pCounter, ++counter);

        gcm_ctr_xor(outbuf, inbuf, ctr->buffer, inlen);

        ctr->bufPtr = inlen;

    }

    return SECSuccess;

}

SECStatus

gcm_InitCounter(GCMContext *gcm, const unsigned char *iv, unsigned int ivLen,

                unsigned int tagBits, const unsigned char *aad,

                unsigned int aadLen)

{

    gcmHashContext *ghash = gcm->ghash_context;

    unsigned int tmp;

    PRBool freeCtr = PR_FALSE;

    CK_AES_CTR_PARAMS ctrParams;

    SECStatus rv;

    /* Verify our parameters here */

    if (ivLen == 0) {

        PORT_SetError(SEC_ERROR_INVALID_ARGS);

        goto loser;

    }

    if (tagBits != 128 && tagBits != 120 &&

        tagBits != 112 && tagBits != 104 &&

        tagBits != 96 && tagBits != 64 &&

        tagBits != 32) {

        PORT_SetError(SEC_ERROR_INVALID_ARGS);

        goto loser;

    }

    /* fill in the Counter context */

    ctrParams.ulCounterBits = 32;

    PORT_Memset(ctrParams.cb, 0, sizeof(ctrParams.cb));

    if (ivLen == 12) {

        PORT_Memcpy(ctrParams.cb, iv, ivLen);

        ctrParams.cb[AES_BLOCK_SIZE - 1] = 1;

    } else {

        rv = gcmHash_Reset(ghash, NULL, 0);

        if (rv != SECSuccess) {

            goto loser;

        }

        rv = gcmHash_Update(ghash, iv, ivLen);

        if (rv != SECSuccess) {

            goto loser;

        }

        rv = gcmHash_Final(ghash, ctrParams.cb, &tmp, AES_BLOCK_SIZE);

        if (rv != SECSuccess) {

            goto loser;

        }

    }

    rv = CTR_InitContext(&gcm->ctr_context, gcm->cipher_context, gcm->cipher,

                         (unsigned char *)&ctrParams);

    if (rv != SECSuccess) {

        goto loser;

    }

    freeCtr = PR_TRUE;

    /* fill in the gcm structure */

    gcm->tagBits = tagBits; /* save for final step */

    /* calculate the final tag key. NOTE: gcm->tagKey is zero to start with.

     * if this assumption changes, we would need to explicitly clear it here */

    PORT_Memset(gcm->tagKey, 0, sizeof(gcm->tagKey));

    rv = gcm_CTR_Update(&gcm->ctr_context, gcm->tagKey, &tmp, AES_BLOCK_SIZE,

                        gcm->tagKey, AES_BLOCK_SIZE);

    if (rv != SECSuccess) {

        goto loser;

    }

    /* finally mix in the AAD data */

    rv = gcmHash_Reset(ghash, aad, aadLen);

    if (rv != SECSuccess) {

        goto loser;

    }

    PORT_SafeZero(&ctrParams, sizeof ctrParams);

    return SECSuccess;

loser:

    PORT_SafeZero(&ctrParams, sizeof ctrParams);

    if (freeCtr) {

        CTR_DestroyContext(&gcm->ctr_context, PR_FALSE);

    }

    return SECFailure;

}

void

GCM_DestroyContext(GCMContext *gcm, PRBool freeit)

{

    void *mem = gcm->ghash_context->mem;

    /* ctr_context is statically allocated and will be freed when we free

     * gcm. call their destroy functions to free up any locally

     * allocated data (like mp_int's) */

    if (gcm->ctr_context_init) {

        CTR_DestroyContext(&gcm->ctr_context, PR_FALSE);

    }

    PORT_Memset(gcm->ghash_context, 0, sizeof(gcmHashContext));

    PORT_Free(mem);

    PORT_Memset(&gcm->tagBits, 0, sizeof(gcm->tagBits));

    PORT_Memset(gcm->tagKey, 0, sizeof(gcm->tagKey));

    if (freeit) {

        PORT_Free(gcm);

    }

}

static SECStatus

gcm_GetTag(GCMContext *gcm, unsigned char *outbuf,

           unsigned int *outlen, unsigned int maxout)

{

    unsigned int tagBytes;

    unsigned int extra;

    unsigned int i;

    SECStatus rv;

    tagBytes = (gcm->tagBits + (PR_BITS_PER_BYTE - 1)) / PR_BITS_PER_BYTE;

    extra = tagBytes * PR_BITS_PER_BYTE - gcm->tagBits;

    if (outbuf == NULL) {

        *outlen = tagBytes;

        PORT_SetError(SEC_ERROR_OUTPUT_LEN);

        return SECFailure;

    }

    if (maxout < tagBytes) {

        *outlen = tagBytes;

        PORT_SetError(SEC_ERROR_OUTPUT_LEN);

        return SECFailure;

    }

    maxout = tagBytes;

    rv = gcmHash_Final(gcm->ghash_context, outbuf, outlen, maxout);

    if (rv != SECSuccess) {