diff options
Diffstat (limited to 'security/nss/lib/freebl/aeskeywrap.c')
| -rw-r--r-- | security/nss/lib/freebl/aeskeywrap.c | 268 |
1 files changed, 256 insertions, 12 deletions
diff --git a/security/nss/lib/freebl/aeskeywrap.c b/security/nss/lib/freebl/aeskeywrap.c index 3d2c9e448..09c0667c7 100644 --- a/security/nss/lib/freebl/aeskeywrap.c +++ b/security/nss/lib/freebl/aeskeywrap.c @@ -9,6 +9,8 @@ #include "stubs.h" #endif +#include <stddef.h> + #include "prcpucfg.h" #if defined(IS_LITTLE_ENDIAN) || defined(SHA_NO_LONG_LONG) #define BIG_ENDIAN_WITH_64_BIT_REGISTERS 0 @@ -196,11 +198,33 @@ set_t(unsigned char *pt, unsigned long t) #endif +static void +encode_PRUint32_BE(unsigned char *data, PRUint32 val) +{ + size_t i; + for (i = 0; i < sizeof(PRUint32); i++) { + data[i] = PORT_GET_BYTE_BE(val, i, sizeof(PRUint32)); + } +} + +static PRUint32 +decode_PRUint32_BE(unsigned char *data) +{ + PRUint32 val = 0; + size_t i; + + for (i = 0; i < sizeof(PRUint32); i++) { + val = (val << PR_BITS_PER_BYTE) | data[i]; + } + return val; +} + /* -** Perform AES key wrap. +** Perform AES key wrap W function. ** "cx" the context +** "iv" the iv is concatenated to the plain text for for executing the function ** "output" the output buffer to store the encrypted data. -** "outputLen" how much data is stored in "output". Set by the routine +** "pOutputLen" how much data is stored in "output". Set by the routine ** after some data is stored in output. ** "maxOutputLen" the maximum amount of data that can ever be ** stored in "output" @@ -208,9 +232,9 @@ set_t(unsigned char *pt, unsigned long t) ** "inputLen" the amount of input data */ extern SECStatus -AESKeyWrap_Encrypt(AESKeyWrapContext *cx, unsigned char *output, - unsigned int *pOutputLen, unsigned int maxOutputLen, - const unsigned char *input, unsigned int inputLen) +AESKeyWrap_W(AESKeyWrapContext *cx, unsigned char *iv, unsigned char *output, + unsigned int *pOutputLen, unsigned int maxOutputLen, + const unsigned char *input, unsigned int inputLen) { PRUint64 *R = NULL; unsigned int nBlocks; @@ -251,7 +275,7 @@ AESKeyWrap_Encrypt(AESKeyWrapContext *cx, unsigned char *output, /* ** 1) Initialize variables. */ - memcpy(&A, cx->iv, AES_KEY_WRAP_IV_BYTES); + memcpy(&A, iv, AES_KEY_WRAP_IV_BYTES); memcpy(&R[1], input, inputLen); #if BIG_ENDIAN_WITH_64_BIT_REGISTERS t = 0; @@ -294,10 +318,12 @@ AESKeyWrap_Encrypt(AESKeyWrapContext *cx, unsigned char *output, #undef A /* -** Perform AES key unwrap. +** Perform AES key wrap W^-1 function. ** "cx" the context +** "iv" the input IV to verify against. If NULL, then skip verification. +** "ivOut" the output buffer to store the IV (optional). ** "output" the output buffer to store the decrypted data. -** "outputLen" how much data is stored in "output". Set by the routine +** "pOutputLen" how much data is stored in "output". Set by the routine ** after some data is stored in output. ** "maxOutputLen" the maximum amount of data that can ever be ** stored in "output" @@ -305,9 +331,10 @@ AESKeyWrap_Encrypt(AESKeyWrapContext *cx, unsigned char *output, ** "inputLen" the amount of input data */ extern SECStatus -AESKeyWrap_Decrypt(AESKeyWrapContext *cx, unsigned char *output, - unsigned int *pOutputLen, unsigned int maxOutputLen, - const unsigned char *input, unsigned int inputLen) +AESKeyWrap_Winv(AESKeyWrapContext *cx, unsigned char *iv, + unsigned char *ivOut, unsigned char *output, + unsigned int *pOutputLen, unsigned int maxOutputLen, + const unsigned char *input, unsigned int inputLen) { PRUint64 *R = NULL; unsigned int nBlocks; @@ -378,11 +405,14 @@ AESKeyWrap_Decrypt(AESKeyWrapContext *cx, unsigned char *output, ** 3) Output the results. */ if (s == SECSuccess) { - int bad = memcmp(&B[0], cx->iv, AES_KEY_WRAP_IV_BYTES); + int bad = (iv) && memcmp(&B[0], iv, AES_KEY_WRAP_IV_BYTES); if (!bad) { memcpy(output, &R[1], outLen); if (pOutputLen) *pOutputLen = outLen; + if (ivOut) { + memcpy(ivOut, &B[0], AES_KEY_WRAP_IV_BYTES); + } } else { s = SECFailure; PORT_SetError(SEC_ERROR_BAD_DATA); @@ -396,3 +426,217 @@ AESKeyWrap_Decrypt(AESKeyWrapContext *cx, unsigned char *output, return s; } #undef A + +/* +** Perform AES key wrap. +** "cx" the context +** "output" the output buffer to store the encrypted data. +** "pOutputLen" how much data is stored in "output". Set by the routine +** after some data is stored in output. +** "maxOutputLen" the maximum amount of data that can ever be +** stored in "output" +** "input" the input data +** "inputLen" the amount of input data +*/ +extern SECStatus +AESKeyWrap_Encrypt(AESKeyWrapContext *cx, unsigned char *output, + unsigned int *pOutputLen, unsigned int maxOutputLen, + const unsigned char *input, unsigned int inputLen) +{ + return AESKeyWrap_W(cx, cx->iv, output, pOutputLen, maxOutputLen, + input, inputLen); +} + +/* +** Perform AES key unwrap. +** "cx" the context +** "output" the output buffer to store the decrypted data. +** "pOutputLen" how much data is stored in "output". Set by the routine +** after some data is stored in output. +** "maxOutputLen" the maximum amount of data that can ever be +** stored in "output" +** "input" the input data +** "inputLen" the amount of input data +*/ +extern SECStatus +AESKeyWrap_Decrypt(AESKeyWrapContext *cx, unsigned char *output, + unsigned int *pOutputLen, unsigned int maxOutputLen, + const unsigned char *input, unsigned int inputLen) +{ + return AESKeyWrap_Winv(cx, cx->iv, NULL, output, pOutputLen, maxOutputLen, + input, inputLen); +} + +#define BLOCK_PAD_POWER2(x, bs) (((bs) - ((x) & ((bs)-1))) & ((bs)-1)) +#define AES_KEY_WRAP_ICV2 0xa6, 0x59, 0x59, 0xa6 +#define AES_KEY_WRAP_ICV2_INT32 0xa65959a6 +#define AES_KEY_WRAP_ICV2_LEN 4 + +/* +** Perform AES key wrap with padding. +** "cx" the context +** "output" the output buffer to store the encrypted data. +** "pOutputLen" how much data is stored in "output". Set by the routine +** after some data is stored in output. +** "maxOutputLen" the maximum amount of data that can ever be +** stored in "output" +** "input" the input data +** "inputLen" the amount of input data +*/ +extern SECStatus +AESKeyWrap_EncryptKWP(AESKeyWrapContext *cx, unsigned char *output, + unsigned int *pOutputLen, unsigned int maxOutputLen, + const unsigned char *input, unsigned int inputLen) +{ + unsigned int padLen = BLOCK_PAD_POWER2(inputLen, AES_KEY_WRAP_BLOCK_SIZE); + unsigned int paddedInputLen = inputLen + padLen; + unsigned int outLen = paddedInputLen + AES_KEY_WRAP_BLOCK_SIZE; + unsigned char iv[AES_BLOCK_SIZE] = { AES_KEY_WRAP_ICV2 }; + unsigned char *newBuf; + SECStatus rv; + + *pOutputLen = outLen; + if (maxOutputLen < outLen) { + PORT_SetError(SEC_ERROR_OUTPUT_LEN); + return SECFailure; + } + PORT_Assert((AES_KEY_WRAP_ICV2_LEN + sizeof(PRUint32)) == AES_KEY_WRAP_BLOCK_SIZE); + encode_PRUint32_BE(iv + AES_KEY_WRAP_ICV2_LEN, inputLen); + + /* If we can fit in an AES Block, just do and AES Encrypt, + * iv is big enough to handle this on the stack, so no need to allocate + */ + if (outLen == AES_BLOCK_SIZE) { + PORT_Assert(inputLen <= AES_KEY_WRAP_BLOCK_SIZE); + PORT_Memset(iv + AES_KEY_WRAP_BLOCK_SIZE, 0, AES_KEY_WRAP_BLOCK_SIZE); + PORT_Memcpy(iv + AES_KEY_WRAP_BLOCK_SIZE, input, inputLen); + rv = AES_Encrypt(&cx->aescx, output, pOutputLen, maxOutputLen, iv, + outLen); + PORT_Memset(iv, 0, sizeof(iv)); + return rv; + } + + /* add padding to our input block */ + newBuf = PORT_ZAlloc(paddedInputLen); + if (newBuf == NULL) { + return SECFailure; + } + PORT_Memcpy(newBuf, input, inputLen); + + rv = AESKeyWrap_W(cx, iv, output, pOutputLen, maxOutputLen, + newBuf, paddedInputLen); + PORT_ZFree(newBuf, paddedInputLen); + /* a little overkill, we only need to clear out the length, but this + * is easier to verify we got it all */ + PORT_Memset(iv, 0, sizeof(iv)); + return rv; +} + +/* +** Perform AES key unwrap with padding. +** "cx" the context +** "output" the output buffer to store the decrypted data. +** "pOutputLen" how much data is stored in "output". Set by the routine +** after some data is stored in output. +** "maxOutputLen" the maximum amount of data that can ever be +** stored in "output" +** "input" the input data +** "inputLen" the amount of input data +*/ +extern SECStatus +AESKeyWrap_DecryptKWP(AESKeyWrapContext *cx, unsigned char *output, + unsigned int *pOutputLen, unsigned int maxOutputLen, + const unsigned char *input, unsigned int inputLen) +{ + unsigned int padLen; + unsigned int padLen2; + unsigned int outLen; + unsigned int paddedLen; + unsigned int good; + unsigned char *newBuf = NULL; + unsigned char *allocBuf = NULL; + int i; + unsigned char iv[AES_BLOCK_SIZE]; + PRUint32 magic; + SECStatus rv = SECFailure; + + paddedLen = inputLen - AES_KEY_WRAP_BLOCK_SIZE; + /* unwrap the padded result */ + if (inputLen == AES_BLOCK_SIZE) { + rv = AES_Decrypt(&cx->aescx, iv, &outLen, inputLen, input, inputLen); + newBuf = &iv[AES_KEY_WRAP_BLOCK_SIZE]; + outLen -= AES_KEY_WRAP_BLOCK_SIZE; + } else { + /* if the caller supplied enough space to hold the unpadded buffer, + * we can unwrap directly into that unpadded buffer. Otherwise + * we allocate a buffer that can hold the padding, and we'll copy + * the result in a later step */ + newBuf = output; + if (maxOutputLen < paddedLen) { + allocBuf = newBuf = PORT_Alloc(paddedLen); + if (!allocBuf) { + return SECFailure; + } + } + /* We pass NULL for the first IV argument because we don't know + * what the IV has since in includes the length, so we don't have + * Winv verify it. We pass iv in the second argument to get the + * iv, which we verify below before we return anything */ + rv = AESKeyWrap_Winv(cx, NULL, iv, newBuf, &outLen, + paddedLen, input, inputLen); + } + if (rv != SECSuccess) { + goto loser; + } + rv = SECFailure; + if (outLen != paddedLen) { + PORT_SetError(SEC_ERROR_LIBRARY_FAILURE); + goto loser; + } + + /* we verify the result in a constant time manner */ + /* verify ICV magic */ + magic = decode_PRUint32_BE(iv); + good = PORT_CT_EQ(magic, AES_KEY_WRAP_ICV2_INT32); + /* fetch and verify plain text length */ + outLen = decode_PRUint32_BE(iv + AES_KEY_WRAP_ICV2_LEN); + good &= PORT_CT_LE(outLen, paddedLen); + /* now verify the padding */ + padLen = paddedLen - outLen; + padLen2 = BLOCK_PAD_POWER2(outLen, AES_KEY_WRAP_BLOCK_SIZE); + good &= PORT_CT_EQ(padLen, padLen2); + for (i = 0; i < AES_KEY_WRAP_BLOCK_SIZE; i++) { + unsigned int doTest = PORT_CT_GT(padLen, i); + unsigned int result = PORT_CT_ZERO(newBuf[paddedLen - i - 1]); + good &= PORT_CT_SEL(doTest, result, PORT_CT_TRUE); + } + + /* now if anything was wrong, fail. At this point we will leak timing + * information, but we also 'leak' the error code as well. */ + if (!good) { + PORT_SetError(SEC_ERROR_BAD_DATA); + goto loser; + } + + /* now copy out the result */ + *pOutputLen = outLen; + if (maxOutputLen < outLen) { + PORT_SetError(SEC_ERROR_OUTPUT_LEN); + goto loser; + } + if (output != newBuf) { + PORT_Memcpy(output, newBuf, outLen); + } + rv = SECSuccess; +loser: + /* if we failed, make sure we don't return any data to the user */ + if ((rv != SECSuccess) && (output == newBuf)) { + PORT_Memset(newBuf, 0, paddedLen); + } + /* clear out CSP sensitive data from the heap and stack */ + if (allocBuf) { + PORT_ZFree(allocBuf, paddedLen); + } + PORT_Memset(iv, 0, sizeof(iv)); + return rv; +} |