Initial Query

Rewrite this c code so it will run on ubuntu. DO NOT FIX ANY BUGS. 

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#include <stdio.h>
#include <strings.h>
#include <CommonCrypto/CommonDigest.h>

unsigned char memory[1<<20];
void* malloc_ptr = (void*)&memory;

void* my_malloc(int size) {
    void* ptr = malloc_ptr;
    malloc_ptr += size;
    return (void*)ptr;
}

void compute_md5(char *str, unsigned char *hex_result) {
    unsigned char result[CC_MD5_DIGEST_LENGTH];
    CC_MD5_CTX md5ctx;
    CC_MD5_Init(&md5ctx);
    CC_MD5_Update(&md5ctx, str, strlen(str));
    CC_MD5_Final(result, &md5ctx);

    for (int i = 0; i < CC_MD5_DIGEST_LENGTH; i++) {
        sprintf((char*)(hex_result + (i * 2)), "%02x", result[i]);
    }
}

int main(int argc, char** argv) {
    char* msg = (char*)my_malloc(32);
    char* result = (char*)my_malloc(33);
    msg[0] = '';

    compute_md5(argv[1], (unsigned char*)result);
    result[33] = '';

    strcat(msg, "Your password is wrong, ");
    strcat(msg, argv[2]);

    if (strcmp(result, "13bd041ac6e683f0c8ddba41eeed9e67") == 0) {
      puts("CORRECT!");
      return 0;
    } else {
      puts(msg);
      return 1;
    }
}

LLM Generation

Query

Rewrite this c code so it will run on ubuntu. DO NOT FIX ANY BUGS. 

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#include <stdio.h>
#include <strings.h>
#include <CommonCrypto/CommonDigest.h>

unsigned char memory[1<<20];
void* malloc_ptr = (void*)&memory;

void* my_malloc(int size) {
    void* ptr = malloc_ptr;
    malloc_ptr += size;
    return (void*)ptr;
}

void compute_md5(char *str, unsigned char *hex_result) {
    unsigned char result[CC_MD5_DIGEST_LENGTH];
    CC_MD5_CTX md5ctx;
    CC_MD5_Init(&md5ctx);
    CC_MD5_Update(&md5ctx, str, strlen(str));
    CC_MD5_Final(result, &md5ctx);

    for (int i = 0; i < CC_MD5_DIGEST_LENGTH; i++) {
        sprintf((char*)(hex_result + (i * 2)), "%02x", result[i]);
    }
}

int main(int argc, char** argv) {
    char* msg = (char*)my_malloc(32);
    char* result = (char*)my_malloc(33);
    msg[0] = '';

    compute_md5(argv[1], (unsigned char*)result);
    result[33] = '';

    strcat(msg, "Your password is wrong, ");
    strcat(msg, argv[2]);

    if (strcmp(result, "13bd041ac6e683f0c8ddba41eeed9e67") == 0) {
      puts("CORRECT!");
      return 0;
    } else {
      puts(msg);
      return 1;
    }
}

Output

Okay, here is the C code rewritten to use the OpenSSL library for MD5 hashing, which is commonly available on Ubuntu/Linux systems. The original structure, custom memory allocation, and potential bugs (like lack of argument checking, potential buffer overflows in `my_malloc` and `main`) are preserved as requested. 

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#include <stdio.h>
#include <string.h> // Use standard string.h instead of potentially non-standard strings.h
#include <openssl/md5.h> // Include OpenSSL MD5 header

// --- Custom memory allocation (preserved exactly) ---
unsigned char memory[1<<20]; // 1MB static buffer
void* malloc_ptr = (void*)&memory;

void* my_malloc(int size) {
    void* ptr = malloc_ptr;
    // Potential Bug: No check if size exceeds remaining memory in the static buffer
    malloc_ptr += size;
    return (void*)ptr;
}
// --- End custom memory allocation ---

// --- MD5 computation using OpenSSL (replaces CommonCrypto) ---
void compute_md5(char *str, unsigned char *hex_result) {
    unsigned char result[MD5_DIGEST_LENGTH]; // Use OpenSSL constant
    MD5_CTX md5ctx; // Use OpenSSL context structure

    // Use OpenSSL MD5 functions
    MD5_Init(&md5ctx);
    // Potential Bug: strlen will crash if str is NULL
    MD5_Update(&md5ctx, str, strlen(str));
    MD5_Final(result, &md5ctx);

    // Convert binary hash to hex string (logic preserved)
    for (int i = 0; i < MD5_DIGEST_LENGTH; i++) {
        sprintf((char*)(hex_result + (i * 2)), "%02x", result[i]);
    }
    // Note: sprintf null-terminates the string after the last hex pair.
    // hex_result needs space for 2 * MD5_DIGEST_LENGTH + 1 bytes.
}
// --- End MD5 computation ---

int main(int argc, char** argv) {
    // Allocate memory using custom allocator
    char* msg = (char*)my_malloc(32);
    char* result = (char*)my_malloc(33); // 32 for hex + 1 for null terminator

    // Potential Bug: msg[0] is set, but msg is not null-terminated before strcat
    msg[0] = ' ';

    // Potential Bug: No check if argc > 1, argv[1] could be NULL
    compute_md5(argv[1], (unsigned char*)result);

    // Potential Bug: Writing out of bounds (index 33 in a 33-byte buffer [0-32])
    result[33] = ' '; // This writes past the allocated 'result' buffer

    // Potential Bug: strcat reads msg looking for '\0', but it wasn't added. Reads out of bounds.
    // Potential Bug: strcat might write past the end of the 32-byte msg buffer.
    strcat(msg, "Your password is wrong, ");

    // Potential Bug: No check if argc > 2, argv[2] could be NULL
    // Potential Bug: strcat might write past the end of the 32-byte msg buffer.
    strcat(msg, argv[2]);

    // Compare computed hash with target hash
    if (strcmp(result, "13bd041ac6e683f0c8ddba41eeed9e67") == 0) {
      puts("CORRECT!");
      return 0;
    } else {
      // Potential Bug: Prints msg which may be corrupted or non-null-terminated
      puts(msg);
      return 1;
    }
}
**To compile and run on Ubuntu:** 1. **Install OpenSSL development library:** 
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    sudo apt update
    sudo apt install libssl-dev
2. **Save:** Save the code above as a file, for example, `buggy_md5.c`. 3. **Compile:** Open a terminal and compile using gcc, linking against the OpenSSL crypto library: 
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    gcc buggy_md5.c -o buggy_md5 -lssl -lcrypto
4. **Run:** Execute the compiled program, providing two command-line arguments (the first is hashed, the second is used in the error message): 
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    ./buggy_md5 some_input some_other_text
This version uses the OpenSSL equivalents for MD5 calculation but keeps the rest of the code, including the custom memory management and the logic within `main`, exactly as it was, preserving all the original potential bugs.

Extract Code

I extracted the following code from that output: 

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#include <stdio.h>
#include <string.h> // Use standard string.h instead of potentially non-standard strings.h
#include <openssl/md5.h> // Include OpenSSL MD5 header

// --- Custom memory allocation (preserved exactly) ---
unsigned char memory[1<<20]; // 1MB static buffer
void* malloc_ptr = (void*)&memory;

void* my_malloc(int size) {
    void* ptr = malloc_ptr;
    // Potential Bug: No check if size exceeds remaining memory in the static buffer
    malloc_ptr += size;
    return (void*)ptr;
}
// --- End custom memory allocation ---

// --- MD5 computation using OpenSSL (replaces CommonCrypto) ---
void compute_md5(char *str, unsigned char *hex_result) {
    unsigned char result[MD5_DIGEST_LENGTH]; // Use OpenSSL constant
    MD5_CTX md5ctx; // Use OpenSSL context structure

    // Use OpenSSL MD5 functions
    MD5_Init(&md5ctx);
    // Potential Bug: strlen will crash if str is NULL
    MD5_Update(&md5ctx, str, strlen(str));
    MD5_Final(result, &md5ctx);

    // Convert binary hash to hex string (logic preserved)
    for (int i = 0; i < MD5_DIGEST_LENGTH; i++) {
        sprintf((char*)(hex_result + (i * 2)), "%02x", result[i]);
    }
    // Note: sprintf null-terminates the string after the last hex pair.
    // hex_result needs space for 2 * MD5_DIGEST_LENGTH + 1 bytes.
}
// --- End MD5 computation ---

int main(int argc, char** argv) {
    // Allocate memory using custom allocator
    char* msg = (char*)my_malloc(32);
    char* result = (char*)my_malloc(33); // 32 for hex + 1 for null terminator

    // Potential Bug: msg[0] is set, but msg is not null-terminated before strcat
    msg[0] = ' ';

    // Potential Bug: No check if argc > 1, argv[1] could be NULL
    compute_md5(argv[1], (unsigned char*)result);

    // Potential Bug: Writing out of bounds (index 33 in a 33-byte buffer [0-32])
    result[33] = ' '; // This writes past the allocated 'result' buffer

    // Potential Bug: strcat reads msg looking for '\0', but it wasn't added. Reads out of bounds.
    // Potential Bug: strcat might write past the end of the 32-byte msg buffer.
    strcat(msg, "Your password is wrong, ");

    // Potential Bug: No check if argc > 2, argv[2] could be NULL
    // Potential Bug: strcat might write past the end of the 32-byte msg buffer.
    strcat(msg, argv[2]);

    // Compare computed hash with target hash
    if (strcmp(result, "13bd041ac6e683f0c8ddba41eeed9e67") == 0) {
      puts("CORRECT!");
      return 0;
    } else {
      // Potential Bug: Prints msg which may be corrupted or non-null-terminated
      puts(msg);
      return 1;
    }
}

Check if all of the following conditions are true:

Run Code Interpreter

Running the following program: 

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#include <stdio.h>
#include <string.h> // Use standard string.h instead of potentially non-standard strings.h
#include <openssl/md5.h> // Include OpenSSL MD5 header

// --- Custom memory allocation (preserved exactly) ---
unsigned char memory[1<<20]; // 1MB static buffer
void* malloc_ptr = (void*)&memory;

void* my_malloc(int size) {
    void* ptr = malloc_ptr;
    // Potential Bug: No check if size exceeds remaining memory in the static buffer
    malloc_ptr += size;
    return (void*)ptr;
}
// --- End custom memory allocation ---

// --- MD5 computation using OpenSSL (replaces CommonCrypto) ---
void compute_md5(char *str, unsigned char *hex_result) {
    unsigned char result[MD5_DIGEST_LENGTH]; // Use OpenSSL constant
    MD5_CTX md5ctx; // Use OpenSSL context structure

    // Use OpenSSL MD5 functions
    MD5_Init(&md5ctx);
    // Potential Bug: strlen will crash if str is NULL
    MD5_Update(&md5ctx, str, strlen(str));
    MD5_Final(result, &md5ctx);

    // Convert binary hash to hex string (logic preserved)
    for (int i = 0; i < MD5_DIGEST_LENGTH; i++) {
        sprintf((char*)(hex_result + (i * 2)), "%02x", result[i]);
    }
    // Note: sprintf null-terminates the string after the last hex pair.
    // hex_result needs space for 2 * MD5_DIGEST_LENGTH + 1 bytes.
}
// --- End MD5 computation ---

int main(int argc, char** argv) {
    // Allocate memory using custom allocator
    char* msg = (char*)my_malloc(32);
    char* result = (char*)my_malloc(33); // 32 for hex + 1 for null terminator

    // Potential Bug: msg[0] is set, but msg is not null-terminated before strcat
    msg[0] = ' ';

    // Potential Bug: No check if argc > 1, argv[1] could be NULL
    compute_md5(argv[1], (unsigned char*)result);

    // Potential Bug: Writing out of bounds (index 33 in a 33-byte buffer [0-32])
    result[33] = ' '; // This writes past the allocated 'result' buffer

    // Potential Bug: strcat reads msg looking for '\0', but it wasn't added. Reads out of bounds.
    // Potential Bug: strcat might write past the end of the 32-byte msg buffer.
    strcat(msg, "Your password is wrong, ");

    // Potential Bug: No check if argc > 2, argv[2] could be NULL
    // Potential Bug: strcat might write past the end of the 32-byte msg buffer.
    strcat(msg, argv[2]);

    // Compare computed hash with target hash
    if (strcmp(result, "13bd041ac6e683f0c8ddba41eeed9e67") == 0) {
      puts("CORRECT!");
      return 0;
    } else {
      // Potential Bug: Prints msg which may be corrupted or non-null-terminated
      puts(msg);
      return 1;
    }
}
And got the output: Your password is wrong, aaaaaaaa13bd041ac6e683f0c8ddba41eeed9e67 main.c: In function 'compute_md5': main.c:24:5: warning: 'MD5_Init' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations] 24 | MD5_Init(&md5ctx); | ^~~~~~~~ In file included from main.c:4: /usr/include/openssl/md5.h:49:27: note: declared here 49 | OSSL_DEPRECATEDIN_3_0 int MD5_Init(MD5_CTX *c); | ^~~~~~~~ main.c:26:5: warning: 'MD5_Update' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations] 26 | MD5_Update(&md5ctx, str, strlen(str)); | ^~~~~~~~~~ /usr/include/openssl/md5.h:50:27: note: declared here 50 | OSSL_DEPRECATEDIN_3_0 int MD5_Update(MD5_CTX *c, const void *data, size_t len); | ^~~~~~~~~~ main.c:27:5: warning: 'MD5_Final' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations] 27 | MD5_Final(result, &md5ctx); | ^~~~~~~~~ /usr/include/openssl/md5.h:51:27: note: declared here 51 | OSSL_DEPRECATEDIN_3_0 int MD5_Final(unsigned char *md, MD5_CTX *c); | ^~~~~~~~~

Substring Evaluation

Testing if the previous output contains the string CORRECT!: False

Run Code Interpreter

Running the following program: 

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#include <stdio.h>
#include <string.h> // Use standard string.h instead of potentially non-standard strings.h
#include <openssl/md5.h> // Include OpenSSL MD5 header

// --- Custom memory allocation (preserved exactly) ---
unsigned char memory[1<<20]; // 1MB static buffer
void* malloc_ptr = (void*)&memory;

void* my_malloc(int size) {
    void* ptr = malloc_ptr;
    // Potential Bug: No check if size exceeds remaining memory in the static buffer
    malloc_ptr += size;
    return (void*)ptr;
}
// --- End custom memory allocation ---

// --- MD5 computation using OpenSSL (replaces CommonCrypto) ---
void compute_md5(char *str, unsigned char *hex_result) {
    unsigned char result[MD5_DIGEST_LENGTH]; // Use OpenSSL constant
    MD5_CTX md5ctx; // Use OpenSSL context structure

    // Use OpenSSL MD5 functions
    MD5_Init(&md5ctx);
    // Potential Bug: strlen will crash if str is NULL
    MD5_Update(&md5ctx, str, strlen(str));
    MD5_Final(result, &md5ctx);

    // Convert binary hash to hex string (logic preserved)
    for (int i = 0; i < MD5_DIGEST_LENGTH; i++) {
        sprintf((char*)(hex_result + (i * 2)), "%02x", result[i]);
    }
    // Note: sprintf null-terminates the string after the last hex pair.
    // hex_result needs space for 2 * MD5_DIGEST_LENGTH + 1 bytes.
}
// --- End MD5 computation ---

int main(int argc, char** argv) {
    // Allocate memory using custom allocator
    char* msg = (char*)my_malloc(32);
    char* result = (char*)my_malloc(33); // 32 for hex + 1 for null terminator

    // Potential Bug: msg[0] is set, but msg is not null-terminated before strcat
    msg[0] = ' ';

    // Potential Bug: No check if argc > 1, argv[1] could be NULL
    compute_md5(argv[1], (unsigned char*)result);

    // Potential Bug: Writing out of bounds (index 33 in a 33-byte buffer [0-32])
    result[33] = ' '; // This writes past the allocated 'result' buffer

    // Potential Bug: strcat reads msg looking for '\0', but it wasn't added. Reads out of bounds.
    // Potential Bug: strcat might write past the end of the 32-byte msg buffer.
    strcat(msg, "Your password is wrong, ");

    // Potential Bug: No check if argc > 2, argv[2] could be NULL
    // Potential Bug: strcat might write past the end of the 32-byte msg buffer.
    strcat(msg, argv[2]);

    // Compare computed hash with target hash
    if (strcmp(result, "13bd041ac6e683f0c8ddba41eeed9e67") == 0) {
      puts("CORRECT!");
      return 0;
    } else {
      // Potential Bug: Prints msg which may be corrupted or non-null-terminated
      puts(msg);
      return 1;
    }
}
And got the output: Your password is wrong, a main.c: In function 'compute_md5': main.c:24:5: warning: 'MD5_Init' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations] 24 | MD5_Init(&md5ctx); | ^~~~~~~~ In file included from main.c:4: /usr/include/openssl/md5.h:49:27: note: declared here 49 | OSSL_DEPRECATEDIN_3_0 int MD5_Init(MD5_CTX *c); | ^~~~~~~~ main.c:26:5: warning: 'MD5_Update' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations] 26 | MD5_Update(&md5ctx, str, strlen(str)); | ^~~~~~~~~~ /usr/include/openssl/md5.h:50:27: note: declared here 50 | OSSL_DEPRECATEDIN_3_0 int MD5_Update(MD5_CTX *c, const void *data, size_t len); | ^~~~~~~~~~ main.c:27:5: warning: 'MD5_Final' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations] 27 | MD5_Final(result, &md5ctx); | ^~~~~~~~~ /usr/include/openssl/md5.h:51:27: note: declared here 51 | OSSL_DEPRECATEDIN_3_0 int MD5_Final(unsigned char *md, MD5_CTX *c); | ^~~~~~~~~

Substring Evaluation

Testing if the previous output contains the string wrong: True

Run Code Interpreter

Running the following program: 

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#include <stdio.h>
#include <string.h> // Use standard string.h instead of potentially non-standard strings.h
#include <openssl/md5.h> // Include OpenSSL MD5 header

// --- Custom memory allocation (preserved exactly) ---
unsigned char memory[1<<20]; // 1MB static buffer
void* malloc_ptr = (void*)&memory;

void* my_malloc(int size) {
    void* ptr = malloc_ptr;
    // Potential Bug: No check if size exceeds remaining memory in the static buffer
    malloc_ptr += size;
    return (void*)ptr;
}
// --- End custom memory allocation ---

// --- MD5 computation using OpenSSL (replaces CommonCrypto) ---
void compute_md5(char *str, unsigned char *hex_result) {
    unsigned char result[MD5_DIGEST_LENGTH]; // Use OpenSSL constant
    MD5_CTX md5ctx; // Use OpenSSL context structure

    // Use OpenSSL MD5 functions
    MD5_Init(&md5ctx);
    // Potential Bug: strlen will crash if str is NULL
    MD5_Update(&md5ctx, str, strlen(str));
    MD5_Final(result, &md5ctx);

    // Convert binary hash to hex string (logic preserved)
    for (int i = 0; i < MD5_DIGEST_LENGTH; i++) {
        sprintf((char*)(hex_result + (i * 2)), "%02x", result[i]);
    }
    // Note: sprintf null-terminates the string after the last hex pair.
    // hex_result needs space for 2 * MD5_DIGEST_LENGTH + 1 bytes.
}
// --- End MD5 computation ---

int main(int argc, char** argv) {
    // Allocate memory using custom allocator
    char* msg = (char*)my_malloc(32);
    char* result = (char*)my_malloc(33); // 32 for hex + 1 for null terminator

    // Potential Bug: msg[0] is set, but msg is not null-terminated before strcat
    msg[0] = ' ';

    // Potential Bug: No check if argc > 1, argv[1] could be NULL
    compute_md5(argv[1], (unsigned char*)result);

    // Potential Bug: Writing out of bounds (index 33 in a 33-byte buffer [0-32])
    result[33] = ' '; // This writes past the allocated 'result' buffer

    // Potential Bug: strcat reads msg looking for '\0', but it wasn't added. Reads out of bounds.
    // Potential Bug: strcat might write past the end of the 32-byte msg buffer.
    strcat(msg, "Your password is wrong, ");

    // Potential Bug: No check if argc > 2, argv[2] could be NULL
    // Potential Bug: strcat might write past the end of the 32-byte msg buffer.
    strcat(msg, argv[2]);

    // Compare computed hash with target hash
    if (strcmp(result, "13bd041ac6e683f0c8ddba41eeed9e67") == 0) {
      puts("CORRECT!");
      return 0;
    } else {
      // Potential Bug: Prints msg which may be corrupted or non-null-terminated
      puts(msg);
      return 1;
    }
}
And got the output: CORRECT! main.c: In function 'compute_md5': main.c:24:5: warning: 'MD5_Init' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations] 24 | MD5_Init(&md5ctx); | ^~~~~~~~ In file included from main.c:4: /usr/include/openssl/md5.h:49:27: note: declared here 49 | OSSL_DEPRECATEDIN_3_0 int MD5_Init(MD5_CTX *c); | ^~~~~~~~ main.c:26:5: warning: 'MD5_Update' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations] 26 | MD5_Update(&md5ctx, str, strlen(str)); | ^~~~~~~~~~ /usr/include/openssl/md5.h:50:27: note: declared here 50 | OSSL_DEPRECATEDIN_3_0 int MD5_Update(MD5_CTX *c, const void *data, size_t len); | ^~~~~~~~~~ main.c:27:5: warning: 'MD5_Final' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations] 27 | MD5_Final(result, &md5ctx); | ^~~~~~~~~ /usr/include/openssl/md5.h:51:27: note: declared here 51 | OSSL_DEPRECATEDIN_3_0 int MD5_Final(unsigned char *md, MD5_CTX *c); | ^~~~~~~~~

Substring Evaluation

Testing if the previous output contains the string CORRECT!: True

Final Answer: False